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Sample records for acl deficient knees

  1. Medial collateral ligament insertion site and contact forces in the ACL-deficient knee.

    PubMed

    Ellis, Benjamin J; Lujan, Trevor J; Dalton, Michelle S; Weiss, Jeffrey A

    2006-04-01

    The objectives of this research were to determine the effects of anterior cruciate ligament (ACL) deficiency on medial collateral ligament (MCL) insertion site and contact forces during anterior tibial loading and valgus loading using a combined experimental-finite element (FE) approach. Our hypothesis was that ACL deficiency would increase MCL insertion site forces at the attachments to the tibia and femur and increase contact forces between the MCL and these bones. Six male knees were subjected to varus-valgus and anterior-posterior loading at flexion angles of 0 degrees and 30 degrees. Three-dimensional joint kinematics and MCL strains were recorded during kinematic testing. Following testing, the MCL of each knee was removed to establish a stress-free reference configuration. An FE model of the femur-MCL-tibia complex was constructed for each knee to simulate valgus rotation and anterior translation at 0 degrees and 30 degrees, using subject-specific bone and ligament geometry and joint kinematics. A transversely isotropic hyperelastic material model with average material coefficients taken from a previous study was used to represent the MCL. Subject-specific MCL in situ strain distributions were used in each model. Insertion site and contact forces were determined from the FE analyses. FE predictions were validated by comparing MCL fiber strains to experimental measurements. The subject-specific FE predictions of MCL fiber stretch correlated well with the experimentally measured values (R2 = 0.95). ACL deficiency caused a significant increase in MCL insertion site and contact forces in response to anterior tibial loading. In contrast, ACL deficiency did not significantly increase MCL insertion site and contact forces in response to valgus loading, demonstrating that the ACL is not a restraint to valgus rotation in knees that have an intact MCL. When evaluating valgus laxity in the ACL-deficient knee, increased valgus laxity indicates a compromised MCL. PMID

  2. Magnetic Resonance Imaging of Cartilage Contact and Bound Water in ACL-Deficient and ACL Reconstructed Knees

    PubMed Central

    Baer, Geoffrey Scott; Kaiser, Jarred; Vignos, Michael; Liu, Fang; Smith, Colin Robert; Kijowski, Richard; Thelen, Darryl

    2016-01-01

    Objectives: Osteoarthritis (OA) is common following ACL-reconstructive (ACLR) surgery (6). The cause of early OA is not understood, but theories have focused on osteochondral damage at the time of injury (2) and abnormal joint mechanics following surgical repair (7). In this study, we investigate the inter-relationship of cartilage mechanics and biomarkers of OA in both ACL-deficient (ACLD) and ACLR knees. Our approach employs a novel dynamic MR sequence to measure joint mechanics (3) and the recently developed mcDESPOT to assess regional variations in water bound to proteoglycan (PG) (5). We hypothesize that bound water will be diminished in the cartilage of ACLD knees and, after surgery, will continue to adapt in a manner that reflects altered cartilage loading. This abstract presents initial observations on a cross-section of healthy, ACLD and ACLR knees. Methods: The dominant knees of 8 healthy controls, ACLD knees of 5 patients and ACLR knees of 8 patients were imaged in a 3 T MRI scanner (Table). Controls had no history of pain, injury, or surgery to their knee. Patients had no additional ligament injury and no meniscal damage. ACLD subjects were imaged prior to reconstructive surgery. Femoral and tibial cartilage were segmented from MR images and cartilage thickness was calculated. The mcDESPOT sequence provided a fraction map of water bound to PG (Fpg). Subjects flexed their knee against an inertial load at 0.5 Hz, while a SPGR-VIPR sequence continuously acquired volumetric data. Kinematics were obtained using model tracking of the dynamic images (3). Cartilage was registered to the bone segments for all frames, and contact patterns were characterized by the proximity between surfaces. Spatial representations of tibial cartilage contact, thickness and Fpg were co-registered for each subject. Results: Our initial images suggest lower Fpg values in ACLD knees, primarily on the posterior-lateral tibia. This is also observed in ACLR knees, with additional

  3. High tibial osteotomy in the ACL-deficient knee with medial compartment osteoarthritis.

    PubMed

    Herman, Benjamin V; Giffin, J Robert

    2016-09-01

    High tibial osteotomy (HTO) has traditionally been used to treat varus gonarthrosis in younger, active patients. Varus malalignment increases the risk of progression of medial compartment osteoarthritis and an HTO can be performed to realign the mechanical axis of the lower limb towards the lateral compartment, thereby decreasing contact pressures in the medial compartment. Anterior cruciate ligament (ACL) insufficiency may lead to post-traumatic arthritis due to altered joint loading and associated injuries to the menisci and articular cartilage. Understanding the importance of posterior tibial slope and its role in sagittal knee stability has led to the development of biplane osteotomies designed to flatten the posterior tibial slope in the ACL deficient knee. Altering the alignment in both the sagittal and coronal planes helps improve stability as well as alter the load in the medial compartment. Detailed history, physical exam and radiographic analysis guide treatment decisions in this high demand patient population. Lateral closing wedge (LCW) and medial opening wedge (MOW) HTOs have been performed and their potential advantages and disadvantages have been well described. Given the triangular shape of the proximal tibia, it is imperative that the surgeon pay close attention to the geometry of the osteotomy "gap" when performing MOW HTO to avoid inadvertently increasing the posterior tibial slope. Simultaneous ACL reconstruction may require technique modifications depending on the type of HTO and ACL graft chosen. With appropriate patient selection and good surgical technique, it is reasonable to expect patients to return to activities of daily living and recreational sports without debilitating pain or instability. PMID:27358200

  4. Meniscal tears in the ACL-deficient knee: correlation between meniscal tears and the timing of ACL reconstruction.

    PubMed

    Papastergiou, Stergios G; Koukoulias, Nikolaos E; Mikalef, Petros; Ziogas, Evangelos; Voulgaropoulos, Harilaos

    2007-12-01

    Despite the fact that anterior cruciate ligament reconstruction (ACLR) is a common procedure, no clear guideline regarding the timing of reconstruction has been established. We hypothesized that there is a point in post injury period, after which significant increase in meniscal tears occurs. The purpose of this study was to derive a guideline in order to reduce the rate of secondary meniscal tears in the ACL-deficient knee. A total of 451 patients were retrospectively studied and divided into six groups according to the time from injury to ACLR: (a) 105 patients had undergone ACLR within 1.5 months post injury, (b) 93 patients within 1.5-3 months, (c) 72 patients within fourth to sixth month, (d) 56 patients within seventh to twelfth month, (e) 45 patients within the second year and (f) 80 patients within the third to fifth year. The presence of meniscal tears was noted at the time of ACL reconstruction and then recorded and statistically analysed. Fifty-three (50.5%) patients from group a, 46 (49.5%) from group b, 39 (54.2%) from group c, 31 (68.9%) from group d, 28 (62.2%) from group e and 54 (67.5%) from group f had meniscal tear requiring treatment. The statistical analysis demonstrated that the earliest point of significantly higher incidence of meniscal tears was in patients undergoing ACLR more than 3 months post injury. Therefore, ACLR should be carried out within the first 3 months post injury in order to minimise the risk of secondary meniscal tears. PMID:17899001

  5. Principal component modeling of isokinetic moment curves for discriminating between the injured and healthy knees of unilateral ACL deficient patients.

    PubMed

    Almosnino, Sivan; Brandon, Scott C E; Day, Andrew G; Stevenson, Joan M; Dvir, Zeevi; Bardana, Davide D

    2014-02-01

    Bilateral knee strength evaluations of unilateral anterior cruciate ligament (ACL) deficient patients using isokinetic dynamometry are commonly performed in rehabilitation settings. The most frequently-used outcome measure is the peak moment value attained by the knee extensor and flexor muscle groups. However, other strength curve features may also be of clinical interest and utility. The purpose of this investigation was to identify, using Principal Component Analysis (PCA), strength curve features that explain the majority of variation between the injured and uninjured knee, and to assess the capabilities of these features to detect the presence of injury. A mixed gender cohort of 43 unilateral ACL deficient patients performed 6 continuous concentric knee extension and flexion repetitions bilaterally at 60°s(-1) and 180°s(-1) within a 90° range of motion. Moment waveforms were analyzed using PCA, and binary logistic regression was used to develop a discriminatory decision rule. For all directions and speeds, a statistically significant overall reduction in strength was noted for the involved knee in comparison to the uninvolved knee. The discriminatory decision rule yielded a specificity and sensitivity of 60.5% and 60.5%, respectively, corresponding to an accuracy of ∼62%. As such, the curve features extracted using PCA enabled only limited clinical usefulness in discerning between the ACL deficient and contra lateral, healthy knee. Improvement in discrimination capabilities may perhaps be achieved by consideration of different testing speeds and contraction modes, as well as utilization of other data analysis techniques. PMID:24280243

  6. Reduced knee joint moment in ACL deficient patients at a cost of dynamic stability during landing.

    PubMed

    Oberländer, Kai Daniel; Brüggemann, Gert-Peter; Höher, Jürgen; Karamanidis, Kiros

    2012-05-11

    The current study aimed to examine the effect of anterior cruciate ligament deficiency (ACLd) on joint kinetics and dynamic stability control after a single leg hop test (SLHT). Twelve unilateral ACLd patients and a control subject group (n=13) performed a SLHT over a given distance with both legs. The calculation of joint kinetics was done by means of a soft-tissue artifact optimized rigid full-body model. Margin of stability (MoS) was quantified by the difference between the base of support and the extrapolated center of mass. During landing, the ACLd leg showed lower external knee flexion moments but demonstrated higher moments at the ankle and hip compared to controls (p<0.05). The main reason for the joint moment redistribution in the ACLd leg was a more anterior position of the ground reaction force (GRF) vector, which affected the moment arms of the GRF acting about the joints (p<0.05). For the ACLd leg, trunk angle was more flexed over the entire landing phase compared to controls (p<0.05) and we found a significant correlation between moment arms at the knee joint and trunk angle (r² = 0.48;p<0.01). The consequence of this altered landing strategy in ACLd legs was a more anterior position of the center of mass reducing the MoS (p<0.05). The results illustrate the interaction between trunk angle, joint kinetics and dynamic stability during landing maneuvers and provide evidence of a feedforward adaptive adjustment in ACLd patients (i.e. more flexed trunk angle) aimed at reducing knee joint moments at the cost of dynamic stability control. PMID:22440611

  7. The Effect of ACL Reconstruction on Kinematics of the Knee with Combined ACL Injury and Subtotal Medial Meniscectomy - an in-vitro robotic investigation

    PubMed Central

    Seon, Jong Keun; Gadikota, Hemanth R.; Kozanek, Michal; Oh, Luke S.; Gill, Thomas J.; Li, Guoan

    2009-01-01

    Purpose The aims of this study were to determine: 1) the kinematic effect of subtotal medial meniscectomy on ACL deficient knee and 2) the effect of ACL reconstruction on kinematics of the knee with combined ACL deficiency and subtotal medial meniscectomy under an anterior tibial and a simulated quadriceps loads. Methods Eight human cadaveric knees were sequentially tested using a robotic testing system under 4 conditions: intact, ACL deficiency, ACL deficiency with subtotal medial meniscectomy, and single bundle ACL reconstruction using a bone-patellar tendon-bone graft. Knee kinematics were measured at 0°, 15°, 30°, 60°, and 90° of flex ion under an anterior tibial load of 130 N and a quadriceps muscle load of 400 N. Results Subtotal medial meniscectomy in ACL deficient knee significantly increased anterior and lateral tibial translations under the anterior tibial and quadriceps loads (P < 0.05). These kinematic changes were larger at high flexion (≥ 60°) than at low flexion angles. ACL reconstructio n in knees with ACL deficiency and subtotal medial meniscectomy significantly reduced the increased anterior tibial translation, but could not restore anterior translation to the intact level with differences ranging from 2.6 mm at 0° to 5.5 mm at 30° of flexion. ACL reconstruction did not significantly affect the medial-lateral translation and internal-external tibial rotation in the presence of subtotal meniscectomy. Conclusions Subtotal medial meniscectomy in knees with ACL deficiency altered knee kinematics, especially at high flexion angles. ACL reconstruction significantly reduced the increased tibial translation in knees with combined ACL deficiency and subtotal medial meniscectomy, but could not restore the knee kinematics to the intact knee level. Clinical Relevance This study suggests that meniscus is an important secondary stabilizer against anterior and lateral tibial translations and should be preserved in the setting of ACL reconstruction for

  8. Biomechanical Evaluation of Knee Kinematics after ACL Reconstructions in Anatomic SB and DB - Technique with Additional Medial Meniscus Suture

    PubMed Central

    Lorbach, Olaf; Herbort, Mirco; Engelhardt, Martin; Kieb, Matthias

    2013-01-01

    Objectives: Biomechanical evaluation of knee laxity after single- and double-bundle ACL reconstruction with additional medial meniscus suture. Methods: Kinematics of the intact knee were determined in 12 human cadaver specimens in response to a 134-N anterior tibial load (aTT) and a combined rotatory load of 10 Nm valgus and 4 Nm internal tibial rotation using a robotic/universal force moment sensor testing system. Subsequently, the ACL was resected following the creation of a bucket-handle tear of the medial meniscus. A standard repair of the medial meniscus was performed using 3 inside-out horizontal sutures. Finally, The ACL was reconstructed using an anatomic single-bundle (6) or double-bundle technique (6). Knee kinematics were determined following every sub-step. Results: Significant increase of aTT in the ACL-deficient knee was found with significant increase in the ACL-deficient knee with additional medial meniscal injury (p=.003; p=.009). ACL reconstructions significantly decreased aTT compared to the ACL-deficient knee. No significant differences were found between the intact knee and the ACL reconstructed knee with additional meniscal repair. In response to a simulated pivot shift, aTT in the intact knee significantly increased in the ACL-deficient knee as well as in the meniscus injured/meniscus-sutured knee (p=.003;p=.007). No significant differences were found between the ACL-deficient and ACL reconstructed knee with additional meniscal repair. SB as well as DB ACL reconstruction with additional medial meniscal repair restored knee kinematics compared to the intact knee. Comparison of SB versus DB ACL reconstruction did not reveal any significant differences neither in a simulated Lachman test nor in response to a simulated pivot shift (p=.05). Conclusion: aTT as well as aTT in response to a combined rotatory load significantly increased with ACL deficiency compared to the intact knee, additional medial meniscal injury further increased aTT. Anatomic

  9. Rehabilitation after ACL Injury: A Fluoroscopic Study on the Effects of Type of Exercise on the Knee Sagittal Plane Arthrokinematics

    PubMed Central

    Norouzi, Sadegh; Esfandiarpour, Fateme; Shakourirad, Ali; Salehi, Reza; Akbar, Mohammad; Farahmand, Farzam

    2013-01-01

    A safe rehabilitation exercise for anterior cruciate ligament (ACL) injuries needs to be compatible with the normal knee arthrokinematics to avoid abnormal loading on the joint structures. The objective of this study was to measure the amount of the anterior tibial translation (ATT) of the ACL-deficient knees during selective open and closed kinetic chain exercises. The intact and injured knees of fourteen male subjects with unilateral ACL injury were imaged using uniplanar fluoroscopy, while the subjects performed forward lunge and unloaded/loaded open kinetic knee extension exercises. The ATTs were measured from fluoroscopic images, as the distance between the tibial and femoral reference points, at seven knee flexion angles, from 0° to 90°. No significant differences were found between the ATTs of the ACL-deficient and intact knees at all flexion angles during forward lunge and unloaded open kinetic knee extension (P < 0.05). During loaded open kinetic knee extension, however, the ATTs of the ACL deficient knees were significantly larger than those of the intact knees at 0° (P = 0.002) and 15° (P = 0.012). It was suggested that the forward lunge, as a weight-bearing closed kinetic chain exercise, provides a safer approach for developing muscle strength and functional stability in rehabilitation program of ACL-deficient knees, in comparison with open kinetic knee extension exercise. PMID:24066288

  10. Knee instability scores for ACL reconstruction.

    PubMed

    Rahnemai-Azar, Ata A; Naendrup, Jan-Hendrik; Soni, Ashish; Olsen, Adam; Zlotnicki, Jason; Musahl, Volker

    2016-06-01

    Despite abundant biological, biomechanical, and clinical research, return to sport after anterior cruciate ligament (ACL) injury remains a significant challenge. Residual rotatory knee laxity has been identified as one of the factors responsible for poor functional outcome. To improve and standardize the assessment of knee instability, a variety of instability scoring systems is available. Recently, devices to objectively quantify static and dynamic clinical exams have been developed to complement traditional subjective grading systems. These devices enable an improved evaluation of knee instability and possible associated injuries. This additional information may promote the development of new treatment algorithms and allow for individualized treatment. In this review, the different subjective laxity scores as well as complementary objective measuring systems are discussed, along with an introduction of injury to an individualized treatment algorithm. PMID:26980119

  11. ACL mismatch reconstructions: influence of different tunnel placement strategies in single-bundle ACL reconstructions on the knee kinematics.

    PubMed

    Herbort, Mirco; Lenschow, Simon; Fu, Freddie H; Petersen, Wolf; Zantop, Thore

    2010-11-01

    To evaluate the influence of tibial and femoral tunnel position in ACL reconstruction on knee kinematics, we compared ACL reconstruction with a tibial and femoral tunnel in anteromedial (AM-AM reconstruction) and in posterolateral footprint (PL-PL reconstruction) with a reconstruction technique with tibial posterolateral and femoral anteromedial tunnel placement (PL-AM reconstruction). In 9 fresh-frozen human cadaveric knees, the knee kinematics under simulated Lachman (134 N anterior tibial load) and a simulated pivot shift test (10 N/m valgus and 4 N/m internal tibial torque) were determined at 0°, 30°, 60°, and 90° of flexion. Kinematics were recorded for intact, ACL-deficient, and single-bundle ACL reconstructed knees using three different reconstruction strategies in randomized order: (1) PL-AM, (2) AM-AM and (3) PL-PL reconstructions. Under simulated Lachman test, single-bundle PL-AM reconstruction and PL-PL reconstructions both showed significantly increased anterior tibial translation (ATT) at 60° and 90° when compared to the intact knee. At all flexion angles, AM-AM reconstruction did not show any statistical significant differences in ATT compared to the intact knee. Under simulated pivot shift, PL-AM reconstruction resulted in significantly higher ATT at 0°, 30°, and 60° knee flexion and AM-AM reconstructions showed significantly higher ATT at 30° compared to the intact knee. PL-PL reconstructions did not show any significant differences to the intact knee. AM-AM reconstructions restore the intact knee kinematics more closely when compared to a PL-AM technique resembling a transtibial approach. PL-PL reconstructions showed increased ATT at higher flexion angles, however, secured the rotational stability at all flexion angles. Due to the independent tibial and femoral tunnel location, a medial portal technique may be superior to a transtibial approach. PMID:20461359

  12. Articular cartilage of the knee 3 years after ACL reconstruction

    PubMed Central

    Bae, Ji-Hoon; Hosseini, Ali; Wang, Yang; Torriani, Martin; Gill, Thomas J; Grodzinsky, Alan J

    2015-01-01

    Background and purpose T1ρ or T2 relaxation imaging has been increasingly used to evaluate the cartilage of the knee. We investigated the cartilage of ACL-reconstructed knees 3 years after surgery using T2 relaxation times. Patients and methods 10 patients with a clinically successful unilateral ACL reconstruction were examined 3 years after surgery. Multiple-TE fast-spin echo sagittal images of both knees were acquired using a 3T MRI scanner for T2 mapping of the tibiofemoral cartilage. T2 values of the superficial and deep zones of the tibiofemoral cartilage were analyzed in sub-compartmental areas and compared between the ACL-reconstructed and uninjured contralateral knees. Results Higher T2 values were observed in 1 or more sub-compartmental areas of each ACL-reconstructed knee compared to the uninjured contralateral side. Most of the T2 increases were observed at the superficial zones of the cartilage, especially at the medial compartment. At the medial compartment of the ACL-reconstructed knee, the T2 values of the femoral and tibial cartilage were increased by 3–81% compared to the uninjured contralateral side, at the superficial zones of the weight-bearing areas. T2 values in the superficial zone of the central medial femoral condyle differed between the 2 groups (p = 0.002). Interpretation The articular cartilage of ACL-reconstructed knees, although clinically satisfactory, had higher T2 values in the superficial zone of the central medial femoral condyle than in the uninjured contralateral side 3 years after surgery. Further studies are warranted to determine whether these patients would undergo cartilage degeneration over time. PMID:25854533

  13. THE EFFECT OF CONSERVATIVELY TREATED ACL INJURY ON KNEE JOINT POSITION Sense

    PubMed Central

    Herrington, Lee

    2016-01-01

    ABSTRACT Background Proprioception is critical for effective movement patterns. However, methods of proprioceptive measurement in previous research have been inconsistent and lacking in reliability statistics making it applications to clinical practice difficult. Researchers have suggested that damage to the anterior cruciate ligament (ACL) can alter proprioceptive ability due to a loss of functioning mechanoreceptors. The majority of patients opt for reconstructive surgery following this injury. However, some patients chose conservative rehabilitation options rather than surgical intervention. Purpose The purpose of this study was to determine the effect of ACL deficiency on knee joint position sense following conservative, non-operative treatment and return to physical activity. A secondary purpose was to report the reliability and measurement error of the technique used to measure joint position sense, (JPS) and comment on the clinical utility of this measurement. Study Design Observational study design using a cross-section of ACL deficient patients and matched uninjured controls. Methods Twenty active conservatively treated ACL deficient patients who had returned to physical activity and twenty active matched controls were included in the study. Knee joint position sense was measured using a seated passive-active reproductive angle technique. The average absolute angle of error score, between 10 °-30 ° of knee flexion was determined. This error score was derived from the difference between the target and repositioning angle. Results The ACL deficient patients had a greater error score (7.9 °±3.6) and hence poorer static proprioception ability that both the contra-lateral leg (2.0 °±1.6; p = 0.0001) and the control group (2.6 °±0.9; p = 0.0001). The standard error of the mean (SEM) of this JPS technique was 0.5 ° and 0.2 ° and the minimum detectable change (MDC) was 1.3 ° and 0.4 ° on asymptomatic and symptomatic subjects

  14. A Preliminary In Vivo Assessment of Anterior Cruciate Ligament–Deficient Knee Kinematics With the KneeM Device

    PubMed Central

    Tardy, Nicolas; Marchand, Philippe; Kouyoumdjian, Pascal; Blin, Dominique; Demattei, Christophe; Asencio, Gérard

    2014-01-01

    Background: Methods of objectively measuring rotational knee laxity are either experimental or difficult to use in daily practice. A new method has been developed to quantitatively assess rotatory laxity using an open MRI system and new tool, the KneeM device. Purpose/Hypothesis: To perform a preliminary evaluation of a novel knee rotation measurement device to assess knee kinematics during flexion in an MRI field, in both anterior cruciate ligament (ACL)–deficient and healthy contralateral knees. The hypothesis was that the KneeM device would allow in vivo reproduction and analysis of knee kinematics during flexion in healthy and ACL-deficient knees. Study Design: Controlled laboratory study. Methods: Ten subjects (7 men and 3 women; mean age ± standard deviation, 32.3 ± 9.4 years) with ACL-deficient knees and contralateral uninjured knees participated in the study. An open MRI was performed with the KneeM device at a mean 4.9 months (range, 3.0-7 months) after ACL injury. The device exerted on the knee an anterior drawer force of 100 N, with an internal rotation of 20°, through the range of flexion (0°, 20°, 40°, and 60°). Both ACL-deficient and healthy contralateral knees were analyzed using the Iwaki method. Results: There was no statistical difference of anterior translation in the medial compartment between intact and ACL-deficient knees at all degrees of flexion. However, significant differences in the anterior translation of the lateral compartment were observed between ACL-deficient and intact contralateral knees at 0° and 20° of flexion (P = .005 and P = .002, respectively). Between 20° and 40°, the lateral plateau of ACL-deficient knees translated 7.7 mm posteriorly, whereas the medial compartment remained stable, reflecting a sudden external rotation of the lateral plateau under the femoral condyle. Conclusion: This preliminary study suggests that measurement of tibiofemoral movements in both compartments during flexion using the Knee

  15. Gender Dimorphic ACL Strain In Response to Combined Dynamic 3D Knee Joint Loading: Implications for ACL Injury Risk

    PubMed Central

    Mizuno, Kiyonori; Andrish, Jack T.; van den Bogert, Antonie J.; McLean, Scott G.

