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Sample records for cemented femoral stem

  1. Complications With Long Cemented Stems in Proximal Femoral Replacement.

    PubMed

    Naik, Amish A; Lietman, Steven A

    2016-05-01

    This study attempted to determine whether patients undergoing cemented long-stem proximal femoral replacement had: (1) an increased short-term mortality rate; (2) greater intraoperative hemodynamic instability; (3) a greater need for resuscitation; and (4) a decreased risk of periprosthetic fracture. The current study reviewed intraoperative and short-term events related to clinical outcomes in 24 consecutive patients who were treated at a single institution over a 5-year period. These patients underwent primary long-stem (≥250 mm, n=13) vs short-stem (<250 mm, n=11) cemented proximal femoral replacement. Other than stem length, the 2 groups were not significantly different in terms of patient age, sex, height, weight, body mass index, diagnosis, or preoperative American Society of Anesthesiologists functional score. Primary outcomes were intraoperative death, blood loss, blood transfusions, fluid resuscitation, hypotension, oxygen desaturation, mortality up to 1 year, and need for revision surgery. At 1 year, a significantly increased mortality rate (77% vs 27%, P=.03) was noted in patients receiving long-stem vs short-stem arthroplasty. Patients who received longer stems also required more intraoperative blood transfusions and fluid resuscitation (P=.04) for greater hypotension (P=.04) and oxygen desaturation (P=.04). Two intraoperative deaths occurred in the long-stem group, and none occurred in the short-stem group. The findings suggest that there is an increased risk of intraoperative hemodynamic instability with long-stem vs short-stem proximal femoral replacement, with a need for greater resuscitative efforts and an increased risk of mortality at 1 year. [Orthopedics. 2016; 39(3):e423-e429.]. PMID:27064780

  2. Acrylic cement creeps but does not allow much subsidence of femoral stems.

    PubMed

    Verdonschot, N; Huiskes, R

    1997-07-01

    It has been suggested that the endurance of cemented femoral reconstructions in total hip arthroplasty is affected by the creep of acrylic cement, but it is not known to what extent cement creeps under loading conditions in vivo, or how this affects load transfer. We have simulated the long-term creep properties of acrylic cement in finite-element models of femoral stem constructs and analysed their effects. We investigated whether subsidence rates measured in vivo could be explained by creep of acrylic cement, and if polished, unbonded, stems accommodated creep better than bonded stems. Our findings showed that polished prostheses subsided only about 50 microm as a result of cement creep. The long-term prosthetic subsidence rates caused by creep of acrylic cement are therefore very small and do not explain the excessive migration rates which have sometimes been reported. Cement creep did, however, relax cement stresses and create a more favourable stress distribution at the interfaces. These trends were found around both the bonded and unbonded stems. Our results did not confirm that polished, unbonded, stems accommodated creep better than bonded stems in terms of cement and interface stress patterns. PMID:9250762

  3. The influence of cement mantle thickness and stem geometry on fatigue damage in two different cemented hip femoral prostheses.

    PubMed

    Ramos, A; Simões, J A

    2009-11-13

    Experimental models can be used for pre-clinical testing of cemented and other type of hip replacements. Total hip replacement (THR) failure scenarios include, among others, cement damage accumulation and the assessment of accurate stress and strain magnitudes at the cement mantle interfaces (stem-cement and cement-bone) can be used to predict mechanical failure. The aseptic loosening scenario in cemented hip replacements is currently not fully understood, and methods of evaluating medical devices must be developed to improve clinical performance. Different results and conclusions concerning the cement micro-cracking mechanism have been reported. The aim of this study was to verify the in vitro behavior of two cemented femoral stems with respect to fatigue crack formation. Fatigue crack damage was assessed at the medial, lateral, anterior and posterior sides of the Lubinus SPII and Charnley stems. All stems were loaded and tested in stair climbing fatigue loading during one million cycles at 2 Hz. After the experiments each implanted synthetic femur was sectioned and analyzed. We observed more damage (cracks per area) for the Lubinus SPII stem, mainly on the proximal part of the cement mantle. The micro-cracking formation initiated in the stem-cement interface and grew towards the direction of cortical bone of the femur. Overall, the cement-bone interface seems to be crucial for the success of the hip replacement. The Charnley stem provoked more damage on the cement-bone interface. A failure index (maximum length of crack/maximum thickness of cement) considered was higher for the cement-stem interface of the Lubinus SPII stem. For a cement mantle thickness higher than 5 mm, cracking initiated at the cement-bone interface and depended on the opening canal process (reaming procedure and instrumentation). The analysis also showed that fatigue-induced damage on the cement mantle, increasing proximally, and depended on the axial position of the stem. The cement

  4. Dislodgement of a cemented exeter femoral stem during closed manipulative reduction of a dislocated total hip replacement

    PubMed Central

    Rajeev, Aysha; Mohamed, Abdalla; Shaikh, Mazharuddin; Banaszkiewicz, Paul

    2016-01-01

    Introduction The incidence of cemented femoral stem migration and dislodgement even though has been described is extremely unusual. There is a high chance of polished femoral stem displacement happening while trying to reduce a dislocated total hip replacement by closed measures. Presentation of the case A 73 year old lady who had an Exeter cemented total hip replacement about two weeks back was admitted from Accident and Emergency with a dislocation. During the closed manipulative reduction under general anaesthesia it was noted that the femoral stem has dislodged from the canal. She underwent revision of the total hip replacement with good outcome. Discussion Femoral stem dislodgement occurs in total hip replacement if polished stem or inadequate cementing of the collar is carried out. Conclusion Gentle manipulative reduction under general anaesthesia of dislocated total hip replacement should be carried out if the polished femoral stem is used. PMID:27060643

  5. Influence of femoral stem surface finish on the apparent static shear strength at the stem-cement interface.

    PubMed

    Zhang, H; Brown, L T; Blunt, L A; Barrans, S M

    2008-01-01

    The stem-cement interface has long been implicated in failure of cemented total hip replacement. Much research has been performed to study the factors affecting the bond strength between the femoral stem and the bone cement. The present study aims to further investigate the influence of femoral stem surface finish on the apparent static shear strength at the stem-cement interface through a series of pull out tests, where stainless steel rods are employed to represent the femoral stem. The results demonstrated that there was a general tendency for the apparent static shear strength to be increased with the rise of surface roughness. The polished and glass bead-blasted rods illustrated a slip-stick-slip failure whereas the shot-blasted and grit-blasted rods displayed gross interface failure. Following pull out test, cement transfer films were detected on the polished rods, and there was cement debris adhered to the surface of the grit-blasted rods. Micropores, typically 120 mum in diameter, were prevalent in the cement surface interfaced with the polished rods, and the cement surfaces in contact with the shot-blasted and grit-blasted rods were greatly damaged. There was also evidence of metal debris embedding within the cement mantle originating from the tests of the grit-blasted rods, indicating an extremely strong mechanical interlocking at the interface. In summary, this present research demonstrated that the grit-blasted rods with the highest surface roughness were the best in terms of apparent static shear strength. However, it seemed to be most applicable only to the stem designs in which mechanical interlocking of the stem in the initial fixed position was essential. PMID:19627775

  6. Cement-in-cement femoral revisions using a specially designed polished short revision stem; 24 consecutive stems followed for five to seven years.

    PubMed

    te Stroet, Martijn A J; Moret-Wever, Sander G; de Kam, Daniël C J; Gardeniers, Jean W M; Schreurs, B Willem

    2014-01-01

    Femoral cement-in-cement revisions are attractive if the cement bone mantle is well fixed. However, most available cemented stems are too long to fit in the existing cement mantle. We evaluated the medium-term outcomes of the 125 mm short tapered polished stem (Exeter Short Revision Stem (SRS)) with a 44 mm offset specifically designed to facilitate cement-in-cement revisions of hip arthroplasties. The Exeter SRS was clinically and radiographically evaluated in 24 consecutive femoral cement-in-cement revisions (11 men, 13 women) between July 2005 and February 2008 after a mean follow-up of six years (5-7). The mean age at operation was 67 years (54-83). No hip was lost to follow-up, but two patients (two hips) died. None of the deaths were related to the surgery. Kaplan Meier survival analysis was performed. Four femoral components (17%) were removed for septic loosening after a mean of 2.4 years (0.8-4.9). Three of these hips were revised again in a two-stage revision, and one was converted to a permanent excision arthroplasty. The probability of survival with re-revision for any reason was 82% (95% CI: 58-93) and survivorship with aseptic loosening as the endpoint was 100% at six years. There were no additional radiological failures. The Exeter Short Revision Stem is a valuable option for simplifying cement-in-cement revisions. Despite the short stem length, at mid-term there were no signs of instability or aseptic loosening. PMID:24970322

  7. Metal debris concentrations in soft tissues adjacent to loosened femoral stems is higher in uncemented than cemented implants

    PubMed Central

    2014-01-01

    Background There are still many questions related to aseptic femoral stem loosening. Systemic and local immune responses to the implanted “foreign body” is one of the reasons for loosening. The purpose of the study was to measure metal ion concentration (Ti, Co, Cr, Mo, Ni, Al) around loosened femoral stems and compare their levels around uncemented and cemented implants. Methods This paper reports 50 hips operated for isolated stem loosening, in 50 patients at the mean age of 57 years (from 21 to 87). There were 25 cemented (Co,Cr29,Mo,Ni) and 25 uncemented (Ti, Al) stems. The mean follow-up from primary hip replacement to revision was 10.1 years (from 0.5 to 17). During the procedure, scar tissue around the stem was taken for analysis of metal ions. Results The concentrations of titanium and aluminium in soft tissues around uncemented loosened stems were higher than cemented ones (p < 0.001, p < 0.001 respectively). However, no statistically significant differences were observed between both types of stems in terms of ions of the metal of which cemented implants had been made of (Co, Cr, Mo, Ni). Conclusions In soft tissue around a loosened stem, the concentrations of metal ions from implants are much higher in case of uncemented stems than of cemented ones. Metal ions from vitalium femoral heads were found around uncemented stems in similar values to cemented streams. PMID:25098913

  8. The effect of adding tobramycin to Simplex P cement on femoral stem micromotion as measured by radiostereometric analysis

    PubMed Central

    2012-01-01

    Background Previous in vitro research on addition of antibiotics to bone cement has found no statistically significant deterioration in mechanical properties. However, no clinical studies have compared the performance of tobramycin-laden bone cement with that of standard bone cement (Simplex P). Patients and Methods 23 patients (25 hips) were randomized to receive an Exeter (Stryker Orthopaedics) femoral stem cemented with either Simplex P (standard) or Simplex T (tobramycin-laden) cement. There were 2 years of follow-up, with scheduled radiostereometric (RSA) examinations. Results All stems migrated distally and showed some degree of retroversion. No clinically significant differences in stem subsidence or retroversion were found between the Simplex T and Simplex P cement groups after 2 years. Overall subsidence was less than in previous studies, probably due to a postponed initial post-surgical examination. Rates of subsidence in both cement groups were consistent with those from previous studies of Exeter stems. Interpretation Subsidence of the femoral stem after 2 years was similar in the Simplex T (tobramycin-laden) and Simplex P (standard) groups. PMID:22248163

  9. Direct evidence of "damage accumulation" in cement mantles surrounding femoral hip stems retrieved at autopsy: cement damage correlates with duration of use and BMI.

    PubMed

    Race, A; Miller, M A; Izant, T H; Mann, K A

    2011-09-01

    The "damage accumulation" phenomenon has not been quantitatively demonstrated in clinical cement mantles surrounding femoral hip stems. We stained transverse sections of 11 postmortem retrieved femoral hip components fixed with cement using fluorescent dye-penetrant and quantified cement damage, voids, and cement-bone interface gaps in epifluorescence and white light micrographs. Crack density (Cr.Dn), crack length-density (Cr.Ln.Dn), porosity, and cement-bone interface gap fraction (c/b-gap%) were calculated, normalized by mantle area. Multiple regression tests showed that cement damage (Cr.Ln.Dn. & Cr.Dn.) was significantly positively correlated (r(2)=0.98, p<0.001) with "duration of use" and body mass index ("BMI") but not cement mantle "porosity". There were significant interactions: "duration of use"*"BMI" was strongly predictive (p<0.005) of Cr.Dn.; and "duration of use"*"porosity" was predictive (p=0.04) of Cr.Ln.Dn. Stem related cracks accounted for approximately one fifth of Cr.Dn and one third of Cr.Ln.Dn. The mean c/b-gap% was 13.8% but it did not correlate (r(2)=0.01, p=0.8) with duration of use. We concluded that duration-dependent fatigue damage accumulation occurred during in vivo use. BMI strongly influenced cement crack length and the rate of new crack formation over time. Voids did not increase the rate of crack initiation but appeared to have promoted crack growth over time. Although not progressive, substantial bone resorption at the cement-bone interface appeared to be common. PMID:21802085

  10. Interface abrasion between rough surface femoral stems and PMMA cement results in extreme wear volumes--a retrieval study and failure analysis.

    PubMed

    Buchhorn, Gottfried Hans; Bersebach, Petra; Stauch, Tilo; Schultz, Wolfgang; Köster, Georg

    2015-01-01

    During the loosening cascade of cemented rough femoral stems, the destruction of the mantle and the production of cement and metal wear debris occur after the loss of constraint at the interface. Two-dimensional (2D) measurements (light microscopy based morphometry on fragments of mantles and vertical scanning interferometry of femoral stems) permitted mathematical 3D-extrapolations to estimate the wear volumes. Fragments of the cement mantles available lost volumes from 0.85 mm(3) to 494.10 mm(3) (median amount of bone cement wear = 178,426 mg). The harder metal surfaces lost between 1.459 mm(3) and 5.688 mm(3) of material (the median amount of metal wear per surface = 1.504 mg/100 mm(2)). Compared to the loss of material due to the fretting of stems, the abrasion of metal, and cement in defective cement mantles produced wear volumes sufficiently high to induce osteolysis. Though the design of the femoral stem and the handling of bone cement do not represent contemporary design and clinical practice, respectively, an extremely high number of joint replacements still in daily use may be impacted by this study because of possible predicted failures. Once the processes of fragmentation, abrasion, and osteolysis have been realized, the time until revision surgery should not be unduly prolonged. PMID:24820132

  11. A valuable technique for femoral stem revision in total hip replacement: The in-cement revision - A case series and technical note.

    PubMed

    McDougall, C J; Yu, J; Calligeros, K; Crawford, R; Howie, C R

    2016-12-01

    Revision of a cemented femoral stem can be a challenging procedure. We present a series of cases utilising the "In-cement" revision, whereby the same size stem is introduced into the original cement mantle, without additional cementing. It requires a stable cement mantle in the correct version. We describe the technique and present a review of 23 revision total hip replacements performed over a 5 year period. At average follow-up of 67 months (12-128 months), the overall survivorship was 91.3% with no patient requiring re-revision for stem loosening or mechanical failure. Two patients required re-revision for infection and one of those patients is now deceased. No further operations were required in 21 patients. The "In-cement" revision can be a valuable technique for the revision arthroplasty surgeon. Early results suggest this is a safe and effective technique in the appropriate patient. PMID:27408507

  12. Analysis of Femoral Components of Cemented Total Hip Arthroplasty

    NASA Astrophysics Data System (ADS)

    Singh, Shantanu; Harsha, A. P.

    2015-10-01

    There have been continuous on-going revisions in design of prosthesis in Total Hip Arthroplasty (THA) to improve the endurance of hip replacement. In the present work, Finite Element Analysis was performed on cemented THA with CoCrMo trapezoidal, CoCrMo circular, Ti6Al4V trapezoidal and Ti6Al4V circular stem. It was observed that cross section and material of femoral stem proved to be critical parameters for stress distribution in femoral components, distribution of interfacial stress and micro movements. In the first part of analysis, designs were investigated for micro movements and stress developed, for different stem materials. Later part of the analysis focused on investigations with respect to different stem cross sections. Femoral stem made of Titanium alloy (Ti6Al4V) resulted in larger debonding of stem at cement-stem interface and increased stress within the cement mantle in contrast to chromium alloy (CoCrMo) stem. Thus, CoCrMo proved to be a better choice for cemented THA. Comparison between CoCrMo femoral stem of trapezium and circular cross section showed that trapezoidal stem experiences lesser sliding and debonding at interfaces than circular cross section stem. Also, trapezium cross section generated lower peak stress in femoral stem and cortical femur. In present study, femur head with diameter of 36 mm was considered for the analysis in order to avoid dislocation of the stem. Also, metallic femur head was coupled with cross linked polyethylene liner as it experiences negligible wear compared to conventional polyethylene liner and unlike metallic liner it is non carcinogenic.

  13. Cemented femoral fixation: the North Atlantic divide.

    PubMed

    Murray, David W

    2011-09-01

    In the United Kingdom, more cemented than cementless stems are implanted, whereas in North America, few cemented stems are implanted. This is primarily because cemented stems have not performed well in North America, whereas they have in the United Kingdom, as different designs have been used. The majority of cemented stems used in the United Kingdom are polished, collarless, and tapered. These are forgiving, as they subside within the cement mantle and compress the cement and stabilize the interface. They perform well in both young and active patients and elderly patients. They also do well in osteoporotic bone, with deformity, or with suboptimal cementing techniques. As the position of the stem can be varied, it is simple to achieve appropriate leg length, offset, and version. Cement can be used to deliver antibiotics locally. If revision is necessary, it is relatively straightforward. Cement has numerous advantages that outweigh the main disadvantage of an extended operating time. PMID:21902131

  14. Mid-term study of bone remodeling after femoral cemented stem implantation: comparison between DXA and finite element simulation.

    PubMed

    Herrera, Antonio; Rebollo, Sarai; Ibarz, Elena; Mateo, Jesús; Gabarre, Sergio; Gracia, Luis

    2014-01-01

    This five-year prospective study was designed to investigate periprosthetic bone remodeling associated with two cemented stem models, ABG-II (Stryker) and VerSys (Zimmer), randomly implanted in patients older than 75 years. The sample consisted of 64 cases (32, ABG-II; 32, VerSys). Inclusion criterion was diagnosis of osteoarthritis recommended for cemented total hip arthroplasty. Besides clinical study, Finite Element (FE) simulation was used to analyze biomechanical changes caused by hip arthroplasty. Bone Mineral Density (BMD) measurements showed a progressive increase in bone mass throughout the entire follow-up period for both stems, well correlated with FE results except in Gruen zones 4, 5, 6 for ABG-II and in zones 4, 5 for VerSys, denoting that remodeling in those zones does not depend on mechanical factors but rather on biological or physiological ones. PMID:23725926

  15. A critical assessment of proximal macrotexturing on cemented femoral components.

    PubMed

    Duffy, G P; Muratoglu, O K; Biggs, S A; Larson, S L; Lozynsky, A J; Harris, W H

    2001-12-01

    We analyzed the cement-metal interface of 3 different types of femoral components that had proximal macrotexturing after in vitro insertion and after fatigue testing designed to produce debonding and micromotion. These components were compared with clinical retrieval specimens. The cement did not flow into the macrotexturing; rather, hollow, brittle volcanoes or calderas were formed. These fragile protrusions of cement become worn down or abraded by debonded components. This abrasion of cement may contribute to the early and aggressive osteolysis seen in some of these early failures with proximal macrotextured components. The formation of these volcanos and calderas can be aborted by placing bone-cement onto the macrotexturing before stem insertion. This simple technique allows the macrotexturing to be filled with cement. PMID:11742450

  16. Micromotion of cemented and uncemented femoral components.

    PubMed

    Burke, D W; O'Connor, D O; Zalenski, E B; Jasty, M; Harris, W H

    1991-01-01

    We evaluated the initial stability of cemented and uncemented femoral components within the femoral canals of cadaver femurs during simulated single limb stance and stair climbing. Both types were very stable in simulated single limb stance (maximum micromotion of 42 microns for cemented and 30 microns for uncemented components). However, in simulated stair climbing, the cemented components were much more stable than the uncemented components (76 microns as against 280 microns). There was also greater variation in the stability of uncemented components in simulated stair climbing, with two of the seven components moving 200 microns or more. Future implant designs should aim to improve the initial stability of cementless femoral components under torsional loads; this should improve the chances of bony ingrowth. PMID:1991771

  17. Cement-in-cement revision for selected Vancouver Type B1 femoral periprosthetic fractures: a biomechanical analysis.

    PubMed

    Brew, Christopher J; Wilson, Lance J; Whitehouse, Sarah L; Hubble, Matthew J W; Crawford, Ross W

    2013-03-01

    The aim of this study was to perform a biomechanical analysis of the cement-in-cement (c-in-c) technique for fixation of selected Vancouver Type B1 femoral periprosthetic fractures and to assess the degree of cement interposition at the fracture site. Six embalmed cadaveric femora were implanted with a cemented femoral stem. Vancouver Type B1 fractures were created by applying a combined axial and rotational load to failure. The femora were repaired using the c-in-c technique and reloaded to failure. The mean primary fracture torque was 117 Nm (SD 16.6, range 89-133). The mean revision fracture torque was 50 Nm (SD 16.6, range 29-74), which is above the torque previously observed for activities of daily living. Cement interposition at the fracture site was found to be minimal. PMID:23146585

  18. The importance of a thick cement mantle depends on stem geometry and stem-cement interfacial bonding.

    PubMed

    Caruana, J; Janssen, D; Verdonschot, N; Blunn, G W

    2009-04-01

    The thickness of the cement mantle around the femoral component of total hip replacements is a contributing factor to aseptic loosening and revision. Nevertheless, various designs of stems and surgical tooling lead to cement mantles of different thicknesses. Opinion is divided on whether a thick mantle enhances implant longevity. This study investigates the effect of cement mantle thickness on accumulated damage in the cement, and how this is influenced by the presence or absence of a proximal collar and on whether the stem-cement interface remains bonded. Three-dimensional finite element simulations incorporating creep and non-linear damage accumulation were performed to investigate cracking in the cement mantles around Stanmore Hips under physiologically informed stair-climbing and gait loads. Cement mantle thickness, stem-cement interfacial bonding, and collar design were varied to assess the interactive effects of these parameters. In all cases, damage levels were three to six times higher when the stem-cement interface remained bonded. Cement mantle thickness had little effect on cement damage accumulation around debonded collared stems but was critical in both bonded and collarless cases, where a thicker mantle reduced cement cracking. Damage around a smooth debonded stem with a collar is thus much less sensitive to cement thickness than around bonded or collarless stems. PMID:19405437

  19. Conservative femoral stem revision: avoiding therapeutic escalation.

    PubMed

    Pinaroli, Alban; Lavoie, Frédéric; Cartillier, Jean-Claude; Neyret, Philippe; Selmi, Tarik Ait Si

    2009-04-01

    A conservative approach to femoral revision is assessed. We report on 41 femoral revisions using an extensively coated hydroxyapatite primary femoral stem. Clinical, operative, and radiological data were gathered. Harris hip scores increased from 65/100 to 90/100 at the minimal follow-up of 1 year (P < .05). All stems showed signs of osseous integration. No significant migration was measured. No patient had to be reoperated because of problems related to the stem. Good results are reported for femoral revision with Paprosky type I and II bone defects with no significant difference between the 2 subgroups, hereby proving that conservative femoral revision is a reasonable treatment alternative. Reproducible results with such a technique may bring surgeons to be more aggressive when noticing early signs of femoral loosening. PMID:18534426

  20. Stem–Cement Porosity May Explain Early Loosening of Cemented Femoral Hip Components: Experimental-Computational In Vitro Study

    PubMed Central

    Mann, Kenneth A.; Damron, Leatha A.; Miller, Mark A.; Race, Amos; Clarke, Michael T.; Cleary, Richard J.

    2007-01-01

    A combination of laboratory experiment and computational simulation was performed to assess the role of interface porosity on stem migration. The early motion of in vitro prepared cemented femoral components was measured during application of cyclic stair climbing loads. Following testing, transverse sections were obtained and the distribution of pores at the stem–cement interface was determined. Finite element models of cemented stem constructs were developed and a scheme was implemented to randomly assign pores to the stem–cement interface. For a series of 14 in vitro prepared components, pore fractions at the stem–cement interface ranged from 23% to 67%. The majority of pores at the stem–cement interface were less than 1 mm in length with a mean length of 1.27 ± 2.7 mm and thickness of 0.12 ± 0.11 mm. For stems with large pore fractions, pores tended to coalesce in longer extended gaps over the stem surface. Finite element and experimental models both revealed strong positive correlations (r2 = 0.55–0.72; p < 0.0001) between stem–cement pore fraction and stem internal rotation, suggesting that the presence and extent of pores could explain the early motion of the stems. There was an increased volume of cement at risk of fatigue failure with increasing stem migration. Pore fractions greater than 30% resulted in large increases in stem internal rotation, suggesting that attempts to maintain surface porosity at or below this level may be desirable to minimize the risk of clinical loosening. PMID:17149748

  1. 21 CFR 888.3360 - Hip joint femoral (hemi-hip) metallic cemented or uncemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Hip joint femoral (hemi-hip) metallic cemented or... Hip joint femoral (hemi-hip) metallic cemented or uncemented prosthesis. (a) Identification. A hip joint femoral (hemi-hip) metallic cemented or uncemented prosthesis is a device intended to be...

  2. 21 CFR 888.3360 - Hip joint femoral (hemi-hip) metallic cemented or uncemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Hip joint femoral (hemi-hip) metallic cemented or... Hip joint femoral (hemi-hip) metallic cemented or uncemented prosthesis. (a) Identification. A hip joint femoral (hemi-hip) metallic cemented or uncemented prosthesis is a device intended to be...

  3. 21 CFR 888.3360 - Hip joint femoral (hemi-hip) metallic cemented or uncemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Hip joint femoral (hemi-hip) metallic cemented or... Hip joint femoral (hemi-hip) metallic cemented or uncemented prosthesis. (a) Identification. A hip joint femoral (hemi-hip) metallic cemented or uncemented prosthesis is a device intended to be...

  4. Using “Sub-cement” to simulate the long-term fatigue response of cemented femoral stems in a cadaver model: could a novel pre-clinical screening test have caught the Exeter matte problem?

    PubMed Central

    Race, Amos; Miller, Mark A.; Mann, Kenneth A.

    2010-01-01

    Previously, we formulated cement with degraded fatigue properties (sub-cement) to simulate long-term fatigue in short-term cadaver tests. The present study determined the efficacy of sub-cement in a `pre-clinical' test of a design change with known clinical consequences: the “polished” to “matte” transition of the Exeter stem (revision rates were twice as high for matte stems). Contemporary stems were bead-blasted to give Ra=1micron (matte finish). Matte and polished stems were compared in cadaver pairs under stair-climbing loads (3 pairs size-1, 3 pairs size-3). Stem micromotion was monitored during loading. Post-test, transverse sections were examined for cement damage. Cyclic retroversion decreased for polished stems but increased for matte stems (p<0.0001). Implant size had a substantial effect: retroversion of (larger) size-3 stems was half that of size-1 stems and polished size-3 stems subsided 2½ times more than the others. Cement damage measures were similar and open through-cracks occurred around both stems of two pairs. Stem retroversion within the mantle resulted in stem-cement gaps of 50–150microns. Combining information on cyclic motion, cracks, and gaps, we concluded that this test `predicted' higher revision rates for matte stems (it also implied that polished size-3 stems might be superior to size-1). PMID:20476506

  5. Bilateral Femoral Nutrient Foraminal Cement Penetration during Total Hip Arthroplasty

    PubMed Central

    Coomber, Ross; Bhumbra, Rej S; Marston, Robert

    2012-01-01

    Introduction: Cement pressurisation is important for the insertion of both the acetabular and femoral components during Total Hip Arthroplasty (THA). Secondary to pressurization the rare phenomenon of unilateral cement incursion into the nutrient foramen has previously been reported. No bilateral case has been reported to date. This has implications both for misdiagnosis of periprosthetic fractures and for medico-legal consequences due to a presumed adverse intra-operative event. Case Report: We present a case report of a 59 year old, caucasian female who underwent staged bilateral cemented Stanmore THA. The post-operative radiographs demonstrate evidence of bilateral nutrient foramen penetration intra-operatively by standard viscosity cement. The patient suffered no adverse consequences. Conclusions: In summary, cement extravasation into the nutrient foramen is an important differential to be considered in presence of posterior-medial cement in the diaphysis of femur following THA. This requires no further intervention and has no effect on the outcome.

  6. A modified technique to extract fractured femoral stem in revision total hip arthroplasty: A report of two cases

    PubMed Central

    Akrawi, Hawar; Magra, Merzesh; Shetty, Ajit; Ng, Aaron

    2014-01-01

    INTRODUCTION The removal of well-fixed broken femoral component and cement mantle can be extremely demanding, time consuming and potentially damaging to the host bone. Different methods have been described to extract broken femoral stem yet this remains one of the most challenging prospect to the revision hip surgeon. PRESENTATION OF CASE The authors present two cases underwent a modified sliding cortical window technique utilising a tungsten carbide drill, Charnley pin retractor and an orthopaedic mallet to aid extraction of a fractured cemented femoral stem in revision total hip arthroplasty. DISCUSSION The modified technique offers a simple and controlled method in extracting a well fixed fractured cemented femoral stem. It has the advantage of retaining the cement mantle with subsequent good seal of the femoral cortical window secured with cable ready system. Furthermore, tungsten carbide drill bit and Charnley pin retractor are relatively readily available to aid the extraction of the broken stem. Finally, it yields the option of implanting a standard femoral stem and obviates the need for bypassing the cortical window with long revision femoral component. CONCLUSION Fractured femoral stem is a rare yet a complex and very demanding prospect to both patients and hip surgeons. The sliding cortical window technique utilising tungsten carbide drill and Charnley pin retractor is technically easy and most importantly; preserves host bone stock with cement-in-cement revision hip arthroplasty. We believe this technique can be added to the armamentarium of revision hip surgeon when faced with the challenge of extracting a fractured cemented femoral stem. PMID:24858980

  7. A new design of cemented stem using functionally graded materials (FGM).

    PubMed

    Hedia, H S; Aldousari, S M; Abdellatif, A K; Fouda, N

    2014-01-01

    One of the most frequent complications of total hip replacement (THR) is aseptic loosening of femoral component which is primarily due to changes of post-operative stress distribution pattern with respect to intact femur. Stress shielding of the femur is known to be a principal factor in aseptic loosening of hip replacements. Many designers show that a stiff stem shields the surrounding bone from mechanical loading causing stress shielding. Others show that reducing stem stiffness promotes higher proximal interface shear stress which increases the risk of proximal interface failure. Therefore, the task of this investigation is to solve these conflicting problems appeared in the cemented total hip replacement. The finite element method and optimization technique are used in order to find the optimal stem material which gives the optimal available stress distribution between the proximal medial femoral bone and the cement mantle interfaces. The stem is designed using the concept of functionally graded material (FGM) instead of using the conventional most common used stem material. The results showed that there are four feasible solutions from the optimization runs. The best of these designs is to use a cemented stem graded from titanium at the upper stem layer to collagen at the lower stem layer. This new cemented stem design completely eliminates the stress shielding problem at the proximal medial femoral region. The stress shielding using the cemented functionally graded stem is reduced by 98% compared to titanium stem. PMID:24840196

  8. Cemented versus uncemented arthroplasty in patients with a displaced fracture of the femoral neck: a randomised controlled trial.

    PubMed

    Inngul, C; Blomfeldt, R; Ponzer, S; Enocson, A

    2015-11-01

    The aim of this randomised controlled study was to compare functional and radiological outcomes between modern cemented and uncemented hydroxyapatite coated stems after one year in patients treated surgically for a fracture of the femoral neck. A total of 141 patients aged > 65 years were included. Patients were randomised to be treated with a cemented Exeter stem or an uncemented Bimetric stem. The patients were reviewed at four and 12 months. The cemented group performed better than the uncemented group for the Harris hip score (78 vs 70.7, p = 0.004) at four months and for the Short Musculoskeletal Function Assesment Questionnaire dysfunction score at four (29.8 vs 39.2, p = 0.007) and 12 months (22.3 vs 34.9, p = 0.001). The mean EQ-5D index score was better in the cemented group at four (0.68 vs 0.53, p = 0.001) and 12 months (0.75 vs 0.58, p = < 0.001) follow-up. There were nine intra-operative fractures in the uncemented group and none in the cemented group. In conclusion, our data do not support the use of an uncemented hydroxyapatite coated stem for the treatment of displaced fractures of the femoral neck in the elderly. PMID:26530648

  9. Fracture of the cemented femoral component following hemiarthroplasty in physically active patient: A case report

    PubMed Central

    Cankaya, Deniz; Yoldas, Burak; Yılmaz, Serdar; Tecirli, Ali; Ozkurt, Bulent

    2015-01-01

    Introduction: Fracture of the femoral stem following hip arthroplasty has become very rare since the developments in modern prosthetic designs. Prevention by identifying the risk factors is the best way to overcome these complex problems, as treatment is difficult. Case Report: Femoral component fracture after cemented hemiarthroplasty in a physically active 64-year-old, male patient is reported in this present article. Conclusion: The present case emphasizes the importance of preserving the joint after hip fracture and avoidance of using mono block prosthesis in younger patients. If the patient is physically active, he/she should be advised to limit her/his daily activities to moderate intensity after hemiarthroplasty surgery. PMID:27299090

  10. 21 CFR 888.3360 - Hip joint femoral (hemi-hip) metallic cemented or uncemented prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... uncemented prosthesis. 888.3360 Section 888.3360 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Hip joint femoral (hemi-hip) metallic cemented or uncemented prosthesis. (a) Identification. A hip joint femoral (hemi-hip) metallic cemented or uncemented prosthesis is a device intended to be...

  11. 21 CFR 888.3360 - Hip joint femoral (hemi-hip) metallic cemented or uncemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... uncemented prosthesis. 888.3360 Section 888.3360 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Hip joint femoral (hemi-hip) metallic cemented or uncemented prosthesis. (a) Identification. A hip joint femoral (hemi-hip) metallic cemented or uncemented prosthesis is a device intended to be...

  12. Mechanical properties of femoral cortical bone following cemented hip replacement.

    PubMed

    Ni, G X; Lu, W W; Chiu, P K Y; Wang, Y; Li, Z Y; Zhang, Y G; Xu, B; Deng, L F; Luk, K D K

    2007-11-01

    Femoral bone remodeling following total hip replacement is a big concern and has never been examined mechanically. In this study, six goats underwent unilateral cemented hip hemiarthroplasty with polymethyl methacrylate (PMMA) bone cement. Nine months later animals were sacrificed, and the femoral cortical bone slices at different levels were analysed using microhardness testing and microcomputed tomography (micro-CT) scanning. Implanted femurs were compared to contralateral nonimplanted femurs. Extensive bone remodeling was demonstrated at both the proximal and middle levels, but not at the distal level. Compared with the nonimplanted side, significant decreases were found in the implanted femur in cortical bone area, bone mineral density, and cortical bone hardness at the proximal level, as well as in bone mineral density and bone hardness at the middle level. However, no significant difference was observed in either variable for the distal level. In addition, similar proximal-to-distal gradient changes were revealed both in cortical bone microhardness and bone mineral density. From the mechanical point of view, the results of the present study suggested that stress shielding is an important mechanical factor associated with bone adaptation following total hip replacement. PMID:17506504

  13. In vitro measurement of strain in the bone cement surrounding the femoral component of total hip replacements during simulated gait and stair-climbing.

    PubMed

    O'Connor, D O; Burke, D W; Jasty, M; Sedlacek, R C; Harris, W H

    1996-09-01

    The strains in the cement mantle surrounding the cemented femoral component of a total hip replacement were measured in vitro, using strain gauges embedded within the cement mantle adjacent to the femoral component in femurs from cadavers under physiologic loads simulating both single-limb stance and stair-climbing. Cement strains in the most proximal portion of the cement mantle were measured with and without full contact of the collar of the femoral stem on the cortex of the medial portion of the femoral neck during both loading conditions. To our knowledge, these are the first studies to contrast by direct measurement the strain profile in the cement mantle of a cemented femoral component under simulated stair-climbing with that occurring under simulated single-limb stance. They extend the findings from finite element analyses and from clinical specimens retrieved at autopsy in identifying those regions of the cement mantle most likely to fail. At two specific foci, the magnitude of the strain in the cement mantle approaches values that could lead to early fatigue failure of the cement. The two regions in which the strains were highest (greater than 1,000 microstrain) were the most proximal portions of the cement mantle and near the tip of the femoral component. Although these two regions are recognized areas of high strain and also common sites of cement debonding and cement mantle failure, the strain-gauge studies showed that the magnitude of cement strains in the proximal portion of the cement mantle were highest during stair-climbing; in contrast, high strains at the tip region occurred in both gait and stair-climbing. Contact between the collar and the medial portion of the femoral neck reduced the strain in the proximal portion of the cement mantle not only in single-limb stance but in stair-climbing as well. The level of strain recorded in these studies for a simulated person weighing 115 pounds (52 kg) could lead to cement fracture during extended in

  14. The Exeter femoral stem continues to migrate during its first decade after implantation

    PubMed Central

    2012-01-01

    Background Due to its collarless, double-tapered polished design, the Exeter femoral stem is known to migrate distally in the first 5 years after implantation. However, its long-term migration pattern has not been investigated. Patients and methods 39 consecutive patients (41 total hip arthroplasties) received a cemented Exeter stem and had prospective clinical and RSA follow-up. Patients were evaluated postoperatively at 6, 12, 26, and 52 weeks, and annually thereafter. Short-term results have been reported. In this study, the mean length of follow-up was 9.4 years (SD 3.2 years). No patients were lost to follow-up. 15 patients died during follow-up. Results No stems were revised. In 4 stems, fractures of the cement mantle were noted within the first 3 postoperative years. In 3 stems, this resulted in a complete circumferential cement mantle discontinuity. For the 37 well-performing stems, continuous but small migration was measured between 2 and 12 years of follow-up. Continued subsidence of 0.08 mm/year (95% CI: 0.05–0.12, p < 0.001) was seen in combination with continued rotation in retroversion of 0.07°/year (95% CI: 0.02–0.12, p = 0.01). At 10 years of follow-up, mean subsidence was 2.1 (SD 1.2) mm and mean retroversion was 1.8° (SD 2.0). Two-thirds of this occurred during the first 2 postoperative years. In the 3 stems with a complete circumferential cement fracture, a sudden and disproportionately high increase in subsidence was measured in the time period of occurrence. Interpretation The Exeter femoral stem continues to migrate during the first decade after implantation. Absolute stability is not required for good long-term survival if this is compatible with the design of the implant. PMID:22401676

  15. Mechanical implications of interfacial defects between femoral hip implants and cement: a finite element analysis of interfacial gaps and interfacial porosity.

