Sample records for uhmwpe tibial inserts

  1. Effect of e-beam sterilization on the in vivo performance of conventional UHMWPE tibial plates for total knee arthroplasty.

    PubMed

    Tone, Shine; Hasegawa, Masahiro; Pezzotti, Giuseppe; Puppulin, Leonardo; Sudo, Akihiro

    2017-06-01

    Although the introduction of highly cross-linked polyethylene is effective in reducing the amount of wear, there are still major concerns regarding the use of this material in total knee arthroplasty (TKA), essentially due to the reduction of fatigue resistance and toughness. Monitoring the in vivo performance of different types of UHMWPE is a much needed task to tackle the lack of information on which should be the most reliable choice for TKA. The present study was aimed at investigating the mid-term degradation of electron beam sterilized conventional UHMWPE tibial plates. Visual inspection enabled to grade the surface damage of 12 retrievals according to the Hood's score: the total wear damage correlates to the in vivo time (Spearman's ρ=0.681, p<0.05) and BMI (ρ=0.834, p<0.001). Surface degradation was less severe than that quantified in similar studies on γ-sterilized UHMWPE. Raman and infra-red spectroscopies were utilized to unfold the microstructural modifications. In the load zone, polyethylene whitened damage regions were noticed in the inserts implanted longer than 1year, in which oxidation index (OI) is clearly higher than 1 (max 8). The maximum OI (ρ=0.802, p<0.005) and α c (ρ=0.816, p<0.005) correlate to the implantation time in the load zone. The crystallinity increased along with the extent of oxidation. Concentration of absorbed species from synovial fluid is higher in the contact zone and correlates to maximum OI (Spearman's ρ=0.699, p=0.011). Absorption was promoted in the contact area by the mechanical action of the femoral counterpart and it exacerbated the oxidative degradation in retrievals with high concentration of absorbed species. In the non-load zone, mild but detectable oxidation was observed, probably due to free radicals trapped after sterilization. Although several clinical studies on retrieved tibial bearings have been published so far, monitoring and comparing the in vivo performance of different types of UHMWPE is still a

  2. Fractography and oxidative analysis of gamma inert sterilized posterior-stabilized tibial insert post fractures: report of two cases.

    PubMed

    Ansari, Farzana; Chang, Jennifer; Huddleston, James; Van Citters, Douglas; Ries, Michael; Pruitt, Lisa

    2013-12-01

    Highly crosslinked ultra-high molecular weight polyethylene (UHMWPE) has shown success in reducing wear in hip arthroplasty but there remains skepticism about its use in Total Knee Replacement (TKR) inserts that are known to experience fatigue loading and higher local cyclic contact stresses. Two Legacy Posterior-Stabilized (LPS) Zimmer NexGen tibial implants sterilized by gamma irradiation in an inert environment with posts that fractured in vivo were analyzed. Failure mechanisms were determined using optical and scanning electron microscopy along with oxidative analysis via Fourier Transform Infra-Red (FTIR) spectroscopy. Micrographs of one retrieval revealed fatigue crack initiation on opposite sides of the post and quasi-brittle micromechanisms of crack propagation. FTIR of this retrieval revealed no oxidation. The fracture surface image of the second retrieval indicated a brittle fracture process and FTIR revealed oxidation in the explant. These two cases suggest that crosslinking of UHMWPE as a manufacturing process or sterilization method in conjunction with designs that incorporate high stress concentrations, such as the tibial post, may reduce material strength. Moreover, free radicals generated from ionizing radiation can render the polymer susceptible to oxidative embrittlement. Our findings suggest that tibial post fractures may be the results of in vivo oxidation and low level crosslinking. These and previous reports of fractured crosslinked UHMWPE devices implores caution when used with high stress concentrations, particularly when considering the potential for in vivo oxidation in TKR. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Histological analysis of the tibial anterior cruciate ligament insertion.

    PubMed

    Oka, Shinya; Schuhmacher, Peter; Brehmer, Axel; Traut, Ulrike; Kirsch, Joachim; Siebold, Rainer

    2016-03-01

    This study was performed to investigate the morphology of the tibial anterior cruciate ligament (ACL) by histological assessment. The native (undissected) tibial ACL insertion of six fresh-frozen cadaveric knees was cut into four sagittal sections parallel to the long axis of the medial tibial spine. For histological evaluation, the slices were stained with haematoxylin and eosin, Safranin O and Russell-Movat pentachrome. All slices were digitalized and analysed at a magnification of 20×. The anterior tibial ACL insertion was bordered by a bony anterior ridge. The most medial ACL fibres inserted from the medial tibial spine and were adjacent to the articular cartilage of the medial tibial plateau. Parts of the bony insertions of the anterior and posterior horns of the lateral meniscus were in close contact with the lateral part of the tibial ACL insertion. A small fat pad was located just posterior to the functional ACL fibres. The anterior-posterior length of the medial ACL insertion was an average of 10.8 ± 1.1 mm compared with the lateral, which was only 6.2 ± 1.1 mm (p < 0.001). There were no central or posterolateral inserting ACL fibres. The shape of the bony tibial ACL insertion was 'duck-foot-like'. In contrast to previous findings, the functional mid-substance fibres arose from the most posterior part of the 'duck-foot' in a flat and 'c-shaped' way. The most anterior part of the tibial ACL insertion was bordered by a bony anterior ridge and the most medial by the medial tibial spine. No posterolateral fibres nor ACL bundles have been found histologically. This histological investigation may improve our understanding of the tibial ACL insertion and may provide important information for anatomical ACL reconstruction.

  4. Histological Analysis of the Tibial Anterior Cruciate Ligament Insertion

    PubMed Central

    Siebold, Rainer; Oka, Shinya; Traut, Ulrike; Schuhmacher, Peter; Kirsch, Joachim

    2017-01-01

    Objective: To describe the morphology of the tibial ACL insertion by histological assessment in the sagittal plane. Methods: For histology the native (undissected) tibial ACL insertion of 6 fresh-frozen cadaveric knees was cut into 4 sagittal sections parallel to the long axis of the medial tibial spine. The slices were stained with hematoxylin and eosin, Safranin O and Russell-Movat pentachrome. All slices were digitalized and analyzed at a magnification of ×20. Results: From medial to lateral the anterior-posterior lengths of the ACL insertion were an average of 10.2, 9.3, 7.6 and 5.8 mm. The anterior margin of the tibial ACL insertion raised from an anterior ridge. The most medial ACL fibers rose along with a peak of the anterior part of the medial tibial spine in which the direct insertion was adjacent to the articular cartilage. Parts of the bony insertions of the anterior and posterior horns of the lateral meniscus were in close contact to the lateral ACL insertion. A small fat pad was located just posterior to the tibial ACL insertion. There were no central or posterolateral inserting ACL fibers in the area intercondylaris anterior. Conclusion: The functional intraligamentous midsubstance ACL fibers arose from the most posterior part of its bony tibial insertion in a flat and “C-shape” way. The anterior border of this functional ACL started from a bony ‘anterior ridge’ and the medial border was along with a peak of the medial tibial spine.

  5. A Novel Method to Assess Wear Rates of Retrieved Tibial Inserts Following in-vivo Use

    NASA Astrophysics Data System (ADS)

    Paniogue, Tanille J.

    Ultra-high molecular weight polyethylene (UHMWPE) on cobalt chrome is the bearing couple of choice for total knee arthroplasty. The number of patients undergoing total knee arthroplasty has been steadily growing and is projected to continue increasing rapidly in the near future. Many of these patients are younger and more active and therefore need a longer lasting device. However, many of these devices fail prematurely and often the primary reason for failure and ultimately revision is due to wear related issues. Therefore, examining how wear rates of the UHMWPE tibial insert change during in-vivo use can help elucidate the mechanisms of accelerated wear and hopefully aid in finding solutions to combat wear related failures. Different crosslinking treatments have been employed by manufacturers to improve wear resistance of the polyethylene. While this has been shown to be an effective way to reduce wear, crosslinking has led to other issues such as oxidative instability and a decline in mechanical properties. The purpose of this body of work is to examine how changes in oxidation, after in-vivo use, affect wear resistance. A novel testing method was developed to test the native articular surface from retrieved tibial inserts in a laboratory Pin-on-Disk (POD) simulator. The method was validated using short-duration implant articular surfaces and non-articular control pins. In the absence of high surface oxidation or severe surface damage, the articular surface pins had comparable steady state wear rates to their bulk counterparts. Tests of devices with longer in-vivo service show chemical changes consistent with a free-radical mediated oxidation mechanism. Tribological assessment of the articular surfaces shows increasing wear rates as a function of oxidation. While this relationship has been hypothesized in the literature, these experiments represent the first physical demonstration of the phenomenon. The wear mechanism is further explored through infrared

  6. Ideal tibial intramedullary nail insertion point varies with tibial rotation.

    PubMed

    Walker, Richard M; Zdero, Rad; McKee, Michael D; Waddell, James P; Schemitsch, Emil H

    2011-12-01

    The aim of the study was to investigate how superior entry point varies with tibial rotation and to identify landmarks that can be used to identify suitable radiographs for successful intramedullary nail insertion. The proximal tibia and knee were imaged for 12 cadaveric limbs undergoing 5° increments of internal and external rotation. Medial and lateral arthrotomies were performed, the ideal superior entry point was identified, and a 2-mm Kirschner wire inserted. A second Kirschner wire was sequentially placed at the 5-mm and then the 10-mm position, both medial and lateral to the initial Kirschner wire. Radiographs of the knee were obtained for all increments. The changing position of the ideal nail insertion point was recorded. A 30° arc (range, 25°-40°) provided a suitable anteroposterior radiograph. On the neutral anteroposterior radiograph, the Kirschner wire was 54% ± 1.5% (range, 51-56%) from the medial edge of the tibial plateau. For every 5° of rotation, the Kirschner wire moved 3% of the plateau width. During external rotation, a misleading medial entry point was obtained. A fibular bisector line correlated with an entry point that was ideal or up to 5 mm lateral to this but never medial. The film that best showed the fibular bisector line was between 0° and 10° of internal rotation of the tibia. The fibula head bisector line can be used to avoid choosing external rotation views and, thus, avoid medial insertion points. The current results may help the surgeon prevent malalignment during intramedullary nailing in proximal tibial fractures.

  7. Flat midsubstance of the anterior cruciate ligament with tibial "C"-shaped insertion site.

    PubMed

    Siebold, Rainer; Schuhmacher, Peter; Fernandez, Francis; Śmigielski, Robert; Fink, Christian; Brehmer, Axel; Kirsch, Joachim

    2015-11-01

    This anatomical cadaver study was performed to investigate the flat appearance of the midsubstance shape of the anterior cruciate ligament (ACL) and its tibial "C"-shaped insertion site. The ACL midsubstance and the tibial ACL insertion were dissected in 20 cadaveric knees (n = 6 fresh frozen and n = 14 paraffined). Magnifying spectacles were used for all dissections. Morphometric measurements were performed using callipers and on digital photographs. In all specimens, the midsubstance of the ACL was flat with a mean width of 9.9 mm, thickness of 3.9 mm and cross-sectional area of 38.7 mm(2). The "direct" "C"-shaped tibial insertion runs from along the medial tibial spine to the anterior aspect of the lateral meniscus. The mean width (length) of the "C" was 12.6 mm, its thickness 3.3 mm and area 31.4 mm(2). The centre of the "C" was the bony insertion of the anterior root of the lateral meniscus overlayed by fat and crossed by the ACL. No posterolateral (PL) inserting ACL fibres were found. Together with the larger "indirect" part (area 79.6 mm(2)), the "direct" one formed a "duck-foot"-shaped footprint. The tibial ACL midsubstance and tibial "C"-shaped insertion are flat and are resembling a "ribbon". The centre of the "C" is the bony insertion of the anterior root of the lateral meniscus. There are no central or PL inserting ACL fibres. Anatomical ACL reconstruction may therefore require a flat graft and a "C"-shaped tibial footprint reconstruction with an anteromedial bone tunnel for single bundle and an additional posteromedial bone tunnel for double bundle.

  8. Nontraumatic tibial polyethylene insert cone fracture in mobile-bearing posterior-stabilized total knee arthroplasty.

    PubMed

    Tanikake, Yohei; Hayashi, Koji; Ogawa, Munehiro; Inagaki, Yusuke; Kawate, Kenji; Tomita, Tetsuya; Tanaka, Yasuhito

    2016-12-01

    A 72-year-old male patient underwent mobile-bearing posterior-stabilized total knee arthroplasty for osteoarthritis. He experienced a nontraumatic polyethylene tibial insert cone fracture 27 months after surgery. Scanning electron microscopy of the fracture surface of the tibial insert cone suggested progress of ductile breaking from the posterior toward the anterior of the cone due to repeated longitudinal bending stress, leading to fatigue breaking at the anterior side of the cone, followed by the tibial insert cone fracture at the anterior side of the cone, resulting in fracture at the base of the cone. This analysis shows the risk of tibial insert cone fracture due to longitudinal stress in mobile-bearing posterior-stabilized total knee arthroplasty in which an insert is designed to highly conform to the femoral component.

  9. Wear Measurement of Highly Cross-Linked UHMWPE Using a 7Be Tracer Implantation Technique

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wimmer, Markus; Laurent, Michael P.; Dwivedi, Yash

    2013-01-29

    The very low wear rates achieved with the current highly cross-linked ultra-high molecular weight polyethylenes (UHMWPE) used in joint prostheses have proven to be difficult to measure accurately by gravimetry. Tracer methods are therefore being explored. The purpose of this study was to effect a proof-of-concept on the use of the radioactive tracer beryllium-7 (7Be) for the determination of wear in a highly cross-linked orthopedic UHMWPE. Three crosslinked and four conventional UHMWPE pins made from compression-molded GUR 1050, were activated with 109 to 1010 7Be nuclei using a new implantation setup that produced a homogenous distribution of implanted nuclei upmore » to 8.5 μm below the surface. The pins were tested for wear in a six-station pin-on-flat apparatus for up to 7.1 million cycles (178 km). A Germanium gamma detector was employed to determine activity loss of the UHMWPE pins at preset intervals during the wear test. The wear of the cross-linked UHMWPE pins was readily detected and estimated to be 17 ± 3 μg/Mc. The conventional-to-cross-linked ratio of the wear rates was 13.1 ± 0.8, in the expected range for these materials. It was estimated that implantation reduced the average wear rate by approximately 20%, and the oxidative degradation damage from implantation was negligible. Future applications of this tracer technology may include the analysis of location-specific wear, such as loss of material in the post or backside of a tibial insert.« less

  10. The transverse ligament as a landmark for tibial sagittal insertions of the anterior cruciate ligament: a cadaveric study.

    PubMed

    Kongcharoensombat, Wirat; Ochi, Mitsuo; Abouheif, Mohamed; Adachi, Nobuo; Ohkawa, Shingo; Kamei, Goki; Okuhara, Atushi; Shibuya, Hoyatoshi; Niimoto, Takuya; Nakasa, Tomoyuki; Nakamae, Atsuo; Deie, Masataka

    2011-10-01

    The purpose of this study was to determine the relation between the position of the transverse ligament, the anterior edge of the anterior cruciate ligament (ACL) tibial footprint, and the center of the ACL tibial insertion. We used arthroscopy for localization of the anatomic landmarks, followed by insertions of guide pins under direct visualization, and then the position of these guide pins was checked on plain lateral radiographs. The transverse ligament and the anterior aspect of the ACL tibial footprint were identified by arthroscopy in 20 unpaired cadaveric knees (10 left and 10 right). Guide pins were inserted with tibial ACL adapter drill guides under direct observation at the transverse ligament, the anterior aspect of the tibial footprint, and the center of tibial insertion of the ACL. Then, plain lateral radiographs of specimens were taken. The Amis and Jakob line was used to define the attachment of the ACL tibial insertion and the transverse ligament. A sagittal percentage of the location of the insertion point was determined and calculated from the anterior margin of the tibia in the anteroposterior direction. The transverse ligament averaged 21.20% ± 4.1%, the anterior edge of the ACL tibial insertion averaged 21.60% ± 4.0%, and the center of the ACL tibial insertion averaged 40.30% ± 4.8%. There were similar percent variations between the transverse ligament and the anterior edge of the ACL tibial insertion, with no significant difference between them (P = .38). Intraobserver and interobserver reliability was high, with small standard errors of measurement. This study shows that the transverse ligament coincides with the anterior edge of the ACL tibial footprint in the sagittal plane. The transverse ligament can be considered as a new landmark for tibial tunnel positioning during anatomic ACL reconstruction. Copyright © 2011 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  11. Metrology to quantify wear and creep of polyethylene tibial knee inserts.

    PubMed

    Muratoglu, Orhun K; Perinchief, Rebecca S; Bragdon, Charles R; O'Connor, Daniel O; Konrad, Reto; Harris, William H

    2003-05-01

    Assessment of damage on articular surfaces of ultrahigh molecular weight polyethylene tibial knee inserts primarily has been limited to qualitative methods, such as visual observation and classification of features such as pitting, delamination, and subsurface cracking. Semiquantitative methods also have been proposed to determine the linear penetration and volume of the scar that forms on articular surfaces of tibial knee inserts. The current authors report a new metrologic method that uses a coordinate measuring machine to quantify the dimensions of this scar. The articular surface of the insert is digitized with the coordinate measuring machine before and after regular intervals of testing on a knee simulator. The volume and linear penetration of the scar are calculated by mathematically taking the difference between the digitized surface maps of the worn and unworn articular surfaces. Three conventional polyethylene tibial knee inserts of a posterior cruciate-sparing design were subjected to five million cycles of normal gait on a displacement-driven knee wear simulator in bovine serum. A metrologic method was used to calculate creep and wear contributions to the scar formation on each tibial plateau. Weight loss of the inserts was determined gravimetrically with the appropriate correction for fluid absorption. The total average wear volume was 43 +/- 9 and 41 +/- 4 mm3 measured by the metrologic and gravimetric methods, respectively. The wear rate averaged 8.3 +/- 0.9 and 8.5 +/- 1.6 mm3 per million cycles measured by the metrologic and gravimetric methods, respectively. These comparisons reflected strong agreement between the metrologic and gravimetric methods.

  12. Wear Measurement of Highly Cross-linked UHMWPE using a 7Be Tracer Implantation Technique

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wimmer, Markus A.; Laurent, Michael P.; Dwivedi, Yasha

    2013-01-01

    The very low wear rates achieved with the current highly cross-linked ultrahigh molecular weight polyethylenes (UHMWPE) used in joint prostheses have proven to be difficult to measure accurately by gravimetry. Tracer methods are there- fore being explored. The purpose of this study was to perform a proof-of-concept experiment on the use of the radioactive tracer beryllium-7 (7Be) for the determination of in vitro wear in a highly cross-linked orthopedic UHMWPE. Three cross-linked and four conventional UHMWPE pins made from compression- molded GUR 1050, were activated with 109 to 1010 7Be nuclei using a new implantation setup that produced a homogenousmore » distribution of implanted nuclei up to 8.5 lm below the surface. The pins were tested for wear in a six-station pin-on-flat appara- tus for up to 7.1 million cycles (178 km). A Germanium gamma detector was employed to determine activity loss of the UHMWPE pins at preset intervals during the wear test. The wear of the cross-linked UHMWPE pins was readily detected and esti- mated to be 17 6 3 lg per million cycles. The conventional-to- cross-linked ratio of the wear rates was 13.1 6 0.8, in the expected range for these materials. Oxidative degradation dam- age from implantation was negligible; however, a weak depend- ence of wear on implantation dose was observed limiting the number of radioactive tracer atoms that can be introduced. Future applications of this tracer technology may include the analysis of location-specific wear, such as loss of material in the post or backside of a tibial insert.« less

  13. Area of the tibial insertion site of the anterior cruciate ligament as a predictor for graft size.

    PubMed

    Guenther, Daniel; Irarrázaval, Sebastian; Albers, Marcio; Vernacchia, Cara; Irrgang, James J; Musahl, Volker; Fu, Freddie H

    2017-05-01

    To determine the distribution of different sizes of the area of the tibial insertion site among the population and to evaluate whether preoperative MRI measurements correlate with intraoperative findings to enable preoperative planning of the required graft size to cover the tibial insertion site sufficiently. The hypothesis was that the area of the tibial insertion site varies among individuals and that there is good agreement between MRI and intraoperative measurements. Intraoperative measurements of the tibial insertion site were taken on 117 patients. Three measurements were taken in each plane building a grid to cover the tibial insertion site as closely as possible. The mean of the three measurements in each plane was used for determination of the area. Two orthopaedic surgeons, who were blinded to the intraoperative measurements, took magnetic resonance imaging (MRI) measurements of the area of the tibial insertion site at two different time points. The intraoperative measured mean area was 123.8 ± 21.5 mm 2 . The mean area was 132.8 ± 15.7 mm 2 (rater 1) and 136.7 ± 15.4 mm 2 (rater 2) when determined using MRI. The size of the area was approximately normally distributed. Inter-rater (0.89; 95 % CI 0.84, 0.92; p < 0.001) and intrarater reliability (rater 1: 0.97; 95 % CI 0.95, 0.98; p < 0.001; rater 2: 0.95; 95 % CI 0.92, 0.96; p < 0.001) demonstrated excellent test-retest reliability. There was good agreement between MRI and intraoperative measurement of tibial insertion site area (ICCs rater 1: 0.80; 95 % CI 0.71, 0.87; p < 0.001; rater 2: 0.87; 95 % CI 0.81, 0.91; p < 0.001). The tibial insertion site varies in size and shape. Preoperative determination of the area using MRI is repeatable and enables planning of graft choice and size to optimally cover the tibial insertion site. III.

  14. The developmental morphology of a "periosteal" ligament insertion: growth and maturation of the tibial insertion of the rabbit medial collateral ligament.

    PubMed

    Matyas, J R; Bodie, D; Andersen, M; Frank, C B

    1990-05-01

    The structural properties of ligament insertions change dramatically during growth and maturation, but little is known about their developmental anatomy. This study describes and quantifies changes in the gross and microscopic anatomy of the tibial insertion of the rabbit medial collateral ligament (MCL) during development and at skeletal maturity. Eighty animals were used for growth and descriptive studies. From this group, 27 animals, ranging in age from 1 to 24 months, were injected with fluorescent bone markers and their tibial insertions were processed undecalcified for histology. Sections were examined by polarized light and fluorescence microscopy to identify matrix and cells and to quantify mineral formation. Results showed that animals achieved histological skeletal maturity between 9 and 12 months of age. Body weights were a poor index of skeletal maturity. The tibial insertion was composed of five tissue layers, which changed proportions during growth and maturation. In immature animals, MCL fibers entered the periosteum; in older animals, MCL fibers were cemented to the tibia by advancing mineral. The tibial attachment of the MCL was thus transferred from the periosteum to the cortex during growth, suggesting that the term "periosteal insertion" is imprecise in adults. The hypothesis is put forward that these structural changes account for the reported increase in tensile failure of this insertion near skeletal maturity.

  15. Strain measurements of the tibial insert of a knee prosthesis using a knee motion simulator.

    PubMed

    Sera, Toshihiro; Iwai, Yuya; Yamazaki, Takaharu; Tomita, Tetsuya; Yoshikawa, Hideki; Naito, Hisahi; Matsumoto, Takeshi; Tanaka, Masao

    2017-12-01

    The longevity of a knee prosthesis is influenced by the wear of the tibial insert due to its posture and movement. In this study, we assumed that the strain on the tibial insert is one of the main reasons for its wear and investigated the influence of the knee varus-valgus angles on the mechanical stress of the tibial insert. Knee prosthesis motion was simulated using a knee motion simulator based on a parallel-link six degrees-of-freedom actuator and the principal strain and pressure distribution of the tibial insert were measured. In particular, the early stance phase obtained from in vivo X-ray images was examined because the knee is applied to the largest load during extension/flexion movement. The knee varus-valgus angles were 0° (neutral alignment), 3°, and 5° malalignment. Under a neutral orientation, the pressure was higher at the middle and posterior condyles. The first and second principal strains were larger at the high and low pressure areas, respectively. Even for a 3° malalignment, the load was concentrated at one condyle and the positive first principal strain increased dramatically at the high pressure area. The negative second principal strain was large at the low pressure area on the other condyle. The maximum equivalent strain was 1.3-2.1 times larger at the high pressure area. For a 5° malalignment, the maximum equivalent strain increased slightly. These strain and pressure measurements can provide the mechanical stress of the tibial insert in detail for determining the longevity of an artificial knee joint.

  16. Tibial interface wear in retrieved total knee components and correlations with modular insert motion.

    PubMed

    Rao, Anand R; Engh, Gerard A; Collier, Matthew B; Lounici, Smain

    2002-10-01

    Wear occurring at the interface between the polyethylene insert and metal baseplate of a modular tibial component has become an increasingly common finding at the time of revision total knee arthroplasty. Although this so-called backside wear on retrieved polyethylene inserts has been evaluated in prior studies, wear on retrieved metal baseplates has not been described, to our knowledge. The purposes of the present study were to characterize backside wear on retrieved polyethylene inserts and on the mating surfaces of their corresponding baseplates and to investigate if there is a relationship between backside wear and relative motion of the modular elements. Twenty-nine retrieved modular tibial components of twelve fixed-bearing designs were analyzed in vitro with regard to backside wear and relative motion between the polyethylene insert and the metal baseplate. We graded the backside of each polyethylene insert and the mating surface of the metal baseplate for wear with use of a scoring system that consisted of three modes of wear and three levels of severity of wear. Relative motion between the insert and the baseplate was measured in the transverse plane with use of a mechanical testing machine. These measurements were used to compute the insert motion index, which served to quantify unrestricted motion of the insert with respect to the baseplate. The mean insert motion index for the tibial components was 416 micro m (range, 104 micro m to 760 micro m). On a wear-grading scale ranging from 0 to 54 (with 0 indicating no wear), the mean backside wear score was 30 (range, 12 to 48) for the inserts and 28 (range, 7 to 51) for the baseplates. Insert motion was positively correlated with backside polyethylene wear (p = 0.003) and baseplate wear (p < 0.001). Baseplate wear was strongly correlated with backside polyethylene wear (p < 0.001). Backside wear was correlated with the relative motion between the polyethylene insert and the metal baseplate. New locking

  17. Regional fibrocartilage variations in human anterior cruciate ligament tibial insertion: a histological three-dimensional reconstruction.

    PubMed

    Dai, Can; Guo, Lin; Yang, Liu; Wu, Yi; Gou, Jingyue; Li, Bangchun

    2015-02-01

    We studied anterior cruciate ligament (ACL) tibial insertion architecture in humans and investigated regional differences that could suggest unequal force transmission from ligament to bone. ACL tibial insertions were processed histologically. With Photoshop software, digital images taken from the histological slides were collaged, contour lines were drawn, and different gray values were filled based on the structure. The data were exported to Amira software for three-dimensional reconstruction. The uncalcified fibrocartilage (UF) layer was divided into three regions: lateral, medial and posterior according to the architecture. The UF zone was significantly thicker laterally than medially or posteriorly (p < 0.05). Similarly, the calcified fibrocartilage (CF) thickness was significantly greater in the lateral part of the enthesis compared to the medial and posterior parts (p < 0.05). The UF quantity (more UF laterally) corresponding to the CF quantity (more CF laterally) at the ACL tibial insertion provides further evidence suggesting that the load transferred from the ACL to the tibia was greater laterally than medially and posteriorly.

  18. Oxidation resistant peroxide cross-linked UHMWPE produced by blending and surface diffusion

    NASA Astrophysics Data System (ADS)

    Gul, Rizwan M.; Oral, Ebru; Muratoglu, Orhun K.

    2014-06-01

    Ultra-high molecular weight polyethylene (UHMWPE) has been widely used as acetabular cup in total hip replacement (THR) and tibial component in total knee replacement (TKR). Crosslinking of UHMWPE has been successful used to improve its wear performance leading to longer life of orthopedic implants. Crosslinking can be performed by radiation or organic peroxides. Peroxide crosslinking is a convenient process as it does not require specialized equipment and the level of crosslinking can be manipulated by changing the amount of peroxide added. However, there is concern about the long-term stability of these materials due to possible presence of by-products. Vitamin E has been successfully used to promote long-term oxidative stability of UHMWPE. In this study, UHMWPE has been crosslinked using organic peroxide in the presence of Vitamin E to produce an oxidation resistant peroxide crosslinked material. Crosslinking was performed both in bulk by mixing peroxide and resin, and only on the surface using diffusion of peroxides.The results show that UHMWPE can be crosslinked using organic peroxides in the presence of vitamin E by both methods. However, the level of crosslinking decreases with the increase in vitamin E content. The wear resistance increases with the increase in crosslink density, and oxidation resistance significantly increases due to the presence of vitamin E.

  19. Variation in the shape of the tibial insertion site of the anterior cruciate ligament: classification is required.

    PubMed

    Guenther, Daniel; Irarrázaval, Sebastian; Nishizawa, Yuichiro; Vernacchia, Cara; Thorhauer, Eric; Musahl, Volker; Irrgang, James J; Fu, Freddie H

    2017-08-01

    To propose a classification system for the shape of the tibial insertion site (TIS) of the anterior cruciate ligament (ACL) and to demonstrate the intra- and inter-rater agreement of this system. Due to variation in shape and size, different surgical approaches may be feasible to improve reconstruction of the TIS. One hundred patients with a mean age of 26 ± 11 years were included. The ACL was cut arthroscopically at the base of the tibial insertion site. Arthroscopic images were taken from the lateral and medial portal. Images were de-identified and duplicated. Two blinded observers classified the tibial insertion site according to a classification system. The tibial insertion site was classified as type I (elliptical) in 51 knees (51 %), type II (triangular) in 33 knees (33 %) and type III (C-shaped) in 16 knees (16 %). There was good agreement between raters when viewing the insertion site from the lateral portal (κ = 0.65) as well as from the medial portal (κ = 0.66). Intra-rater reliability was good to excellent. Agreement in the description of the insertion site between the medial and lateral portals was good for rater 1 and good for rater 2 (κ = 0.74 and 0.77, respectively). There is variation in the shape of the ACL TIS. The classification system is a repeatable and reliable tool to summarize the shape of the TIS using three common patterns. For clinical relevance, different shapes may require different types of reconstruction to ensure proper footprint restoration. Consideration of the individual TIS shape is required to prevent iatrogenic damage of adjacent structures like the menisci. III.

  20. [Mobility of a polyethylene tibial insert in a mobile total knee prosthesis].

    PubMed

    Castel, E; Roger, B; Camproux, A; Saillant, G

    1999-03-01

    We have studied the mobility of a mobile tibial implant in total knee arthroplasty (TKA) by a radiographical evaluation. We analyzed mobility of the polyethylene tibial insert of 15 "G2S" TKA implanted for one year or more. We established a dynamic radiographical evaluation. We used 3 weight-bearing radiographs: AP in extension and two lateral (one in extension and one at 90 degrees of flexion), two AP with femoral internal and external rotation, 2 strict lateral X-rays in neutral rotation in antero-posterior replacement with a 25 kilograms strength Telos, and 2 AP in varus and valgus with Telos. Wilcoxon's test and Fisher's exact test were used for statistical evaluation. Our study demonstrated preservation of the polyethylene mobility in tibial TKA implant in all movements: in rotation, in antero-posterior translation with Telos, and even in antero-posterior translation during physiological condition with flexion-extension weight-bearing radiographs. Statistical tests were very significant. We noticed that flexion induced anterior translation of tibial polyethylene when PCL was preserved. This study answered to our question whether mobility of TKA tibial implant persists after implantation. This mobility should reduce loosening forces to the tibia and stress in the polyethylene component. Now we have to determine the amplitude of mobility required to reach this objective.

  1. Suprapatellar Versus Infrapatellar Tibial Nail Insertion: A Prospective Randomized Control Pilot Study.

    PubMed

    Chan, Daniel S; Serrano-Riera, Rafael; Griffing, Rebecca; Steverson, Barbara; Infante, Anthony; Watson, David; Sagi, H Claude; Sanders, Roy W

    2016-03-01

    The purpose of this OTA-approved pilot study was to compare the clinical and functional outcomes of the knee joint after infrapatellar (IP) versus suprapatellar (SP) tibial nail insertion. Prospective, randomized. Level I trauma center. After institutional review board approval, skeletally mature patients with OTA 42 tibial shaft fractures were randomized into either an IP or SP nail insertion group after informed consent was obtained. The SP also underwent prenail and postnail insertion patella-femoral (PF) joint arthroscopy. Patients underwent follow-up (6 weeks, 3, 6, and 12 months) with standard radiographs, as well as visual analog score and pain diagram documentation. At the 6-month and 12-month visits, knee function questionnaires (Lysholm knee scale and SF-36) were completed. Magnetic resonance imaging/image (MRI) of the affected knee was obtained at 12 months. Ten patients in each group were required for a power analysis for the anticipated larger randomized control trial, but enrollment in each arm was not limited because of known problems with patient follow-up over a 12-month period. A total of 41 patients/fractures were enrolled in this study. Of those, only 25 patients/fractures (14 IP, 11 SP) fully complied with and completed 12 months of follow-up. Six of 11 SP presented with articular changes (chondromalacia) in the PF joint during the preinsertion arthroscopy. Three patients displayed a change in the articular cartilage based on postnail insertion arthroscopy. At 12 months, all fractures in both groups had proceeded to union. There were no differences between the affected and unaffected knee with respect to range of motion. Functional visual analog score and Lysholm knee scores showed no significant differences between groups (P > 0.05). The SF-36v2 comparison also revealed no significant differences in the overall score, all 4 mental components, and 3/4 physical components (P > 0.05). The bodily pain component score was superior in the SP group

  2. Tibial tunnel aperture location during single-bundle posterior cruciate ligament reconstruction: comparison of tibial guide positions.

    PubMed

    Shin, Young-Soo; Han, Seung-Beom; Hwang, Yeok-Ku; Suh, Dong-Won; Lee, Dae-Hee

    2015-05-01

    We aimed to compare posterior cruciate ligament (PCL) tibial tunnel location after tibial guide insertion medial (between the PCL remnant and the medial femoral condyle) and lateral (between the PCL remnant and the anterior cruciate ligament) to the PCL stump as determined by in vivo 3-dimensional computed tomography (3D-CT). Tibial tunnel aperture location was analyzed by immediate postoperative in vivo CT in 66 patients who underwent single-bundle PCL reconstruction, 31 by over-the-PCL and 35 by under-the-PCL tibial guide insertion techniques. Tibial tunnel positions were measured in the medial to lateral and proximal to distal directions of the posterior proximal tibia. The center of the tibial tunnel aperture was located more laterally (by 2.7 mm) in the over-the-PCL group than in the under-the-PCL group (P = .040) and by a relative percentage (absolute value/tibial width) of 3.2% (P = .031). Tibial tunnel positions in the proximal to distal direction, determined by absolute value and relative percentage, were similar in the 2 groups. Tibial tunnel apertures were located more laterally after lateral-to-the-PCL tibial guide insertion than after medial-to-the-PCL tibial guide insertion. There was, however, no significant difference between these techniques in distance from the joint line to the tibial tunnel aperture. Insertion lateral to the PCL stump may result in better placement of the PCL in its anatomic footprint. Level III, retrospective comparative study. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  3. Evaluating the suitability of highly cross-linked and remelted materials for use in posterior stabilized knees.

    PubMed

    Huot, J Caitlin; Van Citters, Douglas W; Currier, John H; Currier, Barbara H; Mayor, Michael B; Collier, John P

    2010-11-01

    Posterior stabilized (PS) knee designs are a popular choice for cruciate sacrificing knee arthroplasty procedures. The introduction of PS inserts fabricated from highly cross-linked and remelted Ultra High Molecular Weight Polyethylene (UHMWPE) has recently generated concern as these materials have been shown to possess reduced mechanical properties. This study investigated whether highly cross-linked and remelted UHMWPE material (referred to as XRP) can be expected to perform similarly to historical gamma-air polyethylene, which has suffered few reported incidences of tibial post failure. Never-implanted gamma-air PS tibial inserts shelf-aged 14 years were examined and compared to XRP materials. Evaluation of oxidation levels, impact toughness, and fatigue strength demonstrated never-implanted gamma-air PS tibial inserts to possess nonuniform mechanical properties. Despite severe oxidation along the exterior of gamma-air tibial posts, comparatively low oxidation levels at the center of the tibial posts corresponded to sufficiently high mechanical properties. XRP material (75 kGy) showed superior impact toughness over shelf aged gamma-air material; however, tibial post fatigue testing demonstrated XRP material (100 kGy) to be less resistant to fatigue failure than historical gamma-air material. Results from this study indicate that XRP materials (100 kGy) may demonstrate an inferior resistance to tibial post failure than historical polyethylene. © 2010 Wiley Periodicals, Inc.

  4. Tibial lengthening over humeral and tibial intramedullary nails in patients with sequelae of poliomyelitis: a comparative study.

    PubMed

    Chen, Daoyun; Chen, Jianmin; Jiang, Yao; Liu, Fanggang

    2011-06-01

    Leg discrepancy is common after poliomyelitis. Tibial lengthening is an effective way to solve this problem. It is believed lengthening over a tibial intramedullary nail can provide a more comfortable lengthening process than by the conventional technique. However, patients with sequelae of poliomyelitis typically have narrow intramedullary canals allowing limited space for inserting a tibial intramedullary nail and Kirschner wires. To overcome this problem, we tried using humeral nails instead of tibial nails in the lengthening procedure. In this study, we used humeral nails in 20 tibial lengthening procedures and compared the results with another group of patients who were treated with tibial lengthening over tibial intramedullary nails. The mean consolidation index, percentage of increase and external fixation index did not show significant differences between the two groups. However, less blood loss and shorter operating time were noted in the humeral nail group. More patients encountered difficulty with the inserted intramedullary nail in the tibial nail group procedure. The complications did not show a statistically significant difference between the two techniques on follow-up. In conclusion, we found the humeral nail lengthening technique was more suitable in leg discrepancy patients with sequelae of poliomyelitis.

  5. Preserving the PCL during the tibial cut in total knee arthroplasty.

    PubMed

    Cinotti, G; Sessa, P; Amato, M; Ripani, F R; Giannicola, G

    2017-08-01

    Previous studies have shown that the PCL insertion may be damaged during the tibial cut performed in total knee arthroplasty. We investigated the maximum thickness of a tibial cut that preserves the PCL insertion and to what extent the posterior slope of the tibial cut and that of the patient's tibial plateaus affect the outcome. MR images of 83 knees were analysed. The maximum thickness of a tibial cut that preserves the PCL using a posterior slope of 0°, 3°, 5° and parallel to the patient's slope of the tibial plateau, was evaluated. Correlations between the results and the degrees of the posterior slope of the patient's tibial plateaus were also investigated. The maximum thickness of a tibial cut that preserves the entire PCL insertion was, on average, 5.5, 4.7, 4.2 and 3.1 mm when a posterior slope of 0°, 3°, 5° and parallel to the patients' tibial plateaus was used, respectively. When the 25th percentile was considered, the maximum thickness of a tibial cut that preserved the PCL was 4 and 3 mm with a tibial cut of 0° and 5° of posterior slope, respectively. The maximum thickness of a tibial cut that preserved the PCL was significantly greater in patients with a sagittal slope of the tibial plateaus more than 8° than in those with a sagittal slope less than 8°. In cruciate retaining implants, the PCL insertion may be spared in the majority of patients by performing a tibial cut of 4 mm, or even less when a posterior slope of 3°-5° is used. The clinical relevance of our study is that the execution of a conservative tibial cut, followed by a second tibial resection to achieve the thickness required for the tibial component to be implanted, may be an alternative technique to spare the PCL in CR TKA. II.

  6. Wettability of nano-epoxies to UHMWPE fibers.

    PubMed

    Neema, S; Salehi-Khojin, A; Zhamu, A; Zhong, W H; Jana, S; Gan, Y X

    2006-07-01

    Ultra high molecular weight polyethylene (UHMWPE) fibers have a unique combination of outstanding mechanical, physical, and chemical properties. However, as reinforcements for manufacturing high performance composite materials, UHMWPE fibers have poor wettability with most polymers. As a result, the interfacial bonding strength between the fibers and polymer matrices is very low. Recently, developing so-called nano-matrices containing reactive graphitic nanofibers (r-GNFs) has been proposed to promote the wetting of such matrices to certain types of fiber reinforcements. In this work, the wettability of UHMWPE fibers with different epoxy matrices including a nano-epoxy, and a pure epoxy was investigated. Systematic experimental work was conducted to determine the viscosity of the epoxies, the contact angle between the epoxies and the fibers. Also obtained are the surface energy of the fibers and the epoxies. The experimental results show that the wettability of the UHMWPE fibers with the nano-epoxy is much better than that of the UHMWPE fibers with the pure epoxy.

  7. Relationship between product demand, tibial polyethylene insert shelf age, and total knee arthroplasty survival: retrospective review of total knees of one design.

    PubMed

    Urban, Joshua A; Collier, Matthew B; Engh, C Anderson; Engh, Gerard A

    2006-04-01

    Shelf aging of gamma-irradiated-in-air polyethylene tibial components has been associated with increased articular surface wear and an elevated risk for revision. Nine hundred fifty cruciate-retaining inserts of one design were implanted between 1987 and 1996 (shelf age, 1.0 +/- 1.2 years). Less frequently used inserts (smallest/largest sizes, thicker thicknesses, supplemental articular constraint) had longer shelf ages (means ranged from 1.2 to 2.6 years). Survival analysis showed that shelf age (P < .01) and gamma-sterilization in air (P = .01) elevated the risk for revision. Surgeons must remain attentive to identify the shelf-aged gamma-irradiated-in-air polyethylene tibial component while following designs from the era when this sterilization method was used. Recognition is expedited by understanding how shelf life is related to product demand and can be of aid when diagnosing the painful knee.

  8. Natural polyphenols enhance stability of crosslinked UHMWPE for joint implants.

    PubMed

    Shen, Jie; Gao, Guorong; Liu, Xincai; Fu, Jun

    2015-03-01

    Radiation-crosslinked UHMWPE has been used for joint implants since the 1990s. Postirradiation remelting enhances oxidative stability, but with some loss in strength and toughness. Vitamin E-stabilized crosslinked UHMWPE has shown improved strength and stability as compared with irradiated and remelted UHMWPE. With more active phenolic hydroxyl groups, natural polyphenols are widely used in the food and pharmaceutical industries as potent stabilizers and could be useful for oxidative stability in crosslinked UHMWPE. We asked whether UHMWPE blended with polyphenols would (1) show higher oxidation resistance after radiation crosslinking; (2) preserve the mechanical properties of UHMWPE after accelerated aging; and (3) alter the wear resistance of radiation-crosslinked UHMWPE. The polyphenols, gallic acid and dodecyl gallate, were blended with medical-grade UHMWPE followed by consolidation and electron beam irradiation at 100 kGy. Radiation-crosslinked virgin and vitamin E-blended UHMWPEs were used as reference materials. The UHMWPEs were aged at 120 °C in air with oxidation levels analyzed by infrared spectroscopy. Tensile (n = 5 per group) and impact (n = 3 per group) properties before and after aging as per ASTM F2003 were evaluated. The wear rates were examined by pin-on-disc testing (n = 3 per group). The data were reported as mean ± SDs. Statistical analysis was performed by using Student's t-test for a two-tailed distribution with unequal variance for tensile and impact data obtained with n ≥ 3. A significant difference is defined with p < 0.05. The oxidation induction time of 100 kGy UHMWPE was prolonged to 144 hours with 0.05 wt% dodecyl gallate and 192 hours with 0.05 wt% gallic acid compared with 48 hours for 0.05 wt% vitamin E-blended UHMWPE. Accelerated aging of these polyphenol-blended UHMWPEs resulted in ultimate tensile strength of 50.4 ± 1.4 MPa and impact strength of 53 ± 5 kJ/m(2) for 100 kGy-irradiated UHMWPE with 0.05 wt% dodecyl gallate

  9. Multilayer porous UHMWPE scaffolds for bone defects replacement.

    PubMed

    Maksimkin, A V; Senatov, F S; Anisimova, N Yu; Kiselevskiy, M V; Zalepugin, D Yu; Chernyshova, I V; Tilkunova, N A; Kaloshkin, S D

    2017-04-01

    Reconstruction of the structural integrity of the damaged bone tissue is an urgent problem. UHMWPE may be potentially used for the manufacture of porous implants simulating as closely as possible the porous cancellous bone tissue. But the extremely high molecular weight of the polymer does not allow using traditional methods of foaming. Porous and multilayer UHMWPE scaffolds with nonporous bulk layer and porous layer that mimics cancellous bone architecture were obtained by solid-state mixing, thermopressing and washing in subcritical water. Structural and mechanical properties of the samples were studied. Porous UHMWPE samples were also studied in vitro and in vivo. The pores of UHMWPE scaffold are open and interconnected. Volume porosity of the obtained samples was 79±2%; the pore size range was 80-700μm. Strong connection of the two layers in multilayer UHMWPE scaffolds was observed with decreased number of fusion defects. Functionality of implants based on multilayer UHMWPE scaffolds is provided by the fixation of scaffolds in the bone defect through ingrowths of the connective tissue into the pores, which ensures the maintenance of the animals' mobility. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Characterization of irradiated blends of alpha-tocopherol and UHMWPE.

    PubMed

    Oral, Ebru; Greenbaum, Evan S; Malhi, Arnaz S; Harris, William H; Muratoglu, Orhun K

    2005-11-01

    Adhesive/abrasive wear in ultra-high molecular weight polyethylene (UHMWPE) has been minimized by radiation cross-linking. Irradiation is followed by melting to eliminate residual free radicals and avoid long-term oxidative embrittlement. However, post-irradiation melting reduces the crystallinity of the polymer and hence its strength and fatigue resistance. We proposed an alternative to post-irradiation melting to be the incorporation of the antioxidant alpha-tocopherol into UHMWPE prior to consolidation. alpha-Tocopherol is known to react with oxygen and oxidized lipids, stabilizing them against further oxidative degradation reactions. We blended GUR 1050 UHMWPE resin powder with alpha-tocopherol at 0.1 and 0.3 wt% and consolidated these blends. Then we gamma-irradiated these blends to 100-kGy. We characterized the effect of alpha-tocopherol on the cross-linking efficiency, oxidative stability, wear behavior and mechanical properties of the blends. (I) The cross-link density of virgin, 0.1 and 0.3 wt% alpha-tocopherol blended, 100-kGy irradiated UHMWPEs were 175+/-19, 146+/-4 and 93+/-4 mol/m3, respectively. (II) Maximum oxidation indices for 100-kGy irradiated UHMWPE previously blended with 0, 0.1 and 0.3 wt% alpha-tocopherol that were subjected to accelerated aging at 80 degrees C in air for 5 weeks were 3.32, 0.09, and 0.05, respectively. (III) The pin-on-disc wear rates of 100-kGy irradiated UHMWPE previously blended with 0.1 and 0.3 wt% alpha-tocopherol that were subjected to accelerated aging at 80 degrees C in air for 5 weeks were 2.10+/-0.17 and 5.01+/-0.76 mg/million cycles, respectively. (IV) Both accelerated aged, alpha-tocopherol-blended 100-kGy irradiated UHMWPEs showed higher ultimate tensile strength, higher yield strength, and lower elastic modulus when compared to 100-kGy irradiated, virgin UHMWPE. These results showed that alpha-tocopherol-blended 100-kGy irradiated UHMWPEs were not cross-linked to the same extent as the 100-kGy irradiated

  11. In vivo degradation in modern orthopaedic UHMWPE bearings and structural characterization of a novel alternative UHMWPE material

    NASA Astrophysics Data System (ADS)

    Reinitz, Steven D.

    Ultra-high molecular weight polyethylene (UHMWPE) remains the most common bearing material for total joint arthroplasty. Advances in radiation cross-linking and other post-consolidation treatments have led to a rapid differentiation of polyethylene products on the market, with more than twenty unique materials currently being sold by the five largest orthopaedic manufacturers alone. Through oxidation, cross-link density, and free radical measurements, this work demonstrates for the first time that in vivo material degradation is occurring in cross-linked UHMWPE materials. Based on the rate of the reaction in certain materials, it is concluded that oxidative degradation may compromise the mechanical properties of the bearings in as few as ten years, potentially leading to early clinical failure of the devices. Using the knowledge gained from this work as well as previously published observations about UHMWPE oxidation, a two-mechanism model of oxidation is proposed that offers an explanation for the observed in vivo changes. From this model it is concluded that oxidative degradation is in part the result of in vivo chemical species. The two-mechanism model of oxidation suggests that different processing techniques for UHMWPE may reduce the risk of oxidative degradation. It is concluded that by avoiding any radiation cross-linking step, Equal Channel Angular Processing (ECAP) can produce UHMWPE materials with a reduced risk for in vivo oxidation while at the same time offering superior mechanical properties compared to commercially available UHMWPE materials, as well as similar wear behavior. Using dynamic mechanical analysis, the entanglement density in ECAP materials is quantified, and is related back to the ECAP processing parameters. The relationship between entanglement density and resultant material properties is established. The results will allow informed processing parameter selection for producing optimized materials for orthopaedics and other applications.

  12. [Excision of accessory navicular with reconstruction of posterior tibial tendon insertion on navicular for treatment of flatfoot related with accessory navicular].

    PubMed

    Cao, Honghui; Tang, Kanglai; Deng, Yinshuan; Tan, Xiaokang; Zhou, Binghua; Tao, Xu; Chen, Lei; Chen, Qianbo

    2012-06-01

    To analyze the excision of accessory navicular with reconstruction of posterior tibial tendon insertion on navicular for the treatment of flatfoot related with accessory navicular and to evaluate its effectiveness. Between May 2006 and June 2011, 33 patients (40 feet) with flatfoot related with accessory navicular were treated. There were 14 males (17 feet) and 19 females (23 feet) with an average age of 30.1 years (range, 16-56 years). All patients had bilateral accessory navicular; 26 had unilateral flatfoot and 7 had bilateral flatfeet. The disease duration ranged from 7 months to 9 years (median, 24 months). The American Orthopaedic Foot and Ankle Society (AOFAS) ankle-midfoot score was 47.9 +/- 7.3. The X-ray films showed type II accessory navicular, the arch height loss, and heel valgus in all patients. All of them received excision of accessory navicular and reconstruction of posterior tibial tendon insertion on navicular with anchor. All patients got primary wound healing without any complication. Thirty patients (36 feet) were followed up 6-54 months with an average of 23 months. All patients achieved complete pain relief at 6 months after surgery and had good appearance of the feet. The AOFAS ankle-midfoot score was 90.4 +/- 2.0 at last follow-up, showing significant difference when compared with preoperative score (t=29.73, P=0.00). X-ray films showed that no screw loosening or breakage was observed. There were significant differences in the arch height, calcaneus inclination angle, talocalcaneal angle, and talar-first metatarsal angle between pre-operation and last follow-up (P < 0.01). The excision of accessory navicular with reconstruction of posterior tibial tendon insertion on navicular is a good choice for the treatment of flatfoot related with accessory navicular, with correction of deformity, excellent effectiveness, and less complications.

  13. Opening the medial tibiofemoral compartment by pie-crusting the superficial medial collateral ligament at its tibial insertion: a cadaver study.

    PubMed

    Roussignol, X; Gauthe, R; Rahali, S; Mandereau, C; Courage, O; Duparc, F

    2015-09-01

    Arthroscopic treatment of tears in the middle and posterior parts of the medial meniscus can be difficult when the medial tibiofemoral compartment is tight. Passage of the instruments may damage the cartilage. The primary objective of this cadaver study was to perform an arthroscopic evaluation of medial tibiofemoral compartment opening after pie-crusting release (PCR) of the superficial medial collateral ligament (sMCL) at its distal insertion on the tibia. The secondary objective was to describe the anatomic relationships at the site of PCR (saphenous nerve, medial saphenous vein). We studied 10 cadaver knees with no history of invasive procedures. The femur was held in a vise with the knee flexed at 45°, and the medial aspect of the knee was dissected. PCR of the sMCL was performed under arthroscopic vision, in the anteroposterior direction, at the distal tibial insertion of the sMCL, along the lower edge of the tibial insertion of the semi-tendinosus tendon. Continuous 300-N valgus stress was applied to the ankle. Opening of the medial tibiofemoral compartment was measured arthroscopically using graduated palpation hooks after sequential PCR of the sMCL. The compartment opened by 1mm after release of the anterior third, 2.3mm after release of the anterior two-thirds, and 3.9mm after subtotal release. A femoral fracture occurred in 1 case, after completion of all measurements. Both the saphenous nerve and the medial saphenous vein were located at a distance from the PCR site in all 10 knees. PCR of the sMCL is chiefly described as a ligament-balancing method during total knee arthroplasty. This procedure is usually performed at the joint line, where it opens the compartment by 4-6mm at the most, with some degree of unpredictability. PCR of the sMCL at its distal tibial insertion provides gradual opening of the compartment, to a maximum value similar to that obtained with PCR at the joint space. The lower edge of the semi-tendinosus tendon is a valuable landmark

  14. Accelerated aging studies of UHMWPE. II. Virgin UHMWPE is not immune to oxidative degradation.

    PubMed

    Edidin, A A; Villarraga, M L; Herr, M P; Muth, J; Yau, S S; Kurtz, S M

    2002-08-01

    In Part I of this series, we showed that aging at elevated oxygen pressure is more successful at increasing the depth to which degradation occurs although it, too, generally causes greater degradation at the surface than at the subsurface. Therefore we hypothesized that thermal degradation alone, in the absence of free radicals, could be sufficient to artificially age UHMWPE in a manner analogous to natural aging. In the present study, virgin and air-irradiated UHMWPE (extruded GUR 1050 and compression-molded 1900) were aged up to 4 weeks at elevated oxygen pressure, and the mechanical behavior at the surface and subsurface was examined. All the materials were substantially degraded following 4 weeks of aging, but the spatial variations in the nonirradiated materials more closely mimicked the previously observed subsurface peak of degradation seen in naturally aged UHMWPE following irradiation in air. This aged material could provide a more realistic model for subsurface mechanical degradation, making it suitable for further mechanical testing in venues such as wear simulation. Copyright 2002 Wiley Periodicals, Inc.

  15. Unicompartmental knee prostheses: in vitro wear assessment of the menisci tibial insert after two different fixation methods

    NASA Astrophysics Data System (ADS)

    Affatato, S.; Spinelli, M.; Zavalloni, M.; Carmignato, S.; Lopomo, N.; Marcacci, M.; Viceconti, M.

    2008-10-01

    Knee osteoarthritis is a complex clinical scenario where many biological and mechanical factors influence the severity of articular degenerative changes. Minimally invasive knee prosthetic surgery, with only a compartment replacement (unicompartmental knee replacement), might be a good compromise between osteotomy and total knee prosthesis. The focus of this study was to develop and validate a protocol to assess the fixation method of the femoral components in mechanical simulation, for pre-clinical validation; the wear behaviour of two different fixation frames was quantified and compared. In particular, two different wear tests were conducted using the same knee simulator, the same load profiles and the same kinematics; two different fixation methods were applied to the femoral sleds (synthetic femur and metal block). Surface characterization on both articulating bearings was performed by a roughness measuring machine and coordinate measuring machine. The wear produced by the tibial inserts using the synthetic femur was considerably higher than the wear registered by the metal-block holder. Roughness measurements on femoral sleds showed a limited number of scratches with high Rt values for the metal-block set-up; the damaged surface broadened in the case of femoral condyles and tibial inserts mounted on composite bone, but lower Rt and linear penetration values were measured. The two holding frames showed different wear activities as a consequence of dissimilar dynamic performance. Further observations should be made in vivo to prove the actual importance of synthetic bone simulations and specific material behaviour.

  16. Macrophage Response to UHMWPE Submitted to Accelerated Ageing in Hydrogen Peroxide

    PubMed Central

    Rocha, Magda F.G.; Mansur, Alexandra A.P.; Martins, Camila P.S.; Barbosa-Stancioli, Edel F.; Mansur, Herman S.

    2010-01-01

    Ultra-high molecular weight polyethylene (UHMWPE) has been the most commonly used bearing material in total joint arthroplasty. Wear and oxidation fatigue resistance of UHMWPE are regarded as two important properties to extend the longevity of knee prostheses. The present study investigated the accelerated ageing of UHMWPE in hydrogen peroxide highly oxidative chemical environment. The sliced samples of UHMWPE were oxidized in a hydrogen peroxide solution for 120 days with their total level of oxidation (Iox) characterized by Fourier Transformed Infrared Spectroscopy (FTIR). The potential inflammatory response, cell viability and biocompatibility of such oxidized UHMWPE systems were assessed by a novel biological in vitro assay based on the secretion of nitric oxide (NO) by activated murine macrophages with gamma interferon (IFN-γ) cytokine and lipopolysaccharide (LPS). Furthermore, macrophage morphologies in contact with UHMWPE oxidized surfaces were analyzed by cell spreading-adhesion procedure using scanning electron microscopy (SEM). The results have given significant evidence that the longer the period of accelerated aging of UHMWPE the higher was the macrophage inflammatory equivalent response based on NO secretion analysis. PMID:20721321

  17. Effect of shoe insert construction on foot and leg movement.

    PubMed

    Nigg, B M; Khan, A; Fisher, V; Stefanyshyn, D

    1998-04-01

    The purpose of this study was to quantify changes in foot eversion and tibial rotation during running resulting from systematic changes of material composition of five shoe inserts of the same shape. Tests were performed with 12 subjects. The inserts had a bilayer design using two different materials at the top and bottom of the insert. The functional kinematic variables examined in this study were the foot-leg in-eversion angle, beta, and the leg-foot tibial rotation, rho. Additionally, the subject characteristics of arch height, relative arch deformation, and active range of motion were quantified. The statistical analysis used was a two way repeated measures MANOVA (within trials and inserts). The average group changes resulting from the studied inserts in total shoe eversion, total foot eversion, and total internal tibial rotation were typically smaller than 1 degree when compared with the no-insert condition and were statistically not significant. The measured ranges of total foot eversion for all subjects were smallest for the softest and about twice as large for the hardest insert construction. Thus, the soft insert construction was more restrictive, forcing all feet into a similar movement pattern, whereas the harder combinations allowed for more individual variation of foot and leg movement and did not force the foot into a preset movement pattern. The individual results showed substantial differences between subjects and a trend: Subjects who generally showed a reduction of tibial rotation with all tested inserts typically had a flexible foot. However, subjects who generally showed an increase of tibial rotation typically had a stiff foot. The results of this study suggest that subject specific factors such as static, dynamic, and neuro-physiological characteristics of foot and leg are important to match specific feet and shoe inserts optimally.

  18. Does a conservative tibial cut in conventional total knee arthroplasty violate the deep medial collateral ligament?

    PubMed

    Maes, Michael; Luyckx, Thomas; Bellemans, Johan

    2014-11-01

    Based on the anatomy of the deep medial collateral ligament (MCL), it was hypothesized that at least part of its cross-sectional insertion area is jeopardized while performing a standard tibial cut in conventional total knee arthroplasty (TKA). The aim of this study was to determine whether it is anatomically possible to preserve the tibial deep MCL insertion during conventional TKA. Thirty-three unpaired cadaveric knee specimens were used for this study. Knees with severe varus/valgus deformity or damage to the medial structures of the knee were excluded. In the first part of the study, the dimensions of the tibial insertion of the deep MCL and its relationship to the joint line were recorded. Next, the cross-sectional area of the deep MCL insertion was determined using calibrated digital photographic analysis. In the second part, the effect of a standard 9-mm 3° sloped tibial cut on the structural integrity of the deep MCL cross-sectional insertion area was determined using conventional instrumentation. The proximal border of the deep MCL insertion site on the tibia was located on average 4.7 ± 1.2 mm distally to the joint line. After performing a standard 9-mm 3° sloped tibial cut, on average 54% of the deep MCL insertion area was resected. In 29% of the cases, the deep MCL insertion area was completely excised. The deep MCL cannot routinely be preserved in conventional TKA. The deep MCL insertion is at risk and may be jeopardized in case of a tibial cut 9 mm below the native joint line. As the deep MCL is a distinct medial stabilizer and plays an important role in rotational stability, this may have implications in future designs of both unicondylar and total knee arthroplasty, but further research is necessary.

  19. Characterization and Accelerated Ageing of UHMWPE Used in Orthopedic Prosthesis by Peroxide

    PubMed Central

    Rocha, Magda; Mansur, Alexandra; Mansur, Herman

    2009-01-01

    Ultra-high molecular weight polyethylene (UHMWPE) has been the most commonly used bearing material in total joint arthroplasty. Wear and oxidation fatigue resistance of UHMWPE are regarded as two important mechanical properties to extend the longevity of knee prostheses. Though accelerated in vitro protocols have been developed to test the relative oxidation resistance of various types of UHMWPE, its mechanism is not accurately understood yet. Thus, in the present study an accelerated ageing of UHMWPE in hydrogen peroxide solution was performed and relative oxidation was extensively characterized by Fourier Transformed Infrared Spectroscopy (FTIR) spectroscopy and the morphological changes were analyzed by Scanning Electron Microscopy (SEM). Different chemical groups of UHMWPE associated with the degradation reaction were monitored for over 120 days in order to evaluate the possible oxidation mechanism(s) which may have occurred. The results have provided strong evidence that the oxidation mechanism is rather complex, and two stages with their own particular first-order kinetics reaction patterns have been clearly identified. Furthermore, hydrogen peroxide has proven to be an efficient oxidative medium to accelerate ageing of UHMWPE.

  20. Novel active stabilization technology in highly crosslinked UHMWPEs for superior stability

    NASA Astrophysics Data System (ADS)

    Oral, Ebru; Neils, Andrew L.; Wannomae, Keith K.; Muratoglu, Orhun K.

    2014-12-01

    Radiation cross-linked ultrahigh molecular weight polyethylene (UHMWPE) is the bearing of choice in joint arthroplasty. The demands on the longevity of this polymer are likely to increase with the recently advancing deterioration of the performance of alternative metal-on-metal implants. Vitamin E-stabilized, cross-linked UHMWPEs are considered the next generation of improved UHMWPE bearing surfaces for improving the oxidation resistance of the polymer. It was recently discovered that in the absence of radiation-induced free radicals, lipids absorbed into UHMWPE from the synovial fluid can initiate oxidation and result in new free radical-mediated oxidation mechanisms. In the presence of radiation-induced free radicals, it is possible for the polymer to oxidize through both existing free radicals at the time of implantation and through newly formed free radicals in vivo. Thus, we showed that reducing the radiation-induced free radicals in vitamin E-stabilized UHMWPE would increase its oxidative stability and presumably lead to improved longevity. We describe mechanical annealing and warm irradiation of irradiated vitamin E blends as novel methods to eliminate 99% of radiation-induced free radicals without sacrificing crystallinity. These are significant improvements in the processing of highly cross-linked UHMWPE for joint implants with improved longevity.

  1. Peak Stress Intensity Factor Governs Crack Propagation Velocity In Crosslinked UHMWPE

    PubMed Central

    Sirimamilla, P. Abhiram; Furmanski, Jevan; Rimnac, Clare

    2013-01-01

    Ultra high molecular weight polyethylene (UHMWPE) has been successfully used as a bearing material in total joint replacement components. However, these bearing materials can fail as a result of in vivo static and cyclic loads. Crack propagation behavior in this material has been considered using the Paris relationship which relates fatigue crack growth rate, da/dN (mm/cycle) versus the stress intensity factor range, ΔK (Kmax-Kmin, MPa√m). However, recent work suggests that the crack propagation velocity of conventional UHMWPE is driven by the peak stress intensity (Kmax), not ΔK. The hypothesis of this study is that the crack propagation velocity of highly crosslinked and remelted UHMWPE is also driven by the peak stress intensity, Kmax, during cyclic loading, rather than by ΔK. To test this hypothesis, two highly crosslinked (65 kGy and 100 kGy) and remelted UHMWPE materials were examined. Frequency, waveform and R-ratio were varied between test conditions to determine the governing factor for fatigue crack propagation. It was found that the crack propagation velocity in crosslinked UHMWPE is also driven by Kmax and not ΔK, and is dependent on loading waveform and frequency in a predictable quasi-static manner. The current study supports that crack growth in crosslinked UHMWPE materials, even under cyclic loading conditions, can be described by a relationship between the velocity of crack growth, da/dt and the peak stress intensity, Kmax. The findings suggest that stable crack propagation can occur as a result of static loading only and this should be taken into consideration in design of UHMWPE total joint replacement components. PMID:23165898

  2. Influence of heat treatment on structural, mechanical and wear properties of crosslinked UHMWPE.

    PubMed

    Chiesa, R; Moscatelli, M; Giordano, C; Siccardi, F; Cigada, A

    2004-01-01

    New crosslinked ultra high molecular weight polyethylenes (UHMWPEs) have recently been developed, characterized and introduced in clinical applications. UHMWPE cross-linking treatments are very promising for reducing osteolysis induced by wear debris. The irradiation type, gamma or beta, the dosage and the thermal treatment performed during or following the irradiation process are all factors affecting polyethylene wear resistance. Thermal stabilization treatments performed after or during the irradiation process at a temperature above melting point (i.e. >130 degrees C) have been proven to effectively remove the free radicals generated during irradiation from UHMWPE, but their effect on the mechanical properties of UHMWPE are not completely clear. In addition to wear rate reduction, maintaining good mechanical properties is fundamental aspect in designing the new generation of crosslinked UHMWPE for artificial load bearing materials, especially considering the application in total knee replacements. In this study, we investigated the influence of different stabilization treatments, performed after gamma irradiation, on structural, wear and mechanical properties of UHMWPE. We performed four different stabilization treatments, with different temperatures and cooling rates, on 100 kGy gamma irradiated UHMWPE. Structural properties of UHMWPE were assessed by differential scanning calorimetry (DSC). To assess the mechanical performance of the materials, uni-axial tensile tests were performed according to the ASTM D638 standard, bi-axial tension performance was evaluated by small punch tests (ASTM F2183-02), toughness resistance was evaluated by the Izod method (ASTM F648), and cold flow resistance was analysed by a dynamic compressive test. Evaluation of wear resistance was by a multidirectional pin-on-disk screening machine. Materials considered were in "aged" and "non-aged" conditions. Results confirmed that cross-linking greatly enhances UHMWPE wear resistance, but

  3. SPECT/CT tracer uptake is influenced by tunnel orientation and position of the femoral and tibial ACL graft insertion site.

    PubMed

    Hirschmann, Michael T; Mathis, Dominic; Rasch, Helmut; Amsler, Felix; Friederich, Niklaus F; Arnold, Markus P

    2013-02-01

    graft. A more horizontal femoral graft position showed significantly increased tracer uptake within the superior and posterior femoral regions. A more posteriorly-placed femoral insertion site showed significantly more tracer uptake within the femoral and tibial tunnel regions. A more vertical or a less medial tibial tunnel orientation showed significant increased uptake within the tibial and femoral tunnel regions. A more anterior tibial tunnel position showed significantly more tracer uptake in the femoral and tibial tunnel regions as well as the entire tibiofemoral joint. SPECT/CT tracer uptake intensity and distribution showed a significant correlation with the femoral and tibial tunnel position and orientation in patients with symptomatic knees after ACL reconstruction. No correlation was found with stability or clinical laxity. SPECT/CT tracer uptake distribution has the potential to give us important information on joint homeostasis and remodelling after ACL reconstruction. It might help to predict ACL graft failure and improve our surgical ACL reconstruction technique in finding the optimal tunnel and graft position and orientation.

  4. Anterior Cruciate Ligament Reconstruction with Tibial Attachment Preserving Hamstring Graft without Implant on Tibial Side

    PubMed Central

    Sinha, Skand; Naik, Ananta Kumar; Maheshwari, Mridul; Sandanshiv, Sumedh; Meena, Durgashankar; Arya, Rajendra K

    2018-01-01

    Background: Tibial attachment preserving hamstring graft could prevent potential problems of free graft in anterior cruciate ligament (ACL) reconstruction such as pull out before graft-tunnel healing or rupture before ligamentization. Different implants have been reportedly used for tibial side fixation with this technique. We investigated short-term outcome of ACL reconstruction (ACLR) with tibial attachment sparing hamstring graft without implant on the tibial side by outside in technique. Materials and Methods: Seventy nine consecutive cases of ACL tear having age of 25.7 ± 6.8 years were included after Institutional Board Approval. All subjects were male. The mean time interval from injury to surgery was of 7.5 ± 6.4 months. Hamstring tendons were harvested with open tendon stripper leaving the tibial insertion intact. The free ends of the tendons were whip stitched, quadrupled, and whip stitched again over the insertion site of hamstring with fiber wire (Arthrex). Single bundle ACLR was done by outside in technique and the femoral tunnel was created with cannulated reamer. The graft was pulled up to the external aperture of femoral tunnel and fixed with interference screw (Arthrex). The scoring was done by Lysholm, Tegner, and KT 1000 by independent observers. All cases were followed up for 2 years. Results: The mean length of quadrupled graft attached to tibia was 127.65 ± 7.5 mm, and the mean width was 7.52 ± 0.78 mm. The mean preoperative Lysholm score of 47.15 ± 9.6, improved to 96.8 ± 2.4 at 1 year. All cases except two returned to the previous level of activity after ACLR. There was no significant difference statistically between preinjury (5.89 ± 0.68) and postoperative (5.87 ± 0.67) Tegner score. The anterior tibial translation (ATT) (KT 1000) improved from 11.44 ± 1.93 mm to 3.59 ± 0.89 mm. The ATT of operated knee returned to nearly the similar value as of the opposite knee (3.47 ± 1.16 mm). The Pivot shift test was negative in all cases

  5. Thermal Response of UHMWPE Materials in a Flash Flame Test Environment

    DTIC Science & Technology

    2014-11-13

    Evaluation of Flame Resistant Clothing for Protection Against Fire Simulations Using an Instrumented Manikin. Several UHMWPE fabrics were tested underneath...PROTECTIVE CLOTHING COTTON FLASH FLAMES UNDERGARMENTS TEST AND EVALUATION FABRICS FLAME TESTING FIRE ...PROTECTION FIRE RESISTANT TEXTILES UHMWPE(ULTRA HIGH MOLECULAR WEIGHT POLYETHYLENE

  6. The effect of accelerated aging on the wear of UHMWPE.

    PubMed

    Sakoda, H; Fisher, J; Lu, S; Buchanan, F

    2001-01-01

    Oxidative degradation of UHMWPE has been found to be a cause of elevated wear rate of the polymer in total joint replacement leading to failure of these devices. In order to evaluate long term stability of polymers, various accelerated aging methods have been developed. In this study, wear rates of shelf aged UHMWPE and "accelerated aged" UHMWPE were compared using a multi-directional pin-on-plate wear test machine in order to evaluate the effect of the accelerated aging on wear. Wear factors of the aged materials were found to depend on their density, which is a measure of oxidation level. Finally, accelerated aging was calibrated against shelf aging in terms of wear rate. Copyright 2001 Kluwer Academic Publishers

  7. Ceramic hemi-unicondylar arthroplasty in an adolescent patient with idiopathic tibial chondrolysis.

    PubMed

    Dombroski, Derek; Garino, Jonathan; Lee, Gwo-Chin

    2009-06-01

    Despite recent advances in cartilage regeneration and restoration procedures, isolated, large, full-thickness cartilage lesions in young patients continue to pose significant challenges to patients and orthopedic surgeons. Treatment options for this difficult problem have traditionally included arthrodesis, osteotomy, osteochondral allograft, and prosthetic reconstruction. We present a case of an adolescent patient with isolated idiopathic lateral tibial chondrolysis treated with a custom ceramic hemi-unicondylar hemiarthroplasty. Preoperatively, a 3-dimensional computed tomography scan of the patient's knee was obtained to begin manufacturing a conforming custom ceramic insert that would articulate between the tibial base plate and the patient's native lateral femoral cartilage. Through a lateral parapatellar approach, the tibial preparation was carried out using the Zimmer M/G unicompartmental knee system (Warsaw, Indiana), and the tibial base plate was cemented into position in the standard fashion. A custom, conforming, prefabricated ceramic insert (CeramTec, Memphis, Tennessee) was then inserted onto the tibial base plate. At 5-year follow-up, this salvage procedure was successful in relieving pain and restoring function in this young patient. There were no signs of implant loosening or lysis. Magnetic resonance imaging of the knee at last follow-up revealed that the cartilage thickness of the patient's lateral femoral condyle remained unchanged. Unicondylar hemiarthroplasty performed in patients with large unipolar lesions in the knee can provide durable and reliable pain relief. Ceramic is a viable material that can be considered for articulation with native cartilage.

  8. The risk of sacrificing the PCL in cruciate retaining total knee arthroplasty and the relationship to the sagittal inclination of the tibial plateau.

    PubMed

    Sessa, Pasquale; Fioravanti, Giulio; Giannicola, Giuseppe; Cinotti, Gianluca

    2015-01-01

    In cruciate retaining total knee arthroplasty (TKA), a partial avulsion of PCL may occur when en-bloc tibial osteotomy is performed. We evaluated the effects of a tibial cut performed with different degrees of posterior slope on PCL insertion and whether the results are affected by the sagittal inclination of the patient's tibial plateau. We selected 83 MRIs of knees showing mild or no degenerative changes. The effects of a simulated tibial cut performed with a posterior slope of 0°, 3°, 5° and parallel to the patient's tibial plateau inclination on PCL insertion in the proximal tibia were investigated. The results were correlated with the degree of posterior inclination of the tibial plateau. Every angle we used for the tibial cut caused a PCL avulsion greater than 50%. The percentage of PCL avulsion significantly increased with increasing the posterior slope of the tibial cut. Patients with sagittal tibial plateau inclination <5° showed greater PCL avulsion than those with sagittal inclination >8°. Most of the PCL insertion is likely to be sacrificed when resection of the proximal tibia is performed en-block. The risk of PCL avulsion is reduced in patients showing a marked posterior inclination of the tibial plateau, but even in this group of patients a surgical technique aimed at sparing most of the PCL insertion is necessary. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Texturing of UHMWPE surface via NIL for low friction and wear properties

    NASA Astrophysics Data System (ADS)

    Suryadi Kustandi, Tanu; Choo, Jian Huei; Low, Hong Yee; Sinha, Sujeet K.

    2010-01-01

    Wear is a major obstacle limiting the useful life of implanted ultra-high molecular weight polyethylene (UHMWPE) components in total joint arthroplasty. It has been a continuous effort in the implant industry to reduce the frictional wear problem of UHMWPE by improving the structure, morphology and mechanical properties of the polymer. In this paper, a new paradigm that utilizes nanoimprint lithography (NIL) in producing textures on the surface of UHMWPE is proposed to efficiently improve the tribological properties of the polymer. Friction and wear experiments were conducted on patterned and controlled (non-patterned) UHMWPE surfaces using a commercial tribometer, mounted with a silicon nitride ball, under a dry-sliding condition with normal loads ranging from 60 to 200 mN. It has been shown that the patterned UHMWPE surface showed a reduction in the coefficient of friction between 8% and 35% as compared with the controlled (non-patterned) surface, depending on the magnitude of the normal load. Reciprocating wear experiments also showed that the presence of surface textures on the polymer resulted in lower wear depth and width, with minimal material transfer to the sliding surface.

  10. ACL double-bundle reconstruction with one tibial tunnel provides equal stability compared to two tibial tunnels.

    PubMed

    Drews, Björn Holger; Seitz, Andreas Martin; Huth, Jochen; Bauer, Gerhard; Ignatius, Anita; Dürselen, Lutz

    2017-05-01

    . With regard to individualized ACL reconstruction, the double-bundle technique with one tibial tunnel offers a possibility to address small tibial insertion sites without compromising the advantages of a double-bundle procedure.

  11. Development of Ultra-High Molecular Weight Polyethylene (UHMWPE) Coating by Cold Spray Technique

    NASA Astrophysics Data System (ADS)

    Ravi, Kesavan; Ichikawa, Yuji; Deplancke, Tiana; Ogawa, Kazuhiro; Lame, Olivier; Cavaille, Jean-Yves

    2015-08-01

    Ultra-high molecular weight polyethylene or UHMWPE is an extremely difficult material to coat with, as it is rubbery and chemically very inert. The Cold Spray process appears to be a promising alternative processing technique but polymers are in general difficult to deposit using this method. So, attempts to develop UHMWPE coatings were made using a downstream injection cold spray technique incorporating a few modifications. A conventional cold spray machine yielded only a few deposited particles of UHMWPE on the substrate surface, but with some modifications in the nozzle geometry (especially the length and inner geometry) a thin coating of 45 μm on Al substrate was obtained. Moreover, experiments with the addition of fumed nano-alumina to the feedstock yielded a coating of 1-4 mm thickness on Al and polypropylene substrates. UHMWPE was seen to be melt crystallized during the coating formation, as can be seen from the differential calorimetry curves. Influence of nano-ceramic particles was explained by observing the creation of a bridge bond between UHMWPE particles.

  12. J-integral fracture toughness and tearing modulus measurement of radiation cross-linked UHMWPE.

    PubMed

    Gomoll, A; Wanich, T; Bellare, A

    2002-11-01

    Radiation and chemical cross-linking of medical grade ultrahigh molecular weight polyethylene (UHMWPE) has recently been utilized in an effort to improve wear performance of total joint replacement components. However, reductions in mechanical properties with cross-linking are cause for concern regarding the use of cross-linked UHMWPE for high-stress applications such as in total knee replacement prostheses. In this study, the fracture behavior of radiation cross-linked UHMWPE was compared to that of uncross-linked UHMWPE. The Rice and Sorensen model that utilizes mechanical parameters obtained from uniaxial tensile and compact tension tests was used to calculate the steady state J-integral fracture toughness, Jss, for radiation cross-linked UHMWPE. Jss decreased monotonically with increase in radiation dose. UHMWPE exhibited tough, ductile tearing behavior with stable crack growth when it was cross-linked using a gamma radiation dose of 0-50 kGy. However, in cross-linked UHMWPE irradiated to a dose of 100 and 200 kGy, unstable fracture occurred spontaneously upon attaining the initial crack driving force, J1c. This indicates that a high degree of cross-linking is less desirable for high-stress applications in orthopaedic implants. However, a substantial increase in J1c, even at a low degree of cross-linking, suggests that a low degree of cross-linking may be beneficial for resistance to delamination and catastrophic failure, both of which require an initiation step for the fracture to propagate in the material. This mechanical test should, however, be considered along with fatigue tests and joint simulator testing before determination of an appropriate amount of cross-linking for total joint replacement prostheses that experience high stresses.

  13. An Improved Tibial Force Sensor to Compute Contact Forces and Contact Locations In Vitro After Total Knee Arthroplasty.

    PubMed

    Roth, Joshua D; Howell, Stephen M; Hull, Maury L

    2017-04-01

    Contact force imbalance and contact kinematics (i.e., motion of the contact location in each compartment during flexion) of the tibiofemoral joint are both important predictors of a patient's outcome following total knee arthroplasty (TKA). Previous tibial force sensors have limitations in that they either did not determine contact forces and contact locations independently in the medial and lateral compartments or only did so within restricted areas of the tibial insert, which prevented them from thoroughly evaluating contact force imbalance and contact kinematics in vitro. Accordingly, the primary objective of this study was to present the design and verification of an improved tibial force sensor which overcomes these limitations. The improved tibial force sensor consists of a modified tibial baseplate which houses independent medial and lateral arrays of three custom tension-compression transducers each. This sensor is interchangeable with a standard tibial component because it accommodates tibial articular surface inserts with a range of sizes and thicknesses. This sensor was verified by applying known loads at known locations over the entire surface of the tibial insert to determine the errors in the computed contact force and contact location in each compartment. The root-mean-square errors (RMSEs) in contact force are ≤ 6.1 N which is 1.4% of the 450 N full-scale output. The RMSEs in contact location are ≤ 1.6 mm. This improved tibial force sensor overcomes the limitations of the previous sensors and therefore should be useful for in vitro evaluation of new alignment goals, new surgical techniques, and new component designs in TKA.

  14. Surgical treatment of avulsion fractures at the tibial insertion of the posterior cruciate ligament: functional result☆

    PubMed Central

    Barros, Marcos Alexandre; Cervone, Gabriel Lopes de Faria; Costa, André Luis Serigatti

    2015-01-01

    Objective To objectively and subjectively evaluate the functional result from before to after surgery among patients with a diagnosis of an isolated avulsion fracture of the posterior cruciate ligament who were treated surgically. Method Five patients were evaluated by means of reviewing the medical files, applying the Lysholm questionnaire, physical examination and radiological examination. For the statistical analysis, a significance level of 0.10 and 95% confidence interval were used. Results According to the Lysholm criteria, all the patients were classified as poor (<64 points) before the operation and evolved to a mean of 96 points six months after the operation. We observed that 100% of the posterior drawer cases became negative, taking values less than 5 mm to be negative. Conclusion Surgical methods with stable fixation for treating avulsion fractures at the tibial insertion of the posterior cruciate ligament produce acceptable functional results from the surgical and radiological points of view, with a significance level of 0.042. PMID:27218073

  15. Rupture of the anterior tibial tendon: three clinical cases, anatomical study, and literature review.

    PubMed

    Anagnostakos, Konstantinos; Bachelier, Felix; Fürst, Oliver Alexander; Kelm, Jens

    2006-05-01

    We report three cases of anterior tibial tendon ruptures and the results of an anatomical study in regard to the tendon's insertion site and a literature review. Three patients were referred to our hospital with anterior tibial tendon ruptures. In the anatomical study, 53 feet were dissected, looking in particular for variants of the bony insertion of the tendon. Two patients had surgical treatment (one primary repair and one semimembranosus tendon graft) and one conservative treatment. After a mean followup of 14 weeks all patients had satisfactory outcomes. In the anatomical study, we noted three different insertion sites: in 36 feet the tendon inserted into the medial side of the cuneiform and the base of the first metatarsal bone and in 13 feet only into the medial side of the cuneiform bone. In the remaining four feet the tendon inserted into the cuneiform and the first metatarsal bone, but an additional tendon was noted taking its origin from the anterior tibial tendon near its insertion into the medial cuneiform and attaching to the proximal part of the first metatarsal. According to literature, surgical repair is the treatment of choice for acute ruptures and for patients with high activity levels. For chronic ruptures and patients with low demands, conservative management may lead to an equally good outcome. Knowledge of the anatomy in this region may be helpful for diagnosis and for the interpretation of intraoperative findings and choosing the most appropriate surgical procedure.

  16. Comparison of mechanical and tribotechnical properties of UHMWPE reinforced with basalt fibers and particles

    NASA Astrophysics Data System (ADS)

    Panin, S. V.; Kornienko, L. A.; Alexenko, V. O.; Qitao, Huang; Ivanova, L. R.

    2016-11-01

    Mechanical and tribotechnical properties of UHMWPE composites reinforced with basalt fibers and particles under dry sliding friction and abrasion were investigated. It is shown that adding of the basalt particles provides higher wear resistance under the dry sliding friction while at abrasion filling by the basalt fibers is more efficient since the wear resistance of the reinforced UHMWPE composites is by 3.7 times higher in contrast with the neat polymer. Wear mechanisms of the polymeric UHMWPE composites under various types of wear are discussed.

  17. Kinematic comparison between mobile-bearing and fixed-bearing inserts in NexGen legacy posterior stabilized flex total knee arthroplasty.

    PubMed

    Shi, Kenrin; Hayashida, Kenji; Umeda, Naoya; Yamamoto, Kengo; Kawai, Hideo

    2008-02-01

    Femoral component rollback and tibial rotation were evaluated using lateral radiographs taken during passive knee flexion under fluoroscopy in NexGen Legacy Posterior Stabilized Flex (Zimmer, Warsaw, Ind) total knee arthroplasties (TKAs; 30 with mobile insert and 26 with fixed insert). Measured maximal flexion angle demonstrated no significant differences. Femoral component rollback was observed predominantly in TKAs with fixed insert in more than 45 degrees flexion and correlated with maximal flexion angle in each group. Tibial internal rotation was more significant in TKAs with mobile insert in maximal flexion. However, tibial internal rotation from 90 degrees to maximal flexion, which demonstrated correlation with maximal flexion angle in each group, did not show significant difference. The kinematic differences between 2 inserts seemed to have little relevance to the maximal flexion angle.

  18. The Mechanical Properties and Modeling of Creep Behavior of UHMWPE/Nano-HA Composites

    NASA Astrophysics Data System (ADS)

    Li, Fan; Gao, Lilan; Gao, Hong; Cui, Yun

    2017-09-01

    Composites with different levels of hydroxyapatite (HA) content and ultra-high molecular weight polyethylene (UHMWPE) were prepared in this work. Mechanical properties of the composites were examined here, and to evaluate the effect of HA particles on the time-dependent behavior of the pure matrix, the creep and recovery performance of composites at various stress levels were also researched. As expected, the addition of HA influenced the time-dependent response of the UHMWPE and the effect had a strong dependence on the HA content. The creep and recovery strain of the composites significantly decreased with increasing HA content, and tensile properties were also impaired, which was due to the concentration of HA fillers. The mechanism and effect of HA dispersed into the UHMWPE matrix were examined by scanning electron microscopy. Additionally, since variations in the adjusted parameters revealed the impact of HA on the creep behavior of the UHMWPE matrix, Findley's model was employed. The results indicated that the analytical model was accurate for the prediction of creep of the pure matrix and its composites.

  19. A Multidirectional Tribo-System: Wear of UHMWPE under Sliding, Rolling, and Rotation

    NASA Astrophysics Data System (ADS)

    Patten, Elias Wolfgang

    Total knee replacements (TKR) have become a successful surgical procedure for addressing end-stage osteoarthritis, with ultra-high molecular weight polyethylene and cobalt chrome alloy (UHMWPE/Co-Cr) serving as the bearing materials of choice for decades. However, more than 10% of TKRs fail and require revision surgery. The predominant challenge with UHMWPE is the particulate debris generated through wear-mediated processes; wear debris from the UHMWPE tibial bearing surface leading to loosening is still the main cause for post-fifth-year revisions. UHMWPE wear in hip arthroplasty has been linked to microstructural evolution at the surface from multidirectional sliding in the hip joint but little is known about how the microstructure responds to clinically relevant sliding conditions in the knee. This is likely because wear tests are typically performed under basic motion parameters with simplified geometry (pin-on-disk tests) while the knee has more complex kinematics: it is neither a ball-and-socket joint nor a simple hinge joint, but has 2D sliding, rolling/slip motion, and rotation. There is also disagreement over how to best quantify cross-shear and how to model how much wear it will cause. A custom multidirectional tribo-system was used to investigate the individual and combined effects of the different motions in TKR: 2D sliding, rolling, and rotation, for a total of eight separate kinematic conditions. The trends in wear rates and wear factors for these different motions were compared with many different definitions for magnitudes and ratios of cross-shear. Additionally, the wear surfaces were examined for wear mechanism and the microstructural changes in lamellae orientation for the different motions were analyzed. To mimic the tribological conditions of a condyle in a TKR, polished Co-Cr spheres were articulated against flat, smooth UHMWPE disks with physiologically relevant loading, speed, and lubrication conditions. The motion parameters were selected

  20. The effect of alpha-tocopherol on the oxidation and free radical decay in irradiated UHMWPE.

    PubMed

    Oral, Ebru; Rowell, Shannon L; Muratoglu, Orhun K

    2006-11-01

    We developed a radiation cross-linked ultra-high molecular weight polyethylene (UHMWPE) stabilized with alpha-tocopherol (Vitamin E) as a bearing material in total joint replacements. The stabilizing effect of alpha-tocopherol on free radical reactions in UHMWPE is not well understood. We investigated the effect of alpha-tocopherol on the oxidation and transformation of residual free radicals during real-time aging of alpha-tocopherol-doped, irradiated UHMWPE (alphaTPE) and irradiated UHMWPE (control). Samples were aged at 22 degrees C (room temperature) in air, at 40 degrees C in air and at 40 degrees C in water for 7 months. During the first month, alphaTPE showed some oxidation at the surface, which stayed constant thereafter. Control exhibited substantial oxidation in the subsurface region, which increased with time. The alkyl/allyl free radicals transformed to oxygen centered ones in both materials; this transformation occurred faster in alpha-TPE. In summary, the real-time oxidation behavior of alpha-TPE was consistent with that observed using accelerated aging methods. This new UHMWPE is oxidation resistant and is expected to maintain its properties in the long term.

  1. Micromechanical models for the stiffness and strength of UHMWPE macrofibrils

    NASA Astrophysics Data System (ADS)

    Dong, Hai; Wang, Zheliang; O'Connor, Thomas C.; Azoug, Aurelie; Robbins, Mark O.; Nguyen, Thao D.

    2018-07-01

    Ultrahigh molecular weight polyethylene (UHMWPE) fibers have a complex hierarchical structure that at the micron-scale is composed of oriented chain crystals, lamellar crystals, and amorphous domains organized into macrofibrils. We developed a computational micromechanical modeling study of the effects of the morphological structure and constituent material properties on the deformation mechanisms, stiffness and strength of the UHMWPE macrofibrils. Specifically, we developed four representative volume elements, which differed in the arrangement and orientation of the lamellar crystals, to describe the various macrofibrillar microstructures observed in recent experiments. The stiffness and strength of the crystals were determined from molecular dynamic simulations of a pure PE crystal. A finite deformation crystal plasticity model was used to describe the crystals and an isotropic viscoplastic model was used for the amorphous phase. The results show that yielding in UHMWPE macrofibrils under axial tension is dominated by the slip in the oriented crystals, while yielding under transverse compression and shear is dominated by slips in both the oriented and lamellar crystals. The results also show that the axial modulus and strength are mainly determined by the volume fraction of the oriented crystals and are insensitive to the arrangements of the lamellar crystals when the modulus of the amorphous phase is significantly smaller than that of the crystals. In contrast, the arrangement and size of the lamellar crystals have a significant effect on the stiffness and strength under transverse compression and shear. These findings can provide a guide for new materials and processing design to improve the properties of UHMWPE fibers by controlling the macrofibrillar morphologies.