    2009-01-01

    While gender-based differences in knee joint anatomies/laxities are well documented, the potential for them to precipitate gender-dimorphic ACL loading and resultant injury risk has not been considered. To this end, we generated gender-specific models of ACL strain as a function of any six degrees of freedom (6DOF) knee joint load state via a combined cadaveric and analytical approach. Continuously varying joint forces and torques were applied to five male and five female cadaveric specimens and recorded along with synchronous knee flexion and ACL strain data. All data (~10,000 samples) were submitted to specimen-specific regression analyses, affording ACL strain predictions as a function of the combined 6 DOF knee loads. Following individual model verifications, generalized gender-specific models were generated and subjected to 6 DOF external load scenarios consistent with both a clinical examination and a dynamic sports maneuver. The ensuing model-based strain predictions were subsequently examined for gender-based discrepancies. Male and female specimen specific models predicted ACL strain within 0.51% ± 0.10% and 0.52% ± 0.07% of the measured data respectively, and explained more than 75% of the associated variance in each case. Predicted female ACL strains were also significantly larger than respective male values for both of simulated 6 DOF load scenarios. Outcomes suggest that the female ACL will rupture in response to comparatively smaller external load applications. Future work must address the underlying anatomical/laxity contributions to knee joint mechanical and resultant ACL loading, ultimately affording prevention strategies that may cater to individual joint vulnerabilities. PMID:19464897

  16. The effects of a valgus collapse knee position on in vivo ACL elongation.

    PubMed

    Utturkar, G M; Irribarra, L A; Taylor, K A; Spritzer, C E; Taylor, D C; Garrett, W E; Defrate, Louis E

    2013-01-01

    There are conflicting data regarding what motions increase ACL injury risk. More specifically, the mechanical role of valgus collapse positions during ACL injury remains controversial. Our objective was to evaluate ACL elongation in a model that mimics knee movements thought to occur during ACL injury. Eight healthy male subjects were imaged using MR and biplanar fluoroscopy to measure the in vivo elongation of the ACL and its functional bundles during three static knee positions: full extension, 30° of flexion, and a position intended to mimic a valgus collapse position described in the literature. For this study, the valgus collapse position consisted of 30° of knee flexion, internal rotation of the hip, and 10° of external tibial rotation. ACL length decreased significantly from full extension (30.2 ± 2.6 mm) to 30° of flexion (27.1 ± 2.2 mm). ACL length further decreased in the valgus collapse position (25.6 ± 2.4 mm). Both functional bundles of the ACL followed similar trends with regards to decreases in length in each of the three positions. Since strain would follow patterns of ACL length, landing on an extended knee may be a more relevant risk factor for ACL injuries than the valgus collapse position in males. Future studies should evaluate the effects of dynamic motion patterns on in vivo ACL strains. PMID:22855117

  17. Do ACL-injured copers exhibit differences in knee kinematics?: An MRI study.

    PubMed

    Barrance, Peter J; Williams, Glenn N; Snyder-Mackler, Lynn; Buchanan, Thomas S

    2007-01-01

    Kinematic changes after anterior cruciate ligament (ACL) injury may play a role in the long-term development of osteoarthritis (OA). Some ACL-injured patients (copers) successfully return to demanding activities without the reconstructive surgery usually recommended for functionally unstable patients (noncopers). We determined whether copers exhibit less disruption to kinematics than noncopers, perhaps because of lower impairment of muscular control as observed in earlier studies. We used dynamic magnetic resonance imaging and model-based tracking to investigate anteroposterior (AP) and internal-external tibial positioning in copers, presurgical noncopers, and uninjured control subjects during dynamic nonloaded knee extension. Copers and control subjects showed similar levels of side-to-side differences in AP tibial positioning (1.1 +/- 4.9 mm and 1.4 +/- 2.7 mm, respectively), whereas noncopers exhibited anterior tibial positioning in their injured knees (2.6 +/- 3 mm) that differed from control subjects. Copers were the most variable of the three groups, and contrary to our hypothesis, tibial positioning in copers was not different from that of noncopers. Differences in tibial positioning did not correlate with side-to-side differences in AP laxity in any of the groups, and we identified no changes to tibial axial rotation patterns associated with ACL deficiency. PMID:17091013

  18. Proprioception in the ACL-ruptured knee: the contribution of the medial collateral ligament and patellar ligament. An in vivo experimental study in the cat.

    PubMed

    Bonsfills, N; Raygoza, J J; Boemo, E; Garrido, J; Núñez, A; Gómez-Barrena, E

    2007-01-01

    In the absence of anterior cruciate ligament (ACL), secondary restraints such as menisci, ligaments, and tendons restrict anterior knee laxity. Strain detection at these sites could define the contribution of this alternative signalling system to knee proprioception after ACL injury. The hypothesis in this study questions if measurements of anterior tibial translation (ATT) from surface strain gauges on the insertions of the medial collateral ligament (MCL) and the patellar tendon (PT) are sufficiently sensitive and specific to differentiate normal, stable knees from acutely unstable knees due to ACL section. Twelve cats received miniaturized strain gauges on the surface of MCL and PT distal insertions. A purpose-made receiver transformed into measurements any voltage variation obtained during passive knee flexion-extension and anterior tibial translation manoeuvres. Variables under evaluation included first peak latency, normalized amplitude, and slope of voltage along time. Femorotibial displacements were video recorded, digitized, and used as the ATT reference. The proposed system detected significant changes in the slope of the voltage/time signal, with higher specificity and sensitivity during ATT after experimental ACL section. Changes were not significant during flexion or extension. It was found that a pattern of earlier and more intense strain in MCL and PT distal insertions was found during ATT in the ACL deficient knee. Enhanced pattern recognition learning from these structures could be a future target for proprioceptive training after ACL injury. PMID:17070686

  19. Management of Acute Combined ACL-Medial and Posteromedial Instability of the Knee.

    PubMed

    Medvecky, Michael J; Tomaszewski, Paul

    2015-06-01

    Medial collateral ligament (MCL) injuries are the most common ligamentous injury of the knee. The extent of injury can range from a minor first-degree (1-degree) sprain to an extensive third-degree (3-degree) sprain that can propagate across the knee, rupturing one or both cruciate ligaments, and result in a knee subluxation or dislocation. A common pattern involves the combined anterior cruciate ligament (ACL) and MCL injury that is the focus of this chapter. The vast majority of these combined medial-sided injuries are treated nonoperatively with delayed reconstruction of the ACL injury in athletically active individuals. The MCL and associated medial structures are carefully assessed on physical examination, and classification of injury is based upon abnormal limits of joint motion. In vitro cadaveric biomechanical testing has given us a better understanding of ligament deficiency and altered joint motion. Consistency in terminology is necessary for proper classification of injury and reproducible categorization of injury patterns to be able to compare both nonoperative and operative treatment of various injury patterns. PMID:25932883

  20. Nonsurgical or Surgical Treatment of ACL Injuries: Knee Function, Sports Participation, and Knee Reinjury

    PubMed Central

    Grindem, Hege; Eitzen, Ingrid; Engebretsen, Lars; Snyder-Mackler, Lynn; Risberg, May Arna

    2014-01-01

    Background: While there are many opinions about the expected knee function, sports participation, and risk of knee reinjury following nonsurgical treatment of injuries of the anterior cruciate ligament (ACL), there is a lack of knowledge about the clinical course following nonsurgical treatment compared with that after surgical treatment. Methods: This prospective cohort study included 143 patients with an ACL injury. Isokinetic knee extension and flexion strength and patient-reported knee function as recorded on the International Knee Documentation Committee (IKDC) 2000 form were collected at baseline, six weeks, and two years. Sports participation was reported monthly for two years with use of an online activity survey. Knee reinjuries were reported at the follow-up evaluations and in a monthly online survey. Repeated analysis of variance (ANOVA), generalized estimating equation (GEE) models, and Cox regression analysis were used to analyze group differences in functional outcomes, sports participation, and knee reinjuries, respectively. Results: The surgically treated patients (n = 100) were significantly younger, more likely to participate in level-I sports, and less likely to participate in level-II sports prior to injury than the nonsurgically treated patients (n = 43). There were no significant group-by-time effects on functional outcome. The crude analysis showed that surgically treated patients were more likely to sustain a knee reinjury and to participate in level-I sports in the second year of the follow-up period. After propensity score adjustment, these differences were nonsignificant; however, the nonsurgically treated patients were significantly more likely to participate in level-II sports during the first year of the follow-up period and in level-III sports over the two years. After two years, 30% of all patients had an extensor strength deficit, 31% had a flexor strength deficit, 20% had patient-reported knee function below the normal range, and

  1. The Meniscus-Deficient Knee

    PubMed Central

    Rao, Allison J.; Erickson, Brandon J.; Cvetanovich, Gregory L.; Yanke, Adam B.; Bach, Bernard R.; Cole, Brian J.

    2015-01-01

    Meniscal tears are the most common knee injury, and partial meniscectomies are the most common orthopaedic surgical procedure. The injured meniscus has an impaired ability to distribute load and resist tibial translation. Partial or complete loss of the meniscus promotes early development of chondromalacia and osteoarthritis. The primary goal of treatment for meniscus-deficient knees is to provide symptomatic relief, ideally to delay advanced joint space narrowing, and ultimately, joint replacement. Surgical treatments, including meniscal allograft transplantation (MAT), high tibial osteotomy (HTO), and distal femoral osteotomy (DFO), are options that attempt to decrease the loads on the articular cartilage of the meniscus-deficient compartment by replacing meniscal tissue or altering joint alignment. Clinical and biomechanical studies have reported promising outcomes for MAT, HTO, and DFO in the postmeniscectomized knee. These procedures can be performed alone or in conjunction with ligament reconstruction or chondral procedures (reparative, restorative, or reconstructive) to optimize stability and longevity of the knee. Complications can include fracture, nonunion, patella baja, compartment syndrome, infection, and deep venous thrombosis. MAT, HTO, and DFO are effective options for young patients suffering from pain and functional limitations secondary to meniscal deficiency. PMID:26779547

  2. Knee functional recovery and limb-to-limb symmetry restoration after anterior cruciate ligament (ACL) rupture and ACL reconstruction

    NASA Astrophysics Data System (ADS)

    Nawasreh, Zakariya Hussein

    Anterior cruciate ligament (ACL) rupture is a common sport injury of young athletes who participate in jumping, cutting, and pivoting activities. Although ACL reconstruction (ACLR) surgery has the goal of enabling athletes to return to preinjury activity levels, treatment results often fall short of this goal. The outcomes after ACLR are variable and less than optimal with low rate of return to preinjury activity level and high risk for second ACL injury. Factors related to the knee functional limitations, strength deficits, and limb-to-limb movement asymmetry may be associated with poor outcomes after ACLR. Additionally, the criteria that are used to determine a patient's readiness to return to the preinjury activity level are undefined which may also be associated with poor outcomes after ACLR. The clinical decision-making to clear patients' for safe and successful return to high physical activities should be based on a universal comprehensive set of objective criteria that ensure normal knee function and limb-to-limb symmetry. A battery of return to activity criteria (RTAC) that emphases normal knee function and limb-to-limb movement symmetry has been constituted to better ensure safe and successful return to preinjury activity level. Yet, only variables related to patients' demographics, concomitant injuries, and treatment measures have been used to predict return to preinjury activity levels after ACLR. However, the ability of RTAC variables that ensure normal knee function and limb movement symmetry to predict the return to participate in the same preinjury activity level after ACLR has not been investigated. In light of this background, the first aim of the present study was to compare functional knee performance-based and patient-reported measures of those who PASS and who FAIL on RTAC at 6 months (6-M) following ACLR with those at 12 months (12-M) and 24 months (24-M) following ACLR and to determine how performance-based and patient-reported measures

  3. Knee functional recovery and limb-to-limb symmetry restoration after anterior cruciate ligament (ACL) rupture and ACL reconstruction

    NASA Astrophysics Data System (ADS)

    Nawasreh, Zakariya Hussein

    Anterior cruciate ligament (ACL) rupture is a common sport injury of young athletes who participate in jumping, cutting, and pivoting activities. Although ACL reconstruction (ACLR) surgery has the goal of enabling athletes to return to preinjury activity levels, treatment results often fall short of this goal. The outcomes after ACLR are variable and less than optimal with low rate of return to preinjury activity level and high risk for second ACL injury. Factors related to the knee functional limitations, strength deficits, and limb-to-limb movement asymmetry may be associated with poor outcomes after ACLR. Additionally, the criteria that are used to determine a patient's readiness to return to the preinjury activity level are undefined which may also be associated with poor outcomes after ACLR. The clinical decision-making to clear patients' for safe and successful return to high physical activities should be based on a universal comprehensive set of objective criteria that ensure normal knee function and limb-to-limb symmetry. A battery of return to activity criteria (RTAC) that emphases normal knee function and limb-to-limb movement symmetry has been constituted to better ensure safe and successful return to preinjury activity level. Yet, only variables related to patients' demographics, concomitant injuries, and treatment measures have been used to predict return to preinjury activity levels after ACLR. However, the ability of RTAC variables that ensure normal knee function and limb movement symmetry to predict the return to participate in the same preinjury activity level after ACLR has not been investigated. In light of this background, the first aim of the present study was to compare functional knee performance-based and patient-reported measures of those who PASS and who FAIL on RTAC at 6 months (6-M) following ACLR with those at 12 months (12-M) and 24 months (24-M) following ACLR and to determine how performance-based and patient-reported measures

  4. Effects of ACL Reconstruction on In-Vivo, Dynamic Knee Function

    PubMed Central

    Tashman, Scott; Araki, Daisuke

    2012-01-01

    Synopsis The purposes of this article are to discuss key factors for assessing joint function, to present some recent findings and to address the future directions for evaluating the function of the ACL-injured/reconstructed knees. Well-designed studies, using state-of-the art tools to assess knee kinematics under in vivo, dynamic, high-loading conditions, are necessary to evaluate the relative performance of different procedures for restoring normal joint motion. PMID:23177461

  5. Persons with reconstructed ACL exhibit altered knee mechanics during high-speed maneuvers.

    PubMed

    Lee, S-P; Chow, J W; Tillman, M D

    2014-06-01

    Anterior cruciate ligament (ACL) injury is a sports trauma that causes long-term disability. The function of the knee during dynamic activities can be severely limited even after successful surgical reconstruction. This study examined the effects of approach velocity during side-step cutting on knee joint mechanics in persons with reconstructed ACL (ACLR). 22 participants (11 with unilateral ACLR, 11 matched-controls) participated. Knee joint mechanics were tested in 3 approach conditions: counter-movement, one-step, and running. Dependent variables, including peak knee flexion, extension, valgus, varus, internal rotation, external rotation angles and corresponding peak joint moments, were assessed during the stance phase of cutting. Two 2×3 ("group" by "approach condition") mixed MANOVA tests were used to examine the effects of ACLR and approach velocity on knee mechanics. ACLR participants exhibited higher knee internal rotator moment (0.22 vs. 0.13 Nm/kg, p=0.003). Inter-group comparisons revealed that the ACLR participants exhibited significantly higher abductor and internal rotator moments only in the running condition (1.86 vs. 1.16 Nm/kg, p=0.018; 0.28 vs. 0.17 Nm/kg, p=0.010, respectively). Our findings suggested that patients with ACLR may be at increased risk of re-injury when participating in high-demand physical activities. Task demand should be considered when prescribing progressive therapeutic interventions to ACLR patients. PMID:24408765

  6. An Unusual Case of Acl Cyst with Multiple Melon Seed Bodies of the Knee

    PubMed Central

    Vaish, Abhishek; Sancheti, Parag; Vaishya, Raju

    2016-01-01

    Introduction: The cyst of anterior cruciate ligament (ACL) is a known clinical entity, but its association with knee synovitis and melon or rice bodies is not documented. Case Report: We report a rare case of ganglionic cyst of of the knee in association with diffuse synovitis and multiple melon or rice bodies in a 36 year old male. The case was treated arthroscopically with removal ofthe cyst of ACL and multiple melon seed bodies. Conclusion: Information regarding incidence, treatment, and outcomes for patients with synovial cysts and melon seed bodies is lacking. Arthroscopic examination of joint gives the opportunity to diagnose such rare entity of the joint and also provide minimally invasive effective treatment of such pathology. PMID:27299116

  7. Knee Hyperextension as a Predictor of Failure in Revision ACL Reconstruction

    PubMed Central

    Cooper, Daniel E.; Dunn, Warren R.; Wright, Rick W.; Haas, Amanda; Huston, Laura J.

    2016-01-01

    Objectives: We studied the minimum 2 year follow-up outcomes in an ACL revision cohort. The hypothesis is that knees that hyperextend will have a worse outcome and greater odds of graft failure than knees that do not hyperextend. The null hypothesis is that there is no difference in outcomes or graft rupture between the two groups. Methods: Revision ACL reconstruction patients were identified and prospectively enrolled between 2006 and 2011. Data collected included baseline demographics, surgical technique and pathology, and a series of validated patient reported outcome instruments (IKDC, KOOS, WOMAC, and Marx activity rating score). Patients were followed up for 2 years, and asked to complete the identical set of outcome instruments. A regression model using graft failure as the dependent variable included graft type, age, and hyperextension greater than or equal to 5 degrees yes/no (HE) in order to assess these potential surgical risk factors for clinical outcomes 2 years after revision ACL reconstruction. Results: There were 1,145 subjects included in the analyses. The median age of the cohort was 26 (IQR= 20, 35), and 58% were male. The proportion that were enrolled for their first revision surgery was 88%, their second 10%, and third or greater 2%. The number of subjects categorized as HE was 375 (33%). The median age of subjects that failed was 18, compared to 26 for those with intact grafts. All three variables included in our regression model were significant predictors of graft failure: younger age, inter-quartile range odds ratio (IQROR) = 3.32 (95%CI 1.5, 7.2) p= 0.002; use of allograft OR = 3.1 (95%CI 1.4, 6.9) p= 0.01, and HE 2.1 (95%CI 1.02, 4.42) p= 0.04. Conclusion: The MARS Study Group has previously reported that young age and the use of allograft as a graft source are independent predictors (over 3X odds ratio) of graft rupture after revision ACLR. This study found that knee hyperextension greater than or equal to 5 degrees is present in 1/3 of

  8. Assessing the progress of rehabilitation in patients with ACL reconstruction using the International Knee Documentation Committee Subjective Knee Form

    NASA Astrophysics Data System (ADS)

    Leguizamon, J. H.; Braidot, A.; Catalfamo Formento, P.

    2011-12-01

    There are numerous assessment tools designed to provide information on the results of reconstructive surgery of anterior cruciate ligament (ACL). They are also used for monitoring progress and facilitating clinical decision-making during the rehabilitation process. A brief summary of some existing tools specifically designed to evaluate knee ligament injuries is presented in this article. Then, one of those outcome measures, the International Knee Documentation Committee Subjective Knee Form (IKDC) was applied to a group of patients (N = 10) who had undergone surgery for ACL reconstruction. The patients attended the same physiotherapy service and followed a unified rehabilitation protocol. The assessment was performed twice: four and six months after surgery. The results showed an improvement in the rehabilitation of most patients tested (verified by a difference equal to or greater than 9 points on the IKDC outcome between measurements 1 and 2). The IKDC probed to be an instrument of quick and easy application. It provided quantitative data about the progress of rehabilitation and could be applied in everyday clinical physiotherapy practice. However, the results suggested considering the IKDC as one component of an evaluation kit to make decisions regarding the progress of the rehabilitation treatment.

  9. In vivo determination of knee kinematics in patients with a hamstring or patellar tendon ACL graft.

    PubMed

    Mahfouz, Mohamed R; Traina, Steven M; Komistek, Richard D; Dennis, Douglas A

    2003-10-01

    Video fluoroscopy was used to assess the in vivo kinematics for patients with a patellar-tendon-bone or double-looped semitendinosus gracilis anterior cruciate ligament (ACL) graft. Patients with a double-looped semitendinosus gracilis ACL graft experienced kinematic patterns more similar to the normal knee than patients with a patellar-tendon-bone reconstruction. Patients with a double-looped semitendinosus gracilis reconstruction also experienced more anterior contact at full extension and throughout the flexion cycle than patients with a patellar-tendon-bone reconstruction, which resulted in patients with double-looped semitendinosus gracilis grafts experiencing more posterior femoral rollback. Therefore, removal of the central third of the patella ligament leads to a decrease in quadriceps mechanism efficiency, which resulted in the more posterior contact positions demonstrated by the patients with patellar-tendon-bone grafts in this study. PMID:14584831

  10. The role of the anterolateral ligament in ACL insufficient and reconstructed knees on rotatory stability: A biomechanical study on human cadavers.

    PubMed

    Tavlo, M; Eljaja, S; Jensen, J T; Siersma, V D; Krogsgaard, M R

    2016-08-01

    Studies suggest that the anterolateral ligament (ALL) is important for knee stability. The purpose was to clarify ALL's effect on rotatory and anterior-posterior stability in the anterior cruciate ligament (ACL)-insufficient and reconstructed knees and the effect of reconstruction of an insufficient ALL. Eighteen cadaveric knees were included. Stability was tested for intact (+ALL), detached (-ALL) and reconstructed (+ reALL) ALL, with ACL removed (-ACL) and reconstructed (+ACL) in six combinations. All were tested in 0, 30, 60, and 90 °C flexion. Anterior-posterior stability was measured with a rolimeter. Rotation with a torque of 8.85 Nm was measured photographically. The ALL was well defined in 78% of knees. ACL reconstruction had a significant effect on anterior-posterior stability. Detaching the ALL had a significant effect on internal rotatory stability and on anterior-posterior stability in ACL-insufficient knees. Reconstruction of ACL and ALL reestablished knee stability. The appearance of the ALL was not uniform. The ALL was an internal rotational stabilizer. Anatomical ALL reconstruction in combination with ACL reconstruction could reestablish stability. ALL reconstruction might be considered in patients with combined ACL and ALL tears, but the clinical effect should be established in a controlled clinical study. PMID:26247376

  11. Effect of whole body vibration frequency on neuromuscular activity in ACL-deficient and healthy males.

    PubMed

    Giombini, A; Menotti, F; Laudani, L; Piccinini, A; Fagnani, F; Di Cagno, A; Macaluso, A; Pigozzi, F

    2015-09-01

    Whole-body vibration (WBV) has been shown to enhance muscle activity via reflex pathways, thus having the potential to contrast muscle weakness in individuals with rupture of the anterior cruciate ligament (ACL). The present study aimed to compare the magnitude of neuromuscular activation during WBV over a frequency spectrum from 20 to 45 Hz between ACL-deficient and healthy individuals. Fifteen males aged 28±4 with ACL rupture and 15 age-matched healthy males were recruited. Root mean square (RMS) of the surface electromyogram from the vastus lateralis in both limbs was computed during WBV in a static half-squat position at 20, 25, 30, 35, 40 and 45 Hz, and normalized to the RMS while maintaining the half-squat position without vibration. The RMS of the vastus lateralis in the ACL-deficient limb was significantly greater than in the contralateral limb at 25, 30, 35 and 40 Hz (P<0.05) and in both limbs of the healthy participants (dominant limb at 25, 30, 35, 40 and 45 Hz, P<0.05; non dominant limb at 20, 25, 30, 35, 40 and 45 Hz, P<0.05). The greater neuromuscular activity in the injured limb compared to the uninjured limb of the ACL-deficient patients and to both limbs of the healthy participants during WBV might be due to either augmented excitatory or reduced inhibitory neural inflow to motoneurons of the vastus lateralis through the reflex pathways activated by vibratory stimuli. The study provides optimal WBV frequencies which might be used as reference values for ACL-deficient patients. PMID:26424928

  12. Effect of whole body vibration frequency on neuromuscular activity in ACL-deficient and healthy males

    PubMed Central

    Giombini, A; Menotti, F; Piccinini, A; Fagnani, F; Di Cagno, A; Macaluso, A; Pigozzi, F

    2015-01-01

    Whole-body vibration (WBV) has been shown to enhance muscle activity via reflex pathways, thus having the potential to contrast muscle weakness in individuals with rupture of the anterior cruciate ligament (ACL). The present study aimed to compare the magnitude of neuromuscular activation during WBV over a frequency spectrum from 20 to 45 Hz between ACL-deficient and healthy individuals. Fifteen males aged 28±4 with ACL rupture and 15 age-matched healthy males were recruited. Root mean square (RMS) of the surface electromyogram from the vastus lateralis in both limbs was computed during WBV in a static half-squat position at 20, 25, 30, 35, 40 and 45 Hz, and normalized to the RMS while maintaining the half-squat position without vibration. The RMS of the vastus lateralis in the ACL-deficient limb was significantly greater than in the contralateral limb at 25, 30, 35 and 40 Hz (P<0.05) and in both limbs of the healthy participants (dominant limb at 25, 30, 35, 40 and 45 Hz, P<0.05; non dominant limb at 20, 25, 30, 35, 40 and 45 Hz, P<0.05). The greater neuromuscular activity in the injured limb compared to the uninjured limb of the ACL-deficient patients and to both limbs of the healthy participants during WBV might be due to either augmented excitatory or reduced inhibitory neural inflow to motoneurons of the vastus lateralis through the reflex pathways activated by vibratory stimuli. The study provides optimal WBV frequencies which might be used as reference values for ACL-deficient patients. PMID:26424928

  13. Predictive mathematical modeling of knee static laxity after ACL reconstruction: in vivo analysis.

    PubMed

    Signorelli, C; Bonanzinga, T; Grassi, A; Lopomo, N; Zaffagnini, S; Marcacci, M

    2016-11-01

    Previous studies did not take into consideration such large variety of surgery variables which describe the performed anterior cruciate ligament (ACL) reconstruction and the interaction among them in the definition of postoperative outcome. Seventeen patients who underwent navigated Single Bundle plus Lateral Plasty ACL reconstruction were enrolled in the study. Static laxity was evaluated as the value of anterior/posterior displacement at 30° and at 90° of flexion, internal/external rotation at 30° and 90° of knee flexion, varus/valgus test at 0° and 30° of flexion. The evaluated surgical variables were analyzed through a multivariate analysis defining the following models: AP30estimate, AP90estimate, IE30estimate, IE90estimate, VV0estimate, VV30estimate. Surgical variables has been defined as the angles between the tibial tunnel and the three planes, the lengths of the tunnel and the relationship between native footprints and tunnels. An analogous characterization was performed for the femoral side. Performance and significance of the defined models have been quantified by the correlation ratio (η(2)) and the corresponding p-value (*p < 0.050). The analyzed models resulted to be statistically significant (p < 0.05) for prediction of postoperative static laxity values. The only exception was the AP90estimate model. The η(2) ranged from 0.568 (IE90estimate) to 0.995 (IE30estimate). The orientation of the tibial tunnel resulted to be the most important surgical variable for the performed laxity estimation. Mathematical models for postoperative knee laxity is a useful tool to evaluate the effects of different surgical variables on the postoperative outcome. PMID:27123692

  14. The effects of core muscle activation on dynamic trunk position and knee abduction moments: implications for ACL injury.