    PubMed

    Scheerlinck, T; Broos, J; Janssen, D; Verdonschot, N

    2008-10-01

    Two types of defect between femoral hip implants and cement have been identified. Interfacial porosity arises from cement shrinkage during curing and presents as pores randomly located along the stem. Interfacial gaps are much larger stem-cement separations caused by air introduced during stem insertion. To investigate the mechanical consequences of both types of defect, a finite element analysis model was created on the basis of a computed tomography image of a Charnley-Kerboul stem, and alternating torsional and transverse loads were applied. The propagation of fatigue cracks within the cement and the rotational stability of the stem were assessed in models simulating increasing amounts of interfacial gaps and pores. Anterior gaps covering at least 30 per cent of the implant surface promoted cement cracks and destabilized the stem. Anterolateral gaps were less destabilizing, but had more potential to promote cracks. In both cases, cracks occurred mainly outside gap regions, in areas where the stem contacted the cement during cyclic loading. Although random interfacial pores did not destabilize the implant, they acted as crack initiators even at low fractions (10 per cent). In conclusion, random interfacial pores were more harmful for the cement mantle integrity than were larger regions of interfacial gaps, although gaps were more detrimental for the rotational stability of the stem. PMID:19024152

  16. Morphological Study of the Newly Designed Cementless Femoral Stem

    PubMed Central

    Baharuddin, Mohd Yusof; Salleh, Sh-Hussain; Zulkifly, Ahmad Hafiz; Lee, Muhammad Hisyam; Mohd Noor, Alias

    2014-01-01

    A morphology study was essential to the development of the cementless femoral stem because accurate dimensions for both the periosteal and endosteal canal ensure primary fixation stability for the stem, bone interface, and prevent stress shielding at the calcar region. This paper focused on a three-dimensional femoral model for Asian patients that applied preoperative planning and femoral stem design. We measured various femoral parameters such as the femoral head offset, collodiaphyseal angle, bowing angle, anteversion, and medullary canal diameters from the osteotomy level to 150 mm below the osteotomy level to determine the position of the isthmus. Other indices and ratios for the endosteal canal, metaphyseal, and flares were computed and examined. The results showed that Asian femurs are smaller than Western femurs, except in the metaphyseal region. The canal flare index (CFI) was poorly correlated (r < 0.50) to the metaphyseal canal flare index (MCFI), but correlated well (r = 0.66) with the corticomedullary index (CMI). The diversity of the femoral size, particularly in the metaphyseal region, allows for proper femoral stem design for Asian patients, improves osseointegration, and prolongs the life of the implant. PMID:25025068

  17. A stem design change to reduce peak cement strains at the tip of cemented total hip arthroplasty.

    PubMed

    Estok, D M; Harris, W H

    2000-08-01

    A series of 3-dimensional finite element models was created to assess different designs of the tip of the stems of cemented femoral components of total hip arthroplasty that would decrease the peak axial tensile cement strains developed near the tip. Features of stem design that would facilitate positioning the femoral component in a neutral position centered in uniform cement mantle of adequate thickness also were evaluated. These studies showed that a stem that had a narrow tip profile that would accept an externally applied polymethyl methacrylate centralizer shaped similar to a napkin ring and had a gradual transition zone to join the body of the implant achieved these objectives. Such a combination resulted in the reduction of the peak axial strains to less than half the magnitude of the peak strains around a conventional tip (830 vs 1,868 microstrain). The reduction in peak axial strains was to one third the magnitude of the strains developed adjacent to a stem with a hole drilled into the tip to accept the commonly used fin-type polymethyl methacrylate centralizer (830 vs 2,466 microstrain). These goals were achieved because a stem that is designed to accept a napkin ring-style centralizer i) has a lower bending stiffness at the tip of the implant, ii) allows room for a thicker cement mantle, and iii) avoids creating a stress riser adjacent to the edge of the drill hole. The peak cement strains adjacent to a stem of this design are well below the endurance limit of cement as long as the transition zone where the narrow tip meets the body of the implant is gradual. PMID:10959996

  18. Total Hip Arthroplasty Using a Polished Tapered Cemented Stem in Hereditary Multiple Exostosis

    PubMed Central

    Kanda, Akio; Kaneko, Kazuo; Obayashi, Osamu; Mogami, Atsuhiko

    2016-01-01

    A 61-year-old Japanese man underwent right total hip arthroplasty for hereditary multiple exostosis. At first presentation, he had suffered from coxalgia for a long time. On radiographic images, there was a gigantic femoral head, increased shaft angle, and large diameter of the femoral neck. He had also developed coxarthrosis and severe pain of the hip joint. The transformation of the proximal femur bone causes difficulty in setting a cementless total hip prosthesis. Therefore, total hip arthroplasty using a cemented polished tapered stem was performed via a direct lateral approach. Using a cemented polished tapered stem allowed us to deal with the femoral bone transformation and bone substance defectiveness due to exostosis and also minimized the invasiveness of the operation. PMID:27127668

  19. Total Hip Arthroplasty Using a Polished Tapered Cemented Stem in Hereditary Multiple Exostosis.

    PubMed

    Kanda, Akio; Kaneko, Kazuo; Obayashi, Osamu; Mogami, Atsuhiko

    2016-01-01

    A 61-year-old Japanese man underwent right total hip arthroplasty for hereditary multiple exostosis. At first presentation, he had suffered from coxalgia for a long time. On radiographic images, there was a gigantic femoral head, increased shaft angle, and large diameter of the femoral neck. He had also developed coxarthrosis and severe pain of the hip joint. The transformation of the proximal femur bone causes difficulty in setting a cementless total hip prosthesis. Therefore, total hip arthroplasty using a cemented polished tapered stem was performed via a direct lateral approach. Using a cemented polished tapered stem allowed us to deal with the femoral bone transformation and bone substance defectiveness due to exostosis and also minimized the invasiveness of the operation. PMID:27127668

  20. Technical considerations and functional results in primary uncemented hip arthroplasty using short femoral stems through mini-invasive techniques

    PubMed Central

    Moga, M; Pogarasteanu, ME

    2014-01-01

    Abstract Primary hip arthroplasty is a surgical procedure through which the coxofemoral joint is replaced with a prosthetic implant. Arthroplasties can be total or partial, cemented or uncemented. These procedures are generally indicated as a form of treatment for arthritic pain or in the case of severe trauma, such as femoral neck fractures. The most commonly used approaches are: Smith Peterson, Watson Jones, Hardinge, Moore Southern and Ludloff. Recently, mini-invasive approaches have started being used, while correlated with short femoral stems. Short metaphyseal femoral stems have been introduced as an alternative to conventional stems, having a series of advantages: preservation of bone stock (high cervical osteotomies), preservation of the anatomical anteversion of the femural neck, decrease in cortical stress forces, decrease in the remaining thigh pain, a longer life of the prosthesis, with the possibility of revision to a conventional prosthesis, and the possibility to be used in correlation with mini-invasive procedures. Short femoral stems implanted through a mini-invasive approach allow the conservation of the femoral bone stock, permitting an ulterior re-intervention, in the context of an ageing population, with a globally rising long-term survival rate. Moreover, the superiority of the total hip arthroplasty with a short femoral stem was discussed through mini-invasive approaches, in the day-to-day realities of our Clinic. PMID:25408765

  1. Femoral and obturator nerves palsy caused by pelvic cement extrusion after hip arthroplasty.

    PubMed

    Zwolak, Pawel; Eysel, Peer; William-Patrick Michael, Joern

    2011-03-17

    Cement extrusion into the pelvis with subsequent palsy of the obturator and femoral nerves is a rare entity after hip replacement surgery. Cemented fixation of the acetabular cup has been considered as a safe and reliable standard procedure with very good long term results. We present a case of fifty year old female patient after hip arthroplasty procedure which suffered an obturator and femoral nerve palsy caused by extrusion of bone cement into the pelvis. Postoperative X-rays and CT-scan of the pelvis demonstrated a huge mass consisted of bone cement in close proximity of femoral and obturator nerves. The surgery charts reported shallow and weak bony substance in postero-superior aspect of the acetabulum. This weak bony acetabular substance may have caused extrusion of bone cement during press-fitting of the polyethylene cup into the acetabulum, and the following damage of the both nerves produced by polymerization of bone cement. The bone cement fragment has been surgically removed 3 weeks after arthroplasty. The female patient underwent intensive postoperative physical therapy and electro stimulation which resulted in full recovery of the patient to daily routine and almost normal electromyography results. PMID:21808718

  2. Long-term follow-up of a cemented titanium stem.

    PubMed

    Bloch, Benjamin; Brown, Sue; Angadi, Darshan; Crawfurd, Edward

    2015-06-01

    We present the outcome of 270 cemented titanium alloy femoral stems. These patients were followed up annually both clinically and radiologically, and were included up until their last follow-up. 120 patients completed a 10-year follow-up. The 10-year survival of the Ultima Straight Stem cemented femoral component (defined by revision of the femoral stem) was 90.1% (95% CI=84.0-94.0%), with aseptic loosening being the major reason for failure. The preoperative Harris Hip Score improved from 35.3 to 79.3 at 10 years. There were 17 cases of stem subsidence, radiolucent lines in 11 hips, 5 cases of cement fracture and 18 hips had osteolysis in 2 adjacent Gruen zones. This is the largest study in the English literature of this implant, and reflects UK district general hospital practice with surgery performed by a variety of surgical grades and via different surgical approaches. Although the outcome of this implant was within the previous standard set by the National Institute for Health and Clinical Excellence and is comparable to other series of titanium stems, it is inferior to that of more modern cemented and uncemented implants, and falls outside the new NICE recommendation of <5% revision rate at ten year. As a result this implant is no longer used in our institution, and it has also now been withdrawn from the market. We suggest that patients with this implant should be followed up radiologically due to the relatively high rate of stem subsidence and lucency between the cement and prosthesis, to identify those who may be at risk of failure. PMID:26280960

  3. Fracture of Uncemented Revision Femoral Stems in three Arthroplasty Patients: A Case Series with three different brands

    PubMed Central

    Merchant, Rajiv; Kelly, Ian; Quinlan, John

    2014-01-01

    Introduction: Fracture of stems in primary total hip arthroplasty is a known complication and has been attributed to varus positioning, excessive weight of the patient, resorption of the femoral calcar and failure of the cement mantle. Fractures in uncemented revision femoral stems are rare and are attributed to reduction in proximal support either in the form of bone loss or an extended trochanteric osteotomy [ETO] against a distally well- fixed stem. Also, undersized stems and high BMI to increase the risk of stem fracture. Case Report: We report 3 cases of uncemented revision stem fractures. Case 1 is a 77 year old male, Case 2 is a 71- year-old female, case 3 an 82-year-old male. All three patients had significant proximal femoral osteolysis. All three had an extended trochanteric osteotomy for the revision surgery. The hips had remained in-situ for 4, 2 and 5 years respectively prior to fracture. Conclusion: When planning complex revision cases involving long uncemented stems, attention should be given to the above-mentioned variables. ETO non-union and proximal bone loss play an important role in stem fractures. Stem failure can occur irrespective of the make, and factors such as adequate stem size and good diaphyseal fit are non negotiable. PMID:27298992

  4. Augmentation of femoral neck fracture fixation with an injectable calcium-phosphate bone mineral cement.

    PubMed

    Stankewich, C J; Swiontkowski, M F; Tencer, A F; Yetkinler, D N; Poser, R D

    1996-09-01

    The first goal of this study was to determine if augmentation with an injectable, in situ setting, calcium-phosphate cement that is capable of being remodeled and was designed to mimic bone mineral significantly improved the strength and stiffness of fixation in a cadaveric femoral neck fracture model. The second goal was to determine if greater increases in fixation strength were achieved as the bone density of the specimen decreased. Sixteen pairs of fresh cadaveric human femora with a mean age of 70.9 years (SD = 17.2 years) were utilized. The bone density of the femoral neck was measured with dual-energy x-ray absorptiometry. The femoral head was impacted vertically with the femoral shaft fixed in 12 degrees of adduction using a materials testing machine to create a fully displaced fracture. Following fracture, 30% inferior comminution was created in each specimen. One randomly chosen femur from each pair underwent anatomic reduction and fixation with three cannulated cancellous bone screws, 7 mm in diameter, in an inverted triangle configuration. The contralateral femur underwent the same fixation augmented with calcium-phosphate cement. Specimens were preconditioned followed by 1.000 cycles to one body weight (611.6 N) at 0.5 Hz to simulate single-limb stance loading. The stiffness in the first cycle was observed to be significantly greater in cement-augmented specimens compared with unaugmented controls (p < 0.05). After cycling, each specimen was loaded at 10 mm/min until complete displacement of the fracture surface and failure of fixation occurred. Specimens augmented with bone mineral cement failed at a mean of 4,573 N (SD = 1,243 N); this was significantly greater (p < 0.01) than the mean for controls (3,092 N, SD = 1,258 N). The relative improvement in fixation strength (augmented/control x 100%) was not inversely correlated to femoral neck bone density (p = 0.25, R2 = 0.09), was weakly correlated to the volume of cement injected (p = 0.07, R2 = 0

  5. Mechanical Failure of Revision Knee Prosthesis at both Femoral and Tibial Modular Metaphyseal Stem Junctions

    PubMed Central

    Woodgate, Ian G; Rooney, John; Mulford, Johnathan S; Gillies, R Mark

    2016-01-01

    Introduction: This is a report of a mechanical failure of an S-ROM revision total knee prosthesis. The prosthesis was used as a revision implant following deep peri-prosthetic infection in a morbidly obese male. The prosthesis failed on both the femoral and tibial sides at the modular metaphyseal stem junctions and required a further revision using the same type of implant after infection was excluded. Case Presentation: A 57 year old male had previously undergone a left total knee arthroplasty in 1999 for osteoarthritis. He acquired a late deep peri-prosthetic infection with a multi-resistant Staphylococcus epidermidis. The organism was sensitive to vancomycin and rifampicin. A two stage revision was undertaken after clinical signs of infection had resolved and blood parameters had normalized. Intra-operative gram stain was negative for micro-organisms and frozen section of deep tissue was less than five polymorphs per high power field. A cemented S-ROM prosthesis was implanted using a coronal tibial osteotomy and a lateral release for exposure. After three years of the second stage of revision, the patient again presented to the orthopaedic department after reportedly falling on a wet floor six weeks ago. Conclusion: Radiographically, there was a broken tibial wire, osteolysis and pedestal formation around both the femoral and distal tibial stem extensions. The prosthesis was bent at the proximal tibial sleeve and stem junction. The prosthesis was considered loose with mechanical failure. At implant removal, it was noted that the femoral and tibial components at the modular metaphyseal sleeve-stem junction were fractured. Surgeons should be cautious in the use of these implants in morbidly obese patients where the stresses generated maybe above the yield stress of the material and the frictional forces that may overcome the modular taper junction’s locking mechanism. PMID:27299124

  6. Endo medullary extractability of cementless full HA coated femoral stem: Results from 19 cases.

    PubMed

    Lecuire, François; Melere, Gilles; Martres, Sébastien

    2015-03-01

    The Aura cementless full HA coated stem is an anatomical femoral component with a different surface treatment in the metaphyseal and diaphyseal areas. We have studied the feasibility of isolated endo-medullar extraction of the stem. 19 patients (6 infections, 6 neck fractures, 3 stems with risk of fracture, 3 head fractures, and 1 recurrent dislocation) were subjected to the removal of a stable and bone integrated implant at a mean of 4.5 years after surgery. The 19 cases represent the entire population of Aura cementless integrated stem requiring revision during the period of 2003 through 2011, excluding periprosthetic bone fracture cases. The technique consisted of a careful release of the metaphyseal part of the implant with thin osteotomes, followed by the use of a highly efficient extractor. The re-implanted procedure always utilised standard stems: 17 cementless stems full HA coated (13 had the same size as the removed implant, 4 cases had larger sizes) and two received cemented stems. The 19 stems were extracted by simple endo-medullary approach, without the need for additional action. Several complications were encountered, 1 intraoperative diaphyseal fracture, requiring a wiring, 1 fracture of the lesser trochanter at 15 days post-surgery, requiring a revision and 2 postoperative dislocations. Except for the early revision due to fracture, no other stem was revised. There was no recurrence of infection and the functional results were satisfactory (PMA 15-18). 3 patients showed metaphyseal lucent lines on X-Ray leading us to advise the use of a standard stem with larger size after distal reaming, combined with preventive circulate of the calcar. The use of dedicated instrumentation allows successful extraction of full HA coated short stem by endomedullary approach. PMID:26280859

  7. Evaluation of injectable strontium-containing borate bioactive glass cement with enhanced osteogenic capacity in a critical-sized rabbit femoral condyle defect model.

    PubMed

    Zhang, Yadong; Cui, Xu; Zhao, Shichang; Wang, Hui; Rahaman, Mohamed N; Liu, Zhongtang; Huang, Wenhai; Zhang, Changqing

    2015-02-01

    The development of a new generation of injectable bone cements that are bioactive and have enhanced osteogenic capacity for rapid osseointegration is receiving considerable interest. In this study, a novel injectable cement (designated Sr-BBG) composed of strontium-doped borate bioactive glass particles and a chitosan-based bonding phase was prepared and evaluated in vitro and in vivo. The bioactive glass provided the benefits of bioactivity, conversion to hydroxyapatite, and the ability to stimulate osteogenesis, while the chitosan provided a cohesive biocompatible and biodegradable bonding phase. The Sr-BBG cement showed the ability to set in situ (initial setting time = 11.6 ± 1.2 min) and a compressive strength of 19 ± 1 MPa. The Sr-BBG cement enhanced the proliferation and osteogenic differentiation of human bone marrow-derived mesenchymal stem cells in vitro when compared to a similar cement (BBG) composed of chitosan-bonded borate bioactive glass particles without Sr. Microcomputed tomography and histology of critical-sized rabbit femoral condyle defects implanted with the cements showed the osteogenic capacity of the Sr-BBG cement. New bone was observed at different distances from the Sr-BBG implants within eight weeks. The bone-implant contact index was significantly higher for the Sr-BBG implant than it was for the BBG implant. Together, the results indicate that this Sr-BBG cement is a promising implant for healing irregularly shaped bone defects using minimally invasive surgery. PMID:25591177

  8. [Technical principles for removal of femoral bone cements in hip prosthesis implant revision].

    PubMed

    Lauer, W; Neuss, M; Wirtz, D C; Radermacher, K

    2002-01-01

    As the removal of femoral bone cement is one of the most challenging tasks in cemented total Hip Revision, a lot of different technical devices have been developed to aid the surgeon. All of their pros and cons are partly consequences of the specific system-design but mainly arise from the basic physical principles used. The known methods and devices as well as their data-handling have therefore been analysed, reduced to their principles according to the criteria of systematic engineering design and systematized in order to provide a better comparability and starting point for the development of new devices. PMID:12451769

  9. Excessive distal migration of fiber-mesh coated femoral stems

    PubMed Central

    2011-01-01

    Background The surface texture, localization, and magnitude of the surface material applied to the femoral stem can facilitate bone ingrowth and influence the survival of total hip arthroplasties. Clinical and radiographic studies have shown superior bone ingrowth in proximally porous-coated stems with a diaphyseal grit-blasted surface in comparison to a smooth diaphyseal surface. Surface textures—especially porous surface material—have been suggested to have a sealing effect against migration of polyethylene debris along the implant-bone interface and to reduce the inflammatory response, leading to a prolonged implant survival. Patients and methods Between 2004 and 2006, we conducted a randomized, controlled trial (RCT) involving 50 patients with non-inflammatory arthritis. They received either a distally tapered, extended coated stem or a straight, proximally coated stem. During surgery, tantalum markers were inserted into the greater and lesser trochanter. Implant migration was evaluated at 3, 12, and 24 months postoperatively by radiostereometric analysis. The primary endpoint was stem migration 2 years after surgery. Results All femoral components in both groups showed pronounced distal translation, with the highest rate of translation occurring between 0 and 3 months. After 2 years, the mean distal translation was 2.67 (95% CI: –3.93 to –1.42) mm for the tapered, extended coated stem and 1.80 (–2.45 to –1.15) mm for the straight, proximally coated stem. Half of the tapered, extended coated stems and two-thirds of the straight, proximally coated stems had migrated more than 1 mm. No difference between the 2 stems could be seen with regard to translation or rotation at any time point. After 2 years, 2 hips have been reoperated due to mechanical loosening of the stem. Interpretation An excessive amount of migration of both stem types was seen 2 years postoperatively. It is of vital importance to follow this patient cohort since radiostereometric

  10. Importance of a distal centralizer in experimental malpositioning of cemented stems. A biomechanical study on human femora

    PubMed Central

    Ficklscherer, Andreas; Kreuz, Peter Cornelius; Finze, Susanne; Mittelmeier, Wolfram; Jansson, Volkmar; Milz, Stefan; Wegener, Bernd

    2015-01-01

    Introduction Femoral centralizers in total hip arthroplasty (THA) are designed to improve the neutral implant position and ensure a homogeneous cement mantle without implant-bone impingement. To date there are no data about the cement mantle configuration and implant position after malinsertion, as seen in mini-open approaches or adipose patients with a limited view. The present biomechanical study was performed to investigate whether a distal centralizer may correct and optimize the position of a malinserted femoral stem. Material and methods Thirteen MS 30 stems with and without a distal centralizer each were implanted in paired fresh human femora. Malinsertion was performed using a 3D guiding device with 10° deviation to the femoral axis in the sagittal plane. The thickness of the cement mantle was measured on the anterior, posterior, medial and lateral side of the implanted stem at a distance of 1 cm each. For each side data were taken at 13 points. Results Digital evaluation of the cement mantle thickness revealed compareable values in frontal plane when a centralizer was used (p > 0.4). In contrast the cement mantle thicknesses without a centralizing device varied in the distal region between 3.38 mm and 5.09 mm (p ≤ 0.001) and in the central region between 3.52 mm and 4.19 mm (p ≤ 0.009). Conclusions A distal centralizer allows a more uniform cement mantle and neutral alignment even with a malinsertion of the femoral stem. This could reduce the failure rate and early loosening in complex THA. PMID:26788098

  11. The treatment of metastasis to the femoral neck using percutaneous hollow perforated screws with cement augmentation.

    PubMed

    Kang, H G; Roh, Y W; Kim, H S

    2009-08-01

    We have developed a hollow perforated cannulated screw. One or more of these was implanted percutaneously in 11 patients with an osteolytic metastasis in the femoral neck and multiple metastases elsewhere. They were supplemented by one or two additional standard 6.5 mm cannulated screws in nine patients. Polymethylmethacrylate bone cement was injected through the screw into the neck of the femur using small syringes, as in vertebroplasty. The mean amount of cement injected was 23.2 ml (17 to 30). Radiotherapy was started on the fourth post-operative day and chemotherapy, on average, was resumed a day later. Good structural stability and satisfactory relief from pain were achieved in all the patients. This technique may be useful in the palliation of metastases in the femoral neck. PMID:19651838

  12. Cemented hemiarthroplasty in traumatic displaced femoral neck fractures and deep vein thrombosis: is there really a link?

    PubMed Central

    Hong, Choon Chiet; Nashi, Nazrul; Makandura, Milindu Chanaka; Krishna, Lingaraj

    2016-01-01

    INTRODUCTION Traumatic displaced femoral neck fractures in the elderly can be treated with cemented or uncemented hemiarthroplasty with good outcomes. Earlier studies reported a higher incidence of deep vein thrombosis (DVT) associated with cemented prostheses in elective total hip or knee arthroplasty. In addition, the hypercoagulable state after a traumatic femoral neck fracture and possible thrombogenic properties of bone cement could put these patients at greater risk for thromboembolism. We aimed to compare the incidence of DVT and progression to pulmonary embolism (PE) or mortality in cemented and uncemented hemiarthroplasty. METHODS The data of 271 patients treated with cemented or uncemented hemiarthroplasty after a traumatic displaced femoral neck fracture was retrospectively analysed for the incidence of DVT. The level of thrombosis, progression to PE and mortality were compared. RESULTS There were 133 (49.1%) patients with cemented hemiarthroplasty, while 138 (50.9%) had uncemented hemiarthroplasty. The patients had an average age of 76.6 (range 53–99) years and 11 (4.1%) patients had DVT. There were no significant differences in development of DVT, level of thrombosis, PE and mortality regardless of whether a cemented or an uncemented prosthesis was used. CONCLUSION Cemented hemiarthroplasty is not associated with higher risks of DVT, PE or mortality in patients with traumatic displaced femoral neck fracture. Cemented prostheses can be safely used for this group of patients. PMID:26892829

  13. A preclinical study of stem subsidence and graft incorporation after femoral impaction grafting using porous hydroxyapatite as a bone graft extender.

    PubMed

    Howie, Donald W; McGee, Margaret A; Callary, Stuart A; Carbone, Angelo; Stamenkov, Roumen B; Bruce, Warrick J; Findlay, David M

    2011-10-01

    This preclinical in vivo screening study compared bone graft incorporation and stem subsidence in cemented hemiarthroplasty after femoral impaction bone grafting with either morselized allograft bone (n = 5, control group) or a 1:1 mix of allograft and porous hydroxyapatite ceramics (HA) granules (n = 5, HA group). At 14 weeks, there was excellent bone graft incorporation by bone, and the stems were well fixed in both groups. The median subsidence at the cement-bone interface, measured using radiostereometric analysis, was 0.14 and 0.93 mm in the control and HA groups, respectively. The comparable histologic results between groups and good stem fixation in this study support the conduct of a larger scale investigation of the use of porous HA in femoral impaction bone grafting at revision hip arthroplasty. PMID:21802252

  14. Periprosthetic Insufficiency Fracture around Radiographically Loose Cemented Stem: A Report of Two Cases

    PubMed Central

    Chun, Young Soo; Lee, Jung Suk; Cho, Yoon Je

    2015-01-01

    As the osteoporotic patient population grows, various periprosthetic fractures that cannot be classified appropriately can occur around the femur after hip arthroplasty. We experienced two cases of periprosthetic insufficiency fractures at subtrochanteric area of the femurs around radiographically loose cemented femoral stems. The ages of the patients were 75 years and 83 years. Both patients could not recall any history of trauma before the onset of pain. Both were treated non-operatively. Both healed uneventfully and did not recur after two years of follow up. When the osteoporotic patient with cemented stem showed sudden hip or thigh pain without a history of trauma, great attention should be focused to find this lesion. PMID:27536623

  15. A simple new technique for the removal of fractured femoral stems: a case report

    PubMed Central

    2014-01-01

    Introduction The removal of broken femoral stems has become a major issue in revision surgery, and is a technically difficult and time-consuming procedure. Case presentation We present a case of a fracture of a cementless long femoral stem in a 65-year-old, white Caucasian man. The distal part was removed with a special longitudinal osteotomy through the anterior cortex extending distally for 10cm. It was then followed by a transversal osteotomy 2cm below the tip of the femoral stump to allow enough space for two locking pliers. Simultaneously using a lamina spreader on the distal part, the broken stem was extracted while hammering on two locking pliers. Conclusions We developed a simple and easy technique for the removal of a broken femoral stem that can be applied to all kinds of femoral stems and intramedullary nails regardless of their cross section. We used ordinary surgical instruments and spared the remaining bone stock. PMID:24886067

  16. Transesophageal echocardiography and clinical features of fat embolism during cemented total hip arthroplasty. A randomized study in patients with a femoral neck fracture.

    PubMed

    Pitto, R P; Blunk, J; Kössler, M

    2000-01-01

    Forty patients suffering from a medial femoral neck fracture participated in a prospective, randomized study. In 20 patients, the femoral component was cemented using a contemporary technique. In the patient group operated on with the bone vacuum technique, the medullary cavity was drained during the insertion of the stem. The proximal draining hole was placed in the intertrochanteric region, along the prolongation of the linea aspera. The distal hole was placed 2 cm below the tip of the femoral component. Embolic phenomena were documented intraoperatively by continuous transesophageal echocardiographic imaging of the right atrium and ventricle. The clinical relevance of the emboli was noted simultaneously by recording hemodynamic and blood gas parameters. Patients of the control group showed severer and longer-lasting episodes of embolism than patients of the bone vacuum group. Ongoing emboli were first seen during the injection of the cement, and continued during stem insertion. Massive emboli of small particles could be verified in 19 patients (95%) of the control group and in 1 patient (5%) of the bone vacuum group (P < 0.05). During massive emboli, a distinct decrease in the arterial oxygen saturation and the end-expiratory carbon dioxide level was observed. The calculated average pulmonary shunt volume showed an increase after the insertion of the stem using the contemporary technique (36.5%; P < 0.05). These distinct hemodynamic changes were not observed in the bone vacuum group. This study was able to show a clearly reduced risk of pulmonary emboli using the bone vacuum cementing technique. The presence of pre-existing disease greatly magnified the clinical relevance of fat embolism. PMID:10653105

  17. Aseptic stem loosening in primary THA: migration analysis of cemented and cementless fixation

    PubMed Central

    Kroell, Artur; Beaulé, Paul; Krismer, Martin; Behensky, Hannes; Stoeckl, Bernd

    2008-01-01

    Early migration has reportedly been predictive for later implant failure. Using four different migration patterns, this study aimed to analyse migration behaviour of the two types of implant fixation—cemented and cementless—throughout the process of loosening. Migrational behaviour of 69 revised stems (49 cemented, 20 uncemented) was analysed retrospectively with EBRA-FCA (Einzel-Bild-Röntgen-Analyse, Femoral Component Analysis). Uncemented stems failed after early and late onset migration alike, while late migration was the predominant pattern in cemented stems. Mean prosthetic failure after early migration occurred 5.8 (±4.4) years postoperatively due to insufficient primary stability. Initially stable stems with late onset migration were revised after 12.4 (±4.5) years. Measurement of early migration was found to be a valuable tool to screen short-term and mid-term failure. In the long run the method’s sensitivity decreased. Late onset migration, however, preceded long-term failure by a mean of three years. PMID:19066889

  18. Adhesive strength of total knee endoprostheses to bone cement - analysis of metallic and ceramic femoral components under worst-case conditions.

    PubMed

    Bergschmidt, Philipp; Dammer, Rebecca; Zietz, Carmen; Finze, Susanne; Mittelmeier, Wolfram; Bader, Rainer

    2016-06-01

    Evaluation of the adhesive strength of femoral components to the bone cement is a relevant parameter for predicting implant safety. In the present experimental study, three types of cemented femoral components (metallic, ceramic and silica/silane-layered ceramic) of the bicondylar Multigen Plus knee system, implanted on composite femora were analysed. A pull-off test with the femoral components was performed after different load and several cementing conditions (four groups and n=3 components of each metallic, ceramic and silica/silane-layered ceramic in each group). Pull-off forces were comparable for the metallic and the silica/silane-layered ceramic femoral components (mean 4769 N and 4298 N) under standard test condition, whereas uncoated ceramic femoral components showed reduced pull-off forces (mean 2322 N). Loading under worst-case conditions led to decreased adhesive strength by loosening of the interface implant and bone cement using uncoated metallic and ceramic femoral components, respectively. Silica/silane-coated ceramic components were stably fixed even under worst-case conditions. Loading under high flexion angles can induce interfacial tensile stress, which could promote early implant loosening. In conclusion, a silica/silane-coating layer on the femoral component increased their adhesive strength to bone cement. Thicker cement mantles (>2 mm) reduce adhesive strength of the femoral component and can increase the risk of cement break-off. PMID:25781660

  19. Fracture of the femoral alignment stem of a hip resurfacing arthroplasty. A case report.

    PubMed

    Bhutta, Mohammed A; Shah, Vinod B

    2011-02-01

    Metal-on-metal hip resurfacing arthroplasty has become increasingly popular for the treatment of osteoarthritis in a younger patient population. While the initial complication of femoral neck fracture is being addressed, we describe a fracture of the femoral alignment stem in a component two years from the primary procedure. PMID:21473460

  20. [Finite element analysis of a cemented ceramic femoral component for the assembly situation in total knee arthroplasty].

    PubMed

    Schultze, Christine; Klüss, Daniel; Martin, Heiner; Hingst, Volker; Mittelmeier, Wolfram; Schmitz, Klaus-Peter; Bader, Rainer

    2007-08-01

    The femoral components of the total knee replacements are generally made of metal. In contrast, ceramic femoral components promise improved tribological and allergological properties. However, ceramic components present a risk of failure as a result of stress peaks. Stress peaks can be minimised through adequate implant design, proper material composition and optimum force transmission between bone and implant. Thus, the quality of the implant fixation is a crucial factor. The objective of the present study was to analyse the influence of the cement layer thickness on stress states in the ceramic femoral component and in the femur. Two- and three- dimensional finite element analyses of an artificial knee joint with cement layers of different thickness and with an unbalanced cement layer thickness between the ceramic femoral component and the femur were performed. Higher stress regions occurred in the area of force transmission and in the median plane. The maximum calculated stresses were below the accepted tensile strength. Stresses were found to be lower for cement layer thickness of <2.0 mm. PMID:17691864

  1. Use of an anatomic long-stemmed component in femoral impaction grafting.

    PubMed

    Westerman, Richard W; Timperley, Andrew J

    2016-01-01

    We describe a challenging femoral revision for aseptic loosening in a relatively young and active man. The femur had gross osteolysis, an absent calcar and a cortical diaphyseal defect at the level of the isthmus (Paprosky 3b defect). The cortical defects were repaired and the whole femur then restored with Femoral Impaction Grafting (FIG) using custom-made impaction instruments and an anatomic shaped collarless, polished, tapered femoral component.In the active adult, bone restoring revision techniques such as impaction grafting should be considered to give a realistic prospect of host bone augmentation rather than simply aiming for a distally fixed stem in a patulous femoral canal. PMID:26692247

  2. Mid-term Results of Revision Total Hip Arthroplasty Using Modular Cementless Femoral Stems

    PubMed Central

    Jang, Hyung-Gyu; Min, Byung-Woo; Ye, Hee-Uk; Lim, Kyung-Hwan

    2015-01-01

    Purpose The purpose of this study was to evaluate the clinical and radiological results of revision total hip arthroplasty using modular distal fixation stems for proximal femoral deficiency. Materials and Methods Forty-five patients (47 hips) were analyzed more than 24 months after revision total hip arthroplasty that used modular distal fixation stems and was performed between 2006 and 2012. There were proximal femoral defects in all cases. Preoperative femoral defect classification revealed Paprosky type II in 31 cases, type IIIA in 7, and type IIIB in 9. The mean duration of follow-up was 53.4 (25-100) months. We evaluated the Harris hip score (HHS), walking ability according to Koval as clinical parameters, stem stability, and stem position change as radiographic parameters. Kaplan-Meier survival analysis was performed. Results The average HHS improved form 39.5 points to 91.3 points and walking ability also improved in most cases; all patients had stable fixation of the femoral stem. Postoperative complications included 5 cases of infection and 2 cases of dislocation. The survival rate with the end point of re-revision surgery due to infection or dislocation was 86% after 8-year follow-up. Conclusion Cementless revision total hip arthroplasty using modular femoral stems is useful because the stems can be stably fixed on the diaphyseal portion of the femur, which has relatively good bone quality at mid-term follow-up. PMID:27536616

  3. The effects of cement-stem debonding in THA on the long-term failure probability of cement.

    PubMed

    Verdonschot, N; Huiskes, R

    1997-08-01

    The damage accumulation failure scenario is one of the most prominent ones of cemented THA reconstruction, and involves the accumulation of mechanical damage in materials and interfaces due to repetitive dynamic loading eventually resulting in gross loosening. This study addresses this scenario by combining finite element techniques with the theory of continuum damage mechanics, to analyze the damage accumulation process in the cement mantle. It was investigated how damage accumulation was affected by stem-cement debonding, and what the effects of a layer with poor bone quality around the cement mantle were. For the unbonded stem, it was determined if clinical migration rates can be explained by failure of the cement mantle, and whether cement failure promotes the formation of a pathway for debris at the stem-cement interface. It was found that stem-cement debonding not only elevated the initial stress levels with a factor of about two to three as demonstrated in earlier studies, but remained to have an impact on the failure process of the cement mantle. Stem-cement debonding accelerated the failure process by a factor of four, and promoted the formation of a pathway for debris at the stem-cement interface, particularly when the bone support to the cement mantle was reduced. The amount of subsidence was only substantial when the damaged cement mantle was surrounded by a layer of bone with reduced stiffness. This study supports the hypothesis that the survival of cemented THA is enhanced by a firm and lasting bond between the stem and the cement mantle, although this may be difficult to realize clinically. PMID:9239564

  4. New Approach and Stem Increased Femoral Revision Rate in Total Hip Arthroplasty.

    PubMed

    Panichkul, Phonthakorn; Parks, Nancy L; Ho, Henry; Hopper, Robert H; Hamilton, William G

    2016-01-01

    This study compared the femoral stem revision and loosening rates in primary total hip arthroplasty between 2 different approaches and stem designs. Recent reports comparing the direct anterior approach with either the posterior or lateral approach showed that patients undergoing the direct anterior approach have less pain and an accelerated functional recovery in the early postoperative period. After converting to an anterior approach, the authors observed an increased rate of femoral stem revision. From 2003 to 2009, a posterior or lateral approach was used to insert 514 stems of 2 designs. These cases included the use of an extensively coated cobalt-chrome stem (n=232) or a straight, dual-tapered, proximally porous-coated titanium stem (n=282). In the following years, from 2009 to 2012, 594 short, proximally coated, titanium tapered-wedge stems were inserted through a direct anterior approach. The revision rates of femoral stems inserted through a posterior approach or a lateral approach were compared with those inserted via a direct anterior approach. No stem revisions occurred in the posterior approach group or the lateral approach group, and 5 stems were revised in the anterior approach group for periprosthetic fracture or aseptic loosening (0.8%). Significantly more stem revisions occurred after the use of the new stem design and a direct anterior approach (P=.04). PMID:26726989

  5. Sensitivity analysis of a cemented hip stem to implant position and cement mantle thickness.

    PubMed

    Shi, J; Browne, M; Strickland, M; Flivik, G; Taylor, M

    2014-11-01

    Patient-specific finite element models of the implanted proximal femur can be built from pre-operative computed tomography scans and post-operative X-rays. However, estimating three-dimensional positioning from two-dimensional radiographs introduces uncertainty in the implant position. Further, accurately measuring the thin cement mantle and the degree of cement-bone interdigitation from imaging data is challenging. To quantify the effect of these uncertainties in stem position and cement thickness, a sensitivity study was performed. A design-of-experiment study was implemented, simulating both gait and stair ascent. Cement mantle stresses and bone-implant interface strains were monitored. The results show that small variations in alignment affect the implant biomechanics, especially around the most proximal and most distal ends of the stem. The results suggest that implant position is more influential than cement thickness. Rotation around the medial-lateral axis is the dominant factor in the proximal zones and stem translations are the dominant factors around the distal tip. PMID:23405986

  6. Substantially higher prevalence of postoperative peri-prosthetic fractures in octogenarians with hip fractures operated with a cemented, polished tapered stem rather than an anatomic stem.