  2. Trace concentrations of vitamin E protect radiation crosslinked UHMWPE from oxidative degradation.

    PubMed

    Kurtz, S M; Dumbleton, J; Siskey, R S; Wang, A; Manley, M

    2009-08-01

    The effect of very low concentrations of Vitamin E on the stability and mechanical behavior of UHMWPE remains unknown. We tested the hypothesis that the oxidation resistance of Vitamin E-blended UHMWPE would be influenced by trace doses of antioxidant, resin, and radiation treatment. Trace concentrations (< or =500 ppm w/w%) of alpha-tocopherol (Vitamin E) were blended separately with GUR 1020 and 1050 resins and molded into disks. From each disk, three groups of 10 mm thick blocks were machined: (1) no irradiation (control); (2) 30 kGy of gamma irradiation in nitrogen; and (3) 75 kGy of gamma irradiation in air. Specimens were subjected to three aging protocols: (a) no aging (control); (b) two weeks and (c) four weeks of accelerated aging in accordance with ASTM F 2003 (i.e., 70 degrees C and 5 atm oxygen). The minimum concentration of Vitamin E needed to stabilize UHMWPE during our accelerated tests depended upon the method of radiation processing. For the 30 and 75 kGy irradiated materials, the addition of 125 ppm or more Vitamin E was sufficient to maintain baseline mechanical and chemical properties through two weeks of accelerated aging. For these groups, the addition of 375 ppm or 500 ppm, respectively, was necessary to maintain baseline mechanical and chemical properties throughout the four-week accelerated aging period. UHMWPE resin molecular weight did not have an effect on oxidation behavior. The results of this experiment therefore supported our hypotheses that trace concentrations of Vitamin E, coupled with radiation treatment-but not resin grade-influence the mechanical and oxidative degradation behavior of UHMWPE.

  3. Radiopaque UHMWPE sublaminar cables for spinal deformity correction: Preclinical mechanical and radiopacifier leaching assessment.

    PubMed

    Roth, Alex K; Boon-Ceelen, Karlien; Smelt, Harold; van Rietbergen, Bert; Willems, Paul C; van Rhijn, Lodewijk W; Arts, Jacobus J

    2018-02-01

    Polymeric sublaminar cables have a number of advantages over metal cables in the field of spinal deformity surgery, with decreased risk of neurological injury and potential for higher correction forces as the two most predominant. However, currently available polymer cables are radiolucent, precluding postoperative radiological assessment of instrumentation stability and integrity. This study provides a preclinical assessment of a woven UHMWPE cable made with radiopaque UHMWPE fibers. Our primary goal was to determine if the addition of a radiopacifier negatively affects the mechanical properties of UHMWPE woven cables. Tensile mechanical properties were determined and compared to suitable controls. Radiopacity was evaluated and radiopacifier leaching was assessed in vitro and in vivo. Finally, in vivo bismuth organ content was quantified after a 24-week implantation period in sheep. Results show that the mechanical properties of woven UHMWPE cables were not deleteriously affected by the addition of homogenously dispersed bismuth oxide particles within each fiber. Limited amounts of bismuth oxide were released in vitro, well below the toxicological threshold. Tissue concentrations lower than generally accepted therapeutic dosages for use against gastrointestinal disorders, well below toxic levels, were discovered in vivo. These results substantiate controlled clinical introduction of these radiopaque UHMWPE cables. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 771-779, 2018. © 2017 Wiley Periodicals, Inc.

  4. A machine for the preliminary investigation of design features influencing the wear behaviour of knee prostheses.

    PubMed

    McGloughlin, T M; Murphy, D M; Kavanagh, A G

    2004-01-01

    Degradation of tibial inserts in vivo has been found to be multifactorial in nature, resulting in a complex interaction of many variables. A range of kinematic conditions occurs at the tibio-femoral interface, giving rise to various degrees of rolling and sliding at this interface. The movement of the tibio-femoral contact point may be an influential factor in the overall wear of ultra-high molecular weight polyethylene (UHMWPE) tibial components. As part of this study a three-station wear-test machine was designed and built to investigate the influence of rolling and sliding on the wear behaviour of specific design aspects of contemporary knee prostheses. Using the machine, it is possible to monitor the effect of various slide roll ratios on the performance of contemporary bearing designs from a geometrical and materials perspective.

  5. The effect of real-time aging on the oxidation and wear of highly cross-linked UHMWPE acetabular liners.

    PubMed

    Wannomae, Keith K; Christensen, Steven D; Freiberg, Andrew A; Bhattacharyya, Shayan; Harris, William H; Muratoglu, Orhun Kamil

    2006-03-01

    Irradiation decreases the wear of ultra-high molecular weight polyethylene (UHMWPE) but generates residual free radicals, precursors to long-term oxidation. Melting or annealing is used in quenching free radicals. We hypothesized that irradiated and once-annealed UHMWPE would oxidize while irradiated and melted UHMWPE would not, and that the oxidation in the former would increase wear. Acetabular liners were real-time aged by immersion in an aqueous environment that closely mimicked the temperature and oxygen concentration of synovial fluid. After 95 weeks of real-time aging, once-annealed components were oxidized; the melted components were not. The wear rate of the real-time aged irradiated and once-annealed components was higher than the literature reported values of other contemporary highly cross-linked UHMWPEs. Single annealing after irradiation used with terminal gamma sterilization may adversely affect the long-term oxidative stability of UHMWPE components.

  6. Physical properties and biocompatibility of UHMWPE-derived materials modified by synchrotron radiation.

    PubMed

    Bykova, Iu; Weinhardt, V; Kashkarova, A; Lebedev, S; Baumbach, T; Pichugin, V; Zaitsev, K; Khlusov, I

    2014-08-01

    The applications of synchrotron radiation (SR) in medical imaging have become of great use, particularly in angiography, bronchography, mammography, computed tomography, and X-ray microscopy. Thanks to recently developed phase contrast imaging techniques non-destructive preclinical testing of low absorbing materials such as polymers has become possible. The focus of the present work is characterization and examination of UHMWPE-derived materials widely used in medicine, before and after their exposure to SR during such testing. Physical properties, such as wettability, surface energy, IR-spectroscopy, roughness, optical microscopy, microhardness measurements of UHMWPE samples were studied before and after SR. The relationship between a growth of UHMWPE surface hydrophilicity after SR and surface colonization by stromal cells was studied in vitro. Obtained results demonstrate that SR may be used as prospective direction to examine bulk (porous) structure of polymer materials and/or to modify polymer surface and volume for tissue engineering.

  7. EFFECTS OF TRITIUM EXPOSURE ON UHMW-PE, PTFE, AND VESPEL

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Clark, E; Kirk Shanahan, K

    2006-05-31

    Samples of three polymers, Ultra-High Molecular Weight Polyethylene (UHMW-PE), polytetrafluoroethylene (PTFE, also known as Teflon{reg_sign}), and Vespel{reg_sign} polyimide were exposed to 1 atmosphere of tritium gas at ambient temperature for varying times up to 2.3 years in closed containers. Sample mass and size measurements (to calculate density), spectra-colorimetry, dynamic mechanical analysis (DMA), and Fourier-transform infrared spectroscopy (FT-IR) were employed to characterize the effects of tritium exposure on these samples. Changes of the tritium exposure gas itself were characterized at the end of exposure by measuring total pressure and by mass spectroscopic analysis of the gas composition. None of the polymersmore » exhibited significant changes of density. The color of initially white UHMW-PE and PTFE dramatically darkened to the eye and the color also significantly changed as measured by colorimetry. The bulk of UHMW-PE darkened just like the external surfaces, however the fracture surface of PTFE appeared white compared to the PTFE external surfaces. The white interior could have been formed while the sample was breaking or could reflect the extra tritium dose at the surface directly from the gas. The dynamic mechanical response of UHMW-PE was typical of radiation effects on polymers- an initial stiffening (increased storage modulus) and reduction of viscous behavior after three months exposure, followed by lowering of the storage modulus after one year exposure and longer. The storage modulus of PTFE increased through about nine months tritium exposure, then the samples became too weak to handle or test using DMA. Characterization of Vespel{reg_sign} using DMA was problematic--sample-to-sample variations were significant and no systematic change with tritium exposure could be discerned. Isotopic exchange and incorporation of tritium into UHMW-PE (exchanging for protium) and into PTFE (exchanging for fluorine) was observed by FT-IR using an

  8. Biocompatibility evaluation of HDPE-UHMWPE reinforced β-TCP nanocomposites using highly purified human osteoblast cells.

    PubMed

    Shokrgozar, M A; Farokhi, M; Rajaei, F; Bagheri, M H A; Azari, Sh; Ghasemi, I; Mottaghitalab, F; Azadmanesh, K; Radfar, J

    2010-12-15

    Biocompatibility of β-TCP/HDPE-UHMWPE nanocomposite as a new bone substitute material was evaluated by using highly purified human osteoblast cells. Human osteoblast cells were isolated from bone tissue and characterized by immunofluorescence Staining before and after purification using magnetic bead system. Moreover, proliferation, alkaline phosphatase production, cell attachment, calcium deposition, gene expression, and morphology of osteoblast cells on β-TCP/HDPE-UHMWPE nanocomposites were evaluated. The results have shown that the human osteoblast cells were successfully purified and were suitable for subsequent cell culturing process. The high proliferation rate of osteoblast cells on β-TCP/HDPE-UHMWPE nanocomposite confirmed the great biocompatibility of the scaffold. Expression of bone-specific genes was taken place after the cells were incubated in composite extract solutions. Furthermore, osteoblast cells were able to mineralize the matrix next to composite samples. Scanning electron microscopy demonstrated that cells had normal morphology on the scaffold. Thus, these results indicated that the nanosized β-TCP/HDPE-UHMWPE blend composites could be potential scaffold, which is used in bone tissue engineering. Copyright © 2010 Wiley Periodicals, Inc.

  9. Histopathological Analysis of PEEK Wear Particle Effects on the Synovial Tissue of Patients

    PubMed Central

    Jansson, V.; Giurea, A.

    2016-01-01

    Introduction. Increasing interest developed in the use of carbon-fiber-reinforced-poly-ether-ether-ketones (CFR-PEEK) as an alternative bearing material in knee arthroplasty. The effects of CFR-PEEK wear in in vitro and animal studies are controversially discussed, as there are no data available concerning human tissue. The aim of this study was to analyze human tissue containing CFR-PEEK as well as UHMWPE wear debris. The authors hypothesized no difference between the used biomaterials. Methods and Materials. In 10 patients during knee revision surgery of a rotating-hinge-knee-implant-design, synovial tissue samples were achieved (tibial inserts: UHMWPE; bushings and flanges: CFR-PEEK). One additional patient received revision surgery without any PEEK components as a control. The tissue was paraffin-embedded, sliced into 2 μm thick sections, and stained with hematoxylin and eosin in a standard process. A modified panoptical staining was also done. Results. A “wear-type” reaction was seen in the testing and the control group. In all samples, the UHMWPE particles were scattered in the tissue or incorporated in giant cells. CFR-PEEK particles were seen as conglomerates and only could be found next to vessels. CFR-PEEK particles showed no giant-cell reactions. In conclusion, the hypothesis has to be rejected. UHMWPE and PEEK showed a different scatter-behavior in human synovial tissue. PMID:27766256

  10. UHMWPE Sublaminar Wires in Posterior Spinal Instrumentation: Stability and Biocompatibility Assessment in an Ovine Pilot Study.

    PubMed

    Bogie, Rob; Voss, Laura; Arts, Jacobus J; Lataster, Arno; Willems, Paul C; Brans, Boudewijn; van Rhijn, Lodewijk W; Welting, Tim J M

    2016-12-01

    An animal study. To explore ultra-high molecular weight polyethylene (UHMWPE) sublaminar wires in spinal surgery and to assess stability and biocompatibility of the UHMWPE instrumentation in an ovine model. Sublaminar wiring is a well-established technique in segmental scoliosis surgery. However, during introduction and/or removal of the metal sublaminar wires, neurological problems can occur. Abrasion after cutting metal wires for removal can lead to damage to the dural sac. Sublaminar wires have to withhold large forces and breakage of the wires can occur. Different types of sublaminar wires have been developed to address these problems. UHMWPE sublaminar wires can potentially substitute currently used metal sublaminar metal wires. In vivo testing and biocompatibility analysis of UHMWPE wires are recommended before clinical use in spinal surgery. In 6 immature sheep, pedicle screws were instrumented at lumbar level L4 and attached with titanium rods to 4 thoracolumbar vertebrae using 3- and 5-mm-wide UHMWPE sublaminar wiring constructions in 5 animals. Titanium sublaminar wires were applied in 1 animal to function as a control subject. After a follow-up period of 16 weeks, the animals were sacrificed and the spines were isolated. Radiographs and computed tomography (CT) scans were made to assess stability of the instrumentation. The vertebrae were dissected for macroscopic and histologic evaluation. None of the wires had loosened and the instrumentation remained stable. CT scans and radiographs showed no signs of failure of the instrumentation and no neurological complications occurred. Although several bony bridges were seen on CT, growth was observed at the operated levels. Biocompatibility was assessed by macroscopical and histologic analysis, showing no signs of dural or epidural inflammation. This pilot animal study shows that UHMWPE sublaminar wiring is a safe technique. The UHMWPE wires are biocompatible and provide sufficient stability in spinal

  11. Effect of Boundary Conditions on the Back Face Deformations of Flat UHMWPE Panels

    DTIC Science & Technology

    2014-12-01

    Zhang [2] carried out a numerical study of the effects of clamping type and clamping pressure on the ballistic performance of woven Kevlar , and found...effects of composite size were also studied. Singletary [5] studied the effects of boundary conditions and panel sizes on V50 for Kevlar KM2 fabric. The...on the BFD in flat UHMWPE panels. UHMWPE possesses high tenacity and high strength compared to Kevlar , as a result of which it is the material of

  12. Viscoplastic crack initiation and propagation in crosslinked UHMWPE from clinically relevant notches up to 0.5mm radius.

    PubMed

    Sirimamilla, P Abhiram; Rimnac, Clare M; Furmanski, Jevan

    2018-01-01

    Highly crosslinked UHMWPE is now the material of choice for hard-on-soft bearing couples in total joint replacements. However, the fracture resistance of the polymer remains a design concern for increased longevity of the components in vivo. Fracture research utilizing the traditional linear elastic fracture mechanics (LEFM) or elastic plastic fracture mechanics (EPFM) approach has not yielded a definite failure criterion for UHMWPE. Therefore, an advanced viscous fracture model has been applied to various notched compact tension specimen geometries to estimate the fracture resistance of the polymer. Two generic crosslinked UHMWPE formulations (remelted 65kGy and remelted 100kGy) were analyzed in this study using notched test specimens with three different notch radii under static loading conditions. The results suggest that the viscous fracture model can be applied to crosslinked UHMWPE and a single value of critical energy governs crack initiation and propagation in the material. To our knowledge, this is one of the first studies to implement a mechanistic approach to study crack initiation and propagation in UHMWPE for a range of clinically relevant stress-concentration geometries. It is believed that a combination of structural analysis of components and material parameter quantification is a path to effective failure prediction in UHMWPE total joint replacement components, though additional testing is needed to verify the rigor of this approach. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. A Comparison of 2 Tibial Inserts of Different Constraint for Cruciate-Retaining Primary Total Knee Arthroplasty: An Additional Tool for Balancing the Posterior Cruciate Ligament.

    PubMed

    Emerson, Roger H; Barrington, John W; Olugbode, Seun A; Alnachoukati, Omar K

    2016-02-01

    Frequently, a normal posterior-cruciate ligament (PCL) is removed at the surgeon's discretion, converting the normal 4-ligament knee to a 2-ligament knee, thus eliminating the need to balance all 4 ligaments. The development of modular tibial components has led to the availability of differing polyethylene inserts that permit adjustment to the flexion gap independent of the extension gap, permitting PCL balancing not previously available. The purpose of this study is to analyze a specific cruciate-retaining (CR) prosthesis which has 2 polyethylene inserts intended for CR knee use. Between February 2004 and February 2013, the senior author (R.H.E.) has performed 930 total knee arthroplasties using the CR flat insert and 424 knees using the CR lipped insert. The inserts were selected during surgery, based on the assessed tension and function of the PCL. The patients were followed up as part of a prospective total joint program with the Knee Society clinical scoring, range of motion, complications, revisions, preoperative coronal deformity, gender, body mass index, and status of the anterior-cruciate ligament intraoperatively. The average Knee Score was 92.4 for the flat group and 92.1 for the lipped group. Average knee flexion was 116.2° for the flat group and 114.4° for the lipped group (P=.2). Average knee extension (flexion deformity) was 2.1° for the flat group and 0.9° for the lipped group The results reported here show that clinical outcomes and survivorship were no different for either insert option, leading to indirect evidence that appropriate soft tissue balance had been achieved. Published by Elsevier Inc.

  14. Radiation synthesis of a new amidoximated UHMWPE fibrous adsorbent with high adsorption selectivity for uranium over vanadium in simulated seawater

    NASA Astrophysics Data System (ADS)

    Gao, Qianhong; Hu, Jiangtao; Li, Rong; Xing, Zhe; Xu, Lu; Wang, Mouhua; Guo, Xiaojing; Wu, Guozhong

    2016-05-01

    A new kind of highly efficient adsorbent material has been fabricated in this study for the purpose of extracting uranium from seawater. Ultra-high molecular weight polyethylene (UHMWPE) fiber was used as a trunk material for the adsorbent, which was prepared by a series of modification reactions, as follows: (1) grafting of glycidyl methacrylate (GMA) and methyl acrylate (MA) onto UHMWPE fibers via 60Co γ-ray pre-irradiation; (2) aminolyzation of UHMWPE fiber by the ring-opening reaction between of epoxy groups PGMA and ethylene diamine (EDA); (3) Michael addition of amino groups with acrylonitrile (AN) to yield nitrile groups; (4) amidoximation of the attached nitrile moieties by hydroxylamine in dimethyl sulfoxide-water mixture. Modified UHMWPE fibers were characterized by means of attenuated total reflectance-Fourier transformed infrared spectroscopy (ATR-FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) to confirm the attachment of amidoxime (AO) groups onto the UHMWPE fibers. The results of X-ray diffraction (XRD) and single fiber tensile strength verified that the modified UHMWPE fiber retained excellent mechanical properties at a low absorbed radiation dose. The adsorption performance of the UHMWPE fibrous adsorbent was evaluated by subjecting it to an adsorption test in simulated seawater using a continuous-flow mode. The amount of uranium adsorbed by this AO-based UHMWPE fibrous adsorbent was 1.97 mg-U/g after 42 days. This new adsorbent also showed high selectivity for the uranyl ion, and its selectivity for metal ions was found to decrease in the following order: U>Cu>Fe>Ca>Mg>Ni>Zn>Pb>V>Co. The adsorption selectivity for uranium is significantly higher than that for vanadium. In addition, preparation of this modified adsorbent consumes much smaller amounts of the toxic acrylonitrile monomer than the conventional preparation methods of AO-based polyethylene fibers.

  15. Influence of medial parapatellar nail insertion on alignment in proximal tibia fractures--special consideration of the fracture level.

    PubMed

    Weninger, Patrick; Tschabitscher, Manfred; Traxler, Hannes; Pfafl, Veronika; Hertz, Harald

    2010-04-01

    Although a lateral starting point for tibial nailing is recommended to avoid valgus misalignment, higher rates of intra-articular damage were described compared with a medial parapatellar approach. The aim of this anatomic study was to evaluate the fracture level allowing for a safe medial nail entry point without misalignment or dislocation of fragments. Thirty-two fresh-frozen cadaver lower extremities were used to create 1-cm osteotomies at four different levels (n = 8) from 2 cm to 8 cm below the tibial tuberosity. Nine-millimeter unreamed solid titanium tibial nails (Connex, I.T.S. Spectromed, Lassnitzhohe, Austria) were inserted from a medial parapatellar incision. Misalignment (degree) and dislocation of the distal fragment were measured in the frontal and sagittal plane. A medial parapatellar approach for tibial nail insertion mainly caused valgus and anterior bow misalignment and ventral and medial fragment displacement. Mean misalignment and fragment displacement did not exceed 0.5 degree if the osteotomy was performed 8 cm to 9 cm below the tibial tuberosity. According to the results of this study, a medial parapatellar approach can be performed without misalignment and fragment dislocation in proximal tibia fractures extending 8 cm or more below the tibial tuberosity.

  16. Simulation of tibial counterface wear in mobile bearing knees with uncoated and ADLC coated surfaces.

    PubMed

    Jones, V C; Barton, D C; Auger, D D; Hardaker, C; Stone, M H; Fisher, J

    2001-01-01

    A multidirectional pin-on-plate reciprocating machine was used to compare the wear performance of UHMWPE sliding against cast cobalt chrome (CoCr) plates that were either untreated or coated with Amorphous Diamond Like Carbon (ADLC). The test conditions were based on a 1/5 scale model representative of in vivo motion at the tibial counterfaces of unconstrained mobile bearing knees. The average +/- STERR wear rates were 13.78+/-1.06 mm3/Mcycles for the ADLC counterfaces and 0.504+/-0.12 mm3/Mcycles for the control CoCr counterfaces. All of the pins run on the ADLC counterfaces exhibited the same patterns of blistering along the central axis, and severe abrasion elsewhere to the extent that all of the original machining marks were removed after just one week of testing. The average value of friction coefficient was 0.24 for the ADLC counterfaces and 0.073 for the control CoCr counterfaces. The factor of 3.5 increase was statistically significant at p < 0.05. In the tribological evaluation of ADLC coatings for tibial trays in mobile bearing knees, this study shows that this specific Physical Vapour Deposition (PVD) ADLC showed significantly poorer frictional and wear performance than uncoated surfaces which was sufficient to negate any potential benefits of improved resistance to third body damage.

  17. A novel alginate-encapsulated system to study biological response to critical-sized wear particles of UHMWPE loaded with alendronate sodium.

    PubMed

    Liu, Yumei; Shi, Feng; Bo, Lin; Zhi, Wei; Weng, Jie; Qu, Shuxin

    2017-10-01

    The aim of this study was to develop a novel alginate-encapsulated system (Alg beads) to investigate the cell response to critical-sized wear particles of ultra-high molecular weight polyethylene loaded with alendronate sodium (UHMWPE-ALN), one of the most effective drugs to treat bone resorption in clinic. The extrusion method was used to prepare Alg beads encapsulating rat calvarial osteoblasts (RCOs) and critical-sized UHMWPE-ALN wear particles with spherical morphology and uniform size. The morphology, permeability and stability of Alg beads were characterized. The proliferation, ALP activity, cell apoptosis and distribution of live/dead RCOs co-cultured with wear particles in Alg beads were evaluated. RCOs and critical-sized UHMWPE-ALN wear particles distributed evenly and contacted efficiently in Alg beads. Alg beads were both permeable to trypsin and BSA, while the smaller the molecular was, the larger the diffuse was. The proliferation of RCOs in Alg beads increased with time, which indicated that Alg beads provided suitable conditions for cell culture. The long-term stability of Alg beads indicated the possibility for the longer time of co-cultured cells with wear particles. Critical-sized UHMWPE-ALN and UHMWPE wear particles both inhibited the proliferation and differentiation of RCOs, and induced the apoptosis of RCOs encapsulated in Alg beads. However, these effects could be significantly alleviated by the ALN released from the critical-sized UHMWPE-ALN wear particles. The present results suggested that this novel-developed co-culture system was feasible to evaluate the cell response to critical-sized UHMWPE-ALN wear particles for a longer time. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Effect of consolidation on adhesive and abrasive wear of ultra high molecular weight polyethylene.

    PubMed

    Gul, Rizwan M; McGarry, Frederick J; Bragdon, Charles R; Muratoglu, Orhun K; Harris, William H

    2003-08-01

    Total hip replacement (THR) is widely performed to recover hip joint functions lost by trauma or disease and to relieve pain. The major cause of failure in THR is the wear of the ultra high molecular weight polyethylene (UHMWPE) component. The dominant wear mechanism in THR occurs through adhesion and abrasion. While poor consolidation of UHMWPE is known to increase the incidence of a different damage mode, delamination, which is the dominant wear mechanism in tibial inserts but uncommon in THR, the effect of consolidation on adhesive and abrasive wear of UHMWPE is not clear. In this study UHMWPE resin was subjected to hot isostatic pressing under a pressure of 138MPa at different temperatures (210 degrees C, 250 degrees C, and 300 degrees C) to achieve varying degrees of consolidation. The extent of consolidation was determined by optical microscopy using thin sections, and by scanning electron microscopy using cryofractured and solvent etched specimens. Wear behavior of the samples with varying degree of consolidation was determined using a bi-directional pin-on-disc machine simulating conditions in a hip joint. Increasing the processing temperature decreased the incidence of fusion defects and particle boundaries reflecting the powder flakes of the virgin resin, improving the consolidation. However, the bi-directional pin-on-disc wear rate did not change with the processing temperature, indicating that adhesive and abrasive wear is independent of the extent of consolidation in the range of parameters studied here.

  19. Technique tip: use of anterior cruciate ligament jig for hindfoot fusion by calcanio-talo-tibial nail.

    PubMed

    Haque, Syed; Sarkar, Jay

    2012-08-01

    The use of intramedullary nail fixation for tibio-talo-calcaneal fusion is gaining popularity. There is chance of failure of procedure following faulty operative technique specially alignment. The article describes a useful application of tibial tunnel jig in inserting the calcanio-talo-tibial guide wire. There is precision of few millimeters in the exit point of guide wire on talus. The authors believe that this helps in better positioning of nail and hence better alignment and better operative outcome.

  20. Anthropometric measurements of tibial plateau and correlation with the current tibial implants.

    PubMed

    Erkocak, Omer Faruk; Kucukdurmaz, Fatih; Sayar, Safak; Erdil, Mehmet Emin; Ceylan, Hasan Huseyin; Tuncay, Ibrahim

    2016-09-01

    The aim of the study was to make an anthropometric analysis at the resected surfaces of the proximal tibia in the Turkish population and to compare the data with the dimensions of tibial components in current use. We hypothesized that tibial components currently available on the market do not fulfil the requirements of this population and a new tibial component design may be required, especially for female patients with small stature. Anthropometric data from the proximal tibia of 226 knees in 226 Turkish subjects were measured using magnetic resonance imaging. We measured the mediolateral, middle anteroposterior, medial and lateral anteroposterior dimensions and the aspect ratio of the resected proximal tibial surface. All morphological data were compared with the dimensions of five contemporary tibial implants, including asymmetric and symmetric design types. The dimensions of the tibial plateau of Turkish knees demonstrated significant differences according to gender (P < 0.05). Among the different tibial implants reviewed, neither asymmetric nor symmetric designs exhibited a perfect conformity to proximal tibial morphology in size and shape. The vast majority of tibial implants involved in this study tend to overhang anteroposteriorly, and a statistically significant number of women (21 %, P < 0.05) had tibial anteroposterior diameters smaller than the smallest available tibial component. Tibial components designed according to anthropometric measurements of Western populations do not perfectly meet the requirements of Turkish population. These data could provide the basis for designing the optimal and smaller tibial component for this population, especially for women, is required for best fit. II.

  1. The elimination of free radicals in irradiated UHMWPEs with and without vitamin E stabilization by annealing under pressure.

    PubMed

    Oral, Ebru; Ghali, Bassem W; Muratoglu, Orhun K

    2011-04-01

    Radiation crosslinking of ultrahigh molecular weight polyethylene (UHMWPE) has been used to decrease the wear of joint implant bearing surfaces. While radiation crosslinking has been successful in decreasing femoral head penetration into UHMWPE acetabular liners in vivo, postirradiation thermal treatment of the polymer is required to ensure the oxidative stability of joint implants in the long term. Two types of thermal treatment have been used: (i) annealing below the melting point preserves the mechanical properties but the residual free radicals trapped in the crystalline regions are not completely eliminated, leading to oxidation in the long-term and (ii) annealing above the melting point (melting) eliminates the free radicals but leads to a decrease in mechanical properties through loss of crystallinity during the melting process. In this study, we hypothesized that free radicals could be reduced by annealing below the melting point under pressure effectively without melting due to the elevation of the melting point. By avoiding the complete melting of UHMWPE, mechanical properties would be preserved. Our hypothesis tested positive in that we found the radiation-induced free radicals to be markedly reduced (below the detection limit of state-of-the-art electron spin resonance) by thermal annealing under pressure in radiation crosslinked virgin UHMWPE and UHMWPE/vitamin-E blends without loss of mechanical properties. Copyright © 2011 Wiley Periodicals, Inc.

  2. Deformation and Stress Response of Carbon Nanotubes/UHMWPE Composites under Extensional-Shear Coupling Flow

    NASA Astrophysics Data System (ADS)

    Wang, Junxia; Cao, Changlin; Yu, Dingshan; Chen, Xudong

    2018-02-01

    In this paper, the effect of varying extensional-shear couple loading on deformation and stress response of Carbon Nanotubes/ ultra-high molecular weight polyethylene (CNTs/UHMWPE) composites was investigated using finite element numerical simulation, with expect to improve the manufacturing process of UHMWPE-based composites with reduced stress and lower distortion. When applying pure extensional loading and pure X-Y shear loading, it was found that the risk of a structural breakage greatly rises. For identifying the coupling between extensional and shear loading, distinct generations of force loading were defined by adjusting the magnitude of extensional loading and X-Y shear loading. It was shown that with the decrement of X-Y shear loading the deformation decreases obviously where the maximal Mises stress in Z-direction at 0.45 m distance is in the range from 24 to 10 MPa and the maximal shear stress at 0.61 m distance is within the range from 0.9 to 0.3 MPa. In addition, all the stresses determined were clearly below the yield strength of CNTs/UHMWPE composites under extensional-shear couple loading.

  3. [Review and prospect of analysis on UHMWPE wear debris in artificial hip joints].

    PubMed

    Wu, Jingping; Yuan, Chengqing; Yan, Xinping

    2010-02-01

    This paper briefly reviews the latest progress in the analyses of the technologies for artificial hip joints; and in the researches directed to the features of UHMWPE debris obtained from all kinds of experimental conditions, to the wear process and wear mechanism, and to the factors which influence the wear mechanism. Furthermore, the signification of debris atlas was illustrated. Finally, future directions to be furthered were considered and envisaged. It is suggested that emphases be laid on the relationship between the UHMWPE debris feature and the wear mechanism, and be laid synergistic effects of biochemical environment and loading environment so as to establish the predictive wear models of artificial hip joints.

  4. Technical Note: Computer-Manufactured Inserts for Prosthetic Sockets

    PubMed Central

    Sanders, Joan E.; McLean, Jake B.; Cagle, John C.; Gardner, David W.; Allyn, Katheryn J.

    2016-01-01

    The objective of this research was to use computer-aided design software and a tabletop 3-D additive manufacturing system to design and fabricate custom plastic inserts for trans-tibial prosthesis users. Shape quality of inserts was tested right after they were inserted into participant’s test sockets and again after four weeks of wear. Inserts remained properly positioned and intact throughout testing. Right after insertion the inserts caused the socket to be slightly under-sized, by a mean of 0.11 mm, approximately 55% of the thickness of a nylon sheath. After four weeks of wear the under-sizing was less, averaging 0.03 mm, approximately 15% of the thickness of a nylon sheath. Thus the inserts settled into the sockets over time. If existing prosthetic design software packages were enhanced to conduct insert design and to automatically generate fabrication files for manufacturing, then computer manufactured inserts may offer advantages over traditional methods in terms of speed of fabrication, ease of design, modification, and record keeping. PMID:27212209

  5. Technical note: Computer-manufactured inserts for prosthetic sockets.

    PubMed

    Sanders, Joan E; McLean, Jake B; Cagle, John C; Gardner, David W; Allyn, Katheryn J

    2016-08-01

    The objective of this research was to use computer-aided design software and a tabletop 3-D additive manufacturing system to design and fabricate custom plastic inserts for trans-tibial prosthesis users. Shape quality of inserts was tested right after they were inserted into participant's test sockets and again after four weeks of wear. Inserts remained properly positioned and intact throughout testing. Right after insertion the inserts caused the socket to be slightly under-sized, by a mean of 0.11mm, approximately 55% of the thickness of a nylon sheath. After four weeks of wear the under-sizing was less, averaging 0.03mm, approximately 15% of the thickness of a nylon sheath. Thus the inserts settled into the sockets over time. If existing prosthetic design software packages were enhanced to conduct insert design and to automatically generate fabrication files for manufacturing, then computer manufactured inserts may offer advantages over traditional methods in terms of speed of fabrication, ease of design, modification, and record keeping. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

  6. Tribological behaviors of UHMWPE composites with different counter surface morphologies

    NASA Astrophysics Data System (ADS)

    Wang, Yanzhen; Yin, Zhongwei; Li, Hulin; Gao, Gengyuan

    2017-12-01

    The influence of counter surface morphologies on hybrid glass fiber (GF) and carbon fiber (CF) filled ultrahigh molecular weight polyethylene (UHMWPE) were studied under various contact pressure and sliding speed against GCr15 steel in dry condition. The goals were to investigate the tribological behavior of GF/CF/UHMWPE composite as a kind of water lubricated journal bearing material. The friction and wear behavior of composites were examined using a pin-on-disc tribometer. The morphologies of the worn surface were examined by scanning electron microscopy (SEM) and laser 3D micro-imaging and profile measurement. Generally, the wear rate and friction coefficient of composites increase as the increment of counter surface roughness. The friction coefficient increases firstly and then decrease with an increase in sliding speed and contact pressure for counterface with Ra=0.2 and 3.5 μm, while the friction coefficient decreased for counterface with Ra=0.6 μm.

  7. Fractography evolution in accelerated aging of UHMWPE after gamma irradiation in air.

    PubMed

    Medel, F; Gómez-Barrena, E; García-Alvarez, F; Ríos, R; Gracia-Villa, L; Puértolas, J A

    2004-01-01

    We studied the fracture surface evolution of ultra high molecular weight polyethylene (UHMWPE) specimens, manufactured from GUR 1050 compression moulded sheets, after gamma sterilisation in air followed by different aging times after thermal treatment at 120 degrees C. Degradation profiles were obtained by FTIR and DSC measurements after 0, 7, 14, 24 and 36h aging. We observed by SEM the morphology patterns at these aging times, in surface fractographies after uniaxial tensile test of standardised samples. The results pointed out clear differences between short and long aging times. At shorter times, 7h, the behaviour was similar to non-degraded UHMWPE, exhibiting ductile behaviour. At longer times, 24-36h, this thermal protocol provided a highly degraded zone in the subsurface, similar to the white band found after gamma irradiation in air followed by natural aging, although closer to the surface, at 150-200mum. The microstructure of this oxidation zone, similarly found in gamma irradiated samples shelf-aged for 6-7 years, although with different distribution of microvoids, was formed by fibrils, associated with embrittlement of the oxidised UHMWPE. In addition, the evolution of the oxidation index, the enthalpy content, the mechanical parameters, and the depth of the oxidation front deduced from the fractographies versus aging time showed that a changing behaviour in the degradation rate appeared at intermediate aging times.

  8. Variation of mechanical properties and oxidation with radiation dose and source in highly crosslinked remelted UHMWPE.

    PubMed

    Fung, Mitchell; Bowsher, John G; Van Citters, Douglas W

    2018-06-01

    Ultra-high molecular weight polyethylene (UHMWPE) is the current gold standard for bearing materials used in total joint arthroplasty. High-dose radiation is commonly used to crosslink UHMWPE, thereby improving its wear resistance. A subsequent remelting step eliminates trapped residual free radicals to promote oxidative stability on the shelf, and to prevent material degradation over the long term. Assessment of clinically retrieved, highly crosslinked UHMWPE devices shows signs of unanticipated oxidation occurring in vivo, despite the absence of free radicals prior to implantation. These findings warrant further investigation into possible factors impacting this phenomenon along with its clinical implications. The overall objective of this work is to quantify the influence of irradiation dose and source on UHMWPE's oxidative stability, along with the effects of oxidation on the ultimate mechanical properties, including strength, ductility, and toughness. The results showed a strong positive correlation between maximum oxidation and initial transvinylene content. Critical oxidation levels in the context of mechanical property loss were determined for e-beam and gamma treatments at various radiation doses. Further, it was shown that critical oxidation was more dependent on radiation dose and less dependent on source. If in vivo oxidation persists in these devices, this can potentially lead to mechanical failure (e.g. fatigue damage) as observed in terminally gamma-sterilized devices. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Kinematically aligned total knee arthroplasty limits high tibial forces, differences in tibial forces between compartments, and abnormal tibial contact kinematics during passive flexion.

    PubMed

    Roth, Joshua D; Howell, Stephen M; Hull, Maury L

    2018-06-01

    Following total knee arthroplasty (TKA), high tibial forces, large differences in tibial forces between the medial and lateral compartments, and anterior translation of the contact locations of the femoral component on the tibial component during passive flexion indicate abnormal knee function. Because the goal of kinematically aligned TKA is to restore native knee function without soft tissue release, the objectives were to determine how well kinematically aligned TKA limits high tibial forces, differences in tibial forces between compartments, and anterior translation of the contact locations of the femoral component on the tibial component during passive flexion. Using cruciate retaining components, kinematically aligned TKA was performed on thirteen human cadaveric knee specimens with use of manual instruments without soft tissue release. The tibial forces and tibial contact locations were measured in both the medial and lateral compartments from 0° to 120° of passive flexion using a custom tibial force sensor. The average total tibial force (i.e. sum of medial + lateral) ranged from 5 to 116 N. The only significant average differences in tibial force between compartments occurred at 0° of flexion (29 N, p = 0.0008). The contact locations in both compartments translated posteriorly in all thirteen kinematically aligned TKAs by an average of 14 mm (p < 0.0001) and 18 mm (p < 0.0001) in the medial and lateral compartments, respectively, from 0° to 120° of flexion. After kinematically aligned TKA, average total tibial forces due to the soft tissue restraints were limited to 116 N, average differences in tibial forces between compartments were limited to 29 N, and a net posterior translation of the tibial contact locations was observed in all kinematically aligned TKAs during passive flexion from 0° to 120°, which are similar to what has been measured previously in native knees. While confirmation in vivo is warranted, these findings give

  10. Evaluation of carbon nanotubes and graphene as reinforcements for UHMWPE-based composites in arthroplastic applications: A review.

    PubMed

    Puértolas, J A; Kurtz, S M

    2014-11-01

    In this review we have evaluated the state of the art of CNT/UHMWPE and graphene/UHMWPE composites from four different points of view: mechanical properties, chemical stability, wear resistance and biocompatibility. The performance of these new carbonaceous composites allows us to conclude that these materials have overcome a first step on the way to developing into an alternative to the current HXLPEs used in orthopedic applications. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Medial Tibial Stress Shielding: A Limitation of Cobalt Chromium Tibial Baseplates.

    PubMed

    Martin, J Ryan; Watts, Chad D; Levy, Daniel L; Kim, Raymond H

    2017-02-01

    Stress shielding is a well-recognized complication associated with total knee arthroplasty. However, this phenomenon has not been thoroughly described. Specifically, no study to our knowledge has evaluated the radiographic impact of utilizing various tibial component compositions on tibial stress shielding. We retrospectively reviewed 3 cohorts of 50 patients that had a preoperative varus deformity and were implanted with a titanium, cobalt chromium (CoCr), or an all polyethylene tibial implant. A radiographic comparative analysis was performed to evaluate the amount of medial tibial bone loss in each cohort. In addition, a clinical outcomes analysis was performed on the 3 cohorts. The CoCr was noted to have a statistically significant increase in medial tibial bone loss compared with the other 2 cohorts. The all polyethylene cohort had a statistically significantly higher final Knee Society Score and was associated with the least amount of stress shielding. The CoCr tray is the most rigid of 3 implants that were compared in this study. Interestingly, this cohort had the highest amount of medial tibial bone loss. In addition, 1 patient in the CoCr cohort had medial soft tissue irritation which was attributed to a prominent medial tibial tray which required revision surgery to mitigate the symptoms. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Wear studies of all UHMWPE couples under various bio-tribological conditions.

    PubMed

    Joyce, T J; Unsworth, A

    2004-01-01

    Wear tests were undertaken in which ultra high molecular weight polyethylene (UHMWPE) was rubbed against itself. Tests primarily employed a pin-on-plate wear test machine, with distilled water, Ringer solution and dilute bovine serum being used as the lubricants. Loads of 10N and 40N were employed, and some test pins had a rotational motion added. In all cases wear was high, with mean wear factors of up to 91 10 -6 mm3/Nm being measured, but the addition of rotation reduced the amount of material worn from the test plates. In the presence of bovine serum and under reciprocation only, pin wear was relatively low. With bovine serum as the lubricant, total mean wear factors for the UHMWPE couples were calculated to be in the range of 35 to 58 10-6mm3/Nm. Therefore the pin-on-plate tests showed that the choice of lubricant as well as the motion applied to the test pin had a significant influence on the wear volumes measured. A two-piece UHMWPE 'prosthesis' with matching hemispherical faces was fabricated and tested on a finger simulator. Distilled water was used as the lubricant and wear factors were found to be greater for the metacarpal component, 21 10 -6mm3/Nm, than the phalangeal component, 3 10-6mm3/Nm, after ten million cycles of testing. This result paralleled the greater wear seen by the plate than by the pin in the pin-on-plate tests under reciprocating motion. (Journal of Applied Biomaterials & Biomechanics 2004; 2: 29-34).

  13. [Research progress of polyethylene inserts wear measurement and evaluation in total knee arthroplasty].

    PubMed

    Zhao, Feng; Wang, Chuan; Fan, Yubo

    2015-01-01

    Wear of polyethylene (PE) tibial inserts is a significant cause of implant failure of total knee arthroplasty (TKA). PE inserts wear measurement and evaluation is the key in TKA researches. There are many methods to measure insert wear. Qualitative methods such as observation are used to determine the wear and its type. Quantitative methods such as gravimetric analysis, coordinate measuring machines (CMM) and micro-computed tomography (micro-CT) are used to measure the mass, volume and geometry of wear. In this paper, the principle, characteristics and research progress of main insert wear evaluation method were introduced and the problems and disadvantages were analyzed.

  14. Posterior medial meniscus-femoral insertion into the anterior cruciate ligament. A case report.

    PubMed

    Bhargava, A; Ferrari, D A

    1998-03-01

    Medial meniscal anomalies are rare. The anterior horn insertion into the anterior cruciate ligament is the most common. In the course of an arthroscopy for torn lateral meniscus, an anomalous band in continuity with the posterior horn of the medial meniscus was observed to insert into the anterior cruciate ligament. Although the tibial portion of the anterior cruciate was redundant, the anomalous band provided tension to the anterior cruciate ligament and a negative pivot shift. A previously unreported posterior medial meniscal femoral insertion is described.

  15. Modeling Ballistic Response of Ultra-High-Molecular-Weight Polyethylene (UHMWPE)

    DTIC Science & Technology

    2016-07-01

    posttest panels. Fig. 5 Variables to be compared between model and experiments The 6 tests and available test data are listed in Table 2. The first 3...Time history of center BFD for the 3 BFD tests Figure 24 shows the damages in the panels from posttest CT scan of the UHMWPE panels and the

  16. High temperature homogenization improves impact toughness of vitamin E-diffused, irradiated UHMWPE.

    PubMed

    Oral, Ebru; O'Brien, Caitlin; Doshi, Brinda; Muratoglu, Orhun K

    2017-06-01

    Diffusion of vitamin E into radiation cross-linked ultrahigh molecular weight polyethylene (UHMWPE) is used to increase stability against oxidation of total joint implant components. The dispersion of vitamin E throughout implant preforms has been optimized by a two-step process of doping and homogenization. Both of these steps are performed below the peak melting point of the cross-linked polymer (<140°C) to avoid loss of crystallinity and strength. Recently, it was discovered that the exposure of UHMWPE to elevated temperatures, around 300°C, for a limited amount of time in nitrogen, could improve the toughness without sacrificing wear resistance. We hypothesized that high temperature homogenization of antioxidant-doped, radiation cross-linked UHMWPE could improve its toughness. We found that homogenization at 300°C for 8 h resulted in an increase in the impact toughness (74 kJ/m 2 compared to 67 kJ/m 2 ), the ultimate tensile strength (50 MPa compared to 43 MPa) and elongation at break (271% compared to 236%). The high temperature treatment did not compromise the wear resistance or the oxidative stability as measured by oxidation induction time. In addition, the desired homogeneity was achieved at a much shorter duration (8 h compared to >240 h) by using high temperature homogenization. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1343-1347, 2017. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  17. Distal Insertions of the Biceps Femoris

    PubMed Central

    Branch, Eric A.; Anz, Adam W.

    2015-01-01

    Background: Avulsion of the biceps femoris from the fibula and proximal tibia is encountered in clinical practice. While the anatomy of the primary posterolateral corner structures has been qualitatively and quantitatively described, a quantitative analysis regarding the insertions of the biceps femoris on the fibula and proximal tibia is lacking. Purpose: To quantitatively assess the insertions of the biceps femoris, fibular collateral ligament (FCL), and anterolateral ligament (ALL) on the fibula and proximal tibia as well as establish relationships among these structures and to pertinent surgical anatomy. Study Design: Descriptive laboratory study. Methods: Dissections were performed on 12 nonpaired, fresh-frozen cadaveric specimens identifying the biceps femoris, FCL, and ALL, and their insertions on the proximal tibia and fibula. The footprint areas, orientations, and distances from relevant osseous landmarks were measured using a 3-dimensional coordinate measurement device. Results: Dissection produced 6 easily identifiable and reproducible anatomic footprints. Tibial footprints included the insertion of the ALL and an insertion of the biceps femoris (TBF). Fibular footprints included the insertion of the FCL, a distal insertion of the biceps femoris (DBF), a medial footprint of the biceps femoris (MBF), and a proximal footprint of the biceps femoris (PBF). The mean area of these footprints (95% CI) was as follows: ALL, 53.0 mm2 (38.4-67.6); TBF, 93.9 mm2 (72.0-115.8); FCL, 86.8 mm2 (72.3-101.2); DBF, 119 mm2 (91.1-146.9); MBF, 46.8 mm2 (29.0-64.5); and PBF, 215 mm2 (192.4-237.5). The mean distance (95% CI) from the Gerdy tubercle to the center of the ALL footprint was 24.3 mm (21.6-27.0) and to the center of the TBF was 22.5 mm (21.0-24.0). The center of the DBF was 8.68 mm (7.0-10.3) from the anterior border of the fibula, the center of the FCL was 14.6 mm (12.5-16.7) from the anterior border of the fibula and 20.7 mm (19.0-22.4) from the tip of the fibular

  18. Effects of tibial slope changes in the stability of fixed bearing medial unicompartmental arthroplasty in anterior cruciate ligament deficient knees.

    PubMed

    Suero, Eduardo M; Citak, Musa; Cross, Michael B; Bosscher, Marianne R F; Ranawat, Anil S; Pearle, Andrew D

    2012-08-01

    Patients with anterior cruciate ligament (ACL) deficiency may have increased failure rates with UKA as a result of abnormal contact stresses and altered knee kinematics. Variations in the slope of the tibial component in UKA may alter tibiofemoral translation, and affect outcomes. This cadaveric study evaluated tibiofemoral translation during the Lachman and pivot shift tests after changing the slope of a fixed bearing unicondylar tibial component. Sectioning the ACL increased tibiofemoral translation in both the Lachman and pivot shift tests (P<0.05). Tibial slope leveling (decreasing the posterior slope) of the polyethylene insert in a UKA decreases anteroposterior tibiofemoral translation in the sagittal plane to a magnitude similar to that of the intact knee. With 8° of tibial slope leveling, anterior tibial translation during the Lachman test decreased by approximately 5mm. However, no variation in slope altered the pivot shift kinematics in the ACL deficient knees. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Proximal Tibial Bone Graft

    MedlinePlus

    ... All Site Content AOFAS / FootCareMD / Treatments Proximal Tibial Bone Graft Page Content What is a bone graft? Bone grafts may be needed for various ... the proximal tibia. What is a proximal tibial bone graft? Proximal tibial bone graft (PTBG) is a ...

  20. The effect of plate position and size on tibial slope in high tibial osteotomy: a cadaveric study.

    PubMed

    Rubino, L Joseph; Schoderbek, Robert J; Golish, S Raymond; Baumfeld, Joshua; Miller, Mark D

    2008-01-01

    Opening wedge high tibial osteotomies are performed for degenerative changes and varus. Opening wedge osteotomies can change proximal tibial slope in the sagittal plane, possibly imparting stability in the ACL-deficient knee. The aim of this study was to assess the effect of plate position and size on change in tibial slope. Eight cadaveric knees underwent opening wedge high tibial osteotomy with Puddu plates of each different size. Plates were placed anterior, central, and posterior for each size used. Lateral radiographs were obtained. Tibial slope was measured and compared with baseline slope. Tibial slope was affected by plate position (P < 0.05) and size (P < 0.001). Smaller, posterior plates had less effect on tibial slope. However, anterior and central plates increased tibial slope over all plate sizes (P < 0.05). This study found that tibial slope increases with opening wedge high tibial osteotomy. Larger corrections and anterior placement of the plate are associated with larger increases in slope.

  1. Effect of crosslinking UHMWPE on its tensile and compressive creep performance.

    PubMed

    Lewis, G; Carroll, M

    2001-01-01

    The in vitro quasi-static tensile and compressive creep properties of three sets of GUR 1050 ultra-high-molecular-weight polyethylene (UHMWPE) specimens were obtained. These sets were: control (as-received stock); "low-gamma" (specimens were crosslinked using gamma radiation, with a minimum dose of 5 Mrad); and "high-gamma" (specimens were crosslinked using gamma radiation, with a minimum dose of 15 Mrad). The % crystallinity (%C) and crosslink density (rho(x)) of the specimens in the three sets were also obtained. It was found that, in both tension and compression, crosslinking resulted in a significant depreciation in the creep properties, relative to control. The trend in the creep results is explained in terms of the impact of crosslinking on the polymer's %C and rho(x). The present results are in contrast to literature reports that show that crosslinking enhances the wear resistance of the polymer. The implications of the present results, taken together with the aforementioned literature results, are fully discussed vis-a-vis the use of crosslinked UHMWPE for fabricating articular components for arthroplasties.

  2. Quantitative Mapping of Matrix Content and Distribution across the Ligament-to-Bone Insertion

    PubMed Central

    Spalazzi, Jeffrey P.; Boskey, Adele L.; Pleshko, Nancy; Lu, Helen H.

    2013-01-01

    The interface between bone and connective tissues such as the Anterior Cruciate Ligament (ACL) constitutes a complex transition traversing multiple tissue regions, including non-calcified and calcified fibrocartilage, which integrates and enables load transfer between otherwise structurally and functionally distinct tissue types. The objective of this study was to investigate region-dependent changes in collagen, proteoglycan and mineral distribution, as well as collagen orientation, across the ligament-to-bone insertion site using Fourier transform infrared spectroscopic imaging (FTIR-I). Insertion site-related differences in matrix content were also evaluated by comparing tibial and femoral entheses. Both region- and site-related changes were observed. Collagen content was higher in the ligament and bone regions, while decreasing across the fibrocartilage interface. Moreover, interfacial collagen fibrils were aligned parallel to the ligament-bone interface near the ligament region, assuming a more random orientation through the bulk of the interface. Proteoglycan content was uniform on average across the insertion, while its distribution was relatively less variable at the tibial compared to the femoral insertion. Mineral was only detected in the calcified interface region, and its content increased exponentially across the mineralized fibrocartilage region toward bone. In addition to new insights into matrix composition and organization across the complex multi-tissue junction, findings from this study provide critical benchmarks for the regeneration of soft tissue-to-bone interfaces and integrative soft tissue repair. PMID:24019964

  3. Development and Characterization of UHMWPE Fiber-Reinforced Hydrogels For Meniscal Replacement

    NASA Astrophysics Data System (ADS)

    Holloway, Julianne Leigh

    Meniscal tears are the most common orthopedic injuries to the human body. The current treatment of choice, however, is a partial meniscectomy that leads to osteoarthritis proportional to the amount of tissue removed. As a result, there is a significant clinical need to develop materials capable of restoring the biomechanical contact stress distribution to the knee after meniscectomy and preventing the onset of osteoarthritis. In this work, a fiber-reinforced hydrogel-based synthetic meniscus was developed that allows for tailoring of the mechanical properties and molding of the implant to match the size, shape, and property distribution of the native tissue. Physically cross-linked poly(vinyl alcohol) (PVA) hydrogels were reinforced with ultrahigh molecular weight polyethylene (UHMWPE) fibers and characterized in compression (0.1-0.8 MPa) and tension (0.1-250 MPa) showing fine control over mechanical properties within the range of the human meniscus. Morphology and crystallinity analysis of PVA hydrogels showed increases in crystallinity and PVA densification, or phase separation, with freeze-thaw cycles. A comparison of freeze-thawed and aged, physically cross-linked hydrogels provided insight on both crystallinity and phase separation as mechanisms for PVA gelation. Results indicated both mechanisms independently contributed to hydrogel modulus for freeze-thawed hydrogels. In vitro swelling studies were performed using osmotic solutions to replicate the swelling pressure present in the knee. Minimal swelling was observed for hydrogels with a PVA concentration of 30-35 wt%, independently of hydrogel freeze-thaw cycles. This allows for independent tailoring of hydrogel modulus and pore structure using freeze-thaw cycles and swelling behavior using polymer concentration to match a wide range of properties needed for various soft tissue applications. The UHMWPE-PVA interface was identified as a significant weakness. To improve interfacial adhesion, a novel

  4. Tibial bone fractures occurring after medioproximal tibial bone grafts for oral and maxillofacial reconstruction.

    PubMed

    Kim, Il-Kyu; Cho, Hyun-Young; Pae, Sang-Pill; Jung, Bum-Sang; Cho, Hyun-Woo; Seo, Ji-Hoon

    2013-12-01

    Oral and maxillofacial defects often require bone grafts to restore missing tissues. Well-recognized donor sites include the anterior and posterior iliac crest, rib, and intercalvarial diploic bone. The proximal tibia has also been explored as an alternative donor site. The use of the tibia for bone graft has many benefits, such as procedural ease, adequate volume of cancellous and cortical bone, and minimal complications. Although patients rarely complain of pain, swelling, discomfort, or dysfunction, such as gait disturbance, both patients and surgeons should pay close attention to such after effects due to the possibility of tibial fracture. The purpose of this study is to analyze tibial fractures that occurring after osteotomy for a medioproximal tibial graft. An analysis was intended for patients who underwent medioproximal tibial graft between March 2004 and December 2011 in Inha University Hospital. A total of 105 subjects, 30 females and 75 males, ranged in age from 17 to 78 years. We investigated the age, weight, circumstance, and graft timing in relation to tibial fracture. Tibial fractures occurred in four of 105 patients. There were no significant differences in graft region, shape, or scale between the fractured and non-fractured patients. Patients who undergo tibial grafts must be careful of excessive external force after the operation.

  5. Early tension loss in an anterior cruciate ligament graft. A cadaver study of four tibial fixation devices.

    PubMed

    Grover, Dustin M; Howell, Stephen M; Hull, Maury L

    2005-02-01

    The tensile force applied to an anterior cruciate ligament graft determines the maximal anterior translation; however, it is unknown whether the tensile force is transferred to the intra-articular portion of the graft and whether the intra-articular tension and maximal anterior translation are maintained shortly after ligament reconstruction. Ten cadaveric knees were reconstructed with a double-looped tendon graft. The graft was looped through a femoral fixation transducer that measured the resultant force on the proximal end of the graft. A pneumatic cylinder applied a tensile force of 110 N to the graft exiting the tibial tunnel with the knee in full extension. The graft was fixed sequentially with four tibial fixation devices (a spiked metal washer, double staples, a bioabsorbable interference screw, and a WasherLoc). Three cyclic loading treatments designed to conservatively load the graft and its fixation were applied. The combined loss in intra-articular graft tension from friction, insertion of the tibial fixation device, and three cyclic loading treatments was 50% for the spiked washer (p = 0.0004), 100% for the double staples (p < 0.0001), 64% for the interference screw (p = 0.0001), and 56% for the WasherLoc (p < 0.0001). The tension loss caused an increase in the maximal anterior translation from that of the intact knee of 2.0 mm for the spiked washer (p = 0.005), 7.8 mm for the double staples (p < 0.0001), 2.7 mm for the interference screw (p = 0.001), and 2.1 mm for the WasherLoc (p < 0.0001). The tensile force applied to a soft-tissue anterior cruciate ligament graft is not transferred intra-articularly and is not maintained during graft fixation. The loss in tension is caused by friction in the tibial tunnel and wrapping the graft around the shank of the screw of the spiked washer, insertion of the tibial fixation device, and cyclical loading of the knee. The amount of tension loss is sufficient to increase the maximal anterior translation.

  6. Application of Viscoelastic Fracture Model and Non-uniform Crack Initiation at Clinically Relevant Notches in Crosslinked UHMWPE

    PubMed Central

    Sirimamilla, P. Abhiram; Furmanski, Jevan; Rimnac, Clare M.

    2012-01-01

    The mechanism of crack initiation from a clinically relevant notch is not well-understood for crosslinked ultra high molecular weight polyethylene (UHMWPE) used in total joint replacement components. Static mode driving forces, rather than the cyclic mode conditions typically associated with fatigue processes, have been shown to drive crack propagation in this material. Thus, in this study, crack initiation in a notched specimen under a static load was investigated. A video microscope was used to monitor the notch surface of the specimen and crack initiation time was measured from the video by identifying the onset of crack initiation at the notch. Crack initiation was considered using a viscoelastic fracture theory. It was found that the mechanism of crack initiation involved both single layer and a distributed multi-layer phenomenon and that multi-layer crack initiation delayed the crack initiation time for all loading conditions examined. The findings of this study support that the viscoelastic fracture theory governs fracture mechanics in crosslinked UHMWPE. The findings also support that crack initiation from a notch in UHMWPE is a more complex phenomenon than treated by traditional fracture theories for polymers. PMID:23127638

  7. Nucleation and growth of apatite on NaOH-treated PEEK, HDPE and UHMWPE for artificial cornea materials.

    PubMed

    Pino, M; Stingelin, N; Tanner, K E

    2008-11-01

    The skirt of an artificial cornea must integrate the implant to the host sclera, a major failure of present devices. Thus, it is highly desirable to encourage the metabolic activity of the cornea by using more bioactive, flexible skirt materials. Here we describe attempts to increase the bioactivity of polyether ether ketone (PEEK), high-density polyethylene (HDPE) and ultra-high molecular weight polyethylene (UHMWPE) films. The effectiveness of different strength NaOH pre-treatments to initiate apatite deposition on PEEK, HDPE and UHMWPE is investigated. We find that exposure of PEEK, HDPE and UHMWPE films to NaOH solutions induces the formation of potential nuclei for apatite (calcium phosphate), from which the growth of an apatite coating is stimulated when subsequently immersing the polymer films in 1.5 strength Simulated Body Fluid (SBF). As immersion time in SBF increases, further nucleation and growth produces a thicker and more compact apatite coating that can be expected to be highly bioactive. Interestingly, the apatite growth is found to also be dependent on both the concentration of NaOH solution and the structure of the polymer surface.

  8. Tibial plateau fracture following gracilis-semitendinosus anterior cruciate ligament reconstruction: The tibial tunnel stress-riser.

    PubMed

    Sundaram, R O; Cohen, D; Barton-Hanson, N

    2006-06-01

    Tibial plateau fractures following anterior cruciate ligament (ACL) reconstruction are extremely rare. This is the first reported case of a tibial plateau fracture following four-strand gracilis-semitendinosus autograft ACL reconstruction. The tibial tunnel alone may behave as a stress riser which can significantly reduce bone strength.

  9. Mechanical properties of HDPE/UHMWPE blends: effect of filler loading and filler treatment.

    PubMed

    Lai, K L K; Roziyanna, A; Ogunniyi, D S; Zainal, Arifin M I; Azlan, Ariffin A

    2004-05-01

    Various blend ratios of high-density polyethylene (HDPE) and ultra high molecular weight polyethylene (UHMWPE) were prepared with the objective of determining their suitability as biomaterials. In the unfilled state, a blend of 50/50 (HDPE/UHMWPE) ratio by weight was found to yield optimum properties in terms of processability and mechanical properties. Hydroxyapatite (HA) was compounded with the optimum blend ratio. The effects of HA loading, varied from 0 to 50wt% for both filled and unfilled blends were tested for mechanical properties. It was found that the inclusion of HA in the blend led to a remarkable improvement of mechanical properties compared to the unfilled blend. In order to improve the bonding between the polymer blend and the filler, the HA used was chemically treated with a coupling agent known as 3-(trimethoxysiyl) propyl methacrylate and the treated HA was mixed into the blend. The effect of mixing the blend with silane-treated HA also led to an overall improvement of mechanical properties.

  10. Tibial Tray Thickness Significantly Increases Medial Tibial Bone Resorption in Cobalt-Chromium Total Knee Arthroplasty Implants.

    PubMed

    Martin, J Ryan; Watts, Chad D; Levy, Daniel L; Miner, Todd M; Springer, Bryan D; Kim, Raymond H

    2017-01-01

    Stress shielding is an uncommon complication associated with primary total knee arthroplasty. Patients are frequently identified radiographically with minimal clinical symptoms. Very few studies have evaluated risk factors for postoperative medial tibial bone loss. We hypothesized that thicker cobalt-chromium tibial trays are associated with increased bone loss. We performed a retrospective review of 100 posterior stabilized, fixed-bearing total knee arthroplasty where 50 patients had a 4-mm-thick tibial tray (thick tray cohort) and 50 patients had a 2.7-mm-thick tibial tray (thin tray cohort). A clinical evaluation and a radiographic assessment of medial tibial bone loss were performed on both cohorts at a minimum of 2 years postoperatively. Mean medial tibial bone loss was significantly higher in the thick tray cohort (1.07 vs 0.16 mm; P = .0001). In addition, there were significantly more patients with medial tibial bone loss in the thick tray group compared with the thin tray group (44% vs 10%, P = .0002). Despite these differences, there were no statistically significant differences in range of motion, knee society score, complications, or revision surgeries performed. A thicker cobalt-chromium tray was associated with significantly more medial tibial bone loss. Despite these radiographic findings, we found no discernable differences in clinical outcomes in our patient cohort. Further study and longer follow-up are needed to understand the effects and clinical significance of medial tibial bone loss. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Fatigue crack propagation behavior of ultrahigh molecular weight polyethylene.

    PubMed

    Connelly, G M; Rimnac, C M; Wright, T M; Hertzberg, R W; Manson, J A

    1984-01-01

    The relative fatigue crack propagation resistance of plain and carbon fiber-reinforced ultrahigh molecular weight polyethylene (UHMWPE) was determined from cyclic loading tests performed on compact tension specimens machined from the tibial components of total knee prostheses. Both materials were characterized by dynamic mechanical spectroscopy, X-ray diffraction, and differential scanning calorimetry. The cyclic tests used loading in laboratory air at 5 Hz using a sinusoidal wave form. Dynamic mechanical spectroscopy showed that the reinforced UHMWPE had a higher elastic storage modulus than the plain UHMWPE, whereas X-ray diffraction and differential scanning calorimetry showed that the percent crystallinity and degree of order in the crystalline regions were similar for the two materials. Fatigue crack propagation in both materials proved to be very sensitive to small changes in the applied cyclic stress intensity range. A 10% increase in stress intensity resulted in approximately an order of magnitude increase in fatigue crack growth rate. The fatigue crack propagation resistance of the reinforced UHMWPE was found to be significantly worse than that of the plain UHMWPE. This result was attributed to poor bonding between the carbon fibers and the UHMWPE matrix and the ductile nature of the matrix itself.

  12. Cranial tibial wedge osteotomy: a technique for eliminating cranial tibial thrust in cranial cruciate ligament repair.

    PubMed

    Slocum, B; Devine, T

    1984-03-01

    Cranial tibial wedge osteotomy, surgical technique for cranial cruciate ligament rupture, was performed on 19 stifles in dogs. This procedure leveled the tibial plateau, thus causing weight-bearing forces to be compressive and eliminating cranial tibial thrust. Without cranial tibial thrust, which was antagonistic to the cranial cruciate ligament and its surgical reconstruction, cruciate ligament repairs were allowed to heal without constant loads. This technique was meant to be used as an adjunct to other cranial cruciate ligament repair techniques.

  13. Accelerated aging studies of UHMWPE. I. Effect of resin, processing, and radiation environment on resistance to mechanical degradation.

    PubMed

    Edidin, A A; Herr, M P; Villarraga, M L; Muth, J; Yau, S S; Kurtz, S M

    2002-08-01

    The resin and processing route have been identified as potential variables influencing the mechanical behavior, and hence the clinical performance, of ultra-high molecular weight polyethylene (UHMWPE) orthopedic components. Researchers have reported that components fabricated from 1900 resin may oxidize to a lesser extent than components fabricated from GUR resin during shelf aging after gamma sterilization in air. Conflicting reports on the oxidation resistance for 1900 raise the question of whether resin or manufacturing method, or an interaction between resin and manufacturing method, influences the mechanical behavior of UHMWPE. We conducted a series of accelerated aging studies (no aging, aging in oxygen or in nitrogen) to systematically examine the influence of resin (GUR or 1900), manufacturing method (bulk compression molding or extrusion), and sterilization method (none, in air, or in nitrogen) on the mechanical behavior of UHMWPE. The small punch testing technique was used to evaluate the mechanical behavior of the materials, and Fourier transform infrared spectroscopy was used to characterize the oxidation in selected samples. Our study showed that the sterilization environment, aging condition, and specimen location (surface or subsurface) significantly affected the mechanical behavior of UHMWPE. Each of the three polyethylenes evaluated seem to degrade according to a similar pathway after artificial aging in oxygen and gamma irradiation in air. The initial ability of the materials to exhibit post-yield strain hardening was significantly compromised by degradation. In general, there were only minor differences in the aging behavior of molded and extruded GUR 1050, whereas the molded 1900 material seemed to degrade slightly faster than either of the 1050 materials. Copyright 2002 Wiley Periodicals, Inc.

  14. Modifying friction between ultra-high molecular weight polyethylene (UHMWPE) yarns with plasma enhanced chemical vapour deposition (PCVD)

    NASA Astrophysics Data System (ADS)

    Chu, Yanyan; Chen, Xiaogang; Tian, Lipeng

    2017-06-01

    Ultra-high molecular weight polyethylene (UHMWPE) yarns are widely used in military applications for protection owing to its high modulus and high strength; however, the friction between UHMWPE yarns is too small, which is a weakness for ballistic applications. The purpose of current research is to increase the friction between UHMWPE yarns by plasma enhanced chemical vapour deposition (PCVD). The changes of morphology and chemical structure were characterised by SEM and FTIR individually. The coefficients of friction between yarns were tested by means of Capstan method. Results from tests showed that the yarn-yarn coefficient of static friction (CSF) has been improved from 0.12 to 0.23 and that of kinetic friction (CSF) increased from 0.11 to 0.19, as the samples exposure from 21 s to 4 min. The more inter-yarn friction can be attributed to more and more particles and more polar groups deposited on the surfaces of yarns, including carboxyl, carbonyl, hydroxyl and amine groups and compounds containing silicon. The tensile strength and modulus of yarns, which are essential to ballistic performance, keep stable and are not affected by the treatments, indicating that PCVD treatment is an effective way to improve the inter-yarn friction without mechanical property degradation.

  15. Effect of Tibial Plateau Levelling Osteotomy on Cranial Tibial Subluxation in the Feline Cranial Cruciate Deficient Stifle Joint: An Ex Vivo Experimental Study.

    PubMed

    Bilmont, A; Retournard, M; Asimus, E; Palierne, S; Autefage, A

    2018-06-11

     This study evaluated the effects of tibial plateau levelling osteotomy on cranial tibial subluxation and tibial rotation angle in a model of feline cranial cruciate ligament deficient stifle joint.  Quadriceps and gastrocnemius muscles were simulated with cables, turnbuckles and a spring in an ex vivo limb model. Cranial tibial subluxation and tibial rotation angle were measured radiographically before and after cranial cruciate ligament section, and after tibial plateau levelling osteotomy, at postoperative tibial plateau angles of +5°, 0° and -5°.  Cranial tibial subluxation and tibial rotation angle were not significantly altered after tibial plateau levelling osteotomy with a tibial plateau angle of +5°. Additional rotation of the tibial plateau to a tibial plateau angle of 0° and -5° had no significant effect on cranial tibial subluxation and tibial rotation angle, although 2 out of 10 specimens were stabilized by a postoperative tibial plateau angle of -5°. No stabilization of the cranial cruciate ligament deficient stifle was observed in this model of the feline stifle, after tibial plateau levelling osteotomy.  Given that stabilization of the cranial cruciate ligament deficient stifle was not obtained in this model, simple transposition of the tibial plateau levelling osteotomy technique from the dog to the cat may not be appropriate. Schattauer GmbH Stuttgart.

  16. The Valgus Inclination of the Tibial Component Increases the Risk of Medial Tibial Condylar Fractures in Unicompartmental Knee Arthroplasty.

    PubMed

    Inoue, Shinji; Akagi, Masao; Asada, Shigeki; Mori, Shigeshi; Zaima, Hironori; Hashida, Masahiko

    2016-09-01

    Medial tibial condylar fractures (MTCFs) are a rare but serious complication after unicompartmental knee arthroplasty. Although some surgical pitfalls have been reported for MTCFs, it is not clear whether the varus/valgus tibial inclination contributes to the risk of MTCFs. We constructed a 3-dimensional finite elemental method model of the tibia with a medial component and assessed stress concentrations by changing the inclination from 6° varus to 6° valgus. Subsequently, we repeated the same procedure adding extended sagittal bone cuts of 2° and 10° in the posterior tibial cortex. Furthermore, we calculated the bone volume that supported the tibial component, which is considered to affect stress distribution in the medial tibial condyle. Stress concentrations were observed on the medial tibial metaphyseal cortices and on the anterior and posterior tibial cortices in the corner of cut surfaces in all models; moreover, the maximum principal stresses on the posterior cortex were larger than those on the anterior cortex. The extended sagittal bone cuts in the posterior tibial cortex increased the stresses further at these 3 sites. In the models with a 10° extended sagittal bone cut, the maximum principal stress on the posterior cortex increased as the tibial inclination changed from 6° varus to 6° valgus. The bone volume decreased as the inclination changed from varus to valgus. In this finite element method, the risk of MTCFs increases with increasing valgus inclination of the tibial component and with increased extension of the sagittal cut in the posterior tibial cortex. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Evaluation of stability of osteosynthesis with K-wires on an artificial model of tibial malleolus fracture.

    PubMed

    Bumči, Igor; Vlahović, Tomislav; Jurić, Filip; Žganjer, Mirko; Miličić, Gordana; Wolf, Hinko; Antabak, Anko

    2015-11-01

    Paediatric ankle fractures comprise approximately 4% of all paediatric fractures and 30% of all epiphyseal fractures. Integrity of the ankle "mortise", which consists of tibial and fibular malleoli, is significant for stability and function of the ankle joint. Tibial malleolar fractures are classified as SH III or SH IV intra-articular fractures and, in cases where the fragments are displaced, anatomic reposition and fixation is mandatory. Type SH III-IV fractures of the tibial malleolus are usually treated with open reduction and fixation with cannulated screws that are parallel to the physis. Two K-wires are used for temporary stabilisation of fragments during reduction. A third "guide wire" for the screw is then placed parallel with the physis. Considering the rules of mechanics, it is assumed that the two temporary pins with the additional third pin placed parallel to the physis create a strong triangle and thus provide strong fracture fixation. To prove this hypothesis, an experiment was conducted on the artificial models of the lower end of the tibia from the company "Sawbones". Each model had been sawn in a way that imitates the fracture of medial malleoli and then reattached with 1.8mm pins in various combinations. Prepared models were then tested for tensile and pressure forces. The least stable model was that in which the fractured pieces were attached with only two parallel pins. The most stable model comprised three pins, where two crossed pins were inserted in the opposite compact bone and the third pin was inserted through the epiphysis parallel with and below the growth plate. A potential method of choice for fixation of tibial malleolar fractures comprises three K-wires, where two crossed pins are placed in the opposite compact bone and one is parallel with the growth plate. The benefits associated with this method include shorter operating times and avoidance of a second operation for screw removal. Copyright © 2015 Elsevier Ltd. All rights

  18. Anatomic tibial component design can increase tibial coverage and rotational alignment accuracy: a comparison of six contemporary designs.

    PubMed

    Dai, Yifei; Scuderi, Giles R; Bischoff, Jeffrey E; Bertin, Kim; Tarabichi, Samih; Rajgopal, Ashok

    2014-12-01

    The aim of this study was to comprehensively evaluate contemporary tibial component designs against global tibial anatomy. We hypothesized that anatomically designed tibial components offer increased morphological fit to the resected proximal tibia with increased alignment accuracy compared to symmetric and asymmetric designs. Using a multi-ethnic bone dataset, six contemporary tibial component designs were investigated, including anatomic, asymmetric, and symmetric design types. Investigations included (1) measurement of component conformity to the resected tibia using a comprehensive set of size and shape metrics; (2) assessment of component coverage on the resected tibia while ensuring clinically acceptable levels of rotation and overhang; and (3) evaluation of the incidence and severity of component downsizing due to adherence to rotational alignment and overhang requirements, and the associated compromise in tibial coverage. Differences in coverage were statistically compared across designs and ethnicities, as well as between placements with or without enforcement of proper rotational alignment. Compared to non-anatomic designs investigated, the anatomic design exhibited better conformity to resected tibial morphology in size and shape, higher tibial coverage (92% compared to 85-87%), more cortical support (posteromedial region), lower incidence of downsizing (3% compared to 39-60%), and less compromise of tibial coverage (0.5% compared to 4-6%) when enforcing proper rotational alignment. The anatomic design demonstrated meaningful increase in tibial coverage with accurate rotational alignment compared to symmetric and asymmetric designs, suggesting its potential for less intra-operative compromises and improved performance. III.

  19. Effects of directly autotransplanted tibial bone marrow aspirates on bone regeneration and osseointegration of dental implants.

    PubMed

    Payer, Michael; Lohberger, Birgit; Strunk, Dirk; Reich, Karoline M; Acham, Stephan; Jakse, Norbert

    2014-04-01

    Aim of the pilot trial was to evaluate applicability and effects of directly autotransplanted tibial bone marrow (BM) aspirates on the incorporation of porous bovine bone mineral in a sinus lift model and on the osseointegration of dental implants. Six edentulous patients with bilaterally severely resorbed maxillae requiring sinus augmentation and implant treatment were included. During surgery, tibial BM was harvested and added to bone substitute material (Bio-Oss(®) ) at the randomly selected test site. At control sites, augmentation was performed with Bio-Oss(®) alone. The cellular content of each BM aspirate was checked for multipotency and surface antigen expression as quality control. Histomorphometric analysis of biopsies from the augmented sites after 3 and 6 months (during implantation) was used to evaluate effects on bone regeneration. Osseointegration of implants was evaluated with Periotest(®) and radiographic means. Multipotent cellular content in tibial BM aspirates was comparable to that in punctures from the iliac crest. No significant difference in amount of new bone formation and the integration of bone substitute particles was detected histomorphometrically. Periotest(®) values and radiographs showed successful osseointegration of inserted implants at all sites. Directly autotransplanted tibial BM aspirates did not show beneficial regenerative effects in the small study population (N = 6) of the present pilot trial. However, the proximal tibia proved to be a potential donor site for small quantities of BM. Future trials should clarify whether concentration of tibial BM aspirates could effect higher regenerative potency. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. [Tibial periostitis ("medial tibial stress syndrome")].

    PubMed

    Fournier, Pierre-Etienne

    2003-06-01

    Medial tibial stress syndrome is characterised by complaints along the posteromedial tibia. Runners and athletes involved in jumping activities may develop this syndrome. Increased stress to stabilize the foot especially when excessive pronation is present explain the occurrence this lesion.

  1. A Randomized Cadaver Study Comparing First-Attempt Success Between Tibial and Humeral Intraosseous Insertions Using NIO Device by Paramedics: A Preliminary Investigation.

    PubMed

    Szarpak, Lukasz; Truszewski, Zenon; Smereka, Jacek; Krajewski, Paweł; Fudalej, Marcin; Adamczyk, Piotr; Czyzewski, Lukasz

    2016-05-01

    Medical personnel may encounter difficulties in obtaining intravenous (IV) access during cardiac arrest. The 2015 American Heart Association guidelines and the 2015 European Resuscitation Council guidelines for cardiopulmonary resuscitation (CPR) suggest that rescuers establish intraosseous (IO) access if an IV line is not easily obtainable.The aim of the study was to compare the success rates of the IO proximal tibia and proximal humerus head access performed by paramedics using the New Intraosseous access device (NIO; Persys Medical, Houston, TX, USA) in an adult cadaver model during simulated CPR.In an interventional, randomized, crossover, single-center cadaver study, a semi-automatic spring-load driven NIO access device was investigated. In total, 84 paramedics with less than 5-year experience in Emergency Medical Service participated in the study. The trial was performed on 42 adult cadavers. In each cadaver, 2 IO accesses to the humerus head, and 2 IO accesses to the proximal tibia were obtained.The success rate of the first IO attempt was 89.3% (75/84) for tibial access, and 73.8% (62/84) for humeral access (P = 0.017). The procedure times were significantly faster for tibial access [16.8 (interquartile range, IQR, 15.1-19.9] s] than humeral access [26.7 (IQR, 22.1-30.9) s] (P < 0.001).Tibial IO access is easier and faster to put in place than humeral IO access. Humeral IO access can be an alternative method to tibial IO access. clinicaltrials.gov Identifier: NCT02700867.

  2. Effects of Loading Duration and Short Rest Insertion on Cancellous and Cortical Bone Adaptation in the Mouse Tibia

    PubMed Central

    Yang, Haisheng; Embry, Rachel E.; Main, Russell P.

    2017-01-01

    The skeleton’s osteogenic response to mechanical loading can be affected by loading duration and rest insertion during a series of loading events. Prior animal loading studies have shown that the cortical bone response saturates quickly and short rest insertions between load cycles can enhance cortical bone formation. However, it remains unknown how loading duration and short rest insertion affect load-induced osteogenesis in the mouse tibial compressive loading model, and particularly in cancellous bone. To address this issue, we applied cyclic loading (-9 N peak load; 4 Hz) to the tibiae of three groups of 16 week-old female C57BL/6 mice for two weeks, with a different number of continuous load cycles applied daily to each group (36, 216 and 1200). A fourth group was loaded under 216 daily load cycles with a 10 s rest insertion after every fourth cycle. We found that as few as 36 load cycles per day were able to induce osteogenic responses in both cancellous and cortical bone. Furthermore, while cortical bone area and thickness continued to increase through 1200 cycles, the incremental increase in the osteogenic response decreased as load number increased, indicating a reduced benefit of the increasing number of load cycles. In the proximal metaphyseal cancellous bone, trabecular thickness increased with load up to 216 cycles. We also found that insertion of a 10 s rest between load cycles did not improve the osteogenic response of the cortical or cancellous tissues compared to continuous loading in this model given the age and sex of the mice and the loading parameters used here. These results suggest that relatively few load cycles (e.g. 36) are sufficient to induce osteogenic responses in both cortical and cancellous bone in the mouse tibial loading model. Mechanistic studies using the mouse tibial loading model to examine bone formation and skeletal mechanobiology could be accomplished with relatively few load cycles. PMID:28076363

  3. Arthroscopic Management of Tibial Spine Avulsion Fractures: Principles and Techniques.

    PubMed

    Strauss, Eric J; Kaplan, Daniel James; Weinberg, Maxwell E; Egol, Jonathan; Jazrawi, Laith M

    2018-05-15

    Tibial spine fractures are uncommon injuries affecting the insertion of the anterior cruciate ligament on the tibia. They typically occur in skeletally immature patients aged 8 to 14 years and result from hyperextension of the knee with a valgus or rotational force. Diagnosis is based on history, physical examination, and standard radiographs. The use of MRI can identify entrapped soft tissue that may prevent reduction. Open or arthroscopic repair is indicated in patients with partially displaced fractures (>5 mm) with one third to one half of the avulsed fragment elevated, in patients who have undergone unsuccessful nonsurgical reduction and long leg casting or bracing, and in patients with completely displaced fractures. Arthroscopy offers reduced invasiveness and decreased morbidity. Suture fixation and screw fixation have produced successful results. Suture fixation can eliminate the risk of fracture fragment comminution during screw insertion, the risk of neurovascular injury, and the need for hardware removal. Suture fixation is ideal in cases in which existing comminution prevents screw fixation.

  4. Indirect reduction technique using a distraction support in minimally invasive percutaneous plate osteosynthesis of tibial shaft fractures.

    PubMed

    Dong, Wen-Wei; Shi, Zeng-Yuan; Liu, Zheng-Xin; Mao, Hai-Jiao

    2016-12-01

    To describe an indirect reduction technique during minimally invasive percutaneous plate osteosynthesis (MIPPO) of tibial shaft fractures with the use of a distraction support. Between March 2011 and October 2014, 52 patients with a mean age of 48 years (16-72 years) sustaining tibial shaft fractures were included. All the patients underwent MIPPO for the fractures using a distraction support prior to insertion of the plate. Fracture angular deformity was assessed by goni- ometer measurement on preoperative and postoperative images. Preoperative radiographs revealed a mean of 7.6°(1.2°-28°) angulation in coronal plane and a mean of 6.8°(0.5°-19°) angulation in sagittal plane. Postoperative anteroposterior and lateral radio- graphs showed a mean of 0.8°(0°-4.0°) and 0.6°(0°-3.6°) of varus/valgus and apex anterior/posterior angulation, respectively. No intraoperative or postoperative complications were noted. This study suggests that the distraction support during MIPPO of tibial shaft fractures is an effective and safe method with no associated complications.

  5. An activated energy approach for accelerated testing of the deformation of UHMWPE in artificial joints.

    PubMed

    Galetz, Mathias Christian; Glatzel, Uwe

    2010-05-01

    The deformation behavior of ultrahigh molecular polyethylene (UHMWPE) is studied in the temperature range of 23-80 degrees C. Samples are examined in quasi-static compression, tensile and creep tests to determine the accelerated deformation of UHMWPE at elevated temperatures. The deformation mechanisms under compression load can be described by one strain rate and temperature dependent Eyring process. The activation energy and volume of that process do not change between 23 degrees C and 50 degrees C. This suggests that the deformation mechanism under compression remains stable within this temperature range. Tribological tests are conducted to transfer this activated energy approach to the deformation behavior under loading typical for artificial knee joints. While this approach does not cover the wear mechanisms close to the surface, testing at higher temperatures is shown to have a significant potential to reduce the testing time for lifetime predictions in terms of the macroscopic creep and deformation behavior of artificial joints. Copyright 2010. Published by Elsevier Ltd.

  6. [Application of tibial mechanical axis locator in tibial extra-articular deformity in total knee arthroplasty].

    PubMed

    Li, Guoliang; Han, Guangpu; Zhang, Jinxiu; Ma, Shiqiang; Guo, Donghui; Yuan, Fulu; Qi, Bingbing; Shen, Runbin

    2013-07-01

    To explore the application value of self-made tibial mechanical axis locator in tibial extra-articular deformity in total knee arthroplasty (TKA) for improving the lower extremity force line. Between January and August 2012, 13 cases (21 knees) of osteoarthritis with tibial extra-articular deformity were treated, including 5 males (8 knees) and 8 females (13 knees) with an average age of 66.5 years (range, 58-78 years). The disease duration was 2-5 years (mean, 3.5 years). The knee society score (KSS) was 45.5 +/- 15.5. Extra-articular deformities included 1 case of knee valgus (2 knees) and 12 cases of knee varus (19 knees). Preoperative full-length X-ray films of lower extremities showed 10-21 degrees valgus or varus deformity of tibial extra joint. Self-made tibial mechanical axis locator was used to determine and mark coronal tibial mechanical axis under X-ray before TKA, and then osteotomy was performed with extramedullary positioning device according to the mechanical axis marker.' All incisions healed by first intention, without related complications of infection and joint instability. All patients were followed up 5-12 months (mean, 8.3 months). The X-ray examination showed < 2 degrees knee deviation angle in the others except 1 case of 2.9 degrees knee deviation angle at 3 days after operation, and the accurate rate was 95.2%. No loosening or instability of prosthesis occurred during follow-up. KSS score was 85.5 +/- 15.0 at last follow-up, showing significant difference when compared with preoperative score (t=12.82, P=0.00). The seft-made tibial mechanical axis locator can improve the accurate rate of the lower extremity force line in TKA for tibia extra-articular deformity.

  7. Preparation and characterization of CNTs/UHMWPE nanocomposites via a novel mixer under synergy of ultrasonic wave and extensional deformation.

    PubMed

    Yin, Xiaochun; Li, Sai; He, Guangjian; Feng, Yanhong; Wen, Jingsong

    2018-05-01

    In this work, design and development of a new melt mixing method and corresponding mixer for polymer materials were reported. Effects of ultrasonic power and sonication time on the carbon nanotubes (CNTs) filled ultra high molecular weight polyethylene (UHMWPE) nanocomposites were experimentally studied. Transmission Electron Microscopy images showed that homogeneous dispersion of CNTs in intractable UHMWPE matrix is successfully realized due to the synergetic effect of ultrasonic wave and extensional deformation without any aid of other additives or solvents. Differential scanning calorimetry results revealed an increase in crystallinity and crystallization rate due to the finer dispersion of the CNTs in the matrix which act as nucleating point. Composites' complex viscosity and storage modulus decreased sharply at first and then leveled off with the increase of sonication time or the ultrasonic power. The thermal stability and the tensile strength of the CNTs/UHMWPE nanocomposites improved by using this novel mixing method. This is the first method that combined the ultrasonic wave and the extensional deformation in which the elongation rate, sonication time and ultrasonic power can be adjusted simultaneously during mixing. The novel mixer offers several advantages such as environment-friendly, high mixing efficiency, self-cleaning and wide adaptability to materials. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Maximizing tibial coverage is detrimental to proper rotational alignment.

    PubMed

    Martin, Stacey; Saurez, Alex; Ismaily, Sabir; Ashfaq, Kashif; Noble, Philip; Incavo, Stephen J

    2014-01-01

    Traditionally, the placement of the tibial component in total knee arthroplasty (TKA) has focused on maximizing coverage of the tibial surface. However, the degree to which maximal coverage affects correct rotational placement of symmetric and asymmetric tibial components has not been well defined and might represent an implant design issue worthy of further inquiry. Using four commercially available tibial components (two symmetric, two asymmetric), we sought to determine (1) the overall amount of malrotation that would occur if components were placed for maximal tibial coverage; and (2) whether the asymmetric designs would result in less malrotation than the symmetric designs when placed for maximal coverage in a computer model using CT reconstructions. CT reconstructions of 30 tibial specimens were used to generate three-dimensional tibia reconstructions with attention to the tibial anatomic axis, the tibial tubercle, and the resected tibial surface. Using strict criteria, four commercially available tibial designs (two symmetric, two asymmetric) were placed on the resected tibial surface. The resulting component rotation was examined. Among all four designs, 70% of all tibial components placed in orientation maximizing fit to resection surface were internally malrotated (average 9°). The asymmetric designs had fewer cases of malrotation (28% and 52% for the two asymmetric designs, 100% and 96% for the two symmetric designs; p < 0.001) and less malrotation on average (2° and 5° for the asymmetric designs, 14° for both symmetric designs; p < 0.001). Maximizing tibial coverage resulted in implant malrotation in a large percentage of cases. Given similar amounts of tibial coverage, correct rotational positioning was more likely to occur with the asymmetric designs. Malrotation of components is an important cause of failure in TKA. Priority should be given to correct tibial rotational positioning. This study suggested that it is easier to balance rotation and

  9. Posterior tibial slope in medial opening-wedge high tibial osteotomy: 2-D versus 3-D navigation.

    PubMed

    Yim, Ji Hyeon; Seon, Jong Keun; Song, Eun Kyoo

    2012-10-01

    Although opening-wedge high tibial osteotomy (HTO) is used to correct deformities, it can simultaneously alter tibial slope in the sagittal plane because of the triangular configuration of the proximal tibia, and this undesired change in tibial slope can influence knee kinematics, stability, and joint contact pressure. Therefore, medial opening-wedge HTO is a technically demanding procedure despite the use of 2-dimensional (2-D) navigation. The authors evaluated the posterior tibial slope pre- and postoperatively in patients who underwent navigation-assisted opening-wedge HTO and compared posterior slope changes for 2-D and 3-dimensional (3-D) navigation versions. Patients were randomly divided into 2 groups based on the navigation system used: group A (2-D guidance for coronal alignment; 17 patients) and group B (3-D guidance for coronal and sagittal alignments; 17 patients). Postoperatively, the mechanical axis was corrected to a mean valgus of 2.81° (range, 1°-5.4°) in group A and 3.15° (range, 1.5°-5.6°) in group B. A significant intergroup difference existed for the amount of posterior tibial slope change (Δ slope) pre- and postoperatively (P=.04).Opening-wedge HTO using navigation offers accurate alignment of the lower limb. In particular, the use of 3-D navigation results in significantly less change in the posterior tibial slope postoperatively than does the use of 2-D navigation. Accordingly, the authors recommend the use of 3-D navigation systems because they provide real-time intraoperative information about coronal, sagittal, and transverse axes and guide the maintenance of the native posterior tibial slope. Copyright 2012, SLACK Incorporated.