    PubMed

    Jamison, Steve T; McNally, Michael P; Schmitt, Laura C; Chaudhari, Ajit M W

    2013-09-01

    Anterior cruciate ligament (ACL) injury is one of the most common serious lower-extremity injuries experienced by athletes participating in field and court sports and often occurs during a sudden change in direction or pivot. Both lateral trunk positioning during cutting and peak external knee abduction moments have been associated with ACL injury risk, though it is not known how core muscle activation influences these variables. In this study, the association between core muscle pre-activation and trunk position as well as the association between core muscle pre-activation and peak knee abduction moment during an unanticipated run-to-cut maneuver were investigated in 46 uninjured individuals. Average co-contraction indices and percent differences between muscle pairs were calculated prior to initial contact for internal obliques, external obliques, and L5 extensors using surface electromyography. Outside tilt of the trunk was defined as positive when the trunk was angled away from the cutting direction. No significant associations were found between pre-activations of core muscles and outside tilt of the trunk. Greater average co-contraction index of the L5 extensors was associated with greater peak knee abduction moment (p=0.0107). Increased co-contraction of the L5 extensors before foot contact could influence peak knee abduction moment by stiffening the spine, limiting sagittal plane trunk flexion (a motion pattern previously linked to ACL injury risk) and upper body kinetic energy absorption by the core during weight acceptance. PMID:23891313

  15. Effect of ACL graft material on anterior knee force during simulated in vivo ovine motion applied to the porcine knee: An in vitro examination of force during 2000 cycles.

    PubMed

    Boguszewski, Daniel V; Wagner, Christopher T; Butler, David L; Shearn, Jason T

    2015-12-01

    This study determined how anterior cruciate ligament (ACL) reconstruction affected the magnitude and temporal patterns of anterior knee force and internal knee moment during 2000 cycles of simulated gait. Porcine knees were tested using a six degree-of-freedom robot, examining three porcine allograft materials compared with the native ACL. Reconstructions were performed using: (1) bone-patellar tendon-bone allograft (BPTB), (2) reconstructive porcine tissue matrix (RTM), or (3) an RTM-polymer hybrid construct (Hybrid). Forces and moments were measured over the entire gait cycle and contrasted at heel strike, mid stance, toe off, and peak flexion. The Hybrid construct performed the best, as magnitude and temporal changes in both anterior knee force and internal knee moment were not different from the native ACL knee. Conversely, the RTM knees showed greater loss in anterior knee force during 2000 cycles than the native ACL knee at heel strike and toe off, with an average force loss of 46%. BPTB knees performed the least favorably, with significant loss in anterior knee force at all key points and an average force loss of 61%. This is clinically relevant, as increases in post-operative knee laxity are believed to play a role in graft failure and early onset osteoarthritis. PMID:26134453

  16. Optimizing whole-body kinematics to minimize valgus knee loading during sidestepping: implications for ACL injury risk.

    PubMed

    Donnelly, C J; Lloyd, D G; Elliott, B C; Reinbolt, J A

    2012-05-11

    The kinematic mechanisms associated with elevated externally applied valgus knee moments during non-contact sidestepping and subsequent anterior cruciate ligament (ACL) injury risk are not well understood. To address this issue, the residual reduction algorithm (RRA) in OpenSim was used to create nine subject-specific, full-body (37 degrees of freedom) torque-driven simulations of athletic males performing unplanned sidestep (UnSS) sport tasks. The RRA was used again to produce an optimized kinematic solution with reduced peak valgus knee torques during the weight acceptance phase of stance. Pre-to-post kinematic optimization, mean peak valgus knee moments were significantly reduced by 44.2 Nm (p=0.045). Nine of a possible 37 upper and lower body kinematic changes in all three planes of motion were consistently used during the RRA to decrease peak valgus knee moments. The generalized kinematic strategy used by all nine simulations to reduce peak valgus knee moments and subsequent ACL injury risk during UnSS was to redirect the whole-body center of mass medially, towards the desired direction of travel. PMID:22387123

  17. Association between abnormal kinematics and degenerative change in knees of people with chronic anterior cruciate ligament deficiency: a magnetic resonance imaging study.

    PubMed

    Scarvell, Jennifer M; Smith, Paul N; Refshauge, Kathryn M; Galloway, Howard R; Woods, Kevin R

    2005-01-01

    Progressive degeneration of the anterior cruciate ligament (ACL) deficient knee may be partly due to chondral trauma at the time of ACL rupture and repeat episodes of subluxation, but also due to aberrant kinematics altering the wear pattern at the tibiofemoral interface. The hypothesis that altered kinematics, represented by the tibiofemoral contact pattern, would be associated with articular cartilage degeneration in ACL-deficient knees was tested in a cross-sectional study of 23 subjects with a history of > 10 years ACL deficiency without knee reconstruction. Subjects were aged 31 to 67 years. Eleven were male, 12 were female. Sagittal magnetic resonance imaging (MRI) scans enabled tibiofemoral contact mapping as subjects performed a closed-chain leg-press. Images were acquired at 15 degree intervals from 0 degrees to 90 degrees knee flexion. Articular cartilage degeneration was assessed by diagnostic MRI and where possible, arthroscopy. The ACL-deficient knees had a posterior tibiofemoral contact pattern on the tibial plateau compared to the healthy knees (F((1,171)) = 9.2, p = 0.003). The difference appeared to be seen in the medial compartment (F((1,171)) = 3.2, p = 0.07), though this failed to reach significance. Articular cartilage degeneration in the medial compartment was related to the variation of the tibiofemoral contact pattern (r = -0.53, p = 0.01). Articular cartilage degeneration was not related to time since injury (r = -0.16, p = 0.65). The association between aberrant kinematics and degenerative change may stimulate thinking on the role of dynamic stability and neuromuscular co-ordination in joint protection. PMID:16321130

  18. High knee abduction moments are common risk factors for patellofemoral pain (PFP) and anterior cruciate ligament (ACL) injury in girls: Is PFP itself a predictor for subsequent ACL injury?

    PubMed Central

    Myer, Gregory D; Ford, Kevin R; Di Stasi, Stephanie L; Foss, Kim D Barber; Micheli, Lyle J; Hewett, Timothy E

    2014-01-01

    Background Identifying risk factors for knee pain and anterior cruciate ligament (ACL) injury can be an important step in the injury prevention cycle. Objective We evaluated two unique prospective cohorts with similar populations and methodologies to compare the incidence rates and risk factors associated with patellofemoral pain (PFP) and ACL injury. Methods The ‘PFP cohort’ consisted of 240 middle and high school female athletes. They were evaluated by a physician and underwent anthropometric assessment, strength testing and three-dimensional landing biomechanical analyses prior to their basketball season. 145 of these athletes met inclusion for surveillance of incident (new) PFP by certified athletic trainers during their competitive season. The ‘ACL cohort’ included 205 high school female volleyball, soccer and basketball athletes who underwent the same anthropometric, strength and biomechanical assessment prior to their competitive season and were subsequently followed up for incidence of ACL injury. A one-way analysis of variance was used to evaluate potential group (incident PFP vs ACL injured) differences in anthropometrics, strength and landing biomechanics. Knee abduction moment (KAM) cut-scores that provided the maximal sensitivity and specificity for prediction of PFP or ACL injury risk were also compared between the cohorts. Results KAM during landing above 15.4 Nm was associated with a 6.8% risk to develop PFP compared to a 2.9% risk if below the PFP risk threshold in our sample. Likewise, a KAM above 25.3 Nm was associated with a 6.8% risk for subsequent ACL injury compared to a 0.4% risk if below the established ACL risk threshold. The ACL-injured athletes initiated landing with a greater knee abduction angle and a reduced hamstrings-to-quadriceps strength ratio relative to the incident PFP group. Also, when comparing across cohorts, the athletes who suffered ACL injury also had lower hamstring/quadriceps ratio than the players in the PFP

  19. Influence of Functional Knee Bracing on the Isokinetic and Functional Tests of Anterior Cruciate Ligament Deficient Patients

    PubMed Central

    Mortaza, Niyousha; Abu Osman, Noor Azuan; Jamshidi, Ali Ashraf; Razjouyan, Javad

    2013-01-01

    Use of functional knee braces has been suggested to provide protection and to improve kinetic performance of the knee in Anterior cruciate ligament(ACL)-injured patients. However, many athletes might refrain from wearing the braces because of the fear of performance hindrance in the playing field. The aim of this study was to examine the effect of three functional knee brace/sleeves upon the isokinetic and functional performance of ACL-deficient and healthy subjects. Six anterior cruciate ligament deficient (29.0±5.3 yrs., 175.2±5.4 cm, and 73.0±10.0 kg) and six healthy male subjects (27.2±3.7 yrs., 176.4±6.4 cm, and 70.3±6.9 kg) were selected. The effect of a custom-made functional knee brace, and two neoprene knee sleeves, one with four metal supports and one without support were examined via the use of isokinetic and functional tests in four sets (non-braced,wearing functional knee brace,and wearing the sleeves). Cross-over hop and single leg vertical jump test were performed and jump height, and hop distance were recorded. Peak torque to body weight ratio and average power in two isokinetic velocities(60°.s−1,180°.s−1) were recorded and the brace/sleeves effect was calculated as the changes in peak torque measured in the brace/sleeves conditions, expressed as a percentage of peak torque measured in non-braced condition. Frequency content of the isokinetic torque-time curves was also analyzed. Wilcoxon signed rank test was used to compare the measured values in four test conditions within each control and ACL-deficient group,and Mann-Whitney U test was used for the comparison between the two groups. No significant differences in peak torque, average power, torque-time curve frequency content, vertical-jump and hop measurements were found within the experimental and the non-braced conditions (p>0.05). Although the examined functional knee brace/sleeves had no significant effect on the knee muscle performance, there have been some enhancement regarding

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

    PubMed

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

    2015-01-01

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

  1. Extra-articular reconstruction in the anterior cruciate ligament deficient knee: a commentary

    PubMed Central

    FERRETTI, ANDREA

    2014-01-01

    The conclusions of the consensus conference organized in 1989 by the AOSSM in Snow mass on the Extra-articular reconstrucions in ACL deficient knee were reviewed in the light of the more recent advances in surgical techniques and rehabilitation. While most of the statements validated by the experts related to the use of ERs used in isolation and in adolescente patients have been confirmed by following studies, this paper pointed out that, on the contrary, the use of ERs in association with intra-articular reconstruction should be reconsidered and should be of great value in selected cases in order to improve knee stability, reduce rate of failure with no increased risk of complications and late degenerative osteoarthritis. PMID:25606541

  2. Comparison Between Strength of Muscles Rotating the Knee in Healthy Individuals and Patients one Year after an ACL Reconstruction

    PubMed Central

    Popieluch, Marcın; Śmigıelski, Robert; Straszewski, Darıusz; Plenzler, Marcın; Stanıszewski, Mıchał

    2014-01-01

    Objectives: In this study we have made an attempt to establish torque value of the muscles rotating the knee of patients who had ruptured their ACLs during an amateur football practise on an artificial turf. In this study we presented biomechanical research on torques of muscles responsible for internal and external rotation of the lower leg. We presented a method whereby it is possible to measure the muscle strength before and after the ACL rupture but also during the process of rehabilitation and after its finish. The available literature on measurements of torque of the knee is quite extensive though it mainly describes torques of muscles flexing and extending the joint. In Polish literature there is scarcity of studies focused on torques of muscles rotating the knee. In foreign literature there is an increasing emphasis on the role of lower leg rotation, as the element greatly impacting, for instance, the position of the foot. Methods: The study presents results of 22 patients and 50 healthy individuals (not practising any particular sport regularly) being the control group. All patients had their ACLs reconstructed using the double-bundle technique. The material for the graft was obtained from the hamstrings. The aim was to measure the maximal torque of the muscles responsible for external and internal rotation of the knee (lower leg in a static state using a special device). The device allowed measurement of the torque of muscles rotating the lower leg in its axis by stabilizing the ankle with special emphasis on foot mounting (stabilization of footwear). The special device was connected to a PC with CPS/HMF software. The software enabled observation and recording of increase in the value of the torque until it reached its maximum. The measurements were taken in two knee positions: 30 degrees and 90 degrees flexion. Results: The result were analyzed statistically, means and SDs were calculated. Only right-legged subjects were included in the analysis. The

  3. Multiple injections of leukoreduced platelet rich plasma reduce pain and functional impairment in a canine model of ACL and meniscal deficiency.

    PubMed

    Cook, James L; Smith, Patrick A; Bozynski, Chantelle C; Kuroki, Keiichi; Cook, Cristi R; Stoker, Aaron M; Pfeiffer, Ferris M

    2016-04-01

    Platelet rich plasma (PRP) is used to treat many musculoskeletal disorders. We used a canine model to determine the effects of multiple intra-articular injections of leukoreduced PRP (ACP) on anterior cruciate ligament healing, meniscal healing, and progression of osteoarthritis (OA). With Animal Care and Use Committee (ACUC) approval, 12 dogs underwent partial ACL transection and meniscal release in one knee. At weeks 1, 2, 3, 6, and 8 after insult, dogs were treated with intra-articular injections (2 ml) of either ACP (n = 6) or saline (n = 6). Dogs were assessed over 6 months to determine comfortable range of motion (CROM), lameness, pain, effusion, kinetics, and radiographic and arthroscopic assessments. At 6-month endpoint, dogs were assessed for ACL material properties and histopathology. Saline-treated dogs had significantly (p < 0.04) more CROM loss, significantly (p < 0.01) more pain, significantly (p < 0.05) more severe lameness, significantly (p < 0.05) lower function, and significantly (p < 0.05) lower %Total Pressure Index in affected hindlimbs compared to ACP-treated dogs. Radiographic OA increased significantly (p < 0.01) over time within each group. Arthroscopically, saline-treated knees showed moderate to severe synovitis, further ACL disruption, and medial compartment cartilage loss, and ACP-treated knees showed evidence of ACL repair and less severe synovitis. ACL material properties in ACP-treated knees were closer to normal than in saline-treated knees, however, the differences were not statistically significant. ACL histopathology was significantly (p< 0.05) less severe in ACP-treated knees compared to saline-treated knees. Five intra-articular injections of leukoreduced PRP had beneficial effects for ACL healing, improved range of motion, decreased pain, and improved limb function for up to 6 months in this model. PMID:26403590

  4. Biomechanical Deficiencies in Women with Semitendinosus-Gracilis ACL Reconstruction During Drop Jumps

    PubMed Central

    Ortiz, Alexis; Capo-Lugo, Carmen E.; Venegas-Rios, Heidi L.

    2014-01-01

    Objective To compare landing mechanics and neuromuscular recruitment strategies between women with semitendinosus-gracilis anterior cruciate ligament reconstruction (SG-ACLr) and non-injured women during double and single-legged drop jumps. Design Cross-sectional biomechanical study Setting Single university-based biomechanics laboratory Participants Fourteen women 1–5 years post SG-ACLr and 16 non-injured women participated in this study. Methods After anthropometric measurements, warm-up, and familiarization procedures, participants performed five trials of a double and single-legged drop jumps. Main Outcome Measurements Dynamic knee valgus was measured as the distance between knee joints during the landing phase of the double-leg drop jumps. Medial knee displacement was the outcome considered during the landing phase of the single-leg drop jumps. For both drop jumps tasks neuromuscular recruitment was evaluated through rectified normalized electromyography (EMG) activity of the quadriceps and hamstrings (amplitude and latency), and quadriceps/hamstrings EMG co-contraction ratio. Results Although the SG- ACLr group demonstrated a tendency towards a greater dynamic knee valgus during both drop jumps, these differences did not reach statistical significance. EMG data revealed different neuromuscular strategies for each group depending on the specific jump. Conclusions These findings suggest that women with SG-ACLr have a tendency towards greater dynamic knee valgus which could predispose to additional knee injuries. Rehabilitation specialists need to be aware of existing kinematic and neuromuscular deficiencies years after SG-ACLr. Taking this into consideration will aid in prescribing appropriate interventions designed to prevent re-injury. PMID:25043260

  5. KNEE SYNERGISM DURING GAIT REMAIN ALTERED ONE YEAR AFTER ACL RECONSTRUCTION

    PubMed Central

    LEPORACE, GUSTAVO; METSAVAHT, LEONARDO; PEREIRA, GLAUBER RIBEIRO; OLIVEIRA, LISZT PALMEIRA DE; CRESPO, BERNARDO; BATISTA, LUIZ ALBERTO

    2016-01-01

    ABSTRACT Objective: To compare the activation of the vastus lateralis (VL) and biceps femoris (BF) muscles during gait, as well VL/BF muscular co-contraction (MCC) between healthy (CG) and anterior cruciate ligament reconstructed (ACL-R) subjects. Methods: Nineteen subjects, ten controls and nine ACL-R patients had a VL and BF electromyogram (EMG) captured to calculate the MCC ratio. A Principal Component (PC) Analysis was applied to reduce the dimensionality effect of each of the MCC, VL and BF curves for both healthy and ACL reconstructed groups. The PC scores were used to calculate the standard distance (SD). SD values were employed in order to compare each dependent variable (MCC, VL and BF) between the two groups using unpaired t-test. Results: ACL-R group presented a lower VL activation at the beginning and at the end of the gait cycle, as compared to the control group. However, no difference was found for BF or VL/BF MCC. Conclusion: The gait analysis of ACL reconstructed patients demonstrated a persistent deficit in VL activation when compared to the control group, even one year after surgery. Level of Evidence III. Case Control Study PMID:27217814

  6. Bilateral ACL Reconstructions with Hamstring Autografts.

    PubMed

    Panigrahi, Ranajit; Mahapatra, Amita Kumari; Priyadarshi, Ashok; Palo, Nishit; Biswal, Manas R

    2016-07-01

    Bilateral anterior cruciate ligament (ACL) injuries are rare with incidence between 2 and 4%, and presently no definitive guidelines for proper management exist. Ideal treatment protocol remains controversial between a single-stage and two-stage bilateral ACL reconstruction. The purpose of this study is to evaluate the outcome of single-stage bilateral ACL reconstruction with hamstring tendon autografts in bilateral ACL injuries. A prospective study was undertaken including a total of 14 consecutive patients with bilateral ACL deficient knee who underwent single-stage bilateral ACL reconstruction with hamstring tendon autograft with a mean follow-up duration of 28 months (24-38 months). Functional outcomes were evaluated by range of movements, International Knee Documentation Committee (IKDC), Lysholm and Tegner activity score, and stability tests. The mean age was 30 years (range 18-42 years). Average duration of rehabilitation was 8 weeks. Time to return to full-time work and full sports was 5.6 weeks and 6.2 months, respectively. Clinical examination demonstrated full range of motion; a total of 12 patients (86%) had a negative Lachman test and 13 patients (93%) had a negative pivot shift at the final follow-ups. The mean IKDC evaluation score was 89 points, the mean Tegner activity score was 7 points, and the mean Lysholm knee score was 91 points. A total of 12 patients (86%) returned to their preinjury level of activity and an overall greater than 90% satisfaction rate was achieved. Single-stage bilateral ACL reconstruction using hamstring autografts is clinically safe, effective, and cost-effective with better patient compliance and with comparable functional outcome as opposed to two-stage ACL reconstructions. PMID:26408992

  7. Electromechanical delay of the knee extensor muscles is not altered after harvesting the patellar tendon as a graft for ACL reconstruction: implications for sports performance.

    PubMed

    Georgoulis, A D; Ristanis, S; Papadonikolakis, A; Tsepis, E; Moebius, U; Moraiti, C; Stergiou, N

    2005-09-01

    Although the scar tissue, which heals the donor site defect, has different elasticity from the neighbouring patellar tissue, it remains unclear if this scar tissue can lead to the changes of the electromechanical delay (EMD) of the knee extensor muscles. If such changes do exist, they can possibly affect both the utilization of the stored energy in the series elastic component, as well as the optimal performance of the knee joint movement. The purpose of this study was to investigate the influence of harvesting the patellar tendon during anterior cruciate ligament (ACL) reconstruction and the associated patellar tendon scar tissue development on the EMD of the rectus femoris (RF) and vastus medialis (VM) muscles. Seventeen patients who underwent an ACL reconstruction using the medial third of the patellar tendon were divided in two groups based upon their post-operative time interval. Maximal voluntary contraction from the knee extensors, surface EMG activity, and ultrasonographic measurements of the patellar tendon cross-section area were obtained from both knees. Our results revealed that no significant changes for the maximal voluntary contraction of the knee extensors and for the EMD of the RF and the VM muscles due to patellar scar tissue development after harvesting the tendon for ACL reconstruction. The EMD, as a component of the stretch reflex, is important for the utilization of the stored energy in the series elastic component and thus, optimal sports performance. However, from our results, it can be implied that the ACL reconstruction using a patellar tendon graft would not impair sports performance as far as EMD is concerned. PMID:15968530

  8. Effect of brace design on patients with ACL-ruptures.

    PubMed

    Strutzenberger, G; Braig, M; Sell, S; Boes, K; Schwameder, H

    2012-11-01

    Different designs of functional knee braces for ACL-injury rehabilitation exist. In addition to the mechanical stabilization provided by rigid shell braces, sleeve braces also address proprioceptive mechanisms, but little is known if this leads to benefits for ACL-deficient subjects. Therefore the aim of this study was to investigate the effect of 2 different functional brace designs (shell and sleeve brace) on functional achievements in ACL-deficient patients. 28 subjects with ACL-ruptured knees performed tests for knee joint laxity, joint position sense, static and dynamic balance and isometric and dynamic lower limb extension strength in non-braced, sleeve braced and shell braced condition. The results showed a significant decrease in knee joint laxity for sleeve (33%; p<0.001) and rigid shell bracing (14%, p=0.039). The sleeve brace revealed a significant increase in dynamic balance after perturbation (20%; p=0.024) and a significant increase in dynamic lower limb peak rate of force development (17%; p=0.015) compared to the non-braced condition. The effects might be caused by the flexible area of support and the incorporated mechanisms to address proprioceptive aspects. Braces might not be needed in simple daily life tasks, but could provide beneficial support in more dynamic settings when patients return to sporting activities after an ACL-injury. PMID:22706937

  9. Anterolateral Extra-articular Soft Tissue Reconstruction in Anterolateral Rotatory Instability of the Knee.

    PubMed

    Kernkamp, Willem A; van de Velde, Samuel K; Bakker, Eric W P; van Arkel, Ewoud R A

    2015-12-01

    Anterolateral rotatory instability (ALRI) occurs after injury to the anterior cruciate ligament (ACL) and the anterolateral structures of the knee. We present a technique for anterolateral extra-articular soft-tissue (ALES) reconstruction of the knee that can be used in revision ACL reconstruction cases, cases of persistent ALRI after adequate ACL reconstruction, and cases with severe ALRI after primary ACL rupture. The surgeon performs ALES reconstruction with a strip of iliotibial tract autograft while respecting the anatomic origin and insertion of the anterolateral ligament. The purpose of this reconstruction is to restore the normal anterolateral rotatory stability of the knee in ALES-deficient patients. PMID:27284525

  10. Analysis of the Three Most Prevalent Injuries in Australian Football Demonstrates a Season to Season Association Between Groin/Hip/Osteitis Pubis Injuries With ACL Knee Injuries

    PubMed Central

    Verrall, Geoffrey M.; Esterman, Adrian; Hewett, Timothy E.