    PubMed

    Mukka, Sebastian; Mellner, Carl; Knutsson, Björn; Sayed-Noor, Arkan; Sköldenberg, Olof

    2016-06-01

    Background and purpose - Recent studies have demonstrated a high incidence of postoperative periprosthetic femoral fracture (PPF) in elderly patients treated with 2 commonly used cemented, polished tapered stems. We compared the prevalence and incidence rate of PPF in a consecutive cohort of octagenerians with femoral neck fractures (FNFs) treated with either a collarless, polished tapered (CPT) stem or an anatomic matte stem (Lubinus SP2). Patients and methods - In a multicenter, prospective cohort study, we included 979 hips in patients aged 80 years and above (72% females, median age 86 (80-102) years) with a femoral neck fracture as indication for surgery. 69% of the patients were classified as ASA class 3 or 4. Hip-related complications and repeat surgery were assessed at a median follow-up of 20 (0-24) months postoperatively. Results - 22 hips (2.2%) sustained a PPF at a median of 7 (0-22) months postoperatively; 14 (64%) were Vancouver B2 fractures. 7 of the 22 surgically treated fractures required revision surgery, mainly due to deep infection. The cumulative incidence of PPFs was 3.8% in the CPT group, as compared with 0.2% in the SP2 group (p < 0.001). The risk ratio (RR) was 16 (95% CI: 2-120) using the SP2 group as denominator. Interpretation - The CPT stem was associated with a higher risk of PPF than the SP2 stem. We suggest that the tapered CPT stem should not be used for the treatment of femoral neck fractures in patients over 80 years. PMID:27045318

  7. Substantially higher prevalence of postoperative peri­prosthetic fractures in octogenarians with hip fractures operated with a cemented, polished tapered stem rather than an anatomic stem

    PubMed Central

    Mukka, Sebastian; Mellner, Carl; Knutsson, Björn; Sayed-Noor, Arkan; Sköldenberg, Olof

    2016-01-01

    Background and purpose Recent studies have demonstrated a high incidence of postoperative periprosthetic femoral fracture (PPF) in elderly patients treated with 2 commonly used cemented, polished tapered stems. We compared the prevalence and incidence rate of PPF in a consecutive cohort of octagenerians with femoral neck fractures (FNFs) treated with either a collarless, polished tapered (CPT) stem or an anatomic matte stem (Lubinus SP2). Patients and methods In a multicenter, prospective cohort study, we included 979 hips in patients aged 80 years and above (72% females, median age 86 (80–102) years) with a femoral neck fracture as indication for surgery. 69% of the patients were classified as ASA class 3 or 4. Hip-related complications and repeat surgery were assessed at a median follow-up of 20 (0–24) months postoperatively. Results 22 hips (2.2%) sustained a PPF at a median of 7 (0–22) months postoperatively; 14 (64%) were Vancouver B2 fractures. 7 of the 22 surgically treated fractures required revision surgery, mainly due to deep infection. The cumulative incidence of PPFs was 3.8% in the CPT group, as compared with 0.2% in the SP2 group (p < 0.001). The risk ratio (RR) was 16 (95% CI: 2–120) using the SP2 group as denominator. Interpretation The CPT stem was associated with a higher risk of PPF than the SP2 stem. We suggest that the tapered CPT stem should not be used for the treatment of femoral neck fractures in patients over 80 years. PMID:27045318

  8. Custom stems for femoral deformity in patients less than 40 years of age

    PubMed Central

    Akbar, Michael; Aldinger, Guenther; Krahmer, Knut; Bruckner, Thomas

    2009-01-01

    Background and purpose Femoral deformity associated with osteoarthritis is a challenge for both the surgeon and the implant. Many of the patients with these deformities are young. Standard implants can be difficult to fit into these femurs. We prospectively evaluated the outcome of custom uncemented femoral stems in young patients. Methods 61 consecutive patients (72 hips) underwent surgery for osteoarthritis because of femoral deformity at a mean age of 35 (22–40) years. The patients received a CT3D-A custom-made femoral stem and an uncemented cup. The mean follow-up time was 14 (10–16) years. 2 patients died at 7 and 8 years after surgery, otherwise, none of the patients were lost to follow-up. Results At follow-up, the femoral prosthesis had not been revised in 59 patients (70 hips). 3 patients (3 hips) had required revision surgery due to loosening of the acetabular component; 2 hips were awaiting revision surgery for loosening of the acetabular cup. There were no cases of dislocation or infection. At review, all stems were considered stable according to the radiographic criteria. No migration or subsidence was observed on plain radiographs. Interpretation Our results are comparable to published results of custom stems regarding survival and outcome. Considering the young age and the deformities in this series of uncemented custom femoral stems, and the fact that there was follow-up of up to 16 years, the survival is remarkable. This technique appears to be a reasonable alternative in younger patients with femoral deformities. PMID:19513891

  9. The use of hydroxyapatite on press-fit tapered femoral stems.

    PubMed

    Maheshwari, Aditya V; Ranawat, Amar S; Ranawat, Chitranjan S

    2008-09-01

    The advantage of an HA coating includes superior proximal femoral osteointegration and reduced thigh pain, reduced subsidence risk, reduced distal wear particle migration, and better preservation of periprosthetic bone quality. Furthermore, the survivorship and clinical outcomes are at least comparable to cemented and uncoated uncemented systems without any substantial deleterious effect of the HA coating like third-body wear or late failures. In our opinion, these advantages justify the increased cost. With over 20 years of favorable cumulative data, the continued use of HA can be recommended as an effective and reliable adjunct to cementless tapered femoral fixation in primary THA. PMID:18814599

  10. Mechanical effects of stem cement interface characteristics in total hip replacement.

    PubMed

    Verdonschot, N; Huiskes, R

    1996-08-01

    Stem cement debonding is 1 of the most common forms of fixation failure and is thought to be a prelude to gross loosening of a total hip reconstruction. However, the immediate consequences of debonding remains a matter of controversy. The dynamic effects of stem cement debonding in total hip reconstruction were analyzed using 3-dimensional finite element techniques. Stem cement interface conditions were assumed as completely bonded or unbonded, with or without friction. The dynamic effects were accounted for, as presented by the stance and swing phases of the gait cycle. It was found that both cyclic micromotions at the stem cement interface and stresses in the cement mantle were effectively reduced by friction. The friction cases produced failure probabilities of the cement mantle that were relatively close to the one generated by the bonded stem. The probability of mechanical failure of the cement bone interface decreased after debonding and decreased more with reduced stem cement friction. These results show that, although a firm and lasting bond between stem and cement may be desirable for preventing cement failure, the mechanical effects of a debonded stem are less detrimental than were assumed earlier. For straight tapered stem shapes subjected to the loading conditions described, a polished stem may be desirable for the cement bone interface mechanics. PMID:8769468

  11. Fixation of non-cemented total hip arthroplasty femoral components in a simulated proximal bone defect model.

    PubMed

    Sangiorgio, Sophia N; Ebramzadeh, Edward; Knutsen, Ashleen R; Borkowski, Sean L; Kalma, Jeremy J; Bengs, Benjamin C

    2013-10-01

    An accelerated sequential proximal femoral bone loss model was used to measure the initial stability of three noncemented femoral stem designs: fully porous-coated, proximally porous-coated, and dual-tapered, diaphyseal press-fit (N=18). Only dual-tapered, diaphyseal press-fit stems remained stable with as much as 105 mm of bone loss, with average cyclic micromotion remaining below 25 μm in ML and below 10 μm in AP planes. In contrast, with proximally coated and fully coated stem designs with circular or oval cross-sections, 60mm of bone loss, resulting in lower than 10 cm of diaphyseal bone contact length, led to gross instability, increasing average cyclic micromotions to greater than 100 μm prior to failure. Therefore, the results provide support for using a dual-tapered stem in revision cases with proximal bone loss. PMID:23523487

  12. Contact damage failure analyses of fretting wear behavior of the metal stem titanium alloy-bone cement interface.

    PubMed

    Zhang, Lanfeng; Ge, Shirong; Liu, Hongtao; Wang, Qingliang; Wang, Liping; Xian, Cory J

    2015-11-01

    Although cemented titanium alloy is not favored currently in the Western world for its poor clinical and radiography outcomes, its lower modulus of elasticity and good biocompatibility are instrumental for its ability supporting and transforming physical load, and it is more suitable for usage in Chinese and Japanese populations due to their lower body weights and unique femoral characteristics. Through various friction tests of different cycles, loads and conditions and by examining fretting hysteresis loops, fatigue process curves and wear surfaces, the current study investigated fretting wear characteristics and wear mechanism of titanium alloy stem-bone cement interface. It was found that the combination of loads and displacement affected the wear quantity. Friction coefficient, which was in an inverse relationship to load under the same amplitude, was proportional to amplitudes under the same load. Additionally, calf serum was found to both lubricate and erode the wear interface. Moreover, cement fatigue contact areas appeared black/oxidative in dry and gruel in 25% calf serum. Fatigue scratches were detected within contact areas, and wear scars were found on cement and titanium surfaces, which were concave-shaped and ring concave/ convex-shaped, respectively. The coupling of thermoplastic effect and minimal torque damage has been proposed to be the major reason of contact damage. These data will be important for further studies analyzing metal-cement interface failure performance and solving interface friction and wear debris production issues. PMID:26241891

  13. Impact of stem-broach sizing on the cement mantle of Lubinus SP II stems. A CT scan analysis.

    PubMed

    Scheerlinck, Thierry; de Mey, Johan; Deklerck, Rudi

    2009-06-01

    Lubinus SP II stems are cemented either line-to-line with the largest broach or one-size undersized. The purpose of this study was to compare both implantation techniques. We used 18 polymeric stem replicas cemented line-to-line and undersized in paired cadaveric femora and analyzed them with CT scan images. Cementing Lubinus stems line-to-line resulted in higher medullary canal-filling indices (28.26 +/- 4.10%), thinner cement mantles (3.29 +/- 0.40 mm), more cement defects (5.12 +/- 1.69%) and more areas of thin cement (23.81 +/- 7.13%) than undersizing (respectively: 23.61 +/- 4.24%, 3.62 +/- 0.43 mm, 1.48 +/- 2.04%, 15.11 +/- 5.93%). In both settings, over 80% of areas of thin or deficient cement were supported by cortex. Using a line-to-line technique, adequate stem alignment was achieved without distal centralizer. Undersizing the stem and using a distal centralizer reduced the incidence of distal cement defects by a factor 10. While stems cemented line-to-line might have mechanical advantages, undersizing and using distal centralizers reduced potential pathways for debris migration to the bone-cement interface. PMID:19681321

  14. Radiostereometric migration analysis of the Cerafit femoral stem: 28 patients followed for 2 years.

    PubMed

    Tschunko, Franz; Wagner, Benedikt; Hong, Yutong; Söder, Stephan; Wölfel, Rainer; Müller, Lutz A; Forst, Raimund; Sesselmann, Stefan

    2016-06-01

    Radiostereometric analysis (RSA) is the gold standard evaluating micromovements after total hip arthroplasty. The aim of this study was to investigate the migratory pattern of an uncemented femoral stem during the first 2 years after surgery. We followed 28 patients with a mean age of 57 (SD 13) years for the first two postoperative years. Radiostereometric analysis was used to measure the translation and rotation of the femoral component. The Harris hip score (HHS) was determined to evaluate the clinical outcome. No stem had to be revised. The mean HHS advanced from 35 (SD 11) preoperative to 89 (SD 10) 1 year after surgery. At the end of the observation period, mean subsidence of the stem was 0.26 mm (SD 0.82). Maximum total point motion (MTPM) was 1.23 mm (SD 1.22). The main distal migration took place up to 6 weeks after surgery with nearly no further subsidence up to 2 years postoperatively. All the measured migrations of the hip stem were very small. Results of the HHS demonstrate good clinical outcome. Long-term RSA is necessary to assess possible late migration of the Cerafit standard femoral stem. PMID:25996482

  15. Design process of cementless femoral stem using a nonlinear three dimensional finite element analysis

    PubMed Central

    2014-01-01

    Background Minimal available information concerning hip morphology is the motivation for several researchers to study the difference between Asian and Western populations. Current use of a universal hip stem of variable size is not the best option for all femur types. This present study proposed a new design process of the cementless femoral stem using a three dimensional model which provided more information and accurate analysis compared to conventional methods. Methods This complete design cycle began with morphological analysis, followed by femoral stem design, fit and fill analysis, and nonlinear finite element analysis (FEA). Various femur parameters for periosteal and endosteal canal diameters are measured from the osteotomy level to 150 mm below to determine the isthmus position. Results The results showed better total fit (53.7%) and fill (76.7%) canal, with more load distributed proximally to prevent stress shielding at calcar region. The stem demonstrated lower displacement and micromotion (less than 40 μm) promoting osseointegration between the stem–bone and providing primary fixation stability. Conclusion This new design process could be used as a preclinical assessment tool and will shorten the design cycle by identifying the major steps which must be taken while designing the femoral stem. PMID:24484753

  16. Effects of mechanical testing device variables on polymer composite femoral stem strains.

    PubMed

    Heiner, A D; Brown, S A; Davy, D T

    1996-12-01

    Polymer composite femoral stems do not have a well-established in vitro mechanical testing method. The objective of this study was to examine mechanical testing devices for pressfit composite stems, using finite element analysis. The goals were to examine the effects of testing device design variables (geometry, material, interface friction, embedding height and applied load angle) and to reproduce the maximum strains of the stem implanted in a femur. The stem strains were affected by design changes to the testing device. The maximum normal and interlaminar shear strains of the composite stem in the femur were not as well reproduced by the testing device as were the maximum in-plane tensile strains. Decreasing the embedding height increased the stem strains and shifted the stem failure location from the neck to the embedding height. Testing a femoral stem using a testing device with a low embedding height may be inappropriate when trying to induce neck failure, since failure may occur at the embedding height instead of in the neck. A single-material testing device of birchwood, an orthotropic material with a longitudinal stiffness in the range of bone; best simulated a femur in this study. PMID:8968514

  17. Heterologous mesenchymal stem cells successfully treat femoral pseudarthrosis in rats

    PubMed Central

    2012-01-01

    Background This study evaluated the effectiveness of treating pseudarthrosis in rats by using bone marrow cell suspensions or cultures of bone marrow mesenchymal stromal cells Methods Thirty-eight specific pathogen-free (SPF) animals were randomly assigned to four groups: Group 1, Control, without surgical intervention; Group 2 (Placebo), experimental model of femoral pseudarthrosis treated only with saline solution; Group 3, experimental model of femoral pseudarthrosis treated with heterologous bone marrow cells suspension; Group 4, experimental model of femoral pseudarthrosis treated with cultures of heterologous mesenchymal stromal cells from bone marrow. When pseudarthrosis was confirmed by simple radiological studies, digital radiography and histopathology after a 120-day postoperative period, Groups 2, 3 and 4 were treated as above. At 30, 60 and 90 days after the treatment, all animals were evaluated by simple radiological studies, and at the end of the experiment, the animals were assessed by computed axial tomography and anatomopathological and histomorphometric examinations. Results Injected cells were detected in the areas affected by pseudarthrosis using scintigraphy within the first 24 hours after their administration. After 60 days, the animals of Group 3 showed callus formation while the animals of Group 4 presented periosteal reaction and had some consolidated areas. In contrast, Group 2 showed a predominance of fibro-osteoid tissue. After 90 days, bone consolidation and remodeling was observed in all animals from Group 3 whereas animals from Group 4 exhibited partial consolidation and those ones from Group 2 persisted with pseudarthrosis. Conclusion The treatment with heterologous bone marrow cells suspension proved to be effective in the treatment of pseudarthrosis whereas cultures of heterologous bone marrow mesenchymal stromal cells did not show the same potential to aid bone healing. PMID:22429995

  18. The Short-term Clinical Outcome of Total Hip Arthroplasty Using Short Metaphyseal Loading Femoral Stem

    PubMed Central

    Choi, Yoo Wang

    2016-01-01

    Purpose The purpose of this study was to retrospectively evaluate the short-term clinical and radiological outcomes of total hip arthroplasty (THA) with short metaphyseal loading femoral stem. Materials and Methods We retrospectively reviewed the records of 56 cases in 47 patients who had undergone THA with short metaphyseal loading femoral stem from April 2010 to December 2011. There were 20 males and 27 females. The mean age was 54 years (range, 26-77 years). The average follow up period was 4.6 years. Clinical results were evaluated by Harris hip scores (HHS) before the operation and at the last follow-up. Radiographic analysis was done by evaluating osteolysis, loosening, stress shielding, and alignement. Results The mean HHS significantly improved from 45 (range, 15-58) preoperatively to 98 (range, 85-100) at the last follow-up. In radiographic analyses, there was no evidence of osteolysis or loosening around the stems and the acetabuluar components. All cases showed rounding off of the calcar, grade 1 bone resorption of the proximal femur. With regard to implant alignment, 51 femoral component (91.1%) were in neutral position, and 5 (8.9%) were in varus position. There was 1 intraoperative fracture treated by cerclage wiring and no case was revised during follow-up period. Conclusion Although longer follow-up is needed to confirm the durability of the short metaphyseal loading femoral stem, this short stem might provide stable fixation without diaphyseal fixation and demonstrated good clinical result at mean 4.6 year short term follow-up. PMID:27536649

  19. Early migration characteristics of a hydroxyapatite-coated femoral stem: an RSA study.

    PubMed

    Campbell, David; Mercer, Graham; Nilsson, Kjell G; Wells, Vanessa; Field, John R; Callary, Stuart A

    2011-04-01

    Measurement of early stem subsidence can be used to predict the likelihood of long-term femoral component loosening and clinical failure. Data that examines the early migration pattern of clinically proven stems will provide clinicians with useful baseline data with which to compare new stem designs. This study was performed to evaluate the early migration pattern of a hydroxyapatite-coated press-fit femoral component that has been in use for over ten years. We enrolled 30 patients who underwent THA for osteoarthritis. The median age was 70 years (range, 55-80 years). Patients were clinically assessed using the Harris hip score. Radiostereometric analysis was used to evaluate stem migration at three to four days, six months, one year and two years. We observed a mean subsidence of 0.73 mm at six months, 0.62 mm at one year and 0.58 mm at two years and a mean retroversion of 1.82° at six months, 1.90° at one year and 1.59° at two years. This data suggests that subsidence is confined to the first six months after which there was no further subsidence. The results from this study can be compared with those from novel cementless stem designs to help predict the long-term outcome one may expect from new cementless stem designs. PMID:20012862

  20. Stem Cells and Calcium Phosphate Cement Scaffolds for Bone Regeneration

    PubMed Central

    Wang, P.; Zhao, L.; Chen, W.; Liu, X.; Weir, M.D.; Xu, H.H.K.

    2014-01-01

    Calcium phosphate cements (CPCs) have excellent biocompatibility and osteoconductivity for dental, craniofacial, and orthopedic applications. This article reviews recent developments in stem cell delivery via CPC for bone regeneration. This includes: (1) biofunctionalization of the CPC scaffold, (2) co-culturing of osteoblasts/endothelial cells and prevascularization of CPC, (3) seeding of CPC with different stem cell species, (4) human umbilical cord mesenchymal stem cell (hUCMSC) and bone marrow MSC (hBMSC) seeding on CPC for bone regeneration, and (5) human embryonic stem cell (hESC) and induced pluripotent stem cell (hiPSC) seeding with CPC for bone regeneration. Cells exhibited good attachment/proliferation in CPC scaffolds. Stem-cell-CPC constructs generated more new bone and blood vessels in vivo than did the CPC control without cells. hUCMSCs, hESC-MSCs, and hiPSC-MSCs in CPC generated new bone and blood vessels similar to those of hBMSCs; hence, they were viable cell sources for bone engineering. CPC with hESC-MSCs and hiPSC-MSCs generated new bone two- to three-fold that of the CPC control. Therefore, this article demonstrates that: (1) CPC scaffolds are suitable for delivering cells; (2) hUCMSCs, hESCs, and hiPSCs are promising alternatives to hBMSCs, which require invasive procedures to harvest with limited cell quantity; and (3) stem-cell-CPC constructs are highly promising for bone regeneration in dental, craniofacial, and orthopedic applications. PMID:24799422

  1. Stem Cells and Calcium Phosphate Cement Scaffolds for Bone Regeneration.

    PubMed

    Wang, P; Zhao, L; Chen, W; Liu, X; Weir, M D; Xu, H H K

    2014-07-01

    Calcium phosphate cements (CPCs) have excellent biocompatibility and osteoconductivity for dental, craniofacial, and orthopedic applications. This article reviews recent developments in stem cell delivery via CPC for bone regeneration. This includes: (1) biofunctionalization of the CPC scaffold, (2) co-culturing of osteoblasts/endothelial cells and prevascularization of CPC, (3) seeding of CPC with different stem cell species, (4) human umbilical cord mesenchymal stem cell (hUCMSC) and bone marrow MSC (hBMSC) seeding on CPC for bone regeneration, and (5) human embryonic stem cell (hESC) and induced pluripotent stem cell (hiPSC) seeding with CPC for bone regeneration. Cells exhibited good attachment/proliferation in CPC scaffolds. Stem-cell-CPC constructs generated more new bone and blood vessels in vivo than did the CPC control without cells. hUCMSCs, hESC-MSCs, and hiPSC-MSCs in CPC generated new bone and blood vessels similar to those of hBMSCs; hence, they were viable cell sources for bone engineering. CPC with hESC-MSCs and hiPSC-MSCs generated new bone two- to three-fold that of the CPC control. Therefore, this article demonstrates that: (1) CPC scaffolds are suitable for delivering cells; (2) hUCMSCs, hESCs, and hiPSCs are promising alternatives to hBMSCs, which require invasive procedures to harvest with limited cell quantity; and (3) stem-cell-CPC constructs are highly promising for bone regeneration in dental, craniofacial, and orthopedic applications. PMID:24799422

  2. An investigation on the effect of groove geometry on cementless femoral stem component in hip arthroplasty.

    PubMed

    Rawal, B R; Bhatnagar, Naresh

    2013-12-15

    The optimal surface for a cementless femoral stem has been a subject of debate for the past several years. Several researchers have stressed the need for research on how an implant surface shape contributes to long-term stability after implantation, in the field of orthopaedics. The introduction of optimized grooves on an implant proximal surface may enhance long-term stability of an implant. This study thus analyzes the effect of different groove dimensions and angles in a transverse plane on stress transmission by a constant load at the femur by using Finite Element Analysis (FEA). Results suggest that the tendency of stress transmission differs depending on the size, position and angle of the grooves. An optimized groove size and inclination plays a vital role for long-term stability of cementless femoral stems. PMID:24517034

  3. Application of bone marrow mesenchymal stem cells to the treatment of osteonecrosis of the femoral head

    PubMed Central

    Wang, Cheng; Wang, Yu; Meng, Hao-Ye; Yuan, Xue-Ling; Xu, Xiao-Long; Wang, Ai-Yuan; Guo, Quan-Yi; Peng, Jiang; Lu, Shi-Bi

    2015-01-01

    Osteonecrosis of the femoral head (ONFH) is a type of common and refractory disease in the orthopedic clinic that is primarily caused by a partial obstruction of the blood supply to the femoral head, resulting in a series of pathological processes. Mesenchymal stem cells (MSCs) comprise a mixture of various stem cells in myeloid tissue with multipotential differentiation capacity. They can differentiate into bone cells under specific conditions and can be used to treat ONFH through cell transplantation. This review summarizes research on MSCs in the field of ONFH in recent years, reveals the inner characteristics of MSCs, describes their potential to treat osteonecrosis disease, and analyzes the existing challenges of using MSCs in clinical applications. PMID:26064202

  4. Study of bone remodeling of two models of femoral cementless stems by means of DEXA and finite elements

    PubMed Central

    2010-01-01

    Background A hip replacement with a cemented or cementless femoral stem produces an effect on the bone called adaptive remodelling, attributable to mechanical and biological factors. All of the cementless prostheses designs try to achieve an optimal load transfer in order to avoid stress-shielding, which produces an osteopenia. Long-term densitometric studies taken after implanting ABG-I and ABG-II stems confirm that the changes made to the design and alloy of the ABG-II stem help produce less proximal atrophy of the femur. The simulation with FE allowed us to study the biomechanical behaviour of two stems. The aim of this study was, if possible, to correlate the biological and mechanical findings. Methods Both models with prostheses ABG-I and II have been simulated in five different moments of time which coincide with the DEXA measurements: postoperative, 6 months, 1, 3 and 5 years, in addition to the healthy femur as the initial reference. For the complete comparative analysis of both stems, all of the possible combinations of bone mass (group I and group II of pacients in two controlled studies for ABG-I and II stems, respectively), prosthetic geometry (ABG-I and ABG-II) and stem material (Wrought Titanium or TMZF) were simulated. Results and Discussion In both groups of bone mass an increase of stress in the area of the cancellous bone is produced, which coincides with the end of the HA coating, as a consequence of the bottleneck effect which is produced in the transmission of loads, and corresponds to Gruen zones 2 and 6, where no osteopenia can be seen in contrast to zones 1 and 7. Conclusions In this study it is shown that the ABG-II stem is more effective than the ABG-I given that it generates higher tensional values on the bone, due to which proximal bone atrophy diminishes. This biomechanical behaviour with an improved transmission of loads confirmed by means of FE simulation corresponds to the biological findings obtained with Dual-Energy X

  5. Osteointegration of femoral stem prostheses with a bilayered calcium phosphate coating.

    PubMed

    Goyenvalle, Eric; Aguado, Eric; Nguyen, Jean-Michel; Passuti, Norbert; Le Guehennec, Laurent; Layrolle, Pierre; Daculsi, Guy

    2006-03-01

    Our purpose was to evaluate the osteointegration of bilayered calcium phosphate (CaP)-coated femoral hip stems in a canine model. A first layer of hydroxyapatite (HA) 20 microm thick and a superficial layer of Biphasic Calcium Phosphate (BCP) 30 microm thick were plasma-sprayed on to the proximal region of sandblasted Ti6Al4V prostheses. Bilayered CaP-coated and non-coated canine femoral stems were implanted bilaterally under general anesthesia in 6 adult female Beagle dogs. After 6 and 12 months, a significant degradation of the bilayered coating occurred with a remainder of 33.1+/-12.4 and 23.6+/-9.2 microm in thickness, respectively. Lamellar bone apposition was observed on bilayered coated implants while fibrous tissue encapsulation was observed on non-coated femoral stems. The bone-implant contacts (BIC) were 91+/-3% and 81+/-8% for coated and 7+/-8% and 8+/-12% for non-coated implants, at 6 and 12 months, respectively. Our study supports the concept of a direct relationship between the biodegradation of CaP coating and the enhanced osteointegration of titanium prostheses. A bilayered CaP coating might therefore enhance bone apposition in the early stages because of the superior bioactivity of the BCP layer while the more stable HA layer might sustain bone bonding over long periods. PMID:16139882

  6. Theoretical and practical aspects in total uncemented hip arthroplasty by using short femoral stem prosthesis

    PubMed Central

    Moga, M; Pogarasteanu, ME; Barbilian, A

    2015-01-01

    Hip arthrosis, primary or secondary, is an osteoarthritic degenerative process that affects the hip joint. Primary hip arthrosis has an unknown etiology, and secondary hip arthrosis has well defined causes; of these causes, some are known to lead to arthrosis of the hip in the young age patient. The surgical treatment aims either to preserve the patient’s hip joint, or to replace the joint. The most commonly used procedure at this time is the total hip arthroplasty. The femoral component may have a short or a long stem. The short femoral stem prosthesis is usually impacted by using a unique technique and unique instruments, according to the manufacturer’s specifications. There are several models of short stem femoral prosthesis, but no matter which one is chosen, the surgical indication, the surgical technique and a well-conducted recovery program are important. The choosing of each arthroplastic implant must be made with care, taking into consideration the patient’s benefit, his expectations, and also the surgeon’s experience. PMID:26103643

  7. Primary Stability Recognition of the Newly Designed Cementless Femoral Stem Using Digital Signal Processing

    PubMed Central

    Salleh, Sh-Hussain; Hamedi, Mahyar; Zulkifly, Ahmad Hafiz; Lee, Muhammad Hisyam; Mohd Noor, Alias; Harris, Arief Ruhullah A.; Abdul Majid, Norazman

    2014-01-01

    Stress shielding and micromotion are two major issues which determine the success of newly designed cementless femoral stems. The correlation of experimental validation with finite element analysis (FEA) is commonly used to evaluate the stress distribution and fixation stability of the stem within the femoral canal. This paper focused on the applications of feature extraction and pattern recognition using support vector machine (SVM) to determine the primary stability of the implant. We measured strain with triaxial rosette at the metaphyseal region and micromotion with linear variable direct transducer proximally and distally using composite femora. The root mean squares technique is used to feed the classifier which provides maximum likelihood estimation of amplitude, and radial basis function is used as the kernel parameter which mapped the datasets into separable hyperplanes. The results showed 100% pattern recognition accuracy using SVM for both strain and micromotion. This indicates that DSP could be applied in determining the femoral stem primary stability with high pattern recognition accuracy in biomechanical testing. PMID:24800230

  8. Primary stability recognition of the newly designed cementless femoral stem using digital signal processing.

    PubMed

    Baharuddin, Mohd Yusof; Salleh, Sh-Hussain; Hamedi, Mahyar; Zulkifly, Ahmad Hafiz; Lee, Muhammad Hisyam; Mohd Noor, Alias; Harris, Arief Ruhullah A; Abdul Majid, Norazman

    2014-01-01

    Stress shielding and micromotion are two major issues which determine the success of newly designed cementless femoral stems. The correlation of experimental validation with finite element analysis (FEA) is commonly used to evaluate the stress distribution and fixation stability of the stem within the femoral canal. This paper focused on the applications of feature extraction and pattern recognition using support vector machine (SVM) to determine the primary stability of the implant. We measured strain with triaxial rosette at the metaphyseal region and micromotion with linear variable direct transducer proximally and distally using composite femora. The root mean squares technique is used to feed the classifier which provides maximum likelihood estimation of amplitude, and radial basis function is used as the kernel parameter which mapped the datasets into separable hyperplanes. The results showed 100% pattern recognition accuracy using SVM for both strain and micromotion. This indicates that DSP could be applied in determining the femoral stem primary stability with high pattern recognition accuracy in biomechanical testing. PMID:24800230

  9. Laser etching causing fatigue fracture at the neck–shoulder junction of an uncemented femoral stem: A case report

    PubMed Central

    Jang, Bob; Kanawati, Andrew; Brazil, Declan; Bruce, Warwick

    2013-01-01

    Fatigue fracture of a femoral component in total hip arthroplasty is a rare occurrence but well documented in the literature. It is understood that proximal loosing of a femoral stem with a well fixed stem distally will result in cantilever bending and eventual fatigue fracture of the stem. Other factors which may potentiate a fatigue fracture are material design, implant positioning, and patient characteristics. More recently, laser etching on the femoral neck of an implant has resulted in fatigue fracture. We report a case of a fatigue fracture at the neck–shoulder junction in a well fixed, uncemented, femoral component due to laser etching in the region of high tensile stress. PMID:24403758

  10. Three-dimensional shape optimization of a cemented hip stem and experimental validations.

    PubMed

    Higa, Masaru; Tanino, Hiromasa; Nishimura, Ikuya; Mitamura, Yoshinori; Matsuno, Takeo; Ito, Hiroshi

    2015-03-01

    This study proposes novel optimized stem geometry with low stress values in the cement using a finite element (FE) analysis combined with an optimization procedure and experimental measurements of cement stress in vitro. We first optimized an existing stem geometry using a three-dimensional FE analysis combined with a shape optimization technique. One of the most important factors in the cemented stem design is to reduce stress in the cement. Hence, in the optimization study, we minimized the largest tensile principal stress in the cement mantle under a physiological loading condition by changing the stem geometry. As the next step, the optimized stem and the existing stem were manufactured to validate the usefulness of the numerical models and the results of the optimization in vitro. In the experimental study, strain gauges were embedded in the cement mantle to measure the strain in the cement mantle adjacent to the stems. The overall trend of the experimental study was in good agreement with the results of the numerical study, and we were able to reduce the largest stress by more than 50% in both shape optimization and strain gauge measurements. Thus, we could validate the usefulness of the numerical models and the results of the optimization using the experimental models. The optimization employed in this study is a useful approach for developing new stem designs. PMID:25320015

  11. A High Prevalence of Corrosion at the Head-Neck Taper with Contemporary Zimmer Non-Cemented Femoral Hip Components.

    PubMed

    McGrory, Brian J; MacKenzie, Johanna; Babikian, George

    2015-07-01

    Mechanically assisted crevice corrosion (MACC) occurs at metal/metal modular junctions in which at least one of the components is fabricated from cobalt-chromium alloy and may lead to adverse local tissue reaction (ALTR) in patients with metal-on-polyethylene (MoP) total hip arthroplasty. This type of reaction has been previously described in hips with head/neck modularity, but the prevalence is unknown. We found a prevalence of 1.1 percent in a consecutive series of 1356 contemporary Zimmer non-cemented femoral hip components followed for a minimum of 2years. The average time to presentation was 3.7years (range, 9-105months); delay in treatment led to irreversible soft tissue damage in three patients. We recommend usage of ceramic heads until this problem is further understood. PMID:25737386

  12. Periprosthetic fractures around the femoral stem: overcoming challenges and avoiding pitfalls

    PubMed Central

    Chen, Antonia F.