  10. CoCrMo alloy vs. UHMWPE Particulate Implant Debris Induces Sex Dependent Aseptic Osteolysis Responses In Vivo using a Murine Model

    PubMed Central

    Landgraeber, Stefan; Samelko, Lauryn; McAllister, Kyron; Putz, Sebastian; Jacobs, Joshua.J.; Hallab, Nadim James

    2018-01-01

    Background: The rate of revision for some designs of total hip replacements due to idiopathic aseptic loosening has been reported as higher for women. However, whether this is environmental or inherently sex-related is not clear. Objective: Can particle induced osteolysis be sex dependent? And if so, is this dependent on the type of implant debris (e.g. metal vs polymer)? The objective of this study was to test for material dependent inflammatory osteolysis that may be linked to sex using CoCrMo and implant grade conventional polyethylene (UHMWPE), using an in vivo murine calvaria model. Methods: Healthy 12 week old female and male C57BL/6J mice were treated with UHMWPE (1.0um ECD) or CoCrMo particles (0.9um ECD) or received sham surgery. Bone resorption was assessed by micro-computed tomography, histology and histomorphometry on day 12 post challenge. Results: Female mice that received CoCrMo particles showed significantly more inflammatory osteolysis and bone destruction compared to the females who received UHMWPE implant debris. Moreover, females challenged with CoCrMo particles exhibited 120% more inflammatory bone loss compared to males (p<0.01) challenged with CoCrMo implant debris (but this was not the case for UHMWPE particles). Conclusion: We demonstrated sex-specific differences in the amount of osteolysis resulting from CoCrMo particle challenge. This suggests osteo-immune responses to metal debris are preferentially higher in female compared to male mice, and supports the contention that there may be inherent sex related susceptibility to some types of implant debris. PMID:29785221

  11. Incidence and epidemiology of tibial shaft fractures.

    PubMed

    Larsen, Peter; Elsoe, Rasmus; Hansen, Sandra Hope; Graven-Nielsen, Thomas; Laessoe, Uffe; Rasmussen, Sten

    2015-04-01

    The literature lacks recent population-based epidemiology studies of the incidence, trauma mechanism and fracture classification of tibial shaft fractures. The purpose of this study was to provide up-to-date information on the incidence of tibial shaft fractures in a large and complete population and report the distribution of fracture classification, trauma mechanism and patient baseline demographics. Retrospective reviews of clinical and radiological records. A total of 196 patients were treated for 198 tibial shaft fractures in the years 2009 and 2010. The mean age at time of fracture was 38.5 (21.2SD) years. The incidence of tibial shaft fracture was 16.9/100,000/year. Males have the highest incidence of 21.5/100,000/year and present with the highest frequency between the age of 10 and 20, whereas women have a frequency of 12.3/100,000/year and have the highest frequency between the age of 30 and 40. AO-type 42-A1 was the most common fracture type, representing 34% of all tibial shaft fractures. The majority of tibial shaft fractures occur during walking, indoor activity and sports. The distribution among genders shows that males present a higher frequency of fractures while participating in sports activities and walking. Women present the highest frequency of fractures while walking and during indoor activities. This study shows an incidence of 16.9/100,000/year for tibial shaft fractures. AO-type 42-A1 was the most common fracture type, representing 34% of all tibial shaft fractures. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Properties of crosslinked ultra-high-molecular-weight polyethylene.

    PubMed

    Lewis, G

    2001-02-01

    Substantially reducing the rate of generation of wear particles at the surfaces of ultra-high-molecular-weight polyethylene (UHMWPE) orthopedic implant bearing components, in vivo, is widely regarded as one of the most formidable challenges in modern arthroplasty. In the light of this, much research attention has been paid to the myriad of endogenous and exogenous factors that have been postulated to affect this wear rate, one such factor being the polymer itself. In recent years, there has been a resurgence of interest in crosslinking the polymer as a way of improving its properties that are considered relevant to its use for fabricating bearing components. Such properties include wear resistance, fatigue life, and fatigue crack propagation rate. Although a large volume of literature exists on the topic on the impact of crosslinking on the properties of UHMWPE, no critical appraisal of this literature has been published. This is one of the goals of the present article, which emphasizes three aspects. The first is the trade-off between improvement in wear resistance and depreciation in other mechanical and physical properties. The second aspect is the presentation of a method of estimating the optimal value of a crosslinking process variable (such as dose in radiation-induced crosslinking) that takes into account this trade-off. The third aspect is the description of a collection of under- and unexplored research areas in the field of crosslinked UHMWPE, such as the role of starting resin on the properties of the crosslinked polymer, and the in vitro evaluation of the wear rate of crosslinked tibial inserts and other bearing components that, in vivo, are subjected to nearly unidirectional motion.

  13. Pin on flat wear volume prediction of UHMWPE against cp Ti for orthopedic applications

    NASA Astrophysics Data System (ADS)

    Handoko, Suyitno, Dharmastiti, Rini; Magetsari, Rahadyan

    2018-04-01

    Tribological assessment of orthopedic biomaterials requires a lot of testing time. Researchers must test the biomaterials in millions of cycles at low frequency (1 Hz) to mimic the in vivo conditions. It is a problem because product designs and developments could not wait longer for wear data to predict the lifetime of their products. The problem can be solved with the use of computation techniques to model the wear phenomena and provide predicted data. The aim of this research is to predict the wear volume of the commonly used ultra high molecular weight polyethylene (UHMWPE) sliding against commercially pure titanium (cp Ti) in the unidirectional pin on flat tests. The 9 mm diameter UHMWPE pin and cp Ti plate contact mechanics were modeled using Abaqus. Contact pressure was set at 3 MPa. Outputs of the computations (contact pressure and contact area) were used to calculate the wear volume with Archard law. A custom Python script was made to automate the process. The results were then compared with experimental data for validations. The predicted data were in a good trend with numerical errors from 0.3% up to 26%.

  14. Characterization and tribology of PEG-like coatings on UHMWPE for total hip replacements.

    PubMed

    Kane, Sheryl R; Ashby, Paul D; Pruitt, Lisa A

    2010-03-15

    A crosslinked hydrogel coating similar to poly(ethylene glycol) (PEG) was covalently bonded to the surface of ultrahigh molecular weight polyethylene (UHMWPE) to improve the lubricity and wear resistance of the UHWMPE for use in total joint replacements. The chemistry, hydrophilicity, and protein adsorption resistance of the coatings were determined, and the wear behavior of the PEG-like coating was examined by two methods: pin-on-disk tribometry to evaluate macroscale behavior, and atomic force microscopy (AFM) to simulate asperity wear. As expected, the coating was found to be highly PEG-like, with approximately 83% ether content by x-ray photoelectron spectroscopy and more hydrophilic and resistant to protein adsorption than uncoated UHMWPE. Pin-on-disk testing showed that the PEG-like coating could survive 3 MPa of contact pressure, comparable to that experienced by total hip replacements. AFM nanoscratching experiments uncovered three damage mechanisms for the coatings: adhesion/microfracture, pure adhesion, and delamination. The latter two mechanisms appear to correlate well with wear patterns induced by pin-on-disk testing and evaluated by attenuated total reflection Fourier transform infrared spectroscopy mapping. Understanding the mechanisms by which the PEG-like coatings wear is critical for improving the behavior of subsequent generations of wear-resistant hydrogel coatings. (c) 2009 Wiley Periodicals, Inc.

  15. Increased revision rate with posterior tibial tunnel placement after using the 70-degree tibial guide in ACL reconstruction.

    PubMed

    Inderhaug, Eivind; Raknes, Sveinung; Østvold, Thomas; Solheim, Eirik; Strand, Torbjørn

    2017-01-01

    To map knee morphology radiographically in a population with a torn ACL and to investigate whether anatomic factors could be related to outcomes after ACL reconstruction at mid- to long-term follow-up. Further, we wanted to assess tibial tunnel placement after using the 70-degree "anti-impingement" tibial tunnel guide and investigate any relation between tunnel placement and revision surgery. Patients undergoing ACL reconstruction involving the 70-degree tibial guide from 2003 to 2008 were included. Two independent investigators analysed pre- and post-operative radiographs. Demographic data and information on revision surgery were collected from an internal database. Anatomic factors and post-operative tibial tunnel placements were investigated as predictors of revision. Three-hundred and seventy-seven patients were included in the study. A large anatomic variation with significant differences between men and women was seen. None of the anatomic factors could be related to a significant increase in revision rate. Patients with a posterior tibial tunnel placement, defined as 50 % or more posterior on the Amis and Jakob line, did, however, have a higher risk of revision surgery compared to patients with an anterior tunnel placement (P = 0.03). Use of the 70-degree tibial guide did result in a high incidence (47 %) of posterior tibial tunnel placements associated with an increased rate of revision surgery. The current study was, however, not able to identify any anatomic variation that could be related to a higher risk of revision surgery. Avoiding graft impingement from the femoral roof in anterior tibial tunnel placements is important, but the insight that overly posterior tunnel placement can lead to inferior outcome should also be kept in mind when performing ACL surgery. IV.

  16. Nondestructive characterization of UHMWPE armor materials

    NASA Astrophysics Data System (ADS)

    Chiou, Chien-Ping; Margetan, Frank J.; Barnard, Daniel J.; Hsu, David K.; Jensen, Terrence; Eisenmann, David

    2012-05-01

    Ultra-high molecular weight polyethylene (UHMWPE) is a material increasingly used for fabricating helmet and body armor. In this work, plate specimens consolidated from thin fiber sheets in series 3124 and 3130 were examined with ultrasound, X-ray and terahertz radiation. Ultrasonic through-transmission scans using both air-coupled and immersion modes revealed that the 3130 series material generally had much lower attenuation than the 3124 series, and that certain 3124 plates had extremely high attenuation. Due to the relatively low inspection frequencies used, pulse-echo immersion ultrasonic testing could not detect distinct flaw echoes from the interior. To characterize the nature of the defective condition that was responsible for the high ultrasonic attenuation, terahertz radiation in the time-domain spectroscopy mode were used to image the flaws. Terahertz scan images obtained on the high attenuation samples clearly showed a distribution of a large number of defects, possibly small planar delaminations, throughout the volume of the interior. Their precise nature and morphology are to be verified by optical microscopy of the sectioned surface.

  17. Fractures of the Tibial Plateau Involve Similar Energies as the Tibial Pilon but Greater Articular Surface Involvement

    PubMed Central

    Dibbern, Kevin; Kempton, Laurence B.; Higgins, Thomas F.; Morshed, Saam; McKinley, Todd O.; Marsh, J. Lawrence; Anderson, Donald D.

    2016-01-01

    Patients with tibial pilon fractures have a higher incidence of post-traumatic osteoarthritis than those with fractures of the tibial plateau. This may indicate that pilon fractures present a greater mechanical insult to the joint than do plateau fractures. We tested the hypothesis that fracture energy and articular fracture edge length, two independent indicators of severity, are higher in pilon than plateau fractures. We also evaluated if clinical fracture classification systems accurately reflect severity. Seventy-five tibial plateau fractures and fifty-two tibial pilon fractures from a multi-institutional study were selected to span the spectrum of severity. Fracture severity measures were calculated using objective CT-based image analysis methods. The ranges of fracture energies measured for tibial plateau and pilon fractures were 3.2 to 33.2 Joules (J) and 3.6 to 32.2 J, respectively, and articular fracture edge lengths were 68.0 to 493.0 mm and 56.1 to 288.6 mm, respectively. There were no differences in the fracture energies between the two fracture types, but plateau fractures had greater articular fracture edge lengths (p<0.001). The clinical fracture classifications generally reflected severity, but there was substantial overlap of fracture severity measures between different classes. Clinical Significance Similar fracture energies with different degrees of articular surface involvement suggest a possible explanation for dissimilar rates of post-traumatic osteoarthritis for fractures of the tibial plateau compared to the tibial pilon. The substantial overlap of severity measures between different fracture classes may well have confounded prior clinical studies relying on fracture classification as a surrogate for severity. PMID:27381653

  18. Trifurcation of the tibial nerve within the tarsal tunnel.

    PubMed

    Develi, Sedat

    2018-05-01

    The tibial nerve is the larger terminal branch of the sciatic nerve and it terminates in the tarsal tunnel by giving lateral and medial plantar nerves. We present a rare case of trifurcation of the tibial nerve within the tarsal tunnel. The variant nerve curves laterally after branching from the tibial nerve and courses deep to quadratus plantae muscle. Interestingly, posterior tibial artery was also terminating by giving three branches. These branches were accompanying the terminal branches of the tibial nerve.

  19. Intermediate term follow-up of calcaneal osteotomy and flexor digitorum longus transfer for treatment of posterior tibial tendon dysfunction.

    PubMed

    Fayazi, Amir H; Nguyen, Hoan-Vu; Juliano, Paul J

    2002-12-01

    Twenty-three patients with stage II posterior tibial tendon dysfunction who had failed non-surgical therapy were treated with flexor digitorum longus transfer and calcaneal osteotomy. At latest follow-up averaging 35 +/- 7 months (range, 24 to 51 months), 22 patients (96%) were subjectively "better" or "much better." No patient had difficulty with shoe wear; however, four patients (17%) required routine orthotic use consisting of a molded shoe insert. AOFAS scores were available on 21 patients and improved from a preoperative mean of 50 +/- 14 (range, 27 to 85) to a postoperative mean of 89 +/- 10 (range, 70 to 100). Our experience, at an intermediate date follow-up is that calcaneal osteotomy and flexor digitorum longus transfer is a safe and effective form of treatment for stage II posterior tibial tendon dysfunction.

  20. The Direct Insertion of the ACL Carries More Load than the Indirect Insertion

    PubMed Central

    Nawabi, Danyal H.; Tucker, Scott; Jones, Kristofer J.; Nguyen, Joseph; Wickiewicz, Thomas L.; Imhauser, Carl; Pearle, Andrew

    2014-01-01

    assessed under a blinded validation by experienced observers (TW, AP) who excluded two specimens that did not conform to the objective definitions of the sectioning method. Statistics: Loads were compared between direct and indirect locations at different flexion angles by conducting two-way repeated measures ANOVA models. Results: Under an anterior tibial load at 30o flexion, the direct insertion carried 83.9% (±7.2%) of the total ACL load compared to 16.1% (±7.2%) in the indirect insertion (p<0.001). The direct insertion also carried more load at 90o flexion (95.2% vs 4.8%; p<0.001). Under a combined rotatory load at 15o flexion, the direct insertion carried 84.2% (±4.2%)of the total ACL load compared to 15.8% (±4.2%) in the indirect insertion (p<0.001). Conclusion: The fibres in the direct insertion of the ACL carry more load than fibres in the indirect insertion. Previous studies have suggested that the direct insertion plays a major role in the mechanical link between the ACL and bone. With the current shift in emphasis towards anatomic ACL reconstruction, it may be beneficial to create the femoral tunnel within the direct insertion rather than ‘lower’ in the notch. Although further work is required in determining graft behaviour at the new insertions sites described in this study, our findings suggest that placing a graft in the region of the direct insertion may be an important consideration when adhering to the principles of anatomic ACL reconstruction.

  1. A questionnaire survey of the effect of different interface types on patient satisfaction and perceived problems among trans-tibial amputees.

    PubMed

    Van de Weg, F B; Van der Windt, D A W M

    2005-12-01

    The objectives were to investigate the effect of three different interface types on consumer satisfaction and perceived problems among trans-tibial amputees in the Netherlands. A postal questionnaire (based on the Prosthesis Evaluation Questionnaire) was sent to 353 patients. Responders were classified in three groups of interface types: polyethylene foam (PEF) inserts, silicone liners (SIL), and polyurethane liners (PUL). Differences concerning satisfaction and problems between interface types were computed and adjusted for potential confounding by age, gender, reason for amputation and time since first prosthesis. A total of 220 patients responded (62%). Patients wearing liners reported a significantly poorer durability and higher maintenance time compared with patients using PEF inserts. Sum-scores for satisfaction or problems did not show any significant differences between groups. Analysis of individual items showed a significant difference only for satisfaction with sitting and with walking on uneven terrain in favour of PEF inserts. In contrast to most studies, interface type was included as a possible determinant of customer use, satisfaction, and perceived problems. The perceived differences between the three suspension types are to a large extent small and non-significant. The findings do not support liner prescription as a matter of course for all trans-tibial amputees. A careful analysis of patients' preferences should be made to determine the best course of action. Further studies, preferably prospective, need to be conducted to determine which systems are most comfortable and offer least complaints.

  2. Tibial Lengthening: Extraarticular Calcaneotibial Screw to Prevent Ankle Equinus

    PubMed Central

    Belthur, Mohan V.; Paley, Dror; Jindal, Gaurav; Burghardt, Rolf D.; Specht, Stacy C.

    2008-01-01

    Between 2003 and 2006, we used an extraarticular, cannulated, fully threaded posterior calcaneotibial screw to prevent equinus contracture in 10 patients (four male and six female patients, 14 limbs) undergoing tibial lengthening with the intramedullary skeletal kinetic distractor. Diagnoses were fibular hemimelia (two), mesomelic dwarfism (two), posteromedial bow (one), hemihypertrophy (one), poliomyelitis (one), achondroplasia (one), posttraumatic limb-length discrepancy (one), and hypochondroplasia (one). Average age was 24.5 years (range, 15–54 years). The screw (length, typically 125 mm; diameter, 7 mm) was inserted with the ankle in 10° dorsiflexion. Gastrocnemius soleus recession was performed in two patients to achieve 10° dorsiflexion. Average lengthening was 4.9 cm (range, 3–7 cm). Screws were removed after a mean 3.3 months (range, 2–6 months). Preoperative ankle range of motion was regained within 6 months of screw removal. No neurovascular complications were encountered, and no patients experienced equinus contracture. We also conducted a cadaveric study in which one surgeon inserted screws in eight cadaveric legs under image intensifier control. The flexor hallucis longus muscle belly was the closest anatomic structure noted during dissection. The screw should be inserted obliquely from upper lateral edge of the calcaneus and aimed lateral in the tibia to avoid the flexor hallucis longus muscle. Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18800215

  3. Do modern total knee replacements improve tibial coverage?

    PubMed

    Meier, Malin; Webb, Jonathan; Collins, Jamie E; Beckmann, Johannes; Fitz, Wolfgang

    2018-01-25

    The purpose of the present study is to compare newer designs of various symmetric and asymmetric tibial components and measure tibial bone coverage using the rotational safe zone defined by two commonly utilized anatomic rotational landmarks. Computed tomography scans (CT scans) of one hundred consecutive patients scheduled for total knee arthroplasty were obtained pre-operatively. A virtual proximal tibial cut was performed and two commonly used rotational axes were added for each image: the medio-lateral axis (ML-axis) and the medial 1/3 tibial tubercle axis (med-1/3-axis). Different symmetric and asymmetric implant designs were then superimposed in various rotational positions for best cancellous and cortical coverage. The images were imported to a public domain imaging software, and cancellous and cortical bone coverage was computed for each image, with each implant design in various rotational positions. One single implant type could not be identified that provided the best cortical and cancellous coverage of the tibia, irrespective of using the med-1/3-axis or the ML-axis for rotational alignment. However, it could be confirmed that the best bone coverage was dependent on the selected rotational landmark. Furthermore, improved bone coverage was observed when tibial implant positions were optimized between the two rotational axes. Tibial coverage is similar for symmetric and asymmetric designs, but depends on the rotational landmark for which the implant is designed. The surgeon has the option to improve tibial coverage by optimizing placement between the two anatomic rotational alignment landmarks, the medial 1/3 and the ML-axis. Surgeons should be careful assessing intraoperative rotational tibial placement using the described anatomic rotational landmarks to optimize tibial bony coverage without compromising patella tracking. III.

  4. Bypass grafting to the anterior tibial artery.

    PubMed

    Armour, R H

    1976-01-01

    Four patients with severe ischaemia of a leg due to atherosclerotic occlusion of the tibial and peroneal arteries had reversed long saphenous vein grafts to the patent lower part of the anterior tibial artery. Two of these grafts continue to function 19 and 24 months after operation respectively. One graft failed on the fifth postoperative day and another occluded 4 months after operation. The literature on femorotibial grafting has been reviewed. The early failure rate of distal grafting is higher than in the case of femoropopliteal bypass, but a number of otherwise doomed limbs can be salvaged. Contrary to widely held views, grafting to the anterior tibial artery appears to give results comparable to those obtained when the lower anastomosis is made to the posterior tibial artery.

  5. Physeal growth arrest after tibial lengthening in achondroplasia

    PubMed Central

    2012-01-01

    Background and purpose Bilateral tibial lengthening has become one of the standard treatments for upper segment-lower segment disproportion and to improve quality of life in achondroplasia. We determined the effect of tibial lengthening on the tibial physis and compared tibial growth that occurred at the physis with that in non-operated patients with acondroplasia. Methods We performed a retrospective analysis of serial radiographs until skeletal maturity in 23 achondroplasia patients who underwent bilateral tibial lengthening before skeletal maturity (lengthening group L) and 12 achondroplasia patients of similar height and age who did not undergo tibial lengthening (control group C). The mean amount of lengthening of tibia in group L was 9.2 cm (lengthening percentage: 60%) and the mean age at the time of lengthening was 8.2 years. The mean duration of follow-up was 9.8 years. Results Skeletal maturity (fusion of physis) occurred at 15.2 years in group L and at 16.0 years in group C. The actual length of tibia (without distraction) at skeletal maturity was 238 mm in group L and 277 mm in group C (p = 0.03). The mean growth rates showed a decrease in group L relative to group C from about 2 years after surgery. Physeal closure was most pronounced on the anterolateral proximal tibial physis, with relative preservation of the distal physis. Interpretation Our findings indicate that physeal growth rate can be disturbed after tibial lengthening in achondroplasia, and a close watch should be kept for such an occurrence—especially when lengthening of more than 50% is attempted. PMID:22489887

  6. Wear mechanisms and improvements of wear resistance in cobalt-chromium alloy femoral components in artificial total knee joints

    NASA Astrophysics Data System (ADS)

    Que, Like

    Wear is one of the major causes of artificial total knee arthroplasty (TKA) failure. Wear debris can cause adverse reactions to the surrounding tissue which can ultimately lead to loosening of the prosthesis. The wear behavior of UHMWPE tibial components have been studied extensively, but relatively little attention has been paid to the CoCrMo femoral component. The goal of the present study was to investigate the wear mechanisms of CoCrMo femoral components, to study the effect of CoCrMo alloy surface roughness on the wear of UHMWPE, and to determine the effect of heat treatments on the wear resistance of the CoCrMo implant alloys. The surface roughness of twenty-seven retrieved CoCrMo femoral components was analyzed. A multiple station wear testing machine and a wear fixture attached to an MTS 858 bionix system were built and used for in vitro wear studies of the CoCrMo/UHMWPE bearing couple. Solution and aging treatments were applied to the CoCrMo alloys. A white light interference surface profilometer (WLISP) and a scanning electron microscope (SEM) were used to measure the surface roughness and to study wear mechanisms of CoCrMo alloy. An optical microscope was used for alloy microstructure study. X-ray diffraction tests were performed to identify alloy phase transformation after aging. The micro-structure, hardness, and wear resistance of the alloys were studied. Surface roughness was used to quantify alloy wear, and the minimum number of surface roughness measurements required to obtain a reliable and repeatable characterization of surface roughness for a worn alloy surface was determined. The surfaces of the retrieved CoCrMo femoral components appeared to be damaged by metal particles embedded in the UHMWPE tibial component and metal-on-metal wear due to UHMWPE tibial component through-wear. Surface roughness of the femoral components was not correlated with patient age, weight, sex, or length of implantation. In vitro wear tests showed that when the Co

  7. Measurement of the end-to-end distances between the femoral and tibial insertion sites of the anterior cruciate ligament during knee flexion and with rotational torque.

    PubMed

    Wang, Joon Ho; Kato, Yuki; Ingham, Sheila J M; Maeyama, Akira; Linde-Rosen, Monica; Smolinski, Patrick; Fu, Freddie H

    2012-10-01

    The aim of this study was to determine the end-to-end distance changes in anterior cruciate ligament (ACL) fibers during flexion/extension and internal/external rotation of the knee. The positional relation between the femur and tibia of 10 knees was digitized on a robotic system during flexion/extension and with an internal/external rotational torque (5 Nm). The ACL insertion site data, acquired by 3-dimensional scanning, were superimposed on the positional data. The end-to-end distances of 5 representative points on the femoral and tibial insertion sites of the ACL were calculated. The end-to-end distances of all representative points except the most anterior points were longest at full extension and shortest at 90°. The distances of the anteromedial (AM) and posterolateral (PL) bundles were 37.2 ± 2.1 mm and 27.5 ± 2.8 mm, respectively, at full extension and 34.7 ± 2.4 mm and 20.7 ± 2.3 mm, respectively, at 90°. Only 4 knees had an isometric point, which was 1 of the 3 anterior points. Under an internal torque, both bundles became longer with statistical meaning at all flexion angles (P = .005). The end-to-end distances of all points became longest with internal torque at full extension and shortest with an external torque at 90°. Only 4 of 10 specimens had an isometric point at a variable anterior point. The end-to-end distances of the AM and PL bundles were longer in extension and shorter in flexion. The nonisometric tendency of the ACL and the end-to-end distance change during knee flexion/extension and internal/external rotation should be considered during ACL reconstruction to avoid overconstraint of the graft. Copyright © 2012 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  8. Instrumented socket inserts for sensing interaction at the limb-socket interface.

    PubMed

    Swanson, Eric C; McLean, Jake B; Allyn, Katheryn J; Redd, Christian B; Sanders, Joan E

    2018-01-01

    The objective of this research was to investigate a strategy for designing and fabricating computer-manufactured socket inserts that were embedded with sensors for field monitoring of limb-socket interactions of prosthetic users. An instrumented insert was fabricated for a single trans-tibial prosthesis user that contained three sensor types (proximity sensor, force sensing resistor, and inductive sensor), and the system was evaluated through a sequence of laboratory clinical tests and two days of field use. During in-lab tests 3 proximity sensors accurately distinguish between don and doff states; 3 of 4 force sensing resistors measured gradual pressure increases as weight-bearing increased; and the inductive sensor indicated that as prosthetic socks were added the limb moved farther out of the socket and pistoning amplitude decreased. Multiple sensor types were necessary in analysis of field collected data to interpret how sock changes affected limb-socket interactions. Instrumented socket inserts, with sensors selected to match clinical questions of interest, have the potential to provide important insights to improve patient care. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

  9. Tension band plating of a nonunion anterior tibial stress fracture in an athlete.

    PubMed

    Merriman, Jarrad A; Villacis, Diego; Kephart, Curtis J; Rick Hatch, George F

    2013-07-01

    The authors present a rare technique of tension band plating of the anterior tibia in the setting of a nonunion stress fracture. Surgical management with an intramedullary nail is a viable and proven option for treating such injuries. However, in treating elite athletes, legitimate concerns exist regarding the surgical disruption of the extensor mechanism and the risk of anterior knee pain associated with intramedullary nail use. The described surgical technique demonstrates the use of tension band plating as an effective treatment of delayed union and nonunion anterior tibial stress fractures in athletes without the potential risks of intramedullary nail insertion. Copyright 2013, SLACK Incorporated.

  10. Gait Parameters and Functional Outcomes After Total Knee Arthroplasty Using Persona Knee System With Cruciate Retaining and Ultracongruent Knee Inserts.

    PubMed

    Rajgopal, Ashok; Aggarwal, Kalpana; Khurana, Anshika; Rao, Arun; Vasdev, Attique; Pandit, Hemant

    2017-01-01

    Total knee arthroplasty is a well-established treatment for managing end-stage symptomatic knee osteoarthritis. Currently, different designs of prostheses are available with majority ensuring similar clinical outcomes. Altered surface geometry is introduced to strive toward gaining superior outcomes. We aimed to investigate any differences in functional outcomes between 2 different polyethylene designs namely the Persona CR (cruciate retaining) and Persona UC (ultracongruent) tibial inserts (Zimmer-Biomet, Warsaw, IN). This prospective single blind, single-surgeon randomized controlled trial reports on 105 patients, (66 female and 39 male), who underwent simultaneous bilateral total knee arthroplasty using the Persona knee system (Zimmer-Biomet) UC inserts in one side and CR inserts in the contralateral side. By a blind assessor, at regular time intervals patients were assessed in terms of function and gait. The functional knee scoring scales used were the Western Ontario and McMaster Universities Osteoarthritis Index and Modified Knee Society Score. The gait parameters evaluated were foot pressure and step length. During the study period, no patient was lost to follow-up or underwent revision surgery for any cause. Western Ontario and McMaster Universities Osteoarthritis Index scores, Modified Knee Society Score, and knee range of motion of all 105 patients assessed preoperatively and postoperatively at 6 months, 1 year, and 2 years showed statistically better results (P < .05) for UC inserts. Gait analysis measuring foot pressures and step length, however, did not show any statistically significant differences at 2-year follow-up. Ultracongruent tibial inserts show significantly better functional outcomes as compared to CR inserts during a 2-year follow-up period. However, in this study these findings were not shown to be attributed to differences in gait parameters. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Polyaxial Screws in Locked Plating of Tibial Pilon Fractures.

    PubMed

    Yenna, Zachary C; Bhadra, Arup K; Ojike, Nwakile I; Burden, Robert L; Voor, Michael J; Roberts, Craig S

    2015-08-01

    This study examined the axial and torsional stiffness of polyaxial locked plating techniques compared with fixed-angle locked plating techniques in a distal tibia pilon fracture model. The effect of using a polyaxial screw to cross the fracture site was examined to determine its ability to control relative fracture site motion. A laboratory experiment was performed to investigate the biomechanical stiffness of distal tibia fracture models repaired with 3.5-mm anterior polyaxial distal tibial plates and locking screws. Sawbones Fourth Generation Composite Tibia models (Pacific Research Laboratories, Inc, Vashon, Washington) were used to model an Orthopaedic Trauma Association 43-A1.3 distal tibia pilon fracture. The polyaxial plates were inserted with 2 central locking screws at a position perpendicular to the cortical surface of the tibia and tested for load as a function of axial displacement and torque as a function of angular displacement. The 2 screws were withdrawn and inserted at an angle 15° from perpendicular, allowing them to span the fracture and insert into the opposing fracture surface. Each tibia was tested again for axial and torsional stiffness. In medial and posterior loading, no statistically significant difference was found between tibiae plated with the polyaxial plate and the central screws placed in the neutral position compared with the central screws placed at a 15° position. In torsional loading, a statistically significant difference was noted, showing greater stiffness in tibiae plated with the polyaxial plate and the central screws placed at a 15° position compared with tibiae plated with the central screws placed at a 0° (or perpendicular) position. This study showed that variable angle constructs show similar stiffness properties between perpendicular and 15° angle insertions in axial loading. The 15° angle construct shows greater stiffness in torsional loading. Copyright 2015, SLACK Incorporated.

  12. Bilateral double level tibial lengthening in dwarfism.

    PubMed

    Burghardt, Rolf D; Yoshino, Koichi; Kashiwagi, Naoya; Yoshino, Shigeo; Bhave, Anil; Paley, Dror; Herzenberg, John E

    2015-12-01

    Outcome assessment after double level tibial lengthening in patients with dwarfism. Fourteen patients with dwarfism were analyzed after bilateral simultaneous double level tibial lengthening. Average age was 15.1 years. Average lengthening was 13.5 cm. The two levels were lengthened by an average of 7.5 cm proximally and 6.0 cm distally. Concomitant deformities were also addressed during lengthening. External fixation treatment time averaged 8.8 months. Healing index averaged 0.7 months/cm. Bilateral tibial lengthening for dwarfism is difficult, but the results are usually quite gratifying.

  13. Minimizing Alteration of Posterior Tibial Slope During Opening Wedge High Tibial Osteotomy: a Protocol with Experimental Validation in Paired Cadaveric Knees

    PubMed Central

    Westermann, Robert W; DeBerardino, Thomas; Amendola, Annunziato

    2014-01-01

    Introduction The High Tibial Osteotomy (HTO) is a reliable procedure in addressing uni- compartmental arthritis with associated coronal deformities. With osteotomy of the proximal tibia, there is a risk of altering the tibial slope in the sagittal plane. Surgical techniques continue to evolve with trends towards procedure reproducibility and simplification. We evaluated a modification of the Arthrex iBalance technique in 18 paired cadaveric knees with the goals of maintaining sagittal slope, increasing procedure efficiency, and decreasing use of intraoperative fluoroscopy. Methods Nine paired cadaveric knees (18 legs) underwent iBalance medial opening wedge high tibial osteotomies. In each pair, the right knee underwent an HTO using the modified technique, while all left knees underwent the traditional technique. Independent observers evaluated postoperative factors including tibial slope, placement of hinge pin, and implant placement. Specimens were then dissected to evaluate for any gross muscle, nerve or vessel injury. Results Changes to posterior tibial slope were similar using each technique. The change in slope in traditional iBalance technique was -0.3° ±2.3° and change in tibial slope using the modified iBalance technique was -0.4° ±2.3° (p=0.29). Furthermore, we detected no differences in posterior tibial slope between preoperative and postoperative specimens (p=0.74 traditional, p=0.75 modified). No differences in implant placement were detected between traditional and modified techniques. (p=0.85). No intraoperative iatrogenic complications (i.e. lateral cortex fracture, blood vessel or nerve injury) were observed in either group after gross dissection. Discussion & Conclusions Alterations in posterior tibial slope are associated with HTOs. Both traditional and modified iBalance techniques appear reliable in coronal plane corrections without changing posterior tibial slope. The present modification of the Arthrex iBalance technique may increase the

  14. Proximal tibial osteotomy. A survivorship analysis.

    PubMed

    Ritter, M A; Fechtman, R A

    1988-01-01

    Proximal tibial osteotomy is generally accepted as a treatment for the patient with unicompartmental arthritis. However, a few reports of the long-term results of this procedure are available in the literature, and none have used the technique known as survivorship analysis. This technique has an advantage over conventional analysis because it does not exclude patients for inadequate follow-up, loss to follow-up, or patient death. In this study, survivorship analysis was applied to 78 proximal tibial osteotomies, performed exclusively by the senior author for the correction of a preoperative varus deformity, and a survival curve was constructed. It was concluded that the reliable longevity of the proximal tibial osteotomy is approximately 6 years.

  15. Compartment syndrome after tibial plateau fracture☆

    PubMed Central

    Pitta, Guilherme Benjamin Brandão; dos Santos, Thays Fernanda Avelino; dos Santos, Fernanda Thaysa Avelino; da Costa Filho, Edelson Moreira

    2014-01-01

    Fractures of the tibial plateau are relatively rare, representing around 1.2% of all fractures. The tibia, due to its subcutaneous location and poor muscle coverage, is exposed and suffers large numbers of traumas, not only fractures, but also crush injuries and severe bruising, among others, which at any given moment, could lead compartment syndrome in the patient. The case is reported of a 58-year-old patient who, following a tibial plateau fracture, presented compartment syndrome of the leg and was submitted to decompressive fasciotomy of the four right compartments. After osteosynthesis with internal fixation of the tibial plateau using an L-plate, the patient again developed compartment syndrome. PMID:26229779

  16. [Damping inserts have no load reducing effect in the fatigued state].

    PubMed

    Melnyk, M; Gollhofer, A

    2008-09-01

    Overload injuries to the lower limbs may be attributed to repetitive, non-physiological load stimuli. However, these impact loads acting on the musculoskeletal can be reduced by wearing damping inserts. To date, however, there is only little evidence as to whether this positive effect can be assigned to the damping insert and, furthermore, whether this effect is detectable in states of muscle fatigue. Therefore, the influence of muscle fatigue in combination with the wearing of damping inserts was investigated in 13 subjects. The parameters examined in this study were ground reaction forces during walking and the muscular activation profile of the lower limb in the phase of initial ground contact. The results showed that neither in comparisons with and without damping inserts nor in states of muscular fatigue could significant differences were found in the ground reaction forces. Wereas, no significant differences could be detected in the investigated muscles, with and without damping inserts, preactivation in the peroneal and biceps femoris muscles were significantly earlier, in states of muscular fatigue with damping inserts, while no changes could be found in the anterior tibial, soleus, vastus lateralis and gastrocnemius muscles. The present results demonstrate that wearing damping inserts does not lead to a positive effect with regard to a reduction of the ground reaction forces. The earlier preactivation in the case of muscle fatigue with a damping insert is indicative of an increased energy expenditure which may be possibly associated with increased knee and ankle joint control. The high satisfaction concerning the comfort of wearing such inserts revealed by a questionnaire did not correlate with a reduction in loading condition. On the basis of the present results we cannot recommend the wearing of damping soft sole inserts in the context of a reduction in load condition.

  17. Tibial lengthening over intramedullary nails

    PubMed Central

    Burghardt, R. D.; Manzotti, A.; Bhave, A.; Paley, D.

    2016-01-01

    Objectives The purpose of this study was to compare the results and complications of tibial lengthening over an intramedullary nail with treatment using the traditional Ilizarov method. Methods In this matched case study, 16 adult patients underwent 19 tibial lengthening over nails (LON) procedures. For the matched case group, 17 patients who underwent 19 Ilizarov tibial lengthenings were retrospectively matched to the LON group. Results The mean external fixation time for the LON group was 2.6 months and for the matched case group was 7.6 months. The mean lengthening amounts for the LON and the matched case groups were 5.2 cm and 4.9 cm, respectively. The radiographic consolidation time in the LON group was 6.6 months and in the matched case group 7.6 months. Using a clinical and radiographic outcome score that was designed for this study, the outcome was determined to be excellent in 17 and good in two patients for the LON group. The outcome was excellent in 14 and good in five patients in the matched case group. The LON group had increased blood loss and increased cost. The LON group had four deep infections; the matched case group did not have any deep infections. Conclusions The outcomes in the LON group were comparable with the outcomes in the matched case group. The LON group had a shorter external fixation time but experienced increased blood loss, increased cost, and four cases of deep infection. The advantage of reducing external fixation treatment time may outweigh these disadvantages in patients who have a healthy soft-tissue envelope. Cite this article: J. E. Herzenberg. Tibial lengthening over intramedullary nails: A matched case comparison with Ilizarov tibial lengthening. Bone Joint Res 2016;5:1–10. doi: 10.1302/2046-3758.51.2000577 PMID:26764351

  18. Inflammatory response against different carbon fiber-reinforced PEEK wear particles compared with UHMWPE in vivo.

    PubMed

    Utzschneider, Sandra; Becker, Fabian; Grupp, Thomas M; Sievers, Birte; Paulus, Alexander; Gottschalk, Oliver; Jansson, Volkmar

    2010-11-01

    Poly(ether ether ketone) (PEEK) and its composites are recognized as alternative bearing materials for use in arthroplasty because of their mechanical properties. The objective of this project was to evaluate the biological response of two different kinds of carbon fiber-reinforced (CFR) PEEK compared with ultra-high molecular weight polyethylene (UHMWPE) in vivo as a standard bearing material. Wear particles of the particulate biomaterials were injected into the left knee joint of female BALB/c mice. Assessment of the synovial microcirculation using intravital fluorescence microscopy as well as histological evaluation of the synovial layer were performed 7 days after particle injection. Enhanced leukocyte-endothelial cell interactions and an increase in functional capillary density as well as histological investigations revealed that all tested biomaterials caused significantly (P < 0.05) increased inflammatory reactions compared with control animals (injected with sterile phosphate-buffered saline), without any difference between the tested biomaterials (P > 0.05). These data suggest that wear debris of CFR-PEEK is comparable with UHMWPE in its biological activity. Therefore, CFR-PEEK represents an alternative bearing material because of its superior mechanical and chemical behavior without any increased biological activity of the wear particles, compared with a standard bearing material. Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  19. High tibial osteotomy in knee laxities: Concepts review and results

    PubMed Central

    Robin, Jonathan G.; Neyret, Philippe

    2016-01-01

    Patients with unstable, malaligned knees often present a challenging management scenario, and careful attention must be paid to the clinical history and examination to determine the priorities of treatment. Isolated knee instability treated with ligament reconstruction and isolated knee malalignment treated with periarticular osteotomy have both been well studied in the past. More recently, the effects of high tibial osteotomy on knee instability have been studied. Lateral closing-wedge high tibial osteotomy tends to reduce the posterior tibial slope, which has a stabilising effect on anterior tibial instability that occurs with ACL deficiency. Medial opening-wedge high tibial osteotomy tends to increase the posterior tibia slope, which has a stabilising effect in posterior tibial instability that occurs with PCL deficiency. Overall results from recent studies indicate that there is a role for combined ligament reconstruction and periarticular knee osteotomy. The use of high tibial osteotomy has been able to extend the indication for ligament reconstruction which, when combined, may ultimately halt the evolution of arthritis and preserve their natural knee joint for a longer period of time. Cite this article: Robin JG, Neyret P. High tibial osteotomy in knee laxities: Concepts review and results. EFORT Open Rev 2016;1:3-11. doi: 10.1302/2058-5241.1.000001. PMID:28461908

  20. MRI analysis of tibial PCL attachment in a large population of adult patients: reference data for anatomic PCL reconstruction.

    PubMed

    Teng, Yuanjun; Guo, Laiwei; Wu, Meng; Xu, Tianen; Zhao, Lianggong; Jiang, Jin; Sheng, Xiaoyun; Xu, Lihu; Zhang, Bo; Ding, Ning; Xia, Yayi

    2016-09-05

    data of the tibial PCL attachment based on MRI in the sagittal orientation. In analysis of retrospective data from a large population of adult patients, the quantitative values can be used as references to define the inserted angle and depth of the drill guide, and the exact position and size of the tibial PCL tunnel for performing arthroscopic anatomic PCL reconstruction.

  1. Predictive formula for the length of tibial tunnel in anterior crucitate ligament reconstruction.

    PubMed

    Chernchujit, Bancha; Barthel, Thomas

    2009-12-01

    The anterior cruciate ligament (ACL) reconstruction using bone-patellar tendon bone graft is a common procedure in orthopedics. One challenging problem found is a graft-tunnel mismatch. Previous studies have reported the mathematic formula to predict the tibial angle length and angle to avoid graft-tunnel mismatch but these formulas have shown limited predictability. To propose a predictive formula for the length of tibial tunnel and to examine its predictability. Thirty six patients (26 males, 14 females) with ACL injury were included in this study. The preoperativemedial proximal tibial angle was measured. Intraoperatively, the tibial tunnel length and tibial entry point were measured. The postoperative coronal and saggital angle of tibial tunnel were measured from knee radiograph. The data were analysed by using trigonometry correlation and formulate the predictive formula of tibial tunnel length. We found that tibial tunnel length (T) has trigonometric correlation between the location of tibial tunnel entry point (w), coronal angle of tibial tunnel (b), saggital angle of tibial tunnel (a) and the medial proximal tibial slope (c) by using this formula T = Wcos(c)tan(b)/sin(a) This proposed predictive formula can well predict the length of the tibial tunnel at preoperative period to avoid graft-tunnel mismatch.

  2. Cross-linked polyethylene does not reduce wear in total knee arthroplasty.

    PubMed

    Lasurt-Bachs, S; Torner, P; Maculé, F; Prats, E; Menéndez-García, F; Ríos-Guillermo, J; Torrents, A

    To compare two different types of inserts: Ultra-high molecular weight polyethylene (UHMWPE) and cross-linked polyethylene with a quantitative and qualitative study of polyethylene wear particles in synovial fluid 3 years after total knee arthroplasty. A prospective, randomized, controlled cohort study with blinded evaluation was carried out on 25 patients undergoing staged bilateral total knee replacement, 6 months apart. Knee arthrocentesis was performed on 12 patients 3 years after surgery, and the polyethylene particles were analyzed. No significant differences were found in the number of particles generated by the two different types of inserts at 3 years from total knee arthroplasty (3,000×: x¯ cross-linked=849.7; x¯ UHMWPE=796.9; P=.63; 20,000×: x¯ cross-linked=66.3; x¯ UHMWPE=73.1; P=.76). Likewise, no differences in the probability of finding elongated (χ 2 =0.19; P=.66) or rounded (χ 2 =1.44; P=.23) particles in both types of inserts were observed. However, the probability of finding fibrillar particles is 3.08 times greater in UHMWPE. Cross-linked polyethylene does not significantly reduce the generation of polyethylene particles in patients with total knee arthroplasty, 3 years after the surgical procedure. Copyright © 2018 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

  3. Models of tibial fracture healing in normal and Nf1-deficient mice.

    PubMed

    Schindeler, Aaron; Morse, Alyson; Harry, Lorraine; Godfrey, Craig; Mikulec, Kathy; McDonald, Michelle; Gasser, Jürg A; Little, David G

    2008-08-01

    Delayed union and nonunion are common complications associated with tibial fractures, particularly in the distal tibia. Existing mouse tibial fracture models are typically closed and middiaphyseal, and thus poorly recapitulate the prevailing conditions following surgery on a human open distal tibial fracture. This report describes our development of two open tibial fracture models in the mouse, where the bone is broken either in the tibial midshaft (mid-diaphysis) or in the distal tibia. Fractures in the distal tibial model showed delayed repair compared to fractures in the tibial midshaft. These tibial fracture models were applied to both wild-type and Nf1-deficient (Nf1+/-) mice. Bone repair has been reported to be exceptionally problematic in human NF1 patients, and these patients can also spontaneously develop tibial nonunions (known as congenital pseudarthrosis of the tibia), which are recalcitrant to even vigorous intervention. pQCT analysis confirmed no fundamental differences in cortical or cancellous bone in Nf1-deficient mouse tibiae compared to wild-type mice. Although no difference in bone healing was seen in the tibial midshaft fracture model, the healing of distal tibial fractures was found to be impaired in Nf1+/- mice. The histological features associated with nonunited Nf1+/- fractures were variable, but included delayed cartilage removal, disproportionate fibrous invasion, insufficient new bone anabolism, and excessive catabolism. These findings imply that the pathology of tibial pseudarthrosis in human NF1 is complex and likely to be multifactorial.

  4. Proximal tibial fracture following anterior cruciate ligament reconstruction surgery: a biomechanical analysis of the tibial tunnel as a stress riser.

    PubMed

    Aldebeyan, Wassim; Liddell, Antony; Steffen, Thomas; Beckman, Lorne; Martineau, Paul A

    2017-08-01

    This is the first biomechanical study to examine the potential stress riser effect of the tibial tunnel or tunnels after ACL reconstruction surgery. In keeping with literature, the primary hypothesis tested in this study was that the tibial tunnel acts as a stress riser for fracture propagation. Secondary hypotheses were that the stress riser effect increases with the size of the tunnel (8 vs. 10 mm), the orientation of the tunnel [standard (STT) vs. modified transtibial (MTT)], and with the number of tunnels (1 vs. 2). Tibial tunnels simulating both single bundle hamstring graft (8 mm) and bone-patellar tendon-bone graft (10 mm) either STT or MTT position, as well as tunnels simulating double bundle (DB) ACL reconstruction (7, 6 mm), were drilled in fourth-generation saw bones. These five experimental groups and a control group consisting of native saw bones without tunnels were loaded to failure on a Materials Testing System to simulate tibial plateau fracture. There were no statistically significant differences in peak load to failure between any of the groups, including the control group. The fracture occurred through the tibial tunnel in 100 % of the MTT tunnels (8 and 10 mm) and 80 % of the DB tunnels specimens; however, the fractures never (0 %) occurred through the tibial tunnel of the standard tunnels (8 or 10 mm) (P = 0.032). In the biomechanical model, the tibial tunnel does not appear to be a stress riser for fracture propagation, despite suggestions to the contrary in the literature. Use of a standard, more vertical tunnel decreases the risk of ACL graft compromise in the event of a fracture. This may help to inform surgical decision making on ACL reconstruction technique.

  5. Measurement of Posterior Tibial Slope Using Magnetic Resonance Imaging.

    PubMed

    Karimi, Elham; Norouzian, Mohsen; Birjandinejad, Ali; Zandi, Reza; Makhmalbaf, Hadi

    2017-11-01

    Posterior tibial slope (PTS) is an important factor in the knee joint biomechanics and one of the bone features, which affects knee joint stability. Posterior tibial slope has impact on flexion gap, knee joint stability and posterior femoral rollback that are related to wide range of knee motion. During high tibial osteotomy and total knee arthroplasty (TKA) surgery, proper retaining the mechanical and anatomical axis is important. The aim of this study was to evaluate the value of posterior tibial slope in medial and lateral compartments of tibial plateau and to assess the relationship among the slope with age, gender and other variables of tibial plateau surface. This descriptive study was conducted on 132 healthy knees (80 males and 52 females) with a mean age of 38.26±11.45 (20-60 years) at Imam Reza hospital in Mashhad, Iran. All patients, selected and enrolled for MRI in this study, were admitted for knee pain with uncertain clinical history. According to initial physical knee examinations the study subjects were reported healthy. The mean posterior tibial slope was 7.78± 2.48 degrees in the medial compartment and 6.85± 2.24 degrees in lateral compartment. No significant correlation was found between age and gender with posterior tibial slope ( P ≥0.05), but there was significant relationship among PTS with mediolateral width, plateau area and medial plateau. Comparison of different studies revealed that the PTS value in our study is different from other communities, which can be associated with genetic and racial factors. The results of our study are useful to PTS reconstruction in surgeries.

  6. Tibial Stress Injuries: Decisive Diagnosis and Treatment of "Shin Splints."

    ERIC Educational Resources Information Center

    Couture, Christopher J.; Karlson, Kristine A.

    2002-01-01

    Tibial stress injuries, commonly called shin splints, often result when bone remodeling processes adopt inadequately to repetitive stress. Physicians who are caring for athletic patients must have a thorough understanding of this continuum of injuries, including medial tibial stress syndrome and tibial stress fractures, because there are…

  7. Tibial Eminence Involvement With Tibial Plateau Fracture Predicts Slower Recovery and Worse Postoperative Range of Knee Motion.

    PubMed

    Konda, Sanjit R; Driesman, Adam; Manoli, Arthur; Davidovitch, Roy I; Egol, Kenneth A

    2017-07-01

    To examine 1-year functional and clinical outcomes in patients with tibial plateau fractures with tibial eminence involvement. Retrospective analysis of prospectively collected data. Academic Medical Center. All patients who presented with a tibial plateau fracture (Orthopaedic Trauma Association (OTA) 41-B and 41-C). Patients were divided into fractures with a tibial eminence component (+TE) and those without (-TE) cohorts. All patients underwent similar surgical approaches and fixation techniques for fractures. No tibial eminence fractures received fixation specifically. Short musculoskeletal functional assessment (SMFA), pain (Visual Analogue Scale), and knee range-of-motion (ROM) were evaluated at 3, 6, and 12 months postoperatively and compared between cohorts. Two hundred ninety-three patients were included for review. Patients with OTA 41-C fractures were more likely to have an associated TE compared with 41-B fractures (63% vs. 28%, P < 0.01). At 3 months postoperatively, the +TE cohort was noted to have worse knee ROM (75.16 ± 51 vs. 86.82 ± 53 degree, P = 0.06). At 6 months, total SMFA and knee ROM was significantly worse in the +TE cohort (29 ± 17 vs. 21 ± 18, P ≤ 0.01; 115.6 ± 20 vs. 124.1 ± 15, P = 0.01). By 12 months postoperatively, only knee ROM remained significantly worse in the +TE cohort (118.7 ± 15 vs. 126.9 ± 13, P < 0.01). Multivariate analysis revealed that tibial eminence involvement was a significant predictor of ROM at 6 and 12 months and SFMA at 6 months. Body mass index was found to be a significant predictor of ROM and age was a significant predictor of total SMFA at all time points. Knee ROM remains worse throughout the postoperative period in the +TE cohort. Functional outcome improves less rapidly in the +TE cohort but achieves similar results by 1 year. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

  8. Medial tibial plateau morphology and stress fracture location: A magnetic resonance imaging study.

    PubMed

    Yukata, Kiminori; Yamanaka, Issei; Ueda, Yuzuru; Nakai, Sho; Ogasa, Hiroyoshi; Oishi, Yosuke; Hamawaki, Jun-Ichi

    2017-06-18

    To determine the location of medial tibial plateau stress fractures and its relationship with tibial plateau morphology using magnetic resonance imaging (MRI). A retrospective review of patients with a diagnosis of stress fracture of the medial tibial plateau was performed for a 5-year period. Fourteen patients [three female and 11 male, with an average age of 36.4 years (range, 15-50 years)], who underwent knee MRI, were included. The appearance of the tibial plateau stress fracture and the geometry of the tibial plateau were reviewed and measured on MRI. Thirteen of 14 stress fractures were linear, and one of them stellated on MRI images. The location of fractures was classified into three types. Three fractures were located anteromedially (AM type), six posteromedially (PM type), and five posteriorly (P type) at the medial tibial plateau. In addition, tibial posterior slope at the medial tibial plateau tended to be larger when the fracture was located more posteriorly on MRI. We found that MRI showed three different localizations of medial tibial plateau stress fractures, which were associated with tibial posterior slope at the medial tibial plateau.

  9. Medial tibial plateau morphology and stress fracture location: A magnetic resonance imaging study

    PubMed Central

    Yukata, Kiminori; Yamanaka, Issei; Ueda, Yuzuru; Nakai, Sho; Ogasa, Hiroyoshi; Oishi, Yosuke; Hamawaki, Jun-ichi

    2017-01-01

    AIM To determine the location of medial tibial plateau stress fractures and its relationship with tibial plateau morphology using magnetic resonance imaging (MRI). METHODS A retrospective review of patients with a diagnosis of stress fracture of the medial tibial plateau was performed for a 5-year period. Fourteen patients [three female and 11 male, with an average age of 36.4 years (range, 15-50 years)], who underwent knee MRI, were included. The appearance of the tibial plateau stress fracture and the geometry of the tibial plateau were reviewed and measured on MRI. RESULTS Thirteen of 14 stress fractures were linear, and one of them stellated on MRI images. The location of fractures was classified into three types. Three fractures were located anteromedially (AM type), six posteromedially (PM type), and five posteriorly (P type) at the medial tibial plateau. In addition, tibial posterior slope at the medial tibial plateau tended to be larger when the fracture was located more posteriorly on MRI. CONCLUSION We found that MRI showed three different localizations of medial tibial plateau stress fractures, which were associated with tibial posterior slope at the medial tibial plateau. PMID:28660141

  10. [Surgical approaches to tibial plateau fractures].

    PubMed

    Krause, Matthias; Müller, Gunnar; Frosch, Karl-Heinz

    2018-06-06

    Intra-articular tibial plateau fractures can present a surgical challenge due to complex injury patterns and compromised soft tissue. The treatment goal is to spare the soft tissue and an anatomical reconstruction of the tibial articular surface. Depending on the course of the fracture, a fracture-specific access strategy is recommended to provide correct positioning of the plate osteosynthesis. While the anterolateral approach is used in the majority of lateral tibial plateau fractures, only one third of the joint surface is visible; however, posterolateral fragments require an individual approach, e. g. posterolateral or posteromedial. If necessary, osteotomy of the femoral epicondyles can improve joint access for reduction control. Injuries to the posterior columns should be anatomically reconstructed and biomechanically correctly addressed via posterior approaches. Bony posterior cruciate ligament tears can be refixed via a minimally invasive posteromedial approach.

  11. Tibial stress injuries: decisive diagnosis and treatment of 'shin splints'.

    PubMed

    Couture, Christopher J; Karlson, Kristine A

    2002-06-01

    Tibial stress injuries, commonly called 'shin splints,' often result when bone remodeling processes adapt inadequately to repetitive stress. Physicians who care for athletic patients need a thorough understanding of this continuum of injuries, including medial tibial stress syndrome and tibial stress fractures, because there are implications for appropriate diagnosis, management, and prevention.

  12. Understanding the etiology of the posteromedial tibial stress fracture.

    PubMed

    Milgrom, Charles; Burr, David B; Finestone, Aharon S; Voloshin, Arkady

    2015-09-01

    Previous human in vivo tibial strain measurements from surface strain gauges during vigorous activities were found to be below the threshold value of repetitive cyclical loading at 2500 microstrain in tension necessary to reduce the fatigue life of bone, based on ex vivo studies. Therefore it has been hypothesized that an intermediate bone remodeling response might play a role in the development of tibial stress fractures. In young adults tibial stress fractures are usually oblique, suggesting that they are the result of failure under shear strain. Strains were measured using surface mounted unstacked 45° rosette strain gauges on the posterior aspect of the flat medial cortex just below the tibial midshaft, in a 48year old male subject while performing vertical jumps, staircase jumps and running up and down stadium stairs. Shear strains approaching 5000 microstrain were recorded during stair jumping and vertical standing jumps. Shear strains above 1250 microstrain were recorded during runs up and down stadium steps. Based on predictions from ex vivo studies, stair and vertical jumping tibial shear strain in the test subject was high enough to potentially produce tibial stress fracture subsequent to repetitive cyclic loading without necessarily requiring an intermediate remodeling response to microdamage. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Temporary Fixation Using a Long Femoral-tibial Nail to Treat a Displaced Medial Tibial Plateau Fracture in a 90-year-old Patient: A Case Report.

    PubMed

    Batta, V; Sinha, S; Trompeter, A

    2017-01-01

    Tibial plateau fractures are complex injuries in the elderly population. When traditional methods of fixation are not suitable, an alternative method needs to be chosen for a favorable outcome. We demonstrate a previously undescribed treatment for displaced tibial plateau fractures in the very elderly with poor soft-tissue integrity. A 90-year-old woman suffered an open, Gustilo Grade IIIA, displaced fracture of the tibial plateau. An intramedullary knee arthrodesis, the femoral-tibial nail was used to temporarily stabilize her fracture. She was able to weight bear immediately postfixation. A long femoral-tibial nail allows favorable fracture and soft tissue healing, ease of nursing and immediate full weight-bearing. It shows good promise and should be considered as a management option when traditional methods are not applicable in select patients.

  14. Bone stress in runners with tibial stress fracture.

    PubMed

    Meardon, Stacey A; Willson, John D; Gries, Samantha R; Kernozek, Thomas W; Derrick, Timothy R

    2015-11-01

    Combinations of smaller bone geometry and greater applied loads may contribute to tibial stress fracture. We examined tibial bone stress, accounting for geometry and applied loads, in runners with stress fracture. 23 runners with a history of tibial stress fracture & 23 matched controls ran over a force platform while 3-D kinematic and kinetic data were collected. An elliptical model of the distal 1/3 tibia cross section was used to estimate stress at 4 locations (anterior, posterior, medial and lateral). Inner and outer radii for the model were obtained from 2 planar x-ray images. Bone stress differences were assessed using two-factor ANOVA (α=0.05). Key contributors to observed stress differences between groups were examined using stepwise regression. Runners with tibial stress fracture experienced greater anterior tension and posterior compression at the distal tibia. Location, but not group, differences in shear stress were observed. Stepwise regression revealed that anterior-posterior outer diameter of the tibia and the sagittal plane bending moment explained >80% of the variance in anterior and posterior bone stress. Runners with tibial stress fracture displayed greater stress anteriorly and posteriorly at the distal tibia. Elevated tibial stress was associated with smaller bone geometry and greater bending moments about the medial-lateral axis of the tibia. Future research needs to identify key running mechanics associated with the sagittal plane bending moment at the distal tibia as well as to identify ways to improve bone geometry in runners in order to better guide preventative and rehabilitative efforts. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Tibial stress fracture after computer-navigated total knee arthroplasty.

    PubMed

    Massai, F; Conteduca, F; Vadalà, A; Iorio, R; Basiglini, L; Ferretti, A

    2010-06-01

    A correct alignment of the tibial and femoral component is one of the most important factors determining favourable long-term results of a total knee arthroplasty (TKA). The accuracy provided by the use of the computer navigation systems has been widely described in the literature so that their use has become increasingly popular in recent years; however, unpredictable complications, such as displaced or stress femoral or tibial fractures, have been reported to occur a few weeks after the operation. We present a case of a stress tibial fracture that occurred after a TKA performed with the use of a computer navigation system. The stress fracture, which eventually healed without further complications, occurred at one of the pinhole sites used for the placement of the tibial trackers.

  16. Management of tibial non-unions according to a novel treatment algorithm.

    PubMed

    Ferreira, Nando; Marais, Leonard Charles

    2015-12-01

    Tibial non-unions represent a spectrum of conditions that are challenging to treat. The optimal management remains unclear despite the frequency with which these diagnoses are encountered. The aim of this study was to determine the outcome of tibial non-unions managed according to a novel tibial non-union treatment algorithm. One hundred and eighteen consecutive patients with 122 uninfected tibial non-unions were treated according to our proposed tibial non-union treatment algorithm. All patients were followed-up clinically and radiologically for a minimum of six months after external fixator removal. Four patients were excluded because they did not complete the intended treatment process. The final study population consisted of 94 men and 24 women with a mean age of 34 years. Sixty-seven non-unions were stiff hypertrophic, 32 mobile atrophic, 16 mobile oligotrophic and one true pseudoarthrosis. Six non-unions were classified as type B1 defect non-unions. Bony union was achieved after the initial surgery in 113/122 (92.6%) tibias. Nine patients had failure of treatment. Seven persistent non-unions were successfully retreated according to the tibial non-union treatment algorithm. This resulted in final bony union in 120/122 (98.3%) tibias. The proposed tibial non-union treatment algorithm appears to produce high union rates across a diverse group of tibial non-unions. Tibial non-unions however, remain difficult to treat and should be referred to specialist units where advanced reconstructive techniques are practiced on a regular basis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Temporary Fixation Using a Long Femoral-tibial Nail to Treat a Displaced Medial Tibial Plateau Fracture in a 90-year-old Patient: A Case Report

    PubMed Central

    Batta, V; Sinha, S; Trompeter, A

    2017-01-01

    Introduction: Tibial plateau fractures are complex injuries in the elderly population. When traditional methods of fixation are not suitable, an alternative method needs to be chosen for a favorable outcome. We demonstrate a previously undescribed treatment for displaced tibial plateau fractures in the very elderly with poor soft-tissue integrity. Case Report: A 90-year-old woman suffered an open, Gustilo Grade IIIA, displaced fracture of the tibial plateau. An intramedullary knee arthrodesis, the femoral-tibial nail was used to temporarily stabilize her fracture. She was able to weight bear immediately postfixation. Conclusion: A long femoral-tibial nail allows favorable fracture and soft tissue healing, ease of nursing and immediate full weight-bearing. It shows good promise and should be considered as a management option when traditional methods are not applicable in select patients. PMID:29181350

  18. The effect of muscle fatigue on in vivo tibial strains.

    PubMed

    Milgrom, Charles; Radeva-Petrova, Denitsa R; Finestone, Aharon; Nyska, Meir; Mendelson, Stephen; Benjuya, Nisim; Simkin, Ariel; Burr, David

    2007-01-01

    Stress fracture is a common musculoskeletal problem affecting athletes and soldiers. Repetitive high bone strains and strain rates are considered to be its etiology. The strain level necessary to cause fatigue failure of bone ex vivo is higher than the strains recorded in humans during vigorous physical activity. We hypothesized that during fatiguing exercises, bone strains may increase and reach levels exceeding those measured in the non-fatigued state. To test this hypothesis, we measured in vivo tibial strains, the maximum gastrocnemius isokinetic torque and ground reaction forces in four subjects before and after two fatiguing levels of exercise: a 2km run and a 30km desert march. Strains were measured using strain-gauged staples inserted percutaneously in the medial aspect of their mid-tibial diaphysis. There was a decrease in the peak gastrocnemius isokinetic torque of all four subjects' post-march as compared to pre-run (p=0.0001), indicating the presence of gastrocnemius muscle fatigue. Tension strains increased 26% post-run (p=0.002, 95 % confidence interval (CI) and 29% post-march (p=0.0002, 95% CI) as compared to the pre-run phase. Tension strain rates increased 13% post-run (p=0.001, 95% CI) and 11% post-march (p=0.009, 95% CI) and the compression strain rates increased 9% post-run (p=0.0004, 95% CI) and 17% post-march (p=0.0001, 95% CI). The fatigue state increases bone strains well above those recorded in rested individuals and may be a major factor in the stress fracture etiology.

  19. Gender differences in passive knee biomechanical properties in tibial rotation.

    PubMed

    Park, Hyung-Soon; Wilson, Nicole A; Zhang, Li-Qun

    2008-07-01

    The anterior cruciate ligament (ACL) is the most commonly injured knee ligament with the highest incidence of injury in female athletes who participate in pivoting sports. Noncontact ACL injuries commonly occur with both internal and external tibial rotation. ACL impingement against the lateral wall of the intercondylar notch during tibial external rotation and abduction has been proposed as an injury mechanism, but few studies have evaluated in vivo gender-specific differences in laxity and stiffness in external and internal tibial rotations. The purpose of this study was to evaluate these differences. The knees of 10 male and 10 female healthy subjects were rotated between internal and external tibial rotation with the knee at 60 degrees of flexion. Joint laxity, stiffness, and energy loss were compared between male and female subjects. Women had higher laxity (p = 0.01), lower stiffness (p = 0.038), and higher energy loss (p = 0.008) in external tibial rotation than did men. The results suggest that women may be at greater risk of ACL injury resulting from impingement against the lateral wall of the intercondylar notch, which has been shown to be associated with external tibial rotation and abduction.

  20. The Capability of Fiber Bragg Grating Sensors to Measure Amputees' Trans-Tibial Stump/Socket Interface Pressures

    PubMed Central

    Al-Fakih, Ebrahim A.; Abu Osman, Noor Azuan; Eshraghi, Arezoo; Adikan, Faisal Rafiq Mahamd

    2013-01-01

    This study presents the first investigation into the capability of fiber Bragg grating (FBG) sensors to measure interface pressure between the stump and the prosthetic sockets of a trans-tibial amputee. FBG element(s) were recoated with and embedded in a thin layer of epoxy material to form a sensing pad, which was in turn embedded in a silicone polymer material to form a pressure sensor. The sensor was tested in real time by inserting a heavy-duty balloon into the socket and inflating it by using an air compressor. This test was conducted to examine the sensitivity and repeatability of the sensor when subjected to pressure from the stump of the trans-tibial amputee and to mimic the actual environment of the amputee's Patellar Tendon (PT) bar. The sensor exhibited a sensitivity of 127 pm/N and a maximum FSO hysteresis of around ∼0.09 in real-time operation. Very good reliability was achieved when the sensor was utilized for in situ measurements. This study may lead to smart FBG-based amputee stump/socket structures for pressure monitoring in amputee socket systems, which will result in better-designed prosthetic sockets that ensure improved patient satisfaction. PMID:23941909

  1. The capability of fiber Bragg grating sensors to measure amputees' trans-tibial stump/socket interface pressures.

    PubMed

    Al-Fakih, Ebrahim A; Osman, Noor Azuan Abu; Eshraghi, Arezoo; Adikan, Faisal Rafiq Mahamd

    2013-08-12

    This study presents the first investigation into the capability of fiber Bragg grating (FBG) sensors to measure interface pressure between the stump and the prosthetic sockets of a trans-tibial amputee. FBG element(s) were recoated with and embedded in a thin layer of epoxy material to form a sensing pad, which was in turn embedded in a silicone polymer material to form a pressure sensor. The sensor was tested in real time by inserting a heavy-duty balloon into the socket and inflating it by using an air compressor. This test was conducted to examine the sensitivity and repeatability of the sensor when subjected to pressure from the stump of the trans-tibial amputee and to mimic the actual environment of the amputee's Patellar Tendon (PT) bar. The sensor exhibited a sensitivity of 127 pm/N and a maximum FSO hysteresis of around ~0.09 in real-time operation. Very good reliability was achieved when the sensor was utilized for in situ measurements. This study may lead to smart FBG-based amputee stump/socket structures for pressure monitoring in amputee socket systems, which will result in better-designed prosthetic sockets that ensure improved patient satisfaction.

  2. Semiextended approach for intramedullary nailing via a patellar eversion technique for tibial-shaft fractures: Evaluation of the patellofemoral joint.

    PubMed

    Yasuda, Tomohiro; Obara, Shu; Hayashi, Junji; Arai, Masayuki; Sato, Kaoru

    2017-06-01

    Intramedullary nail fixation is a common treatment for tibial-shaft fractures, and it offers a better functional prognosis than other conservative treatments. Currently, the primary approach employed during intramedullary nail insertion is the semiextended position is the suprapatellar approach, which involves a vertical incision of the quadriceps tendon Damage to the patellofemoral joint cartilage has been highlighted as a drawback associated with this approach. To avoid this issue, we perform surgery using the patellar eversion technique and a soft sleeve. This method allows the articular surface to be monitored during intramedullary nail insertion. We arthroscopically assessed the effect of this technique on patellofemoral joint cartilage. The patellar eversion technique allows a direct view and protection of the patellofemoral joint without affecting the patella. Thus, damage to the patellofemoral joint cartilage can be avoided. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. The soleal line: a cause of tibial pseudoperiostitis.

    PubMed

    Levine, A H; Pais, M J; Berinson, H; Amenta, P S

    1976-04-01

    An unusually prominent soleal line (a normal anatomic variant) may mimic periosteal reaction along the posterior margin of the proximal tibial shaft. This area of pseudoperiostitis is differentiated from hyperostoses arising from the anterior tibial tubercle and the interosseous membrane. It is always associated with normal, undisturbed architecture of the underlying bone.

  4. Mobile-bearing total knee arthroplasty: a full traumatic rotation of 180°.

    PubMed

    Sudanese, Alessandra; Castiello, Emanuela; Affatato, Saverio

    2013-06-25

    From February 2008 to September 2012 we implanted 204 mobile-bearing knee prostheses in 192 patients. All the prostheses were cemented (both femoral and tibial components), and the patella was not replaced. Only one early complication of the implants (1/204 = 0.004%) occurred after a traumatic event as a full 180° rotation of the mobile-bearing polyethylene insert. A 78-year-old woman presented with swelling and severe pain at her right knee. This traumatic event was the only case among our mobile-bearing insert patients. 
The failed polyethylene inserts were retrieved and studied using a scanning electron microscope (SEM, ZEISS EVO 50 EP, Cambridge, UK) operating at 20 kV. 
Scratching and pitting were found on the UHMWPE insert perpendicular to the machining tracks for the concave surface. SEM micrographs of the insert showed burnishing on the concave surfaces and longitudinal scratches were clearly detectable and well-marked on the analyzed surfaces. 
A traumatic, fully rotating, polyethylene insert is rare and our case is the first report describing a traumatic event with a complete 180 degree rotation mobile-bearing in a total knee prosthesis. 
In the literature few reports discuss clinical outcomes after total knee arthroplasty in patients with Parkinson's disease and they cite mixed results. However, some authors suggest that posterior-stabilized and cruciate-retaining TKA should work well while others prefer cruciate-retaining, condylar constrained kinetics, or hinged devices. Although we did not implant a posterior-stabilized mobile-bearing total knee prosthesis or a constrained prosthesis, we obtained good clinical and radiological results at the 2-year followup.

  5. Tibial component considerations in bicruciate-retaining total knee arthroplasty: A 3D MRI evaluation of proximal tibial anatomy.

    PubMed

    Saxena, Vishal; Anari, Jason B; Ruutiainen, Alexander T; Voleti, Pramod B; Stephenson, Jason W; Lee, Gwo-Chin

    2016-08-01

    Restoration of normal anatomy and proper ligament balance are theoretical prerequisites for reproducing physiological kinematics with bicruciate-retaining total knee arthroplasty (TKA). The purpose of this study was to use a 3D MRI technique to evaluate the topography of the proximal tibia and outline considerations in tibial component design for bicruciate-retaining TKA. We identified 100 consecutive patients (50 males and 50 females) between ages 20 and 40 years with knee MRIs without arthritis, dysplasia, ACL tears, or prior knee surgery. A novel 3D MRI protocol coordinating axial, coronal, and sagittal images was used to measure: 1) medial and lateral posterior tibial slopes; 2) medial and lateral coronal slopes; and 3) distance from the anterior tibia to the ACL footprint. There was no overall difference in medial and lateral posterior tibial slopes (5.5° (95% CI 5.0 to 6.0°) vs. 5.4° (95% CI 4.8 to 6.0°), respectively (p=0.80)), but 41 patients had side-to-side differences greater than 3°. The medial coronal slope was greater than the lateral coronal slope (4.6° (95% CI 4.0 to 5.1°) vs. 3.3° (95% CI 2.9 to 3.7°), respectively (p<0.0001)). Females had less clearance between the anterior tibia and ACL footprint than males (10.8mm (95% CI 10.4 to 11.2mm) vs. 13.0mm (95% CI 12.5 to 13.5mm), respectively (p<0.0001)). Due to highly variable proximal tibial topography, a monoblock bicruciate-retaining tibial baseplate may not reproduce normal anatomy in all patients. Level IV - Anatomic research study. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Importance of tibial slope for stability of the posterior cruciate ligament deficient knee.

    PubMed

    Giffin, J Robert; Stabile, Kathryne J; Zantop, Thore; Vogrin, Tracy M; Woo, Savio L-Y; Harner, Christopher D

    2007-09-01

    Previous studies have shown that increasing tibial slope can shift the resting position of the tibia anteriorly. As a result, sagittal osteotomies that alter slope have recently been proposed for treatment of posterior cruciate ligament (PCL) injuries. Increasing tibial slope with an osteotomy shifts the resting position anteriorly in a PCL-deficient knee, thereby partially reducing the posterior tibial "sag" associated with PCL injury. This shift in resting position from the increased slope causes a decrease in posterior tibial translation compared with the PCL-deficient knee in response to posterior tibial and axial compressive loads. Controlled laboratory study. Three knee conditions were tested with a robotic universal force-moment sensor testing system: intact, PCL-deficient, and PCL-deficient with increased tibial slope. Tibial slope was increased via a 5-mm anterior opening wedge osteotomy. Three external loading conditions were applied to each knee condition at 0 degrees, 30 degrees, 60 degrees, 90 degrees, and 120 degrees of knee flexion: (1) 134-N anterior-posterior (A-P) tibial load, (2) 200-N axial compressive load, and (3) combined 134-N A-P and 200-N axial loads. For each loading condition, kinematics of the intact knee were recorded for the remaining 5 degrees of freedom (ie, A-P, medial-lateral, and proximal-distal translations, internal-external and varus-valgus rotations). Posterior cruciate ligament deficiency resulted in a posterior shift of the tibial resting position to 8.4 +/- 2.6 mm at 90 degrees compared with the intact knee. After osteotomy, tibial slope increased from 9.2 degrees +/- 1.0 degrees in the intact knee to 13.8 degrees +/- 0.9 degrees. This increase in slope reduced the posterior sag of the PCL-deficient knee, shifting the resting position anteriorly to 4.0 +/- 2.0 mm at 90 degrees. Under a 200-N axial compressive load with the osteotomy, an additional increase in anterior tibial translation to 2.7 +/- 1.7 mm at 30 degrees was

  7. Tibial shaft fractures in football players

    PubMed Central

    Chang, Winston R; Kapasi, Zain; Daisley, Susan; Leach, William J

    2007-01-01

    Background Football is officially the most popular sport in the world. In the UK, 10% of the adult population play football at least once a year. Despite this, there are few papers in the literature on tibial diaphyseal fractures in this sporting group. In addition, conflicting views on the nature of this injury exist. The purpose of this paper is to compare our experience of tibial shaft football fractures with the little available literature and identify any similarities and differences. Methods and Results A retrospective study of all tibial football fractures that presented to a teaching hospital was undertaken over a 5 year period from 1997 to 2001. There were 244 tibial fractures treated. 24 (9.8%) of these were football related. All patients were male with a mean age of 23 years (range 15 to 29) and shin guards were worn in 95.8% of cases. 11/24 (45.8%) were treated conservatively, 11/24 (45.8%) by Grosse Kemp intramedullary nail and 2/24 (8.3%) with plating. A difference in union times was noted, conservative 19 weeks compared to operative group 23.9 weeks (p < 0.05). Return to activity was also different in the two groups, conservative 27.6 weeks versus operative 23.3 weeks (p < 0.05). The most common fracture pattern was AO Type 42A3 in 14/24 (58.3%). A high number 19/24 (79.2%) were simple transverse or short oblique fractures. There was a low non-union rate 1/24 (4.2%) and absence of any open injury in our series. Conclusion Our series compared similarly with the few reports available in the literature. However, a striking finding noted by the authors was a drop in the incidence of tibial shaft football fractures. It is likely that this is a reflection of recent compulsory FIFA regulations on shinguards as well as improvements in the design over the past decade since its introduction. PMID:17567522

  8. Tibial Bowing and Pseudarthrosis in Neurofibromatosis Type 1

    DTIC Science & Technology

    2014-04-01

    Neurofibromatosis Type 1 PRINCIPAL INVESTIGATOR: Dr. David Stevenson CONTRACTING ORGANIZATION: University of Utah SALT LAKE CITY...COVERED 1 April 2013 - 31 March 2014 4. TITLE AND SUBTITLE Tibial Bowing and Pseudarthrosis in Neurofibromatosis Type 1 5a. CONTRACT NUMBER...SUPPLEMENTARY NOTES 14. ABSTRACT Anterolateral tibial bowing is a morbid skeletal manifestation observed in 5% of children with neurofibromatosis

  9. Comparison of volumetric bone mineral density in the tibial region of interest for ACL reconstruction.

    PubMed

    Klein, Scott A; Nyland, John; Caborn, David N M; Kocabey, Yavuz; Nawab, Akbar

    2005-12-01

    Adequate tibial bone mineral density (BMD) is essential to soft tissue graft fixation during anterior cruciate ligament (ACL) reconstruction. The purpose of this study was to compare volumetric bone plug density measurements at the tibial region of interest for ACL reconstruction using a standardized immersion technique and Archimedes' principle. Cancellous bone cores were harvested from the proximal, middle, and distal metaphyseal regions of the lateral tibia and from the standard tibial tunnel location used for ACL reconstruction of 18 cadaveric specimens. Proximal tibial cores displayed 32.6% greater BMD than middle tibial cores and 31.8% greater BMD than distal tibial cores, but did not differ from the BMD of the tibial tunnel cores. Correlational analysis confirmed that the cancellous BMD in the tibial tunnel related to the cancellous BMD of the proximal and distal lateral tibial metaphysis. In conjunction with its adjacent cortical bone, the cancellous BMD of the region used for standard tibial tunnel placement provides an effective foundation for ACL graft fixation. In tibia with poor BMD, bicortical fixation that incorporates cortical bone from the distal tibial tunnel region is recommended.

  10. Cranial tibial thrust: a primary force in the canine stifle.

    PubMed

    Slocum, B; Devine, T

    1983-08-15

    A cranially directed force identified within the canine stifle joint was termed cranial tibial thrust. It was generated during weight bearing by tibial compression, of which the tarsal tendon of the biceps femoris is a major contributor, and by the slope of the tibial plateau, found to have a mean cranially directed inclination of 22.6 degrees. This force may be an important factor in cranial cruciate ligament rupture and in generation of cranial drawer sign.

  11. [Tibiocalcaneal arthrodesis using retrograde insertion of a compression nail].

    PubMed

    Bölderl, A; Dallapozza, C; Wille, M

    2011-12-01

    OPERATION GOAL: Arthrodesis of the upper and lower ankle joint because of problematic bone positioning or failed arthrodesis. Osteosynthesis procedure using a retrograde compression nail. To achieve stable, fully weight-bearing osteosynthesis for early, pain-free mobilization. Rearthrodesis because of failure of the conventional arthrodesis technique and development of osteoarthritis of the lower ankle joint. Painful osteoarthritis of the upper ankle joint because of inadequate perfusion or a major bone defect because of sclerosis or necrosis. Primary arthrodesis because of facture of the lower leg (pilon tibial) with joint involvement and preexisting osteoarthritis. Acute osteitis/osteomyelitis, sclerosis in the marrow of the distal tibia, malalignment of the distal tibial shaft and local soft tissue inflammation. Preparation of the articular surface of the upper and lower ankle for arthrodesis using a transfibular approach. If necessary, correction of bone defects with iliac crest spongiosa. Stabile osteosynthesis by retrograde insertion of a compression nail. A split lower leg cast on the 2nd postoperative day, mobilization of the patient with underarm crutches with floor contact for 2 weeks, then with application of a lower leg walking cast for 8 weeks with partial weight-bearing for 4 weeks and full weight-bearing for the last 4 weeks of cast fixation. X-ray controls immediately postoperatively, then after 6 and 12 weeks. From 2006 to 2008, 12 patients (7 men, 5 women; mean age 59 years) with various indications were treated with retrograde insertion of a compression nail. All patients were routinely controlled radiologically and clinically after 2, 4, 8 and 12 weeks. Follow-up was carried out at 6, 12 and 24 months. All arthrodeses showed osseous consolidation 16 weeks postoperatively. Ten patients were able to use full weight-bearing without pain after 12 weeks. Two patients reported experiencing pain after walking for 2 h. In total three

  12. Tibial component coverage based on bone mineral density of the cut tibial surface during unicompartmental knee arthroplasty: clinical relevance of the prevention of tibial component subsidence.

    PubMed

    Lee, Yong Seuk; Yun, Ji Young; Lee, Beom Koo

    2014-01-01

    An optimally implanted tibial component during unicompartmental knee arthroplasty would be flush with all edges of the cut tibial surface. However, this is often not possible, partly because the tibial component may not be an ideal shape or because the ideal component size may not be available. In such situations, surgeons need to decide between component overhang and underhang and as to which sites must be covered and which sites could be undercovered. The objectives of this study were to evaluate the bone mineral density of the cut surface of the proximal tibia around the cortical rim and to compare the bone mineral density according to the inclusion of the cortex and the site-specific matched evaluation. One hundred and fifty consecutive patients (100 men and 50 women) were enrolled in this study. A quantitative computed tomography was used to determine the bone density of the cut tibial surface. Medial and lateral compartments were divided into anterior, middle, and posterior regions, and these three regions were further subdivided into two regions according to containment of cortex. The site-specific matched comparison (medial vs. lateral) of bone mineral density was performed. In medial sides, the mid-region, including the cortex, showed the highest bone mineral density in male and female patients. The posterior region showed the lowest bone mineral density in male patients, and the anterior and posterior regions showed the lowest bone mineral density in female patients. Regions including cortex showed higher bone mineral density than pure cancellous regions in medial sides. In lateral sides, posterior regions including cortex showed highest bone mineral density with statistical significance in both male and female patients. The anterior region showed the lowest bone mineral density in both male and female patients. The mid-region of the medial side and the posterior region of the lateral side are relatively safe without cortical coverage when the component

  13. Total knee arthroplasty and fractures of the tibial plateau

    PubMed Central

    Softness, Kenneth A; Murray, Ryan S; Evans, Brian G

    2017-01-01

    Tibial plateau fractures are common injuries that occur in a bimodal age distribution. While there are various treatment options for displaced tibial plateau fractures, the standard of care is open reduction and internal fixation (ORIF). In physiologically young patients with higher demand and better bone quality, ORIF is the preferred method of treating these fractures. However, future total knee arthroplasty (TKA) is a consideration in these patients as post-traumatic osteoarthritis is a common long-term complication of tibial plateau fractures. In older, lower demand patients, ORIF is potentially less favorable for a variety of reasons, namely fixation failure and the need for delayed weight bearing. In some of these patients, TKA can be considered as primary mode of treatment. This paper will review the literature surrounding TKA as both primary treatment and as a salvage measure in patients with fractures of the tibial plateau. The outcomes, complications, techniques and surgical challenges are also discussed. PMID:28251061

  14. Development of a Robust Static Punch Experiment for Screening Unprocessed Ultra-High Molecular Weight Polyethylene (UHMWPE) Unidirectional Cross-Ply Material

    DTIC Science & Technology

    2014-09-01

    Cross-Ply Material by David Gray, Robert Kaste , and Paul Moy ARL-TR-7090 September 2014...Screening Unprocessed Ultra-High Molecular Weight Polyethylene (UHMWPE) Unidirectional Cross-Ply Material David Gray, Robert Kaste , and Paul...ELEMENT NUMBER 6. AUTHOR(S) David Gray, Robert Kaste , and Paul Moy 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7

  15. Can the tibial slope be measured on lateral knee radiographs?

    PubMed

    Faschingbauer, M; Sgroi, M; Juchems, M; Reichel, H; Kappe, T

    2014-12-01

    The posterior tibial slope influences both the natural knee stability as well as the stability and kinematics after total knee arthroplasty (TKA). Exact definition of the posterior tibial slope (PTS) requires lateral radiographs of the lower limb. Only lateral knee radiographs are routinely obtained after TKA, however. The purpose of the present study therefore was to analyse the relationship between PTS measurement results on short and expanded lateral knee radiographs. The PTS was measured on 100 consecutive lateral radiographs of the lower limb using the mechanical and three diaphyseal axes with various distances below the tibial plateau. Significant differences between PTS results were found for all three diaphyseal axes, with the smallest differences and the strongest correlation for a diaphyseal axis at 16 and 20 cm below the tibial plateau. Using short distances below the tibial plateau (6 and 10 cm) resulted in an overestimation of the PTS of 3°, on average. The PTS measurements in long lateral knee radiographs are more accurate compared to short radiographs. On short lateral knee radiographs, only a estimation of the PTS can be carried out. Diagnostic study, Level II.

  16. Using a surrogate contact pair to evaluate polyethylene wear in prosthetic knee joints.

    PubMed

    Sanders, Anthony P; Lockard, Carly A; Weisenburger, Joel N; Haider, Hani; Raeymaekers, Bart

    2016-01-01

    With recent improvements to the properties of ultra-high molecular weight polyethylene (UHMWPE) used in joint replacements, prosthetic knee and hip longevity may extend beyond two decades. However, it is difficult and costly to replicate such a long in vivo lifetime using clinically relevant in vitro wear testing approaches such as walking gait joint simulators. We advance a wear test intermediate in complexity between pin-on-disk and knee joint simulator tests. The test uses a surrogate contact pair, consisting of a surrogate femoral and tibial specimen that replicate the contact mechanics of any full-scale knee condyle contact pair. The method is implemented in a standard multi-directional pin-on-disk wear test machine, and we demonstrate its application via a two-million-cycle wear test of three different UHMWPE formulations. Further, we demonstrate the use of digital photography and image processing to accurately quantify fatigue damage based on the reduced transmission of light through a damage area in a UHMWPE specimen. The surrogate contact pairs replicate the knee condyle contact areas within -3% to +12%. The gravimetric wear test results reflect the dose of crosslinking radiation applied to the UHMWPE: 35 kGy yielded a wear rate of 7.4 mg/Mcycles, 55 kGy yielded 1.0 mg/Mcycles, and 75 kGy (applied to a 0.1% vitamin E stabilized UHMWPE) yielded 1.5 mg/Mcycles. A precursor to spalling fatigue is observed and precisely measured in the radiation-sterilized (35 kGy) and aged UHMWPE specimen. The presented techniques can be used to evaluate the high-cycle fatigue performance of arbitrary knee condyle contact pairs under design-specific contact stresses, using existing wear test machines. This makes the techniques more economical and well-suited to standardized comparative testing. © 2015 Wiley Periodicals, Inc.

  17. External fixation of tibial pilon fractures and fracture healing.

    PubMed

    Ristiniemi, Jukka

    2007-06-01

    Distal tibial fractures are rare and difficult to treat because the bones are subcutaneous. External fixation is commonly used, but the method often results in delayed union. The aim of the present study was to find out the factors that affect fracture union in tibial pilon fractures. For this purpose, prospective data collection of tibial pilon fractures was carried out in 1998-2004, resulting in 159 fractures, of which 83 were treated with external fixation. Additionally, 23 open tibial fractures with significant > 3 cm bone defect that were treated with a staged method in 2000-2004 were retrospectively evaluated. The specific questions to be answered were: What are the risk factors for delayed union associated with two-ring hybrid external fixation? Does human recombinant BMP-7 accelerate healing? What is the role of temporary ankle-spanning external fixation? What is the healing potential of distal tibial bone loss treated with a staged method using antibiotic beads and subsequent autogenous cancellous grafting compared to other locations of the tibia? The following risk factors for delayed healing after external fixation were identified: post-reduction fracture gap of >3 mm and fixation of the associated fibula fracture. Fracture displacement could be better controlled with initial temporary external fixation than with early definitive fixation, but it had no significant effect on healing time, functional outcome or complication rate. Osteoinduction with rhBMP-7 was found to accelerate fracture healing and to shorten the sick leave. A staged method using antibiotic beads and subsequent autogenous cancellous grafting proved to be effective in the treatment of tibial bone loss. Healing potential of the bone loss in distal tibia was at least equally good as in other locations of the tibia.

  18. Posterior tibial slope as a risk factor for anterior cruciate ligament rupture in soccer players.

    PubMed

    Senişik, Seçkin; Ozgürbüz, Cengizhan; Ergün, Metin; Yüksel, Oğuz; Taskiran, Emin; Işlegen, Cetin; Ertat, Ahmet

    2011-01-01

    Anterior cruciate ligament (ACL) is the primary stabilizer of the knee. An impairment of any of the dynamic or static stability providing factors can lead to overload on the other factors and ultimately to deterioration of knee stability. This can result in anterior tibial translation and rupture of the ACL. The purpose of this study was to examine the influence of tibial slope on ACL injury risk on soccer players. A total of 64 elite soccer players and 45 sedentary controls were included in this longitudinal and controlled study. The angle between the tibial mid-diaphysis line and the line between the anterior and posterior edges of the medial tibial plateau was measured as the tibial slope via lateral radiographs. Individual player exposure, and injuries sustained by the participants were prospectively recorded. Eleven ACL injuries were documented during the study period. Tibial slope was not different between soccer players and sedentary controls. Tibial slope in the dominant and non-dominant legs was greater for the injured players compared to the uninjured players. The difference reached a significant level only for the dominant legs (p < 0.001). While the tibial slopes of the dominant and non-dominant legs were not different on uninjured players (p > 0.05), a higher tibial slope was observed in dominant legs of injured players (p < 0.05). Higher tibial slope on injured soccer players compared to the uninjured ones supports the idea that the tibial slope degree might be an important risk factor for ACL injury. Key pointsDominant legs' tibial slopes of the injured players were significantly higher compared to the uninjured players (p < 0.001).Higher tibial slope was determined in dominant legs compared to the non-dominant side, for the injured players (p = 0.042). Different tibial slope measures in dominant and non-dominant legs might be the result of different loading and/or adaptation patterns in soccer.

  19. MRI Anatomy of the Tibial ACL Attachment and Proximal Epiphysis in a Large Population of Skeletally Immature Knees: Reference Parameters for Planning Anatomic Physeal-Sparing ACL Reconstruction.