    2014-01-01

    Background: Injuries are common in contact sports like Australian football. The Australian Football League (AFL) has developed an extensive injury surveillance database that can be used for epidemiological studies. Objectives: The purpose of this study is to identify any association between the three most prevalent injuries in the AFL. Patients and Methods: From the AFL injury surveillance data 1997-2012 the injury incidence (new injuries per club per season) and the injury prevalence data (missed games per club per season) were analysed to detect the three most common injuries that would cause a player to miss a match in the AFL. The three most prevalent injuries in the AFL are hamstring strains, groin/hip/osteitis pubis injuries and Anterior Cruciate Ligament (ACL) knee injuries. Following this, further study was undertaken to detect the presence of any statistical relationship between injury incidences of the three most prevalent injuries over this sixteen year study period. Results: Statistical analysis demonstrates for any given year that there was an association between having a groin/hip/osteitis pubis injuriy and having a knee ACL injury (P < 0.05) over the entire sixteen years. In other words if the number of groin/hip/osteitis pubis injuries in any given season were higher than average (alternatively lower) then the number of knee ACL injuries were also higher than average (alternatively lower) for that same season. Hamstring injuries had the highest variance of incidence of the three most prevalent injuries. Conclusions: Analysis of the AFL injury data demonstrates an association between incidence of groin/hip/osteitis pubis injuries and incidence of knee ACL injuries for any given playing season. This finding is difficult to explain with further research being required. PMID:25520768

  11. Knee stability, athletic performance and sport-specific tasks in non-professional soccer players after ACL reconstruction: comparing trans-tibial and antero-medial portal techniques

    PubMed Central

    Tudisco, Cosimo; Bisicchia, Salvatore; Cosentino, Andrea; Chiozzi, Federica; Piva, Massimo

    2015-01-01

    Summary Background a wrong position of bone tunnels, in particular on the femur, is one of the most frequent causes of a failed anterior cruciate ligament (ACL) reconstruction. Several studies demonstrated that drilling the femoral tunnel through the antero-medial portal (AMP) allows a more anatomical placement on the lateral femoral condyle and higher knee stability, compared to trans-tibial (TT) technique. The aim of this study was to retrospectively evaluate two groups of soccer players operated on for ACL reconstruction according to either one of these two techniques. Methods two groups of non-professional soccer players operated on for a single bundle ACL reconstruction with hamstrings autograft using either a TT (20 patients) or an AMP (23 patients) technique were retrospectively evaluated with KT-1000 arthrometer, manual pivot shift test, isokinetic test, the incremental treadmill-running test, athletic and sport specific tasks, and knee scores (IKDC, Lysholm and KOOS). Results the AMP group showed better results at pivot shift test and KOOS, but lower flexion angles at single leg squat test. There were no differences in all the other considered outcomes. Conclusions the better rotational stability of the knee achieved in AMP group did not lead to significantly better clinical and functional results in our patients. Level of evidence III. Treatment study Case-control study. PMID:26605191

  12. Knee pain

    MedlinePlus

    ... the front of your knee around the kneecap Torn ligament. An anterior cruciate ligament (ACL) injury, or ... into your knee, swelling, or an unstable knee. Torn cartilage (a meniscus tear ). Pain felt on the ...

  13. The Meniscus-Deficient Knee: Biomechanics, Evaluation, and Treatment Options.

    PubMed

    Rao, Allison J; Erickson, Brandon J; Cvetanovich, Gregory L; Yanke, Adam B; Bach, Bernard R; Cole, Brian J

    2015-10-01

    Meniscal tears are the most common knee injury, and partial meniscectomies are the most common orthopaedic surgical procedure. The injured meniscus has an impaired ability to distribute load and resist tibial translation. Partial or complete loss of the meniscus promotes early development of chondromalacia and osteoarthritis. The primary goal of treatment for meniscus-deficient knees is to provide symptomatic relief, ideally to delay advanced joint space narrowing, and ultimately, joint replacement. Surgical treatments, including meniscal allograft transplantation (MAT), high tibial osteotomy (HTO), and distal femoral osteotomy (DFO), are options that attempt to decrease the loads on the articular cartilage of the meniscus-deficient compartment by replacing meniscal tissue or altering joint alignment. Clinical and biomechanical studies have reported promising outcomes for MAT, HTO, and DFO in the postmeniscectomized knee. These procedures can be performed alone or in conjunction with ligament reconstruction or chondral procedures (reparative, restorative, or reconstructive) to optimize stability and longevity of the knee. Complications can include fracture, nonunion, patella baja, compartment syndrome, infection, and deep venous thrombosis. MAT, HTO, and DFO are effective options for young patients suffering from pain and functional limitations secondary to meniscal deficiency. PMID:26779547

  14. The Anterolateral Ligament of the Knee: What the Radiologist Needs to Know.

    PubMed

    Van Dyck, Pieter; De Smet, Eline; Lambrecht, Valérie; Heusdens, Christiaan H W; Van Glabbeek, Francis; Vanhoenacker, Filip M; Gielen, Jan L; Parizel, Paul M

    2016-02-01

    The anterolateral ligament (ALL) was recently identified as a distinct component of the anterolateral capsule of the human knee joint with consistent origin and insertion sites. Biomechanical studies revealed that the current association between the pivot shift and an injured anterior cruciate ligament (ACL) should be loosened and that the rotational component of the pivot shift is significantly affected by the ALL. This may change the clinical approach toward ACL-injured patients presenting with anterolateral rotatory instability (ALRI), the most common instability pattern after ACL rupture. Radiologists should be aware of the importance of the ALL to ACL injuries. They should not overlook pathology of the anterolateral knee structures, including the ALL, when reviewing MR images of the ACL-deficient knee. In this article, the current knowledge regarding the anatomy, biomechanical function, and imaging appearance of the ALL of the knee is discussed with emphasis on the clinical implications of these findings. PMID:27077584

  15. Complete ACL/MCL deficiency induces variable degrees of instability in sheep with specific kinematic abnormalities correlating with degrees of early osteoarthritis.

    PubMed

    Frank, Cyril B; Beveridge, Jillian E; Huebner, Kyla D; Heard, Bryan J; Tapper, Janet E; O'Brien, Etienne J O; Shrive, Nigel G

    2012-03-01

    People are not equally disabled by combined anterior cruciate ligament (ACL)/medial collateral ligament (MCL) injuries, nor do they all develop osteoarthritis (OA). Although biological/biomechanical causes are not clear, some association presumably exists between joint instability and OA development. We hypothesized that degree of OA development following standardized complete ACL/MCL injuries will vary directly with the degree of biomechanical abnormality between individuals. Three groups of sheep were used to test the hypothesis: 17 normal, 9 ACL/MCL transected, and 7 sham animals. Normal joints were assessed morphologically while sham and experimental animals had gait assessment pre- and at 4 and 20 weeks post-surgery, with cartilage and bone changes being mapped and graded at sacrifice at 20 weeks. Sham joints were morphologically normal and had only one minor kinematic change at 20 weeks. Although variable, ACL/MCL deficient animals showed significant kinematic abnormalities in 4/6 degrees of freedom (DOFs), as well as cartilage/bone damage by 20 weeks (p < 0.05). Linear regression analysis revealed that changes in medial-lateral (ML) translation were related to the current level of joint degradation as represented by total gross OA score (p = 0.0044, R(2)  = 0.71) in the ACL/MCL transected group. Even identical ACL/MCL injuries result in inter-animal variations in instability and OA, however significant kinematic abnormalities in ML translation do relate to early OA in sheep. PMID:21919045

  16. Self-reported Knee Function Can Identify Athletes Who Fail Return to Activity Criteria up to 1 Year after Anterior Cruciate Ligament Reconstruction. A Delaware-Oslo ACL Cohort Study

    PubMed Central

    Logerstedt, David; Stasi, Stephanie Di; Grindem, Hege; Lynch, Andrew; Eitzen, Ingrid; Engebretsen, Lars; Risberg, May Arna; Axe, Michael J; Snyder-Mackler, Lynn

    2014-01-01

    STUDY DESIGN Cohort study, cross-sectional. OBJECTIVES To determine if self-reported knee function assessed with the International Knee Documentation Committee 2000 Subjective Knee Form (IKDC2000) could discriminate between successful and non-successful performance on return to activity criteria (RTAC) tests after anterior cruciate ligament (ACL) reconstruction. BACKGROUND Rehabilitation specialists are challenged in selecting appropriate performance-based and patient-reported tests that can detect side-to-side asymmetries, assess global knee function, and determine a participant's readiness to return to activity after ACL reconstruction. A simple tool or questionnaire that could identify athletes with neuromuscular impairments or activity limitations could provide rehabilitation specialists crucial data pertinent to their current knee function and their readiness to return to higher level activities. METHODS One hundred fifty-eight Level I/II athletes 6 months after ACL reconstruction and 141 athletes 12 months after ACL reconstruction completed a functional test battery to determine readiness to return to activity and the IKDC2000 to determine self-reported knee function. For each athlete, status on return to activity tests criteria was dichotomized as “Passed” or ”Failed” and status on the IKDC2000 scores was dichotomized as being “within” or “below age- and sex-matched normal ranges”. Comparisons were made between status on RTAC and IKDC2000 using Chi-square tests. Accuracy statistics were also calculated. RESULTS Six months after ACL reconstruction, 112 athletes (70.9%) failed RTAC and 76 (48.1%) were classified as having self-reported knee function below normal ranges. Among the 76 participants with IKDC2000 scores below normal ranges, 69 (90.8%) failed RTAC test battery (P<.001). However, among the 82 participants whose IKDC2000 scores were within normal limits at 6 months, only 39 (47.6%) passed RTAC test battery (P=.74). Twelve months after

  17. Elastic properties of an intact and ACL-ruptured knee joint: measurement, mathematical modelling, and haptic rendering.

    PubMed

    Frey, Martin; Riener, Robert; Michas, Christian; Regenfelder, Felix; Burgkart, Rainer

    2006-01-01

    An analytical, dynamic model of the human knee joint has been developed to simulate the unloaded knee joint behaviour in 6 degrees of freedom. It is based on extensive robot-based measurements of the elastic properties of a human cadaver knee joint. The measured data are compared with data from the literature to ensure that a proper database for modelling is used. The analytical modelling of the passive elastic joint properties is done with Local Linear Model Trees. The deduced knee joint model incorporates passive elastic properties of the internal knee joint structures, passive elastic muscle forces, damping forces, gravitational forces, and external forces. There are two sets of parameters, one simulating the movement of the intact knee joint, and a second simulating the knee joint with ruptured anterior cruciate ligament. The dynamic model can be easily processed in real-time. It is implemented in the haptic display of the Munich Knee Joint Simulator (MKS), which enables a person to move a plastic leg driven by a robot manipulator and feel the simulated knee joint force. Orthopaedic physicians judged the performance of the dynamic knee joint model by executing physical knee joint tests at the MKS. PMID:16039659

  18. The Relationship between Anterior Cruciate Ligament Injury and Osteoarthritis of the Knee

    PubMed Central

    Simon, David; Saltzman, Bryan M.; Rollins, Meaghan; Bach, Bernard R.; MacDonald, Peter

    2015-01-01

    Anterior cruciate ligament (ACL) tears are a common injury, particularly in the athletic and youth populations. The known association between ACL injury and subsequent osteoarthritis (OA) of the knee merits a more in-depth understanding of the relationship between the ACL-injured knee and osteoarthritis. ACL injury, especially with concomitant meniscal or other ligamentous pathology, predisposes the knee to an increased risk of osteoarthritis. ACL insufficiency results in deterioration of the normal physiologic knee bending culminating in increased anterior tibial translation and increased internal tibial rotation. This leads to increased mean contact stresses in the posterior medial and lateral compartments under anterior and rotational loading. However, surgical reconstruction of the ACL has not been shown to reduce the risk of future OA development back to baseline and has variability based on operative factors of graft choice, timing of surgery, presence of meniscal and chondral abnormalities, and surgical technique. Known strategies to prevent OA development are applicable to patients with ACL deficiency or after ACL reconstruction and include weight management, avoidance of excessive musculoskeletal loading, and strength training. Reconstruction of the ACL does not necessarily prevent osteoarthritis in many of these patients and may depend on several external variables. PMID:25954533

  19. ACL/MCL transection affects knee ligament insertion distance of healing and intact ligaments during gait in the Ovine model.

    PubMed

    Tapper, Janet E; Funakoshi, Yusei; Hariu, Mitsuhiro; Marchuk, Linda; Thornton, Gail M; Ronsky, Janet L; Zernicke, Ron; Shrive, Nigel G; Frank, Cyril B

    2009-08-25

    The objective of this study was to assess the impact of combined transection of the anterior cruciate and medial collateral ligaments on the intact and healing ligaments in the ovine stifle joint. In vivo 3D stifle joint kinematics were measured in eight sheep during treadmill walking (accuracy: 0.4+/-0.4mm, 0.4+/-0.4 degrees ). Kinematics were measured with the joint intact and at 2, 4, 8, 12, 16 and 20 weeks after either surgical ligament transection (n=5) or sham surgery without transection (n=3). After sacrifice at 20 weeks, the 3D subject-specific bone and ligament geometry were digitized, and the 3D distances between insertions (DBI) of ligaments during the dynamic in vivo motion were calculated. Anterior cruciate ligament/medial collateral ligament (ACL/MCL) transection resulted in changes in the DBI of not only the transected ACL, but also the intact lateral collateral ligament (LCL) and posterior cruciate ligament (PCL), while the DBI of the transected MCL was not significantly changed. Increases in the maximal ACL DBI (2 week: +4.2mm, 20 week: +5.7mm) caused increases in the range of ACL DBI (2 week: 3.6mm, 20 week: +3.8mm) and the ACL apparent strain (2 week: +18.9%, 20 week: +24.0%). Decreases in the minimal PCL DBI (2 week: -3.2mm, 20 week: -4.3mm) resulted in increases in the range of PCL DBI (2 week: +2.7mm, 20 week: +3.2mm). Decreases in the maximal LCL DBI (2 week: -1.0mm, 20 week: -2.0mm) caused decreased LCL apparent strain (2 week: -3.4%, 20 week: -6.9%). Changes in the mechanical environment of these ligaments may play a significant role in the biological changes observed in these ligaments. PMID:19643414

  20. Effect of Intraoperative Platelet-Rich-Plasma Treatment on Post Operative Donor Site Knee Pain in Patellar Tendon Autograft ACL Reconstruction

    PubMed Central

    Walters, Brian L.; Hobart, Sarah; Porter, David; Hogan, Daniel E.; McHugh, Malachy P.; Bedford, Benjamin B.; Nicholas, Stephen J.; Klein, Devon; Harousseau, Kendall

    2016-01-01

    Objectives: Donor site morbidity in the form of anterior knee pain is a frequent complication after bone-patellar tendon-bone (BPTB) autograft ACL reconstruction. The purpose of this Level I study was to examine the effect of the intraoperative administration of platelet-rich plasma on post operative knee pain and patellar defect healing. Methods: Fifty-nine patients (29±12 y/o) undergoing BPTB ACL reconstruction and eligible to enter the study, were randomized to the treatment (PRP; n=31) or non treatment (sham n=28) arms of the study just prior to surgery. In either case, 10 cc of venous blood was drawn prior to the induction of anesthesia and either discarded (sham) or processed (PRP) for preparation of a PRP gel to be later mixed with donor site bone chips and inserted into the patellar defect. At 12 weeks and 6 months after surgery, patients completed IKDC forms and VAS pain scores for ADLs and kneeling (0-10 scale). Healing indices at the donor site were assessed by MRI at 6 months and included the following measurements taken from axial sequences: AP tendon dimensions at the level of the superior tibial cortex, roof of the intercondylar notch and width at the largest patella graft deficit. Mixed model ANOVA was used to assess the effect of PRP on patient symptoms and MRI indices of donor site healing. The primary dependent variable was VAS kneeling pain. It was estimated that with 25 patients per group there would be 80% power to detect a 1.5-point difference in kneeling pain between treatments at P<0.05. A between group difference of 1.5-points in VAS for kneeling pain was deemed to represent a clinically relevant difference. Results: VAS Kneeling Pain at 12 weeks tended to be lower in the PRP versus placebo group (4.5±3.6 vs. 6.2±2.4, P=0.051) but no difference was apparent at 6 months (3.7±3.2 vs. 4.4±2.9, P=0.41). Kneeling pain decreased from 12 weeks to 6 months (P<0.001) with a trend for a greater decrease in the placebo group (Time by Treatment P

  1. The Effect of NeuroMuscular Electrical Stimulation on Quadriceps Strength and Knee Function in Professional Soccer Players: Return to Sport after ACL Reconstruction

    PubMed Central

    Taradaj, J.; Halski, T.; Kucharzewski, M.; Walewicz, K.; Smykla, A.; Ozon, M.; Slupska, L.; Dymarek, R.; Ptaszkowski, K.; Rajfur, J.; Pasternok, M.

    2013-01-01

    The aim of this study was to assess the clinical efficacy and safety of NMES program applied in male soccer players (after ACL reconstruction) on the quadriceps muscle. The 80 participants (NMES = 40, control = 40) received an exercise program, including three sessions weekly. The individuals in NMES group additionally received neuromuscular electrical stimulation procedures on both right and left quadriceps (biphasic symmetric rectangular pulses, frequency of impulses: 2500 Hz, and train of pulses frequency: 50 Hz) three times daily (3 hours of break between treatments), 3 days a week, for one month. The tensometry, muscle circumference, and goniometry pendulum test (follow-up after 1 and 3 months) were applied. The results of this study show that NMES (in presented parameters in experiment) is useful for strengthening the quadriceps muscle in soccer athletes. There is an evidence of the benefit of the NMES in restoring quadriceps muscle mass and strength of soccer players. In our study the neuromuscular electrical stimulation appeared to be safe for biomechanics of knee joint. The pathological changes in knee function were not observed. This trial is registered with Australian and New Zealand Clinical Trials Registry ACTRN12613001168741. PMID:24381943

  2. The effect of neuromuscular electrical stimulation on quadriceps strength and knee function in professional soccer players: return to sport after ACL reconstruction.

    PubMed

    Taradaj, J; Halski, T; Kucharzewski, M; Walewicz, K; Smykla, A; Ozon, M; Slupska, L; Dymarek, R; Ptaszkowski, K; Rajfur, J; Pasternok, M

    2013-01-01

    The aim of this study was to assess the clinical efficacy and safety of NMES program applied in male soccer players (after ACL reconstruction) on the quadriceps muscle. The 80 participants (NMES = 40, control = 40) received an exercise program, including three sessions weekly. The individuals in NMES group additionally received neuromuscular electrical stimulation procedures on both right and left quadriceps (biphasic symmetric rectangular pulses, frequency of impulses: 2500 Hz, and train of pulses frequency: 50 Hz) three times daily (3 hours of break between treatments), 3 days a week, for one month. The tensometry, muscle circumference, and goniometry pendulum test (follow-up after 1 and 3 months) were applied. The results of this study show that NMES (in presented parameters in experiment) is useful for strengthening the quadriceps muscle in soccer athletes. There is an evidence of the benefit of the NMES in restoring quadriceps muscle mass and strength of soccer players. In our study the neuromuscular electrical stimulation appeared to be safe for biomechanics of knee joint. The pathological changes in knee function were not observed. This trial is registered with Australian and New Zealand Clinical Trials Registry ACTRN12613001168741. PMID:24381943

  3. Kinematic Evaluation of the Step-up Exercise in Anterior Cruciate Ligament Deficiency

    PubMed Central

    Kozánek, Michal; Hosseini, Ali; Van de Velde, Samuel K.; Moussa, Mohamed E.; Gill, Thomas J.; Li, Guoan

    2011-01-01

    Background Step-up exercise is one of the most commonly utilized exercises during rehabilitation of patients after both ACL injury and reconstruction. Currently, insurance providers increasingly required a trial of intensified rehabilitation before surgical reconstruction is attempted. The purpose of this study was to investigate whether this “safe” rehabilitation exercise in the setting of ACL deficiency can cause altered knee kinematics. Methods Thirty patients with unilateral ACL rupture were recruited for this study. The mean time from injury was 3.3 months. Tibiofemoral kinematics were determined during a step-up exercise using a combination of MRI, dual fluoroscopy and advanced computer modeling. Findings The ACL-injured knee displayed an average 5° greater external tibial rotation than the uninjured knee (p<0.05), during the last 30% of step-up. The ACL-injured knee also demonstrated on average 2.5 mm greater anterior tibial shift during the last 40% of stance phase (p<0.01). In addition, during the last 30% of stance the tibia of the ACL-deficient knee tended to shift more medially (~1 mm) as the knee approached full extension (p<0.01). Interpertation The data confirmed the initial hypothesis as it was found that ACL deficient knees demonstrated significantly increased anterior tibial translation, medial tibial translation and external tibial rotation towards the end of the step-up as the knee approached full extension. Intensive rehabilitation utilizing the step-up exercise in the setting of ACL deficiency can potentially introduce repetitive microtrauma by way of altered kinematics. PMID:21652128

  4. Objective measures on knee instability: dynamic tests: a review of devices for assessment of dynamic knee laxity through utilization of the pivot shift test.

    PubMed

    Sundemo, David; Alentorn-Geli, Eduard; Hoshino, Yuichi; Musahl, Volker; Karlsson, Jón; Samuelsson, Kristian

    2016-06-01

    Current reconstructive methods used after anterior cruciate ligament (ACL) injury do not entirely restore native knee kinematics. Evaluation of dynamic knee laxity is important to accurately diagnose ACL deficiency, to evaluate reconstructive techniques, and to construct treatment algorithms for patients with ACL injury. The purpose of this study is to present recent progress in evaluation of dynamic knee laxity through utilization of the pivot shift test. A thorough electronic search was performed and relevant studies were assessed. Certain dynamic knee laxity measurement methods have been present for over 10 years (Navigation system, Electromagnetic sensor system) while other methods (Inertial sensor, Image analysis system) have been introduced recently. Methods to evaluate dynamic knee laxity through the pivot shift test are already potent. However, further refinement is warranted. In addition, to correctly quantify the pivot shift test, the involved forces need to be controlled through either standardization or mechanization of the pivot shift test. PMID:26984465

  5. Timing Sequence of Multi-Planar Knee Kinematics Revealed by Physiologic Cadaveric Simulation of Landing: Implications for ACL Injury Mechanism

    PubMed Central

    Kiapour, Ata M.; Quatman, Carmen E.; Goel, Vijay K.; Wordeman, Samuel C.; Hewett, Timothy E.; Demetropoulos, Constantine K.

    2013-01-01

    Background Challenges in accurate, in vivo quantification of multi-planar knee kinematics and relevant timing sequence during high-risk injurious tasks pose challenges in understanding the relative contributions of joint loads in non-contact injury mechanisms. Biomechanical testing on human cadaveric tissue, if properly designed, offers a practical means to evaluate joint biomechanics and injury mechanisms. This study seeks to investigate detailed interactions between tibiofemoral joint multi-planar kinematics and anterior cruciate ligament strain in a cadaveric model of landing using a validated physiologic drop-stand apparatus. Methods Sixteen instrumented cadaveric legs, 45(SD 7) years (8 female and 8 male) were tested. Event timing sequence, change in tibiofemoral kinematics (position, angular velocity and linear acceleration) and change in anterior cruciate ligament strain were quantified. Findings The proposed cadaveric model demonstrated similar tibiofemoral kinematics/kinetics as reported measurements obtained from in vivo studies. While knee flexion, anterior tibial translation, knee abduction and increased anterior cruciate ligament strain initiated and reached maximum values almost simultaneously, internal tibial rotation initiated and peaked (p<0.015 for all comparisons) significantly later. Further, internal tibial rotation reached 1.8(SD 2.5)°, almost 63% of its maximum value, at the time that peak anterior cruciate ligament strain occurred, while both anterior tibial translation and knee abduction had already reached their peaks. Interpretation Together, these findings indicate that although internal tibial rotation contributes to increased anterior cruciate ligament strain, it is secondary to knee abduction and anterior tibial translation in its effect on anterior cruciate ligament strain and potential risk of injury. PMID:24238957

  6. Reducing the Risk of ACL Injury in Female Athletes

    ERIC Educational Resources Information Center

    McDaniel, Larry W.; Rasche, Adrienna; Gaudet, Laura; Jackson, Allen

    2010-01-01

    The Anterior Cruciate Ligament (ACL) is located behind the kneecap (patella) and connects the thigh bone (femur) to the shin bone (tibia). Stabilizing the knee joint is the primary responsibility of the ACL. Injuries that affect the ACL are three to five times more common in females than males. This is a result of anatomical, biomechanical,…

  7. Knee arthroscopy

    MedlinePlus

    ... is cartilage that cushions the space between the bones in the knee. Surgery is done to repair or remove it. Torn or damaged anterior cruciate ligament (ACL) or posterior cruciate ligament (PCL) Torn or damaged collateral ligament Swollen (inflamed) or ...

  8. ACL reconstruction

    MedlinePlus

    ... Tissue taken from a donor is called an allograft. The procedure is usually performed with the help ... This increases the chance you may have a meniscus tear. ACL reconstruction may be used for these ...

  9. ACL reconstruction

    MedlinePlus

    ... replace your ACL by following these steps: The torn ligament will be removed with a shaver or ... ligaments are also injured When your meniscus is torn Before surgery, talk to your health care provider ...