    2015-01-01

    Management of periprosthetic fractures around the femoral stem after total hip arthroplasty (THA) represents a significant challenge and optimal treatment remains controversial. The most common treatment paradigm involves treating fractures around a well-fixed stem with osteosynthesis, whereas fractures around a loose stem require revision arthroplasty and those with poor bone require augmentation with bone graft. Paradoxically, the literature reports a higher rate of failure for osteosynthesis around prostheses considered to be well-fixed. Such a high rate of poor outcomes may result not only from difficult fracture fixation and compromised biologic healing, but also from unrecognized peri-implant pathology. Therefore, proper preoperative and intraoperative evaluation is key, and a subset of patients may benefit from alternative management. We review the appropriate methods for evaluation and treatment of Vancouver type B fractures with particular emphasis on avoiding missteps that can lead to failure. PMID:26539451

  13. Subsidence in two uncemented femoral stems: an in vitro study.

    PubMed

    Sotereanos, Nicholas G; Wohlrab, David; Hofer, Andre; Kuxhaus, Laurel; Miller, Mark Carl

    2013-10-01

    Many aspects of the performance of different implant designs remain as open questions in total hip arthroplasty. Despite the increased survivorship of each hip replacement, the amount of bone removed during surgery remains an important factor because of the potential need for revision surgery. Given that a smaller implant will have less surface area over which to transfer load, constructs that preserve more bone stock may be susceptible to mechanical complications related to the fixation of the implant in the femur. To assess mechanical fixation, this study compared the fiber metal taper and Mayo conservative hip stems in subsidence, frontal plane rotation and failure load. After dual-energy x-ray absorptiometry scans, pairs of cadaveric femurs received implants of each type and were loaded for 10,000 cycles. The subsidence and rotation were measured. Finally, specimens were loaded to failure. The subsidence and rotation after cyclic loading were -0.73 mm and 0.1°, respectively, for the Mayo implants and -0.87 and 0.52°, respectively, for the fiber metal taper implants, but no significant differences between implant types were found. There was also no significant relationship to bone mineral density. A power analysis revealed that 914 specimens would have been required to achieve a power of 0.8. PMID:23804948

  14. No medium-term advantage of electrochemical deposition of hydroxyapatite in cementless femoral stems

    PubMed Central

    Flatøy, Bernhard; Röhrl, Stephan M; Bøe, Berte; Nordsletten, Lars

    2016-01-01

    Background and purpose Hydroxyapatite has been used for a long time as an adjunct to enhance cementless fixation. The benefit of this is still debated, but new methods of hydroxyapatite deposition have emerged, offering possible gains. In order to investigate this further, we compared the migration pattern and periprosthetic bone remodeling in a cementless femoral stem with either electrochemically deposited hydroxyapatite—called Bonemaster (BM)—or a conventional plasma-sprayed hydroxyapatite (HA) coating. Patients and methods 55 hips were randomized to either BM or HA cementless femoral stems. Patients were followed with radiostereometry (RSA), dual-energy X-ray absorptiometry (DXA), radiographic measurements, and hip questionnaires for 5 years. Results For both stems, migration occurred mainly as subsidence and retroversion during the first 3 months. The BM group had a higher retroversion rate of 0.17° per month during this period, as compared to 0.06° per month for the HA group (p = 0.006). Thereafter, there was almost no movement in any direction for both stem types. Bone resorption occurred mainly during the first year, and subsequently decreased to a rate close to what is seen in normal ageing. The greatest total decrease occurred in Gruen zones 1 and 7, similar in the groups at 5 years. There was a slightly higher resorption rate in Gruen zone 7 from 2 to 5 years in the BM group (1.3% per year; p = 0.04), but in a magnitude that would scarcely affect stem stability or survival. Interpretation There were no clinically relevant differences between the 2 stems regarding stability or periprosthetic bone loss at 5 years. Electrochemically deposited HA does not appear to affect fixation or bone remodeling when compared to conventional plasma spraying at 5 years. Thus, at this point, Bonemaster appears to be safe. PMID:26364953

  15. Morphological and functional characterization of femoral head drilling-derived mesenchymal stem cells.

    PubMed

    Tatu, Romulus Fabian; Anuşca, Dan Nelu; Groza, Sabine Ştefania; Marusciac, Laura; Bojin, Florina Maria; Tatu, Carmen; Hurmuz, Mihai; Păunescu, Virgil

    2014-01-01

    Adult mesenchymal stem cells (MSCs) were primary identified as bone marrow-derived cells, fibroblast-like morphology, and adherent to plastic surfaces of in vitro culture plate. Their identification criteria evolved in time to a well-established panel of markers (expression of CD73, CD90, and CD105) and functional characteristics (adipogenic, osteogenic, and chondrogenic trilineage differentiation ability), which can be applied to adult mesenchymal stem cells obtained from other tissue sources. We tried to assess the potential stemness of femoral head drilling-derived cells as a new source of mesenchymal stem cells (FH-MSCs). For this purpose, we used the morphological and ultrastructural characteristics defined by scanning and transmission electron microscopy and spindle-shape cellular body, fibroblast-like, with few thick elongations (lamellipodia) and numerous fine, thin cytoplasmic projections (filopodia) that extend beyond the edge of lamellipodia. Immunophenotypical analysis was performed by flow cytometry and immunocytochemical methods and we showed that FH-MSCs share the characteristic markers of MSCs, expressing CD73, CD90, CD105, and being positive for vimentin, and c-kit (CD117). Proliferation rate of these cells was moderate, as revealed by Ki67 immunostaining. Regarding the functional characteristics of FH-MSCs, after appropriate time of induction in specific culture media, the cells were able to prove their trilineage potential and differentiated towards adipocytic, osteogenic, and chondrogenic lineage, as revealed by immunofluorescent staining. We may conclude that femoral head drilling-derived cells can be used as a novel source of stem cells, and employed in diverse clinical settings. PMID:25611275

  16. Fracture of Fully-coated Femoral Stem after Primary Total Hip Arthroplasty for Nonunion of Intertrochanteric Fracture: A Case Report

    PubMed Central

    Chun, Young Soo; Juh, Hyung Suk; Cho, Yoon Je

    2015-01-01

    Femoral stem fracture is an uncommon reason for the failure of total hip arthroplasty, with only 16 cases of fully coated stem fractures reported to date. Here we report a case in which a fully coated primary femoral stem fracture occurred after conversion to total hip arthroplasty for the non-union of an intertrochanteric fracture of the femur. Metallurgic evaluation of the etiology and mechanism revealed that the fracture was initiated by fatigue-related failure and completed by ductile failure on the posterior side of the fracture. Considering the recent trend of treating an intertrochanteric fracture with hip arthroplasty, possible stem failure should be considered, since most patients will have at least one of the known risk factors for stem fracture. PMID:27536622

  17. Bone ingrowth through porous titanium granulate around a femoral stem: histological assessment in a six-month canine hemiarthroplasty model.

    PubMed

    Turner, Thomas M; Urban, Robert M; Hall, Deborah J; Andersson, Gunnar B J

    2007-01-01

    The procedure of using of porous titanium granules for cementless fixation of a hip replacement femoral stem was studied in a hemiarthroplasty model in 10 canines for 6 months. A vibrating instrument was used to facilitate both the delivery and distribution of the irregularly shaped porous titanium granules into the femoral canal as well as the subsequent insertion of a titanium alloy stem into the intramedullary bed of granules. Histological examination revealed lamellar bone formation through the mantle of porous titanium granules in continuity with the surrounding cortex resulting in the formation of an integrated mantle of bone and titanium granulate around the prosthesis. PMID:17578819

  18. Progressive femoral cortical and cancellous bone density loss after uncemented tapered-design stem fixation

    PubMed Central

    Nowak, Tobias E; Haeberle, Lothar; Mueller, Lars P; Kress, Alexander; Voelk, Michael; Pfander, David; Forst, Raimund; Schmidt, Rainer

    2010-01-01

    Background Aseptic implant loosening and periprosthetic bone loss are major problems after total hip arthroplasty (THA). We present an in vivo method of computed tomography (CT) assisted osteodensitometry after THA that differentiates between cortical and cancellous bone density (BD) and area around the femoral component. Method Cortical and cancellous periprosthetic femoral BD (mg CaHA/mL), area (mm2) and contact area between the prothesis and cortical bone were determined prospectively in 31 patients 10 days, 1 year, and 6 years after uncemented THA (mean age at implantation: 55 years) using CT-osteodensitometry. Results 6 years postoperatively, cancellous BD had decreased by as much as 41% and cortical BD by up to 27% at the metaphyseal portion of the femur; this decrease was progressive between the 1-year and 6-year examinations. Mild cortical hypertrophy was observed along the entire length of the diaphysis. No statistically significant changes in cortical BD were observed along the diaphysis of the stem. Interpretation Periprosthetic CT-assisted osteodensitometry has the technical ability to discriminate between cortical and cancellous bone structures with respect to strain-adapted remodeling. Continuous loss of cortical and cancellous BD at the femoral metaphysis, a homeostatic cortical strain configuration, and mild cortical hypertrophy along the diaphysis suggest a diaphyseal fixation of the implanted stem. CT-assisted osteodensitometry has the potential to become an effective instrument for quality control in THA by means of in vivo determination of periprosthetic BD, which may be a causal factor in implant loosening after THA. PMID:20180716

  19. Periprosthetic DXA after total hip arthroplasty with short vs. ultra-short custom-made femoral stems

    PubMed Central

    Santori, Francesco S; Pavan, Laura; Learmonth, Ian D; Passariello, Roberto

    2009-01-01

    Background and purpose Dual-energy X-ray absorptiometry (DXA) analysis of the 7 periprosthetic Gruen zones is the most commonly used protocol to evaluate bone remodeling after the implantation of conventional femoral stems. We assessed the value of DXA after cementless primary total hip arthroplasty (THA) by comparing the effect of progressive shortening of the stem of two femoral implants on periprosthetic bone remodeling using a specifically developed protocol of analysis with 5 periprosthetic regions of interest (ROIs). Patients and methods Bone mineral density (BMD) was evaluated in 37 patients in the plateau stage, 3 years after THA. Two femoral implants featuring conceptually new designs and surgical technique were tested: types 1 and 2, characterized by extremely short stem and virtual absence of distal stem, respectively. Results We found that progressive shortening of the femoral stem produces more proximal loading, which effectively preserves metaphyseal bone stock and increases periprosthetic BMD in the medial ROIs over time. In the type 2 group, higher absolute BMD values were observed in medial ROIs 4 and 5. No differences were found in ROIs 1, 2, and 3. Interpretation This study shows the flexibility of DXA in adapting the protocol of periprosthetic analysis to the specific requirements of new implant designs, and it shows its high sensitivity in evaluation of the biological response of bone to changes in implant shape. PMID:19562565

  20. Cement augmentation of implants--no general cure in osteoporotic fracture treatment. A biomechanical study on non-displaced femoral neck fractures.

    PubMed

    Hofmann-Fliri, Ladina; Nicolino, Tomas I; Barla, Jorge; Gueorguiev, Boyko; Richards, R Geoff; Blauth, Michael; Windolf, Markus

    2016-02-01

    Femoral neck fractures in the elderly are a common problem in orthopedics. Augmentation of screw fixation with bone cement can provide better stability of implants and lower the risk of secondary displacement. This study aimed to investigate whether cement augmentation of three cannulated screws in non-displaced femoral neck fractures could increase implant fixation. A femoral neck fracture was simulated in six paired human cadaveric femora and stabilized with three 7.3 mm cannulated screws. Pairs were divided into two groups: conventional instrumentation versus additional cement augmentation of screw tips with 2 ml TraumacemV+ each. Biomechanical testing was performed by applying cyclic axial load until failure. Failure cycles, axial head displacement, screw angle changes, telescoping and screw cut-out were evaluated. Failure (15 mm actuator displacement) occurred in the augmented group at 12,500 cycles (± 2,480) compared to 15,625 cycles (± 4,215) in the non-augmented group (p = 0.041). When comparing 3 mm vertical displacement of the head no significant difference (p = 0.72) was detected between the survival curves of the two groups. At 8,500 load-cycles (early onset failure) the augmented group demonstrated a change in screw angle of 2.85° (± 0.84) compared to 1.15° (± 0.93) in the non-augmented group (p = 0.013). The results showed no biomechanical advantage with respect to secondary displacement following augmentation of three cannulated screws in a non-displaced femoral neck fracture. Consequently, the indication for cement augmentation to enhance implant anchorage in osteoporotic bone has to be considered carefully taking into account fracture type, implant selection and biomechanical surrounding. PMID:26177609

  1. The influence of uncemented femoral stem length and design on its primary stability: a finite element analysis.

    PubMed

    Reimeringer, M; Nuño, N; Desmarais-Trépanier, C; Lavigne, M; Vendittoli, P A

    2013-01-01

    One of the crucial factors for short- and long-term clinical success of total hip arthroplasty cementless implants is primary stability. Indeed, motion at the bone-implant interface above 40 μm leads to partial bone ingrowth, while motion exceeding 150 μm completely inhibits bone ingrowth. The aim of this study was to investigate the effect of two cementless femoral stem designs with different lengths on the primary stability. A finite element model of a composite Sawbones(®) fourth generation, implanted with five lengths of the straight prosthesis design and four lengths of the curved prosthesis design, was loaded with hip joint and abductor forces representing two physiological activities: fast walking and stair climbing. We found that reducing the straight stem length from 146 to 54 mm increased the average micromotion from 17 to 52 μm during fast walking, while the peak value increased from 42 to 104 μm. With the curved stem, reducing length from 105 to 54 mm increased the average micromotion from 10 to 29 μm, while the peak value increased from 37 to 101 μm. Similar findings are obtained for stair climbing for both stems. Although the present study showed that femoral stem length as well as stem design directly influences its primary stability, for the two femoral stems tested, length could be reduced substantially without compromising the primary stability. With the aim of minimising surgical invasiveness, newer femoral stem design and currently well performing stems might be used with a reduced length without compromising primary stability and hence, long-term survivorship. PMID:22452543

  2. Revision arthroplasty for periprosthetic femoral fracture using an uncemented modular tapered conical stem.

    PubMed

    da Assunção, R E; Pollard, T C B; Hrycaiczuk, A; Curry, J; Glyn-Jones, S; Taylor, A

    2015-08-01

    Periprosthetic femoral fracture (PFF) is a potentially devastating complication after total hip arthroplasty, with historically high rates of complication and failure because of the technical challenges of surgery, as well as the prevalence of advanced age and comorbidity in the patients at risk. This study describes the short-term outcome after revision arthroplasty using a modular, titanium, tapered, conical stem for PFF in a series of 38 fractures in 37 patients. The mean age of the cohort was 77 years (47 to 96). A total of 27 patients had an American Society of Anesthesiologists grade of at least 3. At a mean follow-up of 35 months (4 to 66) the mean Oxford Hip Score (OHS) was 35 (15 to 48) and comorbidity was significantly associated with a poorer OHS. All fractures united and no stem needed to be revised. Three hips in three patients required further surgery for infection, recurrent PFF and recurrent dislocation and three other patients required closed manipulation for a single dislocation. One stem subsided more than 5 mm but then stabilised and required no further intervention. In this series, a modular, tapered, conical stem provided a versatile reconstruction solution with a low rate of complications. PMID:26224817

  3. Analysis of bone mineralization on uncemented femoral stems by [18F]-fluoride-PET

    PubMed Central

    2013-01-01

    Purpose We present the first study using fluoride-positron emission CT (F-PET/CT) to analyze mineralization of bone in the femur adjacent to uncemented stems following total hip arthroplasty (THA). We studied patients who were operated bilaterally for osteoarthritis with 2 different stems during the same surgical session. Patients and methods THA was performed bilaterally during the same surgical session in 8 patients with bilateral osteoarthritis of the hip. An SL-PLUS stem was inserted in one hip and a BetaCone stem was inserted in the contralateral hip, with randomization of side and sequence. A second group of 12 individuals with a normal healthy hip was used as reference for normal bone metabolism. Clinical and radiographic evaluation was performed preoperatively, postoperatively, and at 2 years. We used [18F]-fluoride-PET/CT to analyze bone mineralization adjacent to the stems 1 week, 4 months, and 12 months after surgery. We modified the Polar Map system to fit the upper femur for analysis and presentation of the PET results from 12 regions of interest adjacent to the whole stem. Results The clinical results were good at 2 years. By radiography, all stems were stable. At PET analyses 1 week after surgery, the activity was higher for the SL-PLUS group than for the BetaCone group. The activity was statistically significantly higher for both stems than the reference values at 4 months, and was most pronounced in the upper femur. At one year, the activity had declined more for the BC group than for the SL group. Interpretation The bone mineralization activity varied between different regions for the same stem and between different time periods for each group. F-PET/CT is a novel and valuable tool for analysis of bone mineralization patterns around uncemented femoral stems in detail. The combination of PET/CT analysis and the modified Polar Map system may provide a useful tool for future studies of metabolic bone responses to prosthetic implants. PMID:23506163

  4. Similar effect of stem geometry on radiological changes with 2 types of cemented straight stem

    PubMed Central

    Clauss, Martin; Bolliger, Lilianna; Brandenberger, Daniel; Ochsner, Peter E; Ilchmann, Thomas

    2016-01-01

    Background and purpose — There are 2 basic principles in cemented stem fixation: shape-closed and force-closed. We investigated 2 shape-closed straight stems, the Müller (MSS) and the Virtec (VSS), which differ only in geometrical cross section, to determine whether the difference in stem shape would affect the radiological results or long-term survival. Patients and methods — We included 711 hips (in 646 patients) that were operated on between July 1996 and July 2003. Patients randomly received either an MSS (n = 356) or a VSS (n = 355) and were followed prospectively. Radiographs taken at a follow-up of > 10 years were analyzed for osteolysis. Kaplan-Meier (KM) survival analysis was performed using various endpoints. We also performed Cox regression analysis to identify risk factors for aseptic loosening and osteolysis of the stem. Results — After 10 years, KM survival with “revision of any component for any reason” was 92% (95% CI: 88–95) for the MSS and 95% (CI: 92–97) for the VSS (p = 0.1). With “revision for aseptic loosening of the stem” as the endpoint, KM survival was 96% (CI: 9–98) for the MSS and 98% (CI: 97–100) for the VSS (p = 0.2). Cox regression showed that none of the risk factors analyzed were independent regarding aseptic loosening of the stem or regarding osteolysis. Interpretation — The MSS and the VSS showed excellent survival for aseptic loosening after 10 years. For the 2 different stem designs, we did not find any independent risk factors for aseptic loosening or development of osteolysis. PMID:26471977

  5. [Surgical treatment of a displaced femoral head fracture with a cement-free dual-headed prosthesis using a minimally invasive approach. Clinical and radiographic outcome].

    PubMed

    Wick, M; Muhr, G; Rincon, R; Lester, D

    2005-03-01

    One hundred patients treated with a cementless bipolar prosthesis for a displaced subcapital hip fracture were prospectively evaluated for clinical and radiographic outcome. All patients were operated via a minimally invasive approach; in every case we implanted a Zweymuller stem. There were 77 women and 33 men with a mean age of 80 years (29-98 years). The mean duration of the operation was 29 min (20-95 min). Full weight bearing on crutches was allowed 1 day after the operation. The mean follow-up was 2.5 years (6 months to 7 years). Two years after the operation there were 40% of the remaining 65 patients who scored between 90 and 100 on the Harris hip score, 23% between 80 and 89, 20% between 70 and 79, and 17% below 70. No patient complained about thigh pain and up to now there has been no need for femoral revision due to loosening. There was no infection or nerve lesion. In three patients there was a luxation of the prosthesis which could be reduced by closed means. Radiographs from 81 patients showed stress shielding in 97.5% mainly in Gruen zones 1 and 7. Radiolucent lines in two or more Gruen zones were found in two patients. These findings suggest that the noncemented, pressfit, grit-blasted bipolar prosthesis demonstrated similar stability and radiographic results to cemented bipolar prostheses. Stress shielding was common but did not influence longevity of the implant. We did not find any signs of protrusion. Especially in older patients with a history of cardiac disease, the noncemented bipolar prosthesis is a rational alternative to avoid intra- and postoperative complications despite the higher costs for the implant. The minimally invasive approach helps to reduce operation time and intraoperative blood loss. PMID:15778832

  6. Prospective randomised clinical trial assessing subsidence and rotation, using radiostereometric analysis, of two modular cementless femoral stems (Global K2 and Apex)

    PubMed Central

    Edmondson, Mark; Ebert, Jay; Nivbrant, Oscar; Wood, David

    2014-01-01

    Aims To accurately assess subsidence, rotation and clinical scores in two cementless femoral stems. Methods 260 patients received either K2 or Apex femoral stems and were studied over 2y, with RSA and clinical scores. Results Mean Oxford Hip score for both stems was excellent (45.78 and 46.76). Very little subsidence or rotation were noted on RSA in either stem. There were no statistically significant differences in clinical scores, or radiological motion between stems. Revision rate was 0.8% over the study period. Conclusion Excellent clinical and RSA scores over the 2y study period predict good long term outcomes for these stems. PMID:25104894

  7. The contribution of the nonporous distal stem to the stability of proximally porous-coated canine femoral components.

    PubMed

    Jasty, M; Krushell, R; Zalenski, E; O'Connor, D; Sedlacek, R; Harris, W

    1993-02-01

    The contribution of the distal nonporous-coated stem to the stability of the uncemented femoral components, which were porous coated only proximally, was investigated under two conditions: (1) immediately after insertion and (2) at 6 months, 1 year, and 2 years after surgery in a canine model. The relative motion of the femoral components at the bone porous-coating interface under loads simulating the canine midstance was measured at these time periods using displacement transducers. The measurements were repeated after severing the connection between the porous-coated proximal body and the nonporous-coated distal stem through a small hole in the anterior cortex. The results showed that while the distal nonporous-coated stem enhanced the immediate stability of the proximally porous-coated uncemented femoral components, it contributed little to the long-term stability of the femoral components after bony ingrowth had occurred in vivo. The mean relative motion between the body of the prosthesis and the cortical bone increased from 12 microns (+/- 7 microns) to 31 microns (+/- 34 microns) in the posterior transverse direction when the stem was immediately severed after the surgery. However, at 6 months, 1 year, and 2 years after surgery, extensive bone ingrowth had occurred into the proximal porous-coated regions of the body and provided excellent stability to the femoral components. With bone ingrowth, the mean relative motion was less than 5 microns at any site. Under these conditions, severing the stem did not increase the relative motion of the prostheses significantly.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8436987

  8. Stemmed femoral knee prostheses: effects of prosthetic design and fixation on bone loss.

    PubMed

    van Lenthe, G Harry; Willems, Marieke M M; Verdonschot, Nico; de Waal Malefijt, Maarten C; Huiskes, Rik

    2002-12-01

    Although the revision rates for modern knee prostheses have decreased drastically, the total number of revisions a year is increasing because many more primary knee replacements are being done. At the time of revision, bone loss is common, which compromises prosthetic stability. To improve stability, intramedullary stems are often used. The aim of this study was to estimate the effects of a stem, its diameter and the interface bonding conditions on patterns of the bone remodeling in the distal femur. We created finite element models of the distal half of a femur in which 4 types of knee prostheses were placed. The bone remodeling process was simulated using a strain-adaptive bone remodeling theory. The amount of such remodeling was determined by calculating the changes in bone mineral density in 9 regions of interest from simulated DEXA scans. The computer simulation model showed that revision prostheses tend to cause more bone resorption than primary ones, especially in the most distal regions. Predicted long-term bone loss due to a revision prosthesis with a thin stem equalled that around a prosthesis with an intercondylar box. However, strong regional differences were found--the stemmed prostheses having more bone loss in the most distal areas and some bone gain in the more proximal ones. A prosthesis with a thick stem led to an increase in bone loss. When the prosthesis-cement interface was bonded, more bone loss was predicted than with an unbonded interface. These results suggest that a stem which increases stability initially may reduce stability in the long term. This is due to an increase in stress shielding and bone resorption. PMID:12553509

  9. Neck fracture of a cementless forged titanium alloy femoral stem following total hip arthroplasty: a case report and review of the literature

    PubMed Central

    Grivas, Theodoros B; Savvidou, Olga D; Psarakis, Spyridon A; Bernard, Pierre-Francois; Triantafyllopoulos, George; Kovanis, Ioannis; Alexandropoulos, Panagiotis

    2007-01-01

    Introduction Fractures of the neck of the femoral component have been reported in uncemented total hip replacements, however, to our knowledge, no fractures of the neck of a cementless forged titanium alloy femoral stem coated in the proximal third with hydroxy-apatite have been reported in the medical literature. Case presentation This case report describes a fracture of the neck of a cementless forged titanium alloy stem coated in the proximal third with hydroxy-apatite. Conclusion The neck of the femoral stem failed from fatigue probably because of a combination of factors described analytically below. PMID:18062807

  10. Inter-subject variability effects on the primary stability of a short cementless femoral stem.

    PubMed

    Bah, Mamadou T; Shi, Junfen; Heller, Markus O; Suchier, Yanneck; Lefebvre, Fabien; Young, Philippe; King, Leonard; Dunlop, Doug G; Boettcher, Mick; Draper, Edward; Browne, Martin

    2015-04-13

    This paper is concerned with the primary stability of the Furlong Evolution(®) cementless short stem across a spectrum of patient morphology. A computational tool is developed that automatically selects and positions the most suitable stem from an implant system made of a total of 48 collarless stems to best match a 3D model based on a library of CT femur scans (75 males and 34 females). Finite Element contact models of reconstructed hips, subjected to physiologically-based boundary constraints and peak loads of walking mode, were simulated using a coefficient of friction of 0.4 and an interference-fit of 50 μm. Maximum and average implant micromotions across the subpopulation were predicted to be 100±7 μm and 7±5 μm with ranges [15 μm, 350 μm] and [1 μm, 25 μm], respectively. The computed percentage of implant area with micromotions greater than reported critical values of 50 μm, 100 μm and 150 μm never exceeded 14%, 8% and 7%, respectively. To explore the possible correlations between anatomy and implant performance, response surface models for micromotion metrics were constructed. Detailed morphological analyses were conducted and a clear nonlinear decreasing trend was observed between implant average micromotion and both the metaphyseal canal flare indices and average densities in Gruen zones. The present study demonstrates that the primary stability and tolerance of the short stem to variability in patient anatomy were high, reducing the need for patient stratification. In addition, the developed tool could be utilised to support implant design and planning of femoral reconstructive surgery. PMID:25724937

  11. Survival of Bi-Metric femoral stems in 77 total hip arthroplasties for juvenile chronic arthritis.

    PubMed

    Lybäck, C C; Lybäck, C O; Kyrö, A; Kautiainen, H J; Belt, E A

    2004-12-01

    The survival of 77 cementless total hip arthroplasties using a Bi-Metric femoral stem and two types of acetabular components was analysed in 55 patients with juvenile chronic arthritis. The patients were treated between 1986 and 1996. Their mean age was 8.0 years at the onset of the disease and 28.1 years at the time of surgery. The mean follow-up period was 9.6 years. Follow-up evaluations were conducted 3 months and 1, 4, 8, 12 and 16 years post-operatively. The endpoints of survival analysis were revision surgery, death of the patient or the end of the year 2002. The 10-year survival was 77.6% for the Romanus cup and 49.1% for the TTAP-ST cup. In contrast to these inadequate outcomes, the cementless Bi-Metric stem yielded excellent results with a survival rate of 100% for aseptic loosening during a mean follow-up period of 10 years. PMID:15316677

  12. The Effect of Hydroxyapatite Coating on Long-term Results of Total Hip Arthroplasty with Hydroxyapatite-coated Anatomic Femoral Stem

    PubMed Central

    Im, Chae-Hyun; Kim, Dae-Hee; Heo, Ju-Yeong; Jang, Young-Jae

    2014-01-01

    Purpose To evaluate the clinical and radiological results, as well as the survival rate, associated with total hip arthroplasty using a hydroxyapatite (HA)-coated anatomical femoral stem at a follow-up of ≥12 years. Materials and Methods From April 1992 to May 1997, 86 patients (102 hips) underwent total hip arthroplasty with a HA-coated ABG I (Anatomical Benoist Giraud; Howmedica) hip prosthesis. The average age at the time of surgery was 53.4 years and the mean duration of follow-up was 17.1 years (range, 12.1-21.0 years). The Harris hip score (HHS) and radiographic assessments of thigh pain were used to evaluate the clinical results. We observed osteointegration, cortical hypertrophy, reactive line, calcar resorption and osteolysis around the femoral stems. The survival rate of the femoral stems was evaluated by using the span of time to a revision operation for any reasons was defined as the end point. Results The mean HHS was 50.5 preoperatively and 84.2 at the time of last follow-up. Osteolysis only around the HA-coated proximal portion of the femoral stem was observed in 72 hips, cortical hypertrophy all around the distal portion of the femoral stem was observed in 38 hips, and calcar resorption was observed in 44 hips. A reactive line was observed in 13 hips, but was unrelated to component loosening. Stem revision operations were performed in 24 (23%) hips due to osteolysis (14 hips), fracture (5 hips) and infection (5 hips). The femoral stem survival rate was 75% over the mean duration of follow-up. Conclusion Total hip arthroplasty using a HA-coated anatomical femoral stem showed necessitated a high rate of revision operations due to osteolysis around the femoral stem in this long term follow-up study.

  13. Adverse reaction to metal bearing leading to femoral stem fractures: a literature review and report of two cases

    PubMed Central

    Al-Azzani, Waheeb A.K.; Iqbal, Hafiz J.; John, Alun

    2016-01-01

    Metal-on-metal (MoM) bearing in total hip replacement (THR) has a high failure rate due to adverse reaction to metal debris (ARMD). There is a spectrum of soft tissue and bony changes in ARMD including muscle necrosis and osteolysis. In our institution, more than 1500 MoM THRs were implanted since 2003. Recently, we have revised significant numbers of these. We report our experience and management of a mode of failure of MoM THR that has been infrequently reported—the distal femoral stem fracture. We report on two patients who presented with worsening pain attributable to fracture of the femoral stem. Severe femoral osteolysis led to loss of proximal stem support and eventual fatigue fracture of the component. Both patients were revised employing a posterior approach. Bone trephine was used to extract a well-fixed distal stem fragment without any windows. Both patients had successful outcome after revision with excellent pain relief and no complications. PMID:26846269

  14. [Is instillation of bone marrow stem cells at the time of core decompression useful for osteonecrosis of the femoral head?].

    PubMed

    Cabrolier, Jorge; Molina, Marcelo

    2016-01-01

    Osteonecrosis of the femoral head leads to degeneration of the head and finally to osteoarthritis of the hip. Decompression is the most widely used treatment, but its effectiveness is limited. It has been proposed instillation of stem cells in addition to decompression, would lead to better results. Searching in Epistemonikos database, which is maintained by screening 30 databases, we identified two systematic reviews including two randomized trials. We combined the evidence using meta-analysis and generated a summary of findings table following the GRADE approach. We concluded instillation of bone marrow stem cells at the time of core decompression probably slows progression to osteoarthritis of the hip in patients with osteonecrosis of the femoral head and might reduce the need of subsequent surgeries. It is unclear whether it has any effect on the functionality because the certainty of the evidence is very low. PMID:27028230

  15. Measurement of transient and residual stresses during polymerization of bone cement for cemented hip implants.

    PubMed

    Nuño, N; Madrala, A; Plamondon, D

    2008-08-28

    The initial fixation of a cemented hip implant relies on the strength of the interface between the stem, bone cement and adjacent bone. Bone cement is used as grouting material to fix the prosthesis to the bone. The curing process of bone cement is an exothermic reaction where bone cement undergoes volumetric changes that will generate transient stresses resulting in residual stresses once polymerization is completed. However, the precise magnitude of these stresses is still not well documented in the literature. The objective of this study is to develop an experiment for the direct measurement of the transient and residual radial stresses at the stem-cement interface generated during cement polymerization. The idealized femoral-cemented implant consists of a stem placed inside a hollow cylindrical bone filled with bone cement. A sub-miniature load cell is inserted inside the stem to make a direct measurement of the radial compressive forces at the stem-cement interface, which are then converted to radial stresses. A thermocouple measures the temperature evolution during the polymerization process. The results show the evolution of stress generation corresponding to volumetric changes in the cement. The effect of initial temperature of the stem and bone as well as the cement-bone interface condition (adhesion or no adhesion) on residual radial stresses is investigated. A maximum peak temperature of 70 degrees C corresponds to a peak in transient stress during cement curing. Maximum radial residual stresses of 0.6 MPa in compression are measured for the preheated stem. PMID:18692188

  16. Biomimetic Calcium-Silicate Cements Support Differentiation Of Human Orofacial Mesenchymal Stem Cells

    PubMed Central

    Gandolfi, Maria Giovanna; Shah, Sara N.; Feng, Ruoxue; Prati, Carlo; Akintoye, Sunday O.

    2011-01-01

    Introduction Human orofacial bone mesenchymal stem cells (OFMSCs) from maxilla and mandible have robust osteogenic regenerative properties based on our previous reports that demonstrate phenotypic and functional differences between jaw and axial bone mesenchymal stem cells in same individuals. Furthermore, a combination of OFMSCs with bioactive calcium-releasing cements can potentially improve OFMSC multi-lineage differentiation capacity, but biocompatibility of calcium silicate cements with OFMSCs is still unclear. We tested the hypothesis that material extracts of calcium-releasing calcium-silicate cements support biomimetic microenvironment for survival and differentiation of human OFMSCs. Methods Two experimental calcium-silicate cements 1) calcium-silicate mineral powder (wTC) containing di- and tricalcium-silicate, calcium sulphate, and calcium chloride and 2) wTC doped with alpha-tricalcium phosphate (wTC-αTCP) were designed and prepared. Cement setting times were assessed by Gilmore needles, ability to release calcium and hydroxyl ions was assessed by potentiometric methods and OFMSC attachment to calcium-silicate discs was assessed. Calcium-silicate material extracts were tested for ability to support OFMSCs survival and in vitro/in vivo differentiation. Results Fewer OFMSCs attached to calcium-silicate discs relative to tissue culture plastic (p=0.001). Extracts of calcium-silicate cements sustained OFMSC survival, maintained steady state levels of vascular cell adhesion molecule-1, alkaline phosphatase and bone sialoprotein while upregulating their respective gene transcripts. Adipogenic and in vivo bone regenerative capacities of OFMSCs were also unaffected by calcium-silicate extracts. Conclusions Ion-releasing calcium-silicate cements support a biomimetic microenvironment conducive to survival and differentiation of OFMSCs. Combination of OFMSCs and calcium-silicate cement can potentially promote tissue regeneration in periapical bone defects. PMID

  17. The impact of proximal femoral morphology on failure strength with a mid-head resection short-stem hip arthroplasty.

    PubMed

    Olsen, Michael; Al Saied, Mohamed; Morison, Zachary; Sellan, Michael; Waddell, James P; Schemitsch, Emil H

    2014-12-01

    Mid-head resection short-stem hip arthroplasty is a conservative alternative to conventional total hip replacement and addresses proximal fixation challenges in patients not suitable for hip resurfacing. It is unclear whether proximal femoral morphology impacts the ultimate failure load of mid-head resection implanted femurs, thus the aim of this study was to investigate the effect of native neck-shaft angle (NSA) and coronal implant alignment on proximal femoral strength. In total, 36 synthetic femurs with two different proximal femoral morphologies were utilized in this study. Of them, 18 femurs with a varus NSA of 120° and 18 femurs with a valgus NSA of 135° were each implanted with a mid-head resection prosthesis. Femurs within the two different femoral morphology groups were divided into three equal coronal implant alignment groups: 10° valgus, 10° varus or neutral alignment. Prepared femurs were tested for stiffness and to failure in axial compression. There was no significant difference in stiffness nor failure load between femurs implanted with valgus-, varus- or neutrally aligned implants in femurs with a NSA of 120° (p = 0.396, p = 0.111, respectively). Femurs implanted in valgus orientation were significantly stiffer and failed at significantly higher loads than those implanted in varus alignment in femurs with a NSA of 135° (p = 0.001, p = 0.007, respectively). A mid-head resection short-stem hip arthroplasty seems less sensitive to clinically relevant variations of coronal implant alignment and may be more forgiving upon implantation in some femoral morphologies, however, a relative valgus component alignment is recommended. PMID:25515228

  18. Fabrication of low-cost, cementless femoral stem 316L stainless steel using investment casting technique.

    PubMed

    Baharuddin, Mohd Yusof; Salleh, Sh-Hussain; Suhasril, Andril Arafat; Zulkifly, Ahmad Hafiz; Lee, Muhammad Hisyam; Omar, Mohd Afian; Abd Kader, Ab Saman; Mohd Noor, Alias; A Harris, Arief Ruhullah; Abdul Majid, Norazman

    2014-07-01

    Total hip arthroplasty is a flourishing orthopedic surgery, generating billions of dollars of revenue. The cost associated with the fabrication of implants has been increasing year by year, and this phenomenon has burdened the patient with extra charges. Consequently, this study will focus on designing an accurate implant via implementing the reverse engineering of three-dimensional morphological study based on a particular population. By using finite element analysis, this study will assist to predict the outcome and could become a useful tool for preclinical testing of newly designed implants. A prototype is then fabricated using 316L stainless steel by applying investment casting techniques that reduce manufacturing cost without jeopardizing implant quality. The finite element analysis showed that the maximum von Mises stress was 66.88 MPa proximally with a safety factor of 2.39 against endosteal fracture, and micromotion was 4.73 μm, which promotes osseointegration. This method offers a fabrication process of cementless femoral stems with lower cost, subsequently helping patients, particularly those from nondeveloped countries. PMID:24404766

  19. Long-term Outcome of Polished Stems in Total Hip Arthroplasty

    PubMed Central

    Park, Jin-Young; Han, Hong-Joon; Baik, Seok-Jong

    2015-01-01

    Purpose The purpose of this study was to evaluate the clinical outcomes and radiologic findings of primary total hip arthroplasty (THA) using cemented polished femoral stems. Materials and Methods We retrospectively reviewed 91 hips (91 patients) that had undergone primary THA with cemented polished femoral stems who were followed for at least 10 years. The mean age at surgery was 57 years (47-75 years). Mean follow up period was 12.8 years (10.1-14.0 years). Harris Hip Score (HHS) was used for clinical evaluation. Radiologic evaluation was focused on cementing technique including subsidence within the cement mantle, radiolucent lines at the cement-bone or cement-stem interface, cortical hypertrophy, and calcar resorption. Results The average HHS was 55.2 points before the surgery that improved to an average of 93.2 points at the final follow-up. According to Barrack classification, there were 50, 32, and 9 cases in A, B, and C grades, respectively. Subsidence of femoral stem was less than 2 mm except in one patient. There were no progressing radiolucent line or loosening of the femoral stem. Conclusion In this study, THA using cemented polished femoral stems was found to have favorable outcomes in long term follow-up.

  20. Minimum 10-year Survival of Kerboull Cemented Stems According to Surface Finish

    PubMed Central

    Baqué, François; Lefevre, Nicolas; Kerboull, Marcel

    2008-01-01

    The optimal surface finish for a cemented THA stem is still debated. We hypothesized surface finish would influence survival of Kerboull cemented hip arthroplasties and a matte finish would have lower survival. We reviewed survival of 433 total hip arthroplasties in 395 patients: 284 consecutive patients (310 hips) were enrolled in a prospective, randomized study of polished (165 hips) or matte finish stems (145 hips) and compared to a historical series of satin stems (123 hips) in 111 patients. The satin and matte finish implants had similar geometry but the polished was quadrangular rather than oval. Finish roughnesses were: polished (radius, 0.04 μm), satin (radius, 0.9 μm), and matte (radius, 1.7 μm). The mean age of the patients at the time of the index arthroplasty was 63.6 years. The survival rate at 13 years, using radiographic loosening as the end point, was 97.3% ± 2.6% for polished stems, 97.1% ± 2.1% for satin stems, and 78.9% ± 5.8% for matte stems. The data suggest survival of Kerboull stems was higher with a polished or satin surface finish than with a matte finish. Level of Evidence: Level II, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18196414

  1. 21 CFR 888.3390 - Hip joint femoral (hemi-hip) metal/polymer cemented or uncemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... includes prostheses that have a femoral component made of alloys, such as cobalt-chromium-molybdenum, and a snap-fit acetabular component made of an alloy, such as cobalt-chromium-molybdenum, and...

  2. 21 CFR 888.3390 - Hip joint femoral (hemi-hip) metal/polymer cemented or uncemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... includes prostheses that have a femoral component made of alloys, such as cobalt-chromium-molybdenum, and a snap-fit acetabular component made of an alloy, such as cobalt-chromium-molybdenum, and...

  3. 21 CFR 888.3390 - Hip joint femoral (hemi-hip) metal/polymer cemented or uncemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... includes prostheses that have a femoral component made of alloys, such as cobalt-chromium-molybdenum, and a snap-fit acetabular component made of an alloy, such as cobalt-chromium-molybdenum, and...

  4. 21 CFR 888.3390 - Hip joint femoral (hemi-hip) metal/polymer cemented or uncemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... includes prostheses that have a femoral component made of alloys, such as cobalt-chromium-molybdenum, and a snap-fit acetabular component made of an alloy, such as cobalt-chromium-molybdenum, and...