    PubMed

    Swami, Vimarsha Gopal; Mabee, Myles; Hui, Catherine; Jaremko, Jacob Lester

    2014-07-01

    To aid in performing anatomic physeal-sparing anterior cruciate ligament (ACL) reconstruction, it is important for surgeons to have reference data for the native ACL attachment positions and epiphyseal anatomy in skeletally immature knees. To characterize anatomic parameters of the ACL tibial insertion and proximal tibial epiphysis at magnetic resonance imaging (MRI) in a large population of skeletally immature knees. Cross-sectional study; Level of evidence, 3. The ACL tibial attachment site and proximal epiphysis were examined in 570 skeletally immature knees with an intact ACL (age, 6-15 years) using 1.5-T proton density-weighted sagittal MRI; also measured were the tibial anteroposterior diameter; anterior, central, and posterior ACL attachment positions; vertical height of the epiphysis; and maximum oblique epiphyseal depth extending from the ACL tibial attachment center to the tibial tuberosity. In adolescents (11-15 years of age), the center of the ACL's tibial attachment was 51.5% ± 5.7% of the anteroposterior diameter of the tibia, with no significant differences between sexes or age groups (P > .05 in all cases). Mean vertical epiphyseal height was 15.9 ± 1.7 mm in the adolescent group, with significant differences between 11-year-olds (15.2 ± 1.5 mm) and 15-year-olds (16.6 ± 1.6 mm), P < .001, and between males (16.6 ± 1.5 mm) and females (14.8 ± 1.4), P < .001. Mean maximum oblique depth was 30.0 ± 5.3 mm, with a significant difference between 11-year-olds (26.7 ± 4.9 mm) and 15-year-olds (32.7 ± 5.1 mm), P < .001, and between males (29.7 ± 6.4 mm) and females (27.8 ± 5.2 mm), P < .001. The maximum oblique depth occurred at a mean angle of ~50°, and this angle did not change with age or sex. There was a significant moderate correlation (r = 0.39, P < .001) between epiphyseal vertical height and maximum oblique depth. The center of the ACL tibial attachment was consistently near 51% of the anteroposterior diameter, regardless of age or sex

  20. Primary Ankle Arthrodesis for Severely Comminuted Tibial Pilon Fractures.

    PubMed

    Al-Ashhab, Mohamed E

    2017-03-01

    Management of severely comminuted, complete articular tibial pilon fractures (Rüedi and Allgöwer type III) remains a challenge, with few treatment options providing good clinical outcomes. Twenty patients with severely comminuted tibial pilon fractures underwent primary ankle arthrodesis with a retrograde calcaneal nail and autogenous fibular bone graft. The fusion rate was 100% and the varus malunion rate was 10%. Fracture union occurred at a mean of 16 weeks (range, 13-18 weeks) postoperatively. Primary ankle arthrodesis is a successful method for treating highly comminuted tibial pilon fractures, having a low complication rate and a high satisfaction score. [Orthopedics. 2017; 40(2):e378-e381.]. Copyright 2016, SLACK Incorporated.

  1. 21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint tibial (hemi-knee) metallic resurfacing... Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis is a device intended to be implanted...

  2. All-Polyethylene Tibial Components: An Analysis of Long-Term Outcomes and Infection.

    PubMed

    Houdek, Matthew T; Wagner, Eric R; Wyles, Cody C; Watts, Chad D; Cass, Joseph R; Trousdale, Robert T

    2016-07-01

    There is debate regarding tibial component modularity and composition in total knee arthroplasty (TKA). Biomechanical studies have suggested improved stress distribution in metal-backed tibias; however, these results have not translated clinically. The purpose of this study was to analyze the outcomes of all-polyethylene components and to compare the results to those with metal-backed components. We reviewed 31,939 patients undergoing a primary TKA over a 43-year period (1970-2013). There were 28,224 (88%) metal-backed and 3715 (12%) all-polyethylene tibial components. The metal-backed and all-polyethylene groups had comparable demographics with respect to gender, age and body mass index (BMI). Mean follow-up was 7 years. The mean survival for all primary TKAs at the 5-, 10-, 20- and 30-year time points was 95%, 89%, 73%, and 57%, respectively. All-polyethylene tibial components were found to have a significantly improved (P < .0001) survivorship when compared with their metal-backed counterparts. All-polyethylene tibial components were also found to have a significantly lower rate of infection, instability, tibial component loosening, and periprosthetic fracture. The all-polyethylene group had improved survival rates in all age groups, except in patients 85 years old or greater, where there was no significant difference. All-polyethylene tibial components had improved survival for all BMI groups except in the morbidly obese (BMI ≥ 40) where there was no significant difference. All-polyethylene tibial components had significantly improved implant survival, reduced rates of postoperative infection, fracture, and tibial component loosening. All polyethylene should be considered for most of the patients, regardless of age and BMI. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Complex Medial Meniscus Tears Are Associated With a Biconcave Medial Tibial Plateau.

    PubMed

    Barber, F Alan; Getelman, Mark H; Berry, Kathy L

    2017-04-01

    To determine whether an association exists between a biconcave medial tibial plateau and complex medial meniscus tears. A consecutive series of stable knees undergoing arthroscopy were evaluated retrospectively with the use of preoperative magnetic resonance imaging (MRI), radiographs, and arthroscopy documented by intraoperative videos. Investigators independently performed blinded reviews of the MRI or videos. Based on the arthroscopy findings, medial tibial plateaus were classified as either biconcave or not biconcave. A transverse coronal plane ridge, separating the front of the tibial plateau from the back near the inner margin of the posterior body of the medial meniscus, was defined as biconcave. The medial plateau slope was calculated with MRI sagittal views. General demographic information, body mass index, and arthroscopically confirmed knee pathology were recorded. A total of 179 consecutive knees were studied from July 2014 through August 2015; 49 (27.2%) biconcave medial tibial plateaus and 130 (72.8%) controls were identified at arthroscopy. Complex medial meniscus tears were found in 103. Patients with a biconcave medial tibial plateau were found to have more complex medial meniscus tears (69.4%) than those without a biconcavity (53.1%) (P = .049) despite having lower body mass index (P = .020). No difference in medial tibial plateau slope was observed for biconcavities involving both cartilage and bone, bone only, or an indeterminate group (P = .47). Biconcave medial tibial plateaus were present in 27.4% of a consecutive series of patients undergoing knee arthroscopy. A biconcave medial tibial plateau was more frequently associated with a complex medial meniscus tear. Level III, case-control study. Copyright © 2016 Arthroscopy Association of North America. All rights reserved.

  4. Total knee replacement-cementless tibial fixation with screws: 10-year results.

    PubMed

    Ersan, Önder; Öztürk, Alper; Çatma, Mehmet Faruk; Ünlü, Serhan; Akdoğan, Mutlu; Ateş, Yalım

    2017-12-01

    The aim of this study was to evaluate the long term clinical and radiological results of cementless total knee replacement. A total of 51 knees of 49 patients (33 female and 16 male; mean age: 61.6 years (range, 29-66 years)) who underwent TKR surgery with a posterior stabilized hydroxyapatite coated knee implant were included in this study. All of the tibial components were fixed with screws. The HSS scores were examined preoperatively and at the final follow-up. Radiological assessment was performed with Knee Society evaluating and scoring system. Kaplan-Meier survival analysis was performed to rule out the survival of the tibial component. The mean HSS scores were 45.8 (range 38-60) and 88.1 (range 61-93), preoperatively and at the final follow-up respectively. Complete radiological assessment was performed for 48 knees. Lucent lines at the tibial component were observed in 4 patients; one of these patients underwent a revision surgery due to the loosening of the tibial component. The 10-year survival rate of a tibial component was 98%. Cementless total knee replacement has satisfactory long term clinical results. Primary fixation of the tibial component with screws provides adequate stability even in elderly patients with good bone quality. Level IV, Therapeutic study. Copyright © 2017 Turkish Association of Orthopaedics and Traumatology. Production and hosting by Elsevier B.V. All rights reserved.

  5. Modified arthroscopic suture fixation of a displaced tibial eminence fracture.

    PubMed

    Lehman, Ronald A; Murphy, Kevin P; Machen, M Shaun; Kuklo, Timothy R

    2003-02-01

    This study describes a new arthroscopic method using a whip-stitch technique for treating a displaced type III tibial eminence fracture. A 12-year-old girl who sustained a displaced type III tibial eminence fracture was treated with arthroscopic fixation using the Arthrosew disposable suture device (Surgical Dynamics, Norwalk, CT) to place a whip stitch into the anterior cruciate ligament (ACL). The Arthrex ACL guide (Arthrex, Naples, FL) was used to reduce the avulsed tibial spine fragment. Sutures were then passed through the tibial tunnel and secured over a bony bridge with the knee in 20 degrees of flexion. At 9 months, the patient has a full range of motion with normal Lachman and anterior drawer testing, and she has returned to competitive basketball. Radiographs show complete fracture healing. KT-1000 and isokinetic testing at 9-month follow-up show only minimal side-to-side differences. The Arthrosew device provides a significant advantage in the treatment of type III and IV fractures of the tibial eminence by obtaining arthroscopic fixation within the substance of the ACL, thus obviating arthrotomy and hardware placement. This technique also restores the proper length and tension to the ACL, and provides a simplified, reproducible method of treatment for this injury.

  6. Anterior tibial stress fractures treated with anterior tension band plating in high-performance athletes.

    PubMed

    Cruz, Alexandre Santa; de Hollanda, João Paris Buarque; Duarte, Aires; Hungria Neto, José Soares

    2013-06-01

    The non-surgical treatment of anterior tibial cortex stress fractures requires long periods of abstention from sports activities and often results in non-union. Many different surgical techniques have already been previously described to treat these fractures, but there is no consensus on the best treatment. We describe the outcome of treatment using anterior tibial tension band plating in three high-performance athletes (4 legs) with anterior tibial cortex stress fractures. Tibial osteosynthesis with a 3.5-mm locking compression plate in the anterolateral aspect of the tibia was performed in all patients diagnosed with anterior tibial stress fracture after September 2010 at Santa Casa Hospital. All of the fractures were consolidated within a period of 3 months after surgery, allowing for an early return to pre-injury levels of competitive sports activity. There were no infection, non-union, malunion or anterior knee pain complications. Anterior tibial tension band plating leads to prompt fracture consolidation and is a good alternative for the treatment of anterior tibial cortex stress fractures. Bone grafts were shown to be unnecessary.

  7. Metal-backed versus all-polyethylene tibial components in primary total knee arthroplasty

    PubMed Central

    2011-01-01

    Background and purpose The choice of either all-polyethylene (AP) tibial components or metal-backed (MB) tibial components in total knee arthroplasty (TKA) remains controversial. We therefore performed a meta-analysis and systematic review of randomized controlled trials that have evaluated MB and AP tibial components in primary TKA. Methods The search strategy included a computerized literature search (Medline, EMBASE, Scopus, and the Cochrane Central Register of Controlled Trials) and a manual search of major orthopedic journals. A meta-analysis and systematic review of randomized or quasi-randomized trials that compared the performance of tibial components in primary TKA was performed using a fixed or random effects model. We assessed the methodological quality of studies using Detsky quality scale. Results 9 randomized controlled trials (RCTs) published between 2000 and 2009 met the inclusion quality standards for the systematic review. The mean standardized Detsky score was 14 (SD 3). We found that the frequency of radiolucent lines in the MB group was significantly higher than that in the AP group. There were no statistically significant differences between the MB and AP tibial components regarding component positioning, knee score, knee range of motion, quality of life, and postoperative complications. Interpretation Based on evidence obtained from this study, the AP tibial component was comparable with or better than the MB tibial component in TKA. However, high-quality RCTs are required to validate the results. PMID:21895503

  8. Effect of tibial plateau leveling on stability of the canine cranial cruciate-deficient stifle joint: an in vitro study.

    PubMed

    Reif, Ullrich; Hulse, Donald A; Hauptman, Joe G

    2002-01-01

    To evaluate the effect of tibial plateau leveling on joint motion in canine stifle joints in which the cranial cruciate ligament (CCL) had been severed. In vitro cadaver study. Six canine cadaver hind legs. Radiographs of the stifle joints were made to evaluate the tibial plateau angle with respect to the long axis of the tibia. The specimens were mounted in a custom-made testing device to measure cranio-caudal translation of the tibia with respect to the femur. An axial load was applied to the tibia, and its position was recorded in the normal stifle, after transection of the CCL, and after tibial plateau leveling. Further, the amount of caudal tibial thrust was measured in the tibial plateau leveled specimen while series of eight linearly increasing axial tibial loads were applied. Transection of the CCL resulted in cranial tibial translation when axial tibial load was applied. After tibial plateau leveling, axial loading resulted in caudal translation of the tibia. Increasing axial tibial load caused a linear increase in caudal tibial thrust in all tibial plateau-leveled specimens. After tibial plateau leveling, axial tibial load generates caudal tibial thrust, which increases if additional axial load is applied. Tibial plateau leveling osteotomy may prevent cranial translation during weight bearing in dogs with CCL rupture by converting axial load into caudal tibial thrust. The amount of caudal tibial thrust seems to be proportional to the amount of weight bearing. Copyright 2002 by The American College of Veterinary Surgeons

  9. Biotribological behavior of Ag-ZrCxN1-x coatings against UHMWPE for joint prostheses devices.

    PubMed

    Calderon V, S; Sánchez-López, J C; Cavaleiro, A; Carvalho, S

    2015-01-01

    This study aims to evaluate the structural, mechanical and tribological properties of zirconium carbonitrides (ZrCxN1-x) coatings with embedded silver nanoparticles, produced with the intention of achieving a material with enhanced multi-functional properties, including mechanical strength, corrosion resistance, tribological performance and antibacterial behavior suitable for their use in joint prostheses. The coatings were deposited by direct current (DC) reactive magnetron sputtering onto 316 L stainless steel, changing the silver content from 0 to 20 at% by modifying the current density applied to the targets. Different nitrogen and acetylene gas fluxes were used as reactive gases. The coatings revealed different mixtures of crystalline ZrCxN1-x, silver nanoparticles and amorphous carbon phases. The hardness of the films was found to be mainly controlled by the ratio between the hard (ZrCxN1-x) and soft (Ag and amorphous carbon) phases in the films, fluctuating between 7.4 and 20.4 GPa. The coefficient of friction, measured against ultra-high molecular weight polyethylene (UHMWPE) in Hank's balanced salt solution with 10 gL(-1) albumin, is governed by the surface roughness and hardness. The UHMWPE wear rates were in the same order of magnitude (between 1.4 and 2.0 × 10(-6)mm(3)N(-1)m(-1)), justified by the effect of the protective layer of albumin formed during the tests. The small differences were due to the hydrophobic/hydrophilic character of the surface, as well as to the silver content. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Measurement of bone adjacent to tibial shaft fracture.

    PubMed

    Findlay, S C; Eastell, R; Ingle, B M

    2002-12-01

    Delayed union and non-union are common complications after fracture of the tibial shaft. Response of the surrounding bone as a fracture heals could be monitored using techniques currently used in the study of osteoporosis. The aims of our study were to: (1) evaluate the decrement in bone measurements made close to the fracture using dual-energy X-ray absorptiometry (DXA), quantitative ultrasound (QUS) and peripheral quantitative computed tomography (pQCT); (2) compare values for fractured versus non-fractured leg to determine the duration of decrement in bone measurements; and (3) calculate short-term precision in DXA, QUS and pQCT in order to calculate the ratio of decrement to precision (response ratio, RR) to determine the optimal test for monitoring changes after tibial fracture. The biggest decrement in bone measurements at the ipsilateral limb of 28 patients with tibial shaft fracture was observed at the pQCT tibial trabecular sites (distal = 19%, p<0.0001; proximal 5% = 21%, p<0.001; proximal 10% = 28%, p<0.001) and the ultradistal tibia/fibula measured by DXA (19%, p<0.0001). When comparing Z-scores, the magnitude of decrements at the ipsilateral limb was bigger for variables measured directly at the tibia, both proximal and distal to the fracture. The magnitude of the decrement in ultradistal tibia/fibula BMD decreased as the time since fracture increased ( r = 0.55). When response ratios are considered, pQCT measurements at the distal tibia (RR 6-8) and proximal 5% and 10% trabecular sites (RR 5 and 9 respectively) were found to be the most sensitive to change. Therefore, pQCT of the trabecular regions of either the proximal or distal tibia should prove the most sensitive measurement for monitoring changes in bone adjacent to a tibial shaft fracture.

  11. Ground reaction forces and bone parameters in females with tibial stress fracture.

    PubMed

    Bennell, Kim; Crossley, Kay; Jayarajan, Jyotsna; Walton, Elizabeth; Warden, Stuart; Kiss, Z Stephen; Wrigley, Tim

    2004-03-01

    Tibial stress fracture is a common overuse running injury that results from the interplay of repetitive mechanical loading and bone strength. This research project aimed to determine whether female runners with a history of tibial stress fracture (TSF) differ in ground reaction force (GRF) parameters during running, regional bone density, and tibial bone geometry from those who have never sustained a stress fracture (NSF). Thirty-six female running athletes (13 TSF; 23 NSF) ranging in age from 18 to 44 yr were recruited for this cross-sectional study. The groups were well matched for demographic, training, and menstrual parameters. A force platform measured selected GRF parameters (peak and time to peak for vertical impact and active forces, and horizontal braking and propulsive forces) during overground running at 4.0 m.s.(-1). Lumbar spine, proximal femur, and distal tibial bone mineral density were assessed by dual energy x-ray absorptiometry. Tibial bone geometry (cross-sectional dimensions and areas, and second moments of area) was calculated from a computerized tomography scan at the junction of the middle and distal thirds. There were no significant differences between the groups for any of the GRF, bone density, or tibial bone geometric parameters (P > 0.05). Both TSF and NSF subjects had bone density levels that were average or above average compared with a young adult reference range. Factor analysis followed by discriminant function analysis did not find any combinations of variables that differentiated between TSF and NSF groups. These findings do not support a role for GRF, bone density, or tibial bone geometry in the development of tibial stress fractures, suggesting that other risk factors were more important in this cohort of female runners.

  12. Bone microarchitecture of the tibial plateau in skeletal health and osteoporosis.

    PubMed

    Krause, Matthias; Hubert, Jan; Deymann, Simon; Hapfelmeier, Alexander; Wulff, Birgit; Petersik, Andreas; Püschel, Klaus; Amling, Michael; Hawellek, Thelonius; Frosch, Karl-Heinz

    2018-05-07

    Impaired bone structure poses a challenge for the treatment of osteoporotic tibial plateau fractures. As knowledge of region-specific structural bone alterations is a prerequisite to achieving successful long-term fixation, the aim of the current study was to characterize tibial plateau bone structure in patients with osteoporosis and the elderly. Histomorphometric parameters were assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT) in 21 proximal tibiae from females with postmenopausal osteoporosis (mean age: 84.3 ± 4.9 years) and eight female healthy controls (45.5 ± 6.9 years). To visualize region-specific structural bony alterations with age, the bone mineral density (Hounsfield units) was additionally analyzed in 168 human proximal tibiae. Statistical analysis was based on evolutionary learning using globally optimal regression trees. Bone structure deterioration of the tibial plateau due to osteoporosis was region-specific. Compared to healthy controls (20.5 ± 4.7%) the greatest decrease in bone volume fraction was found in the medio-medial segments (9.2 ± 3.5%, p < 0.001). The lowest bone volume was found in central segments (tibial spine). Trabecular connectivity was severely reduced. Importantly, in the anterior and posterior 25% of the lateral and medial tibial plateaux, trabecular support and subchondral cortical bone thickness itself were also reduced. Thinning of subchondral cortical bone and marked bone loss in the anterior and posterior 25% of the tibial plateau should require special attention when osteoporotic patients require fracture fixation of the posterior segments. This knowledge may help to improve the long-term, fracture-specific fixation of complex tibial plateau fractures in osteoporosis. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Comparison of long-term results between osteo-odonto-keratoprosthesis and tibial bone keratoprosthesis.

    PubMed

    Charoenrook, Victor; Michael, Ralph; de la Paz, Maria Fideliz; Temprano, José; Barraquer, Rafael I

    2018-04-01

    To compare the anatomical and the functional results between osteo-odonto-keratoprosthesis (OOKP) and keratoprosthesis using tibial bone autograft (Tibial bone KPro). We reviewed the charts of 258 patients; 145 had OOKP whereas 113 had Tibial bone KPro implanted. Functional success was defined as best corrected visual acuity ≥0.05 on decimal scale and anatomical success as retention of the keratoprosthesis lamina. Kaplan-Meier survival curves were calculated for anatomical and functional survival as well as to estimate the probability of post-op complications. The anatomical survival for both KPro groups was not significantly different and was estimated as 67% for OOKP and 54% for Tibial bone KPro at 10 years after surgery. There was also no difference found after subdividing for primary diagnosis groups such as chemical injury, thermal burn, trachoma and all autoimmune cases combined. Estimated functional survival at 10 years post-surgery was 49% for OOKP and 25% for Tibial bone KPro, which was significantly different. The probability of patients with Tibial bone KPro developing one or more post-operative complications at 10 years after surgery (65%) was significantly higher than those with OOKP (40%). Mucous membrane necrosis and retroprosthetic membrane formation were more common in Tibial bone KPro than OOKP. Both types of autologous biological KPro, OOKP and Tibial bone KPro, had statistically similar rate of keratoprosthesis extrusion. Although functional success rate was significantly higher in OOKP, it may have been influenced by a better visual potential in the patients in this group. Copyright © 2018 Elsevier Inc. All rights reserved.

  14. Effect of tibial slope on the stability of the anterior cruciate ligament-deficient knee.

    PubMed

    Voos, James E; Suero, Eduardo M; Citak, Musa; Petrigliano, Frank P; Bosscher, Marianne R F; Citak, Mustafa; Wickiewicz, Thomas L; Pearle, Andrew D

    2012-08-01

    We aimed to quantify the effect of changes in tibial slope on the magnitude of anterior tibial translation (ATT) in the anterior cruciate ligament (ACL)-deficient knee during the Lachman and mechanized pivot shift tests. We hypothesized that increased posterior tibial slope would increase the amount of ATT of an ACL-deficient knee, while leveling the slope of the tibial plateau would decrease the amount of ATT. Lachman and mechanized pivot shift tests were performed on hip-to-toe cadaveric specimens, and ATT of the lateral and the medial compartments was measured using navigation (n = 11). The ACL was then sectioned. Stability testing was repeated, and ATT was recorded. A proximal tibial osteotomy in the sagittal plane was then performed achieving either +5 or -5° of tibial slope variation after which stability testing was repeated (n = 10). Sectioning the ACL resulted in a significant increase in ATT in both the Lachman and mechanized pivot shift tests (P < 0.05). Increasing or decreasing the slope of the tibial plateau had no effect on ATT during the Lachman test (n.s.). During the mechanized pivot shift tests, a 5° increase in posterior slope resulted in a significant increase in ATT compared to the native knee (P < 0.05), while a 5° decrease in slope reduced ATT to a level similar to that of the intact knee. Tibial slope changes did not affect the magnitude of translation during a Lachman test. However, large changes in tibial slope variation affected the magnitude of the pivot shift.

  15. Development of biomimetic in vitro fatigue assessment for UHMWPE implant materials.

    PubMed

    Scholz, Ronja; Knyazeva, Marina; Porchetta, Dario; Wegner, Nils; Senatov, Fedor; Salimon, Alexey; Kaloshkin, Sergey; Walther, Frank

    2018-05-26

    An important research goal in the field of biomaterials lies in the progressive amendment of in vivo tests with suitable in vitro experiments. Such approaches are gaining more significance nowadays because of an increasing demand on life sciences and the ethical issues bound to the sacrifice of animals for the sake of scientific research. Another advantage of transferring the experiments to the in vitro field is the possibility of accurately control the boundary conditions and experimental parameters in order to reduce the need of validation tests involving animals. With the aim to reduce the amount of needed in vivo studies for this cause, a short-time in vitro test procedure using instrumented load increase tests with superimposed environmental loading has been developed at TUD to assess the mechanical long-term durability of ultra-high molecular weight polyethylene (UHMWPE) under fatigue loading in a biological environment. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Effect of insertion torque on titanium implant osseointegration: an animal experimental study.

    PubMed

    Duyck, Joke; Roesems, Rutger; Cardoso, Marcio V; Ogawa, Toru; De Villa Camargos, Germana; Vandamme, Katleen

    2015-02-01

    To evaluate the effect of implant insertion torque on the peri-implant bone healing and implant osseointegration. Bilaterally in the tibia of five adult New Zealand white rabbits, 20 implants were installed, subdivided into four groups, corresponding to two insertion torque conditions (low, < 10 Ncm vs. high > 50 Ncm) and 2 experimental periods (2 weeks vs. 4 weeks of healing). The implant insertion torque was determined by the surgical drill diameter relative to the implant diameter. Implant osseointegration was evaluated by quantitative histology (bone-to-implant contact with host bone [BIC-host], with neoformed bone [BIC-de novo], with both bone types [BIC-total], and peri-implant bone [BA/TA]). Every response was modelled over time using GEE (general estimation equation) with an unstructured variance-covariance matrix to correct for dependency between the measurements from one animal. The statistical significance level of α = 0.05 was applied. Significantly, more BIC-host and BIC-total were recorded for H implants compared with L implants after 2 week of healing (P = 0.010 and P = 0.0001, respectively). However, this result was no longer found for the extended healing period. Furthermore, BIC-total significantly increased over time for L implants (P < 0.00001). In contrast, the significant increase in BA/TA over time was found for H implants (P < 0.01). Finally, H insertion torque led to an increased BA/TA after 4 week of healing (P < 0.02) compared with the L insertion protocol. L insertion torque implants installed in the rabbit tibial bone osseointegrate with considerable de novo bone formation. This bone neoformation enables L implants to catch up, already during the early osseointegration stage, the initial inferior amount BIC contact compared with that of H implants. A negative impact of the created strain environment accompanying H insertion torque implant installation on the biological process of osseointegration could not be observed, at least not at

  17. Tibial Acceleration and Spatiotemporal Mechanics in Distance Runners During Reduced-Body-Weight Conditions.

    PubMed

    Moran, Matthew F; Rickert, Brendan J; Greer, Beau K

    2017-05-01

    Treadmills that unload runners via a differential air-pressure (DAP) bladder (eg, AlterG Anti-Gravity Treadmill) are commonly used to reduce effective body weight (BW) in a clinical setting. However, the relationship between the level of unloading and tibial stress is currently unknown. To determine the relationship between tibial impact acceleration and level of BW unloading during running. Cross-sectional. University motion-analysis laboratory. 15 distance runners (9 male, 6 female; 20.4 ± 2.4 y, 60.1 ± 12.6 kg). Peak tibial acceleration and peak-to-peak tibial acceleration were measured via a uniaxial accelerometer attached to the tibia during a 37-min continuous treadmill run that simulated reduced-BW conditions via a DAP bladder. The trial began with a 10-min run at 100% BW followed by nine 3-min stages where BW was systematically reduced from 95% to 60% in 5% increments. There was no significant relationship between level of BW and either peak tibial acceleration or peak-to-peak tibial acceleration (P > .05). Both heart rate and step rate were significantly reduced with each 5% reduction in BW level (P < .01). Although ground-reaction forces are reduced when running in reduced-BW conditions on a DAP treadmill, tibial shock magnitudes are unchanged as an alteration in spatiotemporal running mechanics (eg, reduced step rate) and may nullify the unloading effect.

  18. The Effect of Tibial Plateau Levelling Osteotomy on Stifle Extensor Mechanism Load: A Canine Ex Vivo Study.

    PubMed

    Drew, Jarrod O; Glyde, Mark R; Hosgood, Giselle L; Hayes, Alex J

    2018-02-01

     To evaluate the effect of tibial plateau levelling osteotomy on stifle extensor mechanism load in an ex vivo cruciate-intact canine cadaveric model.   Ex vivo mechanical testing study.  Cadaveric canine pelvic limbs ( n  = 6).  A 21-mm tibial radial osteotomy was performed on pelvic limbs ( n  = 6) prior to being mounted into a load-bearing limb press. The proximal tibial segment was incrementally rotated until the anatomical tibial plateau angle had been rotated to at least 1°. The proportional change in stifle extensor mechanism load between the anatomical tibial plateau angle and the neutralized (∼6.5 degrees) and over-rotated (∼1°) tibial plateau angle was analysed using a one-sample t -test against a null hypothesis of no change. A p -value ≤0.05 was considered significant.  There was no significant change in the stifle extensor mechanism load from the anatomical tibial plateau angle (308 N [261-355 N]) to the neutralized tibial plateau angle (313 N [254-372 N]; p =.81), or from the anatomical tibial plateau angle to the over-rotated tibial plateau angle (303 N [254-352 N; p  = 0.67).  Tibial plateau levelling osteotomy does not significantly alter stifle extensor mechanism load at either a neutralized or over-rotated tibial plateau angle in our cruciate-intact model. Schattauer GmbH Stuttgart.

  19. [Magnetic resonance imaging of tibial periostitis].

    PubMed

    Meyer, X; Boscagli, G; Tavernier, T; Aczel, F; Weber, F; Legros, R; Charlopain, P; Martin, J P

    1998-01-01

    Tibial periostitis frequently occurs in athletes. We present our experience with MRI in a series of 7 patients (11 legs) with this condition. The clinical presentation and scintigraphic scanning suggested the diagnosis. MRI exploration of 11 legs demonstrated a high band-like juxta-osseous signal enhancement of SE and IR T2 weighted sequences in 6 cases, a signal enhancement after i.v. contrast administration in 4. Tibial periostitis is a clinical diagnosis and MRI and scintigraphic findings can be used to assure the differential diagnosis in difficult cases with stress fracture. MRI can visualize juxta-osseous edematous and inflammatory reactions and an increased signal would appear to be characteristic when the band-like image is fixed to the periosteum.

  20. Tibial component alignment and risk of loosening in unicompartmental knee arthroplasty: a radiographic and radiostereometric study.

    PubMed

    Barbadoro, P; Ensini, A; Leardini, A; d'Amato, M; Feliciangeli, A; Timoncini, A; Amadei, F; Belvedere, C; Giannini, S

    2014-12-01

    Unicompartmental knee arthroplasty (UKA) has shown a higher rate of revision compared with total knee arthroplasty. The success of UKA depends on prosthesis component alignment, fixation and soft tissue integrity. The tibial cut is the crucial surgical step. The hypothesis of the present study is that tibial component malalignment is correlated with its risk of loosening in UKA. This study was performed in twenty-three patients undergoing primary cemented unicompartmental knee arthroplasties. Translations and rotations of the tibial component and the maximum total point motion (MTPM) were measured using radiostereometric analysis at 3, 6, 12 and 24 months. Standard radiological evaluations were also performed immediately before and after surgery. Varus/valgus and posterior slope of the tibial component and tibial-femoral axes were correlated with radiostereometric micro-motion. A survival analysis was also performed at an average of 5.9 years by contacting patients by phone. Varus alignment of the tibial component was significantly correlated with MTPM, anterior tibial sinking, varus rotation and anterior and medial translations from radiostereometry. The posterior slope of the tibial component was correlated with external rotation. The survival rate at an average of 5.9 years was 89%. The two patients who underwent revision presented a tibial component varus angle of 10° for both. There is correlation between varus orientation of the tibial component and MTPM from radiostereometry in unicompartmental knee arthroplasties. Particularly, a misalignment in varus larger than 5° could lead to risk of loosening the tibial component. Prognostic studies-retrospective study, Level II.

  1. Influence of the posterior tibial slope on the flexion gap in total knee arthroplasty.

    PubMed

    Okazaki, Ken; Tashiro, Yasutaka; Mizu-uchi, Hideki; Hamai, Satoshi; Doi, Toshio; Iwamoto, Yukihide

    2014-08-01

    Adjusting the joint gap length to be equal in both extension and flexion is an important issue in total knee arthroplasty (TKA). It is generally acknowledged that posterior tibial slope affects the flexion gap; however, the extent to which changes in the tibial slope angle directly affect the flexion gap remains unclear. This study aimed to clarify the influence of tibial slope changes on the flexion gap in cruciate-retaining (CR) or posterior-stabilizing (PS) TKA. The flexion gap was measured using a tensor device with the femoral trial component in 20 cases each of CR- and PS-TKA. A wedge plate with a 5° inclination was placed on the tibial cut surface by switching its front-back direction to increase or decrease the tibial slope by 5°. The flexion gap after changing the tibial slope was compared to that of the neutral slope measured with a flat plate that had the same thickness as that of the wedge plate center. When the tibial slope decreased or increased by 5°, the flexion gap decreased or increased by 1.9 ± 0.6mm or 1.8 ± 0.4mm, respectively, with CR-TKA and 1.2 ± 0.4mm or 1.1 ± 0.3mm, respectively, with PS-TKA. The influence of changing the tibial slope by 5° on the flexion gap was approximately 2mm with CR-TKA and 1mm with PS-TKA. This information is useful when considering the effect of manipulating the tibial slope on the flexion gap when performing CR- or PS-TKA. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. The Lateral Meniscus as a Guide to Anatomical Tibial Tunnel Placement During Anterior Cruciate Ligament Reconstruction.

    PubMed

    Kassam, A M; Tillotson, L; Schranz, P J; Mandalia, V I

    2015-01-01

    The aim of the study is to show, on an MRI scan, that the posterior border of the anterior horn of the lateral meniscus (AHLM) could guide tibial tunnel position in the sagittal plane and provide anatomical graft position. One hundred MRI scans were analysed with normal cruciate ligaments and no evidence of meniscal injury. We measured the distance between the posterior border of the AHLM and the midpoint of the ACL by superimposing sagittal images. The mean distance between the posterior border of the AHLM and the ACL midpoint was -0.1mm (i.e. 0.1mm posterior to the ACL midpoint). The range was 5mm to -4.6mm. The median value was 0.0mm. 95% confidence interval was from -0.5 to 0.3mm. A normal, parametric distribution was observed and Intra- and inter-observer variability showed significant correlation (p<0.05) using Pearsons Correlation test (intra-observer) and Interclass correlation (inter-observer). Using the posterior border of the AHLM is a reproducible and anatomical marker for the midpoint of the ACL footprint in the majority of cases. It can be used intra-operatively as a guide for tibial tunnel insertion and graft placement allowing anatomical reconstruction. There will inevitably be some anatomical variation. Pre-operative MRI assessment of the relationship between AHLM and ACL footprint is advised to improve surgical planning. Level 4.

  3. Pseudoaneurysm of the Anterior Tibial Artery following Ankle Arthroscopy in a Soccer Player.

    PubMed

    Tonogai, Ichiro; Matsuura, Tetsuya; Iwame, Toshiyuki; Wada, Keizo; Takasago, Tomoya; Goto, Tomohiro; Hamada, Daisuke; Kawatani, Yohei; Fujimoto, Eiki; Kitagawa, Tetsuya; Takao, Shyoichiro; Iwamoto, Seiji; Yamanaka, Moriaki; Harada, Masafumi; Sairyo, Koichi

    2017-01-01

    Ankle arthroscopy carries a lower risk of vascular complications when standard anterolateral and anteromedial portals are used. However, the thickness of the fat pad at the anterior ankle affords little protection for the thin-walled anterior tibial artery, rendering it susceptible to indirect damage during procedures performed on the anterior ankle joint. To our knowledge, only 11 cases of pseudoaneurysm involving the anterior tibial artery after ankle arthroscopy have been described in the literature. Here we reported a rare case of a 19-year-old soccer player who presented with pseudoaneurysm of the anterior tibial artery following ankle arthroscopy using an ankle distraction method and underwent anastomosis for the anterior tibial artery injury. Excessive distraction of the ankle puts the neurovascular structures at greater risk for iatrogenic injury of the anterior tibial artery during ankle arthroscopy. Surgeons should look carefully for postoperative ankle swelling and pain after ankle arthroscopy.

  4. Pseudoaneurysm of the Anterior Tibial Artery following Ankle Arthroscopy in a Soccer Player

    PubMed Central

    Iwame, Toshiyuki; Hamada, Daisuke; Fujimoto, Eiki; Kitagawa, Tetsuya; Takao, Shyoichiro; Iwamoto, Seiji; Yamanaka, Moriaki; Harada, Masafumi

    2017-01-01

    Ankle arthroscopy carries a lower risk of vascular complications when standard anterolateral and anteromedial portals are used. However, the thickness of the fat pad at the anterior ankle affords little protection for the thin-walled anterior tibial artery, rendering it susceptible to indirect damage during procedures performed on the anterior ankle joint. To our knowledge, only 11 cases of pseudoaneurysm involving the anterior tibial artery after ankle arthroscopy have been described in the literature. Here we reported a rare case of a 19-year-old soccer player who presented with pseudoaneurysm of the anterior tibial artery following ankle arthroscopy using an ankle distraction method and underwent anastomosis for the anterior tibial artery injury. Excessive distraction of the ankle puts the neurovascular structures at greater risk for iatrogenic injury of the anterior tibial artery during ankle arthroscopy. Surgeons should look carefully for postoperative ankle swelling and pain after ankle arthroscopy. PMID:28607785

  5. A 3D finite element model to investigate prosthetic interface stresses of different posterior tibial slope.

    PubMed

    Shen, Yi; Li, Xiaomiao; Fu, Xiaodong; Wang, Weili

    2015-11-01

    Posterior tibial slope that is created during proximal tibial resection in total knee arthroplasty has emerged as an important factor in the mechanics of the knee joint and the surgical outcome. But the ideal degree of posterior tibial slope for recovery of the knee joint function and preventions of complications remains controversial and should vary in different racial groups. The objective of this paper is to investigate the effects of posterior tibial slope on contact stresses in the tibial polyethylene component of total knee prostheses. Three-dimensional finite element analysis was used to calculate contact stresses in tibial polyethylene component of total knee prostheses subjected to a compressive load. The 3D finite element model of total knee prosthesis was constructed from the images produced by 3D scanning technology. Stresses in tibial polyethylene component were calculated with four different posterior tibial slopes (0°, 3°, 6° and 9°). The 3D finite element model of total knee prosthesis we presented was well validated. We found that the stress distribution in the polythene as evaluated by the distributions of the von Mises stress, the maximum principle stress, the minimum principle stress and the Cpress were more uniform with 3° and 6° posterior tibial slopes than with 0° and 9° posterior tibial slopes. Moreover, the peaks of the above stresses and trends of changes with increasing degree of knee flexion were more ideal with 3° and 6° posterior slopes. The results suggested that the tibial component inclination might be favourable to 7°-10° so far as the stress distribution is concerned. The range of the tibial component inclination also can decrease the wear of polyethylene. Chinese posterior tibial slope is bigger than in the West, and the current domestic use of prostheses is imported from the West, so their demands to tilt back bone cutting can lead to shorten the service life of prostheses; this experiment result is of important

  6. The Tibial Slope in Patients With Achondroplasia: Its Characterization and Possible Role in Genu Recurvatum Development.

    PubMed

    Brooks, Jaysson T; Bernholt, David L; Tran, Kevin V; Ain, Michael C

    2016-06-01

    Genu recurvatum, a posterior resting position of the knee, is a common lower extremity deformity in patients with achondroplasia and has been thought to be secondary to ligamentous laxity. To the best of our knowledge, the role of the tibial slope has not been investigated, and no studies describe the tibial slope in patients with achondroplasia. Our goals were to characterize the tibial slope in children and adults with achondroplasia, explore its possible role in the development of genu recurvatum, and compare the tibial slope in patients with achondroplasia to that in the general population. We reviewed 252 lateral knee radiographs of 130 patients with achondroplasia seen at our clinic from November 2007 through September 2013. Patients were excluded if they had previous lower extremity surgery or radiographs with extreme rotation. We analyzed patient demographics and, on all radiographs, the tibial slope. We then compared the mean tibial slope to norms in the literature. Tibial slopes >90 degrees had an anterior tibial slope and received a positive prefix. Statistical analysis included intraclass and interclass reliability, Pearson correlation coefficient, and the Student t tests (significance, P<0.05). The overall mean tibial slope for the 252 knees was +1.32±7 degrees, which was significantly more anterior than the normal slopes reported in the literature for adults (7.2 to 10.7 degrees, P=0.0001) and children (10 to 11 degrees, P=0.0001). The Pearson correlation coefficient for mean tibial slope and age showed negative correlations of -0.4011 and -0.4335 for left and right knees, respectively. This anterior tibial slope produces proximal and posterior vector force components, which may shift the knee posteriorly in weightbearing. The mean tibial slope is significantly more anterior in patients with achondroplasia than in the general population; however, this difference diminishes as patients' age. An anterior tibial slope may predispose to a more posterior

  7. Effects of diabetic peripheral neuropathy on gait in vascular trans-tibial amputees.

    PubMed

    Nakajima, Hiroshi; Yamamoto, Sumiko; Katsuhira, Junji

    2018-07-01

    Patients with diabetes often develop diabetic peripheral neuropathy, which is a distal symmetric polyneuropathy, so foot function on the non-amputated side is expected to affect gait in vascular trans-tibial amputees. However, there is little information on the kinematics and kinetics of gait or the effects of diabetic peripheral neuropathy in vascular trans-tibial amputees. This study aimed to clarify these effects, including the biomechanics of the ankle on the non-amputated side. Participants were 10 vascular trans-tibial amputees with diabetic peripheral neuropathy (group V) and 8 traumatic trans-tibial amputees (group T). Each subject's gait was analyzed at a self-selected speed using a three-dimensional motion analyzer and force plates. Ankle plantarflexion angle, heel elevation angle, and peak and impulse of anterior ground reaction force were smaller on the non-amputated side during pre-swing in group V than in group T. Center of gravity during pre-swing on the non-amputated side was lower in group V than in group T. Hip extension torque during loading response on the prosthetic side was greater in group V than in group T. These findings suggest that the biomechanical function of the ankle on the non-amputated side during pre-swing is poorer in vascular trans-tibial amputees with DPN than in traumatic trans-tibial amputees; the height of the center of gravity could not be maintained during this phase in vascular trans-tibial amputees with diabetic peripheral neuropathy. The hip joint on the prosthetic side compensated for this diminished function at the ankle during loading response. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Avulsion of the tibial tuberosity in a litter of greyhound puppies.

    PubMed

    Skelly, C M; McAllister, H; Donnelly, W J

    1997-10-01

    Avulsion of the tibial tuberosity was diagnosed in six of seven greyhound littermates aged five and a half months. The puppies showed hindlimb lameness of varying severity. Radiological assessment of affected stifle joints revealed partial or complete avulsion of the tibial tuberosities. In four puppies the lesions were bilateral. Euthanasia of the two most severely affected puppies was performed; the changes observed on histopathological examination of their cranioproximal tibiae suggested that the underlying lesion was that of osteochondrosis. A hereditary predisposition in greyhounds to osteochondrosis of the physis between the apophysis and the cranioproximal tibial diaphysis is postulated.

  9. Automated Measurement of Patient-Specific Tibial Slopes from MRI

    PubMed Central

    Amerinatanzi, Amirhesam; Summers, Rodney K.; Ahmadi, Kaveh; Goel, Vijay K.; Hewett, Timothy E.; Nyman, Edward

    2017-01-01

    Background: Multi-planar proximal tibial slopes may be associated with increased likelihood of osteoarthritis and anterior cruciate ligament injury, due in part to their role in checking the anterior-posterior stability of the knee. Established methods suffer repeatability limitations and lack computational efficiency for intuitive clinical adoption. The aims of this study were to develop a novel automated approach and to compare the repeatability and computational efficiency of the approach against previously established methods. Methods: Tibial slope geometries were obtained via MRI and measured using an automated Matlab-based approach. Data were compared for repeatability and evaluated for computational efficiency. Results: Mean lateral tibial slope (LTS) for females (7.2°) was greater than for males (1.66°). Mean LTS in the lateral concavity zone was greater for females (7.8° for females, 4.2° for males). Mean medial tibial slope (MTS) for females was greater (9.3° vs. 4.6°). Along the medial concavity zone, female subjects demonstrated greater MTS. Conclusion: The automated method was more repeatable and computationally efficient than previously identified methods and may aid in the clinical assessment of knee injury risk, inform surgical planning, and implant design efforts. PMID:28952547

  10. Comparison of tibial shaft ski fractures in children and adults.

    PubMed

    Hamada, Tomo; Matsumoto, Kazu; Ishimaru, Daichi; Sumi, Hiroshi; Shimizu, Katsuji

    2014-09-01

    To examine whether child and adult skiers have different risk factors or mechanisms of injury for tibial shaft fractures. Descriptive epidemiological study. Prospectively analyzed the epidemiologic factors, injury types, and injury mechanisms at Sumi Memorial Hospital. This study analyzed information obtained from 276 patients with tibial fractures sustained during skiing between 2004 and 2012. We focused on 174 ski-related tibial shaft fractures with respect to the following factors: age, gender, laterality of fracture, skill level, mechanism of fracture (fall vs collision), scene of injury (steepness of slope), snow condition, and weather. Fracture pattern was graded according to Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification and mechanical direction [external (ER) or internal rotation (IR)]. Tibial shaft fractures were the most common in both children (89.3%) and adults (47.4%). There were no significant differences in gender, side of fracture, mechanism of fracture, snow condition, or weather between children and adults. Skill levels were significantly lower in children than in adults (P < 0.0001). Type A fractures were more dominant in children (73 cases, 72.3%) than in adults (39 cases, 53.4%). There was significantly more ER in children than in adults (P < 0.0001). Among children, female patients had significantly more IR than ER; in contrast, among adults, women were injured by ER. We found significant differences in some of these parameters, suggesting that child and adult skiers have different risk factors or mechanisms of injury for tibial shaft fractures.

  11. Radiation-induced graft polymerization for the preparation of a highly efficient UHMWPE fibrous adsorbent for Cr(VI) removal

    NASA Astrophysics Data System (ADS)

    Gao, Qianhong; Hua, Jiangtao; Li, Rong; Xing, Zhe; Pang, Lijuan; Zhang, Mingxing; Xu, Lu; Wu, Guozhong

    2017-01-01

    A novel fibrous adsorbent containing amine and quaternary ammonium groups was prepared by radiation-induced graft of glycidyl methacrylate (GMA) onto ultra-high molecular weight polyethylene (UHMWPE) fiber and further modifying with triethylenetetramine (TETA) and glycidyl trimethylammonium chloride (GTA). The ATR-IR spectra and SEM observation demonstrated that amine and quaternary ammonium groups were immobilized onto the surface of UHMWPE fiber. The principal factors affecting the adsorption of Cr(VI) ions have been investigated including pH of the aqueous solution, contact time, temperature and coexisting anions. This novel fibrous adsorbent could effectively adsorb Cr(VI) in the range of pH 1-9, and the maximum adsorption capacity reached 295 mg/g at pH 3 and 25 °C based on the Langmuir isotherm. It was found that adsorption equilibrium could be achieved within 2 h for initial Cr(VI) of 100 mg/L, following the pseudo-second order model. The effect of coexisting anions (including SO42-, H2PO4-, NO3-and Cl-) on the uptake of Cr(VI) was investigated in detail. Additionally, the adsorption saturated fiber could be regenerated by soaking in 0.5 mol/L NaOH solution, and the adsorption performance of this adsorbent could be maintained at 90% after eight cycles of adsorption-desorption. ATR-IR and XPS analysis revealed that Cr(VI) ions were adsorbed on the fiber adsorbent through ion exchange mechanism.

  12. Long-term complications following tibial plateau levelling osteotomy in small dogs with tibial plateau angles > 30°.

    PubMed

    Knight, Rebekah; Danielski, Alan

    2018-04-21

    Tibial plateau levelling osteotomy (TPLO) is commonly performed for surgical management of cranial cruciate ligament (CCL) disease. It has been suggested that small dogs may have steeper tibial plateau angles (TPAs) than large dogs, which has been associated with increased complication rates after TPLO. A retrospective study was performed to assess the rate and nature of long-term complications following TPLO in small dogs with TPAs>30°. Medical records were reviewed for dogs with TPAs>30° treated for CCL rupture by TPLO with a 2.0 mm plate over a five-year period. Radiographs were assessed to determine TPA, postoperative tibial tuberosity width and to identify any complication. Up-to-date medical records were obtained from the referring veterinary surgeon and any complications in the year after surgery were recorded. The effects of different variables on complication rate were assessed using logistic regression analysis. Minor complications were reported in 22.7 per cent of cases. This is similar to or lower than previously reported complication rates for osteotomy techniques in small dogs and dogs with steep TPAs. A smaller postoperative TPA was the only variable significantly associated with an increased complication rate. No major complications were identified. © British Veterinary Association (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  13. Mechanisms of plastic deformation in highly cross-linked UHMWPE for total hip components--the molecular physics viewpoint.

    PubMed

    Takahashi, Yasuhito; Shishido, Takaaki; Yamamoto, Kengo; Masaoka, Toshinori; Kubo, Kosuke; Tateiwa, Toshiyuki; Pezzotti, Giuseppe

    2015-02-01

    Plastic deformation is an unavoidable event in biomedical polymeric implants for load-bearing application during long-term in-vivo service life, which involves a mass transfer process, irreversible chain motion, and molecular reorganization. Deformation-induced microstructural alterations greatly affect mechanical properties and durability of implant devices. The present research focused on evaluating, from a molecular physics viewpoint, the impact of externally applied strain (or stress) in ultra-high molecular weight polyethylene (UHMWPE) prostheses, subjected to radiation cross-linking and subsequent remelting for application in total hip arthroplasty (THA). Two different types of commercial acetabular liners, which belong to the first-generation highly cross-linked UHMWPE (HXLPE), were investigated by means of confocal/polarized Raman microprobe spectroscopy. The amount of crystalline region and the spatial distribution of molecular chain orientation were quantitatively analyzed according to a combined theory including Raman selection rules for the polyethylene orthorhombic structure and the orientation distribution function (ODF) statistical approach. The structurally important finding was that pronounced recrystallization and molecular reorientation increasingly appeared in the near-surface regions of HXLPE liners with increasing the amount of plastic (compressive) deformation stored in the microstructure. Such molecular rearrangements, occurred in response to external strains, locally increase surface cross-shear (CS) stresses, which in turn trigger microscopic wear processes in HXLPE acetabular liners. Thus, on the basis of the results obtained at the molecular scale, we emphasize here the importance of minimizing the development of irrecoverable deformation strain in order to retain the pristine and intrinsically high wear performance of HXLPE components. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. The role of fibers in the femoral attachment of the anterior cruciate ligament in resisting tibial displacement.

    PubMed

    Kawaguchi, Yasuyuki; Kondo, Eiji; Takeda, Ryo; Akita, Keiichi; Yasuda, Kazunori; Amis, Andrew A

    2015-03-01

    The purpose was to clarify the load-bearing functions of the fibers of the femoral anterior cruciate ligament (ACL) attachment in resisting tibial anterior drawer and rotation. A sequential cutting study was performed on 8 fresh-frozen human knees. The femoral attachment of the ACL was divided into a central area that had dense fibers inserting directly into the femur and anterior and posterior fan-like extension areas. The ACL fibers were cut sequentially from the bone: the posterior fan-like area in 2 stages, the central dense area in 4 stages, and then the anterior fan-like area in 2 stages. Each knee was mounted in a robotic joint testing system that applied tibial anteroposterior 6-mm translations and 10° or 15° of internal rotation at 0° to 90° of flexion. The reduction of restraining force or moment was measured after each cut. The central area resisted 82% to 90% of the anterior drawer force; the anterior fan-like area, 2% to 3%; and the posterior fan-like area, 11% to 15%. Among the 4 central areas, most load was carried close to the roof of the intercondylar notch: the anteromedial bundle resisted 66% to 84% of the force and the posterolateral bundle resisted 16% to 9% from 0° to 90° of flexion. There was no clear pattern for tibial internal rotation, with the load shared among the posterodistal and central areas near extension and mostly the central areas in flexion. Under the experimental conditions described, 66% to 84% of the resistance to tibial anterior drawer arose from the ACL fibers at the central-proximal area of the femoral attachment, corresponding to the anteromedial bundle; the fan-like extension fibers contributed very little. This work did not support moving a single-bundle ACL graft to the side wall of the notch or attempting to cover the whole attachment area if the intention was to mimic how the natural ACL resists tibial displacements. There is ongoing debate about how best to reconstruct the ACL to restore normal knee function

  15. The Role of Fibers in the Femoral Attachment of the Anterior Cruciate Ligament in Resisting Tibial Displacement

    PubMed Central

    Kawaguchi, Yasuyuki; Kondo, Eiji; Takeda, Ryo; Akita, Keiichi; Yasuda, Kazunori; Amis, Andrew A.

    2015-01-01

    Purpose The purpose was to clarify the load-bearing functions of the fibers of the femoral anterior cruciate ligament (ACL) attachment in resisting tibial anterior drawer and rotation. Methods A sequential cutting study was performed on 8 fresh-frozen human knees. The femoral attachment of the ACL was divided into a central area that had dense fibers inserting directly into the femur and anterior and posterior fan-like extension areas. The ACL fibers were cut sequentially from the bone: the posterior fan-like area in 2 stages, the central dense area in 4 stages, and then the anterior fan-like area in 2 stages. Each knee was mounted in a robotic joint testing system that applied tibial anteroposterior 6-mm translations and 10° or 15° of internal rotation at 0° to 90° of flexion. The reduction of restraining force or moment was measured after each cut. Results The central area resisted 82% to 90% of the anterior drawer force; the anterior fan-like area, 2% to 3%; and the posterior fan-like area, 11% to 15%. Among the 4 central areas, most load was carried close to the roof of the intercondylar notch: the anteromedial bundle resisted 66% to 84% of the force and the posterolateral bundle resisted 16% to 9% from 0° to 90° of flexion. There was no clear pattern for tibial internal rotation, with the load shared among the posterodistal and central areas near extension and mostly the central areas in flexion. Conclusions Under the experimental conditions described, 66% to 84% of the resistance to tibial anterior drawer arose from the ACL fibers at the central-proximal area of the femoral attachment, corresponding to the anteromedial bundle; the fan-like extension fibers contributed very little. This work did not support moving a single-bundle ACL graft to the side wall of the notch or attempting to cover the whole attachment area if the intention was to mimic how the natural ACL resists tibial displacements. Clinical Relevance There is ongoing debate about how best

  16. What Components Comprise the Measurement of the Tibial Tuberosity-Trochlear Groove Distance in a Patellar Dislocation Population?

    PubMed

    Tensho, Keiji; Akaoka, Yusuke; Shimodaira, Hiroki; Takanashi, Seiji; Ikegami, Shota; Kato, Hiroyuki; Saito, Naoto

    2015-09-02

    The tibial tuberosity-trochlear groove distance is used as an indicator for medial tibial tubercle transfer; however, to our knowledge, no studies have verified whether this distance is strongly affected by tubercle lateralization at the proximal part of the tibia. We hypothesized that the tibial tuberosity-trochlear groove distance is mainly affected by tibial tubercle lateralization at the proximal part of the tibia. Forty-four patients with a history of patellar dislocation and forty-four age and sex-matched controls were analyzed with use of computed tomography. The tibial tuberosity-trochlear groove distance, tibial tubercle lateralization, trochlear groove medialization, and knee rotation were measured and were compared between the patellar dislocation group and the control group. The association between the tibial tuberosity-trochlear groove distance and three other parameters was calculated with use of the Pearson correlation coefficient and partial correlation analysis. There were significant differences in the tibial tuberosity-trochlear groove distance (p < 0.001) and knee rotation (p < 0.001), but there was no difference in the tibial tubercle lateralization (p = 0.13) and trochlear groove medialization (p = 0.08) between the patellar dislocation group and the control group. The tibial tuberosity-trochlear groove distance had no linear correlation with tubercle lateralization (r = 0.21) or groove medialization (r = -0.15); however, knee rotation had a good positive correlation in the patellar dislocation group (r = 0.62). After adjusting for the remaining parameters, knee rotation strongly correlated with the tibial tuberosity-trochlear groove distance (r = 0.69, p < 0.001), whereas tubercle lateralization showed moderate significant correlations in the patellar dislocation group (r = 0.42; p = 0.005). Because the tibial tuberosity-trochlear groove distance is affected more by knee rotation than by tubercle malposition, its use as an indicator for

  17. Micro-Raman spectroscopy for the crystallinity characterization of UHMWPE hip cups run on joint simulators

    NASA Astrophysics Data System (ADS)

    Bertoluzza, A.; Fagnano, C.; Rossi, M.; Tinti, A.; Cacciari, G. L.

    2000-03-01

    In this work Raman microspectrometry was used to evaluate the crystallinity changes of hip cups made of ultra-high molecular weight polyethylene (UHMWPE). In vitro experiments were carried out using hip joint movement-wear simulators, run for five million cycles in water or bovine calf serum. The hip cups were subjected to mechanical friction with ceramic femoral heads (alumina-zirconia blend). The crystallinity of the polymer hip cups was studied as a function of inner surface position and thickness, from the stressed surface to the unstressed outer one. The Partial Least Square (PLS-l) calibration was used to correlate the Raman spectra with the crystallinity of the polymer measured with DSC calorimetry.

  18. Standing balance in people with trans-tibial amputation due to vascular causes: A literature review.

    PubMed

    Seth, Mayank; Lamberg, Eric

    2017-08-01

    Balance is an important variable to consider during the rehabilitation process of individuals with trans-tibial amputation. Limited evidence exists on the balance abilities of people with trans-tibial amputation due to vascular causes. The purpose of this article is to review literature and determine if standing balance is diminished in people with trans-tibial amputation due to vascular causes. Literature review. Data were obtained from PubMed, Google Scholar, OandP.org , CINHAL, and Science Direct. Studies were selected only if they included standing balance assessment of people with unilateral trans-tibial amputation due to vascular causes. The review yielded seven articles that met the inclusion criteria. The general test methodology required participants to stand still on force platforms, with feet together, while center of pressure or postural sway was recorded. According to the findings of this review, individuals with trans-tibial amputees due to vascular causes have diminished balance abilities. Limited evidence suggests their balance might be further diminished as compared to individuals with trans-tibial amputation due to trauma. Although the evidence is limited, because of the underlying pathology and presence of comorbidities in individuals with trans-tibial amputation due to vascular causes, one cannot ignore these findings, as even a minor injury from a fall may develop into a non-healing ulcer and affect their health and well-being more severely than individuals with trans-tibial amputation due to trauma. Clinical relevance Individuals with trans-tibial amputation due to vascular causes have diminished balance abilities compared to healthy individuals and individuals with trans-tibial amputation due to trauma. This difference should be considered when designing and fabricating prostheses. Prosthetists and rehabilitation clinicians should consider designing amputation cause-specific rehabilitation interventions, focussing on balance and other

  19. Segmental transports for posttraumatic lower extremity bone defects: are femoral bone transports safer than tibial?

    PubMed

    Liodakis, Emmanouil; Kenawey, Mohamed; Krettek, Christian; Ettinger, Max; Jagodzinski, Michael; Hankemeier, Stefan

    2011-02-01

    The long-term outcomes following femoral and tibial segment transports are not well documented. Purpose of the study is to compare the complication rates and life quality scores of femoral and tibial transports in order to find what are the complication rates of femoral and tibial monorail bone transports and if they are different? We retrospectively analyzed the medical records of 8 femoral and 14 tibial consecutive segment transports performed with the monorail technique between 2001 and 2008 in our institution. Mean follow-up was 5.1 ± 2.1 years with a minimum follow-up of 2 years. Aetiology of the defects was posttraumatic in all cases. Four femoral (50%) and nine tibial (64%) fractures were open. The Short Form-36 (SF-36) health survey was used to compare the life quality after femoral and tibial bone transports. The Mann-Whiney U test, Fisher exact test, and the Student's two tailed t-test were used for statistical analysis. P ≤ 0.05 was considered to be statistically significant. The tibial transport was associated with higher rates of severe complications and additional procedures (1.5 ± 0.9 vs. 3.4 ± 2.7, p = 0.048). Three patients of the tibial group were amputated because of recurrent infections and one developed a complete regenerate insufficiency that was treated with partial diaphyseal tibial replacement. Contrary to that none of patients of the femoral group developed a complete regenerate insufficiency or was amputated. Tibial bone transports have a higher rate of complete and incomplete regenerate insufficiency and can more often end in an amputation. The authors suggest systematic weekly controls of the CRP value and of the callus formation in patients with posttraumatic tibia bone transports. Further comparative studies comparing the results of bone transports with and without intramedullary implants are necessary.

  20. [Intra-articular reinforcement of a partially torn anterior cruciate ligament (ACL) using newly developed UHMWPE biomaterial in combination with Hexalon ACL/PCL screws: ex-vivo mechanical testing of an animal knee model].

    PubMed

    Fedorová, P; Srnec, R; Pěnčík, J; Dvořák, M; Krbec, M; Nečas, A

    2015-01-01

    PURPOSE OF THE STUDY Recent trends in the experimental surgical management of a partial anterior cruciate ligament (ACL) rupture in animals show repair of an ACL lesion using novel biomaterials both for biomechanical reinforcement of a partially unstable knee and as suitable scaffolds for bone marrow stem cell therapy in a partial ACL tear. The study deals with mechanical testing of the newly developed ultra-high-molecular-weight polyethylene (UHMWPE) biomaterial anchored to bone with Hexalon biodegradable ACL/PCL screws, as a new possibility of intra-articular reinforcement of a partial ACL tear. MATERIAL AND METHODS Two groups of ex vivo pig knee models were prepared and tested as follows: the model of an ACL tear stabilised with UHMWPE biomaterial using a Hexalon ACL/PCL screw (group 1; n = 10) and the model of an ACL tear stabilised with the traditional, and in veterinary medicine used, extracapsular technique involving a monofilament nylon fibre, a clamp and a Securos bone anchor (group 2; n = 11). The models were loaded at a standing angle of 100° and the maximum load (N) and shift (mm) values were recorded. RESULTS In group 1 the average maximal peak force was 167.6 ± 21.7 N and the shift was on average 19.0 ± 4.0 mm. In all 10 specimens, the maximum load made the UHMWPE implant break close to its fixation to the femur but the construct/fixation never failed at the site where the material was anchored to the bone. In group 2, the average maximal peak force was 207.3 ± 49.2 N and the shift was on average 24.1 ± 9.5 mm. The Securos stabilisation failed by pullout of the anchor from the femoral bone in nine out of 11 cases; the monofilament fibre ruptured in two cases. CONCLUSIONS It can be concluded that a UHMWPE substitute used in ex-vivo pig knee models has mechanical properties comparable with clinically used extracapsular Securos stabilisation and, because of its potential to carry stem cells and bioactive substances, it can meet the requirements for

  1. Physeal growth arrest after tibial lengthening in achondroplasia: 23 children followed to skeletal maturity.

    PubMed

    Song, Sang-Heon; Agashe, Mandar Vikas; Huh, Young-Jae; Hwang, Soon-Young; Song, Hae-Ryong

    2012-06-01

    Bilateral tibial lengthening has become one of the standard treatments for upper segment-lower segment disproportion and to improve quality of life in achondroplasia. We determined the effect of tibial lengthening on the tibial physis and compared tibial growth that occurred at the physis with that in non-operated patients with achondroplasia. We performed a retrospective analysis of serial radiographs until skeletal maturity in 23 achondroplasia patients who underwent bilateral tibial lengthening before skeletal maturity (lengthening group L) and 12 achondroplasia patients of similar height and age who did not undergo tibial lengthening (control group C). The mean amount of lengthening of tibia in group L was 9.2 cm (lengthening percentage: 60%) and the mean age at the time of lengthening was 8.2 years. The mean duration of follow-up was 9.8 years. Skeletal maturity (fusion of physis) occurred at 15.2 years in group L and at 16.0 years in group C. The actual length of tibia (without distraction) at skeletal maturity was 238 mm in group L and 277 mm in group C (p = 0.03). The mean growth rates showed a decrease in group L relative to group C from about 2 years after surgery. Physeal closure was most pronounced on the anterolateral proximal tibial physis, with relative preservation of the distal physis. Our findings indicate that physeal growth rate can be disturbed after tibial lengthening in achondroplasia, and a close watch should be kept for such an occurrence-especially when lengthening of more than 50% is attempted.

  2. Quantitative In Situ Analysis of the Anterior Cruciate Ligament: Length, Midsubstance Cross-sectional Area, and Insertion Site Areas.

    PubMed

    Fujimaki, Yoshimasa; Thorhauer, Eric; Sasaki, Yusuke; Smolinski, Patrick; Tashman, Scott; Fu, Freddie H

    2016-01-01

    Quantification of the cross-sectional area (CSA) of the anterior cruciate ligament (ACL) in different loading conditions is important for understanding the native anatomy and thus achieving anatomic reconstruction. The ACL insertion sites are larger than the ACL midsubstance, and the isthmus (region of the smallest CSA) location may vary with the load or flexion angle. To (1) quantify the CSA along the entire ACL, (2) describe the location of the ACL isthmus, (3) explore the relationship between ACL length and CSA, and (4) validate magnetic resonance imaging (MRI) for assessing the CSA of the midsubstance ACL. Descriptive laboratory study. Eight cadaveric knees were dissected to expose the ACL and its attachments. Knees were positioned using a robotic loading system through a range of flexion angles in 3 loading states: (1) unloaded, (2) anterior tibial translation, and (3) combined rotational load of valgus and internal torque. Laser scanning quantified the shape of the ACL and its insertion site boundaries. The CSA of the ACL was measured, and the location of the isthmus was determined; the CSA of the ACL was also estimated from MRI and compared with the laser-scanned data. The CSA of the ACL varied along the ligament, and the isthmus existed at an average (±SD) of 53.8% ± 5.5% of the distance from the tibial insertion center to the femoral insertion center. The average CSA at the isthmus was smallest in extension (39.9 ± 13.7 mm(2)) and increased with flexion (43.9 ± 12.1 mm(2) at 90°). The ACL length was shortest at 90° of flexion and increased by 18.8% ± 10.1% in unloaded extension. Application of an anterior load increased the ACL length by 5.0% ± 3.3% in extension, and application of a combined rotational load increased its length by 4.1% ± 3.0% in extension. The ACL isthmus is located almost half of the distance between the insertion sites. The CSA of the ACL at the isthmus is largest with the knee unloaded and at 90° of flexion, and the area

  3. High resolution ultrasonography of the tibial nerve in diabetic peripheral neuropathy.

    PubMed

    Singh, Kunwarpal; Gupta, Kamlesh; Kaur, Sukhdeep

    2017-12-01

    High-resolution ultrasonography of the tibial nerve is a fast and non invasive tool for diagnosis of diabetic peripheral neuropathy. Our study was aimed at finding out the correlation of the cross sectional area and maximum thickness of nerve fascicles of the tibial nerve with the presence and severity of diabetic peripheral neuropathy. 75 patients with type 2 diabetes mellitus clinically diagnosed with diabetic peripheral neuropathy were analysed, and the severity of neuropathy was determined using the Toronto Clinical Neuropathy Score. 58 diabetic patients with no clinical suspicion of diabetic peripheral neuropathy and 75 healthy non-diabetic subjects were taken as controls. The cross sectional area and maximum thickness of nerve fascicles of the tibial nerves were calculated 3 cm cranial to the medial malleolus in both lower limbs. The mean cross sectional area (22.63 +/- 2.66 mm 2 ) and maximum thickness of nerve fascicles (0.70 mm) of the tibial nerves in patients with diabetic peripheral neuropathy compared with both control groups was significantly larger, and statistically significant correlation was found with the Toronto Clinical Neuropathy Score ( p < 0.001). The diabetic patients with no signs of peripheral neuropathy had a larger mean cross sectional area (14.40 +/- 1.72 mm 2 ) and maximum thickness of nerve fascicles of the tibial nerve (0.40 mm) than healthy non-diabetic subjects (12.42 +/- 1.01 mm 2 and 0.30 mm respectively). The cross sectional area and maximum thickness of nerve fascicles of the tibial nerve is larger in diabetic patients with or without peripheral neuropathy than in healthy control subjects, and ultrasonography can be used as a good screening tool in these patients.

  4. Chronic shin splints. Classification and management of medial tibial stress syndrome.

    PubMed

    Detmer, D E

    1986-01-01

    A clinical classification and treatment programme has been developed for chronic medial tibial stress syndrome. Medial tibial stress syndrome has been reported to be either tibial stress fracture or microfracture, tibial periostitis, or distal deep posterior chronic compartment syndrome. Three chronic types exist and may coexist: Type I (tibial microfracture, bone stress reaction or cortical fracture); type II (periostalgia from chronic avulsion of the periosteum at the periosteal-fascial junction); and type III (chronic compartment syndrome syndrome). Type I disease is treated nonoperatively. Operations for resistant types II and III medial tibial stress syndrome were performed in 41 patients. Bilaterality was common (type II, 50% type III, 88%). Seven had coexistent type II/III; one had type I/II. Preoperative symptoms averaged 24 months in type II, 6 months in type III, and 33 months in types II/III. Mean age was 22 years (15 to 51). Resting compartment pressures were normal in type II (mean 12 mm Hg) and elevated in type III and type II/III (mean 23 mm Hg). Type II and type II/III patients received fasciotomy plus periosteal cauterisation. Type III patients had fasciotomy only. All procedures were performed on an outpatient basis using local anaesthesia. Follow up was complete and averaged 6 months (2 to 14 months). Improved performance was as follows: type II, 93%, type III, 100%; type II/III, 86%. Complete cures were as follows: type II, 78%; type III, 75%; and type II/III, 57%. This experience suggests that with precise diagnosis and treatment involving minimal risk and cost the athlete has a reasonable chance of return to full activity.

  5. Comparison of intraoperative anthropometric measurements of the proximal tibia and tibial component in total knee arthroplasty.

    PubMed

    Miyatake, Naohisa; Sugita, Takehiko; Aizawa, Toshimi; Sasaki, Akira; Maeda, Ikuo; Kamimura, Masayuki; Fujisawa, Hirokazu; Takahashi, Atsushi

    2016-09-01

    Precise matching of the tibial component and resected bony surfaces and proper rotational implanting of the tibial component are crucial for successful total knee arthroplasty. We aimed to analyze the exact anthropometric proximal tibial data of Japanese patients undergoing total knee arthroplasty and correlate the measurements with the dimensions of current total knee arthroplasty systems. A total of 703 knees in 566 Japanese patients who underwent total knee arthroplasty for osteoarthritis were included. The bone resection in the proximal tibia was performed perpendicular to the tibial axis in the frontal plane. Measurements of the proximal tibia were intraoperatively obtained after proximal tibial preparation. There were significant positive correlations between the lateral anteroposterior and medial anteroposterior and mediolateral dimensions. A progressive decrease in the mediolateral/lateral anteroposterior ratio with an increasing lateral anteroposterior dimension or the mediolateral/anteroposterior ratio with an increasing anteroposterior dimension was observed. The lateral anteroposterior dimension was smaller than the medial anteroposterior dimension by a mean of 4.8 ± 2.0 mm. The proximal tibia exhibited asymmetry between the lateral and medial plateaus. A comparison of the morphological data and dimensions of the implants, one of which was a symmetric tibial component (NexGen) and the others were asymmetric (Genesis II and Persona), indicated that an asymmetric tibial component could be beneficial to maximize tibial plateau coverage. This study provided important reference data for designing a proper tibial component for Japanese people. The proximal tibial cut surface was asymmetric. There was wide dispersion in the lateral anteroposterior, medial anteroposterior, and mediolateral dimensions depending on the patient. Our data showed that the tibial components of the Genesis II and Persona rather than that of the NexGen may be preferable for

  6. Pathomorphism of spiral tibial fractures in computed tomography imaging.

    PubMed

    Guzik, Grzegorz

    2011-01-01

    Spiral fractures of the tibia are virtually homogeneous with regard to their pathomorphism. The differences that are seen concern the level of fracture of the fibula, and, to a lesser extent, the level of fracture of the tibia, the length of fracture cleft, and limb shortening following the trauma. While conventional radiographs provide sufficient information about the pathomorphism of fractures, computed tomography can be useful in demonstrating the spatial arrangement of bone fragments and topography of soft tissues surrounding the fracture site. Multiple cross-sectional computed tomography views of spiral fractures of the tibia show the details of the alignment of bone chips at the fracture site, axis of the tibial fracture cleft, and topography of soft tissues that are not visible on standard radiographs. A model of a spiral tibial fracture reveals periosteal stretching with increasing spiral and longitudinal displacement. The cleft in tibial fractures has a spiral shape and its line is invariable. Every spiral fracture of both crural bones results in extensive damage to the periosteum and may damage bellies of the long flexor muscle of toes, flexor hallucis longus as well as the posterior tibial muscle. Computed tomography images of spiral fractures of the tibia show details of damage that are otherwise invisible on standard radiographs. Moreover, CT images provide useful information about the spatial location of the bone chips as well as possible threats to soft tissues that surround the fracture site. Every spiral fracture of the tibia is associated with disruption of the periosteum. 1. Computed tomography images of spiral fractures of the tibia show details of damage otherwise invisible on standard radiographs, 2. The sharp end of the distal tibial chip can damage the tibialis posterior muscle, long flexor muscles of the toes and the flexor hallucis longus, 3. Every spiral fracture of the tibia is associated with disruption of the periosteum.

  7. Sequential avulsions of the tibial tubercle in an adolescent basketball player.

    PubMed

    Huang, Ying Chieh; Chao, Ying-Hao; Lien, Fang-Chieh

    2010-05-01

    Tibial tubercle avulsion is an uncommon fracture in physically active adolescents. Sequential avulsion of tibial tubercles is extremely rare. We reported a healthy, active 15-year-old boy who suffered from left tibial tubercle avulsion fracture during a basketball game. He received open reduction and internal fixation with two smooth Kirschner wires and a cannulated screw, with every effort to reduce the plate injury. Long-leg splint was used for protection followed by programmed rehabilitation. He recovered uneventfully and returned to his previous level of activity soon. Another avulsion fracture happened at the right tibial tubercle 3.5 months later when he was playing the basketball. From the encouragement of previous successful treatment, we provided him open reduction and fixation with two small-caliber screws. He recovered uneventfully and returned to his previous level of activity soon. No genu recurvatum or other deformity was happening in our case at the end of 2-year follow-up. No evidence of Osgood-Schlatter disease or osteogenesis imperfecta was found. Sequential avulsion fractures of tibial tubercles are rare. Good functional recovery can often be obtained like our case if we treat it well. To a physically active adolescent, we should never overstate the risk of sequential avulsion of the other leg to postpone the return to an active, functional life.

  8. Management of combined knee medial compartmental and patellofemoral osteoarthritis with lateral closing wedge osteotomy with anterior translation of the distal tibial fragment: Does the degree of anteriorization affect the functional outcome and posterior tibial slope?

    PubMed

    Sadek, Ahmed F; Osman, Mohammed K; Laklok, Mohamed A

    2016-10-01

    The aim of this study was to assess the effect of degree of anterior translation of the distal tibial fragment after lateral closing wedge high tibial osteotomy in patients having combined knee medial compartmental and patellofemoral osteoarthritis. A retrospective study was conducted on 64 patients who were operated on for combined knee medial compartmental and patellofemoral osteoarthritis, by lateral closing wedge high tibial osteotomy with anterior translation of the distal tibial fragment. They were divided into two groups; Group I comprising 32 patients (34 knees, mean age of 51.4±7years) whose degree of anterior translation was <1cm and Group II comprising 32 patients (33 knees, mean age of 52.2±8.3years) whose degree of anterior translation was >1.5cm. The final assessment was performed via: visual analog scale, postoperative Knee Society clinical rating system function score, active range of motion, time to union, degree of correction of mechanical axis, posterior tibial slope, and Insall-Salvati ratio. Group II patients exhibited statistically superior mean postoperative score and better return to their work than Group I (P=0.013, 0.076, respectively). Both groups showed statistically significant differences between the preoperative and postoperative evaluation parameters (P<0.001). The posterior tibial slope was decreased in both groups but with no significant difference (P=0.527). Lateral closing wedge high tibial osteotomy combined with anterior translation of the distal tibial fragment more than 1.5cm achieved significantly better postoperative functional knee score. Both groups exhibited comparatively decreased posterior tibial slope. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Does increased topside conformity in modular total knee arthroplasty lead to increased backside wear?

    PubMed

    Schwarzkopf, Ran; Scott, Richard D; Carlson, Evan M; Currier, John H

    2015-01-01

    Modular metal-backed tibia components allow surgeons intraoperative flexibility. Although it is known that modular tibia components introduce the possibility for backside wear resulting from relative motion between the polyethylene insert and the tibial baseplate, it is not known to what degree variability in the conformity of the tibial polyethylene liner itself might contribute to backside wear. The purpose of this study was to determine whether a flat, cruciate-retaining tibial polyethylene bearing generates less backside wear than a more conforming (curved) tibial polyethylene bearing in an analysis of specimens explanted during revision surgery. The study included 70 total knee inserts explanted at revision surgery, all implanted and explanted by the same surgeon. Two different cruciate-retaining insert options in an otherwise similar knee system were used: one with a curved-on-flat (17) articular geometry and one with a highly conforming curved-on-curved design (53); both groups were sequential cohorts. The composite backside wear depth for the insert as well as the volume of backside wear was measured and compared between groups. The median linear backside-normalized wear for the posterior lipped inserts was 0.0063 mm/year (range, 0-0.085 mm/year), which was lower than for the curved inserts at 0.05 mm/year (range, 0.00003-0.14 mm/year) (p<0.001). The median calculated volumetric backside-normalized wear for the posterior lipped inserts was 14.2 mm3/year (range, 0-282.8 mm3/year) compared with 117 mm3/year (range, 2.1-312 mm3/year) for the curved inserts (p<0.001). In this retrieval study, more conforming tibial inserts demonstrated more backside-normalized wear than the flatter designs. This suggests that in this modular total knee arthroplasty design, higher articular conformity to address the issues of high bearing contact stress comes at a price: increased torque transmitted to the backside insert-to-tray interface. We suggest further work be undertaken

  10. Medial tibial pain. A prospective study of its cause among military recruits.

    PubMed

    Milgrom, C; Giladi, M; Stein, M; Kashtan, H; Margulies, J; Chisin, R; Steinberg, R; Swissa, A; Aharonson, Z

    1986-12-01

    In a prospective study of 295 infantry recruits during 14 weeks of basic training, 41% had medial tibial pain. Routine scintigraphic evaluation in cases of medial tibial bone pain showed that 63% had abnormalities. A stress fracture was found in 46%. Only two patients had periostitis. None had ischemic medial compartment syndrome. Physical examination could not differentiate between cases with medial tibial bone pain secondary to stress fractures and those with scintigraphically normal tibias. When both pain and swelling were localized in the middle one-third of the tibia, the lesion most likely proved to be a stress fracture.

  11. Microstructural modifications induced by accelerated aging and lipid absorption in remelted and annealed UHMWPEs for total hip arthroplasty

    PubMed Central

    Puppulin, Leonardo; Zhu, Wenliang; Sugano, Nobuhiko

    2014-01-01

    Three types of commercially available ultra-high molecular weight polyethylene (UHMWPE) acetabular cups currently used in total hip arthroplasty have been studied by means of Raman micro-spectroscopy to unfold the microstructural modification induced by the oxidative degradation after accelerated aging with and without lipid absorption. The three investigated materials were produced by three different manufacturing procedures, as follows: irradiation followed by remelting, one-step irradiation followed by annealing, 3-step irradiation and annealing. Clear microstructural differences were observed in terms of phase contents (i.e. amorphous, crystalline and intermediate phase fraction). The three-step annealed material showed the highest crystallinity fraction in the bulk, while the remelted polyethylene is clearly characterized by the lowest content of crystalline phase and the highest content of amorphous phase. After accelerated aging either with or without lipids, the amount of amorphous phase decreased in all the samples as a consequence of the oxidation-induced recrystallization. The most remarkable variations of phase contents were detected in the remelted and in the single-step annealed materials. The presence of lipids triggered oxidative degradation especially in the remelted polyethylene. Such experimental evidence might be explained by the highest amount of amorphous phase in which lipids can be absorbed prior to accelerated aging. The results of these spectroscopic characterizations help to rationalize the complex effect of different irradiation and post-irradiation treatments on the UHMWPE microstructure and gives useful information on how significantly any single step of the manufacturing procedures might affect the oxidative degradation of the polymer. PMID:25179830

  12. Tibial and fibular nerves evaluation using intraoperative electromyography in rats.

    PubMed

    Nepomuceno, André Coelho; Politani, Elisa Landucci; Silva, Eduardo Guandelini da; Salomone, Raquel; Longo, Marco Vinicius Losso; Salles, Alessandra Grassi; Faria, José Carlos Marques de; Gemperli, Rolf

    2016-08-01

    To evaluate a new model of intraoperative electromyographic (EMG) assessment of the tibial and fibular nerves, and its respectives motor units in rats. Eight Wistar rats underwent intraoperative EMG on both hind limbs at two different moments: week 0 and week 12. Supramaximal electrical stimulation applied on sciatic nerve, and compound muscle action potential recorded on the gastrocnemius muscle (GM) and the extensor digitorum longus muscle (EDLM) through electrodes at specifics points. Motor function assessment was performaced through Walking Track Test. Exposing the muscles and nerves for examination did not alter tibial (p=0.918) or fibular (p=0.877) function between the evaluation moments. Electromyography of the GM, innervated by the tibial nerve, revealed similar amplitude (p=0.069) and latency (p=0.256) at week 0 and at 12 weeks, creating a standard of normality. Meanwhile, electromyography of the EDLM, innervated by the fibular nerve, showed significant differences between the amplitudes (p=0.003) and latencies (p=0.021) at the two different moments of observation. Intraoperative electromyography determined and quantified gastrocnemius muscle motor unit integrity, innervated by tibial nerve. Although this study was not useful to, objectively, assess extensor digitorum longus muscle motor unit, innervated by fibular nerve.

  13. Total knee arthroplasty after high tibial osteotomy. A comparison study in patients who had bilateral total knee replacement.

    PubMed

    Meding, J B; Keating, E M; Ritter, M A; Faris, P M

    2000-09-01

    The outcome of total knee replacement after high tibial osteotomy remains uncertain. We hypothesized that the results of total knee replacement with or without a previous high tibial osteotomy are similar. The results of a consecutive series of thirty-nine bilateral total knee arthroplasties performed with cement at an average of 8.7 years after unilateral high tibial osteotomy were reviewed. There were twenty-seven men and twelve women. Preoperatively, the knee scores according to the system of the Knee Society were similar for all of the knees; however, valgus alignment and patella infera were more common in the knees with a previous high tibial osteotomy. Bilateral total knee replacement was staged in seven patients and was simultaneous in thirty-two patients. The results of the total knee arthroplasties were retrospectively reviewed with respect to the knee and function scores according to the system of the Knee Society, the radiographic findings, and the complications. Intraoperatively, no notable differences were identified in the number of medial, lateral, or lateral patellar releases required. However, less lateral tibial bone was resected in the group with a previous high tibial osteotomy (average, 3.3 millimeters) than in the group without a high tibial osteotomy (average, 7.5 millimeters). The average duration of follow-up was 7.5 years (range, three to sixteen years) in the group with a previous high tibial osteotomy and 6.8 years (range, two to ten years) in the group without a high tibial osteotomy. At the time of the final follow-up, the knee and function scores were similar for the two groups (89.0 and 81.0 points, respectively, for the group with a previous high tibial osteotomy, and 89.6 and 83.9 points, respectively, for the group without a high tibial osteotomy). Although more knees were free of pain in the group without a previous high tibial osteotomy (thirty-six) than in the group with a previous osteotomy (thirty-three), this difference was

  14. Management of tibial fractures using a circular external fixator in two calves.

    PubMed

    Aithal, Hari Prasad; Kinjavdekar, Prakash; Amarpal; Pawde, Abhijit Motiram; Singh, Gaj Raj; Setia, Harish Chandra

    2010-07-01

    To report the repair of tibial diaphyseal fractures in 2 calves using a circular external skeletal fixator (CEF). Clinical report. Crossbred calves (n=2; age: 6 months; weight: 55 and 60 kg). Mid-diaphyseal tibial fractures were repaired by the use of a 4-ring CEF (made of aluminum rings with 2 mm K-wires) alone in 1 calf and in combination with hemicerclage wiring in 1 calf. Both calves had good weight bearing with moderate lameness postoperatively. Fracture healing occurred by day 60 in 1 calf and by day 30 in calf 2. The CEF was well maintained and tolerated by both calves through fracture healing. Joint mobility and limb usage improved gradually after CEF removal. CEF provided a stable fixation of tibial fractures and healing within 60 days and functional recovery within 90 days. CEF can be safely and successfully used for the management of selected tibial fractures in calves.

  15. Treatment of segmental tibial fractures with supercutaneous plating.

    PubMed

    He, Xianfeng; Zhang, Jingwei; Li, Ming; Yu, Yihui; Zhu, Limei

    2014-08-01

    Segmental tibial fractures usually follow a high-energy trauma and are often associated with many complications. The purpose of this report is to describe the authors' results in the treatment of segmental tibial fractures with supercutaneous locking plates used as external fixators. Between January 2009 and March 2012, a total of 20 patients underwent external plating (supercutaneous plating) of the segmental tibial fractures using a less-invasive stabilization system locking plate (Synthes, Paoli, Pennsylvania). Six fractures were closed and 14 were open (6 grade IIIa, 2 grade IIIb, 4 grade II, and 2 grade I, according to the Gustilo classification). When imaging studies confirmed bone union, the plates and screws were removed in the outpatient clinic. Average time of follow-up was 23 months (range, 12-47 months). All fractures achieved union. Median time to union was 19 weeks (range, 12-40 weeks) for the proximal fractures and 22 weeks (range, 12-42 weeks) for the distal fractures. Functional results were excellent in 17 patients and good in 3. Delayed union of the fracture occurred in 2 patients. All patients' radiographs showed normal alignment. No rotational deformities and leg shortening were seen. No incidences of deep infection or implant failures occurred. Minor screw tract infection occurred in 2 patients. A new 1-stage protocol using supercutaneous plating as a definitive fixator for segmental tibial fractures is less invasive, has a lower cost, and has a shorter hospitalization time. Surgeons can achieve good reduction, soft tissue reconstruction, stable fixation, and high union rates using supercutaneous plating. The current patients obtained excellent knee and ankle joint motion and good functional outcomes and had a comfortable clinical course. Copyright 2014, SLACK Incorporated.

  16. Tibial rotational osteotomy for idiopathic torsion. A comparison of the proximal and distal osteotomy levels.

    PubMed

    Krengel, W F; Staheli, L T

    1992-10-01

    A retrospective analysis was done of 52 rotational tibial osteotomies (RTOs) performed on 35 patients with severe idiopathic tibial torsion. Thirty-nine osteotomies were performed at the proximal or midtibial level. Thirteen were performed at the distal tibial level with a technique previously described by one of the authors. Serious complications occurred in five (13%) of the proximal and in none of the distal RTOs. For severe and persisting idiopathic tibial torsion, the authors recommend correction by RTO at the distal level. Proximal level osteotomy is indicated only when a varus or valgus deformity required concurrent correction.

  17. Posterior slope of the tibial implant and the outcome of unicompartmental knee arthroplasty.

    PubMed

    Hernigou, Philippe; Deschamps, Gerard

    2004-03-01

    Laboratory studies have suggested that the sagittal displacements permitted by a knee replacement are influenced by the posterior slope of the tibial implant. The effect of the posterior slope of the tibial implant on the outcome of unicompartmental arthroplasty is not well known. The purpose of the present study was to assess the effect of the posterior slope on the long-term outcome of unicompartmental arthroplasty in knees with intact and deficient anterior cruciate ligaments. We retrospectively reviewed the results of ninety-nine unicompartmental arthroplasties after a mean duration of follow-up of sixteen years. At the time of the arthroplasty, the anterior cruciate ligament was considered to be normal in fifty knees, damaged in thirty-one, and absent in eighteen. At the most recent follow-up, we measured the posterior tibial slope and the anterior tibial translation on standing lateral radiographs. The anteroposterior stability of seventy-seven knees that had not been revised by the time of the most recent follow-up was evaluated clinically. In the group of seventy-seven knees that had not been revised by the time of the most recent follow-up, there was a significant linear relationship between anterior tibial translation (mean, 3.7 mm) and posterior tibial slope (mean, 4.3 degrees ) (p < 0.01). The mean posterior slope of the tibial implant was significantly less in the group of seventy-seven knees without loosening of the implant than it was in the group of seventeen knees with loosening of the implant (p < 0.05). Five ruptures of the anterior cruciate ligament occurred in knees in which the ligament had been considered to be normal at the time of implantation; the posterior tibial slope in these five knees was > or = 13 degrees. Clinical evaluation revealed normal or nearly normal anteroposterior stability at the time of the most recent follow-up in all sixty-six unrevised knees in which the anterior cruciate ligament had been present at the time of

  18. Immediate effects of modified landing pattern on a probabilistic tibial stress fracture model in runners.

    PubMed

    Chen, T L; An, W W; Chan, Z Y S; Au, I P H; Zhang, Z H; Cheung, R T H

    2016-03-01

    Tibial stress fracture is a common injury in runners. This condition has been associated with increased impact loading. Since vertical loading rates are related to the landing pattern, many heelstrike runners attempt to modify their footfalls for a lower risk of tibial stress fracture. Such effect of modified landing pattern remains unknown. This study examined the immediate effects of landing pattern modification on the probability of tibial stress fracture. Fourteen experienced heelstrike runners ran on an instrumented treadmill and they were given augmented feedback for landing pattern switch. We measured their running kinematics and kinetics during different landing patterns. Ankle joint contact force and peak tibial strains were estimated using computational models. We used an established mathematical model to determine the effect of landing pattern on stress fracture probability. Heelstrike runners experienced greater impact loading immediately after landing pattern switch (P<0.004). There was an increase in the longitudinal ankle joint contact force when they landed with forefoot (P=0.003). However, there was no significant difference in both peak tibial strains and the risk of tibial stress fracture in runners with different landing patterns (P>0.986). Immediate transitioning of the landing pattern in heelstrike runners may not offer timely protection against tibial stress fracture, despite a reduction of impact loading. Long-term effects of landing pattern switch remains unknown. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. How does tibial cartilage volume relate to symptoms in subjects with knee osteoarthritis?