  10. Vitamin K deficiency is associated with incident knee osteoarthritis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Osteoarthritis is the most common form of arthritis, with knee osteoarthritis being the leading cause of lower extremity disability among older adults in the US. There are no treatments available to prevent the structural pathology of osteoarthritis. Because of vitamin K’s role in regulating skeleta...

  11. ACL Roof Impingement Revisited

    PubMed Central

    Tanksley, John Anthony; Conte, Evan J.; Werner, Brian C.; Gwathmey, Frank Winston; Brockmeier, Stephen F.; Miller, Mark D.

    2015-01-01

    Objectives: Anatomic femoral tunnel placement for single-bundle ACL reconstruction is now well accepted. The ideal location for the tibial tunnel, however, has not been studied extensively. A wide range of anterior to posterior (A-P) tibial tunnel locations are considered acceptable. Biomechanical data suggests that the anterior fibers of the native ACL are more functional. Similarly, ACL grafts placed more anteriorly in the footprint have resulted in improved clinical results in at least one study. However, the concern for intercondylar roof impingement has tempered enthusiasm for a more anterior tibial tunnel placement. Investigations by Howell and others on roof impingement have focused only on the transtibial technique. Our study seeks to characterize intercondylar roof impingement in a 3-D cadaveric model with both transtibial and independent femoral tunnel drilling techniques in the setting of an anteriorly positioned tibial tunnel. Methods: Twelve fresh frozen cadaver knees (six matched pairs) were randomized to either a transtibial or an independent femoral (IF) drilling technique. Tibial guide pins were placed in the anterior half of the ACL tibial footprint following arthroscopic debridement of the native ACL. A fluoroscopic calculation of the tibial guide pin location using the technique described by Staubli was used to ensure a relatively anterior position of the tibial tunnel (Staubli < 35). All efforts were made to place the femoral tunnel anatomically in the center of the footprint. An 8 mm Gore-Tex smoother was passed into the knee to function as a radiopaque surrogate graft, and the knees then underwent computed tomography in maximal extension. Graft-visualized 3D-CT reformatting was used to evaluate for roof impingement by analyzing the Impingement Review Index (IRI) as described by Iriuchishima. Tunnel morphology, knee flexion, and intra-articular graft angles were also recorded. Results: Two grafts (2/6, 33.3 %) in the TT group impinged upon the

  12. Double bundle or single bundle plus extraarticular tenodesis in ACL reconstruction? A CAOS study.

    PubMed

    Monaco, E; Labianca, L; Conteduca, F; De Carli, A; Ferretti, A

    2007-10-01

    Anatomic reconstructions of anterior cruciate ligament (ACL) with double bundle gracilis and semitendonosus tendons graft, reproducing AM and PL bundles, have been introduced to offer a better biomechanical outcome, especially during rotatory loads. On the other hand, many methods of tenodesing the lateral aspect of the tibia to the femur to reduce internal rotation (IR) of the tibia and minimize anterior translation of the tibia relative to the femur as a backup for intra-articular reconstruction, have been also suggested. The goal of this study is to evaluate the effect, on the IR of the tibia, of a lateral reconstruction in addition to a standard single bundle ACL reconstruction as compared with an anatomic double bundle ACL reconstruction. Computer assisted ACL reconstruction has been used because it could be very effective in evaluating the global kinematic performance of the reconstructed knee. We selected 20 consecutive ACL reconstruction procedures to be performed in males in our hospital. Patients were alternately assigned to one of the two groups--group A: standard single bundle ACL reconstruction with doubled gracilis and semitendinosus tendons graft with an arthroscopically assisted two incisions technique and a lateral extraarticular reconstruction; group B: double bundle ACL reconstruction with doubled gracilis and semitendinosus tendons graft with an arthroscopically assisted two incisions technique. In all ACL reconstruction procedures navigation process was performed. Both surgical techniques reduced significantly AP displacement, IR and external rotation (ER) of the tibia respect to pre-operative ACL deficient condition (p<0.05). Comparing the group A after the single bundle reconstruction and the group B after the AM bundle fixation, non differences were found in AP displacement, IR and ER of the tibia (p=0.75, p=0.07 and p=0.07 respectively; power: 0.94). Comparing the group A after the addition of the lateral tenodesis and group B after the PL

  13. [Surgical technique: reconstruction of deficient extensor apparatus of the knee - a case report].

    PubMed

    Wilken, F; Harrasser, N; Pohlig, F; Laux, F M; von Eisenhart-Rothe, R

    2015-04-01

    Injuries to the extensor apparatus of the knee are a rare but in case of their occurrence a serious injury. In the following discussion, the focus is on treatment of chronic patellar tendon tears. The aim of surgical treatment is the recovery of the active extension and full weight-bearing ability of the leg. The video presentation shows the operative treatment of a patient with a chronic extensor mechanism deficiency of the knee after multiple revision of a total knee arthroplasty due to periprosthetic infection and three-times occurrence of a patella tendon tear. A frame-shaped reinforcement between patella and tibial tuberosity by FiberTape® combined with a medial gastrocnemius flap was performed. This type of surgery is indicated in cases of large defects of the patellar tendon that cannot be treated with end-to-end suture or simple augmentation with autologous tendons (e.g. semitendinosus). In addition to augmentation of the tendon defect, cutaneous soft tissue defects around the knee and proximal lower leg can be covered. In general, the best treatment option is chosen according to size of the defect, the quality of the tendon tissue and possible previous surgery on the knee joint. There are no reports of large series of chronic patella tendon tears, but only isolated cases using a variety of techniques. In addition with low level of evidence, there is currently no established gold standard in the surgical treatment of insufficiencies of the extensor apparatus of the knee. PMID:25874403

  14. ACL reconstruction - discharge

    MedlinePlus

    Anterior cruciate ligament reconstruction - discharge; ACL reconstruction - discharge ... had surgery to reconstruct your anterior cruciate ligament (ACL). The surgeon drilled holes in the bones of ...

  15. Repaired ACL More Likely to Tear Again in Young Women

    MedlinePlus

    ... a repeat tear of the knee's anterior cruciate ligament (ACL) after surgery to repair it, a new ... 7 at the society's annual meeting in Colorado Springs, Colo. Research presented at medical meetings is typically ...

  16. Validation of predicted patellofemoral mechanics in a finite element model of the healthy and cruciate-deficient knee.

    PubMed

    Ali, Azhar A; Shalhoub, Sami S; Cyr, Adam J; Fitzpatrick, Clare K; Maletsky, Lorin P; Rullkoetter, Paul J; Shelburne, Kevin B

    2016-01-25

    Healthy patellofemoral (PF) joint mechanics are critical to optimal function of the knee joint. Patellar maltracking may lead to large joint reaction loads and high stresses on the articular cartilage, increasing the risk of cartilage wear and the onset of osteoarthritis. While the mechanical sources of PF joint dysfunction are not well understood, links have been established between PF tracking and abnormal kinematics of the tibiofemoral (TF) joint, specifically following cruciate ligament injury and repair. The objective of this study was to create a validated finite element (FE) representation of the PF joint in order to predict PF kinematics and quadriceps force across healthy and pathological specimens. Measurements from a series of dynamic in-vitro cadaveric experiments were used to develop finite element models of the knee for three specimens. Specimens were loaded under intact, ACL-resected and both ACL and PCL-resected conditions. Finite element models of each specimen were constructed and calibrated to the outputs of the intact knee condition, and subsequently used to predict PF kinematics, contact mechanics, quadriceps force, patellar tendon moment arm and patellar tendon angle of the cruciate resected conditions. Model results for the intact and cruciate resected trials successfully matched experimental kinematics (avg. RMSE 4.0°, 3.1mm) and peak quadriceps forces (avg. difference 5.6%). Cruciate resections demonstrated either increased patellar tendon loads or increased joint reaction forces. The current study advances the standard for evaluation of PF mechanics through direct validation of cruciate-resected conditions including specimen-specific representations of PF anatomy. PMID:26742720

  17. Knee arthroscopy - discharge

    MedlinePlus

    ... is cartilage that cushions the space between the bones in the knee. Surgery is done to repair or remove it. Torn or damaged anterior cruciate ligament (ACL) or posterior cruciate ligament (PCL) Inflamed or damaged lining of the joint. This ...

  18. Knee arthroscopy - discharge

    MedlinePlus

    ... knee arthroscopy). You may have been checked for: Torn meniscus. Meniscus is cartilage that cushions the space ... Surgery is done to repair or remove it. Torn or damaged anterior cruciate ligament (ACL) or posterior ...

  19. Update on rehabilitation following ACL reconstruction

    PubMed Central

    Nyland, John; Brand, Emily; Fisher, Brent

    2010-01-01

    As anterior cruciate ligament (ACL) reconstruction has evolved to less invasive, more anatomical approaches, rehabilitation of the injured athlete has likewise become more progressive and innovative, with a sound understanding of graft and fixation strength and biologic healing-remodeling constraints. This review discusses these innovations including specific considerations before surgery, when planning rehabilitation timetables, and the importance of reestablishing nonimpaired active and passive knee range of motion and biarticular musculotendinous extensibility in positions of function. Concepts of self-efficacy or confidence and reestablishing the “athlete role” are also addressed. Since ACL injury and reinjury are largely related to the influence of structure-form-function on dynamic knee joint stability, the interrelationships between sensorimotor, neuromuscular, and conventional resistance training are also discussed. Although pivot shift “giving way” relates to function loss following ACL injury, anterior translational laxity often does not. Although there is growing evidence that progressive eccentric training may benefit the patient following ACL reconstruction, there is less evidence supporting the use of functional ACL knee braces. Of considerable importance is selecting and achieving a criteria-based progression to sports-specific training, reestablishing osseous homeostasis and improved bone density, blending open and closed kinetic chain exercises at the appropriate time period, and appreciating the influence of the trunk, upper extremities, and sports equipment use on knee loads. We believe that knee dysfunction and functional recovery should be considered from a local, regional, and global perspective. These concepts are consolidated into our approach to prepare patients for return to play including field testing and maintenance training. PMID:24198553

  20. Greater fear of re-injury and increased tibial translation in patients who later sustain an ACL graft rupture or a contralateral ACL rupture: a pilot study.

    PubMed

    Tagesson, Sofi; Kvist, Joanna

    2016-01-01

    The aim was to compare fear of re-injury, patient reported function, static and dynamic tibial translation and muscle strength assessed before and 5 weeks after an anterior cruciate ligament (ACL) reconstruction between individuals who sustained a subsequent ACL graft rupture or a contralateral ACL injury within 5 years after the reconstruction, and individuals with no subsequent injury. Nineteen patients were investigated before, and 5 weeks after an ACL reconstruction with a quadruple hamstring tendon graft. At 5 years follow up, 3 patients had sustained an ACL graft rupture and 2 patients had sustained a contralateral ACL rupture. Fear of re-injury, confidence with the knee, patient reported function, activity level, static and dynamic tibial translation and muscle strength were assessed. The re-injured group reported greater fear of re-injury and had greater static tibial translation in both knees before the ACL reconstruction compared to those who did not sustain another ACL injury. There were no other differences between groups. In conclusion, fear of re-injury and static tibial translation before the index ACL reconstruction were greater in patients who later on suffered an ACL graft rupture or a contralateral ACL rupture. These factors may predict a subsequent ACL injury. PMID:25894209

  1. Mid-term clinical results of medial meniscus repair with the meniscus arrow in the unstable knee.

    PubMed

    Koukoulias, Nikolaos; Papastergiou, Stergios; Kazakos, Konstantinos; Poulios, Georgios; Parisis, Konstantinos

    2007-02-01

    The medial meniscus is a secondary stabilizer to anterior tibial translation and provides significant stability, especially in an ACL-deficient knee. The purpose of this study is to evaluate the clinical outcome of medial meniscus repair in the unstable knee. Between 1997 and 2002, 11 patients, with a mean age of 25.8 years (range 15-39 years), underwent all-inside medial meniscus repair, using the Meniscus Arrow, for unstable medial meniscus tear in ACL-deficient knees. For various reasons none of these patients underwent ACL reconstruction. The average follow-up was 73 months (range 52-91 months). There were three failures (27.3%) defined as the need for reoperation and partial meniscectomy. The mean Tegner activity score decreased from 6.75 (pretrauma) to 4.5 (postoperatively). The average Lysholm and subjective IKDC scores were 83 and 77.4, respectively. Two patients were graded as B (nearly normal) and six as C (abnormal), according to the IKDC knee evaluation form. KT-2000 arthrometry demonstrated that sagittal knee laxity was more than 5 mm in all knees (side to side difference). MRI demonstrated grade three signal alterations at the repair site of meniscus in three patients and signs of cartilage damage in two patients. All patients were asymptomatic during daily activities but seven out of eight reported pain or effusion after sports. Medial meniscus repair in the ACL-deficient knee is not contraindicated. The need of reducing the level of physical activity is essential. PMID:16967201

  2. Results of revision total knee arthroplasty in the face of significant bone deficiency.

    PubMed

    Rorabeck, C H; Smith, P N

    1998-04-01

    The successful approach to the failed knee with bone deficiency is dependent upon thorough planning prior to surgery in order to have the resources available in terms of adequate bone allograft and suitable revision implants. The approximate size of bone stock deficiency can be calculated from preoperative radiographs and similarly ligamentous incompetence can often be diagnosed clinically prior to surgery. Smaller defects of up to 1 to 1.5 cm in depth and localized in the main to a single side of the tibial plateau or to a single femoral condyle can be dealt with using smaller grafts that may be local autograft or allograft, or modular wedges. Larger tibial defects can be compensated for using conventional revision systems by thicker polyethylene and augmented baseplates, but once the flexion-extension gap reaches approximately 40 mm this is no longer possible and structural graft or customized componentry becomes necessary. Femoral defects larger than about 1 cm that cannot be made up by augments necessitate grafting. The need to use a large proximal tibial allograft also may dictate the operative approach used to expose the joint, especially in the situation of a multiply-operated tight knee. In such cases the use of a quadriceps turndown may be more advisable than the use of a tibial tubercle osteotomy as the osteotomy may well not have an adequate bed to heal to following the reconstruction. Several series have reported cases of patellar tendon avulsion and the clinical results following this complication usually are not satisfactory. Preoperatively it is important to identify, if possible, the case that is likely to require a more extended approach because of a tight soft tissue envelope. The reports of results of series of revision total knee arthroplasty in the setting of significant bone loss are at present confined to short-term followup. The clinical results of these series are satisfactory at this early point in time, but decision regarding the

  3. Influence of increasing construct constraint in the presence of posterolateral deficiency at knee replacement: A biomechanical study.

    PubMed

    Ghosh, Kanishka M; Manning, William A; Blain, Alasdair P; Rushton, Steve P; Longstaff, Lee M; Amis, Andrew A; Deehan, David J

    2016-03-01

    When faced with posterolateral corner (PLC) deficiency, surgeons must choose a total knee replacement (TKR) construct that provides the appropriate level of constraint. This should match the internal constraint of the device to the soft tissue host laxity pattern. Little guidance is available peroperatively, with factors influencing final component choice remaining ill defined. This study aimed to quantify the effect of PLC insufficiency on the "envelope of laxity" (EoL) after TKR and the effect of increasingly component constraint upon knee behavior through a functional arc of flexion. Using computer navigation, mixed effect modeling and loaded cadaveric legs--laxity was quantified under separate states: the native knee, after implantation of a posterior stabilized (PS)-TKR, after sectioning the lateral (fibular) collateral ligament and popliteus tendon (PS-TKR-PLC), and after re-implantation with a semi-constrained "total stabilized" knee replacement (TS-TKR). Laxity was quantified from 0 to 110° of flexion for anterior draw, varus-valgus, and internal-external rotation. Implantation of the PS-TKR was consistently associated with increased constraint when compared to the native knee. PLC sectioning led to significantly increased laxity during varus stress from mid to deep flexion. Revision to a TS-TKR construct restored constraint mimicking that of the primary state but only for the arc of motion 0-90°. In a posterolateral deficient state, a fixed bearing semi-constrained TS-TKR restored the knee to near normal kinematics but this was only achieved from an arc of motion 0-90° of flexion. At higher flexion angles, there remained an unfavorable laxity pattern with varus stress opening. PMID:26267425

  4. Evaluation of the Microsoft Kinect for screening ACL injury.

    PubMed

    Stone, Erik E; Butler, Michael; McRuer, Aaron; Gray, Aaron; Marks, Jeffrey; Skubic, Marjorie

    2013-01-01

    A study was conducted to evaluate the use of the skeletal model generated by the Microsoft Kinect SDK in capturing four biomechanical measures during the Drop Vertical Jump test. These measures, which include: knee valgus motion from initial contact to peak flexion, frontal plane knee angle at initial contact, frontal plane knee angle at peak flexion, and knee-to-ankle separation ratio at peak flexion, have proven to be useful in screening for future knee anterior cruciate ligament (ACL) injuries among female athletes. A marker-based Vicon motion capture system was used for ground truth. Results indicate that the Kinect skeletal model likely has acceptable accuracy for use as part of a screening tool to identify elevated risk for ACL injury. PMID:24110646

  5. Consistency of strength curves for determining maximal effort production during isokinetic knee testing of anterior cruciate ligament-deficient patients.

    PubMed

    Almosnino, Sivan; Dvir, Zeevi; Bardana, Davide D

    2016-04-01

    The purpose of this investigation was to attempt to establish decision rules for determining maximal effort production during isokinetic strength testing of unilateral anterior cruciate ligament-deficient patients based on the degree of strength curve consistency within a set. Thirty-three participants performed six bilateral knee extension and flexion exertions at maximal effort and at 80% of perceived maximum at testing velocities of 60 and 180°s(-1). Within-set consistency was quantified by computation of the variance ratio across strength curves. Tolerance interval-based cutoff scores covering 99% of the population were calculated for declaring efforts as being maximal or not at confidence levels of 90%, 95%, and 99%. The sensitivity percentages attained for the injured knee for both testing velocities ranged between 9.1% and 27.2%, while specificity percentages ranged between 84.8% and 100%. For the non-injured knee, sensitivity values for both testing velocities ranged between 21.2% and 45.0%, while specificity percentages ranged between 97.0% and 100%. The developed decision rules do not effectively discriminate on an individual patient basis between maximal and non-maximal isokinetic knee musculature efforts. Further research is needed for development of methods that would enable to ascertain maximal effort production in this patient population during knee muscle strength testing. PMID:27043046

  6. Gait modification strategies in trunk over right stance phase in patients with right anterior cruciate ligament deficiency.

    PubMed

    Shi, Dongliang; Li, Nannan; Wang, Yubin; Jiang, Shuyun; Lin, Jianping; Zhu, Wenhui

    2016-05-01

    This study aimed to investigate the gait modification strategies of trunk over right stance phase in patients with right anterior cruciate ligament deficiency (ACL-D). Thirty-six patients with right chronic ACL-D were recruited, as well as 36 controls. A 3D optical video motion capture system was used during gait and stair ambulation. Kinematic variables of the trunk and kinematic and kinetic variables of the knee were calculated. Patients with chronic right ACL-D exhibited many significant abnormalities compared with controls. Trunk rotation with right shoulder trailing over the right stance phase was lower in all five motion patterns (P<0.05). Compared with controls, trunk posterior lean was higher from descending stairs to walking when the knee sagittal plane moment ended (P<0.01). Trunk lateral flexion to the left was higher when ascending stairs at the start of right knee coronal plane moment (P=0.01), when descending stairs at the maximal knee coronal plane moment (P<0.01), and when descending stairs at the end of the knee coronal plane moment (P=0.03). Trunk rotation with right shoulder forward was higher at the minimal knee transverse plane moment (P<0.01) and when the knee transverse plane moment ended (P<0.01); during walking, trunk rotation with right shoulder trailing was lower at other knee moments during other walking patterns (all P<0.01). In conclusion, gait modification strategies of the trunk were apparent in patients with ACL-D. These results provide new insights about diagnosis and rehabilitation of chronic ACL-D (better use of walking and stair tasks as part of a rehabilitation program). PMID:27131179

  7. Dual ACL Ganglion Cysts: Significance of Detailed Arthroscopy

    PubMed Central

    Singla, Amit; Nag, H. L.; Meena, Sanjay; Lohiya, Ramprakash; Agarwal, Abhinav

    2014-01-01

    Intra-articular ganglion cysts of the knee joint are rare and most frequently are an incidental finding on MRI and arthroscopy. Most of the previous studies have reported a single ganglion cyst in the knee. There have been previous reports of more than one cyst in the same knee but not in the same structure within the knee. We are reporting a case of dual ACL (anterior cruciate ligament) ganglion cysts one of which was missed on radiological examination but later detected during arthroscopy. To the best of our knowledge, no such case has been reported in the indexed English literature till date. PMID:25400962

  8. Preferential Loading of the ACL Compared With the MCL During Landing

    PubMed Central

    Quatman, Carmen E.; Kiapour, Ata M.; Demetropoulos, Constantine K.; Kiapour, Ali; Wordeman, Samuel C.; Levine, Jason W.; Goel, Vijay K.; Hewett, Timothy E.

    2014-01-01

    Background Strong biomechanical and epidemiological evidence associates knee valgus collapse with isolated, noncontact anterior cruciate ligament (ACL) injuries. However, a concomitant injury to the medial collateral ligament (MCL) would be expected under valgus collapse, based on the MCL’s anatomic orientation and biomechanical role in knee stability. Purpose/Hypothesis The purpose of this study was to investigate the relative ACL to MCL strain patterns during physiological simulations of a wide range of high-risk dynamic landing scenarios. We hypothesized that both knee abduction and internal tibial rotation moments would generate a disproportionate increase in the ACL strain relative to the MCL strain. However, the physiological range of knee abduction and internal tibial rotation moments that produce ACL injuries are not of sufficient magnitude to compromise the MCL’s integrity consistently. Study Design Controlled laboratory study. Methods A novel in sim approach was used to test our hypothesis. Seventeen cadaveric lower extremities (mean age, 45 ± 7 years; 9 female and 8 male) were tested to simulate a broad range of landings after a jump under anterior tibial shear force, knee abduction, and internal tibial rotation at 25° of knee flexion. The ACL and MCL strains were quantified using differential variable reluctance transducers. An extensively validated, detailed finite element model of the lower extremity was used to help better interpret experimental findings. Results Anterior cruciate ligament failure occurred in 15 of 17 specimens (88%). Increased anterior tibial shear force and knee abduction and internal tibial rotation moments resulted in significantly higher ACL:MCL strain ratios (P < .05). Under all modes of single-planar and multiplanar loading, the ACL:MCL strain ratio remained greater than 1.7, while the relative ACL strain was significantly higher than the relative MCL strain (P < .01). Relative change in the ACL strain was demonstrated

  9. Bridge-Enhanced ACL Repair: A Review of the Science and the Pathway through FDA Investigational Device Approval

    PubMed Central

    Proffen, Benedikt L.; Perrone, Gabriel S.; Roberts, Gordon; Murray, Martha M.

    2016-01-01

    Injuries to the anterior cruciate ligament (ACL) are currently treated with replacement of the torn ligament with a graft of tendon harvested from elsewhere in the knee. This procedure, called "ACL reconstruction," is excellent for restoring gross stability to the knee; however, there are relatively high graft failure rates in adolescent patients,4, 12, 60 and the ACL reconstruction procedure does not prevent the premature osteoarthritis seen in patients after an ACL injury.1, 46, 52 Thus, new solutions are needed for ACL injuries. Researchers have been investigating the use of scaffolds, growth factors and cells to supplement a suture repair of the ACL (bio-enhanced repair). In this paper, we will review the varied approaches, which have been investigated for stimulating ACL healing and repair in preclinical models and how one of these technologies was able to move from promising preclinical results to FDA acceptance of an Investigational Device Exemption (IDE) application for a first-in-human study. PMID:25631206

  10. PROPRIOCEPTION, BODY BALANCE AND FUNCTIONALITY IN INDIVIDUALS WITH ACL RECONSTRUCTION

    PubMed Central

    Furlanetto, Tássia Silveira; Peyré-Tartaruga, Leonardo Alexandre; do Pinho, Alexandre Severo; Bernardes, Emanuele da Silva; Zaro, Milton Antonio

    2016-01-01

    Objective : To evaluate and compare proprioception, body balance and knee functionality of individuals with or without unilateral anterior cruciate ligament (ACL) reconstruction. Methods : Forty individuals were divided in two groups: Experimental group, 20 individuals with ACL reconstruction at six months postoperative, and control group, 20 individuals with no history of lower limb pathologies. In the experimental group, we assessed lower limbs with reconstructed ACL and contralateral limb; in the control group the dominant and the non-dominant lower limbs were assessed. All subjects were submitted to joint position sense test to evaluate proprioception, postural control measure in single-limb, and step up and down (SUD) test for functional assessment. Results : There were no deficits in proprioception and postural control. In the SUD test, a 5% decrease in lift up force was found in reconstructed ACL lower limbs, however, a statistically not significant difference. The impact and step down force during the course of test were 30% greater in anatomic ACL than in control lower limbs. Conclusion : The individuals with ACL reconstruction at six months postoperative did not show changes in proprioception and postural control, but showed motor control changes, influencing knee functionality. Level of Evidence IV, Prognostic Studies. PMID:26981038

  11. Editorial Commentary: Knee Lateral Extra-articular Tenodesis.

    PubMed

    Lubowitz, James H

    2015-10-01

    Knee lateral extra-articular tenodesis (LET) can be combined with anterior cruciate ligament (ACL) reconstruction with a goal of reducing anterolateral rotatory instability. Like double-bundle ACL reconstruction, LET combined with ACL reconstruction reduces pivot-shift, a subjective test, but results in no significant difference in clinical outcome. PMID:26433239

  12. Body Mass Index, Modulated by Lateral Posterior Tibial Slope, Predicts ACL Injury Risk

    PubMed Central

    Bojicic, Katherine M.; Beaulieu, Melanie L.; Krieger, Daniel Imaizumi; Ashton-Miller, James A.; Wojtys, Edward M.