  5. 21 CFR 888.3390 - Hip joint femoral (hemi-hip) metal/polymer cemented or uncemented prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... includes prostheses that have a femoral component made of alloys, such as cobalt-chromium-molybdenum, and a snap-fit acetabular component made of an alloy, such as cobalt-chromium-molybdenum, and...

  6. Cement mantle stress under retroversion torque at heel-strike.

    PubMed

    Afsharpoya, B; Barton, D C; Fisher, J; Purbach, B; Wroblewski, M; Stewart, T D

    2009-12-01

    The paper presents a theory of fixation failure and loosening in cemented total hip prostheses and proceeds to investigate this using an experimentally validated finite element model and two prosthesis types, namely the Charnley and the C-Stem. The study investigates the effects of retroversion torque occurring at heel-strike in combination with a loss of proximal cement/bone support and distal implant/cement support with a good distal cement/bone interface. A 3D finite element model was validated by comparison of femoral surface strains with those measured in an in vitro experimental simulation using an implanted Sawbone femur loaded in the heel-strike position and including a simplified representation of muscle forces. Results showed that the heel-strike position applies a high retroversion torque to the femoral stem that when combined with proximal debonding of the cement/bone interface and distal debonding of the implant/cement interface increases the strain transfer to the cement that may ultimately lead to the breakdown of the cement mantle leading on to osteolysis and loosening of the prostheses. Experimental fatigue testing of the implanted Charnley stem in a Sawbone femur produced cracks within the cement mantle that were located in positions of maximum stress supporting the finite element analysis results and theory of failure. PMID:19879794

  7. Bipolar Hemarthroplasty Using Cementless Conical Stem for Treatment of Dorr Type B and C Femoral Neck Fracture

    PubMed Central

    Kang, Jeong Hoon; Jung, Sung

    2015-01-01

    Purpose The current study aims to evaluate the clinical and the radiological outcome of bipolar hemiarthroplasty using cementless cone stem to treat osteoporotic femoral neck fracture and compare the results according to the proximal femur geometry. Materials and Methods Seventy-five hips (75 patients) that underwent bipolar hemiarthroplasty with cementless cone stem between September 2006 and December 2011 were analyzed. The minimum follow-up period was 3 years. Thirty-three hips were classified as type B and 41 as type C. The clinical outcome was assessed using Harris hip score and the walking ability score. Radiographic evaluation was performed to evaluate the stability of the prosthesis. Results At the most recent follow up, the mean Harris hip score was 86 (range, 70-92) and 65% recovered to preoperative ambulatory status. In the radiographic exam, stable stem fixation was achieved in all cases. For the complications, eight hips developed deep vein thrombosis while three hips showed heterotopic ossification. Dislocation and delayed deep infection occurred in one hip resepectively. There were no significance differences in Harris hip score and walking ability score when the type B group was compare with the type C. Conclusion Bipolar hemiarthroplasty with cementless cone stem showed an excellent early outcome both clinically and radiographically regardless of the shape of the proximal femur. We believe this prosthesis can provide early stability to the Dorr type B and C femur and is an effective treatment for treating osteoporotic femoral neck fracture. PMID:27536631

  8. Structural allograft and cemented long-stem prosthesis for complex revision hip arthroplasty: use of a trochanteric claw plate improves final hip function

    PubMed Central

    Lemoine, Camille Thevenin; Kerboull, Marcel; Courpied, Jean Pierre

    2007-01-01

    Extensive bone loss raises formidable challenges in total hip revision. The aim of this study was to evaluate the results of reconstruction using a cemented long-stem and massive structural allograft implanted in a filleted proximal femur, with and without the use of a trochanteric claw plate. Between 1988 and 2001, 44 revisions were performed in 42 patients. After a transtrochanteric approach, the femur was cut longitudinally. A long, cemented Charnley-type prosthesis was used, and flaps of the residual femur were folded around the allograft. The greater trochanter was reinserted with wires in all revisions, and with both wires and a claw plate in 20 revisions. Mean follow-up was 7.15 years (range: 3–16); seven patients, died and four were lost to follow-up. The follow-up exceeded five years in 34 patients. The major complication was nonunion of the greater trochanter, which occurred in 25 cases. Six dislocations, one recurrence of infection, two mechanical loosening, and two fractures below the stem were also recorded. The use of a trochanteric claw plate significantly improved final hip stability, even in patients with nonunion. Femoral reconstruction with a massive structural allograft is reliable and long-lived, and serious complications and long-term resorption are uncommon. The use of a trochanteric claw plate significantly improves final hip stability. Level of evidence: Therapeutic study, level III (retrospective comparative study). PMID:18008098

  9. Improve the performance of coated cemented hip stem through the advanced composite materials.

    PubMed

    Hedia, H S; Fouda, N

    2015-01-01

    Design of hip joint implant using functionally graded material (FGM) (advanced composite material) has been used before through few researches. It gives great results regarding the stress distribution along the implant and bone interfaces. However, coating of orthopaedic implants has been widely investigated through many researches. The effect of using advanced composite stem material, which mean by functionally graded stem material, in the total hip replacement coated with the most common coated materials has not been studied yet. Therefore, this study investigates the effect of utilizing these two concepts together; FGM and coating, in designing new stem material. It is concluded that the optimal FGM cemented stem is consisting from titanium at the upper stem layers graded to collagen at a lower stem layers. This optimal graded stem coated with hydroxyapatite found to reduce stress shielding by 57% compared to homogenous titanium stem coated with hydroxyapatite. However, the optimal functionally graded stem coated with collagen reduced the stress shielding by 51% compared to homogenous titanium stem coated with collagen. PMID:26407117

  10. Comparison of Perioperative Blood Loss in Primary Non-cemented Total Hip Arthroplasty for Rapidly Destructive Coxarthrosis and Osteonecrosis of the Femoral Head

    PubMed Central

    Song, Joo-Hyoun; Han, Suk Ku; Lee, Kyung-Hoon; Lee, Jae-Min

    2015-01-01

    Purpose The purpose of this study is to compare the perioperative blood loss in primary non-cemented total hip arthroplasty (THA) performed for rapidly destructive coxarthrosis (RDC) with the perioperative blood loss in primary non-cemented THA for typical osteonecrosis of the femoral head (ONFH). Materials and Methods From January 2000 to December 2013, 19 patients were diagnosed with RDC (group 1) and 40 patients were diagnosed typical Ficat stage IV ONFH (group 2), comparison of perioperative blood loss between group 1 and group 2 in primary noncemented THA was done. Patients with preoperative usage of steroid or anticoagulants medication and with hemodynamic abnormal blood test results were excluded. The blood loss was measured up to the fifth post operation day and calculated with formula proposed by Mercuriali, Inghilleri and Nadler. Results Non-compensated blood loss calculated in milliliters of red blood cells was 362 mL (standard deviation [SD], 187; range, 77-675) in group 1 and 180 mL (SD, 145; range, 53-519) in group 2. Compensated blood loss was 630 mL (SD, 180; range, 380-760) in group 1 and 503 mL (SD, 260; range, 190-1, 505) in group 2. The total blood loss after primary non-cemented THA is greater when surgery is performed for RDC than for ONFH, with the volume of 992 mL (SD, 300; range, 457-1, 434) in group 1 and 683 mL (SD, 360; range, 226-1, 975) in group 2 respectively. Conclusion Total perioperative blood loss was significantly greater in RDC than in ONFH in primary non-cemented THA. PMID:27536617

  11. Impact of intraprosthetic drilling on the strength of the femoral stem in periprosthetic fractures: A finite element investigation.

    PubMed

    Brand, Stephan; Bauer, Michael; Petri, Maximilian; Schrader, Julian; Maier, Hans J; Krettek, Christian; Hassel, Thomas

    2016-07-01

    Treatment of periprosthetic femur fractures after total hip arthroplasty remains a major challenge in orthopedic surgery. Recently, a novel surgical technique using intraprosthetic screw fixation has been suggested. The purpose of this study was to evaluate the influence of drilling the femoral hip stem on integrity and strength of the implant. The hypothesis was that intraprosthetic drilling and screw fixation would not cause the load limit of the prosthesis to be exceeded and that deformation would remain within the elastic limit. A sawbone model with a conventional straight hip stem was used and a Vancouver C periprosthetic fracture was created. The fracture was fixed with a nine-hole less invasive stabilization system plate with two screws drilled and inserted through the femoral hip stem. Three different finite element models were created using ANSYS software. The models increased in complexity including joint forces and stress risers from three different dimensions. A variation of drilling positions was analyzed. Due to the complexity of the physiological conditions in the human femur, the most complex finite element model provided the most realistic results. Overall, significant changes in the stresses to the prosthesis caused by the drilling procedure were observed. While the stresses at the site of the bore hole decreased, the load increased in the surrounding stem material. This effect is more pronounced and further the holes were apart, and it was found that increasing the number of holes could counteract this. The maximum load was still found to be in the area of the prosthesis neck. No stresses above the load limit of titanium alloy were detected. All deformations of the prosthesis stem remained in the elastic range. These results may indicate a potential role for intraprosthetic screw fixation in the future treatment of periprosthetic femur fractures. PMID:27272200

  12. Revision of hemiarthroplasty to total hip arthroplasty using the cement-in-cement technique.

    PubMed

    Mounsey, E J; Williams, D H; Howell, J R; Hubble, M J

    2015-12-01

    Revision of a cemented hemiarthroplasty of the hip may be a hazardous procedure with high rates of intra-operative complications. Removing well-fixed cement is time consuming and risks damaging already weak bone or perforating the femoral shaft. The cement-in-cement method avoids removal of intact cement and has shown good results when used for revision total hip arthroplasty (THA). The use of this technique for the revision of a hemiarthroplasty to THA has not been previously reported. A total of 28 consecutive hemiarthroplasties (in 28 patients) were revised to a THA using an Exeter stem and the cement-in-cement technique. There were four men and 24 women; their mean age was 80 years (35 to 93). Clinical and radiographic data, as well as operative notes, were collected prospectively and no patient was lost to follow-up. Four patients died within two years of surgery. The mean follow up of the remainder was 70 months (25 to 124). Intra-operatively there was one proximal perforation, one crack of the femoral calcar and one acetabular fracture. No femoral components have required subsequent revision for aseptic loosening or are radiologically loose. Four patients with late complications (14%) have since undergone surgery (two for a peri-prosthetic fracture, and one each for deep infection and recurrent dislocation) resulting in an overall major rate of complication of 35.7%. The cement-in-cement technique provides reliable femoral fixation in this elderly population and may reduce operating time and rates of complication. PMID:26637675

  13. Effects of Prosthesis Stem Tapers on Stress Distribution of Cemented Hip Arthroplasty

    NASA Astrophysics Data System (ADS)

    Abdullah, Abdul Halim; Nor, Mohd Asri Mohd; Saman, Alias Mohd; Tamin, Mohd Nasir; Kadir, Mohammed Rafiq Abdul

    2010-10-01

    Aseptic loosening effects are critical issues in encouraging long term stability of cemented hip arthroplasty. Stress shielding is believed to be an important factor that contributes to the aseptic loosening problems. The numerous changes in the prosthesis stem design are intended to minimize the stress shielding and aseptic loosening problems and to improve the long term performance of the implants. In this study, the stress distribution in cemented hip arthroplasty is established using finite element method. The taper of the prosthesis is designed to be 3° at anterior/posterior, 3° at medial/lateral and 10° from wide lateral to narrow medial. Major muscle loads and contact forces are simulated for walking (toe-off phase) and stair climbing load cases. Effects of prosthesis stem tapers on the resulting stress distribution are investigated. Results show that compressive stress dominates in the medial plane while tensile stress in the lateral plane of the femur. The corresponding stress levels of intact femur for walking and stair-climbing load cases are 22 and 29 MPa, respectively. The magnitude of Tresca stress for the THA femur in stair-climbing load case remains higher in the region of 85 MPa while the walking load case induces around 40 MPa. The stress range in the straight and single taper stem prosthesis is lower than 260 MPa, while localized Tresca stress is in the order of the yield strength of Ti-6Al-4V alloy for double and triple taper stem design.

  14. Effects of Prosthesis Stem Tapers on Stress Distribution of Cemented Hip Arthroplasty

    SciTech Connect

    Abdullah, Abdul Halim; Nor, Mohd Asri Mohd; Saman, Alias Mohd; Tamin, Mohd Nasir; Kadir, Mohammed Rafiq Abdul

    2010-10-15

    Aseptic loosening effects are critical issues in encouraging long term stability of cemented hip arthroplasty. Stress shielding is believed to be an important factor that contributes to the aseptic loosening problems. The numerous changes in the prosthesis stem design are intended to minimize the stress shielding and aseptic loosening problems and to improve the long term performance of the implants. In this study, the stress distribution in cemented hip arthroplasty is established using finite element method. The taper of the prosthesis is designed to be 3 deg. at anterior/posterior, 3 deg. at medial/lateral and 10 deg. from wide lateral to narrow medial. Major muscle loads and contact forces are simulated for walking (toe-off phase) and stair climbing load cases. Effects of prosthesis stem tapers on the resulting stress distribution are investigated. Results show that compressive stress dominates in the medial plane while tensile stress in the lateral plane of the femur. The corresponding stress levels of intact femur for walking and stair-climbing load cases are 22 and 29 MPa, respectively. The magnitude of Tresca stress for the THA femur in stair-climbing load case remains higher in the region of 85 MPa while the walking load case induces around 40 MPa. The stress range in the straight and single taper stem prosthesis is lower than 260 MPa, while localized Tresca stress is in the order of the yield strength of Ti-6Al-4V alloy for double and triple taper stem design.

  15. Adaptive Bone Remodeling of the Femoral Bone After Tumor Resection Arthroplasty With an Uncemented Proximally Hydroxyapatite-Coated Stem.

    PubMed

    Andersen, Mikkel R; Petersen, Michael M

    2016-01-01

    Loss of bone stock and stress shielding is a significant challenge in limb salvage surgery. This study investigates the adaptive bone remodeling of the femoral bone after implantation of a tumor prosthesis with an uncemented press fit stem. We performed a prospective 1 yr follow-up of 6 patients (mean age: 55 (26-78) yr, female/male=3/3) who underwent bone tumor resection surgery of the proximal femur (n=3) or distal femur (n=3). Reconstruction was done using a Global Modular Replacement System (Stryker® Orthopaedics, Mahwah, NJ) tumor prosthesis, and all patients received a straight-fluted 125-mm uncemented press-fit titanium alloy stem with hydroxyapatite coating of the proximal part of the stem. Measurements of bone mineral density (BMD; g/cm2) were done postoperatively and after 3, 6, and 12 mo in the part of the femur bone containing the Global Modular Replacement System stem using dual-energy X-ray absorptiometry. BMD was measured in 3 regions of interest (ROIs) in the femur bone. Nonparametric analysis of variance (Friedman test) for evaluation of changes in BMD over time. BMD decreased in all 3 ROIs with time. In ROI 1 (p=0.01), BMD decreased by 10% after 3 mo and ended with a total decrease of 14% after 1 yr. In ROI 2 (p=0.006), BMD was decreased by 6% after 3 and 6 mo; after 1 yr of follow-up, BMD was 9% below the postoperative value. In ROI 3 (p=0.009), BMD decreased by 6% after 3 and 6 mo; after 1 yr of follow-up, BMD was 8% below the postoperative value. A bone loss of 8%-9% during the first postoperative year was seen along the femoral stem, but in the bone containing the hydroxyapatite-coated part of the stem, the decrease in BMD was 14%, thus indicating that stress shielding of this part of the bone may play a role for the adaptive bone remodeling. PMID:25843447

  16. In vivo testing of porous Ti-25Nb alloy serving as a femoral stem prosthesis in a rabbit model

    PubMed Central

    Weng, Xiaojun; Yang, Hailin; Xu, Jian; Li, Xiaosheng; Liao, Qiande; Wang, Jing

    2016-01-01

    The aim of the present study was to observe the performance of Ti-25Nb alloys with various porosities as femoral stem prostheses in a rabbit model, thus providing basic experimental evidence for the development of porous prostheses. The porous Ti-25Nb alloy prostheses were designed according to the morphology of the medullary cavity. These prostheses were placed into the femoral medullary cavities in 36 New Zealand white rabbits. Postoperative X-ray films, scanning electron microscopy (SEM) of the implant interface, energy-dispersive spectroscopy (EDS) analysis of the implant surface, pulling-out test and general observations were conducted. The specimens showed good biocompatibility; there was no obvious bone absorption in porous Ti-25Nb specimens with different porosities at different time points observed using X-ray films. Under SEM examination, calcium deposits were observed inside the pores and in the interface between bone and prostheses. The EDS analysis demonstrated that calcium deposits were present on the surface of the prostheses at the eight-week point postoperatively. The pulling-out test showed good bonding strength between bone and implant; after pulling out, the surface and inside the pores of the prostheses all presented bone mass. Porous Ti-25Nb alloy implants presents good biocompatibility as well as providing a biological fixation between the bone and implant. A porosity of 70% is more advantageous to the newborn bone ingrowth, combined with achieving a more solid bone-implant interface. PMID:27602063

  17. Preclinical Study of Cell Therapy for Osteonecrosis of the Femoral Head with Allogenic Peripheral Blood-Derived Mesenchymal Stem Cells

    PubMed Central

    Fu, Qiang; Tang, Ning-Ning; Zhang, Qian; Liu, Yi; Peng, Jia-Chen; Fang, Ning; Yu, Li-Mei; Liu, Jin-Wei

    2016-01-01

    Purpose To explore the value of transplanting peripheral blood-derived mesenchymal stem cells from allogenic rabbits (rPBMSCs) to treat osteonecrosis of the femoral head (ONFH). Materials and Methods rPBMSCs were separated/cultured from peripheral blood after granulocyte colony-stimulating factor mobilization. Afterwards, mobilized rPBMSCs from a second passage labeled with PKH26 were transplanted into rabbit ONFH models, which were established by liquid nitrogen freezing, to observe the effect of rPBMSCs on ONFH repair. Then, the mRNA expressions of BMP-2 and PPAR-γ in the femoral head were assessed by RT-PCR. Results After mobilization, the cultured rPBMSCs expressed mesenchymal markers of CD90, CD44, CD29, and CD105, but failed to express CD45, CD14, and CD34. The colony forming efficiency of mobilized rPBMSCs ranged from 2.8 to 10.8 per million peripheral mononuclear cells. After local transplantation, survival of the engrafted cells reached at least 8 weeks. Therein, BMP-2 was up-regulated, while PPAR-γ mRNA was down-regulated. Additionally, bone density and bone trabeculae tended to increase gradually. Conclusion We confirmed that local transplantation of rPBMSCs benefits ONFH treatment and that the beneficial effects are related to the up-regulation of BMP-2 expression and the down-regulation of PPAR-γ expression. PMID:27189298

  18. Second-Generation Versus First-Generation Cementless Tapered Wedge Femoral Stems.

    PubMed

    Pierce, Todd P; Jauregui, Julio J; Kapadia, Bhaveen H; Elmallah, Randa K; Cherian, Jeffrey J; Harwin, Steven F; Mont, Michael A

    2015-09-01

    Clinical outcomes of a new second-generation proximally coated, tapered wedge cementless stem were compared with those of its predecessor regarding (1) all-cause implant survivorship; (2) objective and subjective outcomes; (3) complications; and (4) radiographic features. Patients who underwent a primary total hip arthroplasty with the second-generation stem (68 hips) were compared with those who received the first-generation stem (136 hips) at a mean follow-up of 3.5 years. Although the first-generation stem was designed in the traditional manner, the second-generation stem was shortened to accommodate all surgical approaches and designed using a computed tomography scan-based database to enhance fit. The second-generation stem had survivorship, functional, and subjective outcomes similar to those of the first-generation stem. PMID:26375526

  19. The Fate and Distribution of Autologous Bone Marrow Mesenchymal Stem Cells with Intra-Arterial Infusion in Osteonecrosis of the Femoral Head in Dogs

    PubMed Central

    Jin, Hongting; Xu, Taotao; Chen, Qiqing; Wu, Chengliang; Wang, Pinger; Mao, Qiang; Zhang, Shanxing; Shen, Jiayi; Tong, Peijian

    2016-01-01

    This study aimed to investigate if autologous bone marrow mesenchymal stem cells (MSCs) could treat osteonecrosis of the femoral head (ONFH) and what the fate and distribution of the cells are in dogs. Twelve Beagle dogs were randomly divided into two groups: MSCs group and SHAM operated group. After three weeks, dogs in MSCs group and SHAM operated group were intra-arterially injected with autologous MSCs and 0.9% normal saline, respectively. Eight weeks after treatment, the necrotic volume of the femoral heads was significantly reduced in MSCs group. Moreover, the trabecular bone volume was increased and the empty lacunae rate was decreased in MSCs group. In addition, the BrdU-positive MSCs were unevenly distributed in femoral heads and various vital organs. But no obvious abnormalities were observed. Furthermore, most of BrdU-positive MSCs in necrotic region expressed osteocalcin in MSCs group and a few expressed peroxisome proliferator-activated receptor-γ (PPAR-γ). Taken together, these data indicated that intra-arterially infused MSCs could migrate into the necrotic field of femoral heads and differentiate into osteoblasts, thus improving the necrosis of femoral heads. It suggests that intra-arterial infusion of autologous MSCs might be a feasible and relatively safe method for the treatment of femoral head necrosis. PMID:26779265

  20. 21 CFR 888.3380 - Hip joint femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... device includes prostheses that consist of a metallic stem made of alloys, such as cobalt-chromium... is covered by a metallic alloy, such as cobalt-chromium-molybdenum. The trunnion bearing allows...

  1. 21 CFR 888.3380 - Hip joint femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... device includes prostheses that consist of a metallic stem made of alloys, such as cobalt-chromium... is covered by a metallic alloy, such as cobalt-chromium-molybdenum. The trunnion bearing allows...

  2. 21 CFR 888.3380 - Hip joint femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... device includes prostheses that consist of a metallic stem made of alloys, such as cobalt-chromium... is covered by a metallic alloy, such as cobalt-chromium-molybdenum. The trunnion bearing allows...

  3. 21 CFR 888.3380 - Hip joint femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... device includes prostheses that consist of a metallic stem made of alloys, such as cobalt-chromium... is covered by a metallic alloy, such as cobalt-chromium-molybdenum. The trunnion bearing allows...

  4. 21 CFR 888.3380 - Hip joint femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... device includes prostheses that consist of a metallic stem made of alloys, such as cobalt-chromium... is covered by a metallic alloy, such as cobalt-chromium-molybdenum. The trunnion bearing allows...

  5. Examination of rotational fixation of the femoral component in total hip arthroplasty. A mechanical study of micromovement and acoustic emission.

    PubMed

    Sugiyama, H; Whiteside, L A; Kaiser, A D

    1989-12-01

    Rotational loosening has recently emerged as an important cause of failure of the femoral component of total hip arthroplasties. This study was designed to investigate the role played by torsional loads in loosening of cementless femoral components and to evaluate three cementing techniques involving a combination of canal irrigation, manual insertion, and vacuum mixing combined with pressure injection of the cement for their ability to improve rotational fixation. Rotational micromotion and subsidence were measured in 24 preserved human anatomic specimen femora. Acoustic emission (AE) technique was applied as a non-destructive method for evaluating material failure during loading. From the micromovement data, torque to 50 mu subsidence and torque to failure were surprisingly low with cementless fixation and with poor cement technique but were markedly improved with pulsed irrigation. Further improvement was achieved by pressure injection and vacuum mixing of the cement. However, AE was detected even in the most carefully performed cement specimens under torsional-loading conditions commonly occurring in daily activities. These signs of microfailure of the cement mantle at relatively low torsional loads suggest that the mode of failure of deeply penetrated cement is by microfracture of the cement mantle. The poor performance suggests that cementless fixation of intramedullary stems provides unsatisfactory fixation against torsional loading. There is need for major improvements in fixation mechanisms and techniques. The signs of failure of the cement mantle at normally occurring torsional loads suggest that even the best cement technique is prone to failure in torsion when exposed to normal daily use. PMID:2582663

  6. A Review of Periprosthetic Femoral Fractures Associated With Total Hip Arthroplasty

    PubMed Central

    Marsland, Daniel; Mears, Simon C.

    2012-01-01

    Periprosthetic fractures of the femur in association with total hip arthroplasty are increasingly common and often difficult to treat. Patients with periprosthetic fractures are typically elderly and frail and have osteoporosis. No clear consensus exists regarding the optimal management strategy because there is limited high-quality research. The Vancouver classification facilitates treatment decisions. In the presence of a stable prosthesis (type-B1 and -C fractures), most authors recommend surgical stabilization of the fracture with plates, strut grafts, or a combination thereof. In up to 20% of apparent Vancouver type-B1 fractures, the femoral stem is loose, which may explain the high failure rates associated with open reduction and internal fixation. Some authors recommend routine opening and dislocation of the hip to perform an intraoperative stem stability test to rule out a loose component. Advances in plating techniques and technology are improving the outcomes for these fractures. For fractures around a loose femoral prosthesis (types B2 and 3), revision using an extensively porous-coated uncemented long stem, with or without additional fracture fixation, appears to offer the most reliable outcome. Cement-in-cement revision using a long-stem prosthesis is feasible in elderly patients with a well-fixed cement mantle. It is essential to treat the osteoporosis to help fracture healing and to prevent further fractures. We provide an overview of the causes, classification, and management of periprosthetic femoral fractures around a total hip arthroplasty based on the current best available evidence. PMID:23569704

  7. Oxinium modular femoral heads do not reduce polyethylene wear in cemented total hip arthroplasty at five years: a randomised trial of 120 hips using radiostereometric analysis.

    PubMed

    Jonsson, B A; Kadar, T; Havelin, L I; Haugan, K; Espehaug, B; Indrekvam, K; Furnes, O; Hallan, G

    2015-11-01

    We report the five-year outcome of a randomised controlled trial which used radiostereometric analysis (RSA) to assess the influence of surface oxidised zirconium (OxZr, Oxinium) on polyethylene wear in vivo. A total of 120 patients, 85 women and 35 men with a mean age of 70 years (59 to 80) who were scheduled for primary cemented total hip arthroplasty were randomly allocated to four study groups. Patients were blinded to their group assignment and received either a conventional polyethylene (CPE) or a highly cross-linked (HXL) acetabular component of identical design. On the femoral side patients received a 28 mm head made of either cobalt-chromium (CoCr) or OxZr. The proximal head penetration (wear) was measured with repeated RSA examinations over five years. Clinical outcome was measured using the Harris hip score. There was no difference in polyethylene wear between the two head materials when used with either of the two types of acetabular component (p = 0.3 to 0.6). When comparing the two types of polyethylene there was a significant difference in favour of HXLPE, regardless of the head material used (p < 0.001). In conclusion, we found no advantage of OxZr over CoCr in terms of polyethylene wear after five years of follow-up. Our findings do not support laboratory results which have shown a reduced rate of wear with OxZr. They do however add to the evidence on the better resistance to wear of HXLPE over CPE. PMID:26530646

  8. The Healing Effect of Adipose-Derived Mesenchymal Stem Cells in Full-thickness Femoral Articular Cartilage Defects of Rabbit

    PubMed Central

    Mehrabani, D.; Babazadeh, M.; Tanideh, N.; Zare, S.; Hoseinzadeh, S.; Torabinejad, S.; Koohi-Hosseinabadi, O.

    2015-01-01

    Background: Articular cartilage defect can lead to degradation of subchondral bone and osteoarthritis (OA). Objective: To determine the healing effect of transplantation of adipose-derived mesenchymal stem cells (Ad-MSCs) in full-thickness femoral articular cartilage defects in rabbit. Methods: 12 rabbits were equally divided into cell-treated and control groups. In cell-treated group, 2×106 cells of third passage suspended in 1 mL of DMEM was injected into articular defect. The control group just received 1 mL of DMEM. Dulbecco’s modified Eagles medium (DMEM) supplemented with 10% fetal bovine serum (FBS), 1% penicillin and streptomycin and 2 mM L-glutamine were used for cell culture. To induce cartilage defect, 4 mm articular cartilage full-thickness defect was created in the knee. For histological evaluation in each group (H&E, safranin-O and toluidine blue), 3 rabbits were sacrificed 4 weeks and 3 animals, 8 weeks after cell transplantation. Results: In cell therapy group post-transplantation, no abnormal gross findings were noticed. Neo-formed tissues in cell-treated groups were translucent with a smooth and intact surface and less irregularity. In cell-treated group after 8 weeks post-transplantation, the overall healing score of experimental knees were superior when compared to other groups. Conclusion: We showed that Ad-MSCs, as an available and non-invasive produced source of cells, could be safely administered in knee osteochondral defects. PMID:26576262

  9. Skeletal muscle perfusion and stem cell delivery in muscle disorders using intra-femoral artery canulation in mice.

    PubMed

    Matthias, Nadine; Hunt, Samuel D; Wu, Jianbo; Darabi, Radbod

    2015-11-15

    Muscular dystrophies are among major inherited muscle disorders characterized by progressive muscle damage and fibrosis with no definitive cure. Recently, gene or cell based therapies have been developed to restore the missing gene expression or replace the damaged tissues. In order to test the efficiency of these therapies in mice models of muscular dystrophies, the arterial route of delivery is very advantageous as it provides uniform muscle exposure to the therapeutic agents or cells. Although there are few reports of arterial delivery of the therapeutic agents or cells in mice, there is no in-depth description and evaluation of its efficacy in perfusion of downstream muscles. This study is aimed to develop a practical method for intra-femoral artery perfusion in mice and to evaluate perfusion efficiency using near-infrared-fluorescence (NIRF) imaging as well as histology following stem cell delivery. Our results provide a practical guide to perform this delicate method in mice. By using a sensitive fluorescent dye, different muscle groups of the hindlimb have been evaluated for proper perfusion. As the final step, we have validated the efficiency of arterial cell delivery into muscles using human iPS-derived myogenic cells in an immunodeficient mouse model for Duchenne muscular dystrophy (NSG-mdx(4cv)). PMID:26341268

  10. Determining material loss from the femoral stem trunnion in hip arthroplasty using a coordinate measuring machine.

    PubMed

    Bone, Martin C; Sidaginamale, Raghavendra P; Lord, James K; Scholes, Susan C; Joyce, Thomas J; Nargol, Anthony V F; Langton, David J

    2015-01-01

    In contrast to the articulating and taper surfaces of failed total hip replacements, volumetric wear analysis of trunnions is not routinely performed. Metal wear particles from the trunnion may contribute not only to the failures of metal-on-metal total hip replacements but also to all hip replacements utilising metal trunnions. A validation study was performed with the material removed in stages from the trunnions of an Exeter V40 stem, a Corail stem and an Accolade stem to simulate different magnitudes of wear. The material loss from the trunnions was measured both volumetrically with a coordinate measuring machine and gravimetrically with a high-precision balance. A cohort of 28 ex vivo trunnions was also measured using the coordinate measuring machine. The maximum error between the two methods was found to be 0.13 mm(3). This result was comparable with the coordinate measuring machine method for the taper surface (0.2 mm(3)). The ex vivo trunnions had a median wear volume of 0.14mm(3) (range: 0.04-0.28 mm(3)). This is the first study to determine the accuracy of volumetric wear measurements of trunnions by comparing against gravimetric measurements. Volumetric wear analysis of trunnions may provide additional insights into failures of modular total hip prostheses and will be performed routinely at our centre. PMID:25655956

  11. Vascular endothelial growth factor/bone morphogenetic protein-2 bone marrow combined modification of the mesenchymal stem cells to repair the avascular necrosis of the femoral head

    PubMed Central

    Ma, Xiao-Wei; Cui, Da-Ping; Zhao, De-Wei

    2015-01-01

    Vascular endothelial cell growth factor (VEGF) combined with bone morphogenetic protein (BMP) was used to repair avascular necrosis of the femoral head, which can maintain the osteogenic phenotype of seed cells, and effectively secrete VEGF and BMP-2, and effectively promote blood vessel regeneration and contribute to formation and revascularization of tissue engineered bone tissues. To observe the therapeutic effect on the treatment of avascular necrosis of the femoral head by using bone marrow mesenchymal stem cells (BMSCs) modified by VEGF-165 and BMP-2 in vitro. The models were avascular necrosis of femoral head of rabbits on right leg. There groups were single core decompression group, core decompression + BMSCs group, core decompression + VEGF-165/BMP-2 transfect BMSCs group. Necrotic bone was cleared out under arthroscope. Arthroscopic observation demonstrated that necrotic bone was cleared out in each group, and fresh blood flowed out. Histomorphology determination showed that blood vessel number and new bone area in the repair region were significantly greater at various time points following transplantation in the core decompression + VEGF-165/BMP-2 transfect BMSCs group compared with single core decompression group and core decompression + BMSCs group (P < 0.05). These suggested that VEGF-165/BMP-2 gene transfection strengthened osteogenic effects of BMSCs, elevated number and quality of new bones and accelerated the repair of osteonecrosis of the femoral head. PMID:26629044

  12. Methotrexate released in vitro from bone cement inhibits human stem cell proliferation in S/G2 phase

    PubMed Central

    Prochazka, Egon; Soukup, Tomas; Hroch, Milos; Fuksa, Leos; Brcakova, Eva; Cermanova, Jolana; Kolouchova, Gabriela; Urban, Karel; Mokry, Jaroslav

    2009-01-01

    Methotrexate (MTX) released from bone cement showed a useful local effect in animal models of bone tumours. However, local toxic reactions such as impaired wound healing were observed in areas surrounding the MTX-loaded implant. Therefore, we hypothesised that MTX released from bone cement would have harmful effects on human mesenchymal stem cells (MSC)—one of the basic components of bone marrow and tissue reparatory processes. Moreover, elution of MTX was calculated from implants prepared either with liquid or powdered MTX. During the 28-day incubation, the cement compounded with liquid MTX showed the highest elution rate of the drug. MTX released from pellets produced a significant decrease in proliferation of MSC as a consequence of a blockade of their cell cycle in the S/G2 phase. These findings indicate impairment of stem cell function in marginal areas surrounding the MTX-loaded cement and may help to explain problems with regeneration of tissues in these locations. PMID:19205701

  13. Effects of Tricalcium Silicate Cements on Osteogenic Differentiation of Human Bone Marrow-Derived Mesenchymal Stem Cells In Vitro

    PubMed Central

    Eid, Ashraf A.; Hussein, Khalid A.; Niu, Li-na; Li, Guo-hua; Watanabe, Ikuya; Al-Shabrawey, Mohamed; Pashley, David H.; Tay, Franklin R.

    2014-01-01

    Tricalcium silicate cements have been successfully employed in the biomedical field as bioactive bone and dentin substitutes, with widely acclaimed osteoactive properties. This research analyzed the effects of different tricalcium silicate cement formulations on the temporal osteoactivity profile of human bone marrow-derived mesenchymal stem cells (hMW-MSCs). These cells were exposed to 4 commercially-available tricalcium silicate cement formulations in osteogenic differentiation medium. After 1, 3, 7 and 10 days, quantitative real time-polymerase chain reaction and Western blotting were performed to detect the expression of target osteogenic markers ALP, RUNX2, OSX, OPN, MSX2, and OCN. After 3, 7, 14 and 21 days, alkaline phosphatase assay was performed to detect changes in intracellular enzyme level. Alizarin Red S assay was performed after 28 days to detect extracellular matrix mineralization. In the presence of tricalcium silicate cements, target osteogenic markers were downregulated at the mRNA and protein levels at all time-points. Intracellular alkaline phosphatase enzyme levels and extracellular mineralization of the experimental groups were not significantly different from the untreated control. Quantitative polymerase chain reaction results showed increases in downregulation of RUNX2, OSX, MSX2 and OCN with increase in time of exposure to the tricalcium silicate cements, while ALP showed peak downregulation at day 7. For Western blotting, OSX, OPN, MSX2 and OCN showed increased downregulation with increased exposure time to the tested cements. Alkaline phosphatase enzyme levels generally declined after day 7. Based on these results, it is concluded that tricalcium silicate cements do not induce osteogenic differentiation of hBM-MSCs in vitro. PMID:24726977

  14. Influence of the stem fixation scenario on load transfer in a hip resurfacing arthroplasty with a biomimetic stem.

    PubMed

    Caouette, C; Bureau, M N; Vendittoli, P-A; Lavigne, M; Nuño, N

    2015-05-01

    Finite element (FE) analysis is a widely used tool for extensive preclinical testing of orthopaedic implants such as hip resurfacing femoral components, including evaluation of different stem fixation scenarios (cementation vs osseointegration, etc.). Most FE models use surface-to-surface contact elements to model the load-bearing interfaces that connect bone, cement and implant and neglect the mechanical effects of phenomena such as residual stresses from bone cement curing. The objective of the current study is to evaluate and quantify the effect of different stem fixation scenarios and related phenomena such as residual stresses from bone cement curing. Four models of a previously clinically available implant (Durom) were used to model different stem fixation scenarios of a new biomimetic stem: a cemented stem, a frictional stem, a partially and completely bonded stem, with and without residual stresses from bone cement curing. For the frictional stem, stem-bone micromotions were increased from 0% to 61% of the available surface subjected to micromotions between 10 and 40μm with the inclusion of residual stresses from bone cement curing. Bonding the stem, even partially, increased stress in the implant at the stem-head junction. Complete bonding of the stem decreased bone strain at step tip, at the cost of increased strain shielding when compared with the frictional stem and partially bonded stem. The increase of micromotions and changes in bone strain highlighted the influence of interfacial conditions on load transfer, and the need for a better modeling method, one capable of assessing the effect of phenomena such as interdigitation and residual stresses from bone cement curing. PMID:25688031

  15. Transient and residual stresses and displacements in self-curing bone cement - Part II: thermoelastic analysis of the stem fixation system.