    PubMed Central

    Wluka, A; Wolfe, R; Stuckey, S; Cicuttini, F

    2004-01-01

    Background: No consistent relationship between the severity of symptoms of knee osteoarthritis (OA) and radiographic change has been demonstrated. Objectives: To determine the relationship between symptoms of knee OA and tibial cartilage volume, whether pain predicts loss of cartilage in knee OA, and whether change in cartilage volume over time relates to change in symptoms over the same period. Method: 132 subjects with symptomatic, early (mild to moderate) knee OA were studied. At baseline and 2 years later, participants had MRI scans of their knee and completed questionnaires quantifying symptoms of knee OA (knee-specific WOMAC: pain, stiffness, function) and general physical and mental health (SF-36). Tibial cartilage volume was determined from the MRI images. Results: Complete data were available for 117 (89%) subjects. A weak association was found between tibial cartilage volume and symptoms at baseline. The severity of the symptoms of knee OA at baseline did not predict subsequent tibial cartilage loss. However, weak associations were seen between worsening of symptoms of OA and increased cartilage loss: pain (rs = 0.28, p = 0.002), stiffness (rs = 0.17, p = 0.07), and deterioration in function (rs = 0.21, p = 0.02). Conclusion: Tibial cartilage volume is weakly associated with symptoms in knee OA. There is a weak association between loss of tibial cartilage and worsening of symptoms. This suggests that although cartilage is not a major determinant of symptoms in knee OA, it does relate to symptoms. PMID:14962960

  20. Prediction of Tibial Rotation Pathologies Using Particle Swarm Optimization and K-Means Algorithms.

    PubMed

    Sari, Murat; Tuna, Can; Akogul, Serkan

    2018-03-28

    The aim of this article is to investigate pathological subjects from a population through different physical factors. To achieve this, particle swarm optimization (PSO) and K-means (KM) clustering algorithms have been combined (PSO-KM). Datasets provided by the literature were divided into three clusters based on age and weight parameters and each one of right tibial external rotation (RTER), right tibial internal rotation (RTIR), left tibial external rotation (LTER), and left tibial internal rotation (LTIR) values were divided into three types as Type 1, Type 2 and Type 3 (Type 2 is non-pathological (normal) and the other two types are pathological (abnormal)), respectively. The rotation values of every subject in any cluster were noted. Then the algorithm was run and the produced values were also considered. The values of the produced algorithm, the PSO-KM, have been compared with the real values. The hybrid PSO-KM algorithm has been very successful on the optimal clustering of the tibial rotation types through the physical criteria. In this investigation, Type 2 (pathological subjects) is of especially high predictability and the PSO-KM algorithm has been very successful as an operation system for clustering and optimizing the tibial motion data assessments. These research findings are expected to be very useful for health providers, such as physiotherapists, orthopedists, and so on, in which this consequence may help clinicians to appropriately designing proper treatment schedules for patients.

  1. Effect of ACL Transection on Internal Tibial Rotation in an in Vitro Simulated Pivot Landing

    PubMed Central

    Oh, Youkeun K.; Kreinbrink, Jennifer L.; Ashton-Miller, James A.; Wojtys, Edward M.

    2011-01-01

    Background: The amount of resistance provided by the ACL (anterior cruciate ligament) to axial tibial rotation remains controversial. The goal of this study was to test the primary hypotheses that ACL transection would not significantly affect tibial rotation under the large impulsive loads associated with a simulated pivot landing but would increase anterior tibial translation. Methods: Twelve cadaveric knees (mean age of donors [and standard deviation] at the time of death, 65.0 ± 10.5 years) were mounted in a custom testing apparatus to simulate a single-leg pivot landing. A compound impulsive load was applied to the distal part of the tibia with compression (∼800 N), flexion moment (∼40 N-m), and axial tibial torque (∼17 N-m) in the presence of five trans-knee muscle forces. A differential variable reluctance transducer mounted on the anteromedial aspect of the ACL measured relative strain. With the knee initially in 15° of flexion, and after five combined compression and flexion moment (baseline) loading trials, six trials were conducted with the addition of either internal or external tibial torque (internal or external loading), and then six baseline trials were performed. The ACL was then sectioned, six baseline trials were repeated, and then six trials of either the internal or the external loading condition, whichever had initially resulted in the larger relative ACL strain, were carried out. Tibiofemoral kinematics were measured optoelectronically. The results were analyzed with a nonparametric Wilcoxon signed-rank test. Results: Following ACL transection, the increase in the normalized internal tibial rotation was significant but small (0.7°/N-m ± 0.3°/N-m to 0.8°/N-m ± 0.3°/N-m, p = 0.012), while anterior tibial translation increased significantly (3.8 ± 2.9 to 7.0 ± 2.9 mm, p = 0.017). Conclusions: ACL transection leads to a small increase in internal tibial rotation, equivalent to a 13% decrease in the dynamic rotational resistance

  2. Delay in weight bearing in surgically treated tibial shaft fractures is associated with impaired healing: a cohort analysis of 166 tibial fractures.

    PubMed

    Houben, I B; Raaben, M; Van Basten Batenburg, M; Blokhuis, T J

    2018-04-09

    The relation between timing of weight bearing after a fracture and the healing outcome is yet to be established, thereby limiting the implementation of a possibly beneficial effect for our patients. The current study was undertaken to determine the effect of timing of weight bearing after a surgically treated tibial shaft fracture. Surgically treated diaphyseal tibial fractures were retrospectively studied between 2007 and 2015. The timing of initial weight bearing (IWB) was analysed as a predictor for impaired healing in a multivariate regression. Totally, 166 diaphyseal tibial fractures were included, 86 cases with impaired healing and 80 with normal healing. The mean age was 38.7 years (range 16-89). The mean time until IWB was significantly shorter in the normal fracture healing group (2.6 vs 7.4 weeks, p < 0.001). Correlation analysis yielded four possible confounders: infection requiring surgical intervention, fracture type, fasciotomy and open fractures. Logistic regression identified IWB as an independent predictor for impaired healing with an odds ratio of 1.13 per week delay (95% CI 1.03-1.25). Delay in initial weight bearing is independently associated with impaired fracture healing in surgically treated tibial shaft fractures. Unlike other factors such as fracture type or soft tissue condition, early resumption of weight bearing can be influenced by the treating physician and this factor therefore has a direct clinical relevance. This study indicates that early resumption of weight bearing should be the treatment goal in fracture fixation. 3b.

  3. Canine stifle joint biomechanics associated with tibial plateau leveling osteotomy predicted by use of a computer model.

    PubMed

    Brown, Nathan P; Bertocci, Gina E; Marcellin-Little, Denis J

    2014-07-01

    To evaluate effects of tibial plateau leveling osteotomy (TPLO) on canine stifle joint biomechanics in a cranial cruciate ligament (CrCL)-deficient stifle joint by use of a 3-D computer model simulating the stance phase of gait and to compare biomechanics in TPLO-managed, CrCL-intact, and CrCL-deficient stifle joints. Computer simulations of the pelvic limb of a Golden Retriever. A previously developed computer model of the canine pelvic limb was used to simulate TPLO stabilization to achieve a tibial plateau angle (TPA) of 5° (baseline value) in a CrCL-deficient stifle joint. Sensitivity analysis was conducted for tibial fragment rotation of 13° to -3°. Ligament loads, relative tibial translation, and relative tibial rotation were determined and compared with values for CrCL-intact and CrCL-deficient stifle joints. TPLO with a 5° TPA converted cranial tibial translation to caudal tibial translation and increased loads placed on the remaining stifle joint ligaments, compared with results for a CrCL-intact stifle joint. Lateral collateral ligament load was similar, medial collateral ligament load increased, and caudal cruciate ligament load decreased after TPLO, compared with loads for a CrCL-deficient stifle joint. Relative tibial rotation after TPLO was similar to that of a CrCL-deficient stifle joint. Stifle joint biomechanics were affected by TPLO fragment rotation. In the model, stifle joint biomechanics were partially improved after TPLO, compared with CrCL-deficient stifle joint biomechanics, but TPLO did not fully restore CrCL-intact stifle joint biomechanics. Overrotation of the tibial fragment negatively influenced stifle joint biomechanics by increasing caudal tibial translation.

  4. Intraoperative study on anthropometry and gender differences of the proximal tibial plateau at the arthroplasty resection surface.

    PubMed

    Yang, Bo; Yu, Jiakuo; Gong, Xi; Chen, Lianxu; Wang, Yongjian; Wang, Jian; Wang, Haijun; Zhang, Jiying

    2014-01-01

    The tibial plateau is asymmetric with a larger medial plateau. We observed from clinical practice that the shape of the tibial plateau does not always present a larger medial plateau. Tibial plateau also showed other shapes. The purpose of this study was to analyze the anthropometric data of the proximal tibia in a large group of Chinese patients undergoing total knee arthroplasty and to investigate the morphology of the resected proximal tibial surface and its gender differences. A total of 822 knees (164 males, 658 females) from the Chinese population were measured intraoperatively for medial anteroposterior (MAP) and lateral anteroposterior (LAP) dimensions of the resected proximal tibial surface. The difference of MAP and LAP (DML) was also calculated as MAP minus LAP. We then classified the data into three groups based on the DML (<-2, -2 to 2, and >2 mm) to analyze the morphology of the proximal tibia and its distribution between male and female. The shape of proximal tibial plateau was of three types: larger medial plateau type, symmetric type, and larger lateral plateau type. There were significant differences between males and females in relation to the shape distribution of the proximal tibial plateau (P < 0.05). Most of the proximal tibial plateau was asymmetric, with 517 of 822 (62.9%) tibia having a DML >2 mm and 120 of 822 (14.6%) tibia having a DML<-2 mm. Only 185 of 822 (22.5%) tibia had a DML between -2 and 2 mm. The results of this study can be used as a guideline to design tibial components with different DMLs to better match the different anthropometry of the resected tibial surface.

  5. Comparison of the primary stability of different tibial baseplate concepts to retain both cruciate ligaments during total knee arthroplasty.

    PubMed

    Nowakowski, Andrej M; Stangel, Melanie; Grupp, Thomas M; Valderrabano, Victor

    2013-10-01

    A novel tibial baseplate design (Transversal Support Tibial Plateau) as a new treatment concept for bi-cruciate retaining total knee arthroplasty is evaluated for mechanical stability and compared to other tibial baseplate designs. This concept should provide better primary stability and thus, less subsidence, than implantation of two separate unicondylar tibial baseplates. Different baseplates were implanted into synthetic bone specimens (Sawbones® Pacific Research Laboratories, Inc., Washington, USA), all uncemented. Using a standardized experimental setup, subsidence was achieved, enabling comparison of the models regarding primary stability. Overall implant subsidence was significantly increased for the two separate unicondylar tibial baseplates versus the new Transversal Support Tibial Plateau concept, which showed comparable levels to a conventional tibial baseplate. Reduced subsidence results in better primary stability. Linking of two separate baseplates appears to provide increased primary stability in terms of bony fixation, comparable to that of a conventional single tibial baseplate. © 2013. Published by Elsevier Ltd. All rights reserved.

  6. The medial tibial stress syndrome. A cause of shin splints.

    PubMed

    Mubarak, S J; Gould, R N; Lee, Y F; Schmidt, D A; Hargens, A R

    1982-01-01

    The medial tibial stress syndrome is a symptom complex seen in athletes who complain of exercise-induced pain along the distal posterior-medial aspect of the tibia. Intramuscular pressures within the posterior compartments of the leg were measured in 12 patients with this disorder. These pressures were not elevated and therefore this syndrome is a not a compartment syndrome. Available information suggests that the medial tibial stress syndrome most likely represents a periostitis at this location of the leg.

  7. Metachronous Bilateral Posterior Tibial Artery Aneurysms in Ehlers-Danlos Syndrome Type IV

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hagspiel, Klaus D., E-mail: kdh2n@virginia.edu; Bonatti, Hugo; Sabri, Saher

    2011-04-15

    Ehlers-Danlos syndrome type IV is a life-threatening genetic connective tissue disorder. We report a 24-year-old woman with EDS-IV who presented with metachronous bilateral aneurysms/pseudoaneurysms of the posterior tibial arteries 15 months apart. Both were treated successfully with transarterial coil embolization from a distal posterior tibial approach.

  8. Case report: comprehensive management of medial tibial stress syndrome

    PubMed Central

    Krenner, Bernard John

    2002-01-01

    Abstract Activity or exercise-induced leg pain is a common complication among competitive and “weekend warrior” athletes. Shin splints is a term that has been used to describe all lower leg pain as a result of activity. There are many different causes of “shin splints,” one of which is medial tibial stress syndrome, and the treating clinician must be aware of potentially serious causes of activity related leg pain. Restoring proper biomechanics to the entire kinetic chain and rehabilitation of the injured area should be the primary aim of treatment to optimize shock absorption. The role inflammation plays in medial tibial stress syndrome is controversial, but in this case, seemed to be a causative factor as symptomatology was dramatically decreased with the addition of proteolytic enzymes. Medial tibial stress syndrome can be quite difficult to treat and keeping athletes away from activities that will slow healing or aggravate the condition can be challenging. “Active” rest is the best way in which to allow proper healing while allowing the athlete to maintain their fitness. PMID:19674573

  9. [Influencing factors for trauma-induced tibial infection in underground coal mine].

    PubMed

    Meng, W Z; Guo, Y J; Liu, Z K; Li, Y F; Wang, G Z

    2016-07-20

    Objective: To investigate the influencing factors for trauma-induced tibial infection in underground coal mine. Methods: A retrospective analysis was performed for the clinical data of 1 090 patients with tibial fracture complicated by bone infection who were injured in underground coal mine and admitted to our hospital from January 1995 to August 2015, including the type of trauma, injured parts, severity, and treatment outcome. The association between risk factors and infection was analyzed. Results: Among the 1 090 patients, 357 had the clinical manifestations of acute and chronic bone infection, 219 had red and swollen legs with heat pain, and 138 experienced skin necrosis, rupture, and discharge of pus. The incidence rates of tibial infection from 1995 to 2001, from 2002 to 2008, and from 2009 to 2015 were 31%, 26.9%, and 20.2%, respectively. The incidence rate of bone infection in the proximal segment of the tibia was significantly higher than that in the middle and distal segments (42.1% vs 18.9%/27.1%, P <0.01) . As for patients with different types of trauma (Gustilo typing) , the patients with type III fracture had a significantly higher incidence rate of bone infection than those with type I/II infection (52.8% vs 21.8%/24.6%, P <0.01) . The incidence rates of bone infection after bone traction, internal fixation with steel plates, fixation with external fixator, and fixation with intramedullary nail were 20.7%, 43.5%, 21.4%, and 26.1%, respectively, suggesting that internal fixation with steel plates had a significantly higher incidence rate of bone infection than other fixation methods ( P <0.01) . The multivariate logistic regression analysis showed that the position of tibial fracture and type of fracture were independent risk factors for bone infection. Conclusion: There is a high incidence rate of trauma-induced tibial infection in workers in underground coal mine. The position of tibial fracture and type of fracture are independent risk factors

  10. Magnitude of cement-device interfacial stresses with and without tibial stemming: impact of BMI.

    PubMed

    Gopalakrishnan, Ananthkrishnan; Hedley, Anthony Keith; Kester, Mark A

    2011-03-01

    Patients expect their total knee arthroplasty to relieve pain and to be long lasting. With patients becoming more active, weighing more, and living longer, this expectation becomes increasingly more difficult to fulfill. Patients who are obese and active put greater loads on their implants and may have a greater risk of failure. Although much attention has been paid to decreasing polyethylene wear, a major cause of implant failure, very little research focus has been directed to elucidate other measures to reduce failure, such as the efficacy of prophylactic stemming of the tibial tray. This study explored whether additional mechanical support for tibial base plates would help reduce bone cement stresses in heavy patients, who, like patients with a high activity level, put added stress on their implants. A tibial base plate with a 12-mm-diameter x 50-mm-long stem was compared with the same tibial base plate with a 15-mm-diameter x 20-mm-long end cap using finite element analysis. The results indicate that the tibial base plate with a prophylactic stem significantly reduced compressive and shear stresses on the cement-device interface and therefore may help to reduce the possibility of tibial loosening in these at-risk patients. Further, such studies will aid the surgeon in educating patients and in selecting the appropriate implant strategy.

  11. Minimally-invasive plate osteosynthesis in distal tibial fractures: Results and complications.

    PubMed

    Vidović, Dinko; Matejčić, Aljoša; Ivica, Mihovil; Jurišić, Darko; Elabjer, Esmat; Bakota, Bore

    2015-11-01

    Distal tibial or pilon fractures are usually the result of combined compressive and shear forces, and may result in instability of the metaphysis, with or without articular depression, and injury to the soft tissue. The complexity of injury, lack of muscle cover and poor vascularity make these fractures difficult to treat. Surgical treatment of distal tibial fractures includes several options: external fixation, IM nailing, ORIF and minimally-invasive plate osteosynthesis (MIPO). Management of distal tibial fractures with MIPO enables preservation of soft tissue and remaining blood supply. This is a report of a series of prospectively studied closed distal tibial and pilon fractures treated with MIPO. A total of 21 patients with closed distal tibial or pilon fractures were enrolled in the study between March 2008 and November 2013 and completed follow-up. Demographic characteristics, mechanism of injury, time required for union, ankle range of motion and complications were recorded. Fractures were classified according to the AO/OTA classification. Nineteen patients were initially managed with an ankle-spanning external fixator. When the status of the soft tissue had improved and swelling had subsided enough, a definitive internal fixation with MIPO was performed. Patients were invited for follow-up examinations at 3 and 6 weeks and then at intervals of 6 to 8 weeks until 12 months. Mean age of the patients was 40.1 years (range 19-67 years). Eighteen cases were the result of high-energy trauma and three were the result of low-energy trauma. According to the AO/OTA classification there were extraarticular and intraarticular fractures, but only simple articular patterns without depression or comminution. The average time for fracture union was 19.7 weeks (range 12-38 weeks). Mean range of motion was 10° of dorsiflexion (range 5-15°) and 28.3° of plantar flexion (range 20-35°). Three cases were metalwork-related complications. Two patients underwent plate removal

  12. Theoretical discrepancy between cage size and efficient tibial tuberosity advancement in dogs treated for cranial cruciate ligament rupture.

    PubMed

    Etchepareborde, S; Mills, J; Busoni, V; Brunel, L; Balligand, M

    2011-01-01

    To calculate the difference between the desired tibial tuberosity advancement (TTA) along the tibial plateau axis and the advancement truly achieved in that direction when cage size has been determined using the method of Montavon and colleagues. To measure the effect of this difference on the final patellar tendon-tibial plateau angle (PTA) in relation to the ideal 90°. Trigonometry was used to calculate the theoretical actual advancement of the tibial tuberosity in a direction parallel to the tibial plateau that would be achieved by the placement of a cage at the level of the tibial tuberosity in the osteotomy plane of the tibial crest. The same principle was used to calculate the size of the cage that would have been required to achieve the desired advancement. The effect of the difference between the desired advancement and the actual advancement achieved on the final PTA was calculated. For a given desired advancement, the greater the tibial plateau angle (TPA), the greater the difference between the desired advancement and the actual advancement achieved. The maximum discrepancy calculated was 5.8 mm for a 12 mm advancement in a case of extreme TPA (59°). When the TPA was less than 31°, the PTA was in the range of 90° to 95°. A discrepancy does exist between the desired tibial tuberosity advancement and the actual advancement in a direction parallel to the TPA, when the tibial tuberosity is not translated proximally. Although this has an influence on the final PTA, further studies are warranted to evaluate whether this is clinically significant.

  13. Outcomes of Surgical Treatment for Anterior Tibial Stress Fractures in Athletes: A Systematic Review.

    PubMed

    Chaudhry, Zaira S; Raikin, Steven M; Harwood, Marc I; Bishop, Meghan E; Ciccotti, Michael G; Hammoud, Sommer

    2017-12-01

    Although most anterior tibial stress fractures heal with nonoperative treatment, some may require surgical management. To our knowledge, no systematic review has been conducted regarding surgical treatment strategies for the management of chronic anterior tibial stress fractures from which general conclusions can be drawn regarding optimal treatment in high-performance athletes. This systematic review was conducted to evaluate the surgical outcomes of anterior tibial stress fractures in high-performance athletes. Systematic review; Level of evidence, 4. In February 2017, a systematic review of the PubMed, MEDLINE, Cochrane, SPORTDiscus, and CINAHL databases was performed to identify studies that reported surgical outcomes for anterior tibial stress fractures. Articles meeting the inclusion criteria were screened, and reported outcome measures were documented. A total of 12 studies, published between 1984 and 2015, reporting outcomes for the surgical treatment of anterior tibial stress fractures were included in this review. All studies were retrospective case series. Collectively, surgical outcomes for 115 patients (74 males; 41 females) with 123 fractures were evaluated in this review. The overall mean follow-up was 23.3 months. The most common surgical treatment method reported in the literature was compression plating (n = 52) followed by drilling (n = 33). Symptom resolution was achieved in 108 of 123 surgically treated fractures (87.8%). There were 32 reports of complications, resulting in an overall complication rate of 27.8%. Subsequent tibial fractures were reported in 8 patients (7.0%). Moreover, a total of 17 patients (14.8%) underwent a subsequent procedure after their initial surgery. Following surgical treatment for anterior tibial stress fracture, 94.7% of patients were able to return to sports. The available literature indicates that surgical treatment of anterior tibial stress fractures is associated with a high rate of symptom resolution and return

  14. Open wedge high tibial osteotomy using three-dimensional printed models: Experimental analysis using porcine bone.

    PubMed

    Kwun, Jun-Dae; Kim, Hee-June; Park, Jaeyoung; Park, Il-Hyung; Kyung, Hee-Soo

    2017-01-01

    The purpose of this study was to evaluate the usefulness of three-dimensional (3D) printed models for open wedge high tibial osteotomy (HTO) in porcine bone. Computed tomography (CT) images were obtained from 10 porcine knees and 3D imaging was planned using the 3D-Slicer program. The osteotomy line was drawn from the three centimeters below the medial tibial plateau to the proximal end of the fibular head. Then the osteotomy gap was opened until the mechanical axis line was 62.5% from the medial border along the width of the tibial plateau, maintaining the posterior tibial slope angle. The wedge-shaped 3D-printed model was designed with the measured angle and osteotomy section and was produced by the 3D printer. The open wedge HTO surgery was reproduced in porcine bone using the 3D-printed model and the osteotomy site was fixed with a plate. Accuracy of osteotomy and posterior tibial slope was evaluated after the osteotomy. The mean mechanical axis line on the tibial plateau was 61.8±1.5% from the medial tibia. There was no statistically significant difference (P=0.160). The planned and post-osteotomy correction wedge angles were 11.5±3.2° and 11.4±3.3°, and the posterior tibial slope angle was 11.2±2.2° pre-osteotomy and 11.4±2.5° post-osteotomy. There were no significant differences (P=0.854 and P=0.429, respectively). This study showed that good results could be obtained in high tibial osteotomy by using 3D printed models of porcine legs. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. How Does Wear Rate Compare in Well-functioning Total Hip and Knee Replacements? A Postmortem Polyethylene Liner Study.

    PubMed

    Pourzal, Robin; Knowlton, Christopher B; Hall, Deborah J; Laurent, Michel P; Urban, Robert M; Wimmer, Markus A

    2016-08-01

    The longevity of total hip (THR) and knee replacements (TKR) that used historical bearing materials of gamma-in-air sterilized UHMWPE was affected more by osteolysis in THRs than in TKRs, although osteolysis remains a concern in TKRs. Therefore, the study of polyethylene wear is still of interest for the knee, particularly because few studies have investigated volumetric material loss in tibial knee inserts. For this study, a unique collection of autopsy-retrieved TKR and THR components that were well-functioning at the time of retrieval was used to compare volumetric wear differences between hip and knee polyethylene components made from identical material. The following questions were addressed: (1) How much did the hip liners wear and what wear patterns did they exhibit? (2) How much did the knee inserts wear and what wear patterns did they exhibit? (3) What is the ratio between TKR and THR wear after controlling for implantation time and patient age? We compared 23 THR components (Harris-Galante [HG] and HG II) and 20 TKR components (Miller-Galante [MG II]) that were retrieved postmortem. The components were made from the same polyethylene formulation and with similar manufacturing and sterilization (gamma-in-air) processes. Twenty-one patients (12 males, nine females) had THRs and 16 (four males, 12 females) had TKRs. Patients who had TKRs had an older (p = 0.001) average age than patients who had THRs (age, 75 years; SD, 10, versus 66 years; SD, 12, respectively). Only well-functioning components were included in this study. Therefore, implants retrieved postmortem from physically active patients and implanted for at least 2 years were considered. In addition, only normally wearing TKR components were considered, ie, those with fatigue wear (delamination) were excluded. The wear volume of each component was measured using metrology. For the tibial inserts an autonomous mathematic reconstruction method was used for quantification. The acetabular liners of the

  16. Effect of tibial tuberosity advancement on femorotibial contact mechanics and stifle kinematics.

    PubMed

    Kim, Stanley E; Pozzi, Antonio; Banks, Scott A; Conrad, Bryan P; Lewis, Daniel D

    2009-01-01

    Objective- To evaluate the effects of tibial tuberosity advancement (TTA) on femorotibial contact mechanics and 3-dimensional kinematics in cranial cruciate ligament (CrCL)-deficient stifles of dogs. Study Design- In vitro biomechanical study. Animals- Unpaired pelvic limbs from 8 dogs, weighing 28-35 kg. Methods- Digital pressure sensors placed subjacent to the menisci were used to measure femorotibial contact force, contact area, peak and mean contact pressure, and peak pressure location with the limb under an axial load of 30% body weight and a stifle angle of 135 degrees . Three-dimensional static poses of the stifle were obtained using a Microscribe digitizing arm. Each specimen was tested under normal, CrCL-deficient, and TTA-treated conditions. Repeated measures analysis of variance with a Tukey post hoc test (P<.05) was used for statistical comparison. Results- Significant disturbances to all measured contact mechanic parameters were evident after CrCL transection, which corresponded to marked cranial tibial subluxation and internal tibial rotation in the CrCL-deficient stifle. No significant differences in any contact mechanic and kinematic parameters were detected between normal and TTA-treated stifles. Conclusion- TTA eliminates craniocaudal stifle instability during simulated weight-bearing and concurrently restores femorotibial contact mechanics to normal. Clinical Relevance- TTA may mitigate the progression of stifle osteoarthritis in dogs afflicted with CrCL insufficiency by eliminating cranial tibial thrust while preserving the normal orientation of the proximal tibial articulating surface.

  17. Association between foot type and tibial stress injuries: a systematic review.

    PubMed

    Barnes, A; Wheat, J; Milner, C

    2008-02-01

    To systematically review published articles investigating the association between structural foot characteristics and tibial stress injuries, and to suggest possible future avenues of research in this area. Literature was identified, selected and appraised in accordance with the methods of a systematic review. Articles potentially relevant to the research question were identified by searching the following electronic databases: Amed, Cinahl, Index to UK theses, Medline, PubMed, Scopus, Sports discus and Web of science. Duplicates were removed and, based on the title and abstract, the full text of relevant studies were retrieved. Two reviewers independently assessed papers; this formed the basis for the inclusion of the most appropriate trials. From the 479 articles originally identified, nine were deemed appropriate for inclusion in the review. In general, specific data relating to this relationship was limited. Outcomes of the nine investigations were difficult to compare due to differing methods used across studies. Results have proved conflicting, with limited evidence found to implicate any specific foot type as a potential risk factor for tibial stress injuries. No definitive conclusions can be drawn relating foot structure or function to an increased risk of tibial stress injuries. Extremes of foot types are likely to pose an increased risk of tibial stress injuries compared to normal arched feet.

  18. Higher Rate of Revision in PFC Sigma Primary Total Knee Arthroplasty With Mismatch of Femoro-Tibial Component Sizes.

    PubMed

    Young, Simon W; Clarke, Henry D; Graves, Stephen E; Liu, Yen-Liang; de Steiger, Richard N

    2015-05-01

    Total knee arthroplasty (TKA) systems permit a degree of femoro-tibial component size mismatch. The effect of mismatched components on revision rates has not been evaluated in a large study. We reviewed 21,906 fixed-bearing PFC Sigma primary TKAs using the Australian Orthopaedic Association National Joint Replacement Registry, dividing patients into three groups: no femoro-tibial size mismatch, tibial component size > femoral component size, and femoral component > tibial component. Revision rates were higher when the femoral size was greater than the tibia, compared to both equal size (HR = 1.20 (1.00, 1.45), P = 0.047) and to tibial size greater than femoral (HR = 1.60 (1.08, 2.37), P = 0.019). Potential mechanisms to explain these findings include edge loading of polyethylene and increased tibial component stresses. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Effect of Tibial Posterior Slope on Knee Kinematics, Quadriceps Force, and Patellofemoral Contact Force After Posterior-Stabilized Total Knee Arthroplasty.

    PubMed

    Okamoto, Shigetoshi; Mizu-uchi, Hideki; Okazaki, Ken; Hamai, Satoshi; Nakahara, Hiroyuki; Iwamoto, Yukihide

    2015-08-01

    We used a musculoskeletal model validated with in vivo data to evaluate the effect of tibial posterior slope on knee kinematics, quadriceps force, and patellofemoral contact force after posterior-stabilized total knee arthroplasty. The maximum quadriceps force and patellofemoral contact force decreased with increasing posterior slope. Anterior sliding of the tibial component and anterior impingement of the anterior aspect of the tibial post were observed with tibial posterior slopes of at least 5° and 10°, respectively. Increased tibial posterior slope contributes to improved exercise efficiency during knee extension, however excessive tibial posterior slope should be avoided to prevent knee instability. Based on our computer simulation we recommend tibial posterior slopes of less than 5° in posterior-stabilized total knee arthroplasty. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. [Investigation of tibial bones of the rats exposed on board "Spacelab-2":histomorphometric analysis

    NASA Technical Reports Server (NTRS)

    Durnova, G. N.; Kaplanskii, A. S.; Morey-Holton, E. R.; Vorobeva, V. N.

    1996-01-01

    Proximal metaphyses of tibial bones from the Sprague-Dowly rats exposed in US dedicated space life sciences laboratory SLS-2 for 13-14 days and sacrificed on day 13 in microgravity and within 5 hours and 14 days following recovery were the subject of histological, histochemical, and histomorphometric analyses. After the 13-day flight of SLS-2 the rats showed initial signs of osteopenia in the spongy tissue of tibial bones, secondary spongiosis affected first. Resorption of the secondary spongiosis was consequent to enhanced resorption and inhibition of osteogenesis. In rats sacrificed within 5 hours of recovery manifestations of tibial osteopenia were more evident than in rats sacrificed during the flight. Spaceflight-induced changes in tibial spongiosis were reverse by character the amount of spongy bone was fully compensated and following 14 days of readaptation to the terrestrial gravity.

  1. Acute changes in foot strike pattern and cadence affect running parameters associated with tibial stress fractures.

    PubMed

    Yong, Jennifer R; Silder, Amy; Montgomery, Kate L; Fredericson, Michael; Delp, Scott L

    2018-05-18

    Tibial stress fractures are a common and debilitating injury that occur in distance runners. Runners may be able to decrease tibial stress fracture risk by adopting a running pattern that reduces biomechanical parameters associated with a history of tibial stress fracture. The purpose of this study was to test the hypothesis that converting to a forefoot striking pattern or increasing cadence without focusing on changing foot strike type would reduce injury risk parameters in recreational runners. Running kinematics, ground reaction forces and tibial accelerations were recorded from seventeen healthy, habitual rearfoot striking runners while running in their natural running pattern and after two acute retraining conditions: (1) converting to forefoot striking without focusing on cadence and (2) increasing cadence without focusing on foot strike. We found that converting to forefoot striking decreased two risk factors for tibial stress fracture: average and peak loading rates. Increasing cadence decreased one risk factor: peak hip adduction angle. Our results demonstrate that acute adaptation to forefoot striking reduces different injury risk parameters than acute adaptation to increased cadence and suggest that both modifications may reduce the risk of tibial stress fractures. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Association of physical activity and physical performance with tibial cartilage volume and bone area in young adults.

    PubMed

    Antony, Benny; Venn, Alison; Cicuttini, Flavia; March, Lyn; Blizzard, Leigh; Dwyer, Terence; Cross, Marita; Jones, Graeme; Ding, Changhai

    2015-10-26

    Physical activity has been recommended to patients with knee osteoarthritis for improving their symptoms. However, it is still controversial if physical activity has effects on joint structures including cartilage volume. The aim of this study was to describe the associations between physical activity and performance measured 5 years prior and tibial cartilage volume and bone area in young adults. Subjects broadly representative of the Australian population (n = 328, aged 31-41 years, female 47.3 %) were selected from the Childhood Determinants of Adult Health study. They underwent T1-weighted fat-suppressed magnetic resonance imaging (MRI) scans of their knees. Tibial bone area and cartilage volume were measured from MRI. Physical activity (measured using long international physical activity questionnaire (IPAQ)) and performance measures (long jump, leg muscle strength, physical work capacity (PWC170)) were measured 5 years prior. In multivariable analyses, total physical activity (min/week) (β: 0.30 mm(3), 95 % CI: 0.13,0.47), vigorous (β: 0.54 mm(3), 95 % CI: 0.13,0.94), moderate (β: 0.34 mm(3), 95 % CI: 0.01,0.67), walking (β: 0.40 mm(3), 95 % CI: 0.07,0.72) and IPAQ category (β: 182.9 mm(3), 95 % CI: 51.8,314.0) were positively associated with total tibial cartilage volume but not tibial bone area. PWC170, long jump and leg muscle strength were positively and significantly associated with both total tibial cartilage volume and total tibial bone area; and the associations with tibial cartilage volume decreased in magnitude but remained significant for PWC170 and long jump after further adjustment for tibial bone area. While tibial bone area is affected only by physical performance, total tibial cartilage volume can be influenced by both physical activity and performance in younger adults. The clinical significance suggests a beneficial effect for cartilage but the bone area association was restricted to performance suggesting other factors

  3. Does Tibial Slope Affect Perception of Coronal Alignment on a Standing Anteroposterior Radiograph?

    PubMed

    Schwartz, Adam J; Ravi, Bheeshma; Kransdorf, Mark J; Clarke, Henry D

    2017-07-01

    A standing anteroposterior (AP) radiograph is commonly used to evaluate coronal alignment following total knee arthroplasty (TKA). The impact of coronal alignment on TKA outcomes is controversial, perhaps due to variability in imaging and/or measurement technique. We sought to quantify the effect of image rotation and tibial slope on coronal alignment. Using a standard extramedullary tibial alignment guide, 3 cadaver legs were cut to accept a tibial tray at 0°, 3°, and 7° of slope. A computed tomography scan of the entire tibia was obtained for each specimen to confirm neutral coronal alignment. Images were then obtained at progressive 10° intervals of internal and external rotation up to 40° maximum in each direction. Images were then randomized and 5 blinded TKA surgeons were asked to determine coronal alignment. Continuous data values were transformed to categorical data (neutral [0], valgus [L], and varus [R]). Each 10° interval of external rotation of a 7° sloped tibial cut (or relative internal rotation of a tibial component viewed in the AP plane) resulted in perception of an additional 0.75° of varus. The slope of the proximal tibia bone cut should be taken into account when measuring coronal alignment on a standing AP radiograph. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. The location of the tibial accelerometer does influence impact acceleration parameters during running.

    PubMed

    Lucas-Cuevas, Angel Gabriel; Encarnación-Martínez, Alberto; Camacho-García, Andrés; Llana-Belloch, Salvador; Pérez-Soriano, Pedro

    2017-09-01

    Tibial accelerations have been associated with a number of running injuries. However, studies attaching the tibial accelerometer on the proximal section are as numerous as those attaching the accelerometer on the distal section. This study aimed to investigate whether accelerometer location influences acceleration parameters commonly reported in running literature. To fulfil this purpose, 30 athletes ran at 2.22, 2.78 and 3.33 m · s -1 with three accelerometers attached with double-sided tape and tightened to the participants' tolerance on the forehead, the proximal section of the tibia and the distal section of the tibia. Time-domain (peak acceleration, shock attenuation) and frequency-domain parameters (peak frequency, peak power, signal magnitude and shock attenuation in both the low and high frequency ranges) were calculated for each of the tibial locations. The distal accelerometer registered greater tibial acceleration peak and shock attenuation compared to the proximal accelerometer. With respect to the frequency-domain analysis, the distal accelerometer provided greater values of all the low-frequency parameters, whereas no difference was observed for the high-frequency parameters. These findings suggest that the location of the tibial accelerometer does influence the acceleration signal parameters, and thus, researchers should carefully consider the location they choose to place the accelerometer so that equivalent comparisons across studies can be made.

  5. Effect of cranial cruciate ligament deficiency, tibial plateau leveling osteotomy, and tibial tuberosity advancement on contact mechanics and alignment of the stifle in flexion.

    PubMed

    Kim, Stanley E; Pozzi, Antonio; Banks, Scott A; Conrad, Bryan P; Lewis, Daniel D

    2010-04-01

    To assess contact mechanics and 3-dimensional (3-D) joint alignment in cranial cruciate ligament (CCL)-deficient stifles before and after tibial plateau leveling osteotomy (TPLO) and tibial tuberosity advancement (TTA) with the stifle in 90 degrees of flexion. In vitro biomechanical study. Cadaveric pelvic limb pairs (n=8) from dogs weighing 28-35 kg. Contralateral limbs were assigned to receive TPLO or TTA. Digital pressure sensors were used to measure femorotibial contact area, peak and mean contact pressure, and peak pressure location with the limb under a load of 30% body weight and stifle flexion angle of 90 degrees . 3-D poses were obtained using a Microscribe digitizer. Specimens were tested under normal, CCL deficient, and treatment conditions. Significant disturbances in alignment were not observed after CCL transection, although medial contact area was 10% smaller than normal (P=.003). There were no significant differences in contact mechanics or alignment between normal and TTA conditions; TPLO induced 6 degrees varus angulation (P<.001), 26% decrease in lateral peak pressure (P=.027), and 18% increase in medial mean pressure (P=.008) when compared with normal. Cranial tibial subluxation is nominal in CCL-deficient stifles loaded in flexion. Stifle alignment and contact mechanics are not altered by TTA, whereas TPLO causes mild varus and a subsequent increase in medial compartment loading. Cranial tibial subluxation of CCL-deficient stifles may not occur during postures that load the stifle in flexion. The significance of minor changes in loading patterns after TPLO is unknown.

  6. The effect of posterior tibial slope on knee flexion in posterior-stabilized total knee arthroplasty.

    PubMed

    Shi, Xiaojun; Shen, Bin; Kang, Pengde; Yang, Jing; Zhou, Zongke; Pei, Fuxing

    2013-12-01

    To evaluate and quantify the effect of the tibial slope on the postoperative maximal knee flexion and stability in the posterior-stabilized total knee arthroplasty (TKA). Fifty-six patients (65 knees) who had undergone TKA with the posterior-stabilized prostheses were divided into the following 3 groups according to the measured tibial slopes: Group 1: ≤4°, Group 2: 4°-7° and Group 3: >7°. The preoperative range of the motion, the change in the posterior condylar offset, the elevation of the joint line, the postoperative tibiofemoral angle and the preoperative and postoperative Hospital for Special Surgery (HSS) scores were recorded. The tibial anteroposterior translation was measured using the Kneelax 3 Arthrometer at both the 30° and the 90° flexion angles. The mean values of the postoperative maximal knee flexion were 101° (SD 5), 106° (SD 5) and 113° (SD 9) in Groups 1, 2 and 3, respectively. A significant difference was found in the postoperative maximal flexion between the 3 groups (P < 0.001). However, no significant differences were found between the 3 groups in the postoperative HSS scores, the changes in the posterior condylar offset, the elevation of the joint line or the tibial anteroposterior translation at either the 30° or the 90° flexion angles. A 1° increase in the tibial slope resulted in a 1.8° flexion increment (r = 1.8, R (2) = 0.463, P < 0.001). An increase in the posterior tibial slope can significantly increase the postoperative maximal knee flexion. The tibial slope with an appropriate flexion and extension gap balance during the operation does not affect the joint stability.

  7. Bilateral periprosthetic tibial stress fracture after total knee arthroplasty: A case report.

    PubMed

    Ozdemir, Guzelali; Azboy, Ibrahim; Yilmaz, Baris

    2016-01-01

    Periprosthetic fractures around the knee after total knee arthroplasty can be seen in the femur, tibia and patella. The tibial fractures are rare cases. Our case with bilateral tibial stress fracture developed after total knee arthroplasty (TKA) is the first of its kind in the literature. 75-year-old male patient with bilateral knee osteoarthritis had not benefited from conservative treatment methods previously applied. Left TKA was applied. In the second month postoperatively, periprosthetic tibial fracture was identified and osteosynthesis was implemented with locked tibia proximal plate-screw. Bone union in 12 weeks was observed in his follow-ups. After 15 months of his first operation, TKA was applied to the right knee. Postoperatively in the second month, as in the first operation, periprosthetic tibial fracture was detected. Osteosynthesis with locking plate-screw was applied and union in 12 weeks was observed in his follow-up. He was seen mobilized independently and without support in the last control of the case made in the 24th month after the second operation. The number of TKA applications is expected to increase in the future. The incidence of periprosthetic fractures should also be expected to increase in these cases. Periprosthetic tibial fractures after TKA are rarely seen. The treatment of periprosthetic fractures around the knee after TKA can be difficult. In the case of persistent pain in the upper end of the tibia after the surgery, stress fracture should be considered. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  8. Larger medial femoral to tibial condylar dimension may trigger posterior root tear of medial meniscus.

    PubMed

    Chung, Jun Young; Song, Hyung Keun; Jung, Myung Kuk; Oh, Hyeong Tak; Kim, Joon Ho; Yoon, Ji-Sang; Min, Byoung-Hyun

    2016-05-01

    The major meniscal functions are load bearing, load distribution, and shock absorption by increasing the tibiofemoral joint (TFJ) contact area and dissipating axial loads by conversion into hoop stresses. The increased hoop strain stretches the meniscus in outward direction towards radius, causing extrusion, which is associated with the root tear and resultant degenerative osteoarthritis. Since the larger contact area of medial TFJ may increase the hoop stresses, we hypothesized that the larger medial femoral to tibial condylar dimension would contribute to the development of medial meniscus posterior root tear (MMPRT). Thus, the purpose of the study was to assess the relationship between MMPRT and medial femoral to tibial condylar dimension. A case-control study was conducted to compare medial femoral to tibial condylar dimensions of patients with complete MMPRT (n = 59) with those of demography-matched controls (n = 59) during the period from 2010 to 2013. In each patient, MRIs were reviewed and several parameters were measured including articulation width of medial femoral condyle (MFC) at 0°, 30°, 60°, and 90°, medial tibial condyle (MTC) width, degree of meniscal extrusion, and medial femoral to tibial condylar width ratio (MFC/MTC) at 0°, 30°, 60°, and 90°, respectively. Demographic and radiographic data were assessed. A larger medial femoral to tibial condylar dimension was associated with MMPRT at 0° and 30° knee angles. Patients with MFC/MTC greater than 0.9 at 0° also showed about 2.5-fold increase in the chance of MMPRT. Those with meniscal extrusion greater than 3 mm also had about 17.1 times greater chance for the presence of MMPRT accordingly. A larger medial femoral to tibial condylar dimension may be considered as one of the regional contributors to the outbreak of MMPRT, and medial femoral to tibial condylar width ratio greater than 0.9 at 0° knee angle may be considered as a significant risk factor for MMPRT. III.

  9. Posterior tibial nerve stimulation vs parasacral transcutaneous neuromodulation for overactive bladder in children.

    PubMed

    Barroso, Ubirajara; Viterbo, Walter; Bittencourt, Joana; Farias, Tiago; Lordêlo, Patrícia

    2013-08-01

    Parasacral transcutaneous electrical nerve stimulation and posterior tibial nerve stimulation have emerged as effective methods to treat overactive bladder in children. However, to our knowledge no study has compared the 2 methods. We evaluated the results of parasacral transcutaneous electrical nerve stimulation and posterior tibial nerve stimulation in children with overactive bladder. We prospectively studied children with overactive bladder without dysfunctional voiding. Success of treatment was evaluated by visual analogue scale and dysfunctional voiding symptom score, and by level of improvement of each specific symptom. Parasacral transcutaneous electrical nerve stimulation was performed 3 times weekly and posterior tibial nerve stimulation was performed once weekly. A total of 22 consecutive patients were treated with posterior tibial nerve stimulation and 37 with parasacral transcutaneous electrical nerve stimulation. There was no difference between the 2 groups regarding demographic characteristics or types of symptoms. Concerning the evaluation by visual analogue scale, complete resolution of symptoms was seen in 70% of the group undergoing parasacral transcutaneous electrical nerve stimulation and in 9% of the group undergoing posterior tibial nerve stimulation (p = 0.02). When the groups were compared, there was no statistically significant difference (p = 0.55). The frequency of persistence of urgency and diurnal urinary incontinence was nearly double in the group undergoing posterior tibial nerve stimulation. However, this difference was not statistically significant. We found that parasacral transcutaneous electrical nerve stimulation is more effective in resolving overactive bladder symptoms, which matches parental perception. However, there were no statistically significant differences in the evaluation by dysfunctional voiding symptom score, or in complete resolution of urgency or diurnal incontinence. Copyright © 2013 American Urological

  10. Predictors of failure and success of tibial interventions for critical limb ischemia.

    PubMed

    Fernandez, Nathan; McEnaney, Ryan; Marone, Luke K; Rhee, Robert Y; Leers, Steven; Makaroun, Michel; Chaer, Rabih A

    2010-10-01

    The efficacy of tibial artery endovascular intervention (TAEI) for critical limb ischemia (CLI) and particularly for wound healing is not fully defined. The purpose of this study is to determine predictors of failure and success for TAEI in the setting of CLI. All TAEI for tissue loss or rest pain (Rutherford classes 4, 5, and 6) from 2004 to 2008 were retrospectively reviewed. Clinical outcomes and patency rates were analyzed by multivariable Cox proportional hazards regression and life table analysis. One hundred twenty-three limbs in 111 patients (62% male, mean age 74) were treated. Sixty-seven percent of patients were diabetics, 55% had renal insufficiency, and 21% required hemodialysis. One hundred two limbs (83%) exhibited tissue loss; all others had ischemic rest pain. All patients underwent tibial angioplasty (PTA). Tibial excimer laser atherectomy was performed in 14% of the patients. Interventions were performed on multiple tibial vessels in 20% of limbs. Isolated tibial procedures were performed on 50 limbs (41%), while 73 patients had concurrent ipsilateral superficial femoral artery or popliteal interventions. The mean distal popliteal and tibial runoff score improved from 11.8 ± 3.6 to 6.7 ± 1.6 (P < .001), and the mean ankle-brachial index increased from 0.61 ± 0.26 to 0.85 ± 0.22 (P < .001). Surgical bypass was required in seven patients (6%). The mean follow up was 6.8 ± 6.6 months, while the 1-year primary, primary-assisted, and secondary patency rates were 33%, 50%, and 56% respectively. Limb salvage rate at 1 year was 75%. Factors found to be associated with impaired limb salvage included renal insufficiency (hazard ratio [HR] = 5.7; P = .03) and the need for pedal intervention (HR = 13.75; P = .04). TAEI in an isolated peroneal artery (odds ratio = 7.80; P = .01) was associated with impaired wound healing, whereas multilevel intervention (HR = 2.1; P = .009) and tibial laser atherectomy (HR = 3.1; P = .01) were predictors of wound healing

  11. Ipsilateral intact fibula as a predictor of tibial plafond fracture pattern and severity.

    PubMed

    Luk, Pamela C; Charlton, Timothy P; Lee, Jackson; Thordarson, David B

    2013-10-01

    The objective of this study was to determine whether there is a difference in fracture pattern and severity of comminution between tibial plafond fractures with and without associated fibular fractures using computed tomography (CT). We hypothesized that the presence of an intact fibula was predictive of increased tibial plafond fracture severity. This was a case control, radiographic review performed at a single level I university trauma center. Between November 2007 and July 2011, 104 patients with 107 operatively treated tibial pilon fractures and preoperative CT scans were identified: 70 patients with 71 tibial plafond fractures had associated fibular fractures, and 34 patients with 36 tibial plafond fractures had intact fibulas. Four criteria were compared between the 2 groups: AO/OTA classification of distal tibia fractures, Topliss coronal and sagittal fracture pattern classification, plafond region of greatest comminution, and degree of proximal extension of fracture line. The intact fibula group had greater percentages of AO/OTA classification B2 type (5.5 vs 0, P = .046) and B3 type (52.8 vs 28.2, P = .013). Conversely, the percentage of AO/OTA classification C3 type was greater in the fractured fibula group (53.5 vs 30.6, P = .025). Evaluation using the Topliss sagittal and coronal classifications revealed no difference between the 2 groups (P = .226). Central and lateral regions of the plafond were the most common areas of comminution in fractured fibula pilons (32% and 31%, respectively). The lateral region of the plafond was the most common area of comminution in intact fibula pilon fractures (42%). There was no statistically significant difference (P = .71) in degree of proximal extension of fracture line between the 2 groups. Tibial plafond fractures with intact fibulas were more commonly associated with AO/OTA classification B-type patterns, whereas those with fractured fibulas were more commonly associated with C-type patterns. An intact fibula

  12. Posterior tibial vein aneurysm presenting as tarsal tunnel syndrome.

    PubMed

    Ayad, Micheal; Whisenhunt, Anumeha; Hong, EnYaw; Heller, Josh; Salvatore, Dawn; Abai, Babak; DiMuzio, Paul J

    2015-06-01

    Tarsal tunnel syndrome is a compressive neuropathy of the posterior tibial nerve within the tarsal tunnel. Its etiology varies, including space occupying lesions, trauma, inflammation, anatomic deformity, iatrogenic injury, and idiopathic and systemic causes. Herein, we describe a 46-year-old man who presented with left foot pain. Work up revealed a venous aneurysm impinging on the posterior tibial nerve. Following resection of the aneurysm and lysis of the nerve, his symptoms were alleviated. Review of the literature reveals an association between venous disease and tarsal tunnel syndrome; however, this report represents the first case of venous aneurysm causing symptomatic compression of the nerve. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  13. The effect of high tibial osteotomy on osteoarthritis of the knee : Clinical and histological observations.

    PubMed

    Koshino, T; Tsuchiya, K

    1979-03-01

    High tibial osteotomies were performed on 136 osteoarthritic knees for correction of varus deformity. Before osteotomy all patients experienced moderate or severe pain, and the knees showed lateral thrust on weight-bearing. The patients were followed up for one to five years. Marked relief of pain was obtained in 112 knees, and the patients were satisfied with the result of operation in 122. These painless knees showed no lateral thrust, and in the majority the deformity had been adequately corrected, with post-operative femoro-tibial angles (standing) ranging from 165° to 174°. Four of 28 knees with femoro-tibial angles of 175° to 179°, when measured one year after operation, showed recurrence of varus deformity three years after osteotomy. Preoperative ranges of knee motion were well maintained after osteotomy even when arthrotomy had also been undertaken. Intra-articular assessment in two patients, several years after operation, showed that the most degenerated portions of the articular surface were completely covered by a fibrocartilagenous layer, with no bare bone.High tibial osteotomy is most effective in osteoarthritic knees with varus deformity, when correction is made to a femoro-tibial angle (standing) of 170° (10° valgus).

  14. The effect of high tibial osteotomy on osteoarthritis of the knee. Clinical and histological observations.

    PubMed

    Koshino, T; Tsuchiya, K

    1979-01-01

    High tibial osteotomies were performed on 136 osteoarthritic knees for correction of varus deformity. Before osteotomy all patients experienced moderate or severe pain, and the knees showed lateral thrust on weight-bearing. The patients were followed up for one to five years. Marked relief of pain was obtained in 112 knees, and the patients were satisfied with the result of operation in 122. These painless knees showed no lateral thrust, and in the majority the deformity had been adequately corrected, with post-operative femoro-tibial angles (standing) ranging from 165 degrees to 174 degrees. Four of 28 knees with femoro-tibial angles of 175 degrees to 179 degrees, when measured one year after operation, showed recurrence of varus deformity three years after osteotomy. Preoperative ranges of knee motion were well maintained after osteotomy even when arthrotomy had also been undertaken. Intra-articular assessment in two patients, several years after operation, showed that the most degenerated portions of the articular surface were completely covered by a fibrocartilagenous layer, with no bare bone. High tibial osteotomy is most effective in osteoarthritic knees with varus deformity, when correction is made to a femoro-tibial angle (standing) of 170 degrees (10 degrees valgus).

  15. [Operative treatment for complex tibial plateau fractures].

    PubMed

    Song, Qi-Zhi; Li, Tao

    2012-03-01

    To explore the surgical methods and clinical evaluation of complex tibial plateau fractures resulted from high-energy injuries. From March 2006 to May 2009,48 cases with complex tibial plateau fractures were treated with open reduction and plate fixation, including 37 males and 11 females, with an average age of 37 years (ranged from 18 to 63 years). According to Schatzker classification, 16 cases were type IV, 20 cases type V and 12 cases type VI. All patients were examined by X-ray flim and CT scan. The function of knee joint were evaluated according to postoperative follow-up X-ray and Knee Merchant Rating. Forty-eight patients were followed up with a mean time of 14 months. According to Knee Merchant Rating, 24 cases got excellent results, 16 cases good, 6 cases fair and 2 cases poor. Appropriate operation time, anatomical reduction, suitable bone graft and reasonable rehabilitation exercises can maximally recovery the function of knee joint.

  16. Gait retraining and incidence of medial tibial stress syndrome in army recruits.

    PubMed

    Sharma, Jagannath; Weston, Matthew; Batterham, Alan M; Spears, Iain R

    2014-09-01

    Gait retraining, comprising biofeedback and/or an exercise intervention, might reduce the risk of musculoskeletal conditions. The purpose was to examine the effect of a gait-retraining program on medial tibial stress syndrome incidence during a 26-wk basic military training regimen. A total of 450 British Army recruits volunteered. On the basis of a baseline plantar pressure variable (mean foot balance during the first 10% of stance), participants classified as at risk of developing medial tibial stress syndrome (n = 166) were randomly allocated to an intervention (n = 83) or control (n = 83) group. The intervention involved supervised gait retraining, including exercises to increase neuromuscular control and flexibility (three sessions per week) and biofeedback enabling internalization of the foot balance variable (one session per week). Both groups continued with the usual military training regimen. Diagnoses of medial tibial stress syndrome over the 26-wk regimen were made by physicians blinded to the group assignment. Data were modeled in a survival analysis using Cox regression, adjusting for baseline foot balance and time to peak heel rotation. The intervention was associated with a substantially reduced instantaneous relative risk of medial tibial stress syndrome versus control, with an adjusted HR of 0.25 (95% confidence interval, 0.05-0.53). The number needed to treat to observe one additional injury-free recruit in intervention versus control at 20 wk was 14 (11 to 23) participants. Baseline foot balance was a nonspecific predictor of injury, with an HR per 2 SD increment of 5.2 (1.6 to 53.6). The intervention was effective in reducing incidence of medial tibial stress syndrome in an at-risk military sample.

  17. Biomechanical analysis of posteromedial tibial plateau split fracture fixation.

    PubMed

    Zeng, Zhi-Min; Luo, Cong-Feng; Putnis, Sven; Zeng, Bing-Fang

    2011-01-01

    The purpose of this study was to compare the biomechanical strength of four different fixation methods for a posteromedial tibial plateau split fracture. Twenty-eight tibial plateau fractures were simulated using right-sided synthetic tibiae models. Each fracture model was randomly instrumented with one of the four following constructs, anteroposterior lag-screws, an anteromedial limited contact dynamic compression plate (LC-DCP), a lateral locking plate, or a posterior T-shaped buttress plate. Vertical subsidence of the posteromedial fragment was measured from 500 N to 1500 N during biomechanical testing, the maximum load to failure was also determined. It was found that the posterior T-shaped buttress plate allowed the least subsidence of the posteromedial fragment and produced the highest mean failure load than each of the other three constructs (P=0.00). There was no statistical significant difference between using lag screws or an anteromedial LC-DCP construct for the vertical subsidence at a 1500 N load and the load to failure (P>0.05). This study showed that a posterior-based buttress technique is biomechanically the most stable in-vitro fixation method for posteromedial split tibial plateau fractures, with AP screws and anteromedial-based LC-DCP are not as stable for this type of fracture. Copyright © 2010 Elsevier B.V. All rights reserved.

  18. Arthroscopic repair of the posterior horn of the medial meniscus with opening wedge high tibial osteotomy: surgical technique.

    PubMed

    Jung, Kwang Am; Kim, Sung Jae; Lee, Su Chan; Jeong, Jae Hoon; Song, Moon Bok; Lee, Choon Key

    2009-07-01

    Simultaneous repair of a radial tear at the tibial attachment site of the posterior horn of the medial meniscus under special circumstances requiring tibial valgus osteotomy is technically difficult. First, most patients who need an osteotomy have a narrowed medial tibiofemoral joint space. In such a situation, the pull-out suture technique is more difficult to perform than in a normal joint space. Second, pulling out suture strands that penetrate the posterior horn of the medial meniscus to the anterior tibial cortex increases the risk of transection during osteotomy. We performed a meniscus repair combined with an opening wedge tibial valgus osteotomy without complications and present our technique as a new method for use in selective cases necessitating both meniscus repair of a complete radial tear and opening wedge tibial osteotomy.

  19. Section modulus is the optimum geometric predictor for stress fractures and medial tibial stress syndrome in both male and female athletes.

    PubMed

    Franklyn, Melanie; Oakes, Barry; Field, Bruce; Wells, Peter; Morgan, David

    2008-06-01

    Various tibial dimensions and geometric parameters have been linked to stress fractures in athletes and military recruits, but many mechanical parameters have still not been investigated. Sedentary people, athletes with medial tibial stress syndrome, and athletes with stress fractures have smaller tibial geometric dimensions and parameters than do uninjured athletes. Cohort study; Level of evidence, 3. Using a total of 88 subjects, male and female patients with either a tibial stress fracture or medial tibial stress syndrome were compared with both uninjured aerobically active controls and uninjured sedentary controls. Tibial scout radiographs and cross-sectional computed tomography images of all subjects were scanned at the junction of the midthird and distal third of the tibia. Tibial dimensions were measured directly from the films; other parameters were calculated numerically. Uninjured exercising men have a greater tibial cortical cross-sectional area than do their sedentary and injured counterparts, resulting in a greater value of some other cross-sectional geometric parameters, particularly the section modulus. However, for women, the cross-sectional areas are either not different or only marginally different, and there are few tibial dimensions or geometric parameters that distinguish the uninjured exercisers from the sedentary and injured subjects. In women, the main difference between the groups was the distribution of cortical bone about the centroid as a result of the different values of section modulus. Last, medial tibial stress syndrome subjects had smaller tibial cross-sectional dimensions than did their uninjured exercising counterparts, suggesting that medial tibial stress syndrome is not just a soft-tissue injury but also a bony injury. The results show that in men, the cross-sectional area and the section modulus are the key parameters in the tibia to distinguish exercise and injury status, whereas for women, it is the section modulus only.

  20. Shock Wave-Stimulated Periosteum for Cartilage Repair

    DTIC Science & Technology

    2012-12-01

    inserted into the tibial periosteum of 6 animals to measure the actual shock waveform in the tissue for two ESW doses (energy densities). In 12 goats... tibial periosteum stimulated by one of the 2 doses of ESWs (n=6) will be harvested, 4 days post-treatment, as an autograft for implantation into one 1...locations of sensor away from the head of the ESW device. 1.b. Insert a pressure sensor into the periosteum of the right proximal tibial of6 goats to

  1. Tibial anatomy in normal small breed dogs including anisometry of various extracapsular stabilizing suture attachment sites.

    PubMed

    Witte, P G

    2015-01-01

    To investigate proximal tibial anatomy and its influence on anisometry of extracapsular stabilizing sutures in small dog breeds. Mediolateral radiographs of the femora, stifles, and tibiae of 12 small breed dogs were acquired with the stifles positioned at various angles. Measurements taken included tibial plateau angle (TPA), diaphyseal: proximal tibial angle (DPA), patellar tendon angle (PTA), Z-angle, relative tibial tuberosity width (rTTW), and the distance between six combinations of two femoral and three tibial extra-capsular stabilizing suture (ECS) attachment sites. Theoretical strain through stifle range-of-motion was recorded. The TPA (32° ± 5.8°), DPA (10.2° ± 7.3°), PTA (103.7° ± 6.2°), and Z-angle (70.4° ± 9.0°) were positively correlated with one another (R >0.7), but none were correlated with rTTW (0.93 ± 0.10). The F2-T1 combination of ECS attachment sites had lowest strain for nine stifles. The shortest attachment site separation was at a stifle flexion of 50° for nine stifles. Proximal tibial anatomy measurements could not predict optimal attachment site combination, optimal stifle angle for suture placement, or ECS strain. There is individual variation in the optimal attachment site combination and stifle angle for suture placement, which may influence consistency of outcomes with ECS.

  2. ACL Roof Impingement Revisited: Does the Independent Femoral Drilling Technique Avoid Roof Impingement With Anteriorly Placed Tibial Tunnels?

    PubMed

    Tanksley, John A; Werner, Brian C; Conte, Evan J; Lustenberger, David P; Burrus, M Tyrrell; Brockmeier, Stephen F; Gwathmey, F Winston; Miller, Mark D

    2017-05-01

    Anatomic femoral tunnel placement for single-bundle anterior cruciate ligament (ACL) reconstruction is now well accepted. The ideal location for the tibial tunnel has not been studied extensively, although some biomechanical and clinical studies suggest that placement of the tibial tunnel in the anterior part of the ACL tibial attachment site may be desirable. However, the concern for intercondylar roof impingement has tempered enthusiasm for anterior tibial tunnel placement. To compare the potential for intercondylar roof impingement of ACL grafts with anteriorly positioned tibial tunnels after either transtibial (TT) or independent femoral (IF) tunnel drilling. Controlled laboratory study. Twelve fresh-frozen cadaver knees were randomized to either a TT or IF drilling technique. Tibial guide pins were drilled in the anterior third of the native ACL tibial attachment site after debridement. All efforts were made to drill the femoral tunnel anatomically in the center of the attachment site, and the surrogate ACL graft was visualized using 3-dimensional computed tomography. Reformatting was used to evaluate for roof impingement. Tunnel dimensions, knee flexion angles, and intra-articular sagittal graft angles were also measured. The Impingement Review Index (IRI) was used to evaluate for graft impingement. Two grafts (2/6, 33.3%) in the TT group impinged upon the intercondylar roof and demonstrated angular deformity (IRI type 1). No grafts in the IF group impinged, although 2 of 6 (66.7%) IF grafts touched the roof without deformation (IRI type 2). The presence or absence of impingement was not statistically significant. The mean sagittal tibial tunnel guide pin position prior to drilling was 27.6% of the sagittal diameter of the tibia (range, 22%-33.9%). However, computed tomography performed postdrilling detected substantial posterior enlargement in 2 TT specimens. A significant difference in the sagittal graft angle was noted between the 2 groups. TT grafts were

  3. Reliability of frames of reference used for tibial component rotation in total knee arthroplasty.

    PubMed

    Page, Stephen R; Deakin, Angela H; Payne, Anthony P; Picard, Frederic

    2011-01-01

    This study evaluated seven different frames of reference used for tibial component rotation in total knee arthroplasty (TKA) to determine which ones showed good reliability between bone specimens. An optoelectronic system based around a computer-assisted surgical navigation system was used to measure and locate 34 individual anatomical landmarks on 40 tibias. Each particular frame of reference was reconstructed from a group of data points taken from the surface of each bone. The transverse axis was used as the baseline to which the other axes were compared, and the differences in angular rotation between the other six reference frames and the transverse axis were calculated. There was high variability in the tibial rotational alignment associated with all frames of reference. Of the references widely used in current TKA procedures, the tibial tuberosity axis and the anterior condylar axis had lower standard deviations (6.1° and 7.3°, respectively) than the transmalleolar axis and the posterior condylar axis (9.3° for both). In conclusion, we found high variability in the frames of reference used for tibial rotation alignment. However, the anterior condylar axis and transverse axis may warrant further tests with the use of navigation. Combining different frames of reference such as the tibial tuberosity axis, anterior condylar axis and transverse axis may reduce the range of errors found in all of these measurements.

  4. Knee braces can decrease tibial rotation during pivoting that occurs in high demanding activities.

    PubMed

    Giotis, Dimitrios; Tsiaras, Vasilios; Ristanis, Stavros; Zampeli, Franceska; Mitsionis, Grigoris; Stergiou, Nicholas; Georgoulis, Anastasios D

    2011-08-01

    The purpose of this study was to investigate whether knee braces could effectively decrease tibial rotation during high demanding activities. Using an in vivo three-dimensional kinematic analysis, 21 physically active, healthy, male subjects were evaluated. Each subject performed two tasks that were used extensively in the literature because they combine increased rotational and translational loads on the knee, (1) descending from a stair and subsequent pivoting and (2) landing from a platform and subsequent pivoting under three conditions: (A) wearing a prophylactic brace (braced), (B) wearing a patellofemoral brace (sleeved), and (C) unbraced condition. In the first task, tibial rotation during the pivoting phase was significantly decreased in the braced condition as compared to the sleeved condition (P = 0.019) and the non-braced condition (P = 0.002). In the second task, the same variable was significantly decreased in the braced condition as compared to the sleeved (P = 0.001) and the unbraced condition (P < 0.001). The sleeved condition also produced significantly decreased tibial rotation with respect to the unbraced condition (P = 0.021). Bracing decreased tibial rotation in activities where increased translational and rotational forces were applied. Because knee braces decreased tibial rotation, they can possibly be used with ACL-reconstructed and ACL-deficient patients to prevent such problems. Case-control study, Level III.

  5. [The geometry of the keel determines the behaviour of the tibial tray against torsional forces in total knee replacement].

    PubMed

    García David, S; Cortijo Martínez, J A; Navarro Bermúdez, I; Maculé, F; Hinarejos, P; Puig-Verdié, L; Monllau, J C; Hernández Hermoso, J A

    2014-01-01

    The keel design of the tibial tray is essential for the transmission of the majority of the forces to the peripheral bone structures, which have better mechanical proprieties, thus reducing the risk of loosening. The aim of the present study was to compare the behaviour of different tibial tray designs submitted to torsional forces. Four different tibial components were modelled. The 3-D reconstruction was made using the Mimics software. The solid elements were generated by SolidWorks. The finite elements study was done by Unigraphics. A torsional force of 6 Nm. applied to the lateral aspects of each tibial tray was simulated. The GENUTECH® tibial tray, with peripheral trabecular bone support, showed a lower displacement and less transmitted tensions under torsional forces. The results suggest that a tibial tray with more peripheral support behaves mechanically better than the other studied designs. Copyright © 2013 SECOT. Published by Elsevier Espana. All rights reserved.

  6. Does lateral versus medial exposure influence total knee tibial component final external rotation? A CT based study.

    PubMed

    Passeron, D; Gaudot, F; Boisrenoult, P; Fallet, L; Beaufils, P

    2009-10-01

    A previous study demonstrated that performing a total knee arthroplasty through a lateral approach including anterior tibial tuberosity (ATT) osteotomy (refixed in its original position) presented numerous advantages: correcting the preoperative patella lateral tilt and improving postoperative patella tracking. We hypothesized that these improvements in patella centering were, at least in part, due to an increased external rotation of the tibial component. Postoperative scannographic studies were, therefore, undertaken to measure tibial component rotation and analyze the results according the medial and lateral exposure used. Rotational positioning of the tibial component is influenced by the lateral or medial approach selected at surgery. Forty-five CAT scans, performed according to the protocol criteria of the French Hip and Knee Society (SFHG), were studied 3 months postoperatively: 15 knees operated through the lateral approach and 30 knees operated through a standard medial approach. The total knee utilized in all these cases was a posteriorly stabilized, fixed-bearing, design. We measured first the angle formed between the perpendicular to the transverse axis of the tibial component and the axis joining the ATT to the center of the knee; second we also measured the coronal distance between the center of the component and the anterior tibial tuberosity (ATT). In the group using the medial approach, the lateral position of the ATT was 7 + or - 3mm with a rotation angle of 18 degrees . In the group using the lateral approach these measurements were respectively 1 + or - 4mm and 2 degrees (p<0.0001). External rotation of the tibial component is substantially increased by the lateral approach compared to the medial approach. Better exposure of the lateral tibial plateau is probably responsible of this difference. This increased external rotation improves postoperative patella tracking. Prospective; comparative; non-randomized study; level 3. 2009 Elsevier Masson

  7. Reconstruction of bilateral tibial aplasia and split hand-foot syndrome in a father and daughter.

    PubMed

    Al Kaissi, Ali; Ganger, Rudolf; Klaushofer, Klaus; Grill, Franz

    2014-01-01

    Tibial aplasia is of heterogeneous aetiology, the majority of reports are sporadic. We describe the reconstruction procedures in two subjects - a daughter and father manifested autosomal dominant (AD) inheritance of the bilateral tibial aplasia and split hand-foot syndrome. Reconstruction of these patients required multiple surgical procedures and orthoprosthesis was mandatory. The main goal of treatment was to achieve walking. Stabilization of the ankle joint by fibular-talar-chondrodesis on both sides, followed by bilateral Brown-procedure at the knee joint level has been applied accordingly. The outcome was with improved function of the deformed limbs and walking was achieved with simultaneous designation of orthotic fitting. This is the first study encompassing the diagnosis and management of a father and daughter with bilateral tibial aplasia associated with variable split hand/foot deformity without foot ablation. Our patients showed the typical AD pattern of inheritance of split-hand/foot and tibial aplasia.

  8. Return to Sport After Tibial Shaft Fractures

    PubMed Central

    Robertson, Greg A. J.; Wood, Alexander M.

    2015-01-01

    Context: Acute tibial shaft fractures represent one of the most severe injuries in sports. Return rates and return-to-sport times after these injuries are limited, particularly with regard to the outcomes of different treatment methods. Objective: To determine the current evidence for the treatment of and return to sport after tibial shaft fractures. Data Sources: OVID/MEDLINE (PubMed), EMBASE, CINAHL, Cochrane Collaboration Database, Web of Science, PEDro, SPORTDiscus, Scopus, and Google Scholar were all searched for articles published from 1988 to 2014. Study Selection: Inclusion criteria comprised studies of level 1 to 4 evidence, written in the English language, that reported on the management and outcome of tibial shaft fractures and included data on either return-to-sport rate or time. Studies that failed to report on sporting outcomes, those of level 5 evidence, and those in non–English language were excluded. Study Design: Systematic review. Level of Evidence: Level 4. Data Extraction: The search used combinations of the terms tibial, tibia, acute, fracture, athletes, sports, nonoperative, conservative, operative, and return to sport. Two authors independently reviewed the selected articles and created separate data sets, which were subsequently combined for final analysis. Results: A total of 16 studies (10 retrospective, 3 prospective, 3 randomized controlled trials) were included (n = 889 patients). Seventy-six percent (672/889) of the patients were men, with a mean age of 27.7 years. Surgical management was assessed in 14 studies, and nonsurgical management was assessed in 8 studies. Return to sport ranged from 12 to 54 weeks after surgical intervention and from 28 to 182 weeks after nonsurgical management (mean difference, 69.5 weeks; 95% CI, –83.36 to −55.64; P < 0.01). Fractures treated surgically had a return-to-sport rate of 92%, whereas those treated nonsurgically had a return rate of 67% (risk ratio, 1.37; 95% CI, 1.20 to 1.57; P < 0

  9. Disentangled solid state and metastable polymer melt; a solvent free route to high-modulus high-strength tapes and films of UHMWPE

    NASA Astrophysics Data System (ADS)

    Rastogi, Sanjay

    2013-03-01

    Ultra High Molecular Weight Polyethylene (UHMWPE) having average molar mass greater than a million g/mol is an engineering polymer. Due to its light-weight, high abrasion resistance and biocompatibility it is used for demanding applications such as body armour, prostheses etc. At present, because of its high melt viscosity to achieve the uniaxial/biaxial properties in the form of fibers/films the polymer is processed via solution route where nearly 95wt% of the solvent is used to process 5wt% of the polymer. In past several attempts have been made to process the polymer without using any solvent. However, compared to the solvent processing route the achieved mechanical properties were rather poor. Here we show that by controlled synthesis it is feasible to obtain UHMWPE that could be processed free of solvent to make uniaxial tapes and biaxial films, having unprecedented mechanical properties, exceeding that of the solution spun fibers. We address some of the fundamental aspects of chemistry, physics, rheology and processing for the development of desired morphological features to achieve the ultimate mechanical properties in tapes and films. The paper will also address the metastable melt state obtained on melting of the disentangled crystals and its implication on rheology in linear and nonlinear viscoelastic region. Solid state NMR studies will be applied to establish disentangled state in solid state to the polymerisation conditions. References: Macromolecules 2011, 44(14), 5558-5568; Nature Materials 2005, 4, 635-641; Phys Rev Lett 2006, 96(21), 218303-218205. The authors acknowledge financial support by the Dutch Polymer Institute.

  10. Analysis of Knee Joint Line Obliquity after High Tibial Osteotomy.

    PubMed

    Oh, Kwang-Jun; Ko, Young Bong; Bae, Ji Hoon; Yoon, Suk Tae; Kim, Jae Gyoon

    2016-11-01

    The aim of this study was to evaluate which lower extremity alignment (knee and ankle joint) parameters affect knee joint line obliquity (KJLO) in the coronal plane after open wedge high tibial osteotomy (OWHTO). Overall, 69 knees of patients that underwent OWHTO were evaluated using radiographs obtained preoperatively and from 6 weeks to 3 months postoperatively. We measured multiple parameters of knee and ankle joint alignment (hip-knee-ankle angle [HKA], joint line height [JLH], posterior tibial slope [PS], femoral condyle-tibial plateau angle [FCTP], medial proximal tibial angle [MPTA], mechanical lateral distal femoral angle [mLDFA], KJLO, talar tilt angle [TTA], ankle joint obliquity [AJO], and the lateral distal tibial ground surface angle [LDTGA]; preoperative [-pre], postoperative [-post], and the difference between -pre and -post values [-Δ]). We categorized patients into two groups according to the KJLO-post value (the normal group [within ± 4 degrees, 56 knees] and the abnormal group [greater than ± 4 degrees, 13 knees]), and compared their -pre parameters. Multiple logistic regression analysis was used to examine the contribution of the -pre parameters to abnormal KJLO-post. The mean HKA-Δ (-9.4 ± 4.7 degrees) was larger than the mean KJLO-Δ (-2.1 ± 3.2 degrees). The knee joint alignment parameters (the HKA-pre, FCTP-pre) differed significantly between the two groups ( p  < 0.05). In addition, the HKA-pre (odds ratio [OR] = 1.27, p  = 0.006) and FCTP-pre (OR = 2.13, p  = 0.006) were significant predictors of abnormal KJLO-post. However, -pre ankle joint parameters (TTA, AJO, and LDTGA) did not differ significantly between the two groups and were not significantly associated with the abnormal KJLO-post. The -pre knee joint alignment and knee joint convergence angle evaluated by HKA-pre and FCTP-pre angle, respectively, were significant predictors of abnormal KJLO after OWHTO. However, -pre ankle joint

  11. Study of the anatomy of the tibial nerve and its branches in the distal medial leg.

    PubMed

    Torres, André Leal Gonçalves; Ferreira, Marcus Castro

    2012-01-01

    Determine, through dissection in fresh cadavers, the topographic anatomy of the tibial nerve and its branches at the ankle, in relation to the tarsal tunnel. Bilateral dissections were performed on 26 fresh cadavers and the locations of the tibial nerve bifurcation and its branches were measured in millimeters. For the calcaneal branches, the amount and their respective nerves of origin were also analyzed. The tibial nerve bifurcation occurred under the tunnel in 88% of the cases and proximally in 12%. As for the calcaneal branches, the medial presented with one (58%), two (34%) and three (8%) branches, with the most common source occurring in the tibial nerve (90%) and the lower with a single branch per leg and lateral plantar nerve as the most common origin (70%). Level of Evidence, V Expert opinion .

  12. The effects of sectioning the spring ligament on rearfoot stability and posterior tibial tendon efficiency.

    PubMed

    Jennings, Meagan M; Christensen, Jeffery C

    2008-01-01

    Posterior tibial tendon insufficiency has been implicated as a cause of adult acquired flatfoot. Multiple theories are debated as to whether or not a flatfoot deformity develops secondary to insufficiency of the posterior tibial tendon or of the ligamentous structures such as the spring ligament complex. This cadaveric study was undertaken in an attempt to determine the effect that sectioning the spring ligament complex has on foot stability, and whether engagement of the posterior tibial tendon would be able to compensate for the loss of the spring ligament complex. A 3-dimensional kinematic system and a custom-loading frame were used to quantify rotation about the talus, navicular, and calcaneus in 5 cadaveric specimens, before and after sectioning the spring ligament complex, while incremental tension was applied to the posterior tibial tendon. This study demonstrated that sectioning the spring ligament complex created instability in the foot for which the posterior tibial tendon was unable to compensate. Sectioning the spring ligament complex also produced significant changes in talar, navicular, and calcaneal rotations. During simulated midstance, the navicular plantarflexed, adducted, and everted; the talar head plantarflexed, adducted, and inverted; and the calcaneus plantarflexed, abducted, and everted, after sectioning the spring ligament complex. The results of this study indicate that the spring ligament complex is the major stabilizer of the arch during midstance and that the posterior tibial tendon is incapable of fully accommodating for its insufficiency, suggesting that the spring ligament complex should be evaluated and, if indicated, repaired in flatfoot reconstruction. 5.

  13. Survivorship comparison of all-polyethylene and metal-backed tibial components in cruciate-substituting total knee arthroplasty--Chinese experience.

    PubMed

    Shen, Bin; Yang, Jing; Zhou, Zongke; Kang, Pengde; Wang, Liao; Pei, Fuxing

    2009-10-01

    Considering its cost saving, the all-polyethylene tibial component is of potential interest in developing countries like China. But to our knowledge, a survivorship comparison of all-polyethylene and metal-backed tibial components in posterior cruciate ligament-substituting total knee arthroplasty (PS-TKA) has not been studied in China previously. Using survivorship analysis, we have studied the midterm outcome of 34 cemented PS-TKA using an all-polyethylene tibial component and of 34 cemented PS-TKA using a metal-backed tibial component which has an identical articular surface with all-polyethylene tibial components. All operations were performed by the same group of surgeons; 58 patients underwent a unilateral operation and five patients a bilateral operation. These patients had a mean follow-up of 5.9 years (range: 5-7 years); three patients were lost to follow-up and one was revised for infection. No significant difference between the two groups was reported regarding HSS scores, ROM, clinical and radiographic parameters measured and survival rates. Although the Asian lifestyle includes more squatting and bending of the knee, the results of this series of TKA using all-polyethylene tibial components in Chinese people are comparable to the satisfactory results of other reported all-polyethylene series whose patients are mainly Western people. Considering its cost saving and excellent clinical result, the all-polyethylene tibial component is of potential interest in developing countries.

  14. Effect of tibial plateau leveling osteotomy on femorotibial contact mechanics and stifle kinematics.

    PubMed

    Kim, Stanley E; Pozzi, Antonio; Banks, Scott A; Conrad, Bryan P; Lewis, Daniel D

    2009-01-01

    To evaluate the effects of tibial plateau leveling osteotomy (TPLO) on femorotibial contact mechanics and 3-dimensional (3D) kinematics in cranial cruciate ligament (CrCL)-deficient stifles of dogs. In vitro biomechanical study. Unpaired pelvic limbs from 8 dogs, weighing 28-35 kg. Digital pressure sensors placed subjacent to the menisci were used to measure femorotibial contact force, contact area, peak and mean contact pressure, and peak pressure location with the limb under an axial load of 30% body weight and a stifle angle of 135 degrees. Three-dimensional static poses of the stifle were obtained using a Microscribe digitizing arm. Each specimen was tested under normal, CrCL-deficient, and TPLO-treated conditions. Repeated measures analysis of variance with a Tukey post hoc test (P<.05) was used for statistical comparison. Significant disturbances to all measured contact mechanical variables were evident after CrCL transection, which corresponded to marked cranial tibial subluxation and increased internal tibial rotation in the CrCL-deficient stifle. No significant differences in 3D femorotibial alignment were observed between normal and TPLO-treated stifles; however, femorotibial contact area remained significantly smaller and peak contact pressures in both medial and lateral stifle compartments were positioned more caudally on the tibial plateau, when compared with normal. Whereas TPLO eliminates craniocaudal stifle instability during simulated weight bearing, the procedure fails to concurrently restore femorotibial contact mechanics to normal. Progression of stifle osteoarthritis in dogs treated with TPLO may be partly the result of abnormal stifle contact mechanics induced by altering the orientation of the proximal tibial articulating surface.

  15. Osteogenic Protein-1 (Bone Morphogenetic Protein-7) in the Treatment of Tibial Nonunions

    PubMed Central

    FRIEDLAENDER, GARY E.; PERRY, CLAYTON R.; DEAN COLE, J.; COOK, STEPHEN D.; CIERNY, GEORGE; MUSCHLER, GEORGE F.; ZYCH, GREGORY A.; CALHOUN, JASON H.; LAFORTE, AMY J.; YIN, SAMUEL

    2005-01-01

    Background: The role of bone morphogenetic proteins (BMPs) in osseous repair has been demonstrated in numerous animal models. Recombinant human osteogenic protein-1 (rhOP-1 or BMP-7) has now been produced and was evaluated in a clinical trial conducted under a Food and Drug Administration approved Investigational Device Exemption to establish both the safety and efficacy of this BMP in the treatment of tibial nonunions. The study also compared the clinical and radiographic results with this osteogenic molecule and those achieved with fresh autogenous bone. Materials and Methods: One hundred and twenty-two patients (with 124 tibial nonunions) were enrolled in a controlled, prospective, randomized, partially blinded, multi-center clinical trial between February, 1992, and August, 1996, and were followed at frequent intervals over 24 months. Each patient was treated by insertion of an intramedullary rod, accompanied by rhOP-1 in a type I collagen carrier or by fresh bone autograft. Assessment criteria included the severity of pain at the fracture site, the ability to walk with full weight-bearing, the need for surgical re-treatment of the nonunion during the course of this study, plain radiographic evaluation of healing, and physician satisfaction with the clinical course. In addition, adverse events were recorded, and sera were screened for antibodies to OP-1 and type-I collagen at each outpatient visit. Results: At 9 months following the operative procedures (the primary end-point of this study), 81% of the OP-1-treated nonunions (n = 63) and 85% of those receiving autogenous bone (n = 61) were judged by clinical criteria to have been treated successfully (p = 0.524). By radiographic criteria, at this same time point, 75% of those in the OP-1-treated group and 84% of the autograft-treated patients had healed fractures (p = 0.218). These clinical results continued at similar levels of success throughout 2 years of observation, and there was no statistically

  16. Tibial plateau fracture after primary anatomic double-bundle anterior cruciate ligament reconstruction: a case report.

    PubMed

    Gobbi, Alberto; Mahajan, Vivek; Karnatzikos, Georgios

    2011-05-01

    Tibial plateau fracture after primary anatomic double-bundle anterior cruciate ligament (ACL) reconstruction is rare. To our knowledge, this is the first case report of a tibial plateau fracture after primary anatomic double-bundle ACL reconstruction. In our patient the tibial plateau fracture occurred after a torsional injury to the involved extremity. The fracture occurred 4.5 years after the ACL reconstruction. The fracture was intra-articular Schatzker type IV and had a significant displacement. The patient was treated operatively by open reduction-internal fixation. He recovered well. Copyright © 2011 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  17. Negative pressure wound therapy for Gustilo Anderson grade IIIb open tibial fractures.

    PubMed

    Park, Chul Hyun; Shon, Oog Jin; Kim, Gi Beom

    2016-09-01

    Traditionally, Gustilo Anderson grade IIIb open tibial fractures have been treated by initial wide wound debridement, stabilization of fracture with external fixation, and delayed wound closure. The purpose of this study is to evaluate the clinical and radiological results of staged treatment using negative pressure wound therapy (NPWT) for Gustilo Anderson grade IIIb open tibial fractures. 15 patients with Gustilo Anderson grade IIIb open tibial fractures, treated using staged protocol by a single surgeon between January 2007 and December 2011 were reviewed in this retrospective study. The clinical results were assessed using a Puno scoring system for severe open fractures of the tibia at the last followup. The range of motion (ROM) of the knee and ankle joints and postoperative complication were evaluated at the last followup. The radiographic results were assessed using time to bone union, coronal and sagittal angulations and a shortening at the last followup. The mean score of Puno scoring system was 87.4 (range 67-94). The mean ROM of the knee and ankle joints was 121.3° (range 90°-130°) and 37.7° (range 15°-50°), respectively. Bone union developed in all patients and the mean time to union was 25.3 weeks (range 16-42 weeks). The mean coronal angulation was 2.1° (range 0-4°) and sagittal was 2.7° (range 1-4°). The mean shortening was 4.1 mm (range 0-8 mm). Three patients had partial flap necrosis and 1 patient had total flap necrosis. There was no superficial and deep wound infection. Staged treatment using NPWT decreased the risks of infection and requirement of flap surgeries in Gustilo Anderson grade IIIb open tibial fractures. Therefore, staged treatment using NPWT could be a useful treatment option for Gustilo Anderson grade IIIb open tibial fractures.

  18. Quantitative Comparison of the Microscopic Anatomy of the Human ACL Femoral and Tibial Entheses

    PubMed Central

    Beaulieu, Mélanie L.; Carey, Grace E.; Schlecht, Stephen H.; Wojtys, Edward M.; Ashton-Miller, James A.

    2015-01-01

    The femoral enthesis of the human anterior cruciate ligament (ACL) is known to be more susceptible to injury than the tibial enthesis. To determine whether anatomic differences might help explain this difference, we quantified the microscopic appearance of both entheses in 15 unembalmed knee specimens using light microscopy, toluidine blue stain and image analysis. The amount of calcified fibrocartilage and uncalcified fibrocartilage, and the ligament entheseal attachment angle were then compared between the femoral and tibial entheses via linear mixed-effects models. The results showed marked differences in anatomy between the two entheses. The femoral enthesis exhibited a 3.9-fold more acute ligament attachment angle than the tibial enthesis (p < 0.001), a 43% greater calcified fibrocartilage tissue area (p < 0.001), and a 226% greater uncalcified fibrocartilage depth (p < 0.001), with the latter differences being particularly pronounced in the central region. We conclude that the ACL femoral enthesis has more fibrocartilage and a more acute ligament attachment angle than the tibial enthesis, which provides insight into why it is more vulnerable to failure. PMID:26134706

  19. A Case of Nonunion Avulsion Fracture of the Anterior Tibial Eminence

    PubMed Central

    Atsumi, Satoru; Arai, Yuji; Nakagawa, Shuji; Inoue, Hiroaki; Ikoma, Kazuya; Fujiwara, Hiroyoshi; Kubo, Toshikazu

    2016-01-01

    Avulsion fracture of the anterior tibial eminence is an uncommon injury. If bone union does not occur, knee extension will be limited by impingement of the avulsed fragment and knee instability will be induced by dysfunction of the anterior cruciate ligament (ACL). This report describes a 55-year-old woman who experienced an avulsion fracture of the right anterior tibial eminence during recreational skiing. Sixteen months later, she presented at our hospital with limitation of right knee extension. Plain radiography showed nonunion of the avulsion fracture region, and arthroscopy showed that the avulsed fragment impinged the femoral intercondylar notch during knee extension. The anterior region of the bony fragment was debrided arthroscopically until the knee could be extended completely. There was no subsequent instability, and the patient was able to climb a mountain 6 months after surgery. These findings indicate that arthroscopic debridement of an avulsed fragment for nonunion of an avulsion fracture of the anterior tibial eminence is a minimally invasive and effective treatment for middle-aged and elderly patients with a low level of sports activity. PMID:27119035

  20. Study of the anatomy of the tibial nerve and its branches in the distal medial leg

    PubMed Central

    Torres, André Leal Gonçalves; Ferreira, Marcus Castro

    2012-01-01

    Objective Determine, through dissection in fresh cadavers, the topographic anatomy of the tibial nerve and its branches at the ankle, in relation to the tarsal tunnel. Methods Bilateral dissections were performed on 26 fresh cadavers and the locations of the tibial nerve bifurcation and its branches were measured in millimeters. For the calcaneal branches, the amount and their respective nerves of origin were also analyzed. Results The tibial nerve bifurcation occurred under the tunnel in 88% of the cases and proximally in 12%. As for the calcaneal branches, the medial presented with one (58%), two (34%) and three (8%) branches, with the most common source occurring in the tibial nerve (90%) and the lower with a single branch per leg and lateral plantar nerve as the most common origin (70%). Level of Evidence, V Expert opinion. PMID:24453596

  1. Quadriceps force and anterior tibial force occur obviously later than vertical ground reaction force: a simulation study.

    PubMed

    Ueno, Ryo; Ishida, Tomoya; Yamanaka, Masanori; Taniguchi, Shohei; Ikuta, Ryohei; Samukawa, Mina; Saito, Hiroshi; Tohyama, Harukazu

    2017-11-18

    Although it is well known that quadriceps force generates anterior tibial force, it has been unclear whether quadriceps force causes great anterior tibial force during the early phase of a landing task. The purpose of the present study was to examine whether the quadriceps force induced great anterior tibial force during the early phase of a landing task. Fourteen young, healthy, female subjects performed a single-leg landing task. Muscle force and anterior tibial force were estimated from motion capture data and synchronized force data from the force plate. One-way repeated measures analysis of variance and the post hoc Bonferroni test were conducted to compare the peak time of the vertical ground reaction force, quadriceps force and anterior tibial force during the single-leg landing. In addition, we examined the contribution of vertical and posterior ground reaction force, knee flexion angle and moment to peak quadriceps force using multiple linear regression. The peak times of the estimated quadriceps force (96.0 ± 23.0 ms) and anterior tibial force (111.9 ± 18.9 ms) were significantly later than that of the vertical ground reaction force (63.5 ± 6.8 ms) during the single-leg landing. The peak quadriceps force was positively correlated with the peak anterior tibial force (R = 0.953, P < 0.001). Multiple linear regression analysis showed that the peak knee flexion moment contributed significantly to the peak quadriceps force (R 2  = 0.778, P < 0.001). The peak times of the quadriceps force and the anterior tibial force were obviously later than that of the vertical ground reaction force for the female athletes during successful single-leg landings. Studies have reported that the peak time of the vertical ground reaction force was close to the time of anterior cruciate ligament (ACL) disruption in ACL injury cases. It is possible that early contraction of the quadriceps during landing might induce ACL disruption as a result of

  2. In Vivo Tibial Fit and Rotational Analysis of a Customized, Patient-Specific TKA versus Off-the-Shelf TKA.

    PubMed

    Schroeder, Lennart; Martin, Gregory

    2018-05-25

    In total knee arthroplasty (TKA), surgeons often face the decision of maximizing tibial component fit and achieving correct rotational alignment at the same time. Customized implants (CIMs) address this difficulty by aiming to replicate the anatomical joint structure, utilizing data from patient-specific knee geometry during the manufacturing. We intraoperatively compared component fit in four tibial zones of a CIM to that of three different off-the-shelf (OTS) TKA designs in 44 knees. Additionally, we assessed the rotational alignment of the tibia using computed tomography (CT)-based computer aided design model analysis. Overall the CIM device showed significantly better component fit than the OTS TKAs. While 18% of OTS designs presented an implant overhang of 3 mm or more, none of the CIM components did ( p  < 0.05). There was a larger percentage of CIMs seen with optimal fit (≤1 mm implant overhang to ≤1 mm tibial bone undercoverage) than in OTS TKAs. Also, OTS implants showed significantly more component underhang of ≥3 mm than the CIM design (37 vs. 18%). The rotational analysis revealed that 45% of the OTS tibial components showed a rotational deviation of more than 5 degrees and 4% of more than 10 degrees to a tibial rotational axis described by Cobb et al. No deviation was seen for the CIM, as the device is designed along this axis. Using the medial one-third of the tibial tubercle as the rotational landmark, 95% of the OTS trays demonstrated a rotational deviation of more than 5 degrees and 73% of more than 10 degrees compared with 73% of CIM tibial trays with more than 5 degrees and 27% with more than 10 degrees. Based on our findings, we believe that the CIM TKA provides both better rotational alignment and tibial fit without causing overhang of the tibial tray than the three examined OTS implants. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  3. Foot and ankle function after tibial overlengthening.