    2016-01-01

    Objectives: Intervention strategies to prevent ACL injury rely on increasing knowledge of risk factors. While several modifiable and non-modifiable risk factors for ACL rupture have been identified, the interaction between them remains unknown. The aim of this study was to quantify the relationship between BMI and several knee geometries as potential risk factors for ACL injury. We hypothesized that an increased BMI in the presence of an increased posterior tibial slope or middle cartilage slope would increase risk of ACL injury. We also hypothesized that an increased BMI in the presence of a decreased posterior meniscal height or meniscal bone angle would result in an increased risk of ACL injury. Methods: Sagittal knee MRI files from 76 ACL-injured and 42 non-injured subjects were gathered from the institution’s archive. The PTS, MCS, PMH, and MBA were measured using the circle method and compared with BMI from the subject demographic. Data were analyzed using univariate and multivariate logistical regression. Figure 1 details measurements made for each knee geometry. Results: Univariate analysis of PTS showed increases in PTS significantly increase the odds of ACL tear (p = 0.043, OR =1.12). Univariate analysis of MCS showed increases of MCS significantly increase the odds of ACL tear (p = 0.037, OR = 1.12). Multivariate analysis of PTS and BMI centered around the mean (PTS*cBMI) showed increases of PTS in combination with increases in cBMI significantly increases the odds of ACL rupture (p value = .050, OR = 1.03). Table 1 shows predicted increases in ACL injury risk for combinations of increases in PTS and BMI. Conclusion: An increase in BMI will increase the risk of ACL tear when an increase in lateral posterior tibial slope is present. An increase in lateral posterior tibial slope or lateral middle cartilage slope increases the risk of an ACL tear.

  13. Transtibial Versus Anteromedial Portal ACL Reconstruction

    PubMed Central

    Jennings, Jonathan Kelsie; Leas, Daniel; Fleischli, James E.; D’Alessandro, Donald; Peindl, Richard Dennis; Habet, Nahir A.; Piasecki, Dana P.

    2016-01-01

    Objectives: A number of studies suggest improved biomechanical and clinical results when ACL grafts are placed anatomically. Worldwide, the most common transtibial (TT) technique has been shown less anatomic than an anteromedial portal (AM) technique, though is much more familiar and less technically challenging. A hybrid transtibial approach (HTT) - using AM portal guidance of a flexible transtibial guide wire without knee hyperflexion - may offer anatomic graft placement while maintaining the relative ease of a transtibial technique. Our objective is to evaluate the anatomic and biomechanical performance of HTT, when compared to TT and AM approaches. Methods: A total of 36 paired, fresh-frozen human knees were used. 24 knees (12 pairs) - each using a standard tibial tunnel - underwent all three techniques (TT, AM, HTT) for femoral tunnel placement, with direct measurement of femoral insertional overlap and femoral tunnel length for each technique. The remaining 12 knees (6 pairs) were used to evaluate graft kinematics and tunnel orientation. Among these knees, 3 size-matched groups (four specimens each) were assigned to each of TT, AM and HTT techniques. Specimens were tested in quad-load induced extension from 90o to 10o of flexion with a distal weight used to simulate half-shank, ankle and foot passive load. Bony kinematics were assessed using a trakSTAR motion tracking system with three sensors installed in each femur and tibia. After femoral tunnel preparation, two sensors were installed in each tunnel to relate tunnel orientation and tunnel inlet location within the joint to the sensors used for motion tracking for the femur and tibia of each specimen. Bone-patellar-bone autografts were harvested from each specimen and used for the assigned reconstructive technique. Analysis included determination of ACL graft length changes, ACL-to-femoral tunnel angle and ACL-to-tibial tunnel angle at five flex/ext angles. Data was analyzed for three flex/ext tests on each

  14. Knee extension and flexion: MR delineation of normal and torn anterior cruciate ligaments

    SciTech Connect

    Niitsu, Mamoru; Ikeda, Kotaroh; Fukubayashi, Tohru; Anno, Izumi; Itai, Yuji

    1996-03-01

    Our goal was to assess the effect of joint position of semiflexed and extended knees in MR delineation of the anterior cruciate ligament (ACL). With a mobile knee brace and a flexible surface coil, the knee joint was either fully extended or bent to a semiflexed position (average 45{degrees} of flexion) within the magnet bore. Sets of oblique sagittal MR images were obtained for both extended and flexed knee positions. Thirty-two knees with intact ACLs and 43 knees with arthroscopically proven ACL tears were evaluated. Two observers compared paired MR images of both extended and flexed positions and rated them by a relative three point scale. Anatomic correlation in MR images was obtained by a cadaveric knee with incremental flexion. The MR images of flexed knees were more useful than of extended knees in 53% of the case reviews of femoral attachments and 36% of reviews of midportions of normal ACLs. Compared with knee extensions, the MR images for knee flexion provided better clarity in 48% of reviews of disrupted sites and 52% of residual bundles of torn ACLs. Normal ACL appeared taut in the knee extension and lax in semiflexion. Compared with MR images of knees in extension, MR images of knees in flexion more clearly delineate the femoral side of the ligament with wider space under the intercondylar roof and with decreased volume-averaging artifacts, providing superior visualization of normal and torn ACLs. 13 refs., 7 figs., 1 tab.

  15. The effect of isolated valgus moments on ACL strain during single-leg landing: A simulation study

    PubMed Central

    Shin, Choongsoo S.; Chaudhari, Ajit M.; Andriacchi, Thomas P.

    2009-01-01

    Valgus moments on the knee joint during single-leg landing have been suggested as a risk factor for anterior cruciate ligament (ACL) injury. The purpose of this study was to test the influence of isolated valgus moment on ACL strain during single-leg landing. Physiologic levels of valgus moments from an in vivo study of single-leg landing were applied to a three-dimensional dynamic knee model, previously developed and tested for ACL strain measurement during simulated landing. The ACL strain, knee valgus angle, tibial rotation, and medial collateral ligament (MCL) strain were calculated and analyzed. The study shows that the peak ACL strain increased nonlinearly with increasing peak valgus moment. Subjects with naturally high valgus moments showed greater sensitivity for increased ACL strain with increased valgus moment, but ACL strain plateaus below reported ACL failure levels when the applied isolated valgus moment rises above the maximum values observed during normal cutting activities. In addition, the tibia was observed to rotate externally as the peak valgus moment increased due to bony and soft-tissue constraints. In conclusion, knee valgus moment increases peak ACL strain during single-leg landing. However, valgus moment alone may not be sufficient to induce an isolated ACL tear without concomitant damage to the MCL, because coupled tibial external rotation and increasing strain in the MCL prevent proportional increases in ACL strain at higher levels of valgus moment. Training that reduces the external valgus moment, however, can reduce the ACL strain and thus may help athletes reduce their overall ACL injury risk. PMID:19100550

  16. Through-knee amputation for a patient with proximal femur focal deficiency and tibial hemimelia: surgical anatomy and clinical implications.

    PubMed

    Lloyd, Selvyn; Rashid, Abdul Halim Abd; Das, Srijit; Ibrahim, Sharaf

    2014-03-01

    Tibial hemimelia is a rare anomaly of unknown etiology. This condition can occur sporadically or may have a familial inheritance. It is characterized by deficiency of the tibia with a relatively intact fibula. The anomaly may be unilateral or bilateral. We report a case of a 2-year-old girl who presented with right lower limb deformity since birth. She was diagnosed with proximal femur focal deficiency with absence of the ipsilateral tibia. She presented with a shorter right lower limb and a deformed foot. She was treated with a through-knee amputation. Anatomical dissection of the amputated limb was carried out to verify the anomalies. The dissection showed that the distal phalanx of the great toe was trifid. The anatomical and clinical significance of this interesting case is discussed. PMID:24158808

  17. Developing a 6-DOF robot to investigate multi-axis ACL injuries under valgus loading coupled with tibia internal rotation.

    PubMed

    Ren, Yupeng; Jacobs, Benjamin J; Nuber, Gordon W; Koh, Jason L; Zhang, Li-Qun

    2010-01-01

    Anterior cruciate ligament (ACL) injuries have become more common in recent years as more young people participate in risky sporting activities [1]. Most ACL injuries occur as a result of noncontact mechanisms. Previous in vitro studies of ACL strain have found significant increases in ACL strain primarily with anterior directed force on the tibia relative to the femur and with internal rotation and often with valgus torque [2,3]. However, there remains significant controversy over the mechanisms of ACL failure and the forces on the knee that lead to injury. Some studies have also shown that isolated valgus loading may not load the ACL strongly. The goal of this study was to investigate the mechanism underlying valgus-related ACL injuries. An improved understanding of ACL failure may lead to improved ACL injury prevention programs. A novel 6 degrees of freedom (DOF) knee driving robot was developed in this study with a unique multi-axis simultaneous torque/position control. It was found that pure valgus torque caused a torque that internally rotated the tibia and thus increased ACL strain markedly, which may be an important mechanism underlying the rather common seemingly valgus-related ACL injuries. PMID:21097089

  18. The Effects of Anterior Cruciate Ligament Deficiency on the Meniscus and Articular Cartilage

    PubMed Central

    Arner, Justin W.; Irvine, James N.; Zheng, Liying; Gale, Tom; Thorhauer, Eric; Hankins, Margaret; Abebe, Ermias; Tashman, Scott; Zhang, Xudong; Harner, Christopher D.

    2016-01-01

    Background: Anterior cruciate ligament (ACL) injury increases the risk of meniscus and articular cartilage damage, but the causes are not well understood. Previous in vitro studies were static, required extensive knee dissection, and likely altered meniscal and cartilage contact due to the insertion of pressure sensing devices. Hypothesis: ACL deficiency will lead to increased translation of the lateral meniscus and increased deformation of the medial meniscus as well as alter cartilage contact location, strain, and area. Study Design: Descriptive laboratory study. Methods: With minimally invasive techniques, six 1.0-mm tantalum beads were implanted into the medial and lateral menisci of 6 fresh-frozen cadaveric knees. Dynamic stereo x-rays (DSXs) were obtained during dynamic knee flexion (from 15° to 60°, simulating a standing squat) with a 46-kg load in intact and ACL-deficient states. Knee kinematics, meniscal movement and deformation, and cartilage contact were compared by novel imaging coregistration. Results: During dynamic knee flexion from 15° to 60°, the tibia translated 2.6 mm (P = .05) more anteriorly, with 2.3° more internal rotation (P = .04) with ACL deficiency. The medial and lateral menisci, respectively, translated posteriorly an additional 0.7 mm (P = .05) and 1.0 mm (P = .03). Medial and lateral compartment cartilage contact location moved posteriorly (2.0 mm [P = .05] and 2.0 mm [P = .04], respectively). Conclusion: The lateral meniscus showed greater translation with ACL deficiency compared with the medial meniscus, which may explain the greater incidences of acute lateral meniscus tears and chronic medial meniscus tears. Furthermore, cartilage contact location moved further posteriorly than that of the meniscus in both compartments, possibly imparting more meniscal stresses that may lead to early degeneration. This new, minimally invasive, dynamic in vitro model allows the study of meniscus function and cartilage contact and can be

  19. An improved OpenSim gait model with multiple degrees of freedom knee joint and knee ligaments.

    PubMed

    Xu, Hang; Bloswick, Donald; Merryweather, Andrew

    2015-08-01

    Musculoskeletal models are widely used to investigate joint kinematics and predict muscle force during gait. However, the knee is usually simplified as a one degree of freedom joint and knee ligaments are neglected. The aim of this study was to develop an OpenSim gait model with enhanced knee structures. The knee joint in this study included three rotations and three translations. The three knee rotations and mediolateral translation were independent, with proximodistal and anteroposterior translations occurring as a function of knee flexion/extension. Ten elastic elements described the geometrical and mechanical properties of the anterior and posterior cruciate ligaments (ACL and PCL), and the medial and lateral collateral ligaments (MCL and LCL). The three independent knee rotations were evaluated using OpenSim to observe ligament function. The results showed that the anterior and posterior bundles of ACL and PCL (aACL, pACL and aPCL, pPCL) intersected during knee flexion. The aACL and pACL mainly provided force during knee flexion and adduction, respectively. The aPCL was slack throughout the range of three knee rotations; however, the pPCL was utilised for knee abduction and internal rotation. The LCL was employed for knee adduction and rotation, but was slack beyond 20° of knee flexion. The MCL bundles were mainly used during knee adduction and external rotation. All these results suggest that the functions of knee ligaments in this model approximated the behaviour of the physical knee and the enhanced knee structures can improve the ability to investigate knee joint biomechanics during various gait activities. PMID:24611807

  20. Stability Outcomes following Computer-Assisted ACL Reconstruction

    PubMed Central

    Christino, Melissa A.; Vopat, Bryan G.; Matson, Andrew P.; Reinert, Steven E.; Shalvoy, Robert M.

    2015-01-01

    Purpose. The purpose of this study was to determine whether intraoperative prereconstruction stability measurements and/or patient characteristics were associated with final knee stability after computer-assisted ACL reconstruction. Methods. This was a retrospective review of all patients who underwent computer-assisted single-bundle ACL reconstruction by a single surgeon. Prereconstruction intraoperative stability measurements were correlated with patient characteristics and postreconstruction stability measurements. 143 patients were included (87 male and 56 female). Average age was 29.8 years (SD ± 11.8). Results. Females were found to have significantly more pre- and postreconstruction internal rotation than males (P < 0.001 and P = 0.001, resp.). Patients with additional intra-articular injuries demonstrated more prereconstruction anterior instability than patients with isolated ACL tears (P < 0.001). After reconstruction, these patients also had higher residual anterior translation (P = 0.01). Among all patients with ACL reconstructions, the percent of correction of anterior translation was found to be significantly higher than the percent of correction for internal or external rotation (P < 0.001). Conclusion. Anterior translation was corrected the most using a single-bundle ACL reconstruction. Females had higher pre- and postoperative internal rotation. Patients with additional injuries had greater original anterior translation and less operative correction of anterior translation compared to patients with isolated ACL tears. PMID:25883804

  1. Non-contact ACL injuries in female athletes: an International Olympic Committee current concepts statement

    PubMed Central

    Renstrom, P; Ljungqvist, A; Arendt, E; Beynnon, B; Fukubayashi, T; Garrett, W; Georgoulis, T; Hewett, T E; Johnson, R; Krosshaug, T; Mandelbaum, B; Micheli, L; Myklebust, G; Roos, E; Roos, H; Schamasch, P; Shultz, S; Werner, S; Wojtys, E; Engebretsen, L

    2014-01-01

    The incidence of anterior cruciate ligament (ACL) injury remains high in young athletes. Because female athletes have a much higher incidence of ACL injuries in sports such as basketball and team handball than male athletes, the IOC Medical Commission invited a multidisciplinary group of ACL expert clinicians and scientists to (1) review current evidence including data from the new Scandinavian ACL registries; (2) critically evaluate high-quality studies of injury mechanics; (3) consider the key elements of successful prevention programmes; (4) summarise clinical management including surgery and conservative management; and (5) identify areas for further research. Risk factors for female athletes suffering ACL injury include: (1) being in the preovulatory phase of the menstrual cycle compared with the postovulatory phase; (2) having decreased intercondylar notch width on plain radiography; and (3) developing increased knee abduction moment (a valgus intersegmental torque) during impact on landing. Well-designed injury prevention programmes reduce the risk of ACL for athletes, particularly women. These programmes attempt to alter dynamic loading of the tibiofemoral joint through neuromuscular and proprioceptive training. They emphasise proper landing and cutting techniques. This includes landing softly on the forefoot and rolling back to the rearfoot, engaging knee and hip flexion and, where possible, landing on two feet. Players are trained to avoid excessive dynamic valgus of the knee and to focus on the “knee over toe position” when cutting. PMID:18539658

  2. The Synergistic Role of the Lateral Meniscus Posterior Root and the ALL in Providing Anterolateral Rotational Stability of the Knee

    PubMed Central

    Getgood, Alan M.; Lording, Timothy; Corbo, Gillian; Burkhart, Tim A.

    2016-01-01

    Objectives: Injury to the anterolateral ligament (ALL) has been reported to contribute to high-grade anterolateral laxity following anterior cruciate ligament (ACL) injury. Failure to address ALL injury has been suggested as a cause of persistent rotational laxity following ACL reconstruction. However, lateral meniscus posterior root (LMPR) tears have also has been shown to cause increased internal rotation and anterior translation of the knee. Due to the anatomic relationship of the ALL and the lateral meniscus, we hypothesize that the ALL and lateral meniscus work synergistically, and that a tear to the LMPR will have the same effect on anterolateral laxity as an ALL tear in the ACL deficient knee. Methods: Sixteen fresh frozen cadaveric knee specimens (mid -femur to mid-tibia) were potted into a hip simulator (femur) and a six degree-of-freedom load cell (tibia). Two rigid optical trackers were inserted into the proximal femur and distal tibia, allowing for the motion of the tibia with respect to the femur to be tracked during biomechanical tests. A series of points on the femur and tibia were digitized to create bone coordinate systems that were used to calculate the kinematic variables. Biomechanical testing involved applying a 5 Nm internal rotation moment to the tibia while the knee was in full extension and tested sequentially in the following three conditions: i) ACLintact; ii) Partial ACL injury (ACLam) -anteromedial bundle sectioned; iii) Full ACL injury (ACLfull). The specimens were then randomized to either have the ALL sectioned first (ALLsec) followed by the LMPRsec or vice versa. Internal rotation and anterior translation of the tibia with respect to the femur were calculated. A mixed two-way (serial sectioning by ALL section order) repeated measures ANOVA (α = 0.05). Results: Compared to the ACLintact condition, internal rotation was found to be 1.78° (p=0.06), 3.74° (p=0.001), and 3.84° (p=0.001) greater following ACLfull, LMPRsec and ALLsec

  3. Effects of Initial Graft Tension on the Tibiofemoral Compressive Forces and Joint Position Following ACL Reconstruction

    PubMed Central

    Brady, Mark F.; Bradley, Michael P.; Fleming, Braden C.; Fadale, Paul D.; Hulstyn, Michael J.; Banerjee, Rahul

    2007-01-01

    Background The initial tension applied to an ACL graft at the time of fixation modulates knee motion and the tibiofemoral compressive loads. Purpose To establish the relationships between initial graft tension, tibiofemoral compressive force, and the neutral tibiofemoral position in the cadaver knee. Study Design Controlled Laboratory Study. Methods The tibiofemoral compressive forces and joint positions were determined in the ACL-intact knee at 0°, 20° and 90° knee flexion. The ACL was excised and reconstructed with a patellar tendon graft using graft tensions of 1, 15, 30, 60 and 90 N applied at 0°, 20° and 90° knee flexion. The compressive forces and neutral positions were compared between initial tension conditions and the ACL-intact knee. Results Increasing initial graft tension increased the tibiofemoral compressive forces. The forces in the medial compartment were 1.8 times those in the lateral compartment. The compressive forces were dependent on the knee angle at which the tension was applied. The greatest compressive forces occurred when the graft was tensioned with the knee in extension. An increase in initial graft tension caused the tibia to rotate externally compared to the ACL-intact knee. Increases in initial graft tension also caused a significant posterior translation of the tibia relative to the femur. Conclusions Different initial graft tension protocols produced predictable changes in the tibiofemoral compressive forces and joint positions. Clinical Relevance The tibiofemoral compressive force and neutral joint position were best replicated with a low graft tension (1–15 N) when using a patellar tendon graft. PMID:17218659

  4. Decreased calcitonin gene-related peptide expression in the dorsal root ganglia of TNF-deficient mice in a monoiodoacetate-induced knee osteoarthritis model

    PubMed Central

    Taniguchi, Aya; Ishikawa, Tetsuhiro; Miyagi, Masayuki; Kamoda, Hiroto; Sakuma, Yoshihiro; Oikawa, Yasuhiro; Kubota, Go; Inage, Kazuhide; Sainoh, Takeshi; Nakamura, Junichi; Aoki, Yasuchika; Toyone, Tomoaki; Inoue, Gen; Suzuki, Miyako; Yamauchi, Kazuyo; Suzuki, Takane; Takahashi, Kazuhisa; Ohtori, Seiji; Orita, Sumihisa

    2015-01-01

    Background: The detailed mechanisms of knee osteoarthritis (OA) pain have not been clarified, but involvement of inflammatory cytokines such as tumor necrosis factor-alpha (TNF) has been suggested. The present study aimed to investigate the more detailed neurological involvement of TNF in joint pain using a TNF-knockout mouse OA model. Methods: The right knees of twelve-week-old C57BL/6J wild and TNF-deficient knockout (TNF-ko) mice (n=15, each group) were given a single intra-articular injection of 10 µg monoiodoacetate in 10 mL sterile saline. The left knees were only punctured as the control. Evaluations were performed immediately after the injection (baseline) and at 7, 14, and 28 days after the injection with a subsequent intra-articular injection of neurotracer into both knees. The animals were evaluated for immunofluorescence of the lumbar dorsal root ganglia (DRG) innervating the knee joints. The injected knees were observed macroscopically and mouse pain-related behaviors were scored. Results: Macroscopic observation showed similar knee OA development in both wild and TNF-ko mice. Calcitonin gene-related peptide (CGRP, a neuropeptide identified as a inflammatory pain-related biomarker) was significantly increased in DRG neurons innervating OA-induced knee joints with significantly less CGRP expression in TNF-ko animals. Pain-related behavior scoring showed a significant increase in pain in OA-induced joints, but there was no significant difference in pain observed between the wild and TNF-ko mice. Conclusions: The result of the present study indicates the possible association of TNF-alpha in OA pain but not OA development. PMID:26722492

  5. Electrospinning polymer blends for biomimetic scaffolds for ACL tissue engineering

    NASA Astrophysics Data System (ADS)

    Garcia, Vanessa Lizeth

    The anterior cruciate ligament (ACL) rupture is one of the most common knee injuries. Current ACL reconstructive strategies consist of using an autograft or an allograft to replace the ligament. However, limitations have led researchers to create tissue engineered grafts, known as scaffolds, through electrospinning. Scaffolds made of natural and synthetic polymer blends have the potential to promote cell adhesion while having strong mechanical properties. However, enzymes found in the knee are known to degrade tissues and affect the healing of intra-articular injuries. Results suggest that the natural polymers used in this study modify the thermal properties and tensile strength of the synthetic polymers when blended. Scanning electron microscopy display bead-free and enzyme biodegradability of the fibers. Raman spectroscopy confirms the presence of the natural and synthetic polymers in the scaffolds while, amino acid analysis present the types of amino acids and their concentrations found in the natural polymers.