    PubMed

    Ahmed, A M; Nair, R; Burke, D L; Miller, J

    1982-02-01

    In this second part of a two-part report, an idealized model of the stem fixation system is analyzed to determine the adverse effects of the thermal stresses and displacements of bone cement during its curing process. The Shaffer-Levitsky stress-rate strain-rate law for chemically hardening material has been used. The results show that if the cement is surrounded by cancellous bone, as opposed to cortical bone, then transient tensile circumferential stresses in the cement and similar radial stresses at the stem/cement interface are generated. The former may cause flaws and voids within the still cement, while the latter may cause gaps at the interface. PMID:7078115

  16. A laboratory investigation to assess the influence of cement augmentation of screw and plate fixation in a simulation of distal femoral fracture of osteoporotic and non-osteoporotic bone.

    PubMed

    Wähnert, D; Lange, J H; Schulze, M; Gehweiler, D; Kösters, C; Raschke, M J

    2013-10-01

    The augmentation of fixation with bone cement is increasingly being used in the treatment of severe osteoporotic fractures. We investigated the influence of bone quality on the mechanics of augmentation of plate fixation in a distal femoral fracture model (AO 33 A3 type). Eight osteoporotic and eight non-osteoporotic femoral models were randomly assigned to either an augmented or a non-augmented group. Fixation was performed using a locking compression plate. In the augmented group additionally 1 ml of bone cement was injected into the screw hole before insertion of the screw. Biomechanical testing was performed in axial sinusoidal loading. Augmentation significantly reduced the cut-out distance in the osteoporotic models by about 67% (non-augmented mean 0.30 mm (sd 0.08) vs augmented 0.13 mm (sd 0.06); p = 0.017). There was no statistical reduction in this distance following augmentation in the non-osteoporotic models (non-augmented mean 0.15 mm (sd 0.02) vs augmented 0.15 mm (sd 0.07); p = 0.915). In the osteoporotic models, augmentation significantly increased stability (p = 0.017). PMID:24078541

  17. Early cementing does not increase debond energy of grit blasted interfaces.

    PubMed

    Mann, Kenneth A; Damron, Leatha A; Race, Amos; Ayers, David C

    2004-07-01

    A fracture mechanics based approach was used to determine the debond energy or fracture toughness of the stem-cement interface for a variety of conditions. The goals of the study were to determine if early cementing of stems increased the debond energy of grit blasted stem-cement interfaces and if debond energy was dependent on mold type. Early (2 min) and late (6 min) times of cementation were considered for two different grit blasted surface finishes (16 and 60 grit, Ra=5.7 or 2.3 microm). Specimen fabrication was performed using a relatively simple, unconstrained rectangular mold and a mold that more closely simulated in vivo conditions. The rectangular mold was used with all components at room temperature whereas the in vivo simulated mold had a body that resembled the femoral canal in shape and was warmed to body temperature. Early cementing did not increase the debond energy using the in vivo simulated mold. Extensive porosity was found at the interface, and porosity had a strong negative effect on debond energy. When the simpler, rectangular mold was used, early cementing did result in higher debond energies, but few voids were found at the interface. It appears that porosity at the interface was the major factor affecting the debond energy. The results from this study do not support the concept that improved stem-cement interface strength can be obtained by application of the cement while it is in a low viscosity state. PMID:15183440

  18. The validity of a novel radiological method for measuring femoral stem version on anteroposterior radiographs of the hip after total hip arthroplasty.

    PubMed

    Weber, M; Lechler, P; von Kunow, F; Völlner, F; Keshmiri, A; Hapfelmeier, A; Grifka, J; Renkawitz, T

    2015-03-01

    Femoral stem version has a major influence on impingement and early post-operative stability after total hip arthroplasty (THA). The main objective of this study was to evaluate the validity of a novel radiological method for measuring stem version. Anteroposterior (AP) radiographs and three-dimensional CT scans were obtained for 115 patients (female/male 63/72, mean age 62.5 years (50 to 75)) who had undergone minimally invasive, cementless THA. Stem version was calculated from the AP hip radiograph by rotation-based change in the projected prosthetic neck-shaft (NSA*) angle using the mathematical formula ST = arcos [tan (NSA*) / tan (135)]. We used two independent observers who repeated the analysis after a six-week interval. Radiological measurements were compared with 3D-CT measurements by an independent, blinded external institute. We found a mean difference of 1.2° (sd 6.2) between radiological and 3D-CT measurements of stem version. The correlation between the mean radiological and 3D-CT stem torsion was r = 0.88 (p < 0.001). The intra- (intraclass correlation coefficient ≥ 0.94) and inter-observer agreement (mean concordance correlation coefficient = 0.87) for the radiological measurements were excellent. We found that femoral tilt was associated with the mean radiological measurement error (r = 0.22, p = 0.02). The projected neck-shaft angle is a reliable method for measuring stem version on AP radiographs of the hip after a THA. However, a highly standardised radiological technique is required for its precise measurement. PMID:25737512

  19. Clinical outcomes of osteonecrosis of the femoral head after autologous bone marrow stem cell implantation: a meta-analysis of seven case-control studies.

    PubMed

    Yuan, Heng-Feng; Zhang, Jing; Guo, Chang-An; Yan, Zuo-Qin

    2016-02-01

    The purpose of this study was to evaluate the clinical outcomes of osteonecrosis of the femoral head after autologous bone marrow stem cell implantation. We searched the PubMed, Embase and Web of Science databases and included all case-control trials that reported on the clinical outcomes of osteonecrosis progression, incidence of total hip arthroplasty and improvement in Harris hip scores. Overall, seven case-control trials were included. Compared with the controls, patients treated with the bone marrow stem cells implantation treatment showed improved clinical outcomes with delayed osteonecrosis progression (odds ratio = 0.17, 95% CI: 0.09 - 0.32; p <0.001), a lower total hip arthroplasty incidence (odds ratio = 0.30, 95% CI: 0.12 - 0.72; p <0.01) and increased Harris hip scores (mean difference = 4.76, 95% CI: 1.24 - 8.28; p<0.01). The heterogeneity, publication bias, and sensitivity analyses showed no statistical difference significant differences between studies. Thus, our study suggests that autologous bone marrow stem cells implantation has a good therapeutic effect on osteonecrosis of the femoral, resulting in beneficial clinical outcomes. However, trials with larger sample sizes are needed to confirm these findings. PMID:26934241

  20. Clinical outcomes of osteonecrosis of the femoral head after autologous bone marrow stem cell implantation: a meta-analysis of seven case-control studies

    PubMed Central

    Yuan, Heng-feng; Zhang, Jing; Guo, Chang-an; Yan, Zuo-qin

    2016-01-01

    The purpose of this study was to evaluate the clinical outcomes of osteonecrosis of the femoral head after autologous bone marrow stem cell implantation. We searched the PubMed, Embase and Web of Science databases and included all case-control trials that reported on the clinical outcomes of osteonecrosis progression, incidence of total hip arthroplasty and improvement in Harris hip scores. Overall, seven case-control trials were included. Compared with the controls, patients treated with the bone marrow stem cells implantation treatment showed improved clinical outcomes with delayed osteonecrosis progression (odds ratio = 0.17, 95% CI: 0.09 – 0.32; p<0.001), a lower total hip arthroplasty incidence (odds ratio = 0.30, 95% CI: 0.12 - 0.72; p<0.01) and increased Harris hip scores (mean difference = 4.76, 95% CI: 1.24 – 8.28; p<0.01). The heterogeneity, publication bias, and sensitivity analyses showed no statistical difference significant differences between studies. Thus, our study suggests that autologous bone marrow stem cells implantation has a good therapeutic effect on osteonecrosis of the femoral, resulting in beneficial clinical outcomes. However, trials with larger sample sizes are needed to confirm these findings. PMID:26934241

  1. Preparation of artificial canine femoral stem with HA-Ti ladder-type coating on plasma-sprayed pure Ti substrate and its performance evaluation

    NASA Astrophysics Data System (ADS)

    Zeng, Xianlin; Li, Jingfeng; Yang, Shuhua; Zheng, Qixin; Zou, Zhenwei

    2012-03-01

    An ideal, biological-type, artificial femoral stem prosthesis has good stability and improved bone-prosthesis bonding capacity. In the current study, pure hydroxyapatite (HA)-coated, cementless, artificial femoral stems were prepared by adopting different plasma spray powers and distances and were tested in terms of shear strength. The pure titanium (Ti) substrates, HA coatings, and composite Ti-HA ladder-type coatings prepared under vacuum and atmospheric conditions were examined to compare the shear strengths, microscopic constitutions, and structures of the coatings. The coating was fabricated and the bond strength was improved by adopting 35 kW of spray power and an 80 mm spray distance. The comparisons show that the shear strength of the Ti coating prepared under vacuum conditions was higher than that of the coating prepared under atmospheric conditions (P < 0.05). Moreover, the pressure-shear strength of the Ti + HAG + Ti + V group coating was statistically significantly different from those of the HA + Ti + V and HA + Ti + A groups (P < 0.05). The coatings were compared using scanning electron microscopy, X-ray diffraction, and infrared spectrum analysis. The composite HA-Ti ladder-type coating group, where pure Ti substrate was sprayed onto the Ti alloy under vacuum conditions, had a successive laminate structure. In addition, the intergranular bond in the HA surface layer on the gradient coating was compact and highly crystallized. Under vacuum conditions, the plasma-sprayed layer was characterized by higher tightness, moderate porosity, higher bonding strength to HA, and higher HA crystallinity. The proposed coating can be used in new, cementless, artificial femoral stems with improved bone-prosthesis bonding capacity and stability.

  2. Assessment of retention force and bone apposition in two differently coated femoral stems after 6 months of loading in a goat model

    PubMed Central

    2014-01-01

    Background Since the introduction of uncemented hip implants, there has been a search for the best surface coating to enhance bone apposition in order to improve retention. The surface coating of the different stems varies between products. The aim was to assess the retention force and bone adaption in two differently coated stems in a weight-bearing goat model. Materials and methods Hydroxyapatite (HA) and electrochemically deposited calcium phosphate (CP; Bonit®) on geometrically comparable titanium-based femoral stems were implanted into 12 (CP group) and 35 (HA group) goats. The animal model included physiological loading of the implants for 6 months. The pull-out force of the stems was measured, and bone apposition was microscopically evaluated. Results After exclusion criteria were applied, the number of available goats was 4 in the CP group and 11 in the HA group. The CP-coated stems had significantly lower retention forces compared with the HA-coated ones after 6 months (CP median 47 N, HA median 1,696 N, p = 0.003). Bone sections revealed a lower degree of bone apposition in the CP-coated stems, with more connective tissue in the bone/implant interface compared with the HA group. Conclusion In this study, HA had better bone apposition and needed greater pull-out force in loaded implants. The application of CP on the loaded titanium surface to enhance the apposition of bone is questioned. PMID:25127722

  3. Use of Cemented Spacer with a Handmade Stem to Treat Acute Periprosthetic Tibial Fracture Infection: A Case Report

    PubMed Central

    Font-Vizcarra, LluÍs; Izquierdo, Oscar; GarcÍa-NuÑo, Laura; GonzÁlez, Araceli; Diaz-Brito, VicenÇ; Castellanos, Juan

    2014-01-01

    We report an 85-year-old woman with dementia and dependent for normal life activities who was admitted due to a left periprosthetic tibial fracture. The tibial component was replaced by one with a long stem and she was discharged. Four weeks after the intervention the patient was re-admitted due to an acute prosthetic joint infection. All the components were removed and a bone-cement spacer with a handmade stem with a metal core was implanted. Radiological signs of fracture consolidation were observed after 3 months of follow-up. Due to the previous health status of the patient, it was decided to keep the spacer as a definitive treatment. After 24 months, the patient was able to sit without pain and to stand up with help using a knee brace. There were no radiological or clinical signs of infection. PMID:24551027

  4. Human tooth germ stem cell response to calcium-silicate based endodontic cements

    PubMed Central

    PAMUKÇU GÜVEN, Esra; YALVAÇ, Mehmet Emir; KAYAHAN, Mehmet Baybora; SUNAY, Hakkı; ŞAHİN, Fikrettin; BAYIRLI, Gündüz

    2013-01-01

    Objective The aim of this study was to compare the cytotoxic effects of endodontic cements on human tooth germ stem cells (hTGSCs). MTA Fillapex, a mineral trioxide aggregate (MTA)-based, salicylate resin containing root canal sealer, was compared with iRoot SP, a bioceramic sealer, and AH Plus Jet, an epoxy resin-based root canal sealer. Material and Methods To evaluate cytotoxicity, all materials were packed into Teflon rings (4 mmµ3 mm) and co-cultured with hTGSCs with the aid of 24-well Transwell permeable supports, which had a pore size of 0.4 µm. Coverslips were coated with MTA Fillapex, iRoot SP and AH Plus Jet and each coverslip was placed onto the bottom of one well of a six-well plate for scanning electron microscopy (SEM) analysis. Before the cytotoxicity and SEM analysis, all samples were stored at 37ºC and at 95% humidity and 5% CO2 for 24 hours to set. The cellular viability was analyzed using MTS test (3-(4,5-dimethyl-thiazol-2-yl)-5-(3-carboxy-methoxy-phenyl)-2-(4-sulfo-phenyl)-2H-tetrazolium). The cytotoxic effects and SEM visualization of the tested materials were analyzed at 24-hour, 72-hour, one-week and two-week periods. Results On the 1st day, only MTA Fillapex caused cytotoxicity compared to negative control (NC) group (p<0.008). No significant difference was observed between the other tested materials at this period (p>0.05). After 14 days of incubation with the test materials, MTA Fillapex exhibited significantly higher cytotoxicity compared with iRoot SP, AH Plus Jet and the NC group (P<0.008). In the SEM analysis, the highest levels of cell attachment were observed for iRoot SP and the control group. After 24 hours, MTA Fillapex reduced the number of cells attached to the surface. Conclusions Within the limitations of this study, sealers exerted different cytotoxic effects on hTGSCs. Although all materials have exerted cellular toxicity, iRoot SP and AH Plus Jet may promote better attachment to hTGSCs. PMID:24037075

  5. Culture human mesenchymal stem cells with calcium phosphate cement scaffolds for bone repair.

    PubMed

    Weir, Michael D; Xu, Hockin H K

    2010-04-01

    Because of its moldability and excellent osteoconductivity, calcium phosphate cement (CPC) is highly promising for craniofacial and orthopedic applications. The objectives of this study were to investigate the response of human mesenchymal stem cells (hMSCs) to a high-strength CPC-chitosan scaffold and to examine cell proliferation and osteogenic differentiation. hMSCs were seeded onto CPC-chitosan composite, CPC control, and tissue culture polystyrene (TCPS). Alkaline phosphatase activity (ALP) and mineralization of hMSCs were measured. CPC-chitosan had a flexural strength (mean + or - SD; n = 5) of (19.5 + or - 1.4) MPa, higher than (8.0 + or - 1.4) MPa of CPC control (p < 0.05). The percentage of live hMSCs on CPC-chitosan was (90.5 + or - 1.3)% at 8 days, matching (90.7 + or - 3.8)% of CPC control (p > 0.1). The CPC-chitosan surface area covered by the attached hMSCs increased from (51 + or - 11)% at 1 day to (90 + or - 4)% at 8 days (p < 0.05), matching those of CPC control (p > 0.1). Hence, the CPC strength was significantly increased via chitosan without compromising the hMSC response. At 8 days, there was a significant increase in ALP of cells in osteogenic media (10.99 + or - 0.93) [(mM pNpp/min)/(microg DNA)] versus control media (3.62 + or - 0.40) (p < 0.05). hMSCs in osteogenic media exhibited greater mineralization area of (47.5 + or - 19.7)% compared with (6.1 + or - 2.3)% in control medium on TCPS (p < 0.05). In conclusion, hMSCs showed excellent attachment and viability on the strong and tough CPC-chitosan scaffold, matching the hMSC response on CPC control. hMSCs were successfully differentiated down the osteogenic lineage. Hence, the strong, in situ hardening CPC-chitosan scaffold may be useful as a moderate load-bearing vehicle to deliver hMSCs for maxillofacial and orthopedic bone tissue engineering. PMID:20091907

  6. Maintenance of proximal bone mass with an uncemented femoral stem analysis with dual-energy x-ray absorptiometry.

    PubMed

    Wixson, R L; Stulberg, S D; Van Flandern, G J; Puri, L

    1997-06-01

    Bone ingrowth into uncemented femoral implants with proximal porous coatings has been designed to avoid proximal stress shielding and preserve femoral strength. Dual-energy x-ray absorptiometry allows repeated quantitative analysis of anteroposterior scans of the proximal femur. By use of dual-energy x-ray absorptiometry and qualitative radiographic changes, 31 total hip arthroplasties with an individually designed, proximally porous-coated prosthesis were evaluated after surgery and at intervals up to 2 years. All implants appeared to achieve successful bone ingrowth and subsequent remodeling. At the most proximal level around the neck osteotomy, the postoperative loss of bone density at 6 months was -14.5%, which persisted at 24 months with -11.6%. At the level of the distal portion of the porous coating in the lower metaphysis, the density change was -8.7%, but bone had remodeled at 24 months with a change in density of only -1.0% compared with the immediate postoperative scan. With a design that results in reliable proximal ingrowth, this study predicts that after an initial decline in bone density, a positive bone remodeling response occurs that could lead to long-term stable fixation of the femoral implant. PMID:9195311

  7. Combining Concentrated Autologous Bone Marrow Stem Cells Injection With Core Decompression Improves Outcome for Patients with Early-Stage Osteonecrosis of the Femoral Head: A Comparative Study.

    PubMed

    Tabatabaee, Reza Mostafavi; Saberi, Sadegh; Parvizi, Javad; Mortazavi, Seyed Mohammad Javad; Farzan, Mahmoud

    2015-09-01

    The management of early-stage osteonecrosis of the femoral head (ONFH) remains challenging. This study aimed to evaluate the effects of core decompression and concentrated bone marrow implantation on ONFH. The study recruited 28 hips with early ONFH randomly assigned into two groups of core decompression with (group A) and without (group B) bone marrow injection. Patients were evaluated using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire, Visual Analogue Scale (VAS) pain index, and MRI. The mean WOMAC and VAS scores in all patients improved significantly (P<0.001). MRI showed a significant improvement in group A (P=0.046) and significant worsening in group B (P<0.001). Bone marrow stem cell injection with core decompression can be effective in early ONFH. PMID:26143238

  8. Periprosthetic Femoral Fracture With Broken Implant Insitu: - A Treatment Prospect

    PubMed Central

    Pal, Chandra Prakash; Singh, Pulkesh; Kumar, Deepak; Singh, Arpit

    2014-01-01

    Introduction: Fractures involving bones containing a component of a prosthetic joint are becoming more common. The causation is multifactorial but most of these injuries are associated with trivial trauma. The options available for operative management of these fractures include internal fixation of the fracture alone, fixation of the fracture with revision of the prosthesis, and reconstruction of proximal femur with either modified impaction bone grafting or proximal femoral replacement. Case Report: We present here a case of periprosthetic fracture Vancouver type B1 with a broken cemented bipolar prosthesis insitu, in which the broken implant was firmly fixed in the proximal fragment and could not be removed following which the whole of the proximal fragment along with the broken implant was removed and replaced by a customized steel long stem cemented mega prosthesis. Conclusion: This case is being presented on account of its unusual presentation and fracture pattern. A broken prosthesis along with a periprosthetic fracture is not a common incident. Thus the treatment had to be individualized. Since the prosthesis was well fixed, its broken stem could not be removed from the proximal fragment and so the whole of the proximal fragment along with stem was removed and replaced with a long stem custom made bipolar prosthesis. PMID:27298972

  9. Effects of a discoloration-resistant calcium aluminosilicate cement on the viability and proliferation of undifferentiated human dental pulp stem cells.

    PubMed

    Niu, Li-na; Watson, Devon; Thames, Kyle; Primus, Carolyn M; Bergeron, Brian E; Jiao, Kai; Bortoluzzi, Eduardo A; Cutler, Christopher W; Chen, Ji-hua; Pashley, David H; Tay, Franklin R

    2015-01-01

    Discoloration-resistant calcium aluminosilicate cement has been formulated to overcome the timely problem of tooth discoloration reported in the clinical application of bismuth oxide-containing hydraulic cements. The present study examined the effects of this experimental cement (Quick-Set2) on the viability and proliferation of human dental pulp stem cells (hDPSCs) by comparing the cellular responses with commercially available calcium silicate cement (white mineral trioxide aggregate; WMTA) after different aging periods. Cell viability and proliferation were examined using assays that examined plasma membrane integrity, leakage of cytosolic enzyme, caspase-3 activity for early apoptosis, oxidative stress, mitochondrial metabolic activity and intracellular DNA content. Results of the six assays indicated that both Quick-Set2 and WMTA were initially cytotoxic to hDPSCs after setting for 24 h, with Quick-Set2 being comparatively less cytotoxic than WMTA at this stage. After two aging cycles, the cytotoxicity profiles of the two hydraulic cements were not significantly different and were much less cytotoxic than the positive control (zinc oxide-eugenol cement). Based on these results, it is envisaged that any potential beneficial effect of the discoloration-resistant calcium aluminosilicate cement on osteogenesis by differentiated hDPSCs is more likely to be revealed after outward diffusion and removal of its cytotoxic components. PMID:26617338

  10. Effects of a discoloration-resistant calcium aluminosilicate cement on the viability and proliferation of undifferentiated human dental pulp stem cells

    PubMed Central

    Niu, Li-na; Watson, Devon; Thames, Kyle; Primus, Carolyn M.; Bergeron, Brian E.; Jiao, Kai; Bortoluzzi, Eduardo A.; Cutler, Christopher W.; Chen, Ji-hua; Pashley, David H.; Tay, Franklin R.

    2015-01-01

    Discoloration-resistant calcium aluminosilicate cement has been formulated to overcome the timely problem of tooth discoloration reported in the clinical application of bismuth oxide-containing hydraulic cements. The present study examined the effects of this experimental cement (Quick-Set2) on the viability and proliferation of human dental pulp stem cells (hDPSCs) by comparing the cellular responses with commercially available calcium silicate cement (white mineral trioxide aggregate; WMTA) after different aging periods. Cell viability and proliferation were examined using assays that examined plasma membrane integrity, leakage of cytosolic enzyme, caspase-3 activity for early apoptosis, oxidative stress, mitochondrial metabolic activity and intracellular DNA content. Results of the six assays indicated that both Quick-Set2 and WMTA were initially cytotoxic to hDPSCs after setting for 24 h, with Quick-Set2 being comparatively less cytotoxic than WMTA at this stage. After two aging cycles, the cytotoxicity profiles of the two hydraulic cements were not significantly different and were much less cytotoxic than the positive control (zinc oxide–eugenol cement). Based on these results, it is envisaged that any potential beneficial effect of the discoloration-resistant calcium aluminosilicate cement on osteogenesis by differentiated hDPSCs is more likely to be revealed after outward diffusion and removal of its cytotoxic components. PMID:26617338

  11. A randomised trial comparing a short and a standard-length metaphyseal engaging cementless femoral stem using radiostereometric analysis.

    PubMed

    McCalden, R W; Korczak, A; Somerville, L; Yuan, X; Naudie, D D

    2015-05-01

    This was a randomised controlled trial studying the safety of a new short metaphyseal fixation (SMF) stem. We hypothesised that it would have similar early clinical results and micromovement to those of a standard-length tapered Synergy metaphyseal fixation stem. Using radiostereometric analysis (RSA) we compared the two stems in 43 patients. A short metaphyseal fixation stem was used in 22 patients and a Synergy stem in 21 patients. No difference was found in the clinical outcomes pre- or post-operatively between groups. RSA showed no significant differences two years post-operatively in mean micromovement between the two stems (except for varus/valgus tilt at p = 0.05) (subsidence 0.94 mm (SD 1.71) vs 0.32 mm (SD 0.45), p = 0.66; rotation 0.96° (SD 1.49) vs 1.41° (SD 2.95), p = 0.88; and total migration 1.09 mm (SD 1.74) vs 0.73 mm (SD 0.72), p = 0.51). A few stems (four SMF and three Synergy) had initial migration > 1.0 mm but stabilised by three to six months, with the exception of one SMF stem which required revision three years post-operatively. For most stems, total micromovement was very low at two years (subsidence < 0.5 mm, rotation < 1.0°, total migration < 0.5 mm), which was consistent with osseous ingrowth. The small sample makes it difficult to confirm the universal applicability of or elucidate the potential contraindications to the use of this particular new design of stem. PMID:25922451

  12. Late fatigue fracture of a modern cemented [corrected] cobalt chrome stem for total hip arthroplasty: a report of 10 cases.

    PubMed

    Della Valle, Alejandro González; Becksaç, Burak; Anderson, John; Wright, Timothy; Nestor, Bryan; Pellicci, Paul M; Salvati, Eduardo A

    2005-12-01

    We report 10 fatigue fractures of a modern, cemented, cobalt chromium alloy stem (Osteonics Omnifit) for total hip arthroplasty occurring between 1995 and 2004. The primary total hip arthroplasties had been performed between 1989 and 1996. The average age at the time of surgery was 54 years (range, 34-70 years), and the average body mass index was 29 (range, 20-38). The time in situ of the prosthesis at the time of fracture averaged 8 years (range, 4-12 years). Intermediate follow-up radiographs before the fracture were available in 7 cases, all of which demonstrated loss of calcar support. Scanning electron microscopy of the fracture surfaces in 3 of the components showed porosity near the initiation site. Metallography of polished and etched cross sections near the fracture surface revealed large grain size. In the presence of a spontaneous onset of thigh pain at intermediate follow-up in patients with this stem, particularly if associated with loss of calcar support, a fatigue fracture should be considered. PMID:16376269

  13. Stubby stems: good things come in small packages.

    PubMed

    Lombardi, Adolph V; Berend, Keith R; Ng, Vincent Y

    2011-09-01

    Standard-length porous-coated tapered femoral stems perform exceedingly well in primary total hip arthroplasty (THA) at long-term follow-up. Nevertheless, there are multiple reasons to strongly consider the relatively new concept of short tapered stems. First, there is already a wide variation in the lengths of "standard" components and the ideal length is unknown. The goal of tapered stems is to load the proximal femur, and shortened stems accomplish this task. Second, while the distal extension may help prevent varus, unlike cemented stems, which are failure-prone with varus alignment, tapered designs are not. Additionally, elimination of the distal extension may reduce potential stress shielding. Third, short stems obviate problems with proximal-distal mismatch, excessive femoral bowing, diaphyseal deformities, and preexisting hardware. Fourth, implantation of smaller components requires less violation of bone and soft tissue, facilitating less invasive surgical approaches and favorable revision settings if necessary. Fifth, in comparison to hip resurfacing and other unconventional short-stem designs, tapered stems are familiar to most orthopedic surgeons and do not incur a steep learning curve. Finally, our early experience with this implant in 1750 THAs since 2006 has been excellent. In a series of >650 THA, compared to standard-length tapered stems, the short stem had equivalent clinical outcome scores, significantly fewer femoral fractures (12/389 [3.1%] vs 1/269 [0.4%]), and only 1 (1/269 [0.4%]) femoral revision (infection) at 2-year follow-up. Short stems represent the logical progression of a proven precedent in standard-length tapered stems. PMID:21902132

  14. A Dual Biomechanical Failure: Exeter Stem and Pubic Rami Insufficiency Fracture, following Hybrid Total Hip Arthroplasty

    PubMed Central

    Samra, Inderpaul; Paliobeis, Christos

    2015-01-01

    Introduction. Incidence of Exeter stem fracture is extremely uncommon. Pubic rami insufficiency fractures following arthroplasty are also rare. To our knowledge no cases of spontaneous stem failure with previous insufficiency fractures have yet been reported. Case Presentation. This report describes a case of spontaneous fracture through a cemented Exeter stem in a 66-year-old patient who had previously undergone a hybrid total hip replacement and was found to have bifocal pubic rami insufficiency fractures. The patient presented 18-year postprimary surgery with spontaneous fracture of the middle third of the cemented femoral stem and adjacent proximal femur. Conclusion. This report demonstrates a unique case of Exeter stem fracture with previous pelvic insufficiency fractures. The case adds to the rare occurrences of Exeter stem failure in the literature and highlights the risk of potential insufficiency fractures in patients undergoing total hip replacement. PMID:26236519

  15. In Vitro Assessment of Nanosilver-Functionalized PMMA Bone Cement on Primary Human Mesenchymal Stem Cells and Osteoblasts

    PubMed Central

    Pauksch, Linda; Hartmann, Sonja; Szalay, Gabor; Alt, Volker; Lips, Katrin S.

    2014-01-01

    Peri-prosthetic infections caused by multidrug resistant bacteria have become a serious problem in surgery and orthopedics. The aim is to introduce biomaterials that avoid implant-related infections caused by multiresistant bacteria. The efficacy of silver nanoparticles (AgNP) against a broad spectrum of bacteria and against multiresistant pathogens has been repeatedly described. In the present study polymethylmethacrylate (PMMA) bone cement functionalized with AgNP and/or gentamicin were tested regarding their biocompatibility with bone forming cells. Therefore, influences on viability, cell number and differentiation of primary human mesenchymal stem cells (MSCs) and MSCs cultured in osteogenic differentiation media (MSC-OM) caused by the implant materials were studied. Furthermore, the growth behavior and the morphology of the cells on the testing material were observed. Finally, we examined the induction of cell stress, regarding antioxidative defense and endoplasmatic reticulum stress. We demonstrated similar cytocompatibility of PMMA loaded with AgNP compared to plain PMMA or PMMA loaded with gentamicin. There was no decrease in cell number, viability and osteogenic differentiation and no induction of cell stress for all three PMMA variants after 21 days. Addition of gentamicin to AgNP-loaded PMMA led to a slight decrease in osteogenic differentiation. Also an increase in cell stress was detectable for PMMA loaded with gentamicin and AgNP. In conclusion, supplementation of PMMA bone cement with gentamicin, AgNP, and both results in bone implants with an antibacterial potency and suitable cytocompatibility in MSCs and MSC-OM. PMID:25485700

  16. In vitro assessment of nanosilver-functionalized PMMA bone cement on primary human mesenchymal stem cells and osteoblasts.

    PubMed

    Pauksch, Linda; Hartmann, Sonja; Szalay, Gabor; Alt, Volker; Lips, Katrin S

    2014-01-01

    Peri-prosthetic infections caused by multidrug resistant bacteria have become a serious problem in surgery and orthopedics. The aim is to introduce biomaterials that avoid implant-related infections caused by multiresistant bacteria. The efficacy of silver nanoparticles (AgNP) against a broad spectrum of bacteria and against multiresistant pathogens has been repeatedly described. In the present study polymethylmethacrylate (PMMA) bone cement functionalized with AgNP and/or gentamicin were tested regarding their biocompatibility with bone forming cells. Therefore, influences on viability, cell number and differentiation of primary human mesenchymal stem cells (MSCs) and MSCs cultured in osteogenic differentiation media (MSC-OM) caused by the implant materials were studied. Furthermore, the growth behavior and the morphology of the cells on the testing material were observed. Finally, we examined the induction of cell stress, regarding antioxidative defense and endoplasmatic reticulum stress. We demonstrated similar cytocompatibility of PMMA loaded with AgNP compared to plain PMMA or PMMA loaded with gentamicin. There was no decrease in cell number, viability and osteogenic differentiation and no induction of cell stress for all three PMMA variants after 21 days. Addition of gentamicin to AgNP-loaded PMMA led to a slight decrease in osteogenic differentiation. Also an increase in cell stress was detectable for PMMA loaded with gentamicin and AgNP. In conclusion, supplementation of PMMA bone cement with gentamicin, AgNP, and both results in bone implants with an antibacterial potency and suitable cytocompatibility in MSCs and MSC-OM. PMID:25485700

  17. A novel strontium(II)-modified calcium phosphate bone cement stimulates human-bone-marrow-derived mesenchymal stem cell proliferation and osteogenic differentiation in vitro.

    PubMed

    Schumacher, M; Lode, A; Helth, A; Gelinsky, M

    2013-12-01

    In the present study, the in vitro effects of novel strontium-modified calcium phosphate bone cements (SrCPCs), prepared using two different approaches on human-bone-marrow-derived mesenchymal stem cells (hMSCs), were evaluated. Strontium ions, known to stimulate bone formation and therefore already used in systemic osteoporosis therapy, were incorporated into a hydroxyapatite-forming calcium phosphate bone cement via two simple approaches: incorporation of strontium carbonate crystals and substitution of Ca(2+) by Sr(2+) ions during cement setting. All modified cements released 0.03-0.07 mM Sr(2+) under in vitro conditions, concentrations that were shown not to impair the proliferation or osteogenic differentiation of hMSCs. Furthermore, strontium modification led to a reduced medium acidification and Ca(2+) depletion in comparison to the standard calcium phosphate cement. In indirect and direct cell culture experiments with the novel SrCPCs significantly enhanced cell proliferation and differentiation were observed. In conclusion, the SrCPCs described here could be beneficial for the local treatment of defects, especially in the osteoporotic bone. PMID:23917042

  18. Fabrication of macroporous cement scaffolds using PEG particles: In vitro evaluation with induced pluripotent stem cell-derived mesenchymal progenitors.

    PubMed

    Sladkova, Martina; Palmer, Michael; Öhman, Caroline; Alhaddad, Rawan Jaragh; Esmael, Asmaa; Engqvist, Håkan; de Peppo, Giuseppe Maria

    2016-12-01

    Calcium phosphate cements (CPCs) have been extensively used in reconstructive dentistry and orthopedics, but it is only recently that CPCs have been combined with stem cells to engineer biological substitutes with enhanced healing potential. In the present study, macroporous CPC scaffolds with defined composition were fabricated using an easily reproduced synthesis method, with minimal fabrication and processing steps. Scaffold pore size and porosity, essential for cell infiltration and tissue ingrowth, were tuned by varying the content and size of polyethylene glycol (PEG) particles, resulting in 9 groups with different architectural features. The scaffolds were characterized for chemical composition, porosity and mechanical properties, then tested in vitro with human mesenchymal progenitors derived from induced pluripotent stem cells (iPSC-MPs). Biomimetic decellularized bone scaffolds were used as reference material in this study. Our manufacturing process resulted in the formation of macroporous monetite scaffolds with no residual traces of PEG. The size and content of PEG particles was found to affect scaffold porosity, and thus mechanical properties. Irrespective of pore size and porosity, the CPC scaffolds fabricated in this study supported adhesion and viability of human iPSC-MPs similarly to decellularized bone scaffolds. However, the architectural features of the scaffolds were found to affect the expression of bone specific genes, suggesting that specific scaffold groups could be more suitable to direct human iPSC-MPs in vitro toward an osteoblastic phenotype. Our simplistic fabrication method allows rapid, inexpensive and reproducible construction of macroporous CPC scaffolds with tunable architecture for potential use in dental and orthopedic applications. PMID:27612757

  19. Human Embryonic Stem Cell-Derived Mesenchymal Stem Cell Seeding on Calcium Phosphate Cement-Chitosan-RGD Scaffold for Bone Repair

    PubMed Central

    Chen, Wenchuan; Zhou, Hongzhi; Weir, Michael D.; Tang, Minghui

    2013-01-01

    Calcium phosphate cement (CPC) has in situ-setting ability and excellent osteoconductivity. Human embryonic stem cells (hESCs) are exciting for regenerative medicine due to their strong proliferative ability and multilineage differentiation capability. However, there has been no report on hESC seeding with CPC. The objectives of this study were to obtain hESC-derived mesenchymal stem cells (hESCd-MSCs), and to investigate hESCd-MSC proliferation and osteogenic differentiation on novel CPC with chitosan immobilized with RGD (CPC-chitosan-RGD). RGD was covalently bonded with chitosan, which was then incorporated into CPC. The CPC-chitosan-RGD scaffold had higher strength and toughness than CPC-chitosan control without RGD (p<0.05). hESCs were cultured to form embryoid bodies (EBs), and the MSCs were then migrated out of the EBs. Flow cytometry indicated that the hESCd-MSCs expressed typical surface antigen profile of MSCs. hESCd-MSCs had good viability when seeded on CPC scaffolds. The percentage of live cells and the cell density were significantly higher on CPC-chitosan-RGD than CPC-chitosan control. Scanning electron microscope examination showed hESCd-MSCs with a healthy spreading morphology adherent to CPC. hESCd-MSCs expressed high levels of osteogenic markers, including alkaline phosphatase, osteocalcin, collagen I, and Runx2. The mineral synthesis by the hESCd-MSCs on the CPC-chitosan-RGD scaffold was twice that for CPC-chitosan control. In conclusion, hESCs were successfully seeded on CPC scaffolds for bone tissue engineering. The hESCd-MSCs had good viability and osteogenic differentiation on the novel CPC-chitosan-RGD scaffold. RGD incorporation improved the strength and toughness of CPC, and greatly enhanced the hESCd-MSC attachment, proliferation, and bone mineral synthesis. Therefore, the hESCd-MSC-seeded CPC-chitosan-RGD construct is promising to improve bone regeneration in orthopedic and craniofacial applications. PMID:23092172

  20. Femoral nerve damage (image)

    MedlinePlus

    The femoral nerve is located in the leg and supplies the muscles that assist help straighten the leg. It supplies sensation ... leg. One risk of damage to the femoral nerve is pelvic fracture. Symptoms of femoral nerve damage ...

  1. Femoral nerve dysfunction

    MedlinePlus

    Neuropathy - femoral nerve; Femoral neuropathy ... Craig EJ, Clinchot DM. Femoral neuropathy. In: Frontera WR, Silver JK, Rizzo TD Jr, eds. Essentials of Physical Medicine and Rehabilitation: Musculoskeletal Disorders, Pain, and Rehabilitation . 3rd ...