    PubMed

    Emara, Khaled M; Diab, Ramy Ahmed; El Ghazali, Sherif; Farouk, Amr; El Kersh, Mohamed Ahmed

    2014-01-01

    Lengthening the tibia more than 25% of its original length can be indicated for proximal femoral deficiency, poliomyelitis, or femoral infected nonunion. Such lengthening of the tibia can adversely affect the ankle or foot shape and function. The present study aimed to assess the effect of tibial lengthening of more than 25% of its original length on the foot and ankle shape and function compared with the preoperative condition. This was a retrospective study of 13 children with severe proximal focal femoral deficiency, Aitken classification type D, who had undergone limb lengthening from June 2000 to June 2008 using Ilizarov external fixators. The techniques used in tibial lengthening included lengthening without intramedullary rodding and lengthening over a nail. The foot assessment was done preoperatively, at fixator removal, and then annually for 3 years, documenting the range of motion and deformity of the ankle and subtalar joints and big toe and the navicular height, calcaneal pitch angle, and talo-first metatarsal angle. At fixator removal, all cases showed equinocavovarus deformity, with decreased ankle, subtalar, and big toe motion. The mean American Orthopedic Foot and Ankle Society score was significantly reduced. During follow-up, the range of motion, foot deformity, and American Orthopedic Foot and Ankle Society score improved, reaching nearly to the preoperative condition by 2 years of follow-up. The results of our study have shown that tibial overlengthening has an adverse effect on foot and ankle function. This effect was reversible in the patients included in the present study. Lengthening of more than 25% can be safely done after careful discussion with the patients and their families about the probable effects of lengthening on foot and ankle function. Copyright © 2014 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  4. Medial tibial stress syndrome: a critical review.

    PubMed

    Moen, Maarten H; Tol, Johannes L; Weir, Adam; Steunebrink, Miriam; De Winter, Theodorus C

    2009-01-01

    Medial tibial stress syndrome (MTSS) is one of the most common leg injuries in athletes and soldiers. The incidence of MTSS is reported as being between 4% and 35% in military personnel and athletes. The name given to this condition refers to pain on the posteromedial tibial border during exercise, with pain on palpation of the tibia over a length of at least 5 cm. Histological studies fail to provide evidence that MTSS is caused by periostitis as a result of traction. It is caused by bony resorption that outpaces bone formation of the tibial cortex. Evidence for this overloaded adaptation of the cortex is found in several studies describing MTSS findings on bone scan, magnetic resonance imaging (MRI), high-resolution computed tomography (CT) scan and dual energy x-ray absorptiometry. The diagnosis is made based on physical examination, although only one study has been conducted on this subject. Additional imaging such as bone, CT and MRI scans has been well studied but is of limited value. The prevalence of abnormal findings in asymptomatic subjects means that results should be interpreted with caution. Excessive pronation of the foot while standing and female sex were found to be intrinsic risk factors in multiple prospective studies. Other intrinsic risk factors found in single prospective studies are higher body mass index, greater internal and external ranges of hip motion, and calf girth. Previous history of MTSS was shown to be an extrinsic risk factor. The treatment of MTSS has been examined in three randomized controlled studies. In these studies rest is equal to any intervention. The use of neoprene or semi-rigid orthotics may help prevent MTSS, as evidenced by two large prospective studies.

  5. Survivorship comparison of all-polyethylene and metal-backed tibial components in cruciate-substituting total knee arthroplasty—Chinese experience

    PubMed Central

    Shen, Bin; Yang, Jing; Zhou, Zongke; Kang, Pengde; Wang, Liao

    2008-01-01

    Considering its cost saving, the all-polyethylene tibial component is of potential interest in developing countries like China. But to our knowledge, a survivorship comparison of all-polyethylene and metal-backed tibial components in posterior cruciate ligament-substituting total knee arthroplasty (PS-TKA) has not been studied in China previously. Using survivorship analysis, we have studied the midterm outcome of 34 cemented PS-TKA using an all-polyethylene tibial component and of 34 cemented PS-TKA using a metal-backed tibial component which has an identical articular surface with all-polyethylene tibial components. All operations were performed by the same group of surgeons; 58 patients underwent a unilateral operation and five patients a bilateral operation. These patients had a mean follow-up of 5.9 years (range: 5–7 years); three patients were lost to follow-up and one was revised for infection. No significant difference between the two groups was reported regarding HSS scores, ROM, clinical and radiographic parameters measured and survival rates. Although the Asian lifestyle includes more squatting and bending of the knee, the results of this series of TKA using all-polyethylene tibial components in Chinese people are comparable to the satisfactory results of other reported all-polyethylene series whose patients are mainly Western people. Considering its cost saving and excellent clinical result, the all-polyethylene tibial component is of potential interest in developing countries. PMID:18688613

  6. The effect of retained intramedullary nails on tibial bone mineral density.

    PubMed

    Allen, J C; Lindsey, R W; Hipp, J A; Gugala, Z; Rianon, N; LeBlanc, A

    2008-07-01

    Intramedullary nailing has become a standard treatment for adult tibial shaft fractures. Retained intramedullary nails have been associated with stress shielding, although their long-term effect on decreasing tibial bone mineral density is currently unclear. The purpose of this study was to determine if retained tibial intramedullary nails decrease tibial mineral density in patients with successfully treated fractures. Patients treated with statically locked intramedullary nails for isolated, unilateral tibia shaft fractures were studied. Inclusion required that fracture had healed radiographically and that the patient returned to the pre-injury activity level. Data on patient demographic, fracture type, surgical technique, implant, and post-operative functional status were tabulated. Dual energy X-ray absorptiometry was used to measure bone mineral density in selected regions of the affected tibia and the contralateral intact tibia. Image reconstruction software was employed to ensure symmetry of the studied regions. Twenty patients (mean age 43; range 22-77 years) were studied at a mean of 29 months (range 5-60 months) following intramedullary nailing. There was statistically significant reduction of mean bone mineral density in tibiae with retained intramedullary nails (1.02 g/cm(2) versus 1.06 g/cm(2); P=0.04). A significantly greater decrease in bone mineral density was detected in the reamed versus non-reamed tibiae (-7% versus +6%, respectively; P<0.05). The present study demonstrates a small, but statistically significant overall bone mineral density decrease in healed tibiae with retained nails. Intramedullary reaming appears to be a factor potentiating the reduction of tibia bone mineral density in long-term nail retention.

  7. Surgical treatment of refractory tibial stress fractures in elite dancers: a case series.

    PubMed

    Miyamoto, Ryan G; Dhotar, Herman S; Rose, Donald J; Egol, Kenneth

    2009-06-01

    Treatment of tibial stress fractures in elite dancers is centered on rest and activity modification. Surgical intervention in refractory cases has important implications affecting the dancers' careers. Refractory tibial stress fractures in dancers can be treated successfully with drilling and bone grafting or intramedullary nailing. Case series; Level of evidence, 4. Between 1992 and 2006, 1757 dancers were evaluated at a dance medicine clinic; 24 dancers (1.4%) had 31 tibial stress fractures. Of that subset, 7 (29.2%) elite dancers with 8 tibial stress fractures were treated operatively with either intramedullary nailing or drilling and bone grafting. Six of the patients were followed up closely until they were able to return to dance. One patient was available only for follow-up phone interview. Data concerning their preoperative treatment regimens, operative procedures, clinical union, radiographic union, and time until return to dance were recorded and analyzed. The mean age of the surgical patients at the time of stress fracture was 22.6 years. The mean duration of preoperative symptoms before surgical intervention was 25.8 months. Four of the dancers were male and 3 were female. All had failed nonoperative treatment regimens. Five patients (5 tibias) underwent drilling and bone grafting of the lesion, and 2 patients (3 tibias) with completed fractures or multiple refractory stress fractures underwent intramedullary nailing. Clinical union was achieved at a mean of 6 weeks and radiographic union at 5.1 months. Return to full dance activity was at an average of 6.5 months postoperatively. Surgical intervention for tibial stress fractures in dancers who have not responded to nonoperative management allowed for resolution of symptoms and return to dancing with minimal morbidity.

  8. Biomechanical Factors in Tibial Stress Fracture

    DTIC Science & Technology

    2001-08-01

    Relationship between Loading Rates and Tibial Accelerometry in Forefoot Strike Runners. Presented at the Annual American Society of Biomechanics Mtg...of the APTA, Seattle, WA, 2/99. McClay, IS, Williams, DS, and Manal, KT. Lower Extremity Mechanics of Runners with a Converted Forefoot Strike ...Management, Inc, 1998-1999 The Effect of Different Orthotic Devices on Lower Extremity Mechanics of Rearfoot and Forefoot Strikers, $3,500. Foot Management

  9. The role of fixation and bone quality on the mechanical stability of tibial knee components.

    PubMed

    Lee, R W; Volz, R G; Sheridan, D C

    1991-12-01

    Tibial component loosening remains one of the major causes of failure of cemented and noncemented total knee arthroplasties. In this study, the authors identified the role of implant design, method of fixation, and bone density as it related to implant stability. The physical properties of "good" and "bad" bone were simulated using a "good" and "bad" foam model of the proximal tibia, fabricated in the laboratory from DARO RF-100 foam. A generic tibial component permitting various fixation designs was implanted into "good" and "bad" variable density foam tibial models in both cemented and noncemented modes. The mechanical stability of the implants was determined using a Materials Testing Machine by the application of an eccentrically applied cyclic load. The micromotion (subsidence and lift-off) of the tibial implants was recorded using two Linear Variable Differential Transformers. Statistically significant differences in implant stability were recorded as a function of fixation method. The most rigid implant fixation was achieved using four peripherally placed, 6.5-mm cancellous screws. The addition of a central stem added stability only in the case of "poor" quality foam. The mechanical stability of noncemented implants related directly to the density of the foam. Implant stability was greatly enhanced in "poor" quality foam by the use of cement. The method of implant fixation and bone density are critical determinants to tibial implant stability.

  10. Combined CT-based and image-free navigation systems in TKA reduces postoperative outliers of rotational alignment of the tibial component.

    PubMed

    Mitsuhashi, Shota; Akamatsu, Yasushi; Kobayashi, Hideo; Kusayama, Yoshihiro; Kumagai, Ken; Saito, Tomoyuki

    2018-02-01

    Rotational malpositioning of the tibial component can lead to poor functional outcome in TKA. Although various surgical techniques have been proposed, precise rotational placement of the tibial component was difficult to accomplish even with the use of a navigation system. The purpose of this study is to assess whether combined CT-based and image-free navigation systems replicate accurately the rotational alignment of tibial component that was preoperatively planned on CT, compared with the conventional method. We compared the number of outliers for rotational alignment of the tibial component using combined CT-based and image-free navigation systems (navigated group) with those of conventional method (conventional group). Seventy-two TKAs were performed between May 2012 and December 2014. In the navigated group, the anteroposterior axis was prepared using CT-based navigation system and the tibial component was positioned under control of the navigation. In the conventional group, the tibial component was placed with reference to the Akagi line that was determined visually. Fisher's exact probability test was performed to evaluate the results. There was a significant difference between the two groups with regard to the number of outliers: 3 outliers in the navigated group compared with 12 outliers in the conventional group (P < 0.01). We concluded that combined CT-based and image-free navigation systems decreased the number of rotational outliers of tibial component, and was helpful for the replication of the accurate rotational alignment of the tibial component that was preoperatively planned.

  11. What are the bias, imprecision, and limits of agreement for finding the flexion-extension plane of the knee with five tibial reference lines?

    PubMed

    Brar, Abheetinder S; Howell, Stephen M; Hull, Maury L

    2016-06-01

    Internal-external (I-E) malrotation of the tibial component is associated with poor function after total knee arthroplasty (TKA). Kinematically aligned (KA) TKA uses a functionally defined flexion-extension (F-E) tibial reference line, which is parallel to the F-E plane of the extended knee, to set I-E rotation of the tibial component. Sixty-two, three-dimensional bone models of normal knees were analyzed. We computed the bias (mean), imprecision (±standard deviation), and limits of agreement (mean±2 standard deviations) of the angle between five anatomically defined tibial reference lines used in mechanically aligned (MA) TKA and the F-E tibial reference line (+external). The following are the bias, imprecision, and limits of agreement of the angle between the F-E tibial reference line and 1) the tibial reference lines connecting the medial border (-2°±6°, -14° to 10°), medial 1/3 (6°±6°, -6° to 18°), and the most anterior point of the tibial tubercle (9°±4°, -1° to 17°) with the center of the posterior cruciate ligament, and 2) the tibial reference lines perpendicular to the posterior condylar axis of the tibia (-3°±4°, -11° to 5°), and a line connecting the centers of the tibial condyles (1°±4°, -7° to 9°). Based on these in vitro findings, it might be prudent to reconsider setting the I-E rotation of the tibial component to tibial reference lines that have bias, imprecision, and limits of agreement that fall outside the -7° to 10° range associated with high function after KA TKA. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Quantitative comparison of the microscopic anatomy of the human ACL femoral and tibial entheses.

    PubMed

    Beaulieu, Mélanie L; Carey, Grace E; Schlecht, Stephen H; Wojtys, Edward M; Ashton-Miller, James A

    2015-12-01

    The femoral enthesis of the human anterior cruciate ligament (ACL) is known to be more susceptible to injury than the tibial enthesis. To determine whether anatomic differences might help explain this difference, we quantified the microscopic appearance of both entheses in 15 unembalmed knee specimens using light microscopy, toluidine blue stain and image analysis. The amount of calcified fibrocartilage and uncalcified fibrocartilage, and the ligament entheseal attachment angle were then compared between the femoral and tibial entheses via linear mixed-effects models. The results showed marked differences in anatomy between the two entheses. The femoral enthesis exhibited a 3.9-fold more acute ligament attachment angle than the tibial enthesis (p<0.001), a 43% greater calcified fibrocartilage tissue area (p<0.001), and a 226% greater uncalcified fibrocartilage depth (p<0.001), with the latter differences being particularly pronounced in the central region. We conclude that the ACL femoral enthesis has more fibrocartilage and a more acute ligament attachment angle than the tibial enthesis, which provides insight into why it is more vulnerable to failure. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  13. Severe lateral tibial bowing with short stature in two siblings--a provisionally novel syndrome.

    PubMed

    Zitano, Lia; Loder, Randall T; Cohen, Mervyn D; Weaver, David D

    2012-09-01

    In this report, we describe two siblings with short stature and severe lateral tibial bowing. In the younger sibling, the bowing was bilateral, while in the older sib, it was unilateral. However, both showed bilateral abnormalities of the distal tibial epiphyses and growth plates. Pseudoarthrosis of the left distal tibial metaphysis and subsequent spontaneous resolution of the abnormality occurred in the younger sibling. The fibulas of both children were of normal diameter and were straight, except for the distal ends. Surgery has almost completely corrected the lower leg bowing in both patients. The type of tibial bowing seen in these children can be associated with a number of syndromes, such as neurofibromatosis type I, Weismann-Netter syndrome, and a variety of environmental caused disorders, such as vitamin D deficient rickets. However, the severity of the bowing present in our patients and the absence of other clinical features differentiates this condition from those reported in the literature. We posit that the condition in the children presented here represents an as yet undescribed syndrome, which is likely to be of genetic origin. Copyright © 2012 Wiley Periodicals, Inc.

  14. "Clothesline technique" for proximal tibial shaft fracture fixation using conventional intramedullary nail: a simple, useful, and inexpensive technique to prevent fracture malalignment.

    PubMed

    Belangero, William Dias; Santos Pires, Robinson Esteves; Livani, Bruno; Rossi, Felipe Lins; de Andrade, Andre Luis Lugnani

    2018-05-01

    Treatment of proximal tibial shaft fractures is always challenging. Despite the development of modern techniques, the literature still shows high complication rates, especially regarding proximal fragment malalignment. It is well known that knee position in flexion during tibial nailing is responsible for extension and valgus deformities of the proximal fragment. Unlike in tibial shaft fractures, nails do not reduce proximal tibial fractures due to the medullary canal width. This study aims to describe a simple, useful, and inexpensive technique to prevent valgus and extension deformities when treating proximal tibial fractures using conventional nails: the so-called clothesline technique.

  15. Tibial nerve stimulation to inhibit the micturition reflex by an implantable wireless driver microstimulator in cats

    PubMed Central

    Li, Xing; Liao, Li-Min; Chen, Guo-Qing; Wang, Zhao-Xia; Lu, Tian-Ji; Deng, Han; Loeb, Gerald-E

    2016-01-01

    Abstract Background: Traditional tibial nerve stimulation (TNS) has been used to treat overactive bladder syndrome (OAB), but there are some shortcomings. Thus, a novel alternative is needed for the treatment of OAB. The study investigated the effects of a new type of tibial nerve microstimulator on the micturition reflex in cats. Methods: An implantable wireless driver microstimulator was implanted around the tibial nerve in 9 α-chloralose anesthetized cats. Cystometry was performed by infusing 0.9% normal saline (NS) or 0.25% acetic acid (AA) through a urethral catheter. Multiple cystometrograms were performed before, during, and after TNS to determine the inhibitory effect of the microstimulator on the micturition reflex. Results: TNS at 2 threshold (T) intensity significantly increased the bladder capacity (BC) during NS infusion. Bladder overactivity was irritated by the intravesical infusion of 0.25% AA, which significantly reduced the BC compared with the NS infusion. TNS at 2 T intensity suppressed AA-induced bladder overactivity and significantly increased the BC compared with the AA control. Conclusion: The implantable wireless driver tibial nerve microstimulator appears to be effective in inhibiting the micturition reflex during physiologic and pathologic conditions. The implantable wireless driver tibial nerve microstimulator could be used to treat OAB. PMID:27537576

  16. Do running speed and shoe cushioning influence impact loading and tibial shock in basketball players?

    PubMed Central

    Liebenberg, Jacobus; Woo, Jeonghyun; Park, Sang-Kyoon; Yoon, Suk-Hoon; Cheung, Roy Tsz-Hei; Ryu, Jiseon

    2018-01-01

    Background Tibial stress fracture (TSF) is a common injury in basketball players. This condition has been associated with high tibial shock and impact loading, which can be affected by running speed, footwear condition, and footstrike pattern. However, these relationships were established in runners but not in basketball players, with very little research done on impact loading and speed. Hence, this study compared tibial shock, impact loading, and foot strike pattern in basketball players running at different speeds with different shoe cushioning properties/performances. Methods Eighteen male collegiate basketball players performed straight running trials with different shoe cushioning (regular-, better-, and best-cushioning) and running speed conditions (3.0 m/s vs. 6.0 m/s) on a flat instrumented runway. Tri-axial accelerometer, force plate and motion capture system were used to determine tibial accelerations, vertical ground reaction forces and footstrike patterns in each condition, respectively. Comfort perception was indicated on a 150 mm Visual Analogue Scale. A 2 (speed) × 3 (footwear) repeated measures ANOVA was used to examine the main effects of shoe cushioning and running speeds. Results Greater tibial shock (P < 0.001; η2 = 0.80) and impact loading (P < 0.001; η2 = 0.73–0.87) were experienced at faster running speeds. Interestingly, shoes with regular-cushioning or best-cushioning resulted in greater tibial shock (P = 0.03; η2 = 0.39) and impact loading (P = 0.03; η2 = 0.38–0.68) than shoes with better-cushioning. Basketball players continued using a rearfoot strike during running, regardless of running speed and footwear cushioning conditions (P > 0.14; η2 = 0.13). Discussion There may be an optimal band of shoe cushioning for better protection against TSF. These findings may provide insights to formulate rehabilitation protocols for basketball players who are recovering from TSF. PMID:29770274

  17. [High tibial osteotomy--fixation by means of external fixation--indication, technique, complications (author's transl)].

    PubMed

    Klems, H

    1976-02-01

    High tibial osteotomy has proved its value in the treatment of gonarthrosis with or without axis deformity. The thrust of weight-bearing and other stresses is lessened on the degenerated tibial condyle and transferred to the more normal condyle. The stable fixation by means of external fixation allows early movement of the knee joint.-R-ferences to operative technique, indication, complications and after-treatment.

  18. Comparison of fixed-bearing and mobile-bearing total knee arthroplasty after high tibial osteotomy.

    PubMed

    Hernigou, Philippe; Huys, Maxime; Pariat, Jacques; Roubineau, François; Flouzat Lachaniette, Charles Henri; Dubory, Arnaud

    2018-02-01

    There is no information comparing the results of fixed-bearing total knee replacement and mobile-bearing total knee replacement in the same patients previously treated by high tibial osteotomy. The purpose was therefore to compare fixed-bearing and mobile-bearing total knee replacements in patients treated with previous high tibial osteotomy. We compared the results of 57 patients with osteoarthritis who had received a fixed-bearing prosthesis after high tibial osteotomy with the results of 41 matched patients who had received a rotating platform after high tibial osteotomy. The match was made for length of follow-up period. The mean follow-up was 17 years (range, 15-20 years). The patients were assessed clinically and radiographically. The pre-operative knee scores had no statistically significant differences between the two groups. So was the case with the intra-operative releases, blood loss, thromboembolic complications and infection rates in either group. There was significant improvement in both groups of knees, and no significant difference was observed between the groups (i.e., fixed-bearing and mobile-bearing knees) for the mean Knee Society knee clinical score (95 and 92 points, respectively), or the Knee Society knee functional score (82 and 83 points, respectively) at the latest follow-up. However, the mean post-operative knee motion was higher for the fixed-bearing group (117° versus 110°). In the fixed-bearing group, one knee was revised because of periprosthetic fracture. In the rotating platform mobile-bearing group, one knee was revised because of aseptic loosening of the tibial component. The Kaplan-Meier survivorship for revision at ten years of follow-up was 95.2% for the fixed bearing prosthesis and 91.1% for the rotating platform mobile-bearing prosthesis. Although we did manage to detect significant differences mainly in clinical and radiographic results between the two groups, we found no superiority or inferiority of the mobile

  19. Ultra high molecular weight polyethylene (UHMWPE) fiber epoxy composite hybridized with Gadolinium and Boron nanoparticles for radiation shielding

    NASA Astrophysics Data System (ADS)

    Mani, Venkat; Prasad, Narasimha S.; Kelkar, Ajit

    2016-09-01

    Deep space radiations pose a major threat to the astronauts and their spacecraft during long duration space exploration missions. The two sources of radiation that are of concern are the galactic cosmic radiation (GCR) and the short lived secondary neutron radiations that are generated as a result of fragmentation that occurs when GCR strikes target nuclei in a spacecraft. Energy loss, during the interaction of GCR and the shielding material, increases with the charge to mass ratio of the shielding material. Hydrogen with no neutron in its nucleus has the highest charge to mass ratio and is the element which is the most effective shield against GCR. Some of the polymers because of their higher hydrogen content also serve as radiation shield materials. Ultra High Molecular Weight Polyethylene (UHMWPE) fibers, apart from possessing radiation shielding properties by the virtue of the high hydrogen content, are known for extraordinary properties. An effective radiation shielding material is the one that will offer protection from GCR and impede the secondary neutron radiations resulting from the fragmentation process. Neutrons, which result from fragmentation, do not respond to the Coulombic interaction that shield against GCR. To prevent the deleterious effects of secondary neutrons, targets such as Gadolinium are required. In this paper, the radiation shielding studies that were carried out on the fabricated sandwich panels by vacuum-assisted resin transfer molding (VARTM) process are presented. VARTM is a manufacturing process used for making large composite structures by infusing resin into base materials formed with woven fabric or fiber using vacuum pressure. Using the VARTM process, the hybridization of Epoxy/UHMWPE composites with Gadolinium nanoparticles, Boron, and Boron carbide nanoparticles in the form of sandwich panels were successfully carried out. The preliminary results from neutron radiation tests show that greater than 99% shielding performance was

  20. Do Tibial Plateau Fractures Worsen Outcomes of Knee Ligament Injuries? A Matched Cohort Analysis

    PubMed Central

    Cinque, Mark E.; Godin, Jonathan A.; Moatshe, Gilbert; Chahla, Jorge; Kruckeberg, Bradley M.; Pogorzelski, Jonas; LaPrade, Robert F.

    2017-01-01

    Background: Tibial plateau fractures account for a small portion of all fractures; however, these fractures can pose a surgical challenge when occurring concomitantly with ligament injuries. Purpose/Hypothesis: The purpose of this study was to compare 2-year outcomes of soft tissue reconstruction with or without a concomitant tibial plateau fracture and open reduction internal fixation. We hypothesized that patients with a concomitant tibial plateau fracture at the time of soft tissue surgery would have inferior outcomes compared with patients without an associated tibial plateau fracture. Study Design: Cohort study; Level of evidence, 3. Methods: Forty patients were included in this study: 8 in the fracture group and 32 in the matched control group. Inclusion criteria for the fracture group included patients who were at least 18 years old at the time of surgery and sustained a tibial plateau fracture and a concomitant injury of the anterior cruciate ligament, posterior cruciate ligament, medial collateral ligament, or fibular collateral ligament in isolation or any combination of cruciate or collateral ligaments and who subsequently underwent isolated or combined ligament reconstruction. Patients were excluded if they underwent prior ipsilateral knee surgery, sustained additional bony injuries, or sustained an isolated extra-articular ligament injury at the time of injury. Each patient with a fracture was matched with 4 patients from a control group who had no evidence of a tibial plateau fracture but underwent the same soft tissue reconstruction procedure. Results: Patients in the fracture group improved significantly from preoperatively to postoperatively with respect to Short Form–12 (P < .05) and Western Ontario and McMaster Universities Osteoarthritis Index total scores (P < .05). The Lysholm (P = .075) and Tegner scores (P = .086) also improved, although this was not statistically significant. Patients in the control group improved significantly from

  1. Achilles lengthening/posterior tibial tenotomy with immediate weightbearing for patients with significant comorbidities.

    PubMed

    Redfern, John C; Thordarson, David B

    2008-03-01

    Fixed equinovarus deformities can be challenging to treat especially in medically debilitated patients. The purpose of this study was to evaluate Achilles lengthening with posterior tibial tenotomy and immediate weightbearing in this difficult group of patients. Thirteen extremities in 10 patients underwent Achilles lengthening and posterior tibial tenotomy for fixed equinovarus deformities with significant medical comorbidities. Pre- and postoperative ambulatory status and deformities were noted. Average age at the time of surgery was 65 with an average duration of deformity 6.3 years. The average equinus corrected from 26 degrees to 1.2 degrees and the average varus deformity improved from -8.5 degrees to 2.7 degrees. All patients except one who was wheelchair-bound had a significant improvement in ambulatory status. Achilles lengthening with posterior tibial tenotomy allowed for immediate postoperative weightbearing with improvement in deformity and ambulatory status in this complicated patient group.

  2. Chronic exertional compartment syndrome with medial tibial stress syndrome in twins.

    PubMed

    Banerjee, Purnajyoti; McLean, Christopher

    2011-06-14

    Chronic exertional compartment syndrome and medial tibial stress syndrome are uncommon conditions that affect long-distance runners or players involved in team sports that require extensive running. We report 2 cases of bilateral chronic exertional compartment syndrome, with medial tibial stress syndrome in identical twins diagnosed with the use of a Kodiag monitor (B. Braun Medical, Sheffield, United Kingdom) fulfilling the modified diagnostic criteria for chronic exertional compartment syndrome as described by Pedowitz et al, which includes: (1) pre-exercise compartment pressure level >15 mm Hg; (2) 1 minute post-exercise pressure >30 mm Hg; and (3) 5 minutes post-exercise pressure >20 mm Hg in the presence of clinical features. Both patients were treated with bilateral anterior fasciotomies through minimal incision and deep posterior fasciotomies with tibial periosteal stripping performed through longer anteromedial incisions under direct vision followed by intensive physiotherapy resulting in complete symptomatic recovery. The etiology of chronic exertional compartment syndrome is not fully understood, but it is postulated abnormal increases in intramuscular pressure during exercise impair local perfusion, causing ischemic muscle pain. No familial predisposition has been reported to date. However, some authors have found that no significant difference exists in the relative perfusion, in patients, diagnosed with chronic exertional compartment syndrome. Magnetic resonance images of affected compartments have indicated that the pain is not due to ischemia, but rather from a disproportionate oxygen supply versus demand. We believe this is the first report of chronic exertional compartment syndrome with medial tibial stress syndrome in twins, raising the question of whether there is a genetic predisposition to the causation of these conditions. Copyright 2011, SLACK Incorporated.

  3. Total knee arthroplasty in patients with a prior fracture of the tibial plateau.

    PubMed

    Weiss, Nicholas G; Parvizi, Javad; Trousdale, Robert T; Bryce, Rex D; Lewallen, David G

    2003-02-01

    A fracture of the tibial plateau may predispose the knee to the development of posttraumatic arthritis. Malunion, intra-articular chondro-osseous defects, limb malalignment, retained internal fixation devices, and poor surrounding soft tissues may in turn compromise the outcome of total knee arthroplasty. The aim of our study was to evaluate the results of total knee arthroplasty in patients with a previous fracture of the tibial plateau. The results of sixty-two condylar total knee arthroplasties performed with cement, from 1988 to 1999, in sixty-two patients with a previous fracture of the tibial plateau were reviewed. The fracture of the tibial plateau had been treated by open reduction and internal fixation in thirty-eight knees, external fixation in one knee, and nonoperatively in twenty-three knees. There were forty women and twenty-two men with an average age of sixty-three years at the time of the arthroplasty. Knee Society scores were recorded preoperatively and at the time of follow-up, at an average of 4.7 years, and complications were noted. No patient was lost to follow-up. The mean Knee Society scores improved significantly (p < 0.0001), from 43.9 points for pain and 52 points for function preoperatively to 82.9 and 84 points, respectively, at the time of the latest follow-up. There were thirteen reoperations, which included manipulation with the patient under anesthesia (five knees), wound revision (three knees), and component revision (five knees). There were six intraoperative complications (10%). A postoperative complication occurred in sixteen knees (26%). The vast majority of patients treated with total knee arthroplasty after a previous fracture of the tibial plateau have substantial improvement in function and relief of pain. However, these patients are at increased risk for perioperative complications, as evidenced by the high reoperation rate of 21% in this study.

  4. Assessment of tibial rotation and meniscal movement using kinematic magnetic resonance imaging

    PubMed Central

    2014-01-01

    Objective This work aimed to assess tibial rotations, meniscal movements, and morphological changes during knee flexion and extension using kinematic magnetic resonance imaging (MRI). Methods Thirty volunteers with healthy knees were examined using kinematic MRI. The knees were imaged in the transverse plane with flexion and extension angles from 0° to 40° and 40° to 0°, respectively. The tibial interior and exterior rotation angles were measured, and the meniscal movement range, height change, and side movements were detected. Results The tibia rotated internally (11.55° ± 3.20°) during knee flexion and rotated externally (11.40° ± 3.0°) during knee extension. No significant differences were observed between the internal and external tibial rotation angles (P > 0.05), between males and females (P > 0.05), or between the left and right knee joints (P > 0.05). The tibial rotation angle with a flexion angle of 0° to 24° differed significantly from that with a flexion angle of 24° to 40° (P < 0.01). With knee flexion, the medial and lateral menisci moved backward and the height of the meniscus increased. The movement range was greater in the anterior horn than in the posterior horn and greater in the lateral meniscus than in the medial meniscus (P < 0.01). During backward movements of the menisci, the distance between the anterior and posterior horns decreased, with the decrease more apparent in the lateral meniscus (P < 0.01). The side movements of the medial and lateral menisci were not obvious, and a smaller movement range was found than that of the forward and backward movements. Conclusion Knee flexion and extension facilitated internal and external tibial rotations, which may be related to the ligament and joint capsule structure and femoral condyle geometry. PMID:25142267

  5. The Impact of Computed Tomography on Decision Making in Tibial Plateau Fractures.

    PubMed

    Castiglia, Marcello Teixeira; Nogueira-Barbosa, Marcello Henrique; Messias, Andre Marcio Vieira; Salim, Rodrigo; Fogagnolo, Fabricio; Schatzker, Joseph; Kfuri, Mauricio

    2018-02-14

    Schatzker introduced one of the most used classification systems for tibial plateau fractures, based on plain radiographs. Computed tomography brought to attention the importance of coronal plane-oriented fractures. The goal of our study was to determine if the addition of computed tomography would affect the decision making of surgeons who usually use the Schatzker classification to assess tibial plateau fractures. Image studies of 70 patients who sustained tibial plateau fractures were uploaded to a dedicated homepage. Every patient was linked to a folder which contained two radiographic projections (anteroposterior and lateral), three interactive videos of computed tomography (axial, sagittal, and coronal), and eight pictures depicting tridimensional reconstructions of the tibial plateau. Ten attending orthopaedic surgeons, who were blinded to the cases, were granted access to the homepage and assessed each set of images in two different rounds, separated to each other by an interval of 2 weeks. Each case was evaluated in three steps, where surgeons had access, respectively to radiographs, two-dimensional videos of computed tomography, and three-dimensional reconstruction images. After every step, surgeons were asked to present how would they classify the case using the Schatzker system and which surgical approaches would be appropriate. We evaluated the inter- and intraobserver reliability of the Schatzker classification using the Kappa concordance coefficient, as well as the impact of computed tomography in the decision making regarding the surgical approach for each case, by using the chi-square test and likelihood ratio. The interobserver concordance kappa coefficients after each assessment step were, respectively, 0.58, 0.62, and 0.64. For the intraobserver analysis, the coefficients were, respectively, 0.76, 0.75, and 0.78. Computed tomography changed the surgical approach selection for the types II, V, and VI of Schatzker ( p  < 0.01). The addition of

  6. Tibial slope correction combined with second revision ACL produces good knee stability and prevents graft rupture.

    PubMed

    Dejour, David; Saffarini, Mo; Demey, Guillaume; Baverel, Laurent

    2015-10-01

    Revision ACL reconstruction requires careful analysis of failure causes particularly in cases of two previous graft ruptures. Intrinsic factors as excessive tibial slope or narrow femoral notch increase failure risks but are rarely addressed in revision surgery. The authors report outcomes, at minimum follow-up of 2 years, for second revision ACL reconstructions combined with tibial deflexion osteotomy for correction of excessive slope (>12°). Nine patients that underwent second revision ACL reconstruction combined with tibial deflexion osteotomy were retrospectively studied. The mean age was 30.3 ± 4.4 years (median 28; range 26-37), and mean follow-up was 4.0 ± 2.0 years (median 3.6; range 2.0-7.6). Autografts were harvested from the quadriceps tendon (n = 8) or hamstrings (n = 1), and tibial osteotomy was done by anterior closing wedge, without detachment of the patellar tendon, to obtain a slope of 3° to 5°. All patients had fused osteotomies, stable knees, and there were no intraoperative or postoperative complications. The mean posterior tibial slope decreased from 13.2° ± 2.6° (median 13°; range 12°-18°) preoperatively to 4.4° ± 2.3° (median 4°; range 2°-8°) postoperatively. The mean Lysholm score was 73.8 ± 5.8 (median 74; range 65-82), and the IKDC-SKF was 71.6 ± 6.1 (median 72.8; range 62.2-78.5). The satisfactory results of second revision ACL reconstruction combined with tibial deflexion osteotomy at minimum follow-up of 2 years suggest that tibia slope correction protects reconstructed ACL from fatigue failure in this study. The authors stress the importance of careful analysis failure causes prior to revision ACL reconstruction, and recommend correction of tibial slope if it exceeds 12°, to reduce the risks of graft retear. III.

  7. Location of the tibial tunnel aperture affects extrusion of the lateral meniscus following reconstruction of the anterior cruciate ligament.

    PubMed

    Kodama, Yuya; Furumatsu, Takayuki; Miyazawa, Shinichi; Fujii, Masataka; Tanaka, Takaaki; Inoue, Hiroto; Ozaki, Toshifumi

    2017-08-01

    The anterior root of the lateral meniscus provides functional stability to the meniscus. In this study, we evaluated the relationship between the position of the tibial tunnel and extrusion of the lateral meniscus after anterior cruciate ligament reconstruction, where extrusion provides a proxy measure of injury to the anterior root. The relationship between extrusion and tibial tunnel location was retrospectively evaluated from computed tomography and magnetic resonance images of 26 reconstructed knees, contributed by 25 patients aged 17-31 years. A measurement grid was used to localize the position of the tibial tunnel based on anatomical landmarks identified from the three-dimensional reconstruction of axial computed tomography images of the tibial plateaus. The reference point-to-tibial tunnel distance (mm) was defined as the distance from the midpoint of the lateral edge of the grid to the posterolateral aspect of the tunnel aperture. The optimal cutoff of this distance to minimize post-operative extrusion was identified using receiver operating curve analysis. Extrusion of the lateral meniscus was positively correlated to the reference point-to-tibial tunnel distance (r 2  = 0.64; p < 0.001), with a cutoff distance of 5 mm having a sensitivity to extrusion of 83% and specificity of 93%. The mean extrusion for a distance >5 mm was 0.40 ± 0.43 mm, compared to 1.40 ± 0.51 mm for a distance ≤5 mm (p < 0.001). Therefore, a posterolateral location of the tibial tunnel aperture within the footprint of the anterior cruciate ligament decreases the reference point-to-tibial tunnel distance and increases extrusion of the lateral meniscus post-reconstruction. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1625-1633, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  8. Posterior tibial slope and femoral sizing affect posterior cruciate ligament tension in posterior cruciate-retaining total knee arthroplasty.

    PubMed

    Kuriyama, Shinichi; Ishikawa, Masahiro; Nakamura, Shinichiro; Furu, Moritoshi; Ito, Hiromu; Matsuda, Shuichi

    2015-08-01

    During cruciate-retaining total knee arthroplasty, surgeons sometimes encounter increased tension of the posterior cruciate ligament. This study investigated the effects of femoral size, posterior tibial slope, and rotational alignment of the femoral and tibial components on forces at the posterior cruciate ligament in cruciate-retaining total knee arthroplasty using a musculoskeletal computer simulation. Forces at the posterior cruciate ligament were assessed with the standard femoral component, as well as with 2-mm upsizing and 2-mm downsizing in the anterior-posterior dimension. These forces were also determined with posterior tibial slope angles of 5°, 7°, and 9°, and lastly, were measured in 5° increments when the femoral (tibial) components were positioned from 5° (15°) of internal rotation to 5° (15°) of external rotation. Forces at the posterior cruciate ligament increased by up to 718N with the standard procedure during squatting. The 2-mm downsizing of the femoral component decreased the force at the posterior cruciate ligament by up to 47%. The 2° increment in posterior tibial slope decreased the force at the posterior cruciate ligament by up to 41%. In addition, posterior cruciate ligament tension increased by 11% during internal rotation of the femoral component, and increased by 18% during external rotation of the tibial component. These findings suggest that accurate sizing and bone preparation are very important to maintain posterior cruciate ligament forces in cruciate-retaining total knee arthroplasty. Care should also be taken regarding malrotation of the femoral and tibial components because this increases posterior cruciate ligament tension. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Posterior Tibial Slope Angle Correlates With Peak Sagittal and Frontal Plane Knee Joint Loading During Robotic Simulations of Athletic Tasks.

    PubMed

    Bates, Nathaniel A; Nesbitt, Rebecca J; Shearn, Jason T; Myer, Gregory D; Hewett, Timothy E

    2016-07-01

    Tibial slope angle is a nonmodifiable risk factor for anterior cruciate ligament (ACL) injury. However, the mechanical role of varying tibial slopes during athletic tasks has yet to be clinically quantified. To examine the influence of posterior tibial slope on knee joint loading during controlled, in vitro simulation of the knee joint articulations during athletic tasks. Descriptive laboratory study. A 6 degree of freedom robotic manipulator positionally maneuvered cadaveric knee joints from 12 unique specimens with varying tibial slopes (range, -7.7° to 7.7°) through drop vertical jump and sidestep cutting tasks that were derived from 3-dimensional in vivo motion recordings. Internal knee joint torques and forces were recorded throughout simulation and were linearly correlated with tibial slope. The mean (±SD) posterior tibial slope angle was 2.2° ± 4.3° in the lateral compartment and 2.3° ± 3.3° in the medial compartment. For simulated drop vertical jumps, lateral compartment tibial slope angle expressed moderate, direct correlations with peak internally generated knee adduction (r = 0.60-0.65), flexion (r = 0.64-0.66), lateral (r = 0.57-0.69), and external rotation torques (r = 0.47-0.72) as well as inverse correlations with peak abduction (r = -0.42 to -0.61) and internal rotation torques (r = -0.39 to -0.79). Only frontal plane torques were correlated during sidestep cutting simulations. For simulated drop vertical jumps, medial compartment tibial slope angle expressed moderate, direct correlations with peak internally generated knee flexion torque (r = 0.64-0.69) and lateral knee force (r = 0.55-0.74) as well as inverse correlations with peak external torque (r = -0.34 to -0.67) and medial knee force (r = -0.58 to -0.59). These moderate correlations were also present during simulated sidestep cutting. The investigation supported the theory that increased posterior tibial slope would lead to greater magnitude knee joint moments, specifically

  10. Investigation of the Influence of Shapes-Texture on Surface Deformation of UHMWPE as a Bearing Material in Static Normal Load and Rolling Contact

    NASA Astrophysics Data System (ADS)

    Lestari, W. D.; Ismail, R.; Jamari, J.; Bayuseno, A. P.

    2017-05-01

    Surface texture is a common method for improving wear properties of a tribo-pair of soft and hard bearing material. The reduction of wear rates on the contacting surface material is becoming important issues. In the present study, analysis of the contact pressure on the flat surface of UHMWPE (Ultra High Molecular Weight Polyethylene) under the static- and rolling motion with the surface of steel ball used the 3D finite element method (FEM) (the ABAQUS software version 6.12). Five shaped-texture models (square, circle, ellipse, triangle, and chevron) were presented on the flat surface for analysis. The normal load of 17, 30 and 50 N was deliberately set-up for static and rolling contact analysis. The contact pressure was determined to predict the wear behavior of the shaped-texture on the flat surface of UHMWPE. The results have shown that the static normal load yielded the lowest von-Mises stress distribution on the shaped-texture of the ellipse for all values applied a load, while the square shape experienced the highest stress distribution. Under rolling contact, however, the increasing load yielded the increasing von Mises stress distribution for the texture with a triangle shape. Moreover, the texture shapes for circle, ellipse, and chevron respectively, may undergo the lowest stress distribution for all load. The wear calculation provided that the circle and square shape may undergo the highest wear rates. Obviously, the surface texture of circle, ellipse, and chevron may experience the lowest wear rates and is potential for use in the surface engineering of bearing materials.

  11. Arthroscopic pullout repair of a complete radial tear of the tibial attachment site of the medial meniscus posterior horn.

    PubMed

    Kim, Young-Mo; Rhee, Kwang-Jin; Lee, June-Kyu; Hwang, Deuk-Soo; Yang, Jun-Young; Kim, Sung-Jae

    2006-07-01

    We developed an effective arthroscopic pullout technique for repairing complete radial tears of the tibial attachment site of the medial meniscus posterior horn (MMPH). In our technique, the torn meniscus is reattached to the tibial plateau immediately medial or anteromedial to the posterior cruciate ligament (PCL) using two No. 2 Ethibond sutures (Ethicon, Somerville, NJ). After a complete radial tear of the tibial attachment site of the MMPH and its reparability were confirmed, using a Caspari suture loaded with a suture shuttle, one No. 2 Ethibond suture is placed through the meniscus, through the red-red zone, 3 to 5 mm medial to the torn edge of the MMPH, and the other is passed through the meniscocapsular junction 3 to 5 mm medial to the torn edge of the meniscus. Then, a tibial tunnel, 5-mm in diameter, is made from the anteromedial aspect of the proximal tibia to the previously prepared tibial plateau, immediately medial or anteromedial to the PCL, and the two No. 2 Ethibond sutures are pulled out through the tibial tunnel and then fixed to the proximal tibia using a 3.5-mm cortical screw and washer. Firm reattachment of the torn meniscus was confirmed arthroscopically.

  12. Total Knee Arthroplasty for Osteoarthritis Secondary to Fracture of the Tibial Plateau. A Prospective Matched Cohort Study.

    PubMed

    Lizaur-Utrilla, Alejandro; Collados-Maestre, Isabel; Miralles-Muñoz, Francisco A; Lopez-Prats, Fernando A

    2015-08-01

    A prospective matched cohort study was performed to compare outcomes of total knee arthroplasties (TKA) between 29 patients with posttraumatic osteoarthritis (POA) after a fracture of tibial plateau and 58 patients underwent routine TKA. Mean follow-up was 6.7 years. There were no significant differences in KSS, WOMAC, SF12 scores or range of motion. In the control group there were no complications. In the posttraumatic group, complications occurred in 4 patients (13.7%) (P=0.010) including partial patellar tendon detachment, superficial infection, skin necrosis, and knee stiffness. Only this last patient required revision for manipulation under anesthesia. Also, there was a revision for tibial aseptic loosening in each group. TKA is an effective treatment for POA after tibial plateau fracture. We recommend the prior removal of hardware, as well as tibial tubercle osteotomy when necessary. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Influence of knee flexion and atraumatic mobilisation of infrapatellar fat pad on incidence and severity of anterior knee pain after tibial nailing.

    PubMed

    Jankovic, Andrija; Korac, Zelimir; Bozic, Nenad-Bozo; Stedul, Ivan

    2013-09-01

    We evaluated the incidence and aetiology of anterior knee pain (AKP) in a series of patients that underwent intramedullary nailing for stabilisation of tibial fractures. During the preparation of the entry site no excision of the infrapatellar fat was allowed and electrical haemostasis was kept at the lowest level. Medullary canal was reamed and the nails inserted in position of knee flexion over 100 degrees. All fractures were fixed using medial paratendinous approach. Functional outcome was measured using Lysholm knee score. The knee range of movement and return to previous level of activity were also documented and analysed. Mean follow up was 38.9 months (range 12-84 months). In total 60 patients with 62 tibial shaft fractures were analysed. The mean age at the time of final follow up was 49.4 years (range 20-87). In 22 (35.5%) a newly developed and persisting pain in the anterior region of the operated knee was reported. According to VAP scale, the pain was mild (VAS 1-3) in 12 cases (19.4%) and moderate (VAS 4-6) in 10 (16.1%). In 16 cases (73%) the pain was noticed 6-12 months after injury and subjectively related to return to full range of working and recreational activities. The mean Lysholm knee score in the group without AKP was 90.8. In the AKP group with mild pain it was 88.4 and in the group with moderate AKP it was 79.9. Complete return to previous professional and recreational activities occurred in 49/60 patients (81.7%). Content with the treatment regarding expectations in recovery dynamics and return to desired level of activity was present in 98.3% of patients; one patient was unsatisfied with the treatment. Our results indicate that respecting the physiological motion of Hoffa pad and menisci during knee flexion, accompanied with atraumatic mobilisation of retrotendinous fat, reduces incidence and severity of anterior knee pain following intramedullary fixation of tibial shaft fractures. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. The use of a robotic tibial rotation device and an electromagnetic tracking system to accurately reproduce the clinical dial test.

    PubMed

    Stinton, S K; Siebold, R; Freedberg, H; Jacobs, C; Branch, T P

    2016-03-01

    The purpose of this study was to: (1) determine whether a robotic tibial rotation device and an electromagnetic tracking system could accurately reproduce the clinical dial test at 30° of knee flexion; (2) compare rotation data captured at the footplates of the robotic device to tibial rotation data measured using an electromagnetic sensor on the proximal tibia. Thirty-two unilateral ACL-reconstructed patients were examined using a robotic tibial rotation device that mimicked the dial test. The data reported in this study is only from the healthy legs of these patients. Torque was applied through footplates and was measured using servomotors. Lower leg motion was measured at the foot using the motors. Tibial motion was also measured through an electromagnetic tracking system and a sensor on the proximal tibia. Load-deformation curves representing rotational motion of the foot and tibia were compared using Pearson's correlation coefficients. Off-axis motions including medial-lateral translation and anterior-posterior translation were also measured using the electromagnetic system. The robotic device and electromagnetic system were able to provide axial rotation data and translational data for the tibia during the dial test. Motion measured at the foot was not correlated to motion of the tibial tubercle in internal rotation or in external rotation. The position of the tibial tubercle was 26.9° ± 11.6° more internally rotated than the foot at torque 0 Nm. Medial-lateral translation and anterior-posterior translation were combined to show the path of the tubercle in the coronal plane during tibial rotation. The information captured during a manual dial test includes both rotation of the tibia and proximal tibia translation. All of this information can be captured using a robotic tibial axial rotation device with an electromagnetic tracking system. The pathway of the tibial tubercle during tibial axial rotation can provide additional information about knee

  15. Radiologic assessment of femoral and tibial tunnel placement based on anatomic landmarks in arthroscopic single bundle anterior cruciate ligament reconstruction.

    PubMed

    Nema, Sandeep Kumar; Balaji, Gopisankar; Akkilagunta, Sujiv; Menon, Jagdish; Poduval, Murali; Patro, Dilip

    2017-01-01

    Accurate tibial and femoral tunnel placement has a significant effect on outcomes after anterior cruciate ligament reconstruction (ACLR). Postoperative radiographs provide a reliable and valid way for the assessment of anatomical tunnel placement after ACLR. The aim of this study was to examine the radiographic location of tibial and femoral tunnels in patients who underwent arthroscopic ACLR using anatomic landmarks. Patients who underwent arthroscopic ACLR from January 2014 to March 2016 were included in this retrospective cohort study. 45 patients who underwent arthroscopic ACLR, postoperative radiographs were studied. Femoral and tibial tunnel positions on sagittal and coronal radiographic views, graft impingement, and femoral roof angle were measured. Radiological parameters were summarized as mean ± standard deviation and proportions as applicable. Interobserver agreement was measured using intraclass correlation coefficient. The position of the tibial tunnel was found to be at an average of 35.1% ± 7.4% posterior from the anterior edge of the tibia. The femoral tunnel was found at an average of 30% ± 1% anterior to the posterior femoral cortex along the Blumensaat's line. Radiographic impingement was found in 34% of the patients. The roof angle averaged 34.3° ± 4.3°. The position of the tibial tunnel was found at an average of 44.16% ± 3.98% from the medial edge of the tibial plateau. The coronal tibial tunnel angle averaged 67.5° ± 8.9°. The coronal angle of the femoral tunnel averaged 41.9° ± 8.5°. The femoral and tibial tunnel placements correlated well with anatomic landmarks except for radiographic impingement which was present in 34% of the patients.

  16. Soft tissue graft interference fit fixation: observations on graft insertion site healing and tunnel remodeling 2 years after ACL reconstruction in sheep.

    PubMed

    Hunt, Patrick; Rehm, Oliver; Weiler, Andreas

    2006-12-01

    Using soft tissue grafts for anterior cruciate ligament (ACL) reconstruction, insertion site healing plays a crucial role in the long-term fate of the graft. It has been shown in an experimental animal study that using a soft tissue graft and anatomic graft fixation, a direct ligamentous insertion alike the native ACL developed 24 weeks postoperatively. Yet there are no reports on the long-term insertion site healing of anatomically fixed soft tissue grafts. The objective of this study was to evaluate graft insertion site healing, the intra-tunnel fate of the graft and its osseous replacement 2 years after ACL reconstruction in sheep. The left ACLs of six sheep were replaced by an autologous flexor tendon split graft and anatomically fixed with biodegradable poly-(D, L-lactide) interference screws. Animals received polychromic sequential labeling at different points in time to determine bone apposition per period. For evaluation of the insertion site healing and intra-tunnel changes, MRI scans were taken in vivo. Following sacrifice, radiographic imaging, conventional histology and fluorescence microscopy was undertaken. Most of the specimens showed a wide direct ligamentous insertion. It showed patterns alike the direct ligament insertion seen in intact ACLs. The intra-tunnel part of the graft had completely lost its tendon-like structure and in two cases, it was separated from the graft insertion by a thick bony layer. The biodegradable interference screw was fully degraded in all specimens. Ossification of the former drill tunnels was intense, showing only partial-length tunnel remnants in one femoral and three tibial specimens. As the graft heals to the joint surface and the aperture site is closed with soft tissue, mechanical stress of the intra-tunnel part of the graft is eliminated and the bone tunnel is protected from synovial fluid, resulting in osseous bridging of the tunnel aperture site, accelerated intra-tunnel graft resorption and its osseous

  17. High-resolution axial MR imaging of tibial stress injuries

    PubMed Central

    2012-01-01

    Purpose To evaluate the relative involvement of tibial stress injuries using high-resolution axial MR imaging and the correlation with MR and radiographic images. Methods A total of 33 patients with exercise-induced tibial pain were evaluated. All patients underwent radiograph and high-resolution axial MR imaging. Radiographs were taken at initial presentation and 4 weeks later. High-resolution MR axial images were obtained using a microscopy surface coil with 60 × 60 mm field of view on a 1.5T MR unit. All images were evaluated for abnormal signals of the periosteum, cortex and bone marrow. Results Nineteen patients showed no periosteal reaction at initial and follow-up radiographs. MR imaging showed abnormal signals in the periosteal tissue and partially abnormal signals in the bone marrow. In 7 patients, periosteal reaction was not seen at initial radiograph, but was detected at follow-up radiograph. MR imaging showed abnormal signals in the periosteal tissue and entire bone marrow. Abnormal signals in the cortex were found in 6 patients. The remaining 7 showed periosteal reactions at initial radiograph. MR imaging showed abnormal signals in the periosteal tissue in 6 patients. Abnormal signals were seen in the partial and entire bone marrow in 4 and 3 patients, respectively. Conclusions Bone marrow abnormalities in high-resolution axial MR imaging were related to periosteal reactions at follow-up radiograph. Bone marrow abnormalities might predict later periosteal reactions, suggesting shin splints or stress fractures. High-resolution axial MR imaging is useful in early discrimination of tibial stress injuries. PMID:22574840

  18. Role of the fibula in the stability of diaphyseal tibial fractures fixed by intramedullary nailing.

    PubMed

    Galbraith, John G; Daly, Charles J; Harty, James A; Dailey, Hannah L

    2016-10-01

    For tibial fractures, the decision to fix a concomitant fibular fracture is undertaken on a case-by-case basis. To aid in this clinical decision-making process, we investigated whether loss of integrity of the fibula significantly destabilises midshaft tibial fractures, whether fixation of the fibula restores stability to the tibia, and whether removal of the fibula and interosseous membrane for expediency in biomechanical testing significantly influences tibial interfragmentary mechanics. Tibia/fibula pairs were harvested from six cadaveric donors with the interosseous membrane intact. A tibial osteotomy fracture was fixed by reamed intramedullary (IM) nailing. Axial, torsion, bending, and shear tests were completed for four models of fibular involvement: intact fibula, osteotomy fracture, fibular plating, and resected fibula and interosseous membrane. Overall construct stiffness decreased slightly with fibular osteotomy compared to intact bone, but this change was not statistically significant. Under low loads, the influence of the fibula on construct stability was only statistically significant in torsion (large effect size). Fibular plating stiffened the construct slightly, but this change was not statistically significant compared to the fibular osteotomy case. Complete resection of the fibula and interosseous membrane significantly decreased construct torsional stiffness only (large effect size). These results suggest that fixation of the fibula may not contribute significantly to the stability of diaphyseal tibial fractures and should not be undertaken unless otherwise clinically indicated. For testing purposes, load-sharing through the interosseous membrane contributes significantly to overall construct mechanics, especially in torsion, and we recommend preservation of these structures when possible. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Management of Open Tibial Shaft Fractures: Does the Timing of Surgery Affect Outcomes?

    PubMed

    Duyos, Oscar A; Beaton-Comulada, David; Davila-Parrilla, Ariel; Perez-Lopez, Jose Carlos; Ortiz, Krystal; Foy-Parrilla, Christian; Lopez-Gonzalez, Francisco

    2017-03-01

    Open tibial shaft fractures require emergent care. Treatment with intravenous antibiotics and fracture débridement within 6 to 24 hours is recommended. Few studies have examined outcomes when surgical treatment is performed >24 hours after occurrence of the fracture. This retrospective study included 227 patients aged ≥18 years with isolated open tibial shaft fractures in whom the time to initial débridement was >24 hours. The statistical analysis was based on time from injury to surgical débridement, Gustilo-Anderson classification, method of fixation, union status, and infection status. Fractures débrided within 24 to 48 hours and 48 to 96 hours after injury did not show a statistically significant difference in terms of infection rates (P = 0.984). External fixation showed significantly greater infection rates (P = 0.044) and nonunion rates (P = 0.001) compared with intramedullary nailing. Open tibial shaft fractures should be débrided within 24 hours after injury. Our data indicate that after the 24-hour period and up to 4 days, the risk of infection remains relatively constant independent of the time to débridement. Patients treated with external fixation had more complications than did patients treated with other methods of fixation. Primary reamed intramedullary nailing appears to be a reasonable option for the management of Gustilo-Anderson types 1 and 2 open tibial shaft fractures. Level III retrospective study.

  20. Tibial lengthening using a humeral intramedullary nail combined with a single-plane external fixator for leg discrepancy in sequelae of poliomyelitis.

    PubMed

    Chen, Daoyun; Chen, Jianmin; Liu, Fanggang; Jiang, Yao

    2011-03-01

    The sequelae of poliomyelitis are the common causes of leg discrepancy. Tibial lengthening is an effective way to solve this problem but it is associated with a high rate of complications. In this study, we combined the use of humeral nail and external fixator in tibial lengthening with the purpose of reducing lengthening complications. Compared with the cases lengthened by a single-plane external fixator alone, this combined strategy was found to be beneficial in maintaining the tibial alignment. Therefore, it can be recommended as a good technique for tibial lengthening in patients with sequelae of poliomyelitis.

  1. A Biomechanical Study of Posteromedial Tibial Plateau Fracture Stability: Do They All Require Fixation?

    PubMed

    Cuéllar, Vanessa G; Martinez, Danny; Immerman, Igor; Oh, Cheongeun; Walker, Peter S; Egol, Kenneth A

    2015-07-01

    Although the posteromedial fragment in tibial plateau fractures is often considered unstable, biomechanical evidence supporting this view is lacking. We aimed to evaluate the stability of the fragment in a cadaver model. Our hypothesis was that under the expected small axial force during rehabilitation and the combined effects of this force with shear force, internal rotation torque, and varus moment, the most common posteromedial tibial fragment morphology could maintain stability in early flexion. Axial compression force alone or combined with posterior shear, internal rotation torque, or varus moment was applied to the femurs of 5 fresh cadaveric knees. A Tekscan pressure mapping system was used to measure pressure and contact area between the femoral condyles, meniscus, and tibial plateau. A Microscribe 3D digitizer was used to define the 3-dimensional positions of the femur and tibia. A 10-mm and then a 20-mm osteotomy was created with a saw at an angle of 30 degrees in the axial plane with respect to the tangent of the posterior tibial plateau and 75 degrees in the sagittal plane, representing a typical posteromedial fracture fragment. At each flexion angle (15, 30, 60, 90, and 120 degrees) and loading condition (axial compression only, compression with shear force, torque, and varus moment), distal displacement of the medial femoral condyle and the tibial fracture fragments was determined. For the 10-mm fragment, medial femoral condyle displacement was little affected up to approximately 30-degree flexion, after which it increased. For the 20-mm fragment, there was progressive medial femoral condyle displacement with increasing flexion from baseline. However, for the 10- and 20-mm fragments themselves, displacements were noted at every flexion angle, starting at 1.7 mm inferior displacement with 15 degrees of flexion and internal rotation torque and up to 10.2 mm displacement with 90 degrees of flexion and varus bending moment. In this cadaveric model of a

  2. An investigation of the inelastic behaviour of trabecular bone during the press-fit implantation of a tibial component in total knee arthroplasty.

    PubMed

    Kelly, N; Cawley, D T; Shannon, F J; McGarry, J P

    2013-11-01

    The stress distribution and plastic deformation of peri-prosthetic trabecular bone during press-fit tibial component implantation in total knee arthroplasty is investigated using experimental and finite element techniques. It is revealed that the computed stress distribution, implantation force and plastic deformation in the trabecular bone is highly dependent on the plasticity formulation implemented. By incorporating pressure dependent yielding using a crushable foam plasticity formulation to simulate the trabecular bone during implantation, highly localised stress concentrations and plastic deformation are computed at the bone-implant interface. If the pressure dependent yield is neglected using a traditional von Mises plasticity formulation, a significantly different stress distribution and implantation force is computed in the peri-prosthetic trabecular bone. The results of the study highlight the importance of: (i) simulating the insertion process of press-fit stem implantation; (ii) implementing a pressure dependent plasticity formulation, such as the crushable foam plasticity formulation, for the trabecular bone; (iii) incorporating friction at the implant-bone interface during stem insertion. Simulation of the press-fit implantation process with an appropriate pressure dependent plasticity formulation should be implemented in the design and assessment of arthroplasty prostheses. Copyright © 2013 IPEM. Published by Elsevier Ltd. All rights reserved.

  3. Radiologic assessment of femoral and tibial tunnel placement based on anatomic landmarks in arthroscopic single bundle anterior cruciate ligament reconstruction

    PubMed Central

    Nema, Sandeep Kumar; Balaji, Gopisankar; Akkilagunta, Sujiv; Menon, Jagdish; Poduval, Murali; Patro, Dilip

    2017-01-01

    Background: Accurate tibial and femoral tunnel placement has a significant effect on outcomes after anterior cruciate ligament reconstruction (ACLR). Postoperative radiographs provide a reliable and valid way for the assessment of anatomical tunnel placement after ACLR. The aim of this study was to examine the radiographic location of tibial and femoral tunnels in patients who underwent arthroscopic ACLR using anatomic landmarks. Patients who underwent arthroscopic ACLR from January 2014 to March 2016 were included in this retrospective cohort study. Materials and Methods: 45 patients who underwent arthroscopic ACLR, postoperative radiographs were studied. Femoral and tibial tunnel positions on sagittal and coronal radiographic views, graft impingement, and femoral roof angle were measured. Radiological parameters were summarized as mean ± standard deviation and proportions as applicable. Interobserver agreement was measured using intraclass correlation coefficient. Results: The position of the tibial tunnel was found to be at an average of 35.1% ± 7.4% posterior from the anterior edge of the tibia. The femoral tunnel was found at an average of 30% ± 1% anterior to the posterior femoral cortex along the Blumensaat's line. Radiographic impingement was found in 34% of the patients. The roof angle averaged 34.3° ± 4.3°. The position of the tibial tunnel was found at an average of 44.16% ± 3.98% from the medial edge of the tibial plateau. The coronal tibial tunnel angle averaged 67.5° ± 8.9°. The coronal angle of the femoral tunnel averaged 41.9° ± 8.5°. Conclusions: The femoral and tibial tunnel placements correlated well with anatomic landmarks except for radiographic impingement which was present in 34% of the patients. PMID:28566780

  4. The effect of proximal tibial slope on dynamic stability testing of the posterior cruciate ligament- and posterolateral corner-deficient knee.

    PubMed

    Petrigliano, Frank A; Suero, Eduardo M; Voos, James E; Pearle, Andrew D; Allen, Answorth A

    2012-06-01

    Proximal tibial slope has been shown to influence anteroposterior translation and tibial resting point in the posterior cruciate ligament (PCL)-deficient knee. The effect of proximal tibial slope on rotational stability of the knee is unknown. Change in proximal tibial slope produced via osteotomy can influence both static translation and dynamic rotational kinematics in the PCL/posterolateral corner (PLC)-deficient knee. Controlled laboratory study. Posterior drawer, dial, and mechanized reverse pivot-shift (RPS) tests were performed on hip-to-toe specimens and translation of the lateral and medial compartments measured utilizing navigation (n = 10). The PCL and structures of the PLC were then sectioned. Stability testing was repeated, and compartmental translation was recorded. A proximal tibial osteotomy in the sagittal plane was then performed achieving either +5° or -5° of tibial slope variation, after which stability testing was repeated (n = 10). Analysis was performed using 1-way analysis of variance (ANOVA; α = .05). Combined sectioning of the PCL and PLC structures resulted in a 10.5-mm increase in the posterior drawer, 15.5-mm increase in the dial test at 30°, 14.5-mm increase in the dial test at 90°, and 17.9-mm increase in the RPS (vs intact; P < .05). Increasing the posterior slope (high tibial osteotomy [HTO] +5°) in the PCL/PLC-deficient knee reduced medial compartment translation by 3.3 mm during posterior drawer (vs deficient; P < .05) but had no significant effect on the dial test at 30°, dial test at 90°, or RPS. Conversely, reversing the slope (HTO -5°) caused a 4.8-mm increase in medial compartment translation (vs deficient state; P < .05) during posterior drawer and an 8.6-mm increase in lateral compartment translation and 9.0-mm increase in medial compartment translation during RPS (vs deficient state; P < .05). Increasing posterior tibial slope diminished static posterior instability of the PCL/PLC-deficient knee as measured by the

  5. Locking plate fixation in distal metaphyseal tibial fractures: series of 79 patients.

    PubMed

    Gupta, Rakesh K; Rohilla, Rajesh Kumar; Sangwan, Kapil; Singh, Vijendra; Walia, Saurav

    2010-12-01

    Open reduction and internal fixation in distal tibial fractures jeopardises fracture fragment vascularity and often results in soft tissue complications. Minimally invasive osteosynthesis, if possible, offers the best possible option as it permits adequate fixation in a biological manner. Seventy-nine consecutive adult patients with distal tibial fractures, including one patient with a bilateral fracture of the distal tibia, treated with locking plates, were retrospectively reviewed. The 4.5-mm limited-contact locking compression plate (LC-LCP) was used in 33 fractures, the metaphyseal LCP in 27 fractures and the distal medial tibial LCP in the remaining 20 fractures. Fibula fixation was performed in the majority of comminuted fractures (n = 41) to maintain the second column of the ankle so as to achieve indirect reduction and to prevent collapse of the fracture. There were two cases of delayed wound breakdown in fractures fixed with the 4.5-mm LC-LCP. Five patients required primary bone grafting and three patients required secondary bone grafting. All cases of delayed union (n = 7) and nonunion (n = 3) were observed in cases where plates were used in bridge mode. Minimally invasive plate osteosynthesis (MIPO) with LCP was observed to be a reliable method of stabilisation for these fractures. Peri-operative docking of fracture ends may be a good option in severely impacted fractures with gap. The precontoured distal medial tibial LCP was observed to be a better tolerated implant in comparison to the 4.5-mm LC-LCP or metaphyseal LCP with respect to complications of soft tissues, bone healing and functional outcome, though its contour needs to be modified.

  6. Open-wedge high tibial osteotomy: comparison between manual and computer-assisted techniques.

    PubMed

    Iorio, R; Pagnottelli, M; Vadalà, A; Giannetti, S; Di Sette, P; Papandrea, P; Conteduca, F; Ferretti, A

    2013-01-01

    The purpose of our study was to compare clinical and radiological results of two groups of patients treated for medial compartment osteoarthritis of the knee with either conventional or computer-assisted open-wedge high tibial osteotomy (HTO). Goals of surgical treatment were a correction of the mechanical axis between 2° and 6° of valgus and a modification of posterior tibial slope between -2° and +2°. Twenty-four patients (27 knees) affected by varus knee deformity and operated with HTO were prospectively followed-up. They were randomly divided in two groups, A (11 patients, conventional treatment) and B (13 patients, navigated treatment). The American Knee Society Score and the Modified Cincinnati Rating System Questionnaire were used for clinical assessment. All patients were radiologically evaluated with a comparative lower limb weight-bearing digital radiograph, a standard digital anteroposterior, a latero-lateral radiograph of the knee, and a Rosenberg view. Patients were followed-up at a mean of 39 months. Clinical evaluation showed no statistical difference (n.s.) between the two groups. Radiological results showed an 86% reproducibility in achieving a mechanical axis of 182°-186° in group B compared to a 23% in group A (p = 0.0392); furthermore, in group B, we achieved a modification of posterior tibial slope between -2° and +2° in 100% of patients, while in group A, this goal was achieved only in 24% of cases (p = 0.0021). High tibial osteotomy with navigator is more accurate and reproducible in the correction of the deformity compared to standard technique. Therapeutic study, Level II.

  7. Oxidised zirconium versus cobalt alloy bearing surfaces in total knee arthroplasty: 3D laser scanning of retrieved polyethylene inserts.

    PubMed

    Anderson, F L; Koch, C N; Elpers, M E; Wright, T M; Haas, S B; Heyse, T J

    2017-06-01

    We sought to establish whether an oxidised zirconium (OxZr) femoral component causes less loss of polyethylene volume than a cobalt alloy (CoCr) femoral component in total knee arthroplasty. A total of 20 retrieved tibial inserts that had articulated with OxZr components were matched with 20 inserts from CoCr articulations for patient age, body mass index, length of implantation, and revision diagnosis. Changes in dimensions of the articular surfaces were compared with those of pristine inserts using laser scanning. The differences in volume between the retrieved and pristine surfaces of the two groups were calculated and compared. The loss of polyethylene volume was 122 mm 3 (standard deviation (sd) 87) in the OxZr group and 170 mm 3 (sd 96) in the CoCr group (p = 0.033). The volume loss in the OxZr group was also lower in the medial (72 mm 3 (sd 67) versus 92 mm 3 (sd 60); p = 0.096) and lateral (49 mm 3 (sd 36) versus 79 mm 3 (sd 61); p = 0.096) compartments separately, but these differences were not significant. Our results corroborate earlier findings from in vitro testing and visual retrieval analysis which suggest that polyethylene volume loss is lower with OxZr femoral components. Since both OxZr and CoCr are hard surfaces that would be expected to create comparable amounts of polyethylene creep, the differences in volume loss may reflect differences in the in vivo wear of these inserts. Cite this article: Bone Joint J 2017;99-B:793-8. ©2017 The British Editorial Society of Bone & Joint Surgery.

  8. Fixator-assisted medial tibial plateau elevation to treat severe Blount's disease: outcomes at maturity.

    PubMed

    Fitoussi, F; Ilharreborde, B; Lefevre, Y; Souchet, P; Presedo, A; Mazda, K; Penneçot, G F

    2011-04-01

    Severe forms of Blount's disease may be associated with medial tibial plateau (MTP) depression. Management should then take account of joint congruence, laxity, limb axis, torsional abnomality, leg length discrepancy (LLD) and eventual recurrence history. Eight knees (six patients) were managed in a single step comprising MTP elevation osteotomy, lateral epiphysiodesis and proximal tibia osteotomy to correct varus and rotational deformity. Fixation was achieved using an Ilizarov external fixator. Mean age was 10.5 years. Mean hip-knee-ankle (HKA) angle was 151°; distal femoral varus, 94°; metaphyseal-diaphyseal angle (MDA), 27°; and angle of depression of the medial tibial plateau (ADMTP), 42°. Predicted residual proximal tibial growth was 2.6 cm. At a mean 48 months' follow-up, results were good in six cases, medium in one and poor (due to incomplete lateral epiphysiodesis) in one. Mean lateral tibial torsion was 9° and final LLD 11 mm. Weight-bearing was resumed at 2 months, and the fixator was removed at 5.5 months postoperatively. At end of follow-up, mean HKA angle was 179.6°, MDA 7.3° and ADMTP 5.4°. This technically demanding procedure gave satisfactory results in terms of axes and congruence; longer term assessment remains needed. Level IV. Retrospective study. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  9. Combined chemical and mechanical effects on free radicals in UHMWPE joints during implantation.

    PubMed

    Jahan, M S; Wang, C; Schwartz, G; Davidson, J A

    1991-08-01

    An electron spin resonance (ESR) technique is employed to determine the free radical distribution in the articulating surfaces of retrieved acetabular cups and knee-joint plateaus (retrieved after more than 6 years of implantation). Similar measurements made on samples prepared from cyclically stressed and unstressed cups, and on samples following oxidations in nitric acid and intralipid solutions provided sufficient data to gain more knowledge about the combined chemical and mechanical effects on PE free radicals during implantation. In UHMWPE free radicals are primarily initiated by gamma-ray sterilization; however, during implantation, peroxy (scission type) free radicals are formed and reach a maximum concentration level (equilibrium state) due to oxidation by chemical (hemoglobin and/or synovial fluids) environment of the joints. Subsequently, due to frictional heating and stress in the loading zones, free radical reaction is accelerated and their number is reduced only in those areas. This is consistent with the observations of a temperature rise in acetabular cups during in vitro frictional wear stress tests and in vivo telemetry observations, as reported by others. Compared with the previously reported SEM micrographs the low-free-radical regions are correlated with high-wear areas and the high-free-radical regions with the low-wear areas.

  10. Surgical treatment of a proximal diaphyseal tibial deformity associated with partial caudal and cranial cruciate ligament deficiency and patella baja.

    PubMed

    Vincenti, S; Knell, S; Pozzi, A

    2017-04-01

    Caudal cruciate ligament injury can be a complication following tibial plateau leveling osteotomy (TPLO) (Slocum und Slocum, 1993) especially if the post-operative Tibial Plateau Angle (TPA) is less than 5 degree. We describe a case of negative TPA associated with partial cranial and caudal ligament rupture treated with a center of rotation of angulation (CORA) based cranial tibial opening wedge osteotomy and tibial tuberosity transposition. A 13 kg, mixed breed dog was presented for right pelvic limb lameness. Radiographically a bilateral patella baja and a malformed tibia tuberosity along with a bilateral TPA of -8 degree were detected. Arthroscopically a partial rupture of the cranial and caudal cruciate ligaments were found. A cranial tibial opening wedge osteotomy of 23 degree and a fibular ostectomy were performed. The osteotomy was fixed with a 8 holes ALPS 9 (KYON, Switzerland) and a 3-holes 2.0mm UniLock plate (Synthes, Switzerland). Then a proximal tibial tuberosity transposition of 10mm was performed and fixed with a pin and tension band construct. The postoperative TPA was 15 degree. The radiographic controls at 6, 10 weeks, 6 months and 1 year after surgery revealed an unchanged position of the implants and progressive healing of the osteotomies. At the 6 and 12 months recheck evaluation the dog had no evidence of lameness or stifle pain and radiographs revealed complete healing of the osteotomy site and no implant failure. The diaphyseal CORA based osteotomy allowed accurate correction of a proximal tibial deformity associated with negative TPA.

  11. Lateralization of the Tibial Tubercle in Recurrent Patellar Dislocation: Verification Using Multiple Methods to Evaluate the Tibial Tubercle.

    PubMed

    Tensho, Keiji; Shimodaira, Hiroki; Akaoka, Yusuke; Koyama, Suguru; Hatanaka, Daisuke; Ikegami, Shota; Kato, Hiroyuki; Saito, Naoto

    2018-05-02

    The tibial tubercle deviation associated with recurrent patellar dislocation (RPD) has not been studied sufficiently. New methods of evaluation were used to verify the extent of tubercle deviation in a group with patellar dislocation compared with that in a control group, the frequency of patients who demonstrated a cutoff value indicating that tubercle transfer was warranted on the basis of the control group distribution, and the validity of these methods of evaluation for diagnosing RPD. Sixty-six patients with a history of patellar dislocation (single in 19 [SPD group] and recurrent in 47 [RPD group]) and 66 age and sex-matched controls were analyzed with the use of computed tomography (CT). The tibial tubercle-posterior cruciate ligament (TT-PCL) distance, TT-PCL ratio, and tibial tubercle lateralization (TTL) in the SPD and RPD groups were compared with those in the control group. Cutoff values to warrant 10 mm of transfer were based on either the minimum or -2SD (2 standard deviations below the mean) value in the control group, and the prevalences of patients in the RPD group with measurements above these cutoff values were calculated. The area under the curve (AUC) in receiver operating characteristic (ROC) curve analysis was used to assess the effectiveness of the measurements as predictors of RPD. The mean TT-PCL distance, TT-PCL ratio, and TTL were all significantly greater in the RPD group than in the control group. The numbers of patients in the RPD group who satisfied the cutoff criteria when they were based on the minimum TT-PCL distance, TT-PCL ratio, and TTL in the control group were 11 (23%), 7 (15%), and 6 (13%), respectively. When the cutoff values were based on the -2SD values in the control group, the numbers of patients were 8 (17%), 6 (13%), and 0, respectively. The AUC of the ROC curve for TT-PCL distance, TT-PCL ratio, and TTL was 0.66, 0.72, and 0.72, respectively. The extent of TTL in the RPD group was not substantial, and the percentages

  12. Biomechanical analysis of four different fixations for the posterolateral shearing tibial plateau fracture.

    PubMed

    Zhang, Wei; Luo, Cong-Feng; Putnis, Sven; Sun, Hui; Zeng, Zhi-Min; Zeng, Bing-Fang

    2012-03-01

    The posterolateral shearing tibial plateau fracture is uncommon in the literature, however with the increased usage of computer tomography (CT), the incidence of these fractures is no longer as low as previously thought. Few studies have concentrated on this fracture, least of all using a biomechanical model. The purpose of this study was to compare and analyse the biomechanical characteristics of four different types of internal fixation to stabilise the posterolateral shearing tibial plateau fracture. Forty synthetic tibiae (Synbone, right) simulated the posterolateral shearing fracture models and these were randomly assigned into four groups; Group A was fixed with two anterolateral lag screws, Group B with an anteromedial Limited Contact Dynamic Compression Plate (LC-DCP), Group C with a lateral locking plate, and Group D with a posterolateral buttress plate. Vertical displacement of the posterolateral fragment was measured using three different strengths of axial loading force, and finally loaded until fixation failure. It was concluded that the posterolateral buttress plate is biomechanically the strongest fixation method for the posterolateral shearing tibial plateau fracture. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. Improvement of the knee center of rotation during walking after opening wedge high tibial osteotomy.

    PubMed

    Kim, Kyungsoo; Feng, Jun; Nha, Kyung Wook; Park, Won Man; Kim, Yoon Hyuk

    2015-06-01

    Accurate measurement of the center of rotation of the knee joint is indispensable for prediction of joint kinematics and kinetics in musculoskeletal models. However, no study has yet identified the knee center of rotations during several daily activities before and after high tibial osteotomy surgery, which is one surgical option for treating knee osteoarthritis. In this study, an estimation method for determining the knee joint center of rotation was developed by applying the optimal common shape technique and symmetrical axis of rotation approach techniques to motion-capture data and validated for typical activities (walking, squatting, climbing up stairs, walking down stairs) of 10 normal subjects. The locations of knee joint center of rotations for injured and contralateral knees of eight subjects with osteoarthritis, both before and after high tibial osteotomy surgery, were then calculated during walking. It was shown that high tibial osteotomy surgery improved the knee joint center of rotation since the center of rotations for the injured knee after high tibial osteotomy surgery were significantly closer to those of the normal healthy population. The difference between the injured and contralateral knees was also generally reduced after surgery, demonstrating increased symmetry. These results indicate that symmetry in both knees can be recovered in many cases after high tibial osteotomy surgery. Moreover, the recovery of center of rotation in the injured knee was prior to that of symmetry. This study has the potential to provide fundamental information that can be applied to understand abnormal kinematics in patients, diagnose knee joint disease, and design a novel implants for knee joint surgeries. © IMechE 2015.

  14. Arthroscopic evaluation of soft tissue injuries in tibial plateau fractures: retrospective analysis of 98 cases.

    PubMed

    Abdel-Hamid, Mohamed Zaki; Chang, Chung-Hsun; Chan, Yi-Sheng; Lo, Yang-Pin; Huang, Jau-Wen; Hsu, Kuo-Yao; Wang, Ching-Jen

    2006-06-01

    This investigation arthroscopically assesses the frequency of soft tissue injury in tibial plateau fracture according to the severity of fracture patterns. We hypothesized that use of arthroscopy to evaluate soft tissue injury in tibial plateau fractures would reveal a greater number of associated injuries than have previously been reported. From March 1996 to December 2003, 98 patients with closed tibial plateau fractures were treated with arthroscopically assisted reduction and osteosynthesis, with precise diagnosis and management of associated soft tissue injuries. Arthroscopic findings for associated soft tissue injuries were recorded, and the relationship between fracture type and soft tissue injury was then analyzed. The frequency of associated soft tissue injury in this series was 71% (70 of 98). The menisci were injured in 57% of subjects (56 in 98), the anterior cruciate ligament (ACL) in 25% (24 of 98), the posterior cruciate ligament (PCL) in 5% (5 of 98), the lateral collateral ligament (LCL) in 3% (3 of 98), the medial collateral ligament (MCL) in 3% (3 of 98), and the peroneal nerve in 1% (1 of 98); none of the 98 patients exhibited injury to the arteries. No significant association was noted between fracture type and incidence of meniscus, PCL, LCL, MCL, artery, and nerve injury. However, significantly higher injury rates for the ACL were observed in type IV and VI fractures. Soft tissue injury was associated with all types of tibial plateau fracture. Menisci (peripheral tear) and ACL (bony avulsion) were the most commonly injured sites. A variety of soft tissue injuries are common with tibial plateau fracture; these can be diagnosed with the use of an arthroscope. Level III, diagnostic study.

  15. Long-term anabolic effects of prostaglandin-E2 on tibial diaphyseal bone in male rats

    NASA Technical Reports Server (NTRS)

    Jee, Webster S. S.; Ke, Hua Zhu; Li, Xiao Jian

    1991-01-01

    The effects of long-term prostaglandin E2 (PGE2) on tibial diaphyseal bone were studied in 7-month-old male Sprague-Dawley rats given daily subcutaneous injections of 0, 1, 3 and 6 mg PGE2/kg/day for 60, 120 and 180 days. The tibial shaft was measured by single photon absorptiometry and dynamic histomorphometric analyses were performed on double-fluorescent labeled undecalcified tibial diaphyseal bone samples. Exogenous PGE2 administration produced the following transient changes in a dose-response manner between zero and 60 days: (1) increased bone width and mineral density; (2) increased total tissue and total bone areas; (3) decreased marrow area; (4) increased periosteal and corticoendosteal lamellar bone formation; (5) activated corticoendosteal lamellar and woven trabecular bone formation; and (6) activated intracortical bone remodeling. A new steady-state of increased tibial diaphyseal bone mass and elevated bone activities were observed from day 60 onward. The elevated bone mass level attained after 60 days of PGE2 treatment was maintained at 120 and 180 days. These observations indicate that the powerful anabolic effects of PGE2 will increase both periosteal and corticoendosteal bone mass and sustain the transient increase in bone mass with continuous daily administration of PGE2.

  16. Cemented tibial component fixation performs better than cementless fixation: a randomized radiostereometric study comparing porous-coated, hydroxyapatite-coated and cemented tibial components over 5 years.

    PubMed

    Carlsson, Ake; Björkman, Anders; Besjakov, Jack; Onsten, Ingemar

    2005-06-01

    The question whether the tibial component of a total knee arthroplasty should be fixed to bone with or without bone cement has not yet been definitely answered. We studied movements between the tibial component and bone by radiostereometry (RSA) in total knee replacement (TKR) for 3 different types of fixation: cemented fixation (C-F), uncemented porous fixation (UC-F) and uncemented porous hydroxyapatite fixation (UCHA-F). 116 patients with osteoarthrosis, who had 146 TKRs, were included in 2 randomized series. The first series included 86 unilateral TKRs stratified into 1 of the 3 types of fixation. The second series included 30 patients who had simultaneous bilateral TKR surgery, and who were stratified into 3 subgroups of pairwise comparisons of the 3 types of fixation. After 5 years 2 knees had been revised, neither of which were due to loosening. 1 UCHA-F knee in the unilateral series showed a large and continuous migration and a poor clinical result, and is a pending failure. The C-F knees rotated and migrated less than UC-F and UCHA-F knees over 5 years. UCHA-F migrated less than UC-F after 1 year. Cementing of the tibial component offers more stable bone-implant contact for 5 years compared to uncemented fixation. When using uncemented components, however, there is evidence that augmenting a porous surface with hydroxyapatite may mean less motion between implant and bone after the initial postoperative year.

  17. The role of the deep medial collateral ligament in controlling rotational stability of the knee.

    PubMed

    Cavaignac, Etienne; Carpentier, Karel; Pailhé, Regis; Luyckx, Thomas; Bellemans, Johan

    2015-10-01

    The tibial insertion of the deep medial collateral ligament (dMCL) is frequently sacrificed when the proximal tibial cut is performed during total knee arthroplasty. The role of the dMCL in controlling the knee's rotational stability is still controversial. The aim of this study was to quantify the rotational laxity induced by an isolated lesion of the dMCL as it occurs during tibial preparation for knee arthroplasty. An isolated resection of the deep MCL was performed in 10 fresh-frozen cadaver knees. Rotational laxity was measured during application of a standard 5.0 N.m rotational torque. Maximal tibial rotation was measured at different knee flexion angles using an image-guided navigation system (Medivision Surgetics system, Praxim, Grenoble, France) before and after dMCL resection. In all cases, internal and external tibial rotation increased after dMCL resection. Total rotational laxity increased significantly for all knee flexion angles, with an average difference of +7.8° (SD 5.7) with the knee in extension, +8.9° (SD 1.9) in 30° flexion, +7° (SD 2.9) in 60° flexion and +5.3° (SD 2.8) in 90° flexion. Sacrificing the tibial insertion of the deep MCL increases rotational laxity of the knee by 5°-9°, depending on the knee flexion angle. Based on our findings, new surgical techniques and implants that preserve the dMCL insertion such as tibial inlay components should be developed. Further clinical evaluations are necessary.

  18. Etiologic factors in the development of medial tibial stress syndrome: a review of the literature.

    PubMed

    Tweed, Jo L; Avil, Steven J; Campbell, Jackie A; Barnes, Mike R

    2008-01-01

    Medial tibial stress syndrome is a type of exercise-induced leg pain that is common in recreational and competitive athletes. Although various studies have attempted to find the exact pathogenesis of this common condition, it remains unknown. Various theories in literature from 1976 to 2006 were reviewed using key words. Until recently, inflammation of the periosteum due to excessive traction was thought to be the most likely cause of medial tibial stress syndrome. This periostitis has been hypothesized by some authors to be caused by the tearing away of the muscle fibers at the muscle-bone interface, although there are several suggestions as to which, if any, muscle is responsible. Recent studies have supported the view that medial tibial stress syndrome is not an inflammatory process of the periosteum but instead a stress reaction of bone that has become painful.

  19. ß-TCP bone substitutes in tibial plateau depression fractures.

    PubMed

    Rolvien, Tim; Barvencik, Florian; Klatte, Till Orla; Busse, Björn; Hahn, Michael; Rueger, Johannes Maria; Rupprecht, Martin

    2017-10-01

    The use of beta-tricalciumphospate (ß-TCP, Cerasorb®) ceramics as an alternative for autologous bone-grafting has been outlined previously, however with no study focusing on both clinical and histological outcomes of ß-TCP application in patients with multi-fragment tibial plateau fractures. The aim of this study was to analyze the long-term results of ß-TCP in patients with tibial plateau fractures. 52 patients were included in this study. All patients underwent open surgery with ß-TCP block or granulate application. After a mean follow-up of 36months (14-64months), the patients were reviewed. Radiography and computed-tomography were performed, while the Rasmussen score was obtained for clinical outcome. Furthermore, seven patients underwent biopsy during hardware removal, which was subsequently analyzed by histology and backscattered electron microscopy (BSEM). An excellent reduction with two millimeters or less of residual incongruity was achieved in 83% of the patients. At follow-up, no further changes occurred and no nonunions were observed. Functional outcome was good to excellent in 82%. Four patients underwent revision surgery due to reasons unrelated to the bone substitute material. Histologic analyses indicated that new bone was built around the ß-TCP-grafts, however a complete resorption of ß-TCP was not observed. ß-TCP combined with internal fixation represents an effective and safe treatment of tibial plateau depression fractures with good functional recovery. While its osteoconductivity seems to be successful, the biological degradation and replacement of ß-TCP is less pronounced in humans than previous animal studies have indicated. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Influence of gamma-irradiation sterilization and temperature on the fracture toughness of ultra-high-molecular-weight polyethylene.

    PubMed

    Pascaud, R S; Evans, W T; McCullagh, P J; FitzPatrick, D P

    1997-05-01

    Surface damage of the tibial plateau components of knee prostheses made from medical grade ultra-high-molecular-weight polyethylene (UHMW-PE) has been attributed to delamination wear caused by a fatigue fracture mechanism. It has been proposed that factors such as component design and method of sterilization contribute to such failure mechanisms. Understanding the fracture behaviour of UHMW-PE is therefore critical in optimizing the in vivo life-span of total joint components. The elastic-plastic fracture toughness parameter J was consequently determined for a commercial UHMW-PE at ambient and body temperatures, before and after gamma-irradiation sterilization in air at a minimum dose of 29 kGy. Both ductile stability theory and experimental data suggest that cracks propagate in a stable manner, although stability is affected by the sterilization process. Sterilization with gamma-irradiation results in a loss in fracture toughness JIc of 50% and a decrease in tearing modulus (Tm) of 30%. This dramatic reduction could result in a 50% decrease in the residual strength of the components, maximum permissible crack size under service loading and service life (assuming flaws such as fusion defects exist). The time required for a crack to grow from its original size to the maximum permissible size could be decreased by 30%, resulting in earlier failure. In terms of the design of joint replacement components the critical factor to envisage is the design stress level, which should be halved to account for the irradiation process. A scanning electron microscope study reveals that the material fails in layers parallel to the fracture surface.