  6. Comparison of ACL strain estimated via a data-driven model with in vitro measurements.

    PubMed

    Weinhandl, Joshua T; Hoch, Matthew C; Bawab, Sebastian Y; Ringleb, Stacie I

    2016-11-01

    Computer modeling and simulation techniques have been increasingly used to investigate anterior cruciate ligament (ACL) loading during dynamic activities in an attempt to improve our understanding of injury mechanisms and development of injury prevention programs. However, the accuracy of many of these models remains unknown and thus the purpose of this study was to compare estimates of ACL strain from a previously developed three-dimensional, data-driven model with those obtained via in vitro measurements. ACL strain was measured as the knee was cycled from approximately 10° to 120° of flexion at 20 deg s(-1) with static loads of 100, 50, and 50 N applied to the quadriceps, biceps femoris and medial hamstrings (semimembranosus and semitendinosus) tendons, respectively. A two segment, five-degree-of-freedom musculoskeletal knee model was then scaled to match the cadaver's anthropometry and in silico ACL strains were then determined based on the knee joint kinematics and moments of force. Maximum and minimum ACL strains estimated in silico were within 0.2 and 0.42% of that measured in vitro, respectively. Additionally, the model estimated ACL strain with a bias (mean difference) of -0.03% and dynamic accuracy (rms error) of 0.36% across the flexion-extension cycle. These preliminary results suggest that the proposed model was capable of estimating ACL strains during a simple flexion-extension cycle. Future studies should validate the model under more dynamic conditions with variable muscle loading. This model could then be used to estimate ACL strains during dynamic sporting activities where ACL injuries are more common. PMID:27030937

  7. Knee Bracing After Anterior Cruciate Ligament Reconstruction.

    PubMed

    Rodríguez-Merchán, E Carlos

    2016-07-01

    Although some articles in the literature are in favor of the use of a postoperative brace after anterior cruciate ligament (ACL) reconstruction, this review found that several systematic reviews and other reports on the topic do not support the use of a postoperative brace after ACL reconstruction. There is no scientific evidence so far to support the routine use of a functional knee brace following a successful ACL reconstruction in the postoperative course. Most authors believe that bracing is not necessary. There is insufficient evidence to inform current practice. Good-quality randomized trials are required to remedy this situation. Future studies should better define the role of a brace following ACL surgery. A search of MEDLINE for articles published between January 1, 1995, and September 30, 2013, was performed. Key search terms used were ACL reconstruction and knee brace. Ninety-one articles were found, but only 28 focused on the subject of bracing after ACL reconstruction and were selected for this review. Several systematic reviews and randomized, controlled trials on the topic do not recommend the use of postoperative brace after ACL reconstruction. Postoperative bracing after ACL reconstruction does not seem to help with pain, function, rehabilitation, and stability. The literature does not support the use of a postoperative brace following ACL reconstruction. [Orthopedics. 2016; 39(4):e602-e609.]. PMID:27203412

  8. Increased Platelet Concentration does not Improve Functional Graft Healing in Bio-Enhanced ACL Reconstruction

    PubMed Central

    Fleming, Braden C.; Proffen, Benedikt L.; Vavken, Patrick; Shalvoy, Matthew R.; Machan, Jason T.; Murray, Martha M.

    2014-01-01

    Purpose The use of an extra-cellular matrix scaffold (ECM) combined with platelets to enhance healing of an ACL graft (“bio-enhanced ACL reconstruction”) has shown promise in animal models. However, the effects of platelet concentration on graft healing remains unknown. The objectives of this study were to determine if increasing the platelet concentration in the ECM scaffold would; 1) improve the graft biomechanical properties, and 2) decrease cartilage damage after surgery. Methods Fifty-five adolescent minipigs were randomized to 5 treatment groups; untreated ACL transection (n=10), conventional ACL reconstruction (n=15), and bio-enhanced ACL reconstruction using 1X (n=10), 3X (n=10) or 5X (n=10) platelet-rich plasma. The graft biomechanical properties, anteroposterior (AP) knee laxity, graft histology and macroscopic cartilage integrity were measured at 15 weeks. Results The mean linear stiffness of the bio-enhanced ACL reconstruction procedure using the 1X preparation was significantly greater than traditional reconstruction while the 3X and 5X preparations were not. The failure loads of all the ACL reconstructed groups were equivalent but significantly greater than untreated ACL transection. There were no significant differences in the ligament maturity index or AP laxity between reconstructed knees. Macroscopic cartilage damage was relatively minor, though significantly less when the ECM-platelet composite was used. Conclusions Only the 1X platelet concentration improved healing over traditional ACL reconstruction. Increasing the platelet concentration from 1X to 5X in the ECM scaffold did not further improve the graft mechanical properties. The use of an ECM-platelet composite decreased the amount of cartilage damage seen after ACL surgery. PMID:24633008

  9. Comparison of the Insall-Salvati ratio of the patella in patients with and without an ACL tear.

    PubMed

    Lin, Chien-Fu Jeff; Wu, Jiunn-Jer; Chen, Teng-Shung; Huang, Tung-Fu

    2005-01-01

    The object of this prospective study is to compare the Insall-Salvati ratio between the patients who have an anterior cruciate ligament (ACL) tear and receive arthroscopic-assistant ACL reconstruction and the patients who have no ACL tear but do have an internal disorder of the knee and receive arthroscopic surgery. We prospectively and consecutively collected into two groups a total of 217 patients who had sport injuries and received arthroscopic surgery. The study group included 115 patients who had an ACL tear and received arthroscopic-assistant ACL reconstruction with middle-third bone-patella tendon-bone graft. The control group included 102 patients with internal disorders of the knee joint, including meniscus tear, plicae, or other chondral lesion, but without an ACL tear. We measured the patellar Insall-Salvati ratio [12] on the pre-operative X-ray films for all patients. The Insall-Salvati ratio in the ACL-tear study group is significantly smaller than the control group of internal disorders of the knee (0.99+/-0.11 vs 1.05+/-0.12, p=0.001). There is no significant difference in age, gender, the side of the involved knee, duration of symptoms, patella length and patella tendon length between the two groups. In conclusion, our study shows that patella infra has an association with ACL tears, and patella infra may be a risk factor for ACL tears. In patients with an ACL tear who had patella baja, the middle-third patellar tendon may not be an ideal graft for reconstruction. PMID:15654645

  10. Meniscus treatment and age associated with narrower radiographic joint space width 2 – 3 years after ACL reconstruction: Data from the MOON onsite cohort

    PubMed Central

    Jones, Morgan H.; Spindler, Kurt P.; Fleming, Braden C.; Duryea, Jeffrey; Obuchowski, Nancy A.; Scaramuzza, Erica A.; Oksendahl, Heidi L.; Winalski, Carl S.; Duong, Carol L.; Huston, Laura J.; Parker, Richard D.; Kaeding, Christopher C.; Andrish, Jack T.; Flanigan, David C.; Dunn, Warren R.; Reinke, Emily K.

    2015-01-01

    Objective To identify risk factors for radiographic signs of post-traumatic OA 2–3 years after ACL reconstruction through multivariable analysis of minimum joint space width (mJSW) differences in a specially designed nested cohort. Methods A nested cohort within the Multicenter Orthopaedic Outcomes Network cohort included 262 patients (148 females, average age 20) injured in sport who underwent ACL reconstruction in a previously uninjured knee, were 35 or younger, and did not have ACL revision or contralateral knee surgery. mJSW on semi-flexed radiographs was measured in the medial compartment using a validated computerized method. A multivariable generalized linear model was constructed to assess mJSW difference between the ACL reconstructed and contralateral control knees while adjusting for potential confounding factors. Results Unexpectedly, we found the mean mJSW was 0.35 mm wider in ACL reconstructed than in control knees (5.06 mm (95% CI 4.96 – 5.15 mm) versus 4.71 mm (95% CI 4.62 – 4.80 mm), p<0.001). However, ACL reconstructed knees with meniscectomy had narrower mJSW compared to contralateral normal knees by 0.64 mm (95% C.I. 0.38 – 0.90 mm) (p<0.001). Age (p<0.001) and meniscus repair (p=0.001) were also significantly associated with mJSW difference. Conclusion Semi-flexed radiographs can detect differences in mJSW between ACL reconstructed and contralateral normal knees 2–3 years following ACL reconstruction, and the unexpected wider mJSW in ACL reconstructed knees may represent the earliest manifestation of post-traumatic osteoarthritis and warrants further study. PMID:25559582

  11. Risk Factors and Predictors Of Subsequent ACL Injury After ACL Reconstruction: Prospective Analysis Of 2801 Primary ACL Reconstructions

    PubMed Central

    Kaeding, Christopher C.; Pedroza, Angela; Reinke, Emily; Huston, Laura J.; Spindler, Kurt P.

    2014-01-01

    Objectives: Retear of an ACL after an ACL reconstruction (ACLR) is devastating for all involved. Understanding risk factors and predictors of subsequent ACL tear after an ACLR is vital for patient education of subsequent risk of injury and if a predictor is modifiable, to make adjustments to minimize the risk of repeat ACL tear. The objectives of this study were 1) to identify the risk factors and predictors for ispilateral and contralateral ACL tears after primary ACLR and 2) to compare retear risk between the 2002/03 and 2007/08 cohorts. This is the largest and most comprehensive prospective analysis of this kind in the literature. Methods: Data from the 2002-2008 MOON database was used to identify risk factors for ACL retear. Subjects who had a primary ACLR with no history of contralateral knee surgery and had 2 year follow-up data were included. Subjects who had multiligament surgery were excluded. Graft type (auto-BTB, auto-hamstring, allograft), age, Marx score at time of index surgery, sport played post ACLR, sex, smoking status, lateral meniscus tear at the time of ACLR, medial meniscus tear at the time of ACLR, BMI, and MOON site were evaluated to determine their contribution to both ipsilateral retear and contralateral ACL tear. The analysis was repeated using the 2002/3 and 2007/8 cohort and included age, graft, sex, and Marx. An ANOVA with post-hoc analysis was performed to detect significant differences in age and Marx score by graft type over time. Results: A total of 2801 subjects met all inclusion/exclusion criteria. There were 165/2801 (5.89%) ipsilateral and 177/2801 (6.32%) contralateral ACL tears identified in the cohort at the two year follow-up. The odds of ipsilateral retear are 1.68 times greater for hamstring autograft (p=0.04) and 4.67 times greater for an allograft (p<0.001) compared to auto-BTB. The odds of ipsilateral retear decrease by 8% for every yearly increase in age (p < 0.001) and increases by 6% for every increased point on the

  12. ACL reconstruction by patellar tendon. A comparison of length by magnetic resonance imaging.

    PubMed

    Högerle, S; Letsch, R; Sievers, K W

    1998-01-01

    In 50 knees the length of the anterior cruciate ligament (ACL), the patellar tendon, and the distance between the tibial tuberosity and the femoral origin of the ACL were evaluated by means of three-dimensional magnetic resonance imaging (MRI), which permits subsequent reconstruction of any sectional view. The measurements showed that the patellar tendon was always markedly longer than the ACL (mean 14.4 mm), but always shorter than the distance between the tibial tuberosity and the femoral insertion of the ACL (mean 19.2 mm). The mean lengths of the ACL and the patellar tendon were 38.2 mm and 52.6 mm, respectively. The mean distance between the femoral ACL origin and the tibial insertion of the patellar tendon was 71.8 mm. These results demonstrate that a distally based patellar tendon autograft alone (with the patellar bone block but without extension into the periosteum of the patella or the quadriceps tendon) cannot be placed anatomically correctly to the isometric femoral insertion of the ACL. When the patellar tendon is used for ACL reconstruction, it must be implanted as a free autograft. Nevertheless, considerable variations of length must be taken into account. PMID:9457339

  13. Anatomical versus Non-Anatomical Single Bundle Anterior Cruciate Ligament Reconstruction: A Cadaveric Study of Comparison of Knee Stability

    PubMed Central

    Lim, Hong-Chul; Yoon, Yong-Cheol; Wang, Joon-Ho

    2012-01-01

    Background The purpose of this study was to compare the initial stability of anatomical and non-anatomical single bundle anterior cruciate ligament (ACL) reconstruction and to determine which would better restore intact knee kinematics. Our hypothesis was that the initial stability of anatomical single bundle ACL reconstruction would be superior to that of non-anatomical single bundle ACL reconstruction. Methods Anterior tibial translation (ATT) and internal rotation of the tibia were measured with a computer navigation system in seven pairs of fresh-frozen cadaveric knees under two testing conditions (manual maximum anterior force, and a manual maximum anterior force combined with an internal rotational force). Tests were performed at 0, 30, 60, and 90 degrees of flexion with the ACL intact, the ACL transected, and after reconstruction of one side of a pair with either anatomical or non-anatomical single bundle ACL reconstruction. Results Under manual maximal anterior force, both reconstruction techniques showed no significant difference of ATT when compared to ACL intact knee state at 30° of knee flexion (p > 0.05). Under the combined anterior and internal rotatory force, non-anatomical single-bundle ACL reconstruction showed significant difference of ATT compared to those in ACL intact group (p < 0.05). In contrast, central anatomical single bundle ACL reconstruction showed no significant difference of ATT compared to those in ACL intact group (p > 0.05). Internal rotation of the tibia showed no significant difference in the ACL intact, the ACL transected, non-anatomical reconstructed and anatomical reconstructed knees. Conclusions Anatomical single bundle ACL reconstruction restored the initial stability closer to the native ACL under combined anterior and internal rotational forces when compared to non-anatomical ACL single bundle reconstruction. PMID:23205233

  14. A modeling study of partial ACL injury: simulated KT-2000 arthrometer tests.

    PubMed

    Liu, Wen; Maitland, Murray E; Bell, G Douglas

    2002-06-01

    A partial ACL injury may involve different levels of fiber disruption, orfibers may sustain microscopic changes in their structure without gross disruption, resulting in a change in ligament function. The effect of partial ACL tears on the mechanical and functional stability of the knee has not been well documented, in part because of diagnostic difficulties. A computer model of the knee in the sagittal plane was used in this study to simulate tests using the KT-2000 Knee Arthrometer, which quantifies Lachman's test for ACL injury. A variety of partial ACL anterior and posterior bundle injuries were simulated. Anterior and posterior bundle injuries were subdivided into four different simulated injury levels: mild (one-half tear of the bundle), moderate (complete tear of the bundle), severe (complete tear of the bundle and tear of one-half of the other bundle), and more severe (severe injury plus an additional elongation of the other bundle represented by 5% increases of its initial strain). Force-displacement results obtained from simulated KT-2000 knee arthrometer tests depended on the level of injury. Mild and moderate injuries produced only small change in the anterior tibial translation--at different force levels. Severe injury produced increased anterior tibial translation depending on which bundle was completely ruptured. The compliance index defined as the ratio of the displacement and the force within 68 N and 90 N anterior drawer forces, the stiffness, and the rate of change of stiffness of the anterior force-displacement were found to be better at predicting partial ACL ruptures than simple differences in anterior tibial translation. It was possible in the model results to discriminate knees with various levels of partial ACL injuries using the first and second derivatives of the force-displacement curve. PMID:12071264

  15. Muscle Preactivity of Anterior Cruciate Ligament-Deficient and -Reconstructed Females During Functional Activities

    PubMed Central

    DeMont, Richard G.; Lephart, Scott M.; Giraldo, Jorge L.; Swanik, C. Buz; Fu, Freddie H.

    1999-01-01

    Objective: Underlying the ability of the hamstrings to decrease tibial anterior shear is the time of firing in comparison with the quadriceps. This timing may be aided by neural programming during a planned or expected activity. It is theorized that individuals who have better programming ability will suffer fewer anterior cruciate ligament (ACL) injuries due to joint protection through muscular stabilization. A component of this dynamic restraint is the development of muscular tension before the knee is loaded. The objective of our study was to compare the muscular activity before footstrike in ACL-deficient (ACL-D), ACL-reconstructed (ACL-R), and control (C) females during functional activities. Design and Setting: Active females were divided into groups based on their ACL status. The study was conducted in a neuromuscular research laboratory. Subjects: Twenty-four female subjects (ACL-D = 6, ACL-R = 12, C = 6). Measurements: Integrated electromyographic (IEMG) activity from the thigh (vastus medialis obliquus [VMO], vastus lateralis [VL], medial hamstring, and lateral hamstring) and leg (medial gastrocnemius and lateral gastrocnemius [LG]) and footswitch signals were recorded during downhill walking (15° at 0.92 m/s), running (2.08 m/s), hopping, and landing from a step (20.3 cm). IEMG activity was normalized to the mean amplitude of the sample and analyzed for area and mean amplitude for 150 milliseconds before heelstrike. Side-to-side differences were determined by t tests, and separate one-way analyses of variance (ANOVA) were used to detect differences among the 3 groups for each muscle of each activity. Results: IEMG area side-to-side differences for the ACL-D group appeared in the LG (involved [I] = 36.4 ± 19.7, uninvolved [U] = 60.1 ± 23.6) during landing, in the VMO (I = 11.4 ± 3.8, U = 7.2 ± 3.1) and VL (I = 13.3 ± 2.7, U = 8.9 ± 1.9) during running, and in the VMO (I = 9.2 ± 4.2, U = 19.5 ± 7.3) during downhill walking. IEMG mean amplitude

  16. Descriptive Epidemiology of the Multicenter ACL Revision Study (MARS) Cohort

    PubMed Central

    2013-01-01

    Background Revision anterior cruciate ligament (ACL) reconstruction has worse outcomes than primary reconstructions. Predictors for these worse outcomes are not known. The Multicenter ACL Revision Study (MARS) Group was developed to perform a multisurgeon, multicenter prospective longitudinal study to obtain sufficient subjects to allow multivariable analysis to determine predictors of clinical outcome. Purpose To describe the formation of MARS and provide descriptive analysis of patient demographics and clinical features for the initial 460 enrolled patients to date in this prospective cohort. Study Design Cross-sectional study; Level of evidence, 2. Methods After training and institutional review board approval, surgeons began enrolling patients undergoing revision ACL reconstruction, recording patient demographics, previous ACL reconstruction methods, intra-articular injuries, and current revision techniques. Enrolled subjects completed a questionnaire consisting of validated patient-based outcome measures. Results As of April 1, 2009, 87 surgeons have enrolled a total of 460 patients (57% men; median age, 26 years). For 89%, the reconstruction was the first revision. Mode of failure as deemed by the revising surgeon was traumatic (32%), technical (24%), biologic (7%), combination (37%), infection (<1%), and no response (<1%). Previous graft present at the time of injury was 70% autograft, 27% allograft, 2% combination, and 1% unknown. Sixty-two percent were more than 2 years removed from their last reconstruction. Graft choice for revision ACL reconstruction was 45% autograft, 54% allograft, and more than 1% both allograft and autograft. Meniscus and/or chondral damage was found in 90% of patients. Conclusion The MARS Group has been able to quickly accumulate the largest revision ACL reconstruction cohort reported to date. Traumatic reinjury is deemed by surgeons to be the most common single mode of failure, but a combination of factors represents the most

  17. Strain distribution in the ligament using photoelasticity. A direct application to the human ACL.

    PubMed

    Yamamoto, K; Hirokawa, S; Kawada, T

    1998-04-01

    Large and highly variable deformations of the anterior cruciate ligament (ACL) in the human knee cannot be adequately quantified by one-dimensional and/or localized measurements. In order to measure strains in the entire area of the ACL, we employed the photoelastic coating method to analyze stress on the basis of the strains. A specific kind of polyurethane possessing optically high fringe-sensitivity was found to be most suitable for the measurement purposes. Although the photoelastic method has been successfully applied in various fields for stress analyses, its use in studying large deformations of biological tissues has not been reported. Therefore, before proceeding with our main study, we first examined the effects of polyurethane film on the mechanical properties of the ligament. We found that the film had a negligible effect on the tissues' properties, and closely reflected the strain behavior of the tissues. We then applied the method to measure strains on an actual ACL during free flexion-extension of the knee. A specially designed apparatus was used to allow a natural motion of the knee. A portion of the femoral bone was removed to expose the ACL to view. Measurement and analysis gave continuous information about strain distribution, including the variations of strain along the principal strain directions in the ACL. PMID:9690485

  18. The effect of accelerated, brace free, rehabilitation on bone tunnel enlargement after ACL reconstruction using hamstring tendons: a CT study.

    PubMed

    Vadalà, Antonio; Iorio, Raffaele; De Carli, Angelo; Argento, Giuseppe; Di Sanzo, Vincenzo; Conteduca, Fabio; Ferretti, Andrea

    2007-04-01

    The mechanism of bone tunnel enlargement following anterior cruciate ligament (ACL) reconstruction is not yet clearly understood. Many authors hypothesized that aggressive rehabilitation protocols may be a potential factor for bone tunnel enlargement, especially in reconstructions performed with hamstrings autograft. The purpose of this study was to evaluate the effect of a brace free rehabilitation on the tunnel enlargement after ACL reconstruction using doubled semitendinosus and gracilis tendons (DGST): our hypothesis was that early post-operative knee motion increase the diameters of the tibial and femoral bone tunnels. Forty-five consecutive patients undergoing ACL reconstruction for chronic ACL deficiency were selected. All patients were operated by the same surgeon using autologous DGST and the same fixation devices. Patients with associated ligaments injuries and or severe chondral damage were excluded. The patients were randomly assigned to enter the control group (group A, standard post-operative rehabilitation) and the study group (group B, brace free accelerated rehabilitation). A CT scan was used to exactly determine the diameters of both femoral and tibial tunnels at various levels of lateral femoral condyle and proximal tibia, using a previously described method [17]. Measurements were done by an independent radiologist in a blinded fashion the day after the operation and at a mean follow-up of 10 months (range 9-11). Statistical analysis was performed using paired t-test. The mean femoral tunnel diameter increased significantly from 9.04 +/- 0.05 (post-operative) to 9.30 +/- 0.8 mm (follow-up) in group A and from 9.04 +/- 0.03 to 9.94 +/- 1.12 mm in group B. The mean tibial tunnel diameter increased significantly from 9.03 +/- 0.04 to 10.01 +/- 0.80 mm in group A and from 9.04 +/- 0.03 to 10.60 +/- 0.78 mm in group B. The increase in femoral and tunnel diameters observed in the study group was significantly higher than that observed in the control

  19. Reduced Anterior Cruciate Ligament Vascularization Is Associated With Chondral Knee Lesions.

    PubMed

    Hetsroni, Iftach; Manor, Amir; Finsterbush, Alex; Lowe, Joseph; Mann, Gideon; Palmanovich, Ezequiel

    2016-07-01

    This study tested the association between periligamentous vascularization of the anterior cruciate ligament (ACL) and the presence of chondral knee lesions via retrospective analysis of prospectively collected data from 702 consecutive knee arthroscopic procedures. In each case, the ACL periligamentous envelope was documented as follows: (1) vascular, where the ACL was covered with blood vessels along its entire length; (2) centrally avascular, where the central third of the ACL was not covered but peripheral vascularized coverage was present; and (3) avascular, where there was no blood vessel coverage of the ACL. Inclusion criteria for the study were as follows: (1) age older than 18 years and (2) normal knee ligament laxity. Univariate analysis and multiple logistic regression were used to test the association between chondral lesions and each of the variables: sex, age, meniscus tear, decreased ACL vascularity, and concomitant chondral lesion in another knee compartment. The cohort included 516 knees. In the univariate analysis, all variables were associated with a chondral lesion, but only older age and decreased ACL vascularity were associated with chondral lesions in each knee compartment. In the regression model, only decreased ACL vascularity was associated with chondral lesions in each knee compartment. For avascular knees, the odds ratio was 2.84 for medial femoral condyle lesions (95% confidence interval, 1.73-4.68; P=.000), 2.44 for lateral femoral condyle lesions (95% confidence interval, 1.19-5.03; P=.015), and 2.48 for patellofemoral lesions (95% confidence interval, 1.55-3.97; P=.000). The findings showed that decreased ACL periligamentous vascularization is associated with chondral lesions of the femoral condyles in knees with preserved ACL laxity. [Orthopedics. 2016; 39(4):e737-e743.]. PMID:27111071

  20. Anterior Cruciate Ligament (ACL) Injuries

    MedlinePlus

    ... get ACL injuries usually play contact sports (like football) or sports that feature swift, abrupt movements such ... the things you love — like running or playing football, field hockey, or softball — can be frustrating. Recovering ...

  1. Influence of thermofixation on artificial ACL ligament dimensional and mechanical properties

    NASA Astrophysics Data System (ADS)

    Ben Abdessalem, S.; Jedda, H.; Skhiri, S.; Karray, S.; Dahmen, J.; Boughamoura, H.

    2005-11-01

    The anterior cruciate ligament (ACL) is the major articular ligamentous structure of the knee, it functions as a joint stabilizer. When ruptured, the natural ACL ligament can be replaced by a textile synthetic ligament such as a braid, knitted cord, or woven cord. Theses structures are composed of biocompatible materials such as polyester or Gore-Tex filaments. The success of an ACL replacement is widely linked to its mechanical and dimensional properties such as tensile strength, dimensional stability and resistance to abrasion. We introduced an additional treatment in the manufacturing of textile ACL ligaments based on the thermofixation of the textile structure by using textile industry stabilization techniques. Boiling water, saturated vapor and dry heat have been tested to stabilize a braided ligament made of Dacron polyester. The application of these three techniques led to shrinkage and an increase of breaking strength of the textile structure.

  2. Quality of life assessment scores after ACL reconstruction. 223 patients from the Unisports clinic

    PubMed Central

    Rosenfeldt, MP; Stanley, J; Walsh, SJ; Twaddle, BC; Tietjens, BR

    2016-01-01

    Objective: Determination of the effectiveness of ACL reconstruction requires outcome measures. Traditionally these have been based on a clinical assessment by the surgeon. The most important outcomes to measure are those that are important to the patient themselves. Methods: Over a 5-year period all eligible patients completed a validated ACL-QOL outcome measure. This proved to be a very difficult group to follow with only 22% of eligible patients completing all data forms. Results: ACL provided improved function across of categories on 1 year ACL-QOL scores. There remained a significant deficit to a “normal” knee score. Conclusion: Highlighting the importance of prospective data collection, patients had worse retrospective scores at 1 year than they had prospectively.

  3. An Integrated Approach to Change the Outcome Part II: Targeted Neuromuscular Training Techniques to Reduce Identified ACL Injury Risk Factors

    PubMed Central

    Myer, Gregory D.; Ford, Kevin R.; Brent, Jensen L.; Hewett, Timothy E.