  2. Long-Duration Spaceflight During the Bion-M1 Spaceflight Experiment Resulted in Significant Bone Loss in the Femoral Head and Alterations in Stem Cell Differentiation Potential in Male Mice

    NASA Astrophysics Data System (ADS)

    Blaber, Elizabeth; Almeida, Eduardo; Grigoryan, Eleonora; Globus, Ruth

    Scientific understanding of the effects of microgravity on mammalian physiology has been limited to short duration spaceflight experiments (10-15 days). As long duration and inter-planetary missions are being initiated, there is a great need to understand the long-term effects of spaceflight on various physiological processes, including stem cell-based tissue regeneration. Bion-M1, for the first time, enabled the possibility of studying the effects of 30-days of microgravity exposure on a mouse model with sufficient sample size to enable statistical analysis. In this experiment, we hypothesized that microgravity negatively impacts stem cell based tissue regeneration, such as bone remodeling and regeneration from hematopoietic and mesenchymal precursors, thereby resulting in tissue degeneration in mice exposed to spaceflight. To test this hypothesis we collected the pelvis and proximal femur from space-flown mice and asynchronous ground controls and analyzed bone and bone marrow using techniques including Microcomputed Tomography (MicroCT), and in-vitro differentiation and differentiating cell motility assays. To determine the effects of 30-days spaceflight on bone tissue mass, we used MicroCT to analyze the trabecular bone of the femoral head and the cortical bone of the femoral neck and mid-shaft. We found that spaceflight caused a 45% decrease in bone volume ratio, a 17% decrease in trabecular thickness, a 25% decrease in trabecular number, and a 17% increase in trabecular spacing of trabecular bone. Furthermore, structural model index and trabecular pattern factor were increased by 32% and 82% respectively indicating that 30-days spaceflight resulted not only in a large loss of trabecular bone but also in a decrease of bone strength indicators. Analysis of the femoral neck cortical bone showed an increase in marrow area and cortical porosity indicating an overall widening of the femoral neck. Interestingly, no significant alterations were found in the cortical

  3. Gene Expression Responses to Mechanical Stimulation of Mesenchymal Stem Cells Seeded on Calcium Phosphate Cement

    PubMed Central

    Gharibi, Borzo; Cama, Giuseppe; Capurro, Marco; Thompson, Ian; Deb, Sanjukta; Di Silvio, Lucy

    2013-01-01

    Introduction The aim of the study reported here was to investigate the molecular responses of human mesenchymal stem cells (MSC) to loading with a model that attempts to closely mimic the physiological mechanical loading of bone, using monetite calcium phosphate (CaP) scaffolds to mimic the biomechanical properties of bone and a bioreactor to induce appropriate load and strain. Methods Human MSCs were seeded onto CaP scaffolds and subjected to a pulsating compressive force of 5.5±4.5 N at a frequency of 0.1 Hz. Early molecular responses to mechanical loading were assessed by microarray and quantitative reverse transcription-polymerase chain reaction and activation of signal transduction cascades was evaluated by western blotting analysis. Results The maximum mechanical strain on cell/scaffolds was calculated at around 0.4%. After 2 h of loading, a total of 100 genes were differentially expressed. The largest cluster of genes activated with 2 h stimulation was the regulator of transcription, and it included FOSB. There were also changes in genes involved in cell cycle and regulation of protein kinase cascades. When cells were rested for 6 h after mechanical stimulation, gene expression returned to normal. Further resting for a total of 22 h induced upregulation of 63 totally distinct genes that were mainly involved in cell surface receptor signal transduction and regulation of metabolic and cell division processes. In addition, the osteogenic transcription factor RUNX-2 was upregulated. Twenty-four hours of persistent loading also markedly induced osterix expression. Mechanical loading resulted in upregulation of Erk1/2 phosphorylation and the gene expression study identified a number of possible genes (SPRY2, RIPK1, SPRED2, SERTAD1, TRIB1, and RAPGEF2) that may regulate this process. Conclusion The results suggest that mechanical loading activates a small number of immediate-early response genes that are mainly associated with transcriptional

  4. Atypical periprosthetic femoral fracture: a case report.

    PubMed

    Woo, S B; Choi, S T; Chan, W L

    2016-08-01

    We report an 82-year-old woman who underwent fixation with a long-spanning cable-plate for a bisphosphonate-induced Vancouver B1 periprosthetic femoral fracture. Non-union and breakage of the plate occurred at 16 months and necessitated revision surgery using a long-stem femoral prosthesis augmented with a cable-plate construct. Bone union was achieved eventually after 10 months. PMID:27574277

  5. Femoral Component Survival in Hybrid Total Knee Arthroplasty.

    PubMed

    Perry, Clayton R; Perry, Kevin I

    2016-05-01

    Although the majority of North American surgeons perform total knee arthroplasty by cementing both the femoral and the tibial components, hybrid fixation with a press-fit femur and cemented tibia is an alternative form of total knee arthroplasty performed by some. Currently, there is a paucity of literature evaluating long-term outcomes after hybrid total knee arthroplasty. As such, the purpose of the current study was to describe the long-term results of total knee arthroplasty performed using the hybrid technique. The authors retrospectively reviewed a total of 77 hybrid total knee arthroplasties with at least 12 years of follow-up. Clinical and radiographic evaluations were performed to determine patient function and the incidence of femoral component failure after hybrid total knee arthroplasty. At the time of last follow-up, 76 of 77 (99%) of the femoral components remained in place without evidence of loosening. One femoral component failed due to aseptic loosening and was ultimately revised to a cemented femoral component without further complication. In addition, 1 tibial component and 2 patellar components failed due to aseptic loosening. Four tibial polyethylene liners were revised for polyethylene wear. In conclusion, press-fit fixation of the femoral component is a reliable and durable alternative to cemented fixation. [Orthopedics. 2016; 39(3):181-186.]. PMID:27135453

  6. Arthroplasty in Femoral Head Osteonecrosis

    PubMed Central

    Nam, Dong Cheol; Jung, Kwangyoung

    2014-01-01

    Osteonecrosis of the femoral head is a destructive joint disease requiring early hip arthroplasty. The polyethylene-metal design using a 22-mm femoral head component, introduced by Charnley in 1950, has been widely used for over half a century. Since then, different materials with the capacity to minimize friction between bearing surfaces and various cement or cementless insert fixations have been developed. Although the outcome of second and third generation designs using better bearing materials and technologies has been favorable, less favorable results are seen with total hip arthroplasty in young patients with osteonecrosis. Selection of appropriate materials for hip arthroplasty is important for any potential revisions that might become inevitable due to the limited durability of a prosthetic hip joint. Alternative hip arthroplasties, which include hemiresurfacing arthroplasty and bipolar hemiarthroplasty, have not been found to have acceptable outcomes. Metal-on-metal resurfacing has recently been suggested as a feasible option for young patients with extra physical demands; however, concerns about complications such as hypersensitivity reaction or pseudotumor formation on metal bearings have emerged. To ensure successful long-term outcomes in hip arthroplasty, factors such as insert stabilization and surfaces with less friction are essential. Understanding these aspects in arthroplasty is important to selection of proper materials and to making appropriate decisions for patients with osteonecrosis of the femoral head. PMID:27536561

  7. Optimizing Stability in Femoral Neck Fracture Fixation.

    PubMed

    Ye, Ye; Hao, Jiandong; Mauffrey, Cyril; Hammerberg, E Mark; Stahel, Philip F; Hak, David J

    2015-10-01

    Optimizing stability of femoral neck fracture fixation is important in obtaining a successful outcome. The mechanical problems and strategies for achieving optimal stability differ depending on patients' age and degree of osteoporosis. Femoral neck fractures in younger adults usually result from high-energy trauma and have a vertical fracture pattern. Strategies for optimizing fixation stability in this group include placing additional screws at right angles to the fracture plane and medial buttress plate augmentation. In elderly patients, screw position relative to the intact cortical femoral neck bone is of critical importance. Additional strategies for optimizing fixation stability in this group include the concept of length stable fixation, use of adjunctive calcium phosphate cement, and use of novel fixed angle fixation implants. PMID:26488776

  8. Slipped capital femoral epiphysis

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/000972.htm Slipped capital femoral epiphysis To use the sharing features on this page, please enable JavaScript. A slipped capital femoral epiphysis is a separation of the ball ...

  9. Cement applicator use for hip resurfacing arthroplasty.

    PubMed

    Jaeger, Sebastian; Rieger, Johannes S; Obermeyer, Beate; Klotz, Matthias C; Kretzer, J Philippe; Bitsch, Rudi G

    2015-05-01

    We compared the manufacturer recommended cementing technique for a femoral hip resurfacing implant (BHR, S&N) to a newly designed cement applicator on 20 porous carbon foam specimens. Substantial design changes and improvements of the cement applicator were necessary: The diameter and number of the cement escaping holes at the top of the applicator were optimized for medium viscosity cement. It was necessary to add four separate air inlet holes with large diameters. The inner shape of the applicator had to be adapted to the BHR design with a circular extending chamfer in the proximal region, a parallel inner wall and a second chamfer distally. The interface temperatures showed no risk for heat necrosis using both techniques. The cement penetration depth was more uniform and significantly reduced for the applicator cementing technique (4.34 ± 1.42 mm, 6.42 ± 0.43 mm, p = 0.001). The cement-applicator showed no cement defects compared to a large defect length (0.0 ± 0.0 mm, 10.36 ± 1.10 mm, p < 0.001) with the manufacturer recommended cementing technique. The cement applicator technique appears to be effective for a homogenous cement distribution without cement defects and safe with a lower risk of polar over-penetration. PMID:25772262

  10. The Morphology of the Proximal Femoral Canal Continues to Change in the Very Elderly: Implications for Total Hip Arthroplasty.

    PubMed

    Boymans, Tim A E J; Heyligers, Ide C; Grimm, Bernd

    2015-12-01

    A shape mismatch between cementless stems and the femoral canal of very elderly patients could partly explain the inferior performance of cementless compared to cemented stems in this age group. Influences of age and gender on canal morphology were investigated by measuring coronal/sagittal dimensions on CT-scans of subjects ≥80 years old (n = 117) and subjects < 80 years old (n = 51). Absolute canal dimensions like width were larger in octogenarians than in younger subjects. These differences were larger in the sagittal plane than in the coronal plane (P < 0.001). Canal flaring changed asymmetrically with increased medial and less lateral flaring in octogenarians. Age-related changes were mainly observed in females and should be taken into consideration for implant design, selection and implantation in octogenarians. PMID:26187385

  11. Does the lateral plate need to overlap the stem to mitigate stress concentration when treating Vancouver C periprosthetic supracondylar femur fracture?

    PubMed

    Kubiak, Erik N; Haller, Justin M; Kemper, Dan D; Presson, Angela P; Higgins, Thomas F; Horwitz, Daniel S

    2015-01-01

    The effect of construct length on cortical strain and load to failure between locked compression plating and cemented femoral stem in a fall model was analyzed. Eight Sawbone femurs with cemented stems were instrumented with increasing fixation lengths starting 8cm distal to stem tip and progressing proximally to overlapping constructs. Uniaxial strain gauges measured cortical strain. Load to failure was performed with 8cm gap between implants, 2cm gap, and proximally overlapping configurations. Strain was significantly reduced as the 8cm gap transitioned to an overlapped construct with most comparisons. Load to failure in the overlapped construct was 273% greater compared to 2cm gap construct. Overlapping the stem with a locking compression plate resulted in reduced strain and increased load to failure. PMID:25443562

  12. Load-transfer analysis after insertion of cementless anatomical femoral stem using pre- and post-operative CT images based patient-specific finite element analysis.

    PubMed

    Yamako, Go; Chosa, Etsuo; Zhao, Xin; Totoribe, Koji; Watanabe, Shinji; Sakamoto, Takero; Nakane, Nobutake

    2014-06-01

    Periprosthetic bone remodeling is commonly seen after total hip arthroplasty, but the remodeling pattern differs among patients even in those implanted with the same stem. Remodeling occurs mainly because of the difference in load transmitted from the stem to the femur. In this study, we evaluated the load-transfer pattern in eight female patients implanted with an anatomical stem on an individual basis by patient-specific finite element analysis that is based on pre- and postoperative computed tomography images. Load transfer was evaluated using interface stress between the stem and bone. One of eight patients demonstrated proximal dominant load transfer, while the other patients demonstrated a distal dominant pattern. The results of our biomechanical simulations reveal the differences in load-transfer pattern after surgery among patients with the same anatomical stem. PMID:24629623

  13. A modified PMMA cement (Sub-cement) for accelerated fatigue testing of cemented implant constructs using cadaveric bone.

    PubMed

    Race, Amos; Miller, Mark A; Mann, Kenneth A

    2008-10-20

    Pre-clinical screening of cemented implant systems could be improved by modeling the longer-term response of the implant/cement/bone construct to cyclic loading. We formulated bone cement with degraded fatigue fracture properties (Sub-cement) such that long-term fatigue could be simulated in short-term cadaver tests. Sub-cement was made by adding a chain-transfer agent to standard polymethylmethacrylate (PMMA) cement. This reduced the molecular weight of the inter-bead matrix without changing reaction-rate or handling characteristics. Static mechanical properties were approximately equivalent to normal cement. Over a physiologically reasonable range of stress-intensity factor, fatigue crack propagation rates for Sub-cement were higher by a factor of 25+/-19. When tested in a simplified 2 1/2-D physical model of a stem-cement-bone system, crack growth from the stem was accelerated by a factor of 100. Sub-cement accelerated both crack initiation and growth rate. Sub-cement is now being evaluated in full stem/cement/femur models. PMID:18774136

  14. Cytotoxic Effects of Various Mineral Trioxide Aggregate Formulations, Calcium-Enriched Mixture and a New Cement on Human Pulp Stem Cells

    PubMed Central

    Jaberiansari, Zahra; Naderi, Seddigheh; Tabatabaei, Fahimeh Sadat

    2014-01-01

    Introduction: This in vitro study compared the cytotoxic effects of three commercially available MTA formulations naming ProRoot MTA (PMTA), Angelus MTA (AMTA), and Root MTA (RMTA), with calcium-enriched mixture (CEM) cement and a new nanohybrid MTA (NMTA) on human dental pulp stem cells (DPSC). Methods and Materials: Four disc-shaped specimens of each material were prepared. After completion of setting, 2 different (neat and 1/2) elutes of the test materials were made. Then in each cavity of a 96-well plate, 3000 cells were seeded and incubated in a humidified incubator with 5% CO2 and 95% air at 37°C for 24 h. After this period, the culture medium of each well was replaced with 200 μL of test material elutes. Plain culture medium was used as the negative control and distilled water as the positive control group. Cell viability was assessed using 2, 5-diphenyl-SH-tetrazelium bromide colorimetric assay, aka Mosmann’s tetrazolium toxicity (MTT) assay, at three time intervals (24, 48, and 72 h after mixing). Data were analyzed using the ANOVA and Tukey’s post hoc test (P=0.05). Results: After 24 h, the viability of cells in neat concentration had no significant differences (P>0.05) except for the NMTA. However, CEM and AMTA, at 1/2 concentration exerted significant proliferative effects on cells. At 48 and 72-h intervals, significant proliferation of DPSCs was seen in all samples, except for the NMTA which exerted toxic effects on cells. Conclusion: All of the three commercial MTAs and CEM cement showed comparative biocompatibility. However, NMTA had cytotoxic effects on DPSCs at all the time intervals. PMID:25386208

  15. Intraoperative measurement of rotational stability of femoral components of total hip arthroplasty.

    PubMed

    Harris, W H; Mulroy, R D; Maloney, W J; Burke, D W; Chandler, H P; Zalenski, E B

    1991-05-01

    High out-of-plane forces acting on the hip joint can produce important rotational micromotion of the femoral component. This micromotion at the prosthesis interface may be detrimental to the stability of the implant. In cementless femoral implants this could prevent bone ingrowth, and in the cemented component this could cause generation of particulate debris, lysis, and loosening. The introduction of the torque wrench micrometer for assessment of intraoperative femoral component stability can quantify the initial stability of primary cementless femoral components and critically evaluate the stability (at either the initial or revision arthroplasty) of both cemented and cementless femoral components. It allows the surgeon to produce a known torque in the direction and magnitude of the out-of-plane forces that load the hip in vivo. PMID:2019039

  16. Results of revision total hip arthroplasty with modular, titanium-tapered femoral stems in severe proximal metaphyseal and diaphyseal bone loss.

    PubMed

    Palumbo, Brian T; Morrison, Kurt L; Baumgarten, Adam S; Stein, Mathew I; Haidukewych, George J; Bernasek, Thomas L

    2013-04-01

    Evidence supporting modular, tapered stems for severe proximal metaphyseal and diaphyseal bone loss is limited. We report our clinical experience with its use for severely deficient femurs. Of 211 revision total hip arthroplasties (THAs), 18 tapered, modular titanium stems were implanted in Paprosky type III and IV femurs. Clinical data were reviewed for function, stability, structural failure and revision surgery at a mean follow-up of 4.5years. The overall survival rate was 94%. One required revision due to infection and subsidence. The mean subsidence was 3.5mm and the mean pre- and post-operative Harris Hip score was 56 and 79, respectively. In surviving cases, patients achieved satisfactory function and there were no mechanical failures. Modular, tapered stems demonstrated acceptable outcomes for management of severe proximal metaphyseal and diaphyseal defects. PMID:23273565

  17. Bone cement

    PubMed Central

    Vaishya, Raju; Chauhan, Mayank; Vaish, Abhishek

    2013-01-01

    The knowledge about the bone cement is of paramount importance to all Orthopaedic surgeons. Although the bone cement had been the gold standard in the field of joint replacement surgery, its use has somewhat decreased because of the advent of press-fit implants which encourages bone in growth. The shortcomings, side effects and toxicity of the bone cement are being addressed recently. More research is needed and continues in the field of nanoparticle additives, enhanced bone–cement interface etc. PMID:26403875

  18. Biofunctionalized Calcium Phosphate Cement to Enhance the Attachment and Osteodifferentiation of Stem Cells Released from Fast-Degradable Alginate-Fibrin Microbeads

    PubMed Central

    Chen, Wenchuan; Weir, Michael D.

    2012-01-01

    Stem cell-encapsulating microbeads could be mixed into a paste such as calcium phosphate cement (CPC), where the microbeads could protect the cells from the mixing and injection forces. After being placed, the microbeads could quickly degrade to release the cells throughout the scaffold, while creating macropores. The objectives of this study were to (1) construct alginate-fibrin microbeads encapsulating human umbilical cord mesenchymal stem cells (hUCMSCs) embedded in the surface of novel biofunctionalized CPC and (2) investigate microbead degradation, cell release, and osteodifferentiation on CPC. Hydrogel microbeads were fabricated that encapsulated hUCMSCs at 1×106 cells/mL. CPC was biofunctionalized with fibronectin (Fn) and Arg-Gly-Asp (RGD). Four scaffolds were tested: CPC control, CPC mixed with Fn, CPC mixed with RGD, and CPC grafted with RGD. The degradable microbeads released hUCMSCs at 7 days, which attached to CPC. Adding Fn or RGD to CPC greatly improved cell attachment. CPC grafted with RGD showed the fastest cell proliferation, with cell density being ninefold that on CPC control. The released hUCMSCs underwent osteodifferentiation. Alkaline phosphatase, osteocalcin, collagen 1, and runt-related transcription factor 2 (Runx2) gene expression increased by 10 to 30 fold at 7–21 days, compared with day 1. The released cells on CPC synthesized bone minerals, with the mineralization amount at 21 days being two orders of magnitude higher than that at 7 days. In conclusion, alginate-fibrin microbeads embedded in CPC surface were able to quickly release the hUCMSCs that attached to biofunctionalized CPC. Incorporating Fn and RGD into CPC greatly improved cell function, and CPC grafted with RGD had the fastest cell proliferation. The released cells on CPC differentiated into the osteogenic lineage and synthesized bone minerals. The new biofunctionalized CPC with hUCMSC-encapsulating microbeads is promising for bone regeneration applications. PMID:22435653

  19. CIRCUMFERENTIAL PROXIMAL FEMORAL ALLOGRAFTS IN TOTAL HIP ARTHROPLASTY REVISION SURGERY

    PubMed Central

    Roos, Bruno Dutra; Roos, Milton Valdomiro; Júnior, Antero Camisa; Lampert, Henrique Bonotto; da Silva, Matheus Luis

    2015-01-01

    Objective: To evaluate the clinical and radiographic results from patients who underwent femoral reconstruction secondary to loosening of total hip arthroplasty, using circumferential proximal femoral allografts and cemented implants. Methods: A retrospective study was conducted on 32 patients (33 hips) who underwent femoral reconstruction secondary to loosening of total hip arthroplasty, using circumferential proximal femoral allografts and cemented implants. Among these patients, 28 (29 hips) fulfilled all the requirements for this study. The mean follow-up was five years and two months. The clinical evaluation was done in accordance with the Harris Hip Score. Radiographically, the patients were assessed regarding reabsorption and consolidation of the allograft, migration of the greater trochanter, stability of the femoral component and heterotypic calcification. Results: The average preoperative Harris Hip Score was 32 points. At the last postoperative follow-up, the average score was 82 points. Allograft resorption of some degree was seen in nine hips (31%). Regarding consolidation, 24 cases (82.8%) showed full consolidation, three (10.3%) showed partial consolidation and two (6.9%) showed pseudarthrosis. All femoral components were stable. According to the criteria established, 27 cases (93.1%) were considered to be successful reconstructions after a mean follow-up of five years and two months. Conclusion: From the results obtained, it was concluded that use of circumferential proximal femoral allografts in selected cases of femoral reconstruction secondary to loosening of arthroplasty presented a high survival rate from the reconstruction over an average follow-up of five years and two months. PMID:27047896

  20. Slipped capital femoral epiphysis

    MedlinePlus

    A slipped capital femoral epiphysis is a separation of the ball of the hip joint from the thigh bone (femur) at ... A slipped capital femoral epiphysis may affect both hips. An epiphysis is an area at the end of a long bone . ...

  1. [Delayed hypoxia after the surgical correction of femoral neck fracture].

    PubMed

    Goh, R; Mori, K; Abe, T; Kohyama, A; Minato, A

    1996-11-01

    We investigated perioperative blood gas changes in 26 patients scheduled for surgical correction of femoral neck fracture under epidural anesthesia. Arterial blood gases during spontaneous air respiration were measured eight times during the femoral neck prosthetic replacements (n = 16), and four times during osteosynthesis (n = 10). In the patients who received femoral neck replacements using bone cement (n = 8), arterial oxygen tension decreased significantly four hours after insertion of prosthesis, and did not recover during two postoperative days. In contrast, in the patients who received cementless femoral neck replacements (n = 8), arterial oxygen tension tended to decrease but not significantly, and returned to normal on the second postoperative day. In the patients who received osteosynthesis, arterial oxygen tension did not change. We suspected that the causes of delayed hypoxia in the femoral neck replacements were vascular endothelial cell injury in the lung by free fatty acid originating from fat embolism, and/or microthrombosis resulting from activated coagulation system. Bone cement was thought to intensify fat embolism because of elevated intramedullary pressure in the femur. PMID:8953864

  2. Cement disease.

    PubMed

    Jones, L C; Hungerford, D S

    1987-12-01

    Does "cement disease" exist? The bony environment surrounding a loosened cemented prosthesis is an abnormal pathologic condition which, if left unattended, will progress to a total failure of the joint including an inhibition of function and immobilizing pain. That biomaterial properties of the cement used for fixation also contribute to the pathologic state separates this disease from other modes of loosening. This leads inevitably to the conclusion that "cement disease" does exist. Methyl methacrylate has revolutionized the treatment of severe joint dysfunction. There can be no doubt that improving surgical technique, cement handling, and the cement itself will continue to improve the results and reduce the incidence of failure due to loosening. Cement is undoubtedly satisfactory for elderly patients with low activity levels and relatively short life expectancies. However, because of the inherent biologic and biomechanical properties of methyl methacrylate, it is unlikely that it can be rendered satisfactory in the long run for the young, the active, or the overweight patient, for whom alternatives are currently being sought. In such cases, the elimination of "cement disease" can only occur with the elimination of cement. Alternatives include the search for other grouting materials and the development of prostheses with satisfactory surfaces for either press-fit or biologic ingrowth. PMID:3315375

  3. Fracture of the femoral component associated with polyethylene wear and osteolysis after total knee arthroplasty.

    PubMed

    Huang, C H; Yang, C Y; Cheng, C K

    1999-04-01

    Fracture of the femoral component associated with polyethylene wear and osteolysis after total knee arthroplasty (TKA) has not been well reported before. A 63-year-old man with osteoarthritis of the right knee underwent TKA with a New Jersey LCS Knee, with cementing on the tibia and patella but not on the femoral component. After 42 months, in addition to wearing of polyethylene of the tibia and patella, severe osteonecrosis of the medial femoral condyle was noted. Osteonecrosis caused loss of osseous support of the medial flange of the femoral component, and the bone ingrowth of the central and lateral flange to the distal femur was so good that it overcame the yield stress of the metal of the femoral component and caused fracture of the femoral component. The osteolytic area was filled with autogenous iliac bone, and a new femoral component was inserted and cemented. The patient's condition became satisfactory with relief of pain. Although uncommon, fracture of the femoral component does occur associated with polyethylene wear and osteolysis. PMID:10220194

  4. Early subsidence of shape-closed hip arthroplasty stems is associated with late revision

    PubMed Central

    van der Voort, Paul; Pijls, Bart G; Nieuwenhuijse, Marc J; Jasper, Jorrit; Fiocco, Marta; Plevier, Josepha W M; Middeldorp, Saskia; Valstar, Edward R; Nelissen, Rob G H H

    2015-01-01

    Background and purpose Few studies have addressed the association between early migration of femoral stems and late aseptic revision in total hip arthroplasty. We performed a meta-regression analysis on 2 parallel systematic reviews and meta-analyses to determine the association between early migration and late aseptic revision of femoral stems. Patients and methods Of the 2 reviews, one covered early migration data obtained from radiostereometric analysis (RSA) studies and the other covered long-term aseptic revision rates obtained from survival studies with endpoint revision for aseptic loosening. Stems were stratified according to the design concept: cemented shape-closed, cemented force-closed, and uncemented. A weighted regression model was used to assess the association between early migration and late aseptic revision, and to correct for confounders. Thresholds for acceptable and unacceptable migration were determined in accordance with the national joint registries (≤ 5% revision at 10 years) and the NICE criteria (≤ 10% revision at 10 years). Results 24 studies (731 stems) were included in the RSA review and 56 studies (20,599 stems) were included in the survival analysis review. Combining both reviews for the 3 design concepts showed that for every 0.1-mm increase in 2-year subsidence, as measured with RSA, there was a 4% increase in revision rate for the shape-closed stem designs. This association remained after correction for age, sex, diagnosis, hospital type, continent, and study quality. The threshold for acceptable migration of shape-closed designs was defined at 0.15 mm; stems subsiding less than 0.15 mm in 2 years had revision rates of less than 5% at 10 years, while stems exceeding 0.15 mm subsidence had revision rates of more than 5%. Interpretation There was a clinically relevant association between early subsidence of shape-closed femoral stems and late revision for aseptic loosening. This association can be used to assess the safety of

  5. Accuracy of femoral templating in reproducing anatomical femoral offset in total hip replacement.

    PubMed

    Davies, H; Foote, J; Spencer, R F

    2007-01-01

    Restoration of hip biomechanics is a crucial component of successful total hip replacement. Preoperative templating is recommended to ensure that the size and orientation of implants is optimised. We studied how closely natural femoral offset could be reproduced using the manufacturers' templates for 10 femoral stems in common use in the UK. A series of 23 consecutive preoperative radiographs from patients who had undergone unilateral total hip replacement for unilateral osteoarthritis of the hip was employed. The change in offset between the templated position of the best-fitting template and the anatomical centre of the hip was measured. The templates were then ranked according to their ability to reproduce the normal anatomical offset. The most accurate was the CPS-Plus (Root Mean Square Error 2.0 mm) followed in rank order by: C stem (2.16), CPT (2.40), Exeter (3.23), Stanmore (3.28), Charnley (3.65), Corail (3.72), ABG II (4.30), Furlong HAC (5.08) and Furlong modular (7.14). A similar pattern of results was achieved when the standard error of variability of offset was analysed. We observed a wide variation in the ability of the femoral prosthesis templates to reproduce normal femoral offset. This variation was independent of the seniority of the observer. The templates of modern polished tapered stems with high modularity were best able to reproduce femoral offset. The current move towards digitisation of X-rays may offer manufacturers an opportunity to improve template designs in certain instances, and to develop appropriate computer software. PMID:19197861

  6. Identification of femoral head center of bipolar hemiarthroplasy in radiostereometric analysis with elementary geometrical shape models.

    PubMed

    Tsukanaka, Masako; Röhrl, Stephan M; von Schewelov, Thord; Nordsletten, Lars

    2016-02-01

    Elementary geometrical shape (EGS) models are useful in radiostereometric analysis (RSA) on hip stems because tantalum markers attached to the stems can be omitted. In order to create an EGS model of a femoral stem, the center of the femoral head has to be identified. The contour of the femoral head is recommended to be used. However, the contour of the femoral head cannot be detected exclusively by computer if it is combined with a bipolar head or a metal cup. We therefore hypothesized that the contour of the outer head of bipolar hemiarthroplasty can be included in the EGS model as well as the femoral head contour. We calculated the time required for the detection of the contour, the precision of analysis and the stem micromotion at 2 years using the two different methods in the same picture set and compared the results. The detection of the bipolar head contour was 10 times faster than that of the femoral head contour. The precision for subsidence was 0.16 mm in EGS RSA with the femoral head contour, and 0.15 mm with the bipolar head contour (p=0.68). The precisions were comparable and clinically acceptable. There was no significant difference between the results of the 2-year micromotion with the two different methods. We conclude that this new method is applicable to measure stem micromotion of hemi-arthroplasty with EGS RSA and the method facilitates the Radiostereometric analysis. PMID:26705109

  7. Traumatic subchondral fracture of the femoral head in a healed trochanteric fracture

    PubMed Central

    Lee, Sang Yang; Niikura, Takahiro; Iwakura, Takashi; Kurosaka, Masahiro

    2014-01-01

    An 82-year-old woman sustained a trochanteric fracture of the left femur after a fall. Fracture fixation was performed using proximal femoral nail antirotation (PFNA) II, and she was able to walk with a T-cane after 3 months. Eleven months following the operation, the patient presented with left hip pain after a fall. Radiographs showed a subchondral collapse of the femoral head located above the blade tip. The authors removed the PFNA-II and subsequently performed cemented bipolar hemiarthroplasty. Histological evaluation of the femoral head showed osteoporosis with no evidence of osteonecrosis. Repair tissue, granulation tissue and callus formation were seen at the collapsed subchondral area. Based on these findings, a traumatic subchondral fracture of the femoral head in a healed trochanteric fracture was diagnosed. A traumatic subchondral fracture of the femoral head may need to be considered as a possible diagnosis after internal fixation of the trochanteric fracture. PMID:25015169

  8. STEM?!?!

    ERIC Educational Resources Information Center

    Merrill, Jen

    2012-01-01

    The author's son has been an engineer since birth. He never asked "why" as a toddler, it was always "how's it work?" So that he wanted a STEM-based home education was no big surprise. In this article, the author considers what kind of curricula would work best for her complex kid.

  9. Periprosthetic Atypical Femoral Fracture-like Fracture after Hip Arthroplasty: A Report of Three Cases

    PubMed Central

    Lee, Kyung-Jae; Jang, Hyung-Kyu; Ye, Hee-Uk; Lim, Kyung-Hwan

    2015-01-01

    Atypical femoral fractures are stress or insufficient fractures induced by low energy trauma or no trauma and have specific X-ray findings. Although the American Society for Bone and Mineral Research has excluded periprosthetic fractures from the definition of an atypical femoral fracture in 2013, this is still a matter of controversy because some authors report periprosthetic fractures showing specific features of atypical fractures around a well-fixed femoral stem. We report 3 cases of periprosthetic femur fractures that had specific radiographic features of atypical femoral fractures in patients with a history of prolonged bisphosphonate use; we also review relevant literature.

  10. Periprosthetic Atypical Femoral Fracture-like Fracture after Hip Arthroplasty: A Report of Three Cases.

    PubMed

    Lee, Kyung-Jae; Min, Byung-Woo; Jang, Hyung-Kyu; Ye, Hee-Uk; Lim, Kyung-Hwan

    2015-09-01

    Atypical femoral fractures are stress or insufficient fractures induced by low energy trauma or no trauma and have specific X-ray findings. Although the American Society for Bone and Mineral Research has excluded periprosthetic fractures from the definition of an atypical femoral fracture in 2013, this is still a matter of controversy because some authors report periprosthetic fractures showing specific features of atypical fractures around a well-fixed femoral stem. We report 3 cases of periprosthetic femur fractures that had specific radiographic features of atypical femoral fractures in patients with a history of prolonged bisphosphonate use; we also review relevant literature. PMID:27536624

  11. Exactech Opteon Femoral Component Fracture 12 Years after Arthroplasty

    PubMed Central

    Patel, Shaun P.; Antoci, Valentin; Kadzielski, John J.; Vrahas, Mark S.

    2016-01-01

    Arthroplasty implant fracture is a rare but critical complication that requires difficult revision surgery, often with poor results, patient disability, and significant cost. Several reports show component fracture either at the stem or at the neck interface after a relatively short postoperative course. We report such failure after 12 years, suggesting no safe period after which femoral implant fracture does not occur. PMID:26955493

  12. Prevention of cement leakage into the hip joint by a standard cement plug during PFN-A cement augmentation: a technical note.

    PubMed

    Hanke, M; Djonov, V; Tannast, M; Keel, M J; Bastian, J D

    2016-06-01

    Medial penetration of the helical blade into the hip joint after fixation of trochanteric fractures using the proximal femur nail antirotation (PFN-A) is a potential failure mode. In low demand patients a blade exchange with cement augmentation may be an option if conversion to total hip arthroplasty is unfeasible to salvage the cut-through. This article describes a technique to avoid intraarticular cement leakage using a cement plug to close the defect in the femoral head caused by the cut-through. PMID:27010468

  13. Standard anatomical medullary locking (AML) versus tricalcium phosphate-coated AML femoral prostheses

    PubMed Central

    Johnston, D.W.C. (Bill); Davies, Donna M.; Beaupré, Lauren A.; Lavoie, Guy

    2001-01-01

    Objectives To compare the preliminary rate and amount of bony ingrowth and calcar resorption between patients receiving either a standard anatomical medullary locking (AML) or a tricalcium phosphate (TCP)-coated AML femoral prosthesis and to compare preliminary clinical results. Design A prospective, randomized, double-blind clinical trial. Setting An acute care tertiary institution. Patients Between January 1993 and March 1995, 92 patients underwent primary total hip arthroplasty (THA). They were randomized to 2 groups of 46 — a control group or a treatment group. Of the 46 subjects enrolled in each group, no significant differences were seen preoperatively with respect to age, sex, diagnosis, clinical and radiographic assessment. Seventy-one patients were followed up for 24 months. Interventions Insertion of either a standard AML femoral implant (control group) or a TCP-coated AML femoral implant (treatment group). Outcome measures The degree of hypertrophy, calcar atrophy and the number of spot welds on standard postoperative radiographs at 6, 12 and 24 months. Clinically, assessment according to the Société internationale de chirurgie orthopédique et de traumatologie (SICOT) scale and a 100-point visual analogue scale (VAS) for pain. Results There were no prosthetic stem revisions in either group at the 24-month follow-up. Radiographically, bony ingrowth was not significantly different in the TCP-coated stem, by χ2 analysis of the degree of hypertrophy and number of spot welds present. Also by χ2 analysis, the degree of calcar atrophy was not significantly different between groups. The mean VAS score for pain at 24 months was 12.5 for the control and 12.1 for the treatment group. No significant differences were seen in any of the clinical categories of the SICOT Scale over the 24-month interval. Conclusion The objective of TCP-coating — to increase the rate and amount of bony ingrowth while reducing the rate of calcar resorption in non-cemented THA

  14. [Trochanteric femoral fractures].

    PubMed

    Douša, P; Čech, O; Weissinger, M; Džupa, V

    2013-01-01

    At the present time proximal femoral fractures account for 30% of all fractures referred to hospitals for treatment. Our population is ageing, the proportion of patients with post-menopausal or senile osteoporosis is increasing and therefore the number of proximal femoral fractures requiring urgent treatment is growing too. In the age category of 50 years and older, the incidence of these fractures has increased exponentially. Our department serves as a trauma centre for half of Prague and part of the Central Bohemia Region with a population of 1 150 000. Prague in particular has a high number of elderly citizens. Our experience is based on extensive clinical data obtained from the Register of Proximal Femoral Fractures established in 1997. During 14 years, 4280 patients, 3112 women and 1168 men, were admitted to our department for treatment of proximal femoral fractures. All patients were followed up until healing or development of complications. In the group under study, 82% were patients older than 70 years; 72% of those requiring surgery were in their seventies and eighties. Men were significantly younger than women (p<0.001) and represented 30% of the group. The fractures were 2.3-times more frequent in women than in men. In the category under 60 years, men significantly outnumbered women (p<0.001). The patients with pertrochanteric fractures were, on the average, eight years older than the patients with intertrochanteric fractures, which is a significant difference (p<0.001). The mortality rate within a year of injury was about 30%. Trochanteric fractures accounted for 54.7% and femoral neck fractures for 45.3% of all fractures. The inter-annual increase was 5.9%, with more trochanteric than femoral neck fractures. There was a non-significant decrease in intertrochanteric (AO 31-A3) fractures. On the other hand, the number of pertrochanteric (AO 31-A1+2) fractures increased significantly (p<0.001). A total of 1 394 fractures were treated with a proximal

  15. Total Hip Arthroplasty around the Inception of the Interface Bioactive Bone Cement Technique

    PubMed Central

    Oonishi, Hiroyuki; Kawahara, Ikuo

    2016-01-01

    Background To augment cement-bone fixation, Dr. Hironobu Oonishi attempted additional physicochemical bonding through interposition of osteoconductive crystal hydroxyapatite (HA) granules at the cement-bone interface in 1982. He first used the interface bioactive bone cement (IBBC) technique in 12 selected patients (12 hips) in 1982 (first stage) and followed them for 2 years. In 1985, the technique was applied in 25 total hip arthroplasty (THA) patients (second stage) and the effects were investigated by comparing the side with the IBBC technique and the other side without the IBBC technique. He has employed this technique in all THA patients since 1987 (third stage). Methods In the IBBC technique, HA granules (2 to 3 g) were smeared on the bone surface just before the acetabular and femoral components were cemented. In the first stage, 12 hips were operated using the IBBC technique in 1982. In the second stage, THA was performed without the IBBC technique on one side and with the IBBC technique on the other side within 1 year in 25 patients. In the third stage, THA was performed with the IBBC technique in 285 hips in 1987. Results In the first stage patients, implant loosening was not detected at 30 years after operation. In the second stage patients, revision was required in 7 hips without the IBBC technique due to cup loosening (5 hips) and stem loosening (2 hips), whereas no hip was revised after THA with the IBBC technique at 26 years after operation. In the third stage patients, the incidence of radiolucent lines and osteolysis was very few at 25 years after operation. Conclusions The long-term follow-up of THA performed around the inception of the IBBC technique has revealed low incidences of radiolucent lines, osteolysis, and revision surgery. PMID:27583104

  16. Influence of the tibial stem design on bone density after cemented total knee arthroplasty: a prospective seven-year follow-up study.