  1. Gamma inert sterilization: a solution to polyethylene oxidation?

    PubMed

    Medel, Francisco J; Kurtz, Steven M; Hozack, William J; Parvizi, Javad; Purtill, James J; Sharkey, Peter F; MacDonald, Daniel; Kraay, Matthew J; Goldberg, Victor; Rimnac, Clare M

    2009-04-01

    In the 1990s, oxidation was found to occur in ultra-high molecular weight polyethylene total joint replacement components following gamma irradiation and prolonged shelf aging in air. Orthopaedic manufacturers developed barrier packaging to reduce oxidation during and after radiation sterilization. The present study explores the hypothesis that polyethylene components sterilized in a low-oxygen environment undergo similar in vivo oxidative mechanisms as inserts sterilized in air. In addition, the potential influence of the different sterilization processes on the wear performance of the polyethylene components was examined. An analysis of oxidation, wear, and surface damage was performed for forty-eight acetabular liners and 123 tibial inserts. The mean implantation time was 12.3+/-3.7 years for thirty-one acetabular liners that had been gamma sterilized in air and 4.0+/-2.5 years for the seventeen acetabular liners that had been gamma sterilized in inert gas. The mean implantation time was 11.0+/-3.2 years for the twenty-six tibial inserts that had been sterilized in air and 2.8+/-2.2 years for the ninety-seven tibial inserts that had been gamma sterilized in inert gas. Oxidation and hydroperoxide levels were characterized in loaded and unloaded regions of the inserts. Measurable oxidation and oxidation potential were observed in all cohorts. The oxidation and hydroperoxide levels were regional. Surfaces with access to body fluids were more heavily oxidized than protected bearing surfaces were. This variation appeared to be greater in historical (gamma-in-air-sterilized) components. Regarding wear performance, historical and conventional acetabular liners showed similar wear penetration rates, whereas a low incidence of delamination was confirmed for the conventional tibial inserts in the first decade of implantation. The present study explores the impact of industry-wide changes in sterilization practices for polyethylene. We found lower oxidation and oxidation

  2. [Effects of posterior tibial slope on non-contact anterior cruciate ligament rupture and stability of anterior cruciate ligament rupture knee].

    PubMed

    Yue, De-bo; E, Sen; Wang, Bai-liang; Wang, Wei-guo; Guo, Wan-shou; Zhang, Qi-dong

    2013-05-07

    To retrospectively explore the correlation between anterior cruciate ligament (ACL)-ruptured knees, stability of ACL-rupture knee and posterior tibial slope (PTS). From January 2008 to October 2012, 150 knees with ACL rupture underwent arthroscopic surgery for ACL reconstruction. A control group was established for subjects undergoing arthroscopic surgery without ACL rupture during the same period. PTS was measured on a digitalized lateral radiograph. Lachman and mechanized pivot shift tests were performed for assessing the stability of knee. There was significant difference (P = 0.007) in PTS angle between the patients with ACL rupture (9.5 ± 2.2 degrees) and the control group (6.6 ± 1.8 degrees). Only among females, increased slope of tibial plateau had effect on the Lachman test. There was a higher positive rate of pivot shift test in patients of increased posterior slope in the ACL rupture group. Increased posterior tibial slope (>6.6) appears to contribute to non-contact ACL injuries in females. And the changes of tibial slope have no effect upon the Lachman test. However, large changes in tibial slope affect pivot shift.

  3. Atypical presentation of popliteal artery entrapment syndrome: involvement of the anterior tibial artery.

    PubMed

    Bou, Steven; Day, Carly

    2014-11-01

    Popliteal artery entrapment syndrome (PAES) is a rare condition that should be suspected in a young patient with exertional lower extremity pain. We report the case of an 18-year-old female volleyball player with bilateral exertional lower extremity pain who had been previously diagnosed with tendinitis and periostitis. Diagnostic studies showed entrapment of the left popliteal artery and the left anterior tibial artery. To our knowledge, there has only been 1 previous report of anterior tibial artery involvement in PAES. Copyright © 2014 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

  4. Forefoot-rearfoot coupling patterns and tibial internal rotation during stance phase of barefoot versus shod running.

    PubMed

    Eslami, Mansour; Begon, Mickaël; Farahpour, Nader; Allard, Paul

    2007-01-01

    Based on twisted plate and mitered hinge models of the foot and ankle, forefoot-rearfoot coupling motion patterns can contribute to the amount of tibial rotation. The present study determined the differences of forefoot-rearfoot coupling patterns as well as excessive excursion of tibial internal rotation in shod versus barefoot conditions during running. Sixteen male subjects ran 10 times at 170 steps per minute under the barefoot and shod conditions. Forefoot-rearfoot coupling motions were assessed by measuring mean relative phase angle during five intervals of stance phase for the main effect of five time intervals and two conditions (ANOVA, P<0.05). Tibial internal rotation excursion was compared between the shod and barefoot conditions over the first 50% of stance phase using paired t-test, (P<0.05). Forefoot adduction/abduction and rearfoot eversion/inversion coupling motion patterns were significantly different between the conditions and among the intervals (P<0.05; effect size=0.47). The mean absolute relative angle was significantly modified to 37 degrees in-phase relationship at the heel-strike of running with shoe wears. No significant differences were noted in the tibial internal rotation excursion between shod and barefoot conditions. Significant variations in the forefoot adduction/abduction and rearfoot eversion/inversion coupling patterns could have little effect on the amount of tibial internal rotation excursion. Yet it remains to be determined whether changes in the frontal plane forefoot-rearfoot coupling patterns influence the tibia kinematics for different shoe wears or foot orthotic interventions. The findings question the rational for the prophylactic use of forefoot posting in foot orthoses.

  5. Incidence of complications associated with tibial tuberosity advancement in Boxer dogs.

    PubMed

    de Lima Dantas, Brigite; Sul, Rui; Parkin, Tim; Calvo, Ignacio

    2016-01-01

    To retrospectively review and describe the incidence of complications associated with tibial tuberosity advancement (TTA) surgical procedures in a group of Boxer dogs (n = 36 stifles) and compare the data with a non-Boxer control population (n = 271 stifles). Retrospective analysis of medical records to identify all dogs that underwent TTA surgery due to cranial cruciate ligament disease. These records were categorized into two groups: Boxer dogs and non-Boxer dogs (controls - all other breeds). Of the 307 stifles included, 69 complications were reported in 58 joints. The complication rate differed significantly for Boxer dogs (16/36 stifles) and non-Boxer dogs (42/271 stifles), corresponding to an odds ratio of 5.8 (confidence interval: 1.96-17.02; p-value <0.001). Boxer dogs were more likely to undergo revision surgery and to develop multiple complications. The incidence of tibial tuberosity fractures requiring surgical repair (2/36 versus 1/271) and incisional infections requiring antibiotic treatment (three in each group) was significantly higher in the Boxer group. Boxer dogs had more major and multiple complications after TTA surgery than the control non-Boxer group; these complications included higher rates of revision surgery, tibial tuberosity fractures requiring stabilization, and infection related complications. The pertinence and value of breed-specific recommendations for cranial cruciate ligament disease appears to be a subject worthy of further investigation.

  6. Os tibiale externum or sesamoid in the tendon of tibialis posterior.

    PubMed

    Bareither, D J; Muehleman, C M; Feldman, N J

    1995-01-01

    From a total of 165 foot and lower leg cadaveric specimens, 38 specimens were selected by palpation of the region of the tuberosity of the navicular for the possible presence of an accessory bone. Specimens were radiographed and dissected to reveal the presence of an accessory bone and its relationship to the tibialis posterior tendon. Nineteen of the specimens exhibited hypertrophy of the tibialis posterior tendon and 19 specimens exhibited an accessory bone. Specimens exhibiting an accessory bone were divided into two categories. In one group, the accessory bone was located in the tibialis posterior tendon prior to its division and was separated from the tuberosity by at least 3 mm. In the other group, the accessory bone was located in the main segment of the tibialis posterior tendon, connected to the tuberosity of the navicular by fibrous tissue, and, in some cases, exhibited a central cavity between the accessory bone and tuberosity. The accessory bone of specimens in the first group was considered to be a sesamoid in the tibialis posterior tendon and the accessory bone in the second group was an ossicle considered to be the os tibiale externum. Linking the os tibiale externum to the tibiale component of the primitive tetrapod foot rather than to the prehallux component eliminates the use of the term "prehallux" as an alternative name for this ossicle.

  7. EMG and tibial shock upon the first attempt at barefoot running.

    PubMed

    Olin, Evan D; Gutierrez, Gregory M

    2013-04-01

    As a potential means to decrease their risk of injury, many runners are transitioning into barefoot running. Habitually shod runners tend to heel-strike (SHS), landing on their heel first, while barefoot runners tend to mid-foot or toe-strike (BTS), landing flat-footed or on the ball of their foot before bringing down the rest of the foot including the heel. This study compared muscle activity, tibial shock, and knee flexion angle in subjects between shod and barefoot conditions. Eighteen habitually SHS recreational runners ran for 3 separate 7-minute trials, including SHS, barefoot heel-strike (BHS), and BTS conditions. EMG, tibial shock, and knee flexion angle were monitored using bipolar surface electrodes, an accelerometer, and an electrogoniometer, respectively. A one-way MANOVA for repeated measures was conducted and several significant changes were noted between SHS and BTS, including significant increases in average EMG of the medial gastrocnemius (p=.05), average and peak tibial shock (p<.01), and the minimum knee flexion angle (p<.01). Based on our data, the initial change in mechanics may have detrimental effects on the runner. While it has been argued that BTS running may ultimately be less injurious, these data indicate that habitually SHS runners who choose to transition into a BTS technique must undertake the process cautiously. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Experimental Attempts for Deep Insertion in Ultrasonically Forced Insertion Process

    NASA Astrophysics Data System (ADS)

    Ono, Satoshi; Aoyagi, Manabu; Tamura, Hideki; Takano, Takehiro

    2011-07-01

    In this paper, we describe two attempts of obtaining deep insertion in an ultrasonically forced insertion (USFI) process. One was to correct the inclination of an inserted rod by passively generated bending vibrations. The inclination causes a partial plastic deformation, which decreases the holding power of processing materials. Two types of horn with grooves for excitation of bending vibrations were examined. The other was to make differences in vibration velocity and the phase of a rod and a metal plate by damping the vibration of a metal plate by using a rubber sheet. As results, the attempts proposed in this study were confirmed to be effective to obtain a deep insertion.

  9. Risk factors for tibial implant malpositioning in total knee arthrosplasty-consecutive series of one thousand, four hundred and seventeen cases.

    PubMed

    Gaillard, Romain; Cerciello, Simone; Lustig, Sebastien; Servien, Elvire; Neyret, Philippe

    2017-04-01

    Total knee arthroplasty (TKA) malalignment may result in pain and limited range of motion. The present study assessed the influence of different surgeon's and patient's related factors on the post-operative tibial tray coronal alignment. The charts and the x-rays of a continuous prospective series of 1417 TKAs operated upon between 1987 and 2015 were retrospectively reviewed. The long-leg AP views were performed at two months post-op and the tibial mechanical angle of the tibial tray was measured. Three groups were defined: varus (≤87° n = 167), valgus (≥93° n = 55) and well alignment (88° to 92° n = 1195). The influence of several pre-operative and peri-operative factors was investigated: surgeon handedness and experience (junior or senior), previous tibial osteotomies, Ahlbäck stage of osteoarthritits, pre-operative alignment, height and weight, age at surgery, approach (medial, lateral or tibial tubercle osteotomy), generation of implants, tray fixation, size of the tray and stem lenght. Univariate then multivariate analysis were performed to find out any correlation. Multivariate analysis showed a strong correlation between varus alignment of the tibial tray and pre-operative varus of the lower limb (p = 0.037), increased BMI (p = 0.016) and operated side opposite to the dominant surgeon's arm (p = 0.006). In a similar way a strong correlation was found between valgus alignment and pre-operative valgus of the limb (p = 0.026). Poor alignment of the tibial tray after TKA was associated with pre-operative malalignment of the lower limb, increased BMI and an index knee which was opposite to surgeon's dominant arm.

  10. Estimates of Tibial Shock Magnitude in Men and Women at the Start and End of a Military Drill Training Program.

    PubMed

    Rice, Hannah M; Saunders, Samantha C; McGuire, Stephen J; O'Leary, Thomas J; Izard, Rachel M

    2018-03-26

    Foot drill is a key component of military training and is characterized by frequent heel stamping, likely resulting in high tibial shock magnitudes. Higher tibial shock during running has previously been associated with risk of lower limb stress fractures, which are prevalent among military populations. Quantification of tibial shock during drill training is, therefore, warranted. This study aimed to provide estimates of tibial shock during military drill in British Army Basic training. The study also aimed to compare values between men and women, and to identify any differences between the first and final sessions of training. Tibial accelerometers were secured on the right medial, distal shank of 10 British Army recruits (n = 5 men; n = 5 women) throughout a scheduled drill training session in week 1 and week 12 of basic military training. Peak positive accelerations, the average magnitude above given thresholds, and the rate at which each threshold was exceeded were quantified. Mean (SD) peak positive acceleration was 20.8 (2.2) g across all sessions, which is considerably higher than values typically observed during high impact physical activity. Magnitudes of tibial shock were higher in men than women, and higher in week 12 compared with week 1 of training. This study provides the first estimates of tibial shock magnitude during military drill training in the field. The high values suggest that military drill is a demanding activity and this should be considered when developing and evaluating military training programs. Further exploration is required to understand the response of the lower limb to military drill training and the etiology of these responses in the development of lower limb stress fractures.

  11. Moore I postero-medial articular tibial fracture in alpine skiers: Surgical management and return to sports activity.

    PubMed

    Morin, Vincent; Pailhé, Régis; Sharma, Akash; Rouchy, René-Christopher; Cognault, Jérémy; Rubens-Duval, Brice; Saragaglia, Dominique

    2016-06-01

    Over the past 10 years, like many authors, we observed an increasing number of Moore I tibial plateau fractures related to alpine skiing for which the surgeon may face difficult choices regarding surgical approach and fixation means. Some authors have recently been suggesting a posterior approach associated to open reduction and osteosynthesis by a buttress plate. But in our knowledge there is no specific study on sports activity recovery after Moore I tibial fractures. The aim of this work was to assess sports activities and clinical outcomes after surgically treated Moore I tibial plateau fractures in an athletic population of skiers. We conducted a prospective case series between 2012 and 2014. This included fifteen patients aged 39.6±7 years whom presented with a Moore I tibial plateau fracture during a skiing accident. 12 cases (80%) presented with an associated tibial spine fracture. Treatment consisted of a standard antero-medial approach, with a medial para patellar arthrotomy to allow direct visualisation of articular reduction and spinal fixation. Two or three 6.5mm long cancellous bone screws were placed antero-posteriorly so as to ensure perfect compression of the fracture site. Radiological and functional results were assessed by an independent observer (Lysholm-Tegner, UCLA, KOOS scores) at the longest follow-up. Mean follow-up was 18.2±6 months (12-28). An immediate postoperative anatomical reduction was achieved in all cases and remained stable in time. At last follow-up Lysholm mean score was 85±14 points (59-100), UCLA score was 7.3±1.6 (4-10) and Tegner score was 4.6±1.3 (3-6). Mean KOOS score was 77±15 (54-97). 87% of patients had resumed their skiing activity and 93% were satisfied or very satisfied from their post-operative surgical outcome. We observed no pseudarthrosis or secondary varus displacement. In our series 87% of patients had resumed back to their sporting activities. Surgical management of Moore I tibial plateau fractures by

  12. Distal tibial pilon fractures (AO/OTA type B, and C) treated with the external skeletal and minimal internal fixation method.

    PubMed

    Milenković, Sasa; Mitković, Milorad; Micić, Ivan; Mladenović, Desimir; Najman, Stevo; Trajanović, Miroslav; Manić, Miodrag; Mitković, Milan

    2013-09-01

    Distal tibial pilon fractures include extra-articular fractures of the tibial metaphysis and the more severe intra-articular tibial pilon fractures. There is no universal method for treating distal tibial pilon fractures. These fractures are treated by means of open reduction, internal fixation (ORIF) and external skeletal fixation. The high rate of soft-tissue complications associated with primary ORIF of pilon fractures led to the use of external skeletal fixation, with limited internal fixation as an alternative technique for definitive management. The aim of this study was to estimate efficacy of distal tibial pilon fratures treatment using the external skeletal and minimal internal fixation method. We presented a series of 31 operated patients with tibial pilon fractures. The patients were operated on using the method of external skeletal fixation with a minimal internal fixation. According to the AO/OTA classification, 17 patients had type B fracture and 14 patients type C fractures. The rigid external skeletal fixation was transformed into a dynamic external skeletal fixation 6 weeks post-surgery. This retrospective study involved 31 patients with tibial pilon fractures, average age 41.81 (from 21 to 60) years. The average follow-up was 21.86 (from 12 to 48) months. The percentage of union was 90.32%, nonunion 3.22% and malunion 6.45%. The mean to fracture union was 14 (range 12-20) weeks. There were 4 (12.19%) infections around the pins of the external skeletal fixator and one (3.22%) deep infections. The ankle joint arthrosis as a late complication appeared in 4 (12.90%) patients. All arthroses appeared in patients who had type C fractures. The final functional results based on the AOFAS score were excellent in 51.61%, good in 32.25%, average in 12.90% and bad in 3.22% of the patients. External skeletal fixation and minimal internal fixation of distal tibial pilon fractures is a good method for treating all types of inta-articular pilon fractures. In

  13. In vivo tibial stiffness is maintained by whole bone morphology and cross-sectional geometry in growing female mice

    PubMed Central

    Main, Russell P.; Lynch, Maureen E.; van der Meulen, Marjolein C.H.

    2010-01-01

    Whole bone morphology, cortical geometry, and tissue material properties modulate skeletal stresses and strains that in turn influence skeletal physiology and remodeling. Understanding how bone stiffness, the relationship between applied load and tissue strain, is regulated by developmental changes in bone structure and tissue material properties is important in implementing biophysical strategies for promoting healthy bone growth and preventing bone loss. The goal of this study was to relate developmental patterns of in vivo whole bone stiffness to whole bone morphology, cross-sectional geometry, and tissue properties using a mouse axial loading model. We measured in vivo tibial stiffness in three age groups (6wks, 10wks, 16wks old) of female C57Bl/6 mice during cyclic tibial compression. Tibial stiffness was then related to cortical geometry, longitudinal bone curvature, and tissue mineral density using microcomputed tomography (microCT). Tibial stiffness and the stresses induced by axial compression were generally maintained from 6 to 16wks of age. Growth-related increases in cortical cross-sectional geometry and longitudinal bone curvature had counteracting effects on induced bone stresses and, therefore, maintained tibial stiffness similarly with growth. Tissue mineral density increased slightly from 6 to 16wks of age, and although the effects of this increase on tibial stiffness were not directly measured, its role in the modulation of whole bone stiffness was likely minor over the age range examined. Thus, whole bone morphology, as characterized by longitudinal curvature, along with cortical geometry, plays an important role in modulating bone stiffness during development and should be considered when evaluating and designing in vivo loading studies and biophysical skeletal therapies. PMID:20673665

  14. Open Tibial Inlay PCL Reconstruction: Surgical Technique and Clinical Outcomes.

    PubMed

    Vellios, Evan E; Jones, Kristofer J; McAllister, David R

    2018-06-01

    To review the current literature on clinical outcomes following open tibial inlay posterior cruciate ligament (PCL) reconstruction and provide the reader with a detailed description of the author's preferred surgical technique. Despite earlier biomechanical studies which demonstrated superiority of the PCL inlay technique when compared to transtibial techniques, recent longitudinal cohort studies have shown no significant differences in clinical or functional outcomes at 10-year follow-up. Furthermore, no significant clinical differences have been shown between graft types used and/or single- versus double-bundle reconstruction methods. The optimal treatment for the PCL-deficient knee remains unclear. Open tibial inlay PCL reconstruction is safe, reproducible, and avoids the "killer turn" that may potentially lead to graft weakening and failure seen in transtibial reconstruction methods. No significant differences in subjective outcomes or clinical laxity have been shown between single-bundle versus double-bundle reconstruction methods.

  15. The Effect of Arch Drop on Tibial Rotation and Tibiofemoral Contact Stress in Postpartum Women.

    PubMed

    Rabe, Kaitlin; Segal, Neil A; Waheed, Saphia; Anderson, Donald D

    2018-04-26

    Women are at greater risk for knee osteoarthritis and numerous other lower limb musculoskeletal disorders. Arch drop during pregnancy and the resultant excessive pronation of the feet may alter loading patterns and contribute to the greater prevalence of knee osteoarthritis in women. To determine the effect of arch drop on tibial rotation and tibiofemoral contact stress. Interventional study with internal control. Biomechanics laboratory. Eleven postpartum women (age 33.4 ± 5.3 years, body mass 76.1 ± 13.5 kg) who had lost arch height with pregnancy in a previous study. Subjects underwent standing computed tomography (SCT) with their knees in a 20° fixed-flexed position with and without semirigid arch supports to reconstitute prepregnancy arch height. Magnetic resonance imaging of the knee was acquired at a flexion angle equivalent to that of SCT. Bone and cartilage were manually segmented on the magnetic resonance images and segmented surfaces were registered to the 3-dimensional SCT image sets for the arch-supported and -unsupported conditions. These models were used to measure changes in tibial rotation, as well as to estimate contact stress in the medial and lateral tibiofemoral compartments, using computational methods. Change in tibial rotation and tibiofemoral contact stress with arch drop. Arch drop resulted in a mean tibial internal rotation of 0.75 ± 1.33° (P < .05). Changes in mean or peak contact stress were not detected. Arch drop causes internal tibial rotation, resulting in a shift in the tibiofemoral articulation. An associated increase in contact stress was not detected. Internal rotation of the tibia increases stress on the anterior cruciate ligament and menisci, potentially explaining the greater prevalence of knee disorders in postpartum women. Copyright © 2018 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

  16. A modified technique to reduce tibial keel cutting errors during an Oxford unicompartmental knee arthroplasty.

    PubMed

    Inui, Hiroshi; Taketomi, Shuji; Tahara, Keitarou; Yamagami, Ryota; Sanada, Takaki; Tanaka, Sakae

    2017-03-01

    Bone cutting errors can cause malalignment of unicompartmental knee arthroplasties (UKA). Although the extent of tibial malalignment due to horizontal cutting errors has been well reported, there is a lack of studies evaluating malalignment as a consequence of keel cutting errors, particularly in the Oxford UKA. The purpose of this study was to examine keel cutting errors during Oxford UKA placement using a navigation system and to clarify whether two different tibial keel cutting techniques would have different error rates. The alignment of the tibial cut surface after a horizontal osteotomy and the surface of the tibial trial component was measured with a navigation system. Cutting error was defined as the angular difference between these measurements. The following two techniques were used: the standard "pushing" technique in 83 patients (group P) and a modified "dolphin" technique in 41 patients (group D). In all 123 patients studied, the mean absolute keel cutting error was 1.7° and 1.4° in the coronal and sagittal planes, respectively. In group P, there were 22 outlier patients (27 %) in the coronal plane and 13 (16 %) in the sagittal plane. Group D had three outlier patients (8 %) in the coronal plane and none (0 %) in the sagittal plane. Significant differences were observed in the outlier ratio of these techniques in both the sagittal (P = 0.014) and coronal (P = 0.008) planes. Our study demonstrated overall keel cutting errors of 1.7° in the coronal plane and 1.4° in the sagittal plane. The "dolphin" technique was found to significantly reduce keel cutting errors on the tibial side. This technique will be useful for accurate component positioning and therefore improve the longevity of Oxford UKAs. Retrospective comparative study, Level III.

  17. Tibial Bowing and Pseudarthrosis in Neurofibromatosis Type 1

    DTIC Science & Technology

    2015-01-01

    controlling for age and sex was used. However, there were no statistically significant differences between NF1 individuals with and without tibial...Dinorah Friedmann-Morvinski (The Salk Institute) presented a different model of glioblastoma in which tumors were induced from fully differentiated...a driver of Schwann cell tumorigenesis. Induction ofWnt signaling was sufficient to induce a transformed phenotype in human Schwann cells, while

  18. Epidemiology of metatarsal stress fractures versus tibial and femoral stress fractures during elite training.

    PubMed

    Finestone, Aharon; Milgrom, Charles; Wolf, Omer; Petrov, Kaloyan; Evans, Rachel; Moran, Daniel

    2011-01-01

    The training of elite infantry recruits takes a year or more. Stress fractures are known to be endemic in their basic training and the clinical presentation of tibial, femoral, and metatarsal stress fractures are different. Stress fracture incidence during the subsequent progressively more demanding training is not known. The study hypothesis was that after an adaptation period, the incidence of stress fractures during the course of 1 year of elite infantry training would fall in spite of the increasingly demanding training. Seventy-six male elite infantry recruits were followed for the development of stress fractures during a progressively more difficult training program composed of basic training (1 to 14 weeks), advanced training (14 to 26 weeks), and unit training (26 to 52 weeks). Subjects were reviewed regularly and those with clinical suspicion of stress fracture were assessed using bone scan and X-rays. The incidence of stress fractures was 20% during basic training, 14% during advanced training and 23% during unit training. There was a statistically significant difference in the incidence of tibial and femoral stress fractures versus metatarsal stress fractures before and after the completion of phase II training at week 26 (p=0.0001). Seventy-eight percent of the stress fractures during phases I and II training were either tibial or femoral, while 91% of the stress fractures in phase III training were metatarsal. Prior participation in ball sports (p=0.02) and greater tibial length (p=0.05) were protective factors for stress fracture. The study hypothesis that after a period of soldier adaptation, the incidence of stress fractures would decrease in spite of the increasingly demanding elite infantry training was found to be true for tibial and femoral fractures after 6 months of training but not for metatarsal stress fractures. Further studies are required to understand the mechanism of this difference but physicians and others treating stress fractures

  19. Role of high tibial osteotomy in chronic injuries of posterior cruciate ligament and posterolateral corner.

    PubMed

    Savarese, Eugenio; Bisicchia, Salvatore; Romeo, Rocco; Amendola, Annunziato

    2011-03-01

    High tibial osteotomy (HTO) is a surgical procedure used to change the mechanical weight-bearing axis and alter the loads carried through the knee. Conventional indications for HTO are medial compartment osteoarthritis and varus malalignment of the knee causing pain and dysfunction. Traditionally, knee instability associated with varus thrust has been considered a contraindication. However, today the indications include patients with chronic ligament deficiencies and malalignment, because an HTO procedure can change not only the coronal but also the sagittal plane of the knee. The sagittal plane has generally been ignored in HTO literature, but its modification has a significant impact on biomechanics and joint stability. Indeed, decreased posterior tibial slope causes posterior tibia translation and helps the anterior cruciate ligament (ACL)-deficient knee. Vice versa, increased tibial slope causes anterior tibia translation and helps the posterior cruciate ligament (PCL)-deficient knee. A review of literature shows that soft tissue procedures alone are often unsatisfactory for chronic posterior instability if alignment is not corrected. Since limb alignment is the most important factor to consider in lower limb reconstructive surgery, diagnosis and treatment of limb malalignment should not be ignored in management of chronic ligamentous instabilities. This paper reviews the effects of chronic posterior instability and tibial slope alteration on knee and soft tissues, in addition to planning and surgical technique for chronic posterior and posterolateral instability with HTO.

  20. Distinct hip and rearfoot kinematics in female runners with a history of tibial stress fracture.

    PubMed

    Milner, Clare E; Hamill, Joseph; Davis, Irene S

    2010-02-01

    Cross-sectional controlled laboratory study. To investigate the kinematics of the hip, knee, and rearfoot in the frontal and transverse planes in female distance runners with a history of tibial stress fracture. Tibial stress fractures are a common overuse injury in runners, accounting for up to half of all stress fractures. Abnormal kinematics of the lower extremity may contribute to abnormal musculoskeletal load distributions, leading to an increased risk of stress fractures. Thirty female runners with a history of tibial stress fracture were compared to 30 age-matched and weekly-running-distance-matched control subjects with no previous lower extremity bony injuries. Kinematic and kinetic data were collected using a motion capture system and a force platform, respectively, as subjects ran in the laboratory. Selected variables of interest were compared between the groups using a multivariate analysis of variance (MANOVA). Peak hip adduction and peak rearfoot eversion angles were greater in the stress fracture group compared to the control group. Peak knee adduction and knee internal rotation angles and all joint angles at impact peak were similar between the groups. Runners with a previous tibial stress fracture exhibited greater peak hip adduction and rearfoot eversion angles during the stance phase of running compared to healthy controls. A consequence of these mechanics may be altered load distribution within the lower extremity, predisposing individuals to stress fracture.

  1. Hindfoot Valgus following Interlocking Nail Treatment for Tibial Diaphysis Fractures: Can the Fibula Be Neglected?

    PubMed Central

    Uzun, Metin; Kara, Adnan; Adaş, Müjdat; Karslioğlu, Bülent; Bülbül, Murat; Beksaç, Burak

    2014-01-01

    Purpose. We evaluated whether intramedullary nail fixation for tibial diaphysis fractures with concomitant fibula fractures (except at the distal one-third level) managed conservatively with an associated fibula fracture resulted in ankle deformity and assessed the impact of the ankle deformity on lower extremity function. Methods. Sixty middle one-third tibial shaft fractures with associated fibular fractures, except the distal one-third level, were included in this study. All tibial shaft fractures were anatomically reduced and fixed with interlocking intramedullary nails. Fibular fractures were managed conservatively. Hindfoot alignment was assessed clinically. Tibia and fibular lengths were compared to contralateral measurements using radiographs. Functional results were evaluated using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the Foot and Ankle Disability Index Score (FADI). Results. Anatomic union, defined as equal length in operative and contralateral tibias, was achieved in 60 fractures (100%). Fibular shortening was identified in 42 fractures (68%). Mean fibular shortening was 1.2 cm (range, 0.5–2 cm). Clinical exams showed increased hindfoot valgus in 42 fractures (68%). The mean KOOS was 88.4, and the mean FADI score was 90. Conclusion. Fibular fractures in the middle or proximal one-third may need to be stabilized at the time of tibial intramedullary nail fixation to prevent development of hindfoot valgus due to fibular shortening. PMID:25544899

  2. Management of open tibial fractures – a regional experience

    PubMed Central

    Townley, WA; Nguyen, DQA; Rooker, JC; Dickson, JK; Goroszeniuk, DZ; Khan, MS; Camp, D

    2010-01-01

    INTRODUCTION The treatment of soft-tissue injuries associated with tibial diaphyseal fractures presents a clinical challenge that is best managed by a combined plastic and orthopaedic surgery approach. The current study was undertaken to assess early treatment outcomes and burden of service provision across five regional plastic surgery units in the South-West of England. SUBJECTS AND METHODS We conducted a prospective 6-month audit of open tibial diaphyseal fracture management in five plastic surgery units (Bristol, Exeter, Plymouth, Salisbury, Swansea) with a collective catchment of 9.2 million people. Detailed data were collected on patient demographics, injury pattern, surgical management and outcome followed to discharge. RESULTS The study group consisted of 55 patients (40 male, 15 female). Twenty-two patients presented directly to the emergency department at the specialist hospital (primary group), 33 patients were initially managed at a local hospital (tertiary group). The mean time from injury to soft tissue cover was significantly less (P < 0.001) in the primary group (3.6 ± 0.8 days) than the tertiary group (10.8 ± 2.2 days), principally due to a delay in referral in the latter group (5.4 ±1.7 days). Cover was achieved with 39 flaps (19 free, 20 local), eight split skin grafts. Nine wounds closed directly or by secondary intention. There were 11 early complications (20%) including one flap failure and four infections. The overall mean length of stay was 17.5 ± 2.8 days. CONCLUSIONS Multidisciplinary management of severe open tibial diaphyseal may not be feasible at presentation of injury depending on local hospital specialist services available. Our results highlight the need for robust assessment, triage and senior orthopaedic review in the early post-injury phase. However, broader improvements in the management of lower limb trauma will additionally require further development of combined specialist trauma centres. PMID:21047449

  3. Medial tibial pain: a dynamic contrast-enhanced MRI study.

    PubMed

    Mattila, K T; Komu, M E; Dahlström, S; Koskinen, S K; Heikkilä, J

    1999-09-01

    The purpose of this study was to compare the sensitivity of different magnetic resonance imaging (MRI) sequences to depict periosteal edema in patients with medial tibial pain. Additionally, we evaluated the ability of dynamic contrast-enhanced imaging (DCES) to depict possible temporal alterations in muscular perfusion within compartments of the leg. Fifteen patients with medial tibial pain were examined with MRI. T1-, T2-weighted, proton density axial images and dynamic and static phase post-contrast images were compared in ability to depict periosteal edema. STIR was used in seven cases to depict bone marrow edema. Images were analyzed to detect signs of compartment edema. Region-of-interest measurements in compartments were performed during DCES and compared with controls. In detecting periosteal edema, post-contrast T1-weighted images were better than spin echo T2-weighted and proton density images or STIR images, but STIR depicted the bone marrow edema best. DCES best demonstrated the gradually enhancing periostitis. Four subjects with severe periosteal edema had visually detectable pathologic enhancement during DCES in the deep posterior compartment of the leg. Percentage enhancement in the deep posterior compartment of the leg was greater in patients than in controls. The fast enhancement phase in the deep posterior compartment began slightly slower in patients than in controls, but it continued longer. We believe that periosteal edema in bone stress reaction can cause impairment of venous flow in the deep posterior compartment. MRI can depict both these conditions. In patients with medial tibial pain, MR imaging protocol should include axial STIR images (to depict bone pathology) with T1-weighted axial pre and post-contrast images, and dynamic contrast enhanced imaging to show periosteal edema and abnormal contrast enhancement within a compartment.

  4. Effect of axial tibial torque direction on ACL relative strain and strain rate in an in vitro simulated pivot landing.

    PubMed

    Oh, Youkeun K; Kreinbrink, Jennifer L; Wojtys, Edward M; Ashton-Miller, James A

    2012-04-01

    Anterior cruciate ligament (ACL) injuries most frequently occur under the large loads associated with a unipedal jump landing involving a cutting or pivoting maneuver. We tested the hypotheses that internal tibial torque would increase the anteromedial (AM) bundle ACL relative strain and strain rate more than would the corresponding external tibial torque under the large impulsive loads associated with such landing maneuvers. Twelve cadaveric female knees [mean (SD) age: 65.0 (10.5) years] were tested. Pretensioned quadriceps, hamstring, and gastrocnemius muscle-tendon unit forces maintained an initial knee flexion angle of 15°. A compound impulsive test load (compression, flexion moment, and internal or external tibial torque) was applied to the distal tibia while recording the 3D knee loads and tibofemoral kinematics. AM-ACL relative strain was measured using a 3 mm DVRT. In this repeated measures experiment, the Wilcoxon signed-rank test was used to test the null hypotheses with p < 0.05 considered significant. The mean (±SD) peak AM-ACL relative strains were 5.4 ± 3.7% and 3.1 ± 2.8% under internal and external tibial torque, respectively. The corresponding mean (± SD) peak AM-ACL strain rates reached 254.4 ± 160.1%/s and 179.4 ± 109.9%/s, respectively. The hypotheses were supported in that the normalized mean peak AM-ACL relative strain and strain rate were 70 and 42% greater under internal than under external tibial torque, respectively (p = 0.023, p = 0.041). We conclude that internal tibial torque is a potent stressor of the ACL because it induces a considerably (70%) larger peak strain in the AM-ACL than does a corresponding external tibial torque. Copyright © 2011 Orthopaedic Research Society.

  5. Ketorolac Administered in the Recovery Room for Acute Pain Management Does Not Affect Healing Rates of Femoral and Tibial Fractures.

    PubMed

    Donohue, David; Sanders, Drew; Serrano-Riera, Rafa; Jordan, Charles; Gaskins, Roger; Sanders, Roy; Sagi, H Claude

    2016-09-01

    To determine whether ketorolac administered in the immediate perioperative period affects the rate of nonunion in femoral and tibial shaft fractures. Retrospective comparative study. Single Institution, Academic Level 1 Trauma Center. Three hundred and thirteen skeletally mature patients with 137 femoral shaft (OTA 32) and 191 tibial shaft (OTA 42) fractures treated with intramedullary rod fixation. Eighty patients with 33 femoral shaft and 52 tibial shaft fractures were administered ketorolac within the first 24 hours after surgery (group 1-study group). Two-hundred thirty-three patients with 104 femoral shaft and 139 tibial shaft fractures were not (group 2-control group). Rate of reoperation for repair of a nonunion and time to union. Average time to union of the femur was 147 days for group 1 and 159 days for group 2 (P = 0.57). Average time to union of the tibia was 175 days for group 1 and 175 days for group 2 (P = 0.57). There were 3 femoral nonunions (9%) in group 1 and eleven femoral nonunions (11.6%) in group 2 (P = 1.00). There were 3 tibial nonunions (5.8%) in group 1 and 17 tibial nonunions (12.2%) in group 2 (P = 0.29). The average dose of ketorolac for patients who healed their fracture was 85 mg, whereas it was 50 mg for those who did not (P = 0.27). All patients with a nonunion in the study group were current smokers. Ketorolac administered in the first 24 hours after fracture repair for acute pain management does not seem to have a negative impact on time to healing or incidence of nonunion for femoral or tibial shaft fractures. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

  6. EFFECT OF AXIAL TIBIAL TORQUE DIRECTION ON ACL RELATIVE STRAIN AND STRAIN RATE IN AN IN VITRO SIMULATED PIVOT LANDING

    PubMed Central

    Oh, Youkeun K.; Kreinbrink, Jennifer L.; Wojtys, Edward M.; Ashton-Miller, James A.

    2011-01-01

    Anterior cruciate ligament (ACL) injuries most frequently occur under the large loads associated with a unipedal jump landing involving a cutting or pivoting maneuver. We tested the hypotheses that internal tibial torque would increase the anteromedial (AM) bundle ACL relative strain and strain rate more than would the corresponding external tibial torque under the large impulsive loads associated with such landing maneuvers. Twelve cadaveric female knees [mean (SD) age: 65.0 (10.5) years] were tested. Pretensioned quadriceps, hamstring and gastrocnemius muscle-tendon unit forces maintained an initial knee flexion angle of 15°. A compound impulsive test load (compression, flexion moment and internal or external tibial torque) was applied to the distal tibia while recording the 3-D knee loads and tibofemoral kinematics. AM-ACL relative strain was measured using a 3mm DVRT. In this repeated measures experiment, the Wilcoxon Signed-Rank test was used to test the null hypotheses with p<0.05 considered significant. The mean (± SD) peak AM-ACL relative strains were 5.4±3.7 % and 3.1±2.8 % under internal and external tibial torque, respectively. The corresponding mean (± SD) peak AM-ACL strain rates reached 254.4±160.1 %/sec and 179.4±109.9 %/sec, respectively. The hypotheses were supported in that the normalized mean peak AM-ACL relative strain and strain rate were 70% and 42% greater under internal than external tibial torque, respectively (p=0.023, p=0.041). We conclude that internal tibial torque is a potent stressor of the ACL because it induces a considerably (70%) larger peak strain in the AM-ACL than does a corresponding external tibial torque. PMID:22025178

  7. Minimally invasive treatment of tibial pilon fractures through arthroscopy and external fixator-assisted reduction.

    PubMed

    Luo, Huasong; Chen, Liaobin; Liu, Kebin; Peng, Songming; Zhang, Jien; Yi, Yang

    2016-01-01

    The aim of this study was to evaluate the clinical outcome of tibial pilon fractures treated with arthroscopy and assisted reduction with an external fixator. Thirteen patients with tibial pilon fractures underwent assisted reduction for limited lower internal fixation with an external fixator under arthroscopic guidance. The weight-bearing time was decided on the basis of repeat radiography of the tibia 3 months after surgery. Postoperative ankle function was evaluated according to the Mazur scoring system. Healing of fractures was achieved in all cases, with no complications such as severe infection, skin necrosis, or an exposed plate. There were 9 excellent, 2 good, and 2 poor outcomes, scored according to the Mazur system. The acceptance rate was 85%. Arthroscopy and external fixator-assisted reduction for the minimally invasive treatment of tibial pilon fractures not only produced less trauma but also protected the soft tissues and blood supply surrounding the fractures. External fixation could indirectly provide reduction and effective operative space for arthroscopic implantation, especially for AO type B fractures and partial AO type C1 fractures.

  8. Tibial dyschondroplasia associated proteomic changes in chicken growth plate cartilage

    USDA-ARS?s Scientific Manuscript database

    Tibial dyschondroplasia (TD) is a poultry leg problem that affects the proximal growth plate of tibia preventing its transition to bone. To understand the disease-induced proteomic changes we compared the protein extracts of cartilage from normal and TD- affected growth plates. TD was induced by fe...

  9. Primary stability of different plate positions and the role of bone substitute in open wedge high tibial osteotomy.

    PubMed

    Takeuchi, Ryohei; Woon-Hwa, Jung; Ishikawa, Hiroyuki; Yamaguchi, Yuichiro; Osawa, Katsunari; Akamatsu, Yasushi; Kuroda, Koichi

    2017-12-01

    The purpose of this study was to compare the mechanical fixation strengths of anteromedial and medial plate positions in osteotomy, and clarify the effects of bone substitute placement into the osteotomy site. Twenty-eight sawbone tibia models were used. Four different models were prepared: Group A, the osteotomy site was open and the plate position was anteromedial; Group B, bone substitutes were inserted into the osteotomy site and the plate position was anteromedial; Group C, the osteotomy site was open and the plate position was medial; and Group D, bone substitutes were inserted into the osteotomy site and the plate position was medial. The loading condition ranged from 0 to 800N and one hertz cycles were applied. Changes of the tibial posterior slope angle (TPS), stress on the plate and lateral hinge were measured. The changes in the TPS and the stress on the plate were significantly larger in Group A than in Group C. These were significantly larger in Group A than in Group B, and in Group C than in Group D. There was no significant difference between Group B and Group D, and no significant difference between knee flexion angles of 0° and 10°. Stress on the lateral hinge was significantly smaller when bone substitute was used. A medial plate position was biomechanically superior to an anteromedial position if bone substitute was not used. Bone substitute distributed the stress concentration around the osteotomy gap and prevented an increase in TPS angle regardless of the plate position. Copyright © 2017. Published by Elsevier B.V.

  10. A new aiming guide can create the tibial tunnel at favorable position in transtibial pullout repair for the medial meniscus posterior root tear.

    PubMed

    Furumatsu, T; Kodama, Y; Fujii, M; Tanaka, T; Hino, T; Kamatsuki, Y; Yamada, K; Miyazawa, S; Ozaki, T

    2017-05-01

    Injuries to the medial meniscus (MM) posterior root lead to accelerated cartilage degeneration of the knee. An anatomic placement of the MM posterior root attachment is considered to be critical in transtibial pullout repair of the medial meniscus posterior root tear (MMPRT). However, tibial tunnel creation at the anatomic attachment of the MM posterior root is technically difficult using a conventional aiming device. The aim of this study was to compare two aiming guides. We hypothesized that a newly-developed guide, specifically designed, creates the tibial tunnel at an adequate position rather than a conventional device. Twenty-six patients underwent transtibial pullout repairs. Tibial tunnel creation was performed using the Multi-use guide (8 cases) or the PRT guide that had a narrow twisting/curving shape (18 cases). Three-dimensional computed tomography images of the tibial surface were evaluated using the Tsukada's measurement method postoperatively. Expected anatomic center of the MM posterior root attachment and tibial tunnel center were evaluated using the percentage-based posterolateral location on the tibial surface. Percentage distance between anatomic center and tunnel center was calculated. Anatomic center of the MM posterior root footprint located at a position of 78.5% posterior and 39.4% lateral. Both tunnels were anteromedial but tibial tunnel center located at a more favorable position in the PRT group: percentage distance was significantly smaller in the PRT guide group (8.7%) than in the Multi-use guide group (13.1%). The PRT guide may have great advantage to achieve a more anatomic location of the tibial tunnel in MMPRT pullout repair. III. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  11. Tibial Plateau Fractures in Elderly Patients

    PubMed Central

    Vemulapalli, Krishna C.; Gary, Joshua L.; Donegan, Derek J.

    2016-01-01

    Tibial plateau fractures are common in the elderly population following a low-energy mechanism. Initial evaluation includes an assessment of the soft tissues and surrounding ligaments. Most fractures involve articular depression leading to joint incongruity. Treatment of these fractures may be complicated by osteoporosis, osteoarthritis, and medical comorbidities. Optimal reconstruction should restore the mechanical axis, provide a stable construct for mobilization, and reestablish articular congruity. This is accomplished through a variety of internal or external fixation techniques or with acute arthroplasty. Regardless of the treatment modality, particular focus on preservation and maintenance of the soft tissue envelope is paramount. PMID:27551570

  12. External versus internal fixation for bicondylar tibial plateau fractures: systematic review and meta-analysis.

    PubMed

    Metcalfe, David; Hickson, Craig J; McKee, Lesley; Griffin, Xavier L

    2015-12-01

    It is uncertain whether external fixation or open reduction internal fixation (ORIF) is optimal for patients with bicondylar tibial plateau fractures. A systematic review using Ovid MEDLINE, Embase Classic, Embase, AMED, the Cochrane Library, Open Grey, Orthopaedic Proceedings, WHO International Clinical Trials Registry Platform, Current Controlled Trials, US National Institute for Health Trials Registry, and the Cochrane Central Register of Controlled Trials. The search was conducted on 3rd October 2014 and no language limits were applied. Inclusion criteria were all clinical study designs comparing external fixation with open reduction internal fixation of bicondylar tibial plateau fractures. Studies of only one treatment modality were excluded, as were those that included unicondylar tibial plateau fractures. Treatment effects from studies reporting dichotomous outcomes were summarised using odds ratios. Continuous outcomes were converted to standardized mean differences to assess the treatment effect, and inverse variance methods used to combine data. A fixed effect model was used for meta-analyses. Patients undergoing external fixation were more likely to have returned to preinjury activities by six and twelve months (P = 0.030) but not at 24 months follow-up. However, external fixation was complicated by a greater number of infections (OR 2.59, 95 % CI 1.25-5.36, P = 0.01). There were no statistically significant differences in the rates of deep infection, venous thromboembolism, compartment syndrome, or need for re-operation between the two groups. Although external fixation and ORIF are associated with different complication profiles, both are acceptable strategies for managing bicondylar tibial plateau fractures.

  13. Contact Kinematics Correlates to Tibial Component Migration Following Single Radius Posterior Stabilized Knee Replacement.

    PubMed

    Teeter, Matthew G; Perry, Kevin I; Yuan, Xunhua; Howard, James L; Lanting, Brent A

    2018-03-01

    Contact kinematics between total knee arthroplasty components is thought to affect implant migration; however, the interaction between kinematics and tibial component migration has not been thoroughly examined in a modern implant system. A total of 24 knees from 23 patients undergoing total knee arthroplasty with a single radius, posterior stabilized implant were examined. Patients underwent radiostereometric analysis at 2 and 6 weeks, 3 and 6 months, and 1 and 2 years to measure migration of the tibial component in all planes. At 1 year, patients also had standing radiostereometric analysis examinations acquired in 0°, 20°, 40°, and 60° of flexion, and the location of contact and magnitude of any condylar liftoff was measured for each flexion angle. Regression analysis was performed between kinematic variables and migration at 1 year. The average magnitude of maximum total point motion across all patients was 0.671 ± 0.270 mm at 1 year and 0.608 ± 0.359 mm at 2 years (P = .327). Four implants demonstrated continuous migration of >0.2 mm between the first and second year of implantation. There were correlations between the location of contact and tibial component anterior-posterior tilt, varus-valgus tilt, and anterior-posterior translation. The patients with continuous migration demonstrated atypical kinematics and condylar liftoff in some instances. Kinematics can influence tibial component migration, likely through alterations of force transmission. Abnormal kinematics may play a role in long-term implant loosening. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Tibial nerve stimulation for overactive bladder syndrome unresponsive to medical therapy.

    PubMed

    Ridout, A E; Yoong, W

    2010-02-01

    Overactive bladder syndrome is defined as a symptom syndrome which includes urinary urgency, with or without urge incontinence, usually accompanied by frequency (>8 micturitions/24 h) and nocturia. Conservative treatment usually comprises behavioural techniques, bladder retraining, pelvic floor re-education and pharmacotherapy but up to 30% of patients will remain refractory to treatment. Although second-line treatment options such as sacral nerve stimulation and intravesical botulinum A injections are valuable additions to the therapeutic arsenal, they are relatively invasive and can have serious side-effects. Inhibition of detrusor activity by peripheral neuromodulation of the posterior tibial nerve was first described in 1983, with recent authors further confirming a 60-80% positive response rate. This review was undertaken to examine published literature on percutaneous tibial nerve stimulation and to discuss outcome measures, maintenance therapy and prognostic factors of this technique.

  15. Increases in tibial force imbalance but not changes in tibiofemoral laxities are caused by varus-valgus malalignment of the femoral component in kinematically aligned TKA.

    PubMed

    Riley, Jeremy; Roth, Joshua D; Howell, Stephen M; Hull, Maury L

    2018-01-29

    The purposes of this study were to quantify the increase in tibial force imbalance (i.e. magnitude of difference between medial and lateral tibial forces) and changes in laxities caused by 2° and 4° of varus-valgus (V-V) malalignment of the femoral component in kinematically aligned total knee arthroplasty (TKA) and use the results to detemine sensitivities to errors in making the distal femoral resections. Because V-V malalignment would introduce the greatest changes in the alignment of the articular surfaces at 0° flexion, the hypotheses were that the greatest increases in tibial force imbalance would occur at 0° flexion, that primarily V-V laxity would significantly change at this flexion angle, and that the tibial force imbalance would increase and laxities would change in proportion to the degree of V-V malalignment. Kinematically aligned TKA was performed on ten human cadaveric knee specimens using disposable manual instruments without soft tissue release. One 3D-printed reference femoral component, with unmodified geometry, was aligned to restore the native distal and posterior femoral joint lines. Four 3D-printed femoral components, with modified geometry, introduced V-V malalignments of 2° and 4° from the reference component. Medial and lateral tibial forces were measured during passive knee flexion-extension between 0° to 120° using a custom tibial force sensor. Eight laxities were measured from 0° to 120° flexion using a six degree-of-freedom load application system. With the tibial component kinematically aligned, the increase in the tibial force imbalance from that of the reference component at 0° of flexion was sensitive to the degree of V-V malalignment of the femoral component. Sensitivities were 54 N/deg (medial tibial force increasing > lateral tibial force) (p < 0.0024) and 44 N/deg (lateral tibial force increasing > medial tibial force) (p < 0.0077) for varus and valgus malalignments, respectively. Varus

  16. Risk of total knee arthroplasty after operatively treated tibial plateau fracture: a matched-population-based cohort study.

    PubMed

    Wasserstein, David; Henry, Patrick; Paterson, J Michael; Kreder, Hans J; Jenkinson, Richard

    2014-01-15

    The aims of operative treatment of displaced tibial plateau fractures are to stabilize the injured knee to restore optimal function and to minimize the risk of posttraumatic arthritis and the eventual need for total knee arthroplasty. The purpose of our study was to define the rate of subsequent total knee arthroplasty after tibial plateau fractures in a large cohort and to compare that rate with the rate in the general population. All patients sixteen years of age or older who had undergone surgical treatment of a tibial plateau fracture from 1996 to 2009 in the province of Ontario, Canada, were identified from administrative health databases with use of surgeon fee codes. Each member of the tibial plateau fracture cohort was matched to four individuals from the general population according to age, sex, income, and urban/rural residence. The rates of total knee arthroplasty at two, five, and ten years were compared by using time-to-event analysis. A separate Cox proportional hazards model was used to explore the influence of patient, provider, and surgical factors on the time to total knee arthroplasty. We identified 8426 patients (48.5% female; median age, 48.9 years) who had undergone fixation of a tibial plateau fracture and matched them to 33,698 controls. The two, five, and ten-year rates of total knee arthroplasty in the plateau fracture and control cohorts were 0.32% versus 0.29%, 5.3% versus 0.82%, and 7.3% versus 1.8%, respectively (p < 0.0001). After adjustment for comorbidity, plateau fracture surgery was found to significantly increase the likelihood of total knee arthroplasty (hazard ratio [HR], 5.29 [95% confidence interval, 4.58, 6.11]; p < 0.0001). Higher rates of total knee arthroplasty were also associated with increasing age (HR, 1.03 [1.03, 1.04] per year over the age of forty-eight; p < 0.0001), bicondylar fracture (HR, 1.53 [1.26, 1.84]; p < 0.0001), and greater comorbidity (HR, 2.17 [1.70, 2.77]; p < 0.001). Ten years after tibial plateau

  17. Internal-external malalignment of the femoral component in kinematically aligned total knee arthroplasty increases tibial force imbalance but does not change laxities of the tibiofemoral joint.

    PubMed

    Riley, Jeremy; Roth, Joshua D; Howell, Stephen M; Hull, Maury L

    2018-06-01

    The purposes of this study were to quantify the increase in tibial force imbalance (i.e. magnitude of difference between medial and lateral tibial forces) and changes in laxities caused by  2° and 4° of internal-external (I-E) malalignment of the femoral component in kinematically aligned total knee arthroplasty. Because I-E malalignment would introduce the greatest changes to the articular surfaces near 90° of flexion, the hypotheses were that the tibial force imbalance would be significantly increased near 90° flexion and that primarily varus-valgus laxity would be affected near 90° flexion. Kinematically aligned TKA was performed on ten human cadaveric knee specimens using disposable manual instruments without soft tissue release. One 3D-printed reference femoral component, with unmodified geometry, was aligned to restore the native distal and posterior femoral joint lines. Four 3D-printed femoral components, with modified geometry, introduced I-E malalignments of 2° and 4° from the reference component. Medial and lateral tibial forces were measured from 0° to 120° flexion using a custom tibial force sensor. Bidirectional laxities in four degrees of freedom were measured from 0° to 120° flexion using a custom load application system. Tibial force imbalance increased the greatest at 60° flexion where a regression analysis against the degree of I-E malalignment yielded sensitivities (i.e. slopes) of 30 N/° (medial tibial force > lateral tibial force) and 10 N/° (lateral tibial force > medial tibial force) for internal and external malalignments, respectively. Valgus laxity increased significantly with the 4° external component with the greatest increase of 1.5° occurring at 90° flexion (p < 0.0001). With the tibial component correctly aligned, I-E malalignment of the femoral component caused significant increases in tibial force imbalance. Minimizing I-E malalignment lowers the increase in the tibial force imbalance. By keeping

  18. Tibial plateau fracture after anterior cruciate ligament reconstruction: Role of the interference screw resorption in the stress riser effect.

    PubMed

    Thaunat, Mathieu; Nourissat, Geoffroy; Gaudin, Pascal; Beaufils, Philippe

    2006-06-01

    We report a case of tibial plateau fracture after previous anterior cruciate ligament (ACL) reconstruction using patellar tendon autograft and bioabsorbable screws 4 years previously. The fracture occurred through the tibial tunnel. The interference screw had undergone complete resorption and the tunnel widening had increased. The resorption of the interference screw did not simultaneously promote and foster the growth of surrounding bone tissue. Therefore, the area of reactive tissue left by the screw resorption in an enlarged bone tunnel may lead to vulnerability of the tibial plateau. Stress risers would occur following ACL reconstruction if either resorption is not complete or bony integration is not complete.

  19. Symptomatic venous thromboembolism following circular frame treatment for tibial fractures.

    PubMed

    Vollans, S; Chaturvedi, A; Sivasankaran, K; Madhu, T; Hadland, Y; Allgar, V; Sharma, H K

    2015-01-01

    Venous thromboembolism (VTE) is a significant cause of morbidity and mortality following tibial fractures. The risk is as high as 77% without prophylaxis and around 10% with prophylaxis. Within the current literature there are no figures reported specifically for those individuals treated with circular frames. Our aim was to evaluate the VTE incidence within a single surgeon series and to evaluate potential risk factors. We retrospectively reviewed our consecutive single surgeon series of 177 patients admitted to a major trauma unit with tibial fractures. All patients received standardised care, including chemical thromboprophylaxis within 24h of injury until independent mobility was achieved. We comprehensively reviewed our prospective database and medical records looking at demographics and potential risk factors. Seven patients (4.0% ± 2.87%) developed symptomatic VTE during the course of frame treatment; three deep vein thrombosis (DVTs) and four pulmonary embolisms (PEs). Those with a VTE event had significantly increased body mass index (BMI) (p = 0.01) when compared to those without symptomatic VTE. No differences (p > 0.05) were observed between the groups in age, gender, smoking status, fracture type (anatomical allocation or open/closed), delay to frame treatment, weight bearing status post-frame, inpatient stay or total duration of frame treatment. This study suggests that increased BMI is a statistically significant risk factor for VTE, as reported in current literature. In addition, we calculated the true risk of VTE following circular frame treatment for tibial fracture in our series is from 1.13% to 6.87%, which is at least comparable to other forms of treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Popliteal versus tibial retrograde access for subintimal arterial flossing with antegrade-retrograde intervention (SAFARI) technique.

    PubMed

    Hua, W R; Yi, M Q; Min, T L; Feng, S N; Xuan, L Z; Xing, J

    2013-08-01

    This study aimed to ascertain differences in benefit and effectiveness of popliteal versus tibial retrograde access in subintimal arterial flossing with the antegrade-retrograde intervention (SAFARI) technique. This was a retrospective study of SAFARI-assisted stenting for long chronic total occlusion (CTO) of TASC C and D superficial femoral lesions. 38 cases had superficial femoral artery lesions (23 TASC C and 15 TASC D). All 38 cases underwent SAFARI-assisted stenting. The ipsilateral popliteal artery was retrogradely punctured in 17 patients. A distal posterior tibial (PT) or dorsalis pedis (DP) artery was retrogradely punctured in 21 patients, and 16 of them were punctured after open surgical exposure. SAFARI technical success was achieved in all cases. There was no significant difference in 1-year primary patency (75% vs. 78.9%, p = .86), secondary patency (81.2% vs. 84.2%, p = .91) and access complications (p = 1.00) between popliteal and tibial retrograde access. There was statistical difference in operation time between popliteal (140.1 ± 28.4 min) and tibial retrograde access with PT/DP punctures after surgical vessel exposure (120.4 ± 23.0 min, p = .04). The SAFARI technique is a safe and feasible option for patients with infrainguinal CTO (TASC II C and D). The PT or DP as the retrograde access after surgical vessel exposure is a good choice when using the SAFARI technique. Copyright © 2013 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

  1. High altitude hypoxia as a factor that promotes tibial growth plate development in broiler chickens

    PubMed Central

    Huang, Shucheng; Zhang, Lihong; Rehman, Mujeeb Ur; Iqbal, Muhammad Kashif; Lan, Yanfang; Mehmood, Khalid; Zhang, Hui; Qiu, Gang; Nabi, Fazul; Yao, Wangyuan; Wang, Meng; Li, Jiakui

    2017-01-01

    Tibial dyschondroplasia (TD) is one of the most common problems in the poultry industry and leads to lameness by affecting the proximal growth plate of the tibia. However, due to the unique environmental and geographical conditions of Tibet, no case of TD has been reported in Tibetan chickens (TBCs). The present study was designed to investigate the effect of high altitude hypoxia on blood parameters and tibial growth plate development in chickens using the complete blood count, morphology, and histological examination. The results of this study showed an undesirable impact on the overall performance, body weight, and mortality of Arbor Acres chickens (AACs) exposed to a high altitude hypoxic environment. However, AACs raised under hypoxic conditions showed an elevated number of red blood cells (RBCs) and an increase in hemoglobin and hematocrit values on day 14 compared to the hypobaric normoxia group. Notably, the morphology and histology analyses showed that the size of tibial growth plates in AACs was enlarged and that the blood vessel density was also higher after exposure to the hypoxic environment for 14 days, while no such change was observed in TBCs. Altogether, our results revealed that the hypoxic environment has a potentially new role in increasing the blood vessel density of proximal tibial growth plates to strengthen and enhance the size of the growth plates, which may provide new insights for the therapeutic manipulation of hypoxia in poultry TD. PMID:28282429

  2. Turbine vane segment and impingement insert configuration for fail-safe impingement insert retention

    DOEpatents

    Burdgick, Steven Sebastian; Kellock, Iain Robertson

    2003-05-13

    An impingement insert sleeve is provided that is adapted to be disposed in a coolant cavity defined through a stator vane. The insert has a generally open inlet end and first and second pairs of diametrically opposed side walls, and at least one fail-safe tab defined at a longitudinal end of the insert for limiting radial displacement of the insert with respect to the stator vane.

  3. Opening-wedge high tibial osteotomy with a locked low-profile plate: surgical technique.

    PubMed

    Kolb, Werner; Guhlmann, Hanno; Windisch, Christoph; Koller, Heiko; Grützner, Paul; Kolb, Klaus

    2010-09-01

    High tibial osteotomy has been recognized as a beneficial treatment for osteoarthritis of the medial compartment of the knee. The purpose of this prospective study was to assess the short-term results of opening-wedge high tibial osteotomies with locked plate fixation. From September 2002 to November 2005, fifty-one consecutive medial opening-wedge high tibial osteotomies were performed. The mean age of the patients at the time of the index operation was forty-nine years. The preoperative and postoperative factors analyzed included the grade of arthritis of the tibiofemoral compartment (the Ahlbäck radiographic grade), the anatomic tibiofemoral angle, patellar height, the Hospital for Special Surgery rating system score, and the Lysholm and Gillquist knee score. Postoperatively, one superficial wound infection occurred. Fifty of the fifty-one osteotomies healed after an average period of 12.9 weeks (range, eight to sixteen weeks) without bone grafts. A nonunion developed in a sixty-two-year-old patient who was a cigarette smoker. The average postoperative tibiofemoral angle was 9° of valgus. Forty-nine patients were followed for a mean of fifty-two months. The average score on the Hospital for Special Surgery rating system was 86 points at the time of the most recent follow-up. The rating was excellent in twenty-eight patients (57%), good in twelve (24%), fair in four (8%), and poor in five (10%). The average score on the Lysholm and Gillquist knee-scoring scale was 83 points. According to these scores, the outcome was excellent in nine patients (18%), good in thirty-one (63%), fair in three (6%), and poor in six (12%). Four knees failed after an average of thirty-six months. Our results suggest that an opening-wedge high tibial osteotomy with locked plate fixation allows a correct valgus angle to be achieved with good short-term results.

  4. Evaluation of cranial tibial and extensor carpi radialis reflexes before and after anesthetic block in cats.

    PubMed

    Tudury, Eduardo Alberto; de Figueiredo, Marcella Luiz; Fernandes, Thaiza Helena Tavares; Araújo, Bruno Martins; Bonelli, Marília de Albuquerque; Diogo, Camila Cardoso; Silva, Amanda Camilo; Santos, Cássia Regina Oliveira; Rocha, Nadyne Lorrayne Farias Cardoso

    2017-02-01

    Objectives This study aimed to test the extensor carpi radialis and cranial tibial reflexes in cats before and after anesthetic block of the brachial and lumbosacral plexus, respectively, to determine whether they depend on a myotatic reflex arc. Methods Fifty-five cats with a normal neurologic examination that were referred for elective gonadectomy were divided into group 1 (29 cats) for testing the extensor carpi radialis reflex, and group 2 (26 cats) for testing the cranial tibial reflex. In group 1, the extensor carpi radialis reflex was tested after anesthetic induction and 15 mins after brachial plexus block with lidocaine. In group 2, the cranial tibial, withdrawal and patellar reflexes were elicited in 52 hindlimbs and retested 15 mins after epidural anesthesia. Results In group 1, before the anesthetic block, 55.17% of the cats had a decreased and 44.83% had a normal extensor carpi radialis reflex. After the block, 68.96% showed a decreased and 27.59% a normal reflex. No cat had an increased or absent reflex before anesthetic block. In group 2, prior to the anesthetic block, 15.38% of the cats had a decreased cranial tibial reflex and 84.62% had a normal response, whereas after the block it was decreased in 26.92% and normal in 73.08% of the cats. None of the cats had an increased or absent reflex. Regarding the presence of both reflexes before and after anesthetic block, there was no significant difference at 1% ( P = 0.013). Conclusions and relevance The extensor carpi radialis and cranial tibial reflexes in cats are not strictly myotatic reflexes, as they are independent of the reflex arc, and may be idiomuscular responses. Therefore, they are not reliable for neurologic examination in this species.

  5. Landing strategies focusing on the control of tibial rotation in the initial contact period of one-leg forward hops.

    PubMed

    Chen, W-L; Chen, Y-T; Huang, S-Y; Yang, C-Y; Wu, C-D; Chang, C-W

    2017-08-01

    Anterior cruciate ligament (ACL) reconstruction (ACLR) surgeries successfully restore anterior tibial translation but not tibial rotation. This study aimed to explore landing strategies focusing on the control of tibial rotation at landing when the ACL is most vulnerable. Three groups of male subjects (50 ACLRs, 26 basketball players, and 31 controls) participated in one-leg forward hop tests for determining the tibial rotatory landing strategies adopted during the initial landing phase. The differences in knee kinematics and muscle activities between internal and external tibial rotatory (ITR, ETR) landing strategies were examined. A higher proportion of basketball players (34.6%) were found to adopt ITR strategies (controls: 6.5%), exhibiting significantly greater hopping distance and knee strength. After adjusting for hopping distance, subjects adopting ITR strategies were found to hop faster with straighter knees at foot contact and with greater ITR and less knee adduction angular displacement during the initial landing phase. However, significantly greater angular displacement in knee flexion, greater medial hamstring activities, and greater co-contraction index of hamstrings and medial knee muscles were also found during initial landing. Our results support the importance of the recruitments of medial hamstrings or the local co-contraction in assisting the rotatory control of the knee during initial landing for avoiding ACL injuries. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Trampoline fracture of the proximal tibial metaphysis in children may not progress into valgus: a report of seven cases and a brief review.

    PubMed

    Kakel, R

    2012-06-01

    Fracture of the proximal tibial metaphysis in children is a rare injury but notorious for carrying the risk of subsequent valgus deformity of the tibia. Trampoline-caused fracture of the proximal tibial metaphysis in children may not progress into valgus. We followed up six children who collectively sustained seven fractures of the proximal tibial metaphysis while trampolining with other heavier and/or older children. Initial and follow-up x-rays were reviewed by an orthopaedic surgeons and two radiologists. None of the patients developed valgus deformity with follow-up. Trampoline is associated with a specific type of injury to the proximal tibia when children are trampolining with other heavier children even without falling off the trampoline. This fracture is linear and complete, often non-displaced. Unlike "other" proximal tibial metaphyseal fractures, trampoline-associated proximal tibial metaphysical fracture in children is not associated with a risk of subsequent valgus deformity. Level 4. case series. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  7. Anatomy, function, and pathophysiology of the posterior tibial tendon.

    PubMed

    Smith, C F

    1999-07-01

    The posterior tibial tendon is vital for the structure and function of the foot and ankle. Dysfunction of the tendon can be debilitating and devastating. In recent years, much attention had been directed toward the diagnosis and treatment of PTTD. To properly diagnose and devise an appropriate treatment regimen, the anatomy, function, and pathophysiology associated with PTTD need to be thoroughly understood.

  8. Teleoperated master-slave needle insertion.

    PubMed

    Abolhassani, Niki; Patel, Rajni V

    2009-12-01

    Accuracy of needle tip placement and needle tracking in soft tissue are of particular importance in many medical procedures. In recent years, developing autonomous and teleoperated systems for needle insertion has become an active area of research. In this study, needle insertion was performed using a master-slave set-up with multi-degrees of freedom. The effect of force feedback on the accuracy of needle insertion was investigated. In addition, this study compared autonomous, teleoperated and semi-autonomous needle insertion. The results of this study show that incorporation of force feedback can improve teleoperated needle insertion. However, autonomous and semi-autonomous needle insertions, which use feedback from a deflection model, provide significantly better performance. Development of a haptic master-slave needle insertion system, which is capable of performing some autonomous tasks based on feedback from tissue deformation and needle deflection models, can improve the performance of autonomous robotics-based insertions as well as non-autonomous teleoperated manual insertions. Copyright (c) 2009 John Wiley & Sons, Ltd.

  9. Leg Muscle Usage on Tibial Elasticity During Running

    DTIC Science & Technology

    2005-01-01

    relative risk of forefoot versus heel- strike running. In summary, there is no evidence in the literature that either study arm is at more risk than...tested in TSF, or even studied in runners. These basic validation studies will determine if modulators of tibial stress, .such as heel- strike mechanics...the other for acute injuries, although it was agreed that forefoot runners will be periodically evaluated for injuries to the Achilles tendon. After

  10. Multiple Tibial Insufficiency Fractures in the Same Tibia

    PubMed Central

    Defoort, Saartje; Mertens, Peter

    2011-01-01

    Stress fractures were first described by Briethaupt in 1855. Since then, there have been many discussions in the literature concerning stress fractures, which have been described in both weight-bearing and non-weight-bearing bones. Currently, the tibia is the most frequent location, but multiple stress fractures in the same tibia are rare. This paper presents an unusual case of a 60-year-old woman with multiple tibial stress fractures of spontaneous onset. PMID:23569673

  11. External fixation combined with delayed internal fixation in treatment of tibial plateau fractures with dislocation.

    PubMed

    Tao, Xingguang; Chen, Nong; Pan, Fugen; Cheng, Biao

    2017-10-01

    The aim of this study was to evaluate the clinical efficacy of external fixation, delayed open reduction, and internal fixation in treating tibial plateau fracture with dislocation.Clinical data of 34 patients diagnosed with tibial plateau fracture complicated with dislocation between January 2009 and May 2015 were retrospectively analyzed. Fifteen patients in group A underwent early calcaneus traction combined with open reduction and internal fixation and 19 in group B received early external fixation combined with delayed open reduction and internal fixation. Operation time, postoperative complication, bone healing time, knee joint range of motion, initial weight-bearing time, Rasmussen tibial plateau score, and knee function score (HSS) were statistically compared between 2 groups.The mean follow-up time was 18.6 months (range: 5-24 months). The mean operation time in group A was 96 minutes, significantly longer than 71 minutes in group B (P < .05). In group A, 5 cases had postoperative complications and 1 in group B (P < .05). The mean bone healing time in group A was 6.9 months (range: 5-9 months) and 6.0 months (range: 5-8 months) in group B (P > .05). In group A, initial weight-bearing time in group A was (14.0 ± 3.6) weeks, significantly differing from (12.9 ± 2.8) weeks in group B (P < 0.05). In group A, the mean knee joint range of motion was 122° (range: 95°-150°) and 135° (range: 100°-160°) in group B (P > 0.05). Rasmussen tibial plateau score in group A was slightly lower than that in group B (P > .05). The excellent rate of knee joint function in group A was 80% and 84.21% in group B (P > .05).External fixation combined with delayed open reduction and internal fixation is a safer and more efficacious therapy of tibial plateau fracture complicated with dislocation compared with early calcaneus traction and open reduction and internal fixation.

  12. Biomechanical Effects of Posterior Condylar Offset and Posterior Tibial Slope on Quadriceps Force and Joint Contact Forces in Posterior-Stabilized Total Knee Arthroplasty.

    PubMed

    Kang, Kyoung-Tak; Koh, Yong-Gon; Son, Juhyun; Kwon, Oh-Ryong; Lee, Jun-Sang; Kwon, Sae Kwang

    2017-01-01

    This study aimed to determine the biomechanical effect of the posterior condylar offset (PCO) and posterior tibial slope (PTS) in posterior-stabilized (PS) fixed-bearing total knee arthroplasty (TKA). We developed ±1, ±2, and ±3 mm PCO models in the posterior direction and -3°, 0°, 3°, and 6° PTS models using a previously validated FE model. The influence of changes in the PCO and PTS on the biomechanical effects under deep-knee-bend loading was investigated. The contact stress on the PE insert increased by 14% and decreased by 7% on average as the PCO increased and decreased, respectively, compared to the neutral position. In addition, the contact stress on post in PE insert increased by 18% on average as PTS increased from -3° to 6°. However, the contact stress on the patellar button decreased by 11% on average as PTS increased from -3° to 6° in all different PCO cases. The quadriceps force decreased by 14% as PTS increased from -3° to 6° in all PCO models. The same trend was found in patellar tendon force. Changes in PCO had adverse biomechanical effects whereas PTS increase had positive biomechanical effects. However, excessive PTS should be avoided to prevent knee instability and subsequent failure.

  13. ACL Fibers Inserting on the Lateral Intercondylar Ridge Carry the Greatest Loads - Are Modern Anatomic Femoral Tunnel Positions Too Low?

    PubMed Central

    Nawabi, Danyal H.; Imhauser, Carl; Tucker, Scott; Nguyen, Joseph; Wickiewicz, Thomas L.; Pearle, Andrew

    2014-01-01

    a flexion path of 0 to 90°. Results: Under an anterior tibial load at 30° flexion, the direct insertion carried 83.9% of the total ACL load compared to 16.1% in the indirect insertion (p<0.001). The direct insertion also carried more load at 90° flexion (95.2% vs 4.8%; p<0.001). Under a combined rotatory load at 15° flexion, the direct insertion carried 84.2% of the total ACL load compared to 15.8% in the indirect insertion (p<0.001). A virtual ACL graft placed at the AM position in the direct insertion demonstrated the best strain behaviour with a mean 10.9% change in length. This value was significantly lower (p<0.001) than the isometry at all 3 tunnel positions in the indirect insertion (AM = 18.5%; C = 24.9%; PL = 30.9%). Conclusion: Fibers in the direct insertion of the ACL carry more load than fibers in the indirect insertion. Virtual ACL grafts placed in the ‘higher’ direct location are more isometric than in the ‘lower’ indirect location during range of motion testing. Clinical Relevance: ‘Low’ ACL grafts in the indirect ACL insertion, resulting from AM portal drilling techniques, may experience higher loads in-vivo due to unfavorable biomechanics. With the current shift towards anatomic ACL reconstruction, it may be beneficial to create a ‘higher’ femoral tunnel within the direct insertion at the lateral intercondylar ridge. This position remains anatomical but may also be biomechanically favorable.

  14. All-polyethylene tibial components in distal femur limb-salvage surgery: a finite element analysis based on promising clinical outcomes.

    PubMed

    Tang, Fan; Zhou, Yong; Zhang, Wenli; Min, Li; Shi, Rui; Luo, Yi; Duan, Hong; Tu, Chongqi

    2017-04-04

    Whether all-polyethylene tibial (APT) components are beneficial to patients who received distal femur limb-salvage surgery lacks high-quality clinical follow-up and mechanical evidence. This study aimed to investigate the biomechanics of the distal femur reconstructed with APT tumor knee prostheses using finite element (FE) analysis based on our previous, promising clinical outcome. Three-dimensional FE models that use APT and metal-backed tibial (MBT) prostheses to reconstruct distal femoral bone defects were developed and input into the Abaqus FEA software version 6.10.1. Mesh refinement tests and gait simulation with a single foot both in the upright and 15°-flexion positions with mechanical loading were conducted. Stress distribution analysis was compared between APT and MBT at the two static positions. For both prosthesis types, the stress was concentrated on the junction of the stem and shaft, and the maximum stress in the femoral axis base was more than 100 Mpa. The stress on the tibial surface was relatively distributed, which was 1-19 MPa. The stress on the tibial bone-cement layer of the APT prosthesis was approximately 20 times higher than that on the MBT prosthesis in the same region. The stress on the proximal tibial cancellous bone and cortical bone of the APT prosthesis was 3-5 times greater than that of the MBT prosthesis, and it was more distributed. Although the stress of bone-cement around the APT component is relatively high, the stress was better distributed at the polyethylene-cement-bone interface in APT than in MBT prosthesis, which effectively protects the proximal tibia in distal femur tumor knee prosthesis replacement. These results should be considered when selecting the appropriate tibial component for a patient, especially under the foreseeable conditions of osteoporosis.

  15. Relationship between the tibial mechanical axis and bony anatomical landmarks of the calf and foot as measured on radiographs obtained with a new laser-calibrated position.

    PubMed

    He, Peiheng; Zhu, Qi; Zhang, Zhaohui; Zou, Xuenong; Xu, Dongliang

    2013-01-01

    To investigate relationship between the tibial mechanical axis and bony landmarks of the calf and foot by developing a new laser-calibrated position for radiography of the lower limb. A total of 120 volunteers were randomly divided into two groups. All subjects were marked with skin projection of the hypothetical axis of the calf on the frontal and sagittal planes. Radiographs of weight-bearing full-length lower-limb were obtained by the laser-calibrated positioning in the experimental group, and by the use of conventional technique in the control group. To consider the rotation of the calf, radiological features of the knee and ankle were investigated. The relationship between the tibial mechanical axis and the bony landmarks of the calf and foot were also measured. Anteroposterior view depicted a tangential projection on the superior/inferior tibiofibular syndesmosis and between lateral malleolus and talus in ankle mortise in the experimental group. Bony overlap on the superior/inferior tibiofibular syndesmosis and between lateral malleolus and talus was seen in control group. On the tangential projection, it also presented a clear wheel-like contour of the medial femoral condyle, but a partial overlap between medial femoral condyle and tibial plateau. The femoral joint angle between the connecting line at the lowest point of the medial and lateral femoral condyles and the tibial mechanical axis was 83.6° ± 2.49° in the experimental group and 85.3° ± 2.18° in the control group (P < 0.001). The tibial tubercle-axis distance from the center of the medial and middle one-third of the tibial tubercle to the tibial mechanical axis was 1.5 mm in the experimental group and 3.7 mm in the control group (P < 0.05). The malleoli-axis distance from the midpoint of the bimalleolar line joining the tips of the medial and lateral malleoli to the tibial mechanical axis was 1.9 mm in the experimental group and 6.9 mm in the control group (P < 0.001). Lateral view showed no

  16. Aetiology and mechanisms of injury in medial tibial stress syndrome: Current and future developments

    PubMed Central

    Franklyn, Melanie; Oakes, Barry

    2015-01-01

    Medial tibial stress syndrome (MTSS) is a debilitating overuse injury of the tibia sustained by individuals who perform recurrent impact exercise such as athletes and military recruits. Characterised by diffuse tibial anteromedial or posteromedial surface subcutaneous periostitis, in most cases it is also an injury involving underlying cortical bone microtrauma, although it is not clear if the soft tissue or cortical bone reaction occurs first. Nuclear bone scans and magnetic resonance imaging (MRI) can both be used for the diagnosis of MTSS, but the patient’s history and clinical symptoms need to be considered in conjunction with the imaging findings for a correct interpretation of the results, as both imaging modalities have demonstrated positive findings in the absence of injury. However, MRI is rapidly becoming the preferred imaging modality for the diagnosis of bone stress injuries. It can also be used for the early diagnosis of MTSS, as the developing periosteal oedema can be identified. Retrospective studies have demonstrated that MTSS patients have lower bone mineral density (BMD) at the injury site than exercising controls, and preliminary data indicates the BMD is lower in MTSS subjects than tibial stress fracture (TSF) subjects. The values of a number of tibial geometric parameters such as cross-sectional area and section modulus are also lower in MTSS subjects than exercising controls, but not as low as the values in TSF subjects. Thus, the balance between BMD and cortical bone geometry may predict an individual's likelihood of developing MTSS. However, prospective longitudinal studies are needed to determine how these factors alter during the development of the injury and to find the detailed structural cause, which is still unknown. Finite element analysis has recently been used to examine the mechanisms involved in tibial stress injuries and offer a promising future tool to understand the mechanisms involved in MTSS. Contemporary accurate diagnosis

  17. Aetiology and mechanisms of injury in medial tibial stress syndrome: Current and future developments.

    PubMed

    Franklyn, Melanie; Oakes, Barry

    2015-09-18

    Medial tibial stress syndrome (MTSS) is a debilitating overuse injury of the tibia sustained by individuals who perform recurrent impact exercise such as athletes and military recruits. Characterised by diffuse tibial anteromedial or posteromedial surface subcutaneous periostitis, in most cases it is also an injury involving underlying cortical bone microtrauma, although it is not clear if the soft tissue or cortical bone reaction occurs first. Nuclear bone scans and magnetic resonance imaging (MRI) can both be used for the diagnosis of MTSS, but the patient's history and clinical symptoms need to be considered in conjunction with the imaging findings for a correct interpretation of the results, as both imaging modalities have demonstrated positive findings in the absence of injury. However, MRI is rapidly becoming the preferred imaging modality for the diagnosis of bone stress injuries. It can also be used for the early diagnosis of MTSS, as the developing periosteal oedema can be identified. Retrospective studies have demonstrated that MTSS patients have lower bone mineral density (BMD) at the injury site than exercising controls, and preliminary data indicates the BMD is lower in MTSS subjects than tibial stress fracture (TSF) subjects. The values of a number of tibial geometric parameters such as cross-sectional area and section modulus are also lower in MTSS subjects than exercising controls, but not as low as the values in TSF subjects. Thus, the balance between BMD and cortical bone geometry may predict an individual's likelihood of developing MTSS. However, prospective longitudinal studies are needed to determine how these factors alter during the development of the injury and to find the detailed structural cause, which is still unknown. Finite element analysis has recently been used to examine the mechanisms involved in tibial stress injuries and offer a promising future tool to understand the mechanisms involved in MTSS. Contemporary accurate diagnosis

  18. Effects of packaging environments on free radicals in gamma-irradiated UHMWPE resin powder blend with vitamin E.

    PubMed

    Ridley, M D; Jahan, M S

    2009-03-15

    Ultra-high molecular weight polyethylene (UHMWPE) powder (GUR 1020) was blended with high concentration (20%) of vitamin E (alpha-Tocopherol (alpha-T)) for direct detection of alpha-T radicals in presence of PE radicals. Samples were gamma-irradiated in sealed packages filled with N(2), or in open air. Free radicals were measured in open air environment for 71 days using electron spin resonance (ESR) technique. When irradiated in air, both alpha-T and alpha-T-resin produced identical ESR signals characteristics of tochopheroxyl radicals (alpha-T-O(*)), suggesting that PE radicals are quenched by alpha-T. There was no indication of growth of oxygen-induced radicals (OIR) either. However, when alpha-T-resin was irradiated in N(2), presence of both PE and alpha-T radicals were evident in the ESR spectra. And, OIR were produced by the same samples when they were subsequently exposed to air (for 71 days). Oxidation data recorded 85 days after postirradiation aging in air using Fourier transform infra-red (FTIR) spectroscopy, however, did not show any measurable difference between samples irradiated in N(2) and air.

  19. Paediatric tibial shaft fractures treated by open reduction and stabilization with monolateral external fixation

    PubMed Central

    Simon, A.-L.; Apostolou, N.; Vidal, C.; Ferrero, E.; Mazda, K.; Ilharreborde, B.

    2018-01-01

    Abstract Purpose Elastic stable intramedullary nailing is increasingly used for surgical treatment of tibial shaft fractures, but frequently requires immobilization and delayed full weight-bearing. Therefore, external fixation remains interesting. The aim was to report clinico-radiological outcomes of monolateral external fixation for displaced and unstable tibial shaft fractures in children. Methods All tibial fractures consecutively treated by monolateral external fixation between 2008 and 2013 were followed. Inclusion criteria included skeletal immaturity and closed and open Gustilo I fractures caused by a direct impact. Patients were seen until two years postoperatively. Demographics, mechanism of injury, surgical data and complications were recorded. Anteroposterior and lateral side radiographs were performed at each visit. Full-limb 3D reconstructions using biplanar stereroradiography was performed for final limb length and alignment measures. Results A total of 45 patients (mean age 9.7 years ± 0.5) were included. In all, 17 were Gustilo I fractures, with no difference between open and closed fractures for any data. Mean time to full weight bearing was 18.2 days ± 0.7. After 15 days, 39 patients returned to school. Hardware removal (mean time to union 15.6 weeks ± 0.8) was performed during consultation under analgesic gas. There were no cases of nonunion. No fracture healed with > 10° of angulation (mean 5.1° ± 0.4°). Leg-length discrepancy > 10 mm was found for six patients. Conclusions This procedure can be a safe and simple surgical treatment for children with tibial shaft fractures. Few complications and early return to school were reported, with the limitations of non-comparative study. Level of Evidence IV PMID:29456750

  20. Do physical examination and CT-scan measures of femoral neck anteversion and tibial torsion relate to each other?

    PubMed

    Sangeux, Morgan; Mahy, Jessica; Graham, H Kerr

    2014-01-01

    Informed clinical decision making for femoral and/or tibial de-rotation osteotomies requires accurate measurement of patient function through gait analysis and anatomy through physical examination of bony torsions. Validity of gait analysis has been extensively studied; however, controversy remains regarding the accuracy of physical examination measurements of femoral and tibial torsion. Comparison between CT-scans and physical examination measurements of femoral neck anteversion (FNA) and external tibial torsion (ETT) were retrospectively obtained for 98 (FNA) and 64 (ETT) patients who attended a tertiary hospital for instrumented gait analysis between 2007 and 2010. The physical examination methods studied for femoral neck anteversion were the trochanteric prominence angle test (TPAT) and the maximum hip rotation arc midpoint (Arc midpoint) and for external tibial torsion the transmalleolar axis (TMA). Results showed that all physical examination measurements statistically differed to the CT-scans (bias(standard deviation): -2(14) for TPAT, -10(12) for Arc midpoint and -16(9) for TMA). Bland and Altman plots showed that method disagreements increased with increasing bony torsions in all cases but notably for TPAT. Regression analysis showed that only TMA and CT-scan measurement of external tibial torsion demonstrated good (R(2)=57%) correlation. Correlations for both TPAT (R(2)=14%) and Arc midpoint (R(2)=39%) with CT-scan measurements of FNA were limited. We conclude that physical examination should be considered as screening techniques rather than definitive measurement methods for FNA and ETT. Further research is required to develop more accurate measurement methods to accompany instrumented gait analysis. Copyright © 2013. Published by Elsevier B.V.

  1. Influence of Medial Collateral Ligament Release for Internal Rotation of Tibia in Posterior-Stabilized Total Knee Arthroplasty: A Cadaveric Study.

    PubMed

    Wada, Keizo; Hamada, Daisuke; Tamaki, Shunsuke; Higashino, Kosaku; Fukui, Yoshihiro; Sairyo, Koichi

    2017-01-01

    Previous studies suggested that changes in kinematics in total knee arthroplasty (TKA) affected satisfaction level. The aim of this cadaveric study was to evaluate the effect of medial collateral ligament (MCL) release by multiple needle puncture on knee rotational kinematics in posterior-stabilized TKA. Six fresh, frozen cadaveric knees were included in this study. All TKA procedures were performed with an image-free navigation system using a 10-mm polyethylene insert. Tibial internal rotation was assessed to evaluate intraoperative knee kinematics. Multiple needle puncturing was performed 5, 10, and 15 times for the hard portion of the MCL at 90° knee flexion. Kinematic analysis was performed after every 5 punctures. After performing 15 punctures, a 14-mm polyethylene insert was inserted, and kinematic analysis was performed. The tibial internal rotation angle at maximum knee flexion without multiple needle puncturing was significantly larger (9.42°) than that after 15 punctures (3°). Negative correlation (Pearson r = -0.715, P < .001) between tibial internal rotation angle at maximum knee flexion and frequency of puncture was observed. The tibial internal rotation angle with a 14-mm insert was significantly larger (7.25°) compared with the angle after 15 punctures. Tibial internal rotation during knee flexion was reduced by extensive MCL release using multiple needle puncturing and was recovered by increasing of medial tightness. From the point of view of knee kinematics, medial tightness should be allowed to maintain the internal rotation angle of the tibia during knee flexion which might lead to patient satisfaction. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Significant effect of the posterior tibial slope and medial/lateral ligament balance on knee flexion in total knee arthroplasty.

    PubMed

    Fujimoto, Eisaku; Sasashige, Yoshiaki; Masuda, Yasuji; Hisatome, Takashi; Eguchi, Akio; Masuda, Tetsuo; Sawa, Mikiya; Nagata, Yoshinori

    2013-12-01

    The intra-operative femorotibial joint gap and ligament balance, the predictors affecting these gaps and their balances, as well as the postoperative knee flexion, were examined. These factors were assessed radiographically after a posterior cruciate-retaining total knee arthroplasty (TKA). The posterior condylar offset and posterior tibial slope have been reported as the most important intra-operative factors affecting cruciate-retaining-type TKAs. The joint gap and balance have not been investigated in assessments of the posterior condylar offset and the posterior tibial slope. The femorotibial gap and medial/lateral ligament balance were measured with an offset-type tensor. The femorotibial gaps were measured at 0°, 45°, 90° and 135° of knee flexion, and various gap changes were calculated at 0°-90° and 0°-135°. Cruciate-retaining-type arthroplasties were performed in 98 knees with varus osteoarthritis. The 0°-90° femorotibial gap change was strongly affected by the posterior condylar offset value (postoperative posterior condylar offset subtracted by the preoperative posterior condylar offset). The 0°-135° femorotibial gap change was significantly correlated with the posterior tibial slope and the 135° medial/lateral ligament balance. The postoperative flexion angle was positively correlated with the preoperative flexion angle, γ angle and the posterior tibial slope. Multiple-regression analysis demonstrated that the preoperative flexion angle, γ angle, posterior tibial slope and 90° medial/lateral ligament balance were significant independent factors for the postoperative knee flexion angle. The flexion angle change (postoperative flexion angle subtracted by the preoperative flexion angle) was also strongly correlated with the preoperative flexion angle, posterior tibial slope and 90° medial/lateral ligament balance. The postoperative flexion angle is affected by multiple factors, especially in cruciate-retaining-type TKAs. However, it is

  3. Effect of tibial positioning on the diagnosis of posterolateral rotatory instability in the posterior cruciate ligament-deficient knee.