    PubMed

    Hernandez-Vaquero, Daniel; Garcia-Sandoval, Manuel A; Fernandez-Carreira, Jose M; Gava, Richard

    2008-02-01

    We prospectively measured the changes in bone mineral density (BMD) in the proximal tibia of 20 total knee arthroplasties, ten with cruciform stems and ten with cylindrical stems. The measurements were made one, four and seven years after surgery. We observed a uniform density decrease in three regions of interest from one to seven years of follow-up. Cylindrical stems showed an asymmetrical density decrease between the three regions of interest, with no change in the central region, a slight decrease in the lateral region, and large decrease in the medial region. Multivariate analysis with general linear model showed the stem type factor as statistically significant for medial region of interest (p = 0.006). The cylindrical stem produces heterogeneous BMD changes under the tibial platform in knee arthroplasties, and this could be a potential risk factor for asymmetrical subsidence of this component. PMID:17115154

  17. Effect of cement fill ratio in loosening of hip implants

    PubMed Central

    Gunn, Elizabeth; Gundapaneni, Dinesh; Goswami, Tarun

    2012-01-01

    Femoral loosening is one of the most prevalent causes of revision orthopedic surgeries. Cement mantle thickness has been directly correlated with femoral loosening. If the mantle is too thick, there is an increased risk of radiolucent lines and inconsistent densities. Also, the more bone that is reamed out during the procedure can lead to instability, especially if the quality of the bone is compromised due to osteoporosis. Too thin of a mantle can lead to a higher probability for cement fracture, loosening the prosthetic even further. This study has shown that there is an ideal thickness range between two to five that should be kept. From radiographic images one can measure the thickness of the cement mantle showing the loosening characteristics. PMID:23507806

  18. Effect of strontium-containing hydroxyapatite bone cement on bone remodeling following hip replacement.

    PubMed

    Ni, Guo X; Lin, Jian H; Chiu, Peter K Y; Li, Zhao Y; Lu, William W

    2010-01-01

    It is uncertain whether the use of bioactive bone cement has any beneficial effect on local bone adaptation following hip replacement. In this study, twelve goats underwent cemented hip hemiarthroplasty unilaterally, with either PMMA bone cement or strontium-containing hydroxyapatite (Sr-HA) bioactive bone cement. Nine months later, the femoral cortical bones at different levels were analyzed by microhardness testing and micro-CT scanning. Extensive bone remodeling was found at proximal and mid-levels in both PMMA and Sr-HA groups. However, with regard to the differences of bone mineral density, cortical bone area and bone hardness between implanted and non-implanted femur, less decreases were found in Sr-HA group than PMMA group at proximal and mid-levels, and significant differences were shown for bone area and hardness at proximal level. The results suggested that the use of Sr-HA cement might alleviate femoral bone remodeling after hip replacement. PMID:19728042

  19. Spontaneous modular femoral head dissociation complicating total hip arthroplasty.

    PubMed

    Talmo, Carl T; Sharp, Kinzie G; Malinowska, Magdalena; Bono, James V; Ward, Daniel M; LaReau, Justin

    2014-06-01

    Modular femoral heads have been used successfully for many years in total hip arthroplasty. Few complications have been reported for the modular Morse taper connection between the femoral head and trunnion of the stem in metal-on-polyethylene bearings. Although there has always been some concern over the potential for fretting, corrosion, and generation of particulate debris at the modular junction, this was not considered a significant clinical problem. More recently, concern has increased because fretting and corrosive debris have resulted in rare cases of pain, adverse local tissue reaction, pseudotumor, and osteolysis. Larger femoral heads, which have gained popularity in total hip arthroplasty, are suspected to increase the potential for local and systemic complications of fretting, corrosion, and generation of metal ions because of greater torque at the modular junction. A less common complication is dissociation of the modular femoral heads. Morse taper dissociation has been reported in the literature, mainly in association with a traumatic event, such as closed reduction of a dislocation or fatigue fracture of the femoral neck of a prosthesis. This report describes 3 cases of spontaneous dissociation of the modular prosthetic femoral head from the trunnion of the same tapered titanium stem because of fretting and wear of the Morse taper in a metal-on-polyethylene bearing. Continued clinical and scientific research on Morse taper junctions is warranted to identify and prioritize implant and surgical factors that lead to this and other types of trunnion failure to minimize complications associated with Morse taper junctions as hip implants and surgical techniques continue to evolve. PMID:24972443

  20. Lunar cement

    NASA Technical Reports Server (NTRS)

    Agosto, William N.

    1992-01-01

    With the exception of water, the major oxide constituents of terrestrial cements are present at all nine lunar sites from which samples have been returned. However, with the exception of relatively rare cristobalite, the lunar oxides are not present as individual phases but are combined in silicates and in mixed oxides. Lime (CaO) is most abundant on the Moon in the plagioclase (CaAl2Si2O8) of highland anorthosites. It may be possible to enrich the lime content of anorthite to levels like those of Portland cement by pyrolyzing it with lunar-derived phosphate. The phosphate consumed in such a reaction can be regenerated by reacting the phosphorus product with lunar augite pyroxenes at elevated temperatures. Other possible sources of lunar phosphate and other oxides are discussed.

  1. The biomechanical effect of bone quality and fracture topography on locking plate fixation in periprosthetic femoral fractures.

    PubMed

    Leonidou, Andreas; Moazen, Mehran; Lepetsos, Panagiotis; Graham, Simon M; Macheras, George A; Tsiridis, Eleftherios

    2015-02-01

    Optimal management of periprosthetic femoral fractures (PFF) around a well fixed prosthesis (Vancouver B1) remains controversial as adequate fixation needs to be achieved without compromising the stability of the prosthesis. The aim of this study was to highlight the effect of bone quality i.e. canal thickness ratio (CTR), and fracture topography i.e. fracture angle and its position in relation to the stem, on the biomechanics of a locking plate for a Vancouver B1 fracture. A previously corroborated simplified finite element model of a femur with a cemented total hip replacement stem was used in this study. Canal thickness ratio (CTR) and fracture topography were altered in several models and the effect of these variations on the von Mises stress on the locking plate as well as the fracture displacement was studied. Increasing the CTR led to reduction of the von Mises stress on the locking plate as well as the fracture movement. In respect to the fracture angle with the medial cortex, it was shown that acute angles resulted in lower von Mises stress on the plate as opposed to obtuse angles. Furthermore, acute fracture angles resulted in lower fracture displacement compared to the other fractures considered here. Fractures around the tip of the stem had the same biomechanical effect on the locking plate. However, fractures more distal to the stem led to subsequent increase of stress, strain, and fracture displacement. Results highlight that in good bone quality and acute fracture angles, single locking plate fixation is perhaps an appropriate management method. On the contrary, for poor bone quality and obtuse fracture angles alternative management methods might be required as the fixation might be under higher risk of failure. Clinical studies for the management of PFF are required to further support our findings. PMID:25467710

  2. Sculpting with Cement.

    ERIC Educational Resources Information Center

    Olson, Lynn

    1983-01-01

    Cement offers many creative possibilities for school art programs. Instructions are given for sculpting with fiber-cement and sand-cement, as well as for finishing processes and the addition of color. Safety is stressed. (IS)

  3. Finite element analysis on longitudinal and radial functionally graded femoral prosthesis.

    PubMed

    Oshkour, Azim Ataollahi; Abu Osman, N A; Davoodi, M M; Yau, Y H; Tarlochan, F; Wan Abas, W A B; Bayat, M

    2013-12-01

    This study focused on developing a 3D finite element model of functionally graded femoral prostheses to decrease stress shielding and to improve total hip replacement performance. The mechanical properties of the modeled functionally graded femoral prostheses were adjusted in the sagittal and transverse planes by changing the volume fraction gradient exponent. Prostheses with material changes in the sagittal and transverse planes were considered longitudinal and radial prostheses, respectively. The effects of cemented and noncemented implantation methods were also considered in this study. Strain energy and von Mises stresses were determined at the femoral proximal metaphysis and interfaces of the implanted femur components, respectively. Results demonstrated that the strain energy increased proportionally with increasing volume fraction gradient exponent, whereas the interface stresses decreased on the prostheses surfaces. A limited increase was also observed at the surfaces of the bone and cement. The periprosthetic femur with a noncemented prosthesis exhibited higher strain energy than with a cemented prosthesis. Radial prostheses implantation displayed more strain energy than longitudinal prostheses implantation in the femoral proximal part. Functionally graded materials also increased strain energy and exhibited promising potentials as substitutes of conventional materials to decrease stress shielding and to enhance total hip replacement lifespan. PMID:23922316

  4. Modern cementing techniques. An experimental study of vacuum insertion of bone cement.

    PubMed

    Draenert, K

    1989-01-01

    The results of these experiments show that an increase in the intramedullary pressure (IMP) can lead to embolization of bone marrow contents via the venous drainage system along the linea aspera. A vacuum applied distally to the medullary canal is very effective for filling the diaphyseal tube with cement. The cancellous bone honeycombs of the proximal metaphysis, however, can only be filled if the bone sponge is tunneled at the level of the femoral calcar; a proximal vacuum then yields filling of the cancellous bone framework with bone cement. In order to fill the weight-bearing spongious framework of the pelvic bone with cement, the acetabular cavity should be sealed with a rubber ring and vacuum applied proximo-laterally to the ilium, thereby giving an extremely high suction pressure. PMID:2690560

  5. An integrated CAD/CAM/robotic milling method for custom cementless femoral prostheses.

    PubMed

    Wen-ming, Xi; Ai-min, Wang; Qi, Wu; Chang-hua, Liu; Jian-fei, Zhu; Fang-fang, Xia

    2015-09-01

    Aseptic loosening is the primary cause of cementless femoral prosthesis failure and is related to the primary stability of the cementless femoral prosthesis in the femoral cavity. The primary stability affects both the osseointegration and the long-term stability of cementless femoral prostheses. A custom cementless femoral prosthesis can improve the fit and fill of the prosthesis in the femoral cavity and decrease the micromotion of the proximal prosthesis such that the primary stability of the custom prosthesis can be improved, and osseointegration of the proximal prosthesis is achieved. These results will help to achieve long-term stability in total hip arthroplasty (THA). In this paper, we introduce an integrated CAD/CAM/robotic method of milling custom cementless femoral prostheses. The 3D reconstruction model uses femoral CT images and 3D design software to design a CAD model of the custom prosthesis. After the transformation matrices between two units of the robotic system are calibrated, consistency between the CAM software and the robotic system can be achieved, and errors in the robotic milling can be limited. According to the CAD model of the custom prosthesis, the positions of the robotic tool points are produced by the CAM software of the CNC machine. The normal vector of the three adjacent robotic tool point positions determines the pose of the robotic tool point. In conclusion, the fit rate of custom pig femur stems in the femoral cavities was 90.84%. After custom femoral prostheses were inserted into the femoral cavities, the maximum gaps between the prostheses and the cavities measured less than 1 mm at the diaphysis and 1.3 mm at the metaphysis. PMID:26210779

  6. [Pathogenesis of atypical femoral fracture].

    PubMed

    Iwata, Ken; Mashiba, Tasuku

    2016-01-01

    We demonstrated microdamage accumulation in the fracture sites in the patients of subtrochanteric atypical femoral fracture with long term bisphosphonate therapy and of incomplete shaft fracture of lateral femoral bowing without bisphosphonate therapy. Based on these findings, pathogenesis of atypical femoral fracture is revealed stress fracture caused by accumulation of microdamages between distal to the lesser trochanter and proximal to the supracondylar flare in the femur in association with severely suppressed bone turnover and/or abnormal lower limb alignment, that causes stress concentration on the lateral side cortex of the femur. PMID:26728533

  7. Femoral approach to lead extraction.

    PubMed

    Mulpuru, Siva K; Hayes, David L; Osborn, Michael J; Asirvatham, Samuel J

    2015-03-01

    Laser and radiofrequency energy-assisted lead extraction has greatly facilitated this complex procedure. Although success rates are high, in some instances alternate methods of extraction are required. In this review, we discuss techniques for femoral extraction of implanted leads and retained fragments. The major tools available, including commonly used snares and delivery tools, are discussed. We briefly describe combined internal jugular and femoral venous extraction approaches, as well as complimentary utilization of more than one technique via the femoral vein. Animated and procedural sequences are included to help the reader visualize the key components of these techniques. PMID:25311643

  8. Comparison of cementing techniques of the tibial component in total knee replacement

    PubMed Central

    Li, Ming Guo; Wood, David; Nivbrant, Bo

    2008-01-01

    A few studies have shown that cementing the stem enhances fixation of the tibial baseplate in total knee replacement (TKR). Even the horizontal technique has been shown to provide good fixation. We used radiostereometry to study migration of the tibial component in 30 knees operated with Profix TKR. The knees were randomised for either complete (both under the baseplate and around the stem) or horizontal (only under the baseplate) cementing of the tibial component. At two years the tibial baseplate rotated externally a median of 0.18° in the uncemented stem group and internally a median of 0.23° in the cemented stem group. The tibial baseplate subsided 0.14 mm in the cemented stem group, and no translation was seen in the uncemented stem group. The differences in migration were small and probably without clinical significance. The findings do not favour either of the cementing techniques in TKR. PMID:18704414

  9. Comparison of cementing techniques of the tibial component in total knee replacement.

    PubMed

    Saari, Tuuli; Li, Ming Guo; Wood, David; Nivbrant, Bo

    2009-10-01

    A few studies have shown that cementing the stem enhances fixation of the tibial baseplate in total knee replacement (TKR). Even the horizontal technique has been shown to provide good fixation. We used radiostereometry to study migration of the tibial component in 30 knees operated with Profix TKR. The knees were randomised for either complete (both under the baseplate and around the stem) or horizontal (only under the baseplate) cementing of the tibial component. At two years the tibial baseplate rotated externally a median of 0.18 degrees in the uncemented stem group and internally a median of 0.23 degrees in the cemented stem group. The tibial baseplate subsided 0.14 mm in the cemented stem group, and no translation was seen in the uncemented stem group. The differences in migration were small and probably without clinical significance. The findings do not favour either of the cementing techniques in TKR. PMID:18704414

  10. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2002-07-30

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report includes results from laboratory testing of ULHS systems along with other lightweight cement systems, including foamed and sodium silicate slurries. During this project quarter, a comparison study of the three cement systems examined the effect that cement drillout has on the three cement systems. Testing to determine the effect of pressure cycling on the shear bond properties of the cement systems was also conducted. This report discusses testing that was performed to analyze the alkali-silica reactivity of ULHS in cement slurries.

  11. Bone scintigraphy in slipped capital femoral epiphysis

    SciTech Connect

    Gelfand, M.J.; Strife, J.L.; Graham, E.J.; Crawford, A.H.

    1983-12-01

    Tc-/sub 99m/ diphosphonate bone scans were performed on 11 children with slipped capital femoral epiphysis. On pinhole hip images, seven hips in seven patients had increased radionuclide uptake in the physis and adjacent proximal femoral metaphysis where the slip had occurred. Three hips in three patients had decreased radionuclide uptake in the femoral head on the side of the slipped epiphysis, indicating compromise of the femoral head blood supply. Three or more months following internal fixation, three children had scintigraphy that showed loss of the usual focal uptake in the physis and adjacent proximal femoral metaphysis. Bone scintigraphy in pediatric patients with slipped capital femoral epiphysis is valuable in defining the metabolic status of the femoral head. Absence of radiopharmaceutical uptake in the affected femoral head indicates that the femoral head is at risk for development of radiographic changes associated with aseptic necrosis.

  12. A complication during femoral broaching in total hip arthroplasty: a case report.

    PubMed

    Waldstein, Wenzel; Boettner, Friedrich

    2013-01-01

    Press-fit component fixation is one of the primary goals in uncemented total hip arthroplasty. When aiming at proximal load transfer, the stem size has to be selected with regard to the shape of the proximal femoral canal. This can be challenging in patients with 'champagne flute' femurs with a relatively narrow diaphysis, especially when a long stem femoral component is used. The present case report describes a complication during femoral broaching for a primary uncemented femoral component. Because of the narrow diaphysis, the distal portion of the broach got caught in the narrow canal and it became impossible to remove the broach with conventional techniques. Via a second distal incision, the femur was split from the distal tip of the broach to approximately 5 cm distal of the femoral neck cut along the posterior aspects of the femur. This loosened the broach enough to allow for an uncomplicated removal. The longitudinal split was secured with cables before a similar size primary implant was press fitted into the femoral canal. PMID:23961301

  13. USE OF CORTICAL STRUCTURAL HOMOLOGOUS BONE GRAFT IN FEMORAL RECONSTRUCTIVE SURGERY

    PubMed Central

    Roos, Milton Valdomiro; Roos, Bruno Dutra; Giora, Taís Stedile Busin; Taglietti, Thiago Martins

    2015-01-01

    To perform a clinical and radiographic assessment of patients undergoing surgical treatment using a cortical structural homologous bone graft for femoral reconstruction following mechanical failure of total hip arthroplasty and periprosthetic fractures. Methods: A retrospective study was conducted on 27 patients who underwent surgical treatment for femoral reconstruction following mechanical failure of total hip arthroplasty (12 cases) and periprosthetic fractures (15 cases), using a cortical structural homologous bone graft and cemented implants, between June 1999 and February 2008. Of these, 21 fulfilled all the criteria required for this study. The patients underwent pre and postoperative clinical assessments using the Harris Hip Score. Preoperative, immediate postoperative and late postoperative radiographs were also evaluated, with comparisons of fracture consolidation, radiographic signs of graft consolidation, changes to the bone stock and femoral bone quality, and femoral alignment. Results: Nine patients (42.9%) underwent femoral reconstruction following mechanical failure of total hip arthroplasty and 12 cases (57.1%) underwent femoral reconstruction following periprosthetic fracture. Regarding the postoperative clinical classification, the results were considered satisfactory in 85.7% of the cases and unsatisfactory in 14.3%. Radiographic signs of graft consolidation were seen in all cases. There was an increase in bone stock in 90.5% of the hip reconstructions, as measured by the cortical index. Furthermore, the changes to femoral bone quality were considered good in 66.7% of the cases. Conclusion: The use of cortical structural homologous bone grafts for both femoral reconstructive surgery on total hip arthroplasty and periprosthetic fractures is a good treatment option for selected cases, enabling satisfactory clinical and radiographic results. PMID:27026955

  14. In vivo performance of a reduced-modulus bone cement

    NASA Astrophysics Data System (ADS)

    Forehand, Brett Ramsey

    Total joint replacement has become one of the most common procedures in the area of orthopedics and is often the solution in patients with diseased or injured hip joints. Component loosening is a significant problem and is primarily caused by bone resorption at the bone-cement interface in cemented implants. It is our hypothesis that localized shear stresses are responsible for the resorption. It was previously shown analytically that local stresses at the interface could be reduced by using a cement of lower modulus. A new reduced modulus cement, polybutyl methylmethacrylate (PBMMA), was developed to test the hypothesis. PBMMA was formulated to exist as polybutyl methacrylate filler in a polymethyl methacrylate matrix. The success of PBMMA cement is based largely on the fact that the polybutyl component of the cement will be in the rubbery state at body temperature. In vitro characterization of the cement was undertaken previously and demonstrated a modulus of approximately one-eighth that of conventional bone cement, polymethyl methacrylate (PMMA) and increased fracture toughness. The purpose of this experiment was to perform an in vivo comparison of the two cements. A sheep model was selected. Total hip arthroplasty was performed on 50 ewes using either PBMMA or PMMA. Radiographs were taken at 6 month intervals. At one year, the contralateral femur of each sheep was implanted so that each animal served as its own control, and the animals were sacrificed. The stiffness of the bone-cement interface of the femoral component within the femur was assessed by applying a torque to the femoral component and demonstrated a significant difference in loosening between the cements when the specimens were tested in external rotation (p < 0.007). Evaluation of the mechanical data also suggests that the PBMMA sheep had a greater amount of loosening for each subject, 59% versus 4% for standard PMMA. A radiographic analysis demonstrated more signs of loosening in the PMMA series

  15. Arthroscopically confirmed femoral button deployment.

    PubMed

    Sonnery-Cottet, Bertrand; Rezende, Fernando C; Martins Neto, Ayrton; Fayard, Jean M; Thaunat, Mathieu; Kader, Deiary F

    2014-06-01

    The anterior cruciate ligament TightRope RT (Arthrex, Naples, FL) is a graft suspension device for cruciate ligament reconstruction. It is an adjustable-length graft loop cortical fixation device designed to eliminate the requirement for loop length calculation and to facilitate complete graft fill of short femoral sockets that are common with anatomic anterior cruciate ligament placement. The adjustable loop length means "one size fits all," thus removing the need for multiple implant sizes and allowing graft tensioning even after fixation. However, the device has been associated with the same complications that have been described with EndoButton (Smith & Nephew Endoscopy, Andover, MA) fixation. The button of the TightRope RT may remain in the femoral tunnel rather than flipping outside of the tunnel to rest on the lateral femoral cortex, or it may become jammed inside the femoral canal. Conversely, the button may be pulled too far off the femoral cortex into the overlying soft tissue and flip in the substance of the vastus lateralis. We describe a new and simple arthroscopic technique to directly visualize the deployment and seating of the TightRope button on the lateral cortex of the femur to avoid all the aforementioned complications. PMID:25126492

  16. Revision total hip replacement using the cement-in-cement technique for the acetabular component: technique and results for 60 hips.

    PubMed

    Brogan, K; Charity, J; Sheeraz, A; Whitehouse, S L; Timperley, A J; Howell, J R; Hubble, M J W

    2012-11-01

    The technique of femoral cement-in-cement revision is well established, but there are no previous series reporting its use on the acetabular side at the time of revision total hip replacement. We describe the technique and report the outcome of 60 consecutive acetabular cement-in-cement revisions in 59 patients at a mean follow-up of 8.5 years (5 to 12). All had a radiologically and clinically well-fixed acetabular cement mantle at the time of revision. During the follow-up 29 patients died, but no hips were lost to follow-up. The two most common indications for acetabular revision were recurrent dislocation (46, 77%) and to complement femoral revision (12, 20%). Of the 60 hips, there were two cases of aseptic loosening of the acetabular component (3.3%) requiring re-revision. No other hip was clinically or radiologically loose (96.7%) at the latest follow-up. One hip was re-revised for infection, four for recurrent dislocation and one for disarticulation of a constrained component. At five years the Kaplan-Meier survival rate was 100% for aseptic loosening and 92.2% (95% CI 84.8 to 99.6), with revision for any cause as the endpoint. These results support the use of cement-in-cement revision on the acetabular side in appropriate cases. Theoretical advantages include preservation of bone stock, reduced operating time, reduced risk of complications and durable fixation. PMID:23109626

  17. Porous Surface Modified Bioactive Bone Cement for Enhanced Bone Bonding

    PubMed Central

    Huang, Li; Dong, Jingjing; Guo, Dagang; Mao, Mengmeng; Kong, Liang; Li, Yang; Wu, Zixiang; Lei, Wei

    2012-01-01

    Background Polymethylmethacrylate bone cement cannot provide an adhesive chemical bonding to form a stable cement-bone interface. Bioactive bone cements show bone bonding ability, but their clinical application is limited because bone resorption is observed after implantation. Porous polymethylmethacrylate can be achieved with the addition of carboxymethylcellulose, alginate and gelatin microparticles to promote bone ingrowth, but the mechanical properties are too low to be used in orthopedic applications. Bone ingrowth into cement could decrease the possibility of bone resorption and promote the formation of a stable interface. However, scarce literature is reported on bioactive bone cements that allow bone ingrowth. In this paper, we reported a porous surface modified bioactive bone cement with desired mechanical properties, which could allow for bone ingrowth. Materials and Methods The porous surface modified bioactive bone cement was evaluated to determine its handling characteristics, mechanical properties and behavior in a simulated body fluid. The in vitro cellular responses of the samples were also investigated in terms of cell attachment, proliferation, and osteoblastic differentiation. Furthermore, bone ingrowth was examined in a rabbit femoral condyle defect model by using micro-CT imaging and histological analysis. The strength of the implant–bone interface was also investigated by push-out tests. Results The modified bone cement with a low content of bioactive fillers resulted in proper handling characteristics and adequate mechanical properties, but slightly affected its bioactivity. Moreover, the degree of attachment, proliferation and osteogenic differentiation of preosteoblast cells was also increased. The results of the push-out test revealed that higher interfacial bonding strength was achieved with the modified bone cement because of the formation of the apatite layer and the osseointegration after implantation in the bony defect. Conclusions

  18. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2003-10-31

    The objective of this project is to develop an improved ultra- lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report discusses testing that was performed for analyzing the alkali-silica reactivity of ULHS in cement slurries.

  19. Tibial hemimelia and femoral bifurcation.

    PubMed

    Ugras, Ali Akin; Sungur, Ibrahim; Akyildiz, Mustafa Fehmi; Ercin, Ersin

    2010-02-01

    Femoral bifurcation and tibial agenesis are rare anomalies and have been described in both the Gollop-Wolfgang complex and tibial agenesis-ectrodactyly syndrome. This article presents a case of Gollop-Wolfgang complex without hand ectrodactyly. Tibial agenesis-ectrodactyly syndrome and Gollop-Wolfgang complex are variants of tibial field defect, which includes distal femoral duplication, tibial aplasia, oligo-ectrodactylous toe defects, and preaxial polydactyly, occasionally associated with hand ectrodactyly.This article describes the case of a patient with bilateral tibial hemimelia and left femoral bifurcation. The proximal tibial anlage had not been identified in the patient's left leg. After failed fibular transfer procedure, the knee was disarticulated. The other leg was treated with tibiofibular synostosis and centralization of fibula to os calcis. At 7-year follow-up, the patient ambulates with an above-knee prosthesis and uses an orthopedic boot for ankle stability.In patients with a congenital absence of the tibia, accurate diagnosis is of the utmost importance in planning future treatment. In the absence of proximal tibial anlage, especially in patients with femoral bifurcation, the knee should be disarticulated. Tibiofibular synostosis is a good choice in the presence of a proximal tibial anlage and good quadriceps function. PMID:20192156

  20. Femoral head cartilage disarticulation disorder

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Femoral head cartilage disarticulation disorder and necrosis is a major skeletal problem in broiler breeders since they are maintained for a long time in the farm. The etiology of this disease is not well understood. A field study was conducted to understand the basis of this metabolic disease. Six ...

  1. A sliding stem in revision total knee arthroplasty provides stability and reduces stress shielding

    PubMed Central

    van Loon, Corné J M; de Waal Malefijt, Maarten C; van Kampen, Albert; Verdonschot, Nico

    2010-01-01

    Background and purpose In the reconstruction of unicondylar femoral bone defects with morselized bone grafts in revision total knee arthroplasty, a stem extension appears to be critical to obtain adequate mechanical stability. Whether stability is still assured by this reconstruction technique in bicondylar defects has not been assessed. The disadvantage of relatively stiff stem extensions is that bone resorption is promoted due to stress shielding. We therefore designed a stem that would permit axial sliding movements of the articulating part relative to the intramedullary stem. Methods This stem was used in the reconstruction with impaction bone grafting (IBG) of 5 synthetic distal femora with a bicondylar defect. A cyclically axial load was applied to the prosthetic condyles to assess the stability of the reconstruction. Radiostereometry was used to determine the migrations of the femoral component with a rigidly connected stem, a sliding stem, and no stem extension. Results We found a stable reconstruction of the bicondylar femoral defects with IBG in the case of a rigidly connected stem. After disconnecting the stem, the femoral component showed substantially more migrations. With a sliding stem, rotational migrations were similar to those of a rigidly connected stem. However, the sliding stem allowed proximal migration of the condylar component, thereby compressing the IBG. Interpretation The presence of a functional stem extension is important for the stability of a bicondylar reconstruction. A sliding stem provides adequate stability, while stress shielding is reduced because compressive contact forces are still transmitted to the distal femoral bone. PMID:20450422

  2. Photoelastic and thermoelastic measurement of stress on the proximal femur before and after implantation of a hip prosthesis with retention of the femoral neck.

    PubMed

    Refior, Jans Jürgen; Schidlo, Christoph; Plitz, Wolfgang; Heining, Sandro

    2002-05-01

    This study demonstrated the improved medial support and the transfer of load onto the retained neck of the femur using seven fresh frozen femurs. Results confirm the reliability of the thermoelastic stress analysis method, which is comparable to the photoelastic surface coating method, but with greater sensitivity. The loading pattern after stem implantation shows a homogeneous transfer of force onto the preserved femoral neck. After femoral neck removal, an inhomogeneous increase of the intertrochanteric compression loading was observed. Therefore, improved biomechanical conditions are created for a permanently stable implantation of stem prostheses with retention of the femoral neck. PMID:12046909

  3. Anterior Hip Fracture Dislocation with Intrapelvic Retention of the Femoral Head and Ureter Fistula

    PubMed Central

    Patrascanu, Calin; Cibu, Dan

    2014-01-01

    Introduction: The anterior dislocation of the hip represents only a small percentage of all hip dislocations: 85% are posterior. Most commonly associated with this dislocation is a fracture of the femoral head and, in rare cases, a femoral neck fracture. We have found in literature no report of an anterior dislocation of the hip associated with femoral neck fracture, pelvic retention of the head and ureteral fistula. We report such a case of a 68 year old male. Case Report: A 68 year old male was presented to our attention, following a severe injury of the hip when falling from a high bridge, with severe pain in the hip and a clinical aspect of femoral neck fracture. The X-ray confirmed the femoral neck fracture but following an anterior dislocation with the head retained into the pelvis. The patient also had hematuria. An Austin Moore prosthesis was implanted for the femoral neck fracture and the head was extracted by the urologist by a new abdominal incision. Urological evaluation revealed a fistula of the ureter, treated by an internal drainage for three months. One month later the Moore prosthesis was extracted and the patient had a Girldestone hip for 5 months. Revision with a Muller cemented prosthesis had a normal evolution. Conclusion: The anterior fracture dislocation of the hip with pelvic retention of the femoral head and ureteral fistula is a rare condition resulting from high energy trauma. A multidisciplinary team is necessary to diagnose and treat fracture and soft tissue lesions. Early diagnosis and treatment is necessary to avoid septic complications. PMID:27298980

  4. Cemented total hip prosthesis: Radiographic and scintigraphic evaluation

    SciTech Connect

    Aliabadi, P.; Tumeh, S.S.; Weissman, B.N.; McNeil, B.J. )

    1989-10-01

    Conventional radiographs, technetium-99m bone scans, and gallium-67 scans were reviewed in 44 patients who had undergone cemented total hip joint replacement and were imaged because of suspicion of prosthesis loosening or infection. A complete radiolucent line of 2 mm or wider along the bone-cement interface or metal-cement lucency on conventional radiographs was used as the criterion for prosthetic loosening with or without infection and proved to be 54% sensitive and 96% specific. Scintigraphic criteria for prosthetic loosening were increased focal uptake of the radiopharmaceutical for the femoral component and increased focal or diffuse uptake for the acetabular component. For bone scintigraphy, sensitivity was 73% and specificity was 96%. Combining the results of conventional radiographs and bone scans increased sensitivity to 84% and decreased specificity to 92% for the diagnosis of loosening, infection, or both. The study also showed that Ga-67 scintigraphy has a low sensitivity for the detection of infection.

  5. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2001-04-15

    The objective of this project is to develop an improved ultra-lightweight cement using ultralight hollow glass spheres (ULHS). Work reported herein addresses Task 1: Assess Ultra-Lightweight Cementing Problems and Task 3: Test Ultra-Lightweight Cements. Results reported this quarter include a review and summary of Halliburton Energy Services (HES) and BJ Services historical performance data for lightweight cement applications. These data are analyzed and compared to ULHS cement and foamed cement performances. Similar data is expected from Schlumberger, and an analysis of this data will be completed in the following phases of the project. Quality control testing of materials used to formulate ULHS cements in the laboratory was completed to establish baseline material performance standards. A testing protocol was developed employing standard procedures as well as procedures tailored to evaluate ULHS and foamed cement. This protocol is presented and discussed. Results of further testing of ULHS cements are presented along with an analysis to establish cement performance design criteria to be used during the remainder of the project. Finally, a list of relevant literature on lightweight cement performance is compiled for review during the next quarter.

  6. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2001-07-18

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). Work reported herein addresses Task 1: Assess Ultra-Lightweight Cementing Issues, Task 2: Review Russian Ultra-Lightweight Cement Literature, Task 3: Test Ultra-Lightweight Cements, and Task 8: Develop Field ULHS Cement Blending and Mixing Techniques. Results reported this quarter include: preliminary findings from a literature review focusing on problems associated with ultra-lightweight cements; summary of pertinent information from Russian ultra-lightweight cement literature review; laboratory tests comparing ULHS slurries to foamed slurries and sodium silicate slurries for two different applications; and initial laboratory studies with ULHS in preparation for a field job.

  7. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2002-04-29

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report includes results from laboratory testing of ULHS systems along with other lightweight cement systems, including foamed and sodium silicate slurries. During this project quarter, comparison studies of the three cement systems examined several properties: tensile strength, Young's modulus, and shear bond. Testing to determine the effect of temperature cycling on the shear bond properties of the cement systems was also conducted. In addition, the stress-strain behavior of the cement types was studied. This report discusses a software program that is being developed to help design ULHS cements and foamed cements.

  8. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2002-10-31

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report includes results from laboratory testing of ULHS systems along with other lightweight cement systems, including foamed and sodium silicate slurries. During this project quarter, a comparison study of the three cement systems examined the effect that cement drillout has on the three cement systems. Testing to determine the effect of pressure cycling on the shear bond properties of the cement systems was also conducted. This report discusses testing that will be performed for analyzing the alkali-silica reactivity of ULHS in cement slurries, as well as the results of Field Tests 1 and 2.

  9. Osteolytic changes around biodegradable cement restrictors in hip surgery.

    PubMed

    Erschbamer, Matthias; Zdravkovic, Vilijam; Erhardt, Johannes; Öhlschlegel, Christian; Grob, Karl

    2016-06-01

    Background and purpose - Biodegradable cement restrictors are widely used in hip arthroplasty. Like others, we observed osteolytic reactions associated with a specific cement restrictor (SynPlug; made of PolyActive) and reviewed our patients. Patients and methods - We identified 703 patients with suitable radiographs from our database (2007 to 2012) who underwent cemented hip arthroplasty and received a SynPlug biodegradable cement restrictor. We reviewed all available radiographs to determine the incidence, severity, and progression of osteolysis. Mean postoperative follow-up was 1.8 (1-7) years Results - 1 year after implantation, the femoral cortex showed thinning by 12% in the anterior-posterior view and by 8% in the axial view. This had increased to 14% and 12%, respectively, at the latest available follow-up postoperatively (at a mean of 4 years). Cortical thinning of less than 10% was found in 37% of patients, but cortical thinning of 10-30% was found in 56% of patients. In the remaining 7%, a reduction of more than 30% of the original cortical thickness was observed. Interpretation - Osteolytic changes associated with the SynPlug biodegradable bone restrictors are inconsistent and highly variable. While some patients showed increased weakening of the femoral cortex with the potential risk of periprosthetic fracture, in others the degree of osteolysis only increased slightly or stabilized after 2 or more years. Any cortical bone loss after total hip replacement should be avoided, so the use of PolyActive biodegradable cement restrictors should be discontinued. Patients with a PolyActive cement restrictor in place should be followed up closely after surgery. PMID:26905752

  10. Osteolytic changes around biodegradable cement restrictors in hip surgery

    PubMed Central

    Erschbamer, Matthias; Zdravkovic, Vilijam; Erhardt, Johannes; Öhlschlegel, Christian; Grob, Karl

    2016-01-01

    Background and purpose Biodegradable cement restrictors are widely used in hip arthroplasty. Like others, we observed osteolytic reactions associated with a specific cement restrictor (SynPlug; made of PolyActive) and reviewed our patients. Patients and methods We identified 703 patients with suitable radiographs from our database (2007 to 2012) who underwent cemented hip arthroplasty and received a SynPlug biodegradable cement restrictor. We reviewed all available radiographs to determine the incidence, severity, and progression of osteolysis. Mean postoperative follow-up was 1.8 (1–7) years Results 1 year after implantation, the femoral cortex showed thinning by 12% in the anterior-posterior view and by 8% in the axial view. This had increased to 14% and 12%, respectively, at the latest available follow-up postoperatively (at a mean of 4 years). Cortical thinning of less than 10% was found in 37% of patients, but cortical thinning of 10–30% was found in 56% of patients. In the remaining 7%, a reduction of more than 30% of the original cortical thickness was observed. Interpretation Osteolytic changes associated with the SynPlug biodegradable bone restrictors are inconsistent and highly variable. While some patients showed increased weakening of the femoral cortex with the potential risk of periprosthetic fracture, in others the degree of osteolysis only increased slightly or stabilized after 2 or more years. Any cortical bone loss after total hip replacement should be avoided, so the use of PolyActive biodegradable cement restrictors should be discontinued. Patients with a PolyActive cement restrictor in place should be followed up closely after surgery. PMID:26905752