    PubMed

    Strauss, Eric J; Ishak, Charbel; Inzerillo, Christopher; Walsh, Michael; Yildirim, Gokce; Walker, Peter; Jazrawi, Laith; Rosen, Jeffrey

    2007-08-01

    To determine whether positioning of the tibia affects the degree of tibial external rotation seen during a dial test in the posterior cruciate ligament (PCL)-posterolateral corner (PLC)-deficient knee. Laboratory investigation. Biomechanics laboratory. An anterior force applied to the tibia in the combined PCL-PLC-deficient knee will yield increased tibial external rotation during a dial test. The degree of tibial external rotation was measured with 5 Nm of external rotation torque applied to the tibia at both 30 degrees and 90 degrees of knee flexion. Before the torque was applied, an anterior force, a posterior force, or neutral (normal, reduced control) force was applied to the tibia. External rotation measurements were repeated after sequential sectioning of the PCL, the posterolateral structures and the fibular collateral ligament (FCL). Baseline testing of the intact specimens demonstrated a mean external rotation of 18.6 degrees with the knee flexed to 30 degrees (range 16.1-21.0 degrees ), and a mean external rotation of 17.3 degrees with the knee flexed to 90 degrees (range 13.8-20.0 degrees ). Sequential sectioning of the PCL, popliteus and popliteofibular ligament, and the FCL led to a significant increase in tibial external rotation compared with the intact knee for all testing scenarios. After sectioning of the popliteus and popliteofibular ligament, the application of an anterior force during testing led to a mean tibial external rotation that was 5 degrees greater than during testing in the neutral position and 7.5 degrees greater than during testing with a posterior force. In the PCL, popliteus/popliteofibular ligament and FCL-deficient knee, external rotation was 9 degrees and 12 degrees greater with the application of an anterior force during testing compared with neutral positioning and the application of a posterior force, respectively. An anterior force applied to the tibia during the dial test in a combined PCL-PLC-injured knee increased the

  4. Tibial avulsion fracture of the posterior root of the medial meniscus in a skeletally-immature child - a case report.

    PubMed

    Matava, Matthew J; Kim, Young-Mo

    2011-01-01

    It has been theorized that a traumatic tibial avulsion fracture of the posterior root of the medial meniscus (MM) is the cause of the so-called meniscus ossicle (MO). We report the delayed appearance of a tibial avulsion fracture of the posterior root of the MM after a valgus, twisting injury in a 12-year-old boy with open physes. Magnetic resonance imaging (MRI) scans performed 3 days after the injury did not demonstrate a definitive tibial avulsion fracture of the posterior root of the MM; whereas, a repeat MRI for 3 months post-injury did. Medial extrusion of the MM was also noted on the 3 month MRI. Arthroscopic reattachment of the avulsed posterior root of the MM using a trans-physeal nonabsorbable suture tied over a proximal tibia staple was performed. Follow-up MRI at 6 months postoperatively demonstrated healing of the tibial avulsion fracture of the posterior root of the MM in an anatomic position. The patient had a complete resolution of symptoms and there was no angular deformity or limb-length discrepancy at 2 years postoperatively. To our knowledge, this is the first report describing a tibial avulsion fracture of the posterior root of the MM in a skeletally-immature patient successfully treated by a trans-physeal arthroscopic suture. This case also illustrates the development of the MO of the posterior root of the MM. Copyright © 2010 Elsevier B.V. All rights reserved.

  5. Prevention of arthrofibrosis after arthroscopic screw fixation of tibial spine fracture in children and adolescents.

    PubMed

    Parikh, Shital N; Myer, David; Eismann, Emily A

    2014-01-01

    Arthrofibrosis is a major complication of tibial spine fracture treatment in children, potentially resulting in knee pain, quadriceps weakness, altered gait, decreased function, inability to return to sports, and long-term osteoarthritis. Thus, prevention rather than treatment of arthrofibrosis is desirable. The purpose of this study was to evaluate an aggressive postoperative rehabilitation and early intervention approach to prevent permanent arthrofibrosis after tibial spine fracture treatment and to compare epiphyseal and transphyseal screws for fixation. A consecutive series of 24 patients younger than age 18 with displaced type II and III tibial spine fractures who underwent arthroscopic reduction and screw fixation between 2006 and 2011 were retrospectively reviewed. Final range of motion was compared between patients with epiphyseal (n=12) and transphyseal (n=9) screws. One-third (4 of 12) of patients with epiphyseal screws underwent arthroscopic debridement and screw removal approximately 3 months postoperatively; 3 patients lacked 5° to 15° of extension, 1 experienced pain with extension, and 1 had radiographic evidence of screw pullout, loss of reduction, and resultant malunion. In the transphyseal screw group, 3 patients had 10° loss of extension, and all corrected after arthroscopic debridement and screw removal. The two groups did not significantly differ in time to hardware removal or return to sports or final range of motion. No growth disturbances were identified in patients after transphyseal screw removal. An aggressive approach of postoperative rehabilitation and early intervention after arthroscopic reduction and screw fixation of tibial spine fractures in children was successful in preventing permanent arthrofibrosis.

  6. Rare case of tibial hemimelia, preaxial polydactyly, and club foot

    PubMed Central

    Granite, Guinevere; Herzenberg, John E; Wade, Ronald

    2016-01-01

    A seven-month old female presented with left tibial hemimelia (or congenital tibial aplasia; Weber type VIIb, Jones et al type 1a), seven-toed preaxial polydactyly, and severe club foot (congenital talipes equinovarus). Definitive amputation surgery disarticulated the lower limb at the knee. This case report describes the anatomical findings of a systematic post-amputation examination of the lower limb’s superficial dissection, X-rays, and computed tomography (CT) scans. From the X-rays and CT scans, we found curved and overlapping preaxial supernumerary toes, hypoplastic first metatarsal, lack of middle and distal phalanges in one supernumerary toe, three tarsal bones, hypoplastic middle phalanx and no distal phalanx for fourth toe, and no middle or distal phalanges for fifth toe. The fibula articulated with the anteromedial calcaneus and the tibia was completely absent. We identified numerous muscles and nerves in the superficial dissection that are described in the results section of the case report. Due to the rarity of this combination of anatomical findings, descriptions of such cases are very infrequent in the literature. PMID:28035313

  7. Rare case of tibial hemimelia, preaxial polydactyly, and club foot.

    PubMed

    Granite, Guinevere; Herzenberg, John E; Wade, Ronald

    2016-12-16

    A seven-month old female presented with left tibial hemimelia (or congenital tibial aplasia; Weber type VIIb, Jones et al type 1a), seven-toed preaxial polydactyly, and severe club foot (congenital talipes equinovarus). Definitive amputation surgery disarticulated the lower limb at the knee. This case report describes the anatomical findings of a systematic post-amputation examination of the lower limb's superficial dissection, X-rays, and computed tomography (CT) scans. From the X-rays and CT scans, we found curved and overlapping preaxial supernumerary toes, hypoplastic first metatarsal, lack of middle and distal phalanges in one supernumerary toe, three tarsal bones, hypoplastic middle phalanx and no distal phalanx for fourth toe, and no middle or distal phalanges for fifth toe. The fibula articulated with the anteromedial calcaneus and the tibia was completely absent. We identified numerous muscles and nerves in the superficial dissection that are described in the results section of the case report. Due to the rarity of this combination of anatomical findings, descriptions of such cases are very infrequent in the literature.

  8. Economics of All-Polyethylene Versus Metal-Backed Tibial Prosthesis Designs.

    PubMed

    Chambers, Monique C; El-Othmani, Mouhanad M; Sayeed, Zain; Anoushiravani, Afshin; Schnur, Anne-Kathrin; Mihalko, William M; Saleh, Khaled J

    2016-05-01

    With the large number of total knee arthroplasties being performed and expectations that these numbers will be on the rise over the coming decades, efforts to provide cost-efficient care are of greater interest. The preferred design of knee arthroplasty implants has changed over time, with the original all-polyethylene tibial (APT) design being replaced by metal-backed tibial (MBT) components, as well as more recent considerations of newer APT designs. Modern APT components have been shown to have similar or superior outcomes than MBT components. Despite their limitations, APT components can be used to reduce the economic burden to the provider, medical institution, and health care system as a whole. There is a paucity of evidence-based literature directly comparing the cost associated with APT and MBT components. The purpose of this report is to review the literature to assess the available data regarding direct and indirect costs of both designs so that orthopedic surgeons can account for economic differences in everyday practice. [Orthopedics. 2016; 39(3):S61-S66.]. Copyright 2016, SLACK Incorporated.

  9. Analysis of anatomic periarticular tibial plate fit on normal adults.

    PubMed

    Goyal, Kanu S; Skalak, Anthony S; Marcus, Randall E; Vallier, Heather A; Cooperman, Daniel R

    2007-08-01

    Implant manufacturers are producing anatomically contoured periarticular plates to improve the treatment of proximal tibia fractures. We assessed the accuracy of the designation anatomic. We applied eight-hole medial and lateral anatomically contoured periarticular plates to 101 cadaveric tibiae. The tibiae and the plate fits were mapped, quantified, and analyzed using a MicroScribe G2LX digitizer, Rhinoceros software, and MATLAB software. By corresponding the clinical appearance of good fit with our digital findings, we created numerical criteria for plate fit in three planes: coronal (volume of free space between the plate and bone), sagittal (alignment with the tibial plateau and shaft), and axial (match in curvature between the proximal horizontal part of the plate and the tibial plateau). An anatomic fit should mirror the shape of the tibia in all three planes, and only four medial and four lateral plate fits qualified. Recognizing and understanding the substantial variations in fit that exist between anatomically contoured plates and the tibia may help lead to a more stable fixation and prevent malreduction of the fracture and/or soft tissue impingement.

  10. Management of Gustilo Anderson III B open tibial fractures by primary fascio-septo-cutaneous local flap and primary fixation: The 'fix and shift' technique.

    PubMed

    Ramasamy, P R

    2017-01-01

    Open fractures of tibia have posed great difficulty in managing both the soft tissue and the skeletal components of the injured limb. Gustilo Anderson III B open tibial fractures are more difficult to manage than I, II, and III A fractures. Stable skeletal fixation with immediate soft tissue cover has been the key to the successful outcome in treating open tibial fractures, in particular, Gustilo Anderson III B types. If the length of the open wound is larger and if the exposed surface of tibial fracture and tibial shaft is greater, then the management becomes still more difficult. Thirty six Gustilo Anderson III B open tibial fractures managed between June 2002 and December 2013 with "fix and shift" technique were retrospectively reviewed. All the 36 patients managed by this technique had open wounds measuring >5 cm (post debridement). Under fix and shift technique, stable fixation involved primary external fixator application or primary intramedullary nailing of the tibial fracture and immediate soft tissue cover involved septocutaneous shift, i.e., shifting of fasciocutaneous segments based on septocutaneous perforators. Primary fracture union rate was 50% and reoperation rate (bone stimulating procedures) was 50%. Overall fracture union rate was 100%. The rate of malunion was 14% and deep infection was 16%. Failure of septocutaneous shift was 2.7%. There was no incidence of amputation. Management of Gustilo Anderson III B open tibial fractures with "fix and shift" technique has resulted in better outcome in terms of skeletal factors (primary fracture union, overall union, and time for union and malunion) and soft tissue factors (wound healing, flap failure, access to secondary procedures, and esthetic appearance) when compared to standard methods adopted earlier. Hence, "fix and shift" could be recommended as one of the treatment modalities for open III B tibial fractures.

  11. Motion at the Tibial and Polyethylene Component Interface in a Mobile-Bearing Total Ankle Replacement.

    PubMed

    Lundeen, Gregory A; Clanton, Thomas O; Dunaway, Linda J; Lu, Minggen

    2016-08-01

    Normal biomechanics of the ankle joint includes sagittal as well as axial rotation. Current understanding of mobile-bearing motion at the tibial-polyethylene interface in total ankle arthroplasty (TAA) is limited to anterior-posterior (AP) motion of the polyethylene component. The purpose of our study was to define the motion of the polyethylene component in relation to the tibial component in a mobile-bearing TAA in both the sagittal and axial planes in postoperative patients. Patients who were a minimum of 12 months postoperative from a third-generation mobile-bearing TAA were identified. AP images were saved at maximum internal and external rotation, and the lateral images were saved in maximum plantarflexion and dorsiflexion. Sagittal range of motion and AP translation of the polyethylene component were measured from the lateral images. Axial rotation was determined by measuring the relative position of the 2 wires within the polyethylene component on AP internal and external rotation imaging. This relationship was compared to a table developed from fluoroscopic images taken at standardized degrees of axial rotation of a nonimplanted polyethylene with the associated length relationship of the 2 imbedded wires. Sixteen patients were included in this investigation, 9 (56%) were male and average age was 68 (range, 49-80) years. Time from surgery averaged 25 (range, 12-38) months. Total sagittal range of motion averaged 23±9 (range, 9-33) degrees. Axial motion for total internal and external rotation of the polyethylene component on the tibial component averaged 6±5 (range, 0-18) degrees. AP translation of the polyethylene component relative to the tibial component averaged 1±1 (range, 0-3) mm. There was no relationship between axial rotation or AP translation of the polyethylene component and ankle joint range of motion (P > .05). To our knowledge, this is the first investigation to measure axial and sagittal motion of the polyethylene component at the tibial

  12. Complex tibial fracture outcomes following treatment with low-intensity pulsed ultrasound.

    PubMed

    Leung, Kwok-Sui; Lee, Wing-Sze; Tsui, Hon-For; Liu, Paul Po-Lung; Cheung, Wing-Hoi

    2004-03-01

    A clinical study was conducted to investigate the effect of low-intensity pulsed ultrasound (US) stimulation (LIPUS) on the healing of complex tibial fractures. Thirty complex tibial fractures were randomly assigned to the treatment with LIPUS (n = 16) or by a dummy machine (sham-exposed: n = 14). The fractures were immobilized by either internal or external fixations according to the clinical indications. LIPUS was given 20 min/day for 90 days. Fracture healing was monitored by clinical, radiological, densitometric and biochemical assessments. The LIPUS-treated group showed statistically significantly better healing, as demonstrated by all assessments. Complications were minimal in the LIPUS group. There were two cases of delayed union, with one in each group. There were two cases of infection in the control group. The delayed-union cases were subsequently treated by LIPUS and the infection cases were treated with standard protocol. Fracture healing in these patients was again treated by LIPUS.

  13. Defining the Lower Limit of a "Critical Bone Defect" in Open Diaphyseal Tibial Fractures.

    PubMed

    Haines, Nikkole M; Lack, William D; Seymour, Rachel B; Bosse, Michael J

    2016-05-01

    To determine healing outcomes of open diaphyseal tibial shaft fractures treated with reamed intramedullary nailing (IMN) with a bone gap of 10-50 mm on ≥50% of the cortical circumference and to better define a "critical bone defect" based on healing outcome. Retrospective cohort study. Forty patients, age 18-65, with open diaphyseal tibial fractures with a bone gap of 10-50 mm on ≥50% of the circumference as measured on standard anteroposterior and lateral postoperative radiographs treated with IMN. IMN of an open diaphyseal tibial fracture with a bone gap. Level-1 trauma center. Healing outcomes, union or nonunion. Forty patients were analyzed. Twenty-one (52.5%) went on to nonunion and nineteen (47.5%) achieved union. Radiographic apparent bone gap (RABG) and infection were the only 2 covariates predicting nonunion outcome (P = 0.046 for infection). The RABG was determined by measuring the bone gap on each cortex and averaging over 4 cortices. Fractures achieving union had a RABG of 12 ± 1 mm versus 20 ± 2 mm in those going on to nonunion (P < 0.01). This remained significant when patients with infection were removed. Receiver operator characteristic analysis demonstrated that RABG was predictive of outcome (area under the curve of 0.79). A RABG of 25 mm was the statistically optimal threshold for prediction of healing outcome. Patients with open diaphyseal tibial fractures treated with IMN and a <25 mm RABG have a reasonable probability of achieving union without additional intervention, whereas those with larger gaps have a higher probability of nonunion. Research investigating interventions for RABGs should use a predictive threshold for defining a critical bone defect that is associated with greater than 50% risk of nonunion without supplementary treatment. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

  14. Newly designed anterolateral and posterolateral locking anatomic plates for lateral tibial plateau fractures: a finite element study.

    PubMed

    Chen, Pengbo; Lu, Hua; Shen, Hao; Wang, Wei; Ni, Binbin; Chen, Jishizhan

    2017-02-23

    Lateral column tibial plateau fracture fixation with a locking screw plate has higher mechanical stability than other fixation methods. The objectives of the present study were to introduce two newly designed locking anatomic plates for lateral tibial plateau fracture and to demonstrate their characteristics of the fixation complexes under the axial loads. Three different 3D finite element models of the lateral tibial plateau fracture with the bone plates were created. Various axial forces (100, 500, 1000, and 1500 N) were applied to simulate the axial compressive load on an adult knee during daily life. The equivalent maps of displacement and stress were output, and relative displacement was calculated along the fracture lines. The displacement and stresses in the fixation complexes increased with the axial force. The equivalent displacement or stress map of each fixation under different axial forces showed similar distributing characteristics. The motion characteristics of the three models differed, and the max-shear stress of trabecula increased with the axial load. These two novel plates could fix lateral tibial plateau fractures involving anterolateral and posterolateral fragments. Motions after open reduction and stable internal fixation should be advised to decrease the risk of trabecular microfracture. The relative displacement of the posterolateral fragments is different when using anterolateral plate and posterolateral plate, which should be considered in choosing the implants for different posterolateral plateau fractures.

  15. The Effect of Sagittal Plane Deformities after Tibial Plateau Fractures to Functions and Instability of Knee Joint.

    PubMed

    Erdil, M; Yildiz, F; Kuyucu, E; Sayar, Ş; Polat, G; Ceylan, H H; Koçyiğit, F

    2016-01-01

    The objective of this study is to evaluate the effect of posterior tibial slope after fracture healing on antero-posterior knee laxity, functional outcome and patient satisfaction. 126 patients who were treated for tibial plateau fractures between 2008-2013 in the orthopedics and traumatology department of our institution were evaluated for the study. Patients were treated with open reduction and internal fixation, arthroscopy assisted minimally invasive osteosynthesis or conservative treatment. Mean posterior tibial slope after the treatment was 6.91 ± 5.11 and there was no significant difference when compared to the uninvolved side 6.42 ± 4,21 (p = 0.794). Knee laxity in anterior-posterior plane was 6.14 ± 2.11 and 5.95 ± 2.25 respectively on healthy and injured side. The difference of mean laxity in anterior-posterior plane between two sides was statistically significant. In this study we found no difference in laxity between the injured and healthy knees. However Tegner score decreased significantly in patients who had greater laxity difference between the knees. We did not find significant difference between fracture type and laxity, IKDC functional scores independent of the ligamentous injury. In conclusion despite coronal alignment is taken into consideration in treatment of tibial plateau fractures, sagittal alignment is reasonably important for stability and should not be ignored.

  16. Comparison of Clinical Results and Injury Risk of Posterior Tibial Cortex Between Attune and Press Fit Condylar Sigma Knee Systems.

    PubMed

    Song, Sang Jun; Park, Cheol Hee; Liang, Hu; Kang, Se Gu; Park, Jong Jun; Bae, Dae Kyung

    2018-02-01

    We compared clinical and radiographic results after total knee arthroplasty (TKA) using Attune and Press Fit Condylar Sigma, and investigated whether use of the current prosthesis increased injury risk to the tibial cortex in Asian patients. We also assessed whether a preoperative posterior tibial slope angle (PSA) is associated with the injury when using the current prosthesis. The 300 TKAs with Attune (group A) were compared to the 300 TKAs with Press Fit Condylar Sigma (group B). Demographics were not different, except follow-up periods (24.8 vs 33.3 months, P < .001). The Western Ontario and McMaster Universities Index and range of motion were compared. A minimum distance between tibial component stem and posterior tibial cortex (mDSC) was compared. The correlation between preoperative PSA and mDSC was analyzed in group A. The postoperative Western Ontario and McMaster Universities Index and range of motion of group A were better than those of group B (17.7 vs 18.8, P = .004; 131.4° vs 129.0°, P = .008). The mDSC was shorter in group A (6.3 vs 7.0 mm, P < .001), which made up a higher proportion of the high-risk group for posterior tibial cortical injury with an mDSC of <4 mm (20.0% vs 10.7%, P = .002). A negative correlation was found between the preoperative PSA and mDSC in group A (r = -0.205, P < .001). The TKA using the current prosthesis provided more satisfactory results than the TKA using the previous prosthesis. However, the injury risk to the posterior tibial cortex increased in the knees with a large PSA when using the current prosthesis for Asian patients. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Flow-Through Free Fibula Osteocutaneous Flap in Reconstruction of Tibial Bone, Soft Tissue, and Main Artery Segmental Defects.

    PubMed

    Li, Zonghuan; Yu, Aixi; Qi, Baiwen; Pan, Zhenyu; Ding, Junhui

    2017-08-01

    The aim of this report was to present the use of flow-through free fibula osteocutaneous flap for the repair of complex tibial bone, soft tissue, and main artery segmental defects. Five patients with bone, soft tissue, and segmental anterior tibial artery defects were included. The lengths of injured tibial bones ranged from 4 to 7 cm. The sizes of impaired soft tissues were between 9 × 4 and 15 × 6 cm. The lengths of defect of anterior tibial artery segments ranged from 6 to 10 cm. Two patients had distal limb perfusion problems. Flow-through free fibula osteocutaneous flap was performed for all 5 patients. Patients were followed for 12 to 18 months. All wounds healed after 1-stage operation, and all flow-through flaps survived. The distal perfusion after vascular repair was normal in all patients. Superficial necrosis of flap edge was noted in 1 case. After the local debridement and partial thickness skin graft, the flap healed uneventfully, and the surgical operation did not increase injury to the donor site. Satisfactory bone union was achieved in all patients in 2 to 4 months postoperation. Enlargement of fibula graft was observed during follow-up from 12 to 18 months. The functions of adjacent joints were recovered, and all patients were able to walk normally. Flow-through free fibula osteocutaneous flap was shown to be an effective and efficient technique for repairing composite tibial bone, soft tissue, and main artery segmental defects. This 1-stage operation should be useful in clinical practice for the treatment of complex bone, soft tissue, and vessel defects.

  18. Load Sharing Among Collateral Ligaments, Articular Surfaces, and the Tibial Post in Constrained Condylar Knee Arthroplasty.

    PubMed

    Wang, Xiaonan; Malik, Aamer; Bartel, Donald L; Wright, Timothy M; Padgett, Douglas E

    2016-08-01

    The normal knee joint maintains stable motion during activities of daily living. After total knee arthroplasty (TKA), stability is achieved by the conformity of the bearing surfaces of the implant components, ligaments, and constraint structures incorporated in the implant design. The large, rectangular tibial post in constrained condylar knee (CCK) arthroplasty, often used in revision surgery, provides added stability, but increases susceptibility to polyethylene wear as it contacts the intercondylar box on the femoral component. We examined coronal plane stability to understand the relative contributions of the mechanisms that act to stabilize the CCK knee under varus-valgus loading, namely, load distribution between the medial and lateral condyles, contact of the tibial post with the femoral intercondylar box, and elongation of the collateral ligaments. A robot testing system was used to determine the joint stability in human cadaveric knees as described by the moment versus angular rotation behavior under varus-valgus moments at 0 deg, 30 deg, and 90 deg of flexion. The angular rotation of the CCK knee in response to the physiological moments was limited to ≤1.5 deg. The primary stabilizing mechanism was the redistribution of the contact force on the bearing surfaces. Contact between the tibial post and the femoral box provided a secondary stabilizing mechanism after lift-off of a condyle had occurred. Collateral ligaments provide limited stability because little ligament elongation occurred under such small angular rotations. Compressive loads applied across the knee joint, such as would occur with the application of muscle forces, enhanced the ability of the bearing surfaces to provide resisting internal varus-valgus moment and, thus, reduced the exposure of the tibial post to the external varus-valgus loads. Our results suggest that the CCK stability can be refined by considering both the geometry of the bearing surfaces and the contacting geometry

  19. High tibial closing wedge osteotomy for medial compartment osteoarthrosis of knee

    PubMed Central

    Tuli, SM; Kapoor, Varun

    2008-01-01

    Background: Most patients of symptomatic osteoarthrosis of knee are associated with varus malalignment that is causative or contributory to painful arthrosis. It is rational to correct the malalignment to transfer the functional load to the unaffected or less affected compartment of the knee to relieve symptoms. We report the outcome of a simple technique of high tibial osteotomy in the medial compartment osteoarthrosis of the knee. Materials and Methods: Between 1996 and 2004 we performed closing wedge osteotomy in 78 knees in 65 patients. The patients selected for osteotomy were symptomatic essentially due to medial compartment osteoarthrosis associated with moderate genu varum. Of the 19 patients who had bilateral symptomatic disease 11 opted for high tibial osteotomy of their second knee 1-3 years after the first operation. Preoperative grading of osteoarthrosis and postoperative function was assessed using Japanese Orthopaedic Association (JOA) rating scale. Results: At a minimum follow-up of 2 years (range 2-9 years) 6-10° of valgus correction at the site of osteotomy was maintained, there was significant relief of pain while walking, negotiating stairs, squatting and sitting cross-legged. Walking distance in all patients improved by two to four times their preoperative distance of 200-400 m. No patient lost any preoperative knee function. The mean JOA scoring improved from preoperative 54 (40-65) to 77 (55-85) at final follow-up. Conclusion: Closing wedge high tibial osteotomy performed by our technique can be undertaken in any setup with moderate facilities. Operation related complications are minimal and avoidable. Kirschner wire fixation is least likely to interfere with replacement surgery if it becomes necessary. PMID:19823659

  20. Tool Removes Coil-Spring Thread Inserts

    NASA Technical Reports Server (NTRS)

    Collins, Gerald J., Jr.; Swenson, Gary J.; Mcclellan, J. Scott

    1991-01-01

    Tool removes coil-spring thread inserts from threaded holes. Threads into hole, pries insert loose, grips insert, then pulls insert to thread it out of hole. Effects essentially reverse of insertion process to ease removal and avoid further damage to threaded inner surface of hole.

  1. Tension Band Plating for Chronic Anterior Tibial Stress Fractures in High-Performance Athletes.

    PubMed

    Zbeda, Robert M; Sculco, Peter K; Urch, Ekaterina Y; Lazaro, Lionel E; Borens, Olivier; Williams, Riley J; Lorich, Dean G; Wellman, David S; Helfet, David L

    2015-07-01

    Anterior tibial stress fractures are associated with high rates of delayed union and nonunion, which can be particularly devastating to a professional athlete who requires rapid return to competition. Current surgical treatment strategies include intramedullary nailing, which has satisfactory rates of fracture union but an associated risk of anterior knee pain. Anterior tension band plating is a biomechanically sound alternative treatment for these fractures. Tension band plating of chronic anterior tibial stress fractures leads to rapid healing and return to physical activity and avoids the anterior knee pain associated with intramedullary nailing. Case series; Level of evidence, 4. Between 2001 and 2013, there were 13 chronic anterior tibial stress fractures in 12 professional or collegiate athletes who underwent tension band plating after failing nonoperative management. Patient charts were retrospectively reviewed for demographics, injury history, and surgical details. Radiographs were used to assess time to osseous union. Follow-up notes and phone interviews were used to determine follow-up time, return to training time, and whether the patient was able to return to competition. Cases included 13 stress fractures in 12 patients (9 females, 3 males). Five patients were track-and-field athletes, 4 patients played basketball, 2 patients played volleyball, and 1 was a ballet dancer. Five patients were Division I collegiate athletes and 7 were professional or Olympic athletes. Average age at time of surgery was 23.6 years (range, 20-32 years). Osseous union occurred on average at 9.6 weeks (range, 5.3-16.9 weeks) after surgery. Patients returned to training on average at 11.1 weeks (range, 5.7-20 weeks). Ninety-two percent (12/13) eventually returned to preinjury competition levels. Thirty-eight percent (5/13) underwent removal of hardware for plate prominence. There was no incidence of infection or nonunion. Anterior tension band plating for chronic tibial stress

  2. Tibial Inlay Press-fit Fixation Versus Interference Screw in Posterior Cruciate Ligament Reconstruction.

    PubMed

    Ettinger, Max; Büermann, Sarah; Calliess, Tilman; Omar, Mohamed; Krettek, Christian; Hurschler, Christof; Jagodzinski, Michael; Petri, Maximilian

    2013-01-01

    Reconstruction of the posterior cruciate ligament (PCL) by a tibial press-fit fixation of the patellar tendon with an accessory bone plug is a promising approach because no foreign materials are required. Until today, there is no data about the biomechanical properties of such press-fit fixations. The aim of this study was to compare the biomechanical qualities of a bone plug tibial inlay technique with the commonly applied interference screw of patellar tendon PCL grafts. Twenty patellar tendons including a bone block were harvested from ten human cadavers. The grafts were implanted into twenty legs of adult German country pigs. In group P, the grafts were attached in a press-fit technique with accessory bone plug. In group S, the grafts were fixed with an interference screw. Each group consisted of 10 specimens. The constructs were biomechanically analyzed in cyclic loading between 60 and 250 N for 500 cycles recording elongation. Finally, ultimate failure load and failure mode were analyzed. Ultimate failure load was 598.6±36.3 N in group P and 653.7±39.8 N in group S (not significant, P>0.05). Elongation during cyclic loading between the 1(st) and the 20(th) cycle was 3.4±0.9 mm for group P and 3.1±1 mm for group S. Between the 20(th) and the 500(th) cycle, elongation was 4.2±2.3 mm in group P and 2.5±0.9 mm in group S (not significant, P>0.05). This is the first study investigating the biomechanical properties of tibial press-fit fixation of the patellar tendon with accessory bone plug in posterior cruciate ligament reconstruction. The implant-free tibial inlay technique shows equal biomechanical characteristics compared to an interference screw fixation. Further in vivo studies are desirable to compare the biological behavior and clinical relevance of this fixation device.

  3. Utility of cement injection to stabilize split-depression tibial plateau fracture by minimally invasive methods: A finite element analysis.

    PubMed

    Belaid, D; Vendeuvre, T; Bouchoucha, A; Brémand, F; Brèque, C; Rigoard, P; Germaneau, A

    2018-05-08

    Treatment for fractures of the tibial plateau is in most cases carried out by stable fixation in order to allow early mobilization. Minimally invasive technologies such as tibioplasty or stabilization by locking plate, bone augmentation and cement filling (CF) have recently been used to treat this type of fracture. The aim of this paper was to determine the mechanical behavior of the tibial plateau by numerically modeling and by quantifying the mechanical effects on the tibia mechanical properties from injury healing. A personalized Finite Element (FE) model of the tibial plateau from a clinical case has been developed to analyze stress distribution in the tibial plateau stabilized by balloon osteoplasty and to determine the influence of the cement injected. Stress analysis was performed for different stages after surgery. Just after surgery, the maximum von Mises stresses obtained for the fractured tibia treated with and without CF were 134.9 MPa and 289.9 MPa respectively on the plate. Stress distribution showed an increase of values in the trabecular bone in the treated model with locking plate and CF and stress reduction in the cortical bone in the model treated with locking plate only. The computed results of stresses or displacements of the fractured models show that the cement filling of the tibial depression fracture may increase implant stability, and decrease the loss of depression reduction, while the presence of the cement in the healed model renders the load distribution uniform. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Treatment of large posttraumatic tibial bone defects using the Ilizarov method: a subjective outcome assessment.

    PubMed

    Krappinger, Dietmar; Irenberger, Alexander; Zegg, Michael; Huber, Burkhart

    2013-06-01

    The treatment of large posttraumatic tibial bone defects using the Ilizarov method was shown to be successful in several studies. These studies, however, typically focus on the radiological and functional outcome using objective parameters only. The aim of the present study was therefore to assess the objective and subjective outcome of a consecutive series of patients with large posttraumatic tibial bone defects using the Ilizarov method. Additionally, it was our goal to assess the physical and mental stress for the patients and their relatives during the long treatment period and the general health status at final follow-up. A consecutive series of 15 patients with posttraumatic tibial bone defects of >30 mm after sustaining open tibial fractures and failure of internal fixation was included. The objective outcome was assessed at final follow-up using Paley's criteria. For the assessment of the subjective outcome, all patients were asked to evaluate their satisfaction with the function of the lower leg, the cosmetic appearance and overall outcome as well. The physical and mental stress of the treatment for the patients and the nearest relative of patients were assessed at the time of frame removal using a custom-made questionnaire. The SF-36 was used to evaluate the general health status at final follow-up. Solid bone union with stable soft tissue coverage and eradication of infection was achieved in all patients despite a high complication rate. The functional outcome at final follow-up was excellent or good in all patients. The patients' satisfaction with the overall outcome and the function of the lower extremity was high as well. The fear of amputation and complications was the major subjective burden for both the patients and their relatives. The long external fixation time is another relevant issue. The Ilizarov method is a safe option for the treatment of large posttraumatic tibial bone defects after failure of internal fixation despite the high

  5. External fixation combined with delayed internal fixation in treatment of tibial plateau fractures with dislocation

    PubMed Central

    Tao, Xingguang; Chen, Nong; Pan, Fugen; Cheng, Biao

    2017-01-01

    Abstract The aim of this study was to evaluate the clinical efficacy of external fixation, delayed open reduction, and internal fixation in treating tibial plateau fracture with dislocation. Clinical data of 34 patients diagnosed with tibial plateau fracture complicated with dislocation between January 2009 and May 2015 were retrospectively analyzed. Fifteen patients in group A underwent early calcaneus traction combined with open reduction and internal fixation and 19 in group B received early external fixation combined with delayed open reduction and internal fixation. Operation time, postoperative complication, bone healing time, knee joint range of motion, initial weight-bearing time, Rasmussen tibial plateau score, and knee function score (HSS) were statistically compared between 2 groups. The mean follow-up time was 18.6 months (range: 5–24 months). The mean operation time in group A was 96 minutes, significantly longer than 71 minutes in group B (P < .05). In group A, 5 cases had postoperative complications and 1 in group B (P < .05). The mean bone healing time in group A was 6.9 months (range: 5–9 months) and 6.0 months (range: 5–8 months) in group B (P > .05). In group A, initial weight-bearing time in group A was (14.0 ± 3.6) weeks, significantly differing from (12.9 ± 2.8) weeks in group B (P < 0.05). In group A, the mean knee joint range of motion was 122° (range: 95°–150°) and 135° (range: 100°–160°) in group B (P > 0.05). Rasmussen tibial plateau score in group A was slightly lower than that in group B (P > .05). The excellent rate of knee joint function in group A was 80% and 84.21% in group B (P > .05). External fixation combined with delayed open reduction and internal fixation is a safer and more efficacious therapy of tibial plateau fracture complicated with dislocation compared with early calcaneus traction and open reduction and internal fixation. PMID:29019890

  6. [effectiveness of open reduction and internal fixation without opening joint capsule on tibial plateau fracture].

    PubMed

    Chen, Qi; Xu, Xiaofeng; Huang, Yonghui; Cao, Xingbing; Meng, Chen; Cao, Xueshu; Wei, Changbao

    2014-12-01

    To introduce the surgery method to reset and fix tibial plateau fracture without opening joint capsule, and evaluate the safety and effectiveness of this method. Between July 2011 and July 2013, 51 patients with tibial plateau fracture accorded with the inclusion criteria were included. All of 51 patients, 17 cases underwent open reduction and internal fixation without opening joint capsule in trial group, and 34 cases underwent traditional surgery method in control group. There was no significant difference in gender, age, cause of injury, time from injury to admission, side of injury, and types of fracture between 2 groups (P > 0.05). The operation time, intraoperative blood loss, incision length, incision healing, and fracture healing were compared between 2 groups. The tibial-femoral angle and collapse of joint surface were measured on X-ray film. At last follow-up, joint function was evaluated with Hospital for Special Surgery (HSS) knee function scale. The intraoperative blood loss in trial group was significantly less than that in control group (P < 0.05). The incision length in trial group was significantly shorter than that in control group (P < 0.05). Difference was not significant in operation time and the rate of incision healing between 2 groups (P > 0.05). The patients were followed up 12-30 months (mean, 20.4 months) in trial group and 12-31 months (mean, 18.2 months) in control group. X-ray films indicated that all cases in 2 groups obtained fracture healing; there was no significant difference in the fracture healing time between 2 groups (t=1.382, P=0.173). On X-ray films, difference was not significant in tibial-femoral angle and collapse of joint surface between 2 groups (P > 0.05). HSS score of the knee in trial group was significantly higher than that of control group (t=3.161, P=0.003). It can reduce the intraoperative blood loss and shorten the incision length to use open reduction and internal fixation without opening joint capsule for

  7. Atrophic, aseptic, tibial nonunion: how effective is modified Judet's osteoperiosteal decortication technique and buttress plating?

    PubMed

    Binod, Bijukachhe; Nagmani, Singh; Bigyan, Bhandari; Rakesh, John; Prashant, Adhikari

    2016-08-01

    Tibial nonunion is the most common nonunion encountered by the orthopedic surgeon. Repeated surgeries, cost, increased duration of hospital stay, disability, pain all contribute to the increased morbidity. Many methods have been used to treat nonunion of tibia with variable results and none of them are 100 % successful. Our objective was to determine the effectiveness of modification of Judet's decortication technique and buttress plating, without bone graft, in the treatment of aseptic, atrophic tibial nonunion. Also, to find the correlation between time of achieving union and time since injury to decortication. Ours is a retrospective study conducted at a Level I trauma center. A total of 35 cases of atrophic tibial nonunion, irrespective of the cause, was treated by modifying Judet's osteoperiosteal decortication and plating during the time period January 2006 to July 2013. Demographic data, range of motion, time of achieving union and clinico-radiological evaluation for union of fracture were included as main outcome measurements. Union was achieved in all cases with a mean duration of 8.34 months. Pain and stiffness of joints were not reported in any case on long-term follow-up and the patients had satisfactory range of motion. Implant removal was done in three cases after fracture union. Treatment of atrophic tibial nonunion is challenging and management of each nonunion has to be customized based on the biological and mechanical characteristics of the nonunion. Plating with osteoperiosteal decortication is an effective and simple technique, which in our hands has shown to result in 100 % union rates without the need of additional bone healing augmentation procedures like bone grafting. Level II.

  8. Intermittent Parathyroid Hormone Enhances Cancellous Osseointegration of a Novel Murine Tibial Implant

    PubMed Central

    Yang, Xu; Ricciardi, Benjamin F.; Dvorzhinskiy, Aleksey; Brial, Caroline; Lane, Zachary; Bhimani, Samrath; Burket, Jayme C.; Hu, Bin; Sarkisian, Alexander M.; Ross, F. Patrick; van der Meulen, Marjolein C.H.; Bostrom, Mathias P.G.

    2015-01-01

    Background: Long-term fixation of uncemented joint implants requires early mechanical stability and implant osseointegration. To date, osseointegration has been unreliable and remains a major challenge in cementless total knee arthroplasty. We developed a murine model in which an intra-articular proximal tibial titanium implant with a roughened stem can be loaded through the knee joint. Using this model, we tested the hypothesis that intermittent injection of parathyroid hormone (iPTH) would increase proximal tibial cancellous osseointegration. Methods: Ten-week-old female C57BL/6 mice received a subcutaneous injection of PTH (40 μg/kg/day) or a vehicle (n = 45 per treatment group) five days per week for six weeks, at which time the baseline group was killed (n = 6 per treatment group) and an implant was inserted into the proximal part of the tibiae of the remaining mice. Injections were continued until the animals were killed at one week (n = 7 per treatment group), two weeks (n = 14 per treatment group), or four weeks (n = 17 per treatment group) after implantation. Outcomes included peri-implant bone morphology as analyzed with micro-computed tomography (microCT), osseointegration percentage and bone area fraction as shown with backscattered electron microscopy, cellular composition as demonstrated by immunohistochemical analysis, and pullout strength as measured with mechanical testing. Results: Preimplantation iPTH increased the epiphyseal bone volume fraction by 31.6%. When the data at post-implantation weeks 1, 2, and 4 were averaged for the iPTH-treated mice, the bone volume fraction was 74.5% higher in the peri-implant region and 168% higher distal to the implant compared with the bone volume fractions in the same regions in the vehicle-treated mice. Additionally, the trabecular number was 84.8% greater in the peri-implant region and 74.3% greater distal to the implant. Metaphyseal osseointegration and bone area fraction were 28.1% and 70.1% higher

  9. Intermittent Parathyroid Hormone Enhances Cancellous Osseointegration of a Novel Murine Tibial Implant.

    PubMed

    Yang, Xu; Ricciardi, Benjamin F; Dvorzhinskiy, Aleksey; Brial, Caroline; Lane, Zachary; Bhimani, Samrath; Burket, Jayme C; Hu, Bin; Sarkisian, Alexander M; Ross, F Patrick; van der Meulen, Marjolein C H; Bostrom, Mathias P G

    2015-07-01

    Long-term fixation of uncemented joint implants requires early mechanical stability and implant osseointegration. To date, osseointegration has been unreliable and remains a major challenge in cementless total knee arthroplasty. We developed a murine model in which an intra-articular proximal tibial titanium implant with a roughened stem can be loaded through the knee joint. Using this model, we tested the hypothesis that intermittent injection of parathyroid hormone (iPTH) would increase proximal tibial cancellous osseointegration. Ten-week-old female C57BL/6 mice received a subcutaneous injection of PTH (40 μg/kg/day) or a vehicle (n = 45 per treatment group) five days per week for six weeks, at which time the baseline group was killed (n = 6 per treatment group) and an implant was inserted into the proximal part of the tibiae of the remaining mice. Injections were continued until the animals were killed at one week (n = 7 per treatment group), two weeks (n = 14 per treatment group), or four weeks (n = 17 per treatment group) after implantation. Outcomes included peri-implant bone morphology as analyzed with micro-computed tomography (microCT), osseointegration percentage and bone area fraction as shown with backscattered electron microscopy, cellular composition as demonstrated by immunohistochemical analysis, and pullout strength as measured with mechanical testing. Preimplantation iPTH increased the epiphyseal bone volume fraction by 31.6%. When the data at post-implantation weeks 1, 2, and 4 were averaged for the iPTH-treated mice, the bone volume fraction was 74.5% higher in the peri-implant region and 168% higher distal to the implant compared with the bone volume fractions in the same regions in the vehicle-treated mice. Additionally, the trabecular number was 84.8% greater in the peri-implant region and 74.3% greater distal to the implant. Metaphyseal osseointegration and bone area fraction were 28.1% and 70.1% higher, respectively, in the i

  10. Hybrid external fixation in the treatment of tibial pilon fractures: A retrospective analysis of 162 fractures.

    PubMed

    Galante, Vito N; Vicenti, Giovanni; Corina, Gianfranco; Mori, Claudio; Abate, Antonella; Picca, Girolamo; Conserva, Vito; Speciale, Domenico; Scialpi, Lorenzo; Tartaglia, Nicola; Caiaffa, Vincenzo; Moretti, Biagio

    2016-10-01

    To determine the efficacy of hybrid external fixation in the treatment of tibial pilon fractures. Retrospective, multicentre study. Adult patients with tibial pilon fractures treated with hybrid external fixation. Fracture reduction with ligamentotaxis and fixation with XCaliber hybrid external fixator. Fracture union, complications, functional outcome (Mazur Ankle Score). Union was obtained in 159 fractures at an average of 125days; there were three delayed unions and three non-unions. The most frequent complication was superficial pin-track infections (48), all of which responded to local wound care and antibiotics. There were no deep infections and no DVT. Only one fracture had loss of reduction that required frame revision. The overall functional scores were 91 (excellent) for AO/OTA type A fractures, 89 (good) for type B fractures, and 75 (satisfactory) for type C fractures. Hybrid external fixation is an effective method of stabilising tibial pilon fractures, particularly those with marked comminution. The minimally-invasive technique and stable fixation enable early mobilisation, with good functional results and minimal complications. Level IV Case series. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Correlation between hindfoot joint three-dimensional kinematics and the changes of the medial arch angle in stage II posterior tibial tendon dysfunction flatfoot.

    PubMed

    Zhang, Yi-Jun; Xu, Jian; Wang, Yue; Lin, Xiang-Jin; Ma, Xin

    2015-02-01

    The aim of this study was to explore the correlation between the kinematics of the hindfoot joint and the medial arch angle change in stage II posterior tibial tendon dysfunction flatfoot three-dimensionally under loading. Computed tomography (CT) scans of 12 healthy feet and 12 feet with stage II posterior tibial tendon dysfunction flatfoot were taken both in non- and full-body-weight-bearing condition. The CT images of the hindfoot bones were reconstructed into three-dimensional models with Mimics and Geomagic reverse engineering software. The three-dimensional changes of the hindfoot joint were calculated to determine their correlation to the medial longitudinal arch angle. The medial arch angle change was larger in stage II posterior tibial tendon dysfunction flatfoot compared to that in healthy foot under loading. The rotation and translation of the talocalcaneal joint, the talonavicular joint and the calcanocuboid joint had little influence on the change of the medial arch angle in healthy foot. However, the eversion of the talocalcaneal joint, the proximal translation of the calcaneus relative to the talus and the dorsiflexion of talonavicular joint could increase the medial arch angle in stage II posterior tibial tendon dysfunction flatfoot under loading. Joint instability occurred in patients with stage II posterior tibial tendon dysfunction flatfoot under loading. Limitation of over movement of the talocalcaneal joint and the talonavicular joint may help correct the medial longitudinal arch in stage II posterior tibial tendon dysfunction flatfoot. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Insertion device and method for accurate and repeatable target insertion

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gubeli, III, Joseph F.; Shinn, Michelle D.; Bevins, Michael E.

    The present invention discloses a device and a method for inserting and positioning a target within a free electron laser, particle accelerator, or other such device that generates or utilizes a beam of energy or particles. The system includes a three-point registration mechanism that insures angular and translational accuracy and repeatability of positioning upon multiple insertions within the same structure.

  13. A high rate of tibial plateau fractures after early experience with patient-specific instrumentation for unicompartmental knee arthroplasties.

    PubMed

    Leenders, A M; Schotanus, M G M; Wind, R J P; Borghans, R A P; Kort, N P

    2018-04-30

    Patient-specific instrumentation (PSI) for unicompartmental knee arthroplasty (UKA) has been available for a few years. However, limited literature is available on this subject. Hence, the aim of this cohort study is to evaluate the 2 years' results of our first experiences with the use of PSI in UKA. It is hypothesised that there is no advantage in rate of adverse events and in radiological and functional outcomes in comparison to literature on the conventional method. This cohort included 129 knees of 122 patients, operated by one surgeon. Outcome measures were the rate of adverse events (AEs); implant position as determined on radiographs; the accuracy of the default and approved planning of the implant sizes and the patient-reported outcome measures (PROMs) preoperatively, and at 3, 12 and 24 months, postoperatively. A total of 6 (4.9%) AEs were observed in this study, with 4 (3.3%) tibial fractures being the main complication. The mean postoperative biomechanical axis was 176.4° and in the majority of cases, the radiographic criteria, as determined by the manufacturer, were met. The tibial component showed 20 (16.4%) outliers in the sagittal and 3 (2.5%) outliers in the frontal plane. There were no outliers of the femoral component. For the femoral and tibial components, respectively, in 125 (96.9%) and 79 (61.7%) cases, there was an agreement between approved planning and implanted component size. All PROMs improved significantly after surgery. Tibial fracture was the most common AE, probably related to the transition from cemented to uncemented UKA. Perioperative modifications to the surgical technique were made in order to prevent this AE. Improvements should be made to the operation technique of the uncemented tibial plateau to obtain an adequate placement and at the same time reduce the risk for tibial fracture. The PSI technique was a reliable tool for the placement of the femoral component. Functional outcome was in line with literature on the

  14. Patient reported health related quality of life early outcomes at 12 months after surgically managed tibial plafond fracture.

    PubMed

    Bonato, Luke J; Edwards, Elton R; Gosling, Cameron McR; Hau, Raphael; Hofstee, Dirk Jan; Shuen, Alex; Gabbe, Belinda J

    2017-04-01

    Tibial plafond fractures represent a small but complex subset of fractures of the lower limb. The aim of this study was to describe the health related quality of life, pain and return to work outcomes 12 months following surgically managed tibial plafond fracture. The Victorian Orthopaedic Trauma Outcomes Registry (VOTOR) database was used to identify patients with tibial plafond fractures. All patients captured by VOTOR with a tibial plafond fracture between September 2003 and July 2009, were identified consecutively and comprised the initial cohort. The radiographs of all identified patients were classified using the AO/OTA fracture classification. A review of the included patient's medical records was performed. Data were collected on the injury event, management and complications. Outcomes at 12 months were prospectively collected by telephone interview and included return to work, a numerical rating scale for assessment of pain and the Short Form 12 (SF-12). There were 98 unilateral tibial plafond fractures; 91 fractures were managed operatively, 4 non-operatively and 3 underwent amputation. The 91 operatively managed patients were the focus of this study. A two-stage management approach, involving temporary external fixation, followed by definitive open reduction and internal fixation, was the most common operative treatment. The follow-up rate at 12 months was 70%. 57% had returned to work by 12 months post-injury, the median (IQR) pain score was 2 (0-5) and 27% reported moderate to severe persistent pain. Mean PCS-12 scores were significantly lower than Australian norms (p=0.99), 38.2 for males and 37.5 for females. The presence of persistent pain, loss of physical health and a low return to work rate highlights the profound impact of tibial plafond fractures on patients' lives. Although this study looked at the early 12 month results, it is expected these outcomes will continue to improve over time. Further studies, with larger patient numbers, must focus

  15. Effect of open wedge high tibial osteotomy on the lateral tibiofemoral compartment in sheep. Part II: standard and overcorrection do not cause articular cartilage degeneration.

    PubMed

    Ziegler, Raphaela; Goebel, Lars; Cucchiarini, Magali; Pape, Dietrich; Madry, Henning

    2014-07-01

    To evaluate whether medial open wedge high tibial osteotomy (HTO) results in structural changes in the articular cartilage in the lateral tibiofemoral compartment of adult sheep. Three experimental groups received biplanar osteotomies of the right proximal tibiae: (a) closing wedge HTO (4.5° of tibial varus), (b) opening wedge HTO (4.5° tibial valgus; standard correction), and (c) opening wedge HTO (9.5° of valgus; overcorrection), each of which was compared to the contralateral knees that only received an arthrotomy. After 6 months, the macroscopic and microscopic characteristics of the articular cartilage of the lateral tibiofemoral compartment were assessed. The articular cartilage in the central region of the lateral tibial plateau in sheep had a higher safranin O staining intensity and was 4.6-fold thicker than in the periphery (covered by the lateral meniscus). No topographical variation in the type-II collagen immunoreactivity was seen. All lateral tibial plateaus showed osteoarthritic changes in regions not covered by the lateral meniscus. No osteoarthritis was seen in the peripheral submeniscal regions of the lateral tibial plateau and the lateral femoral condyle. Opening wedge HTO resulting in both standard and overcorrection was not associated with significant macroscopic and microscopic structural changes between groups in the articular cartilage of the lateral tibial plateau and femoral condyle after 6 months in vivo. Opening wedge HTO resulting in both standard and overcorrection is a safe procedure for the articular cartilage in an intact lateral tibiofemoral compartment of adult sheep at 6 months postoperatively.

  16. Anatomical dissection and CT imaging of the posterior cruciate and lateral collateral ligaments in skeletally immature cadaver knees.

    PubMed

    Shea, Kevin G; Polousky, John D; Jacobs, John C; Ganley, Theodore J

    2014-05-07

    Understanding the relationship of the posterior cruciate ligament (PCL) and the lateral collateral ligament (LCL) to the femoral and tibial physes is important to reducing the risk of physeal injury during surgical reconstruction. The purpose of this study was to identify the location of the attachments of the PCL and LCL in skeletally immature cadaveric knee specimens and to determine their position relative to the physes. Seven skeletally immature cadaveric knee specimens were examined through gross dissection. These specimens were divided into two groups: infants (an age at death of one month for one specimen and eleven months for two specimens) and children (an age at death of eight years for one specimen, ten years for one specimen, and eleven years for two specimens). Metallic markers were placed at the femoral origins of the PCL and LCL and at the tibial insertion of the PCL. Computed tomography (CT) scans were made for each specimen and analyzed with the use of OsiriX imaging software. The width of the PCL tibial insertion footprint and the height of the PCL femoral origin footprint, the distance from the midpoints of the PCL and LCL femoral origin to the distal femoral physis, and the distance from the PCL insertion footprint midpoint to the proximal tibial physis were measured. The mean distance from the midpoint of the femoral origin footprint of the PCL to the femoral physis was 11.1 mm (range, 10.6 to 11.7 mm) and 18.8 mm (range, 18.2 to 19.2 mm) distal to the physis for infants and children, respectively. The mean distance from the midpoint of the tibial insertion footprint of the PCL to the tibial physis was 3.1 mm (range, 0.0 to 5.7 mm) and 5.8 mm (range, 2.5 to 8.9 mm) proximal to the physis for infants and children, respectively. The mean width of the tibial insertion of the PCL was 5.5 mm (range, 1.1 to 8.3 mm) for infants and 10.2 mm (range, 8.4 to 11.9 mm) for children. The mean distance from the midpoint of the femoral origin of the LCL to the

  17. Bracing can partially limit tibial rotation during stressful activities after anterior crucial ligament reconstruction with a hamstring graft.

    PubMed

    Giotis, D; Paschos, N K; Zampeli, F; Pappas, E; Mitsionis, G; Georgoulis, A D

    2016-09-01

    Hamstring graft has substantial differences with BPTB graft regarding initial mechanical strength, healing sequence, and vascularization, which may imply that a different approach during rehabilitation period is required. The purpose of this study was to investigate the influence of knee bracing on tibial rotation in ACL-reconstructed patients with a hamstring autograft during high loading activities. The hypothesis was that there would be a decrease in tibial rotation in the ACL-reconstructed braced knee as compared to the unbraced knee. Twenty male patients having undergone unilateral ACL reconstruction with a semitendinosus/gracilis autograft were assessed. Kinematic data were collected with an eight-camera optoelectronic system during two stressful tasks: (1) descending from a stair and subsequent pivoting; and (2) landing from a platform and subsequent pivoting. In each patient, three different experimental conditions were evaluated: (A) wearing a prophylactic brace (braced condition); (B) wearing a patellofemoral brace (sleeved condition); (C) without brace (unbraced condition). The intact knee without brace served as a control. Tibial rotation was significantly lower in the intact knee compared to all three conditions of the ACL-reconstructed knee (P≤0.01 for both tasks). Presence of a brace or sleeve resulted in lower tibial rotation than in the unbraced condition (p=0.003 for descending/pivot and P=0.0004 for landing/pivot). The braced condition resulted in lower rotation than the sleeved condition for descending/pivoting (P=0.031) while no differences were found for landing/pivoting (P=0.230). Knee bracing limited the excessive tibial rotation during pivoting under high loading activities in ACL-reconstructed knees with a hamstring graft. This partial restoration of normal kinematics may have a potential beneficial effect in patients recovering from ACL reconstruction with a hamstring autograft. Level III, case-control therapeutic study. Copyright

  18. Highly Crosslinked-remelted versus Less-crosslinked Polyethylene in Posterior Cruciate-retaining TKAs in the Same Patients.

    PubMed

    Kim, Young-Hoo; Park, Jang-Won; Kim, Jun-Shik; Lee, June-Hyung

    2015-11-01

    Concern regarding osteolysis attributable to polyethylene wear after TKA, particularly in younger patients, has prompted the introduction of highly crosslinked-remelted polyethylene (HXLPE) for TKAs. However, few in vivo comparative results of TKAs using HXLPE and less-crosslinked polyethylene inserts in the same patients are available, regarding fracture or failure of the locking mechanism of tibial polyethylene inserts or of osteolysis in patients younger than 60 years. We wanted to determine whether (1) survivorship free from aseptic loosening in knees with HXLPE inserts was different from survivorship in knees with less-crosslinked polyethylene inserts, (2) the prevalence of fracture or failure of the locking mechanism of the tibial polyethylene insert was greater in knees with HXLPE than in those with less-crosslinked polyethylene, and (3) the proportion of patients who had osteolysis develop was greater with HXLPE than with less-crosslinked polyethylene inserts. One hundred seventy-one patients with a mean age of 58 ± 8 years (range, 35-59 years) received posterior cruciate-retaining prostheses with a less-crosslinked polyethylene tibial insert in one knee and a HXLPE tibial insert in the contralateral knee. From January 2007 to January 2010, we performed 366 same-day bilateral simultaneous sequential posterior cruciate-retaining TKAs in 183 patients, of whom 171 (93%) participated in this study. All patients during this study period underwent posterior cruciate-retaining TKAs regardless of deformity of the knees and we did not perform posterior-stabilized TKAs during the same period. Patients who had bilateral end-stage osteoarthritis and were younger than 60 years were selected for inclusion. Six patients (4%) were lost to followup before 5 years. Twenty-six patients were males and 145 were females. The mean duration of followup was 6 years (range, 5-8 years). At each followup, patients were assessed for loosening of the components, fracture or failure of

  19. Multiple Osteochondral Allograft Transplantation with Concomitant Tibial Tubercle Osteotomy for Multifocal Chondral Disease of the Knee.

    PubMed

    Cotter, Eric J; Waterman, Brian R; Kelly, Mick P; Wang, Kevin C; Frank, Rachel M; Cole, Brian J

    2017-08-01

    Symptomatic patellofemoral chondral lesions are a challenging clinical entity, as these defects may result from persistent lateral patellar maltracking or repetitive microtrauma. Anteromedializing tibial tubercle osteotomy has been shown to be an effective strategy for primary and adjunctive treatment of focal or diffuse patellofemoral disease to improve the biomechanical loading environment. Similarly, osteochondral allograft transplantation has proven efficacy in physiologically young, high-demand patients with condylar or patellofemoral lesions, particularly without early arthritic progression. The authors present the surgical management of a young athlete with symptomatic tricompartmental focal chondral defects with fresh osteochondral allograft transplantation and anteromedializing tibial tubercle osteotomy.

  20. Impingement of the Mobile Bearing on the Lateral Wall of the Tibial Tray in Unicompartmental Knee Arthroplasty.

    PubMed

    Inui, Hiroshi; Taketomi, Shuji; Yamagami, Ryota; Sanada, Takaki; Shirakawa, Nobuyuki; Tanaka, Sakae

    2016-07-01

    Tilting of the mobile bearing relative to the tibial tray in the flexion position may result from the implantation of femoral components more laterally relative to tibial components during unicompartmental knee arthroplasty (UKA) using the Oxford Knee. The purpose of the present study was to compare femoral component positions after UKA using the phase 3 device and a novel device. We further evaluated the placement of the femoral components with the new device in the flexion position to determine the association with short-term prognosis. The location of femoral and tibial components in the flexion position of 38 knees implanted using the phase 3 device and 49 knees using a novel device was assessed at 1 year postoperatively using radiography of the proximal tibia and distal femur in the flexion position. The femoral component was implanted more laterally using the new device than using the phase 3 device in the flexion position (P = .012), which caused the impingement of the mobile bearing against the lateral wall of the tibial tray. After UKA using the new device, 10% of patients exhibited the tilting phenomenon of the mobile bearing because of the lateral implantation of the femoral implant. To prevent implantation of the femoral component too laterally using the new device during UKA, knee surgeons should set the drill guide more medially such that the center of the drill is aligned with the middle of the medial femoral condyle. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. CR TKA UHMWPE wear tested after artificial aging of the vitamin E treated gliding component by simulating daily patient activities.

    PubMed

    Schwiesau, Jens; Fritz, Bernhard; Kutzner, Ines; Bergmann, Georg; Grupp, Thomas M

    2014-01-01

    The wear behaviour of total knee arthroplasty (TKA) is dominated by two wear mechanisms: the abrasive wear and the delamination of the gliding components, where the second is strongly linked to aging processes and stress concentration in the material. The addition of vitamin E to the bulk material is a potential way to reduce the aging processes. This study evaluates the wear behaviour and delamination susceptibility of the gliding components of a vitamin E blended, ultra-high molecular weight polyethylene (UHMWPE) cruciate retaining (CR) total knee arthroplasty. Daily activities such as level walking, ascending and descending stairs, bending of the knee, and sitting and rising from a chair were simulated with a data set received from an instrumented knee prosthesis. After 5 million test cycles no structural failure of the gliding components was observed. The wear rate was with 5.62 ± 0.53 mg/million cycles falling within the limit of previous reports for established wear test methods.

  2. CR TKA UHMWPE Wear Tested after Artificial Aging of the Vitamin E Treated Gliding Component by Simulating Daily Patient Activities

    PubMed Central

    Schwiesau, Jens; Fritz, Bernhard; Kutzner, Ines; Bergmann, Georg; Grupp, Thomas M.

    2014-01-01

    The wear behaviour of total knee arthroplasty (TKA) is dominated by two wear mechanisms: the abrasive wear and the delamination of the gliding components, where the second is strongly linked to aging processes and stress concentration in the material. The addition of vitamin E to the bulk material is a potential way to reduce the aging processes. This study evaluates the wear behaviour and delamination susceptibility of the gliding components of a vitamin E blended, ultra-high molecular weight polyethylene (UHMWPE) cruciate retaining (CR) total knee arthroplasty. Daily activities such as level walking, ascending and descending stairs, bending of the knee, and sitting and rising from a chair were simulated with a data set received from an instrumented knee prosthesis. After 5 million test cycles no structural failure of the gliding components was observed. The wear rate was with 5.62 ± 0.53 mg/million cycles falling within the limit of previous reports for established wear test methods. PMID:25506594

  3. Software-implemented fault insertion: An FTMP example

    NASA Technical Reports Server (NTRS)

    Czeck, Edward W.; Siewiorek, Daniel P.; Segall, Zary Z.

    1987-01-01

    This report presents a model for fault insertion through software; describes its implementation on a fault-tolerant computer, FTMP; presents a summary of fault detection, identification, and reconfiguration data collected with software-implemented fault insertion; and compares the results to hardware fault insertion data. Experimental results show detection time to be a function of time of insertion and system workload. For the fault detection time, there is no correlation between software-inserted faults and hardware-inserted faults; this is because hardware-inserted faults must manifest as errors before detection, whereas software-inserted faults immediately exercise the error detection mechanisms. In summary, the software-implemented fault insertion is able to be used as an evaluation technique for the fault-handling capabilities of a system in fault detection, identification and recovery. Although the software-inserted faults do not map directly to hardware-inserted faults, experiments show software-implemented fault insertion is capable of emulating hardware fault insertion, with greater ease and automation.

  4. Quantification of the Effect of Cross-shear on the Wear of Conventional and Highly Cross-linked UHMWPE

    PubMed Central

    Kang, Lu; Galvin, Alison L.; Brown, Thomas D.; Jin, Zhongmin; Fisher, John

    2008-01-01

    A computational model has been developed to quantify the degree of cross-shear of a polyethylene pin articulating against a metallic plate, based on the direct simulation of a multidirectional pin-on-plate wear machine. The principal molecular orientation (PMO) was determined for each polymer site. The frictional work in the direction perpendicular to the PMO was assumed to produce the greatest orientation softening (Wang et al., 1997). The cross-shear ratio (CS) was defined as the frictional work perpendicular to the PMO direction, divided by the total frictional work. Cross-shear on the pin contact surface was location-specific, and of continuously changing magnitude because the direction of frictional force continuously changed due to pin rotation. The polymer pin motion was varied from a purely linear track (CS=0) up to a maximum rotation of ±55° (CS=0.254). The relationship between wear factors (K) measured experimentally and theoretically predicted CS was defined using logarithmic functions for both conventional and highly cross-linked UHMWPE. Cross-shear increased the apparent wear factor for both polyethylenes by more than 5-fold compared to unidirectional wear. PMID:17936763

  5. Anatomy and classification of the posterior tibial fragment in ankle fractures.

    PubMed

    Bartoníček, Jan; Rammelt, Stefan; Kostlivý, Karel; Vaněček, Václav; Klika, Daniel; Trešl, Ivo

    2015-04-01

    The aim of this study was to analyze the pathoanatomy of the posterior fragment on the basis of a comprehensive CT examination, including 3D reconstructions, in a large patient cohort. One hundred and forty one consecutive individuals with an ankle fracture or fracture-dislocation of types Weber B or Weber C and evidence of a posterior tibial fragment in standard radiographs were included in the study. The mean patient age was 49 years (range 19-83 years). The exclusion criteria were patients below 18 years of age, inability to provide written consent, fractures of the tibial pilon, posttraumatic arthritis and pre-existing deformities. In all patients, post-injury radiographs were obtained in anteroposterior, mortise and lateral views. All patients underwent CT scanning in transverse, sagittal and frontal planes. 3D CT reconstruction was performed in 91 patients. We were able to classify 137 cases into one of the following four types with constant pathoanatomic features: type 1: extraincisural fragment with an intact fibular notch, type 2: posterolateral fragment extending into the fibular notch, type 3: posteromedial two-part fragment involving the medial malleolus, type 4: large posterolateral triangular fragment. In the 4 cases it was not possible to classify the type of the posterior tibial fragment. These were collectively termed type 5 (irregular, osteoporotic fragments). It is impossible to assess the shape and size of the posterior malleolar fragment, involvement of the fibular notch, or the medial malleolus, on the basis of plain radiographs. The system that we propose for classification of fractures of the posterior malleolus is based on CT examination and takes into account the size, shape and location of the fragment, stability of the tibio-talar joint and the integrity of the fibular notch. It may be a useful indication for surgery and defining the most useful approach to these injuries.

  6. External fixation using locking plate in distal tibial fracture: a finite element analysis.

    PubMed

    Zhang, Jingwei; Ebraheim, Nabil; Li, Ming; He, Xianfeng; Schwind, Joshua; Liu, Jiayong; Zhu, Limei

    2015-08-01

    External fixation of tibial fractures using a locking plate has been reported with favorable results in some selected patients. However, the stability of external plate fixation in this fracture pattern has not been previously demonstrated. We investigated the stability of external plate fixation with different plate-bone distances. In this study, the computational processing model of external fixation of a distal tibial metaphyseal fracture utilizing the contralateral femoral less invasive stabilization system plate was analyzed. The plate was placed on the anteromedial aspect of tibia with different plate-bone distances: 1, 10, 20, and 30 mm. Under axial load, the stiffness of construct in all groups was higher than intact tibia. Under axial load with an internal rotational force, the stiffness of construct with 1 and 10 mm plate-bone distances was similar to that of an intact tibia and the stiffness of the construct with 20 and 30 mm distances was lower than that of an intact tibia. Under axial load with an external rotational force, the stiffness of the construct in all groups was lower than that of an intact tibia. The maximum plate stresses were concentrated at the two most distal screws and were highest in the construct with the 10 mm plate-bone distance, and least in the construct with a 1 mm plate-bone distance. To guarantee a stable external plate fixation in distal tibial fracture, the plate-bone distance should be less than 30 mm.

  7. Total knee replacement with tibial tubercle osteotomy in rheumatoid patients with stiff knee.

    PubMed

    Eid, Ahmed Salem; Nassar, Wael Ahmed Mohamed; Fayyad, Tamer Abdelmeguid Mohamed

    2016-11-01

    Total knee arthroplasty (TKA) is a well-proven modality that can provide pain relief and restore mobility for rheumatoid arthritis (RA) patients with advanced joint destruction. Patellar ligament avulsion, especially in presence of poor bone quality and knee stiffness, is one of the special considerations that must be addressed in this unique population of patients. This study aimed to determine the functional results in a series of rheumatoid patients with stiff knee and end-stage joint destruction who underwent tibial tubercle osteotomy during TKA. Twenty-three knees in 20 patients (16 women; four men) at a mean age of 54 years with end-stage arthritis and knee stiffness due to RA were operated upon for TKA using tibial tubercle osteotomy as a step during the operation. Patients were reviewed clinically and radiographically with a minimum follow-up of two years. Complications were noted. Hospital for Special Surgery (HSS) score was recorded pre-operatively and at six and 12 months postoperatively. Union occurred at the osteotomy site in 21 of 23 cases. One case had deep venous thrombosis (DVT). There was no infection or periprosthetic fracture, and at last follow-up, no patient required revision. HSS score improved from 46 (15-60) pre-operatively to 85 (71-96) post-operatively. Tibial tubercle osteotomy during TKA in patients with RA and stiff knee is technically demanding yet proved to be effective in improving post-operative range of movement and minimising the complication of patellar ligament avulsion.

  8. Low-energy fracture of posterolateral tibial plateau: treatment by a posterolateral prone approach.

    PubMed

    Yu, Guang-Rong; Xia, Jiang; Zhou, Jia-Qian; Yang, Yun-Feng

    2012-05-01

    Most of the posterolateral tibial plateau fractures are caused by low-energy injury. The posterior fracture fragment could not be exposed and reduced well through traditional approaches. The aim of this study was to review the results of surgical treatment of this kind of fracture using posterolateral approach with patient in prone position. The low-energy posterolateral fracture is defined as the main part of articular depression or split fragment limited within the posterior half of the lateral column. Direct reduction and buttress plate fixation through the posterolateral prone approach was applied in all the patients. In our series, 15 of 132 (11.4%) patients with tibial plateau fractures were identified as low-energy posterolateral fractures. The clinical outcomes were available in 14 of the 15 patients through phone interviews and chart reviews. Mean follow-up was 35.1 months (range: 24-48 months). All the patients had anatomic or good reductions (≤ 2 mm step/gap). Average range of motion was 0.7 degrees to 123.2 degrees (5-110 degrees to 0-140 degrees). The complications were limited to one superficial wound infection, two slight flexion contractures, and five implants removal. The average modified hospital for special surgery knee score was 93.4 (range: 86-100). The posterolateral prone approach provides excellent visualization, which can facilitate the reduction and posterior buttress plate fixation for low-energy posterolateral tibial plateau fractures and shows encouraging results. V, therapeutic study.

  9. Surgical anatomy of medial open-wedge high tibial osteotomy: crucial steps and pitfalls.

    PubMed

    Madry, Henning; Goebel, Lars; Hoffmann, Alexander; Dück, Klaus; Gerich, Torsten; Seil, Romain; Tschernig, Thomas; Pape, Dietrich

    2017-12-01

    To give an overview of the basic knowledge of the functional surgical anatomy of the proximal lower leg and the popliteal region relevant to medial high tibial osteotomy (HTO) as key anatomical structures in spatial relation to the popliteal region and the proximal tibiofibular joint are usually not directly visible and thus escape a direct inspection. The surgical anatomy of the human proximal lower leg and its relevance for HTO are illustrated with a special emphasis on the individual steps of the operation involving creation of the osteotomy planes and plate fixation. The posteriorly located popliteal neurovascular bundle, but also lateral structures such as the peroneal nerve, the head of the fibula and the lateral collateral ligament must be protected from the instruments used for osteotomy. Neither positioning the knee joint in flexion, nor the posterior thin muscle layer of the popliteal muscle offers adequate protection of the popliteal neurovascular bundle when performing the osteotomy. Tactile feedback through a loss-of-resistance when the opposite cortex is perforated is only possible when sawing and drilling is performed in a pounding fashion. Kirschner wires with a proximal thread, therefore, always need to be introduced under fluoroscopic control. Due to anatomy of the tibial head, the tibial slope may increase inadvertently. Enhanced surgical knowledge of anatomical structures that are at a potential risk during the different steps of osteotomy or plate fixation will help to avoid possible injuries. Expert opinion, Level V.

  10. [Treatment of Schatzker IV tibial plateau fractures with arthroscopy combined with MIPPO technique].

    PubMed

    Li, Jian-Wen; Ye, Feng; Bi, Da-Wei; Zheng, Xiao-Dong; Chen, Jian-Liang

    2018-02-25

    To discusses the clinical effects of arthroscopy combined with minimally invasive percutaneous plate osteosynthesis(MIPPO) technology in treating Schatzker IV tibial plateau fractures. From January 2012 to January 2016, 19 patients with Schatzker type IV tibial plateau fractures were treated with arthroscopy combined with minimally invasive technique including 12 males and 7 females with an average age of 46.5 years old ranging from 19 to 78 years old. Patients were suffering knee pain, swelling, flexion and extension limited, and other symptoms preoperative. Patients were followed up and assessed by Rasmussen knee function score. No infection, traumatic arthritis, and knee joint valgus occurred after operation. Nineteen cases were followed up for 12 to 24 months with an average of 18.6 months. Fracture healing time was 3 to 5 months with an average of 3.8 months. The knee pain and limited mobility improved significantly. The range of autonomic movement of joints was from 90 to 136 degrees. According to Rasmussen functional score criteria, the total score was 27.00±2.49, the result was excellent in 16 cases, good in 2 cases, fair in 1 case. Arthroscopic treatment for Schatzker type IV tibial plateau fractures combined with MIPPO can simultaneously treat internal structural injuries such as meniscus and other knee joints, with less trauma, fewer complications, and faster joint function recovery, but we must strictly grasp surgical indications and avoid expanding injuries. Copyright© 2018 by the China Journal of Orthopaedics and Traumatology Press.

  11. Relationship between tibial spine size and the occurrence of osteochondritis dissecans: an argument in favour of the impingement theory.

    PubMed

    Cavaignac, Etienne; Perroncel, Geoffroy; Thépaut, Mathias; Vial, Julie; Accadbled, Franck; De Gauzy, Jérôme Sales

    2017-08-01

    Pathophysiology of osteochondritis dissecans (OCD) of the medial femoral condyle remains uncertain. Specifically, the relationship between the size of the anterior tibial spine (ATS) and the presence of OCD has not been explored. The purpose of this study was to evaluate the relationship between ATS size and the occurrence of OCD. Seventy-nine children between 8 and 17 years of age were included in two groups: OCD (n = 37) and control (n = 42). The groups were matched in terms of age, gender, BMI and weight. Two independent observers performed an MRI analysis of the size of the tibial spine and intercondylar notch relative to the size of the respective epiphyses. For this study, the "S ratio" was calculated by dividing the height of the tibial spine by the height of the tibial epiphysis. The "N ratio" was calculated by dividing the height of the notch by the height of the femoral epiphysis. These two ratios for both groups were compared using Student's t test. The mean value of the S ratio in the OCD group was 0.39 ± 0.06; the mean value of the S ratio in the control group was 0.32 ± 0.03 (P = 0.004). The mean value of the N ratio in the OCD group was 0.70 ± 0.08; the mean value of the N ratio in the control group was 0.70 ± 0.07 (n.s.). This study's findings confirm our hypothesis that patients with OCD have a more prominent tibial spine than in patients without OCD. IV.

  12. [Biphasic ceramic wedge and plate fixation with locked adjustable screws for open wedge tibial osteotomy].

    PubMed

    Lavallé, F; Pascal-Mousselard, H; Rouvillain, J L; Ribeyre, D; Delattre, O; Catonné, Y

    2004-10-01

    The aim of this radiological study was to evaluate the use of a biphasic ceramic wedge combined with plate fixation with locked adjustable screws for open wedge tibial osteotomy. Twenty-six consecutive patients (27 knees) underwent surgery between December 1999 and March 2002 to establish a normal lower-limb axis. The series included 6 women and 20 men, mean age 50 years (16 right knees and 11 left knees). Partial weight-bearing with crutches was allowed on day 1. A standard radiological assessment was performed on day 1, 90, and 360 (plain AP and lateral stance films of the knee). A pangonogram was performed before surgery and at day 360. Presence of a lateral metaphyseal space, development of peripheral cortical bridges, and osteointegration of the bone substitute-bone interface were evaluated used to assess bone healing. The medial tibial angle between the line tangent to the tibial plateau and the anatomic axis of the tibia (beta) was evaluated to assess preservation of postoperative correction. The HKA angle was determined. Three patients were lost to follow-up and 23 patients (24 knees) were retained for analysis. At last follow-up, presence of peripheral cortical bridges and complete filling of the lateral metaphyseal space demonstrated bone healing in all patients. Good quality osteointegration was achieved since 21 knees did not present an interface between the bone substitute and native bone (homogeneous transition zone). The beta angle was unchanged for 23 knees. A normal axis was observed in patients (16 knees) postoperatively. Use of a biphasic ceramic wedge in combination with plate fixation with locked adjustable screws is a reliable option for open wedge tibial osteotomy. The bone substitute fills the gap well. Tolerance and integration are optimal. Bone healing is achieved. Plate fixation with protected weight bearing appears to be a solid assembly, maintaining these corrections.

  13. Changes in patellofemoral alignment do not cause clinical impact after open-wedge high tibial osteotomy.

    PubMed

    Lee, Yong Seuk; Lee, Sang Bok; Oh, Won Seok; Kwon, Yong Eok; Lee, Beom Koo

    2016-01-01

    The objectives of this study were (1) to evaluate the clinical and radiologic outcomes of open-wedge high tibial osteotomy focusing on patellofemoral alignment and (2) to search for correlation between variables and patellofemoral malalignment. A total of 46 knees (46 patients) from 32 females and 14 males who underwent open-wedge high tibial osteotomy were included in this retrospective case series. Outcomes were evaluated using clinical scales and radiologic parameters at the last follow-up. Pre-operative and final follow-up values were compared for the outcome analysis. For the focused analysis of the patellofemoral joint, correlation analyses between patellofemoral variables and pre- and post-operative weight-bearing line (WBL), clinical score, posterior slope, Blackburn Peel ratio, lateral patellar tilt, lateral patellar shift, and congruence angle were performed. The minimum follow-up period was 2 years and median follow-up period was 44 months (range 24-88 months). The percentage of weight-bearing line was shifted from 17.2 ± 11.1 to 56.7 ± 12.7%, and it was statistically significant (p < 0.01). Regarding the clinical results, statistical significance was observed using all scores (p < 0.01). In the radiologic evaluation, patellar descent was observed with statistical significance (p < 0.01). Last follow-up lateral patellar tilt was decreased with statistical significance (p < 0.01). In correlation analysis between variables of patellofemoral malalignment, the pre-operative weight-bearing line showed an association with the change in lateral patellar tilt and lateral patellar shift (correlation coefficient: 0.3). After open-wedge high tibial osteotomy, clinical results showed improvement, compared to pre-operative values. The patellar tilt and lateral patellar shift were not changed; however, descent of the patella was observed. Therefore, mild patellofemoral problems should not be a contraindication of the open-wedge high tibial osteotomy. Case series

  14. Can tibial plateau fractures be reduced and stabilised through an angiosome-sparing antero-lateral approach?

    PubMed

    Solomon, Lucian B; Boopalan, P R J V C; Chakrabarty, Adhiraj; Callary, Stuart A

    2014-04-01

    Tibial plateau fractures (TPFs) are an independent, non-modifiable risk factor for surgical site infections (SSIs). Current antero-lateral approaches to the knee dissect through the anterior tibial angiosome (ATA), which may contribute to a higher rate of SSIs. The aim of this study was to develop an angiosome-sparing antero-lateral approach to allow reduction and fixation of lateral TPFs and to investigate its feasibility in a consecutive cohort. Twenty cadaveric knees were dissected to define the position of the vessels supplying the ATA from the lateral tibial condyle to the skin perforators. Based on these results, an angiosome-sparing surgical approach to treat lateral TPFs was developed. Fifteen consecutive patients were subsequently treated through this approach. Clinical outcomes included assessment of SSI and Lysholm score. Fracture healing and stability were assessed using the Rasmussen score and radiostereometric analysis (RSA). At the latest follow-up between 1 and 4 years, there was no report of SSI. Nine patients (60%) had good or excellent Lysholm scores. The mean Rasmussen score at final follow-up was 17 (median 18, range 14-18) with 10 patients (66%) graded as excellent. Fracture fragment migration measured using RSA was below 2mm in all cases. This study has demonstrated that an angiosome-sparing antero-lateral approach to the lateral tibial plateau is feasible. Adequate stability of these fracture types was achieved by positioning a buttress plate away from the bone and superficial to the regional fascial layer as an 'internal-external fixator'. The angiosome-sparing approach developed was able to be used in a prospective cohort and the clinical results to date are encouraging. Future clinical studies need to investigate the potential benefits of this surgical approach when compared with the previously described antero-lateral approaches. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  15. Rap system of stress stimulation can promote bone union after lower tibial bone fracture: a clinical research.

    PubMed

    Yao, Jian-fei; Shen, Jia-zuo; Li, Da-kun; Lin, Da-sheng; Li, Lin; Li, Qiang; Qi, Peng; Lian, Ke-jian; Ding, Zhen-qi

    2012-01-01

    Lower tibial bone fracture may easily cause bone delayed union or nonunion because of lacking of dynamic mechanical load. Research Group would design a new instrument as Rap System of Stress Stimulation (RSSS) to provide dynamic mechanical load which would promote lower tibial bone union postoperatively. This clinical research was conducted from January 2008 to December 2010, 92 patients(male 61/female 31, age 16-70 years, mean 36.3 years) who suffered lower tibial bone closed fracture were given intramedullary nail fixation and randomly averagely separated into experimental group and control group(according to the successively order when patients went for the admission procedure). Then researchers analysed the clinical healing time, full weight bearing time, VAS (Visual Analogue Scales) score and callus growth score of Lane-Sandhu in 3,6,12 months postoperatively. The delayed union and nonunion rates were compared at 6 and 12 months separately. All the 92 patients had been followed up (mean 14 months). Clinical bone healing time in experimental group was 88.78±8.80 days but control group was 107.91±9.03 days. Full weight bearing time in experimental group was 94.07±9.81 days but control group was 113.24±13.37 days respectively (P<0.05). The delayed union rate in 6 months was 4.3% in experimental group but 10.9% in control group(P<0.05). The nonunion rate in 12 months was 6.5% in experimental group but 19.6% in control group(P<0.05). In 3, 6, 12 months postoperatively, VAS score and Lane-Sandhu score in experimental group had more significantly difference than them in control group. RSSS can intermittently provide dynamic mechanical load and stimulate callus formation, promote lower tibial bone union, reduce bone delayed union or nonunion rate. It is an adjuvant therapy for promoting bone union after lower tibial bone fracture.

  16. [APPLICATION OF V-Y ADVANCED SENSE-REMAINED POSTERIOR TIBIAL ARTERY PERFORATOR FLAP IN REPAIRING WOUND AROUND ANKLE].

    PubMed

    Tang, Xiujun; Wang, Bo; Wei, Zairong; Wang, Dali; Han, Wenjie; Zhang, Wenduo; Li, Shujun

    2015-12-01

    OBJECTIVE To explore the feasibility and effectiveness of V-Y advanced sense-remained posterior tibial artery perforator flap in repairing wound around the ankle. METHODS Between March 2012 and January 2015, 11 patients with wounds around the ankle were treated by V-Y advanced sense-remained posterior tibial artery perforator flap. There were 6 males and 5 females with a median age of 37 years (range, 21-56 years). The causes were traffic accident injury in 3 cases, thermal injury in 2 cases, burn in 2 cases, iatrogenic wounds in 2 cases, and local contusion in 2 cases. The disease duration ranged from 1 to 3 weeks (mean, 2 weeks). Injury was located at the medial malleolus in 4 cases, at the lateral malleolus in 3 cases, and at the heel in 4 cases. All had exposure of bone, tendon, or plate. The defect area ranged from 4 cmx2 cm to 5 cmx3 cm; the area of the flap ranged from 11 cmx4 cm to 15 cmx6 cm. Necrosis of distal flap occurred in 1 case after operation; re-operation to amputate the posterior tibial artery was given and the wound was repaired by proximal skin graft. Light necrosis of distal end was observed in 2 cases, and wound healed at 3 weeks after dressing. And other flaps successfully survived, and primary healing of wounds were obtained. The patients were followed up 6-24 months (mean, 11 months). The flaps were good in color, texture, and appearance. The ankle joint had normal activity. At last follow-up, 10 cases restored fine sense, and 1 case restored protective feeling with posterior tibial artery advanced flap after amputation. V-Y advanced sense-remained posterior tibial artery perforator flap has the advantages of reliable blood supply, simple operation, good appearance, and sensory recovery. Therefore, it is an ideal method to repair wound around the ankle.

  17. [Revision of Schatzker type Ⅵ tibial plateau fracture failure focus on the recovery of lower limb alignment].

    PubMed

    Cong, R J; Liu, J F; Jiang, Y; Dilixiati, Duolikun; Hou, X D; Zheng, L P

    2018-03-01

    Objective: To explore the influence of the lower extremity abnormal alignment and the joint surface, and to explore the surgical skills. Methods: Twenty-two cases of tibial plateau Schatzker Ⅵ fracture internal fixation failure revision from January 2012 to January 2017 in Department of Orthopedics, Shanghai 10(th) Hospital.One year follow-up after initial surgery to make sure of failure.Three-dimensional CT scan, radiography, infection index, gait analysis, knee joint ROM, femur tibia angle, tibial plateau tibial shaft angle and posterior slope if tibial plateau were observed. The medial approach and bi-planer osteotoma were used.Autogenous iliac bone graft, postoperative fast recovery channel were used.Follow-up point included preoperative and postoperative 7 days, 6 weeks, 3 months, and 6 months.Obvervational index included double lower limbs radiography, knee society score(KSS), complications such as infection, skin necrosis, joint main passive activity, double lower limbs alignment the last follow-up SF-36 scale.Rate was compared by χ(2) test, measurement data using paired sample t test.Correlation was analyzed by Pearson correlation regression testing. Results: Twenty-two patients received follow-up.KSS, more than 21 cases were benign, with good gait.One case was poor, with claudication gait.Not skin necrosis, no deep infection cases, 1 case get blisters 2 days postoperatively, and disappear after 5 days with detumescence and cold therapy.Whether restoring force line affect the KSS significantly(χ(2)=22.000, P =0.000). Knee joint ROM, SF-36 score, KSS and lower limb alignment were improved significantly. In different individual the articular surface and anatomical angle recovered greatly but the posterior slope angle was quite difference which has no correlation with KSS and SF-36 scale( P >0.01). Conclusions: Revision of Schatzker type Ⅵ tibial plateau fracture failure should focus on the recovery of lower limb alignment.moderate overcorrect bone

  18. Tibial coverage, meniscus position, size and damage in knees discordant for joint space narrowing – data from the Osteoarthritis Initiative

    PubMed Central

    Bloecker, K.; Guermazi, A.; Wirth, W.; Benichou, O.; Kwoh, C.K.; Hunter, D.J.; Englund, M.; Resch, H.; Eckstein, F.

    2013-01-01

    SUMMARY Introduction Meniscal extrusion is thought to be associated with less meniscus coverage of the tibial surface, but the association of radiographic disease stage with quantitative measures of tibial plateau coverage is unknown. We therefore compared quantitative and semi-quantitative measures of meniscus position and morphology in individuals with bilateral painful knees discordant on medial joint space narrowing (mJSN). Methods A sample of 60 participants from the first half (2,678 cases) of the Osteoarthritis Initiative cohort fulfilled the inclusion criteria: bilateral frequent pain, Osteoarthritis Research Society International (OARSI) mJSN grades 1–3 in one, no-JSN in the contra-lateral (CL), and no lateral JSN in either knee (43 unilateral mJSN1; 17 mJSN2/3; 22 men, 38 women, body mass index (BMI) 31.3 ± 3.9 kg/m2). Segmentation and three-dimensional quantitative analysis of the tibial plateau and meniscus, and semi-quantitative evaluation of meniscus damage (magnetic resonance imaging (MRI) osteoarthritis knee score – MOAKS) was performed using coronal 3T MR images (MPR DESSwe and intermediate-weighted turbo spin echo (IW-TSE) images). CL knees were compared using paired t-tests (between-knee, within-person design). Results Medial tibial plateau coverage was 36 ± 9% in mJSN1 vs 45 ± 8% in CL no-JSN knees, and was 31 ± 9% in mJSN2/3 vs 46 ± 6% in no-JSN knees (both P < 0.001). mJSN knees showed greater meniscus extrusion and damage (MOAKS), but no significant difference in meniscus volume. No significant differences in lateral tibial coverage, lateral meniscus morphology or position were observed. Conclusions Knees with medial JSN showed substantially less medial tibial plateau coverage by the meniscus. We suggest that the less meniscal coverage, i.e., less mechanical protection may be a reason for greater rates of cartilage loss observed in JSN knees. PMID:23220556

  19. Facility target insert shielding assessment

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mocko, Michal

    2015-10-06

    Main objective of this report is to assess the basic shielding requirements for the vertical target insert and retrieval port. We used the baseline design for the vertical target insert in our calculations. The insert sits in the 12”-diameter cylindrical shaft extending from the service alley in the top floor of the facility all the way down to the target location. The target retrieval mechanism is a long rod with the target assembly attached and running the entire length of the vertical shaft. The insert also houses the helium cooling supply and return lines each with 2” diameter. In themore » present study we focused on calculating the neutron and photon dose rate fields on top of the target insert/retrieval mechanism in the service alley. Additionally, we studied a few prototypical configurations of the shielding layers in the vertical insert as well as on the top.« less

  20. Tibial rotation under combined in vivo loading after single- and double-bundle anterior cruciate ligament reconstruction.

    PubMed

    Tsarouhas, Alexander; Iosifidis, Michael; Spyropoulos, Giannis; Kotzamitelos, Dimitrios; Tsatalas, Themistoklis; Giakas, Giannis

    2011-12-01

    To evaluate in vivo the differences in tibial rotation between single- and double-bundle anterior cruciate ligament (ACL)-reconstructed knees under combined loading conditions. An 8-camera optoelectronic system and a force plate were used to collect kinematic and kinetic data from 14 patients with double-bundle ACL reconstruction, 14 patients with single-bundle reconstruction, 12 ACL-deficient subjects, and 12 healthy control individuals while performing 2 tasks. The first included walking, 60° pivoting, and stair ascending, and the second included stair descending, 60° pivoting, and walking. The 2 variables evaluated were the maximum range of internal-external tibial rotation and the maximum knee rotational moment. Tibial rotation angles were not significantly different across the 4 groups (P = .331 and P = .851, respectively) or when side-to-side differences were compared within groups (P = .216 and P = .371, respectively) for the ascending and descending maneuvers, nor were rotational moments among the 4 groups (P = .418 and P = .290, respectively). Similarly, for the descending maneuver, the rotational moments were not significantly different between sides (P = .192). However, for the ascending maneuver, rotational moments of the affected sides were significantly lower by 20.5% and 18.7% compared with their intact counterparts in the single-bundle (P = .015) and double-bundle (P = .05) groups, respectively. High-intensity activities combining stair ascending or descending with pivoting produce similar tibial rotation in single- and double-bundle ACL-reconstructed patients. During such maneuvers, the reconstructed knee may be subjected to significantly lower rotational loads compared with the intact knee. Level III, retrospective comparative study. Copyright © 2011 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.