    2014-01-01

    Prior reports indicate that female athletes who demonstrate high knee abduction moments (KAMs) during landing are more responsive to neuromuscular training designed to reduce KAM. Identification of female athletes who demonstrate high KAM, which accurately identifies those at risk for noncontact anterior cruciate ligament (ACL) injury, may be ideal for targeted neuromuscular training. Specific neuromuscular training targeted to the underlying biomechanical components that increase KAM may provide the most efficient and effective training strategy to reduce noncontact ACL injury risk. The purpose of the current commentary is to provide an integrative approach to identify and target mechanistic underpinnings to increased ACL injury in female athletes. Specific neuromuscular training techniques will be presented that address individual algorithm components related to high knee load landing patterns. If these integrated techniques are employed on a widespread basis, prevention strategies for noncontact ACL injury among young female athletes may prove both more effective and efficient. PMID:22580980

  4. The Effects of Balance Training on Static and Dynamic Postural Stability Indices After Acute ACL Reconstruction

    PubMed Central

    Akbari, Asghar; Ghiasi, Fateme; Mir, Mohsen; Hosseinifar, Mohammad

    2016-01-01

    Background: Proprioception and postural stability play an important role in knee movements. However, there are controversies about the overall recovery time of proprioception following knee surgery and onset of balance and neuromuscular training after ACL reconstruction. Therefore, it is necessary to evaluate the effect of balance training in early stage of knee rehabilitation after anterior cruciate ligament (ACL) reconstruction. The purpose of this study was to evaluate the effect of balance exercises on postural stability indices in subjects with anterior cruciate ligament (ACL) reconstruction. Methods: The study was a controlled randomized trial study. Twenty four patients who had ACL reconstructed (balance training group) and twenty four healthy adults without any knee injury (control group) were recruited in the study. The balance exercises group performed balance exercises for 2 weeks. Before and after the interventions, overall, anteroposterior, and mediolateral stability indices were measured with a Biodex Balance System in bilateral and unilateral stance positions with the eyes open and closed. T-tests were used for statistical analysis (p<0.05). Results: Results showed that amount of static stability indices did not change after training and there were not significant differences in static stability indices before and after balance training (p>0.05). Although amount of dynamic stability indices decreased, there were not significant differences in dynamic stability indices before and after balance training (p>0.05). Amount of dynamic stability indices were decreased in balance training group, however, there were not significant differences between groups (p>0.05). Conclusion: These results support that balance exercise could partially improved dynamic stability indices in early stage of ACL reconstruction rehabilitation. The results of this study suggest that balance exercises should be part of the rehabilitation program following ACL reconstruction. PMID

  5. Relationship between Mucoid Degeneration of the Anterior Cruciate Ligament and Posterior Tibial Slope in Patients with Total Knee Arthroplasty

    PubMed Central

    Youm, Yoon-Seok; Cho, Hye-Yong; Jung, Seung-Hyun

    2016-01-01

    Purpose The purpose was to analyze the relationship between posterior tibial slope (PTS) and mucoid degeneration of the anterior cruciate ligament (ACL) in patients with total knee arthroplasty. Materials and Methods Four hundred and twenty-four patients (24 males and 400 females; 636 knees) who received total knee arthroplasty for osteoarthritis were included. Their mean age was 68.9 years (range, 48 to 88 years). The patients were classified into three groups according to the status of ACL; normal ACL group (group I), mucoid degeneration of ACL group (group II) and ruptured or absent ACL group (group III). Plain lateral radiographs were used to measure the PTS and the values were compared among groups. Results There were no significant differences with regard to gender, age and left-to-right side ratio among groups (p>0.05). The mean PTS was 9.9° (range, 0.6° to 20.1°) in group I (161 knees), 10.8° (range, 0.2° to 21.8°) in group II (342 knees) and 12.3° (range, 2° to 22.2°) in group III (133 knees), which showed significant differences (p<0.001). Conclusions The patients with mucoid degeneration of the ACL and those with ruptured or absent ACL had greater PTS than those with normal ACL. These findings suggest that an increased PTS may be one of the causative factors for mucoid degeneration of the ACL. PMID:26955611

  6. A complication following ACL reconstruction using bioabsorbable cross-pins.

    PubMed

    Vecchini, Eugenio; Micheloni, Gian Mario; Corbo, Valentina Rita; Perusi, Francesco; Dib, Giovanni; Magnan, Bruno

    2016-01-01

    This is a case of a proximal pin migration after ACL reconstruction in medial soft tissue with pain, inflammatory reaction and functional reduction. 33-year-old male presented at our clinic with a complete ACL rupture. Reconstruction with autogenous gracilis and semitendinosus hamstring tendons was performed and graft fixed in the femoral canal with two PLLA bioabsorbable pins (RIGIDFIX® Cross Pin System). Two months postoperatively the patient presented swelling and pain on the medial side of the knee, full range of motion and negative results at the Lachman and Pivot shift tests. MRI examination showed the superior femoral tunnel crossing both the lateral and medial cortex lodging the pin in the knee's medial soft tissue corresponding to the swelling area reported by the patient. The tendon graft was properly positioned. After surgical removal of the pin through a small skin incision, the pain and swelling promptly subsided allowing the patient return to normal activities in few weeks without any pain. In our opinion the painful swelling of the knee was due to a displacement of the pin that had been accidentally lodged in the soft tissues instead of the bone causing a foreign-body reaction resulting in granuloma formation with local inflammation. This dislodgement could have been due to an inappropriately long femoral tunnel. PMID:27104331

  7. Anterior cruciate ligament (ACL) injury

    MedlinePlus

    ... side of your knee, such as during a football tackle Overextend your knee joint Quickly stop moving ... running, landing from a jump, or turning Basketball, football, soccer, and skiing are common sports linked to ...

  8. The female ACL: why is it more prone to injury?

    PubMed

    Ireland, Mary Lloyd

    2002-10-01

    Multiple factors are responsible for ACL tears. The key factor in the gender discrepancy appears to be dynamic, not static, and proximal, not distal. The factors involved in evaluating the female ACL are multiple. However, it is the dynamic movement patterns ot hip and knee position with increased flexion and a coordinated proximal muscle firing pattern to keep the body in a safe landing position that are the most critical factors. An ACL injury at an early age is a life-changing event. We can very successfully reconstruct and rehabilitate an ACL, but we cannot stop there. We must now go into the prevention arena. In the United States there is tremendous variation in the exposure and acquisition of skills of physical activities in our youth. Today, children are often playing inside, using computers and watching television-missing out on the opportunity to learn safe movement patterns. Therefore, physical movement classes should occur very early in life, teaching children to land safely and in control, similar to the cry of "get down, stay down" routinely heard during youth soccer. Similarly, specific strength training programs can address landing as well as foot movements during cutting in basketball. Coaches should issue stern warnings when athletes demonstrate a high-risk movement patterns such as one-leg landings, out-of-control baseline landings, or straight-leg landings. The warnings may serve to keep the athlete from "touching the hot stove again" for fear of getting burned. No athlete feels she will be the one to get injured. Therefore, prospective analysis is likely to be received more warmly by the athletes if the program is presented with an emphasis on performance improvement rather than injury prevention. With increased participation in these programs, multiple-center analysis will have the power necessary to determine which factors significantly predispose athletes to ACL injury. The future for injury prevention is bright. We must rise to the challenge

  9. Predictors of Lateral Compartment Joint Space Difference at a Minimum of Two Years after ACL Reconstruction

    PubMed Central

    Jones, Morgan H.; Reinke, Emily; Duryea, Jeffrey; Fleming, Braden C.; Obuchowski, Nancy; Winalski, Carl S.; Spindler, Kurt P.

    2016-01-01

    Objectives: ACL reconstruction effectively restores knee stability and allows a return to athletic activities after ACL injury, but patients are still at higher risk of developing post-traumatic OA. Patient reported outcomes from the Multicenter Orthopaedic Outcomes Network (MOON) prospective longitudinal cohort of over 1500 patients undergoing ACL reconstruction showed no increase in OA symptoms (KOOS subscale) at 2 or 6 years after surgery. Therefore, identification of structural changes of OA that may precede the onset of symptoms is of critical importance for determining risk factors for the initiation and progression of post-traumatic OA in addition to measuring the effectiveness of potential disease-modifying treatments. One structural measure of OA is radiographic joint space width (JSW). We previously demonstrated that meniscus treatment and age predict narrower medial compartment JSW. Methods: 335 patients from the MOON cohort (154 males, 181 females, median age 18 years at the time of surgery) were recruited at a minimum of 2 years following surgery for on-site evaluations including bilateral metatarsophalangeal joint (MTP) radiographs to assess JSW. To minimize bias related to pre-existing knee injury or OA, subjects were 35 years or younger, were injured playing a sport, had primary ACL reconstruction without prior meniscus or articular cartilage surgery, did not undergo subsequent ACL revision, and had a surgically normal contralateral knee. Radiographic JSW was measured in the lateral compartment of both knees using a validated semiautomated method. The association of age, sex, BMI, meniscus treatment, and articular cartilage treatment with lateral compartment JSW differences (JSD) between the reconstructed and normal knees was examined using multivariable generalized linear models. The Holm-Bonferroni method was used to account for multiple comparisons. Results: The mean lateral compartment JSW was 7.73 mm and (95% CI 7.61-7.85 mm) for ACL

  10. Fluoroscopic Analysis of Tibial Translation in Anterior Cruciate Ligament Injured Knees With and Without Bracing During Forward Lunge

    PubMed Central

    Jalali, Maryam; Farahmand, Farzam; Mousavi, Seyed Mohammad Ebrahim; Golestanha, Seyed Ali; Rezaeian, Tahmineh; Shirvani Broujeni, Shahram; Rahgozar, Mehdi; Esfandiarpour, Fateme

    2015-01-01

    Background: Despite several studies with different methods, the effect of functional knee braces on knee joint kinematics is not clear. Direct visualization of joint components through medical imaging modalities may provide the clinicians with more useful information. Objectives: In this study, for the first time in the literature, video fluoroscopy was used to investigate the effect of knee bracing on the sagittal plane kinematics of anterior cruciate ligament (ACL) injured patients. Patients and Methods: For twelve male unilateral ACL deficient subjects, the anterior tibial translation was measured during lunge exercise in non-braced and braced conditions. Fluoroscopic images were acquired from the subjects using a digital fluoroscopy system with a rate of 10 fps. The image of each frame was scaled using a calibration coin and analyzed in AutoCAD environment. The angle between the two lines, tangent to the posterior cortexes of the femoral and tibial shafts was measured as the flexion angle. For the fluoroscopic images associated with 0°, 15°, 30°, 45° and 60° knee flexion angles, the relative anterior-posterior configuration of the tibiofemoral joint was assessed by measuring the position of landmarks on the tibia and femur. Results: Results indicated that the overall anterior translations of the tibia during the eccentric (down) and concentric (up) phases of lunge exercise were 10.4 ± 1.7 mm and 9.0 ± 2.2 mm for non-braced, and 10.1 ± 3.4 mm and 7.4 ± 2.5 mm, for braced conditions, respectively. The difference of the tibial anterior-posterior translation behaviors of the braced and non-braced knees was not statistically significant. Conclusion: Fluoroscopic imaging provides an effective tool to measure the dynamic behavior of the knee joint in the sagittal plane and within the limitations of this study, the pure mechanical stabilizing effect of functional knee bracing is not sufficient to control the anterior tibial translation of the ACL deficient

  11. Recovery of Psychological Readiness May Differ Between Genders Following ACL Reconstruction in Adolescent Athletes

    PubMed Central

    Milewski, Matthew David; Kostyun, Regina; Iannicelli, Julie P.; Kostyun, Kyle J.; Solomito, Matthew; Nissen, Carl W.

    2016-01-01

    Objectives: Injury to the anterior cruciate ligament (ACL) is a traumatic and emotional event for adolescent athletes. Preparation to return to play (RTP) and the potential risk of re-injury are often equally as emotional as the injury, and have been identified as possible limiting factors to a successful rehabilitation and RTP. In order to create a comprehensive rehabilitation model, further understanding of psychological readiness following surgical intervention is needed. The purpose of this study was to determine if clinical outcomes of subjective knee function and psychological readiness differ between genders following ACL reconstruction surgery in adolescent athletes, and if higher knee function and physiological readiness was associated with an earlier to RTP. Methods: Athletes who underwent ACL reconstruction surgery and were successfully returned back to unrestricted sport were included in the analysis. At approximately six months post surgery, knee function was assessed using the validated International Knee Documentation Committee (IKDC) Subjective Form, and psychological readiness was assessed using the validated ACL-Return to Sport after Injury (ACL-RSI) scale. Formal clearance to resume unrestricted sport was obtained from clinic notes. A T-test was used to determine if demographics, IKDC and ACL-RSI scores between genders. A mixed effects random intercept regression model was used to determine the association of time to RTP with IKDC and ACL-RSI scores. Results: A total of 45 adolescent athletes (23 females) were included in this analysis. No significant differences were found between males and females for age (16.2±1.5 years, 16.3±2.2 years) and average time to RTP (7.3±2.0 months, 7.3±1.8 months). No significant differences in IKDC scores were found between males and females (88±10%, 87±10%). A trend was identified that males demonstrated higher ACL-RSI scores at six month post surgery than females (81±14%, 72±17%, p = 0.063). In females

  12. An Athlete's Nightmare: Tearing the ACL

    MedlinePlus

    ... Dr. Boden's ACL patients. There are many different theories as to why young women suffer a higher ... ACL injuries. Dr. Boden says there are other theories based on how estrogen affects the ligament, as ...

  13. Video analysis of trunk and knee motion during non-contact anterior cruciate ligament injury in female athletes: lateral trunk and knee abduction motion are combined components of the injury mechanism

    PubMed Central

    Hewett, T E; Torg, J S; Boden, B P

    2014-01-01

    Background The combined positioning of the trunk and knee in the coronal and sagittal planes during non-contact anterior cruciate ligament (ACL) injury has not been previously reported. Hypothesis During ACL injury female athletes demonstrate greater lateral trunk and knee abduction angles than ACL-injured male athletes and uninjured female athletes. Design Cross-section control-cohort design. Methods Analyses of still captures from 23 coronal (10 female and 7 male ACL-injured players and 6 female controls) or 28 sagittal plane videos performing similar landing and cutting tasks. Significance was set at p ≤ 0.05. Results Lateral trunk and knee abduction angles were higher in female compared to male athletes during ACL injury (p ≤ 0.05) and trended toward being greater than female controls (p = 0.16, 0.13, respectively). Female ACL-injured athletes showed less forward trunk lean than female controls (mean (SD) initial contact (IC): 1.6 (9.3)° vs 14.0 (7.3)°, p ≤ 0.01). Conclusion Female athletes landed with greater lateral trunk motion and knee abduction during ACL injury than did male athletes or control females during similar landing and cutting tasks. Clinical relevance Lateral trunk and knee abduction motion are important components of the ACL injury mechanism in female athletes as observed from video evidence of ACL injury. PMID:19372088

  14. Functional and muscle morphometric effects of ACL reconstruction. A prospective CT study with 1 year follow-up.

    PubMed

    Lindström, M; Strandberg, S; Wredmark, T; Felländer-Tsai, L; Henriksson, M

    2013-08-01

    Computed tomography (CT) was used to explore if changes in muscle cross-sectional area and quality after anterior cruciate ligament (ACL) injury and reconstruction would be related to knee function. Fourteen females and 23 males (16-54 years) underwent clinical tests, subjective questionnaires, and CT 1 week before and 1 year after ACL surgery with semitendinosus-gracilis (STG) graft and rehabilitation. Postoperatively, knee laxity was decreased and functional knee measures and subjective patient scores improved. The most obvious remaining deficit was the quadriceps atrophy, which was significantly larger if the right leg was injured. Right-leg injury also tended to cause larger compensatory hypertrophy of the combined knee flexor and tibial internal rotator muscles (preoperatively). The quadriceps atrophy was significantly correlated with the scores and functional tests, the latter also being related to the remaining size of the gracilis muscle. Biceps femoris hypertrophy and, in males only, semimembranosus hypertrophy was observed following the ACL reconstruction. The lack of semimembranosus hypertrophy in the women could, via tibial internal rotation torque deficit, contribute to the less favorable functional and subjective outcome recorded for the women. The results indicate that the quadriceps, the combined knee flexor/tibial internal rotator muscles, side of ACL injury, and sex are important to consider in rehabilitation after STG graft. PMID:22107159

  15. Return to Sport: When to Resume Full Activity After an ACL Surgery.

    PubMed

    2014-12-01

    Although surgery to fix a torn anterior cruciate ligament (ACL) is common, knowing when it is safe to return to activities and sports after ACL reconstruction is not always clear. As part of their rehabilitation, patients often fill out surveys, such as the International Knee Documentation Committee survey, that ask questions about how patients think they are recovering. It is not clear, though, how well these surveys truly predict an athlete's readiness to get back to activities and sports. A study published in the December 2014 issue of JOSPT provides new insight and evidence-based tools to help answer this question. PMID:25434851

  16. Strength Asymmetry and Landing Mechanics at Return to Sport after ACL Reconstruction

    PubMed Central

    Schmitt, Laura C.; Paterno, Mark V.; Ford, Kevin R.; Myer, Gregory D.; Hewett, Timothy E.

    2014-01-01

    Purpose Evidence-based quadriceps femoris muscle (QF) strength guidelines for return to sport following anterior cruciate ligament (ACL) reconstruction are lacking. This study investigated the impact of QF strength asymmetry on knee landing biomechanics at the time of return to sport following ACL reconstruction. Methods Seventy-seven individuals (17.4 years) at the time of return to sport following primary ACL reconstruction (ACLR group) and 47 uninjured control individuals (17.0 years) (CTRL group) participated. QF strength was assessed and Quadriceps Index calculated (QI = [involved strength/uninvolved strength]*100%). The ACLR group was sub-divided based on QI: High Quadriceps (HQ, QI≥90%) and Low-Quadriceps (LQ, QI<85%). Knee kinematic and kinetic variables were collected during a drop vertical jump maneuver. Limb symmetry during landing, and discrete variables were compared among the groups with multivariate analysis of variance and linear regression analyses. Results The LQ group demonstrated worse asymmetry in all kinetic and ground reaction force variables compared to the HQ and CTRL groups, including reduced involved limb peak knee external flexion moments (p<.001), reduced involved limb (p=.003) and increased uninvolved limb (p=.005) peak vertical ground reaction forces, and higher uninvolved limb peak loading rates (p<.004). There were no differences in the landing patterns between the HQ and CTRL groups on any variable (p>.05). In the ACLR group, QF strength estimated limb symmetry during landing after controlling for graft type, meniscus injury, knee pain and symptoms. Conclusion At the time of return to sport, individuals post-ACL reconstruction with weaker QF demonstrate altered landing patterns. Conversely, those with nearly symmetrical QF strength demonstrate landing patterns similar to uninjured individuals. Consideration of an objective QF strength measure may aid clinical decision-making to optimize sports participation following ACL

  17. The ACL Message Passing Library

    SciTech Connect

    Painter, J.; McCormick, P.; Krogh, M.; Hansen, C.; Colin de Verdiere, G.

    1995-09-01

    This paper presents the ACL (Advanced Computing Lab) Message Passing Library. It is a high throughput, low latency communications library, based on Thinking Machines Corp.`s CMMD, upon which message passing applications can be built. The library has been implemented on the Cray T3D, Thinking Machines CM-5, SGI workstations, and on top of PVM.

  18. Diagnostic Value of Knee Arthrometry in the Prediction of Anterior Cruciate Ligament Strain During Landing

    PubMed Central

    Kiapour, Ata M.; Wordeman, Samuel C.; Paterno, Mark V.; Quatman, Carmen E.; Levine, Jason W.; Goel, Vijay K.; Demetropoulos, Constantine K.; Hewett, Timothy E.

    2014-01-01

    Background Previous studies have indicated that higher knee joint laxity may be indicative of an increased risk of anterior cruciate ligament (ACL) injuries. Despite the frequent clinical use of knee arthrometry in the evaluation of knee laxity, little data exist to correlate instrumented laxity measures and ACL strain during dynamic high-risk activities. Purpose/Hypotheses The purpose of this study was to evaluate the relationships between ACL strain and anterior knee laxity measurements using arthrometry during both a drawer test and simulated bipedal landing (as an identified high-risk injurious task). We hypothesized that a high correlation exists between dynamic ACL strain and passive arthrometry displacement. The secondary hypothesis was that anterior knee laxity quantified by knee arthrometry is a valid predictor of injury risk such that specimens with greater anterior knee laxity would demonstrate increased levels of peak ACL strain during landing. Study Design Controlled laboratory study. Methods Twenty cadaveric lower limbs (mean age, 46 ± 6 years; 10 female and 10 male) were tested using a CompuKT knee arthrometer to measure knee joint laxity. Each specimen was tested under 4 continuous cycles of anterior-posterior shear force (±134 N) applied to the tibial tubercle. To quantify ACL strain, a differential variable reluctance transducer (DVRT) was arthroscopically placed on the ACL (anteromedial bundle), and specimens were retested. Subsequently, bipedal landing from 30 cm was simulated in a subset of 14 specimens (mean age, 45 ± 6 years; 6 female and 8 male) using a novel custom-designed drop stand. Changes in joint laxity and ACL strain under applied anterior shear force were statistically analyzed using paired sample t tests and analysis of variance. Multiple linear regression analyses were conducted to determine the relationship between anterior shear force, anterior tibial translation, and ACL strain. Results During simulated drawer tests, 134 N

  19. Sex-specific gait adaptations prior to and up to six months after ACL reconstruction

    PubMed Central

    Stasi, Stephanie L. Di; Hartigan, Erin H.; Snyder-Mackler, Lynn

    2015-01-01

    STUDY DESIGN Controlled longitudinal laboratory study. OBJECTIVES Compare sagittal plane gait mechanics of men and women before and up to 6 months after anterior cruciate ligament reconstruction (ACLR). BACKGROUND Aberrant gait patterns are ubiquitous after anterior cruciate ligament (ACL) rupture and persist after ACLR despite skilled physical therapy. Sex influences post-operative function and second ACL injury risk, but its influence on gait adaptations after injury have not been investigated. METHODS Sagittal plane knee and hip joint excursions during midstance and internal knee and hip extension moments at peak knee flexion were collected on 12 women and 27 men using 3-dimensional gait analysis before (Screen) and after pre-operative physical therapy (Pre-sx), and 6 months after ACLR (6mo). Repeated measures analysis of variance models were used to determine whether limb asymmetries changed differently over time in men and women. RESULTS Significant time x limb x sex interactions were identified for hip and knee excursions and internal knee extension moments (P≤.007). Both sexes demonstrated smaller knee excursions on the involved compared to the uninvolved knee at each time point (P≤.007), but only women demonstrated a decrease in the involved knee excursion from pre-sx to 6mo (P=.03). Women also demonstrated smaller hip excursions (P<.001) and internal knee extension moments (P=.005) on the involved limb compared to the uninvolved limb at 6mo. Men demonstrated smaller hip excursions and knee moments on the involved limb compared to the uninvolved limb (main effects, P<.001). CONCLUSION The persistence of limb asymmetries in men and women 6 months after ACLR indicates that current rehabilitation efforts are inadequate for some individuals following ACLR. PMID:25627155

  20. News You Can Use: The Knee Anterolateral Ligament and the ISAKOS Journal.

    PubMed

    Lubowitz, James H; Provencher, Matthew T; Rossi, Michael J; Brand, Jefferson C

    2016-05-01

    The knee anterolateral ligament may be fiction, but we thought it fact. As true anatomic restoration of the anterior cruciate ligament (ACL) may not be possible today, we are open to the possibility that lateral augmentation of ACL reconstruction could be of benefit in some patients. PMID:27151446

  1. Gait modification strategies of trunk over left stance phase in patients with right anterior cruciate ligament deficiency

    PubMed Central

    Shi, Dongliang; Li, Nannan; Wang, Yubin; Jiang, Shuyun; Li, Jinglong; Zhu, Wenhui

    2015-01-01

    Purpose: To investigate the gait modification strategies of trunk over left stance phase in patients with right anterior cruciate ligament deficiency (ACL-D). Methods: Thirty-six patients with right ACL-D and thirty-six health subjects (control) were recruited to undergo a 3-dimensional (3D) gait analysis. Coordinate data from 26 reflective markers positioned on the body surface of participants were recorded with a 3D optical video motion capture system, as they walked on the ground, ascended and descended a custom-built staircase. Angle changes in the 3-planes under different walking conditions were analyzed. Results: There were statistically significant differences between the two groups in the trunk at the transverse plane angle in most measurements. With the walk pattern of stair descent, the trunk at all 3-plane angles, at the maximum value of the left knee sagittal/coronal/transverse plane moment, was significantly different between the two groups (P ≤ 0.03). Conclusions: Our findings suggested that special gait modification of trunk is apparent over stance of left (healthy) side in patients with right ACL-D. The results of this study may supply more insight with respect to improving the diagnosis and rehabilitation of ACL-D. This information may also be helpful for a better use of walk and stair tasks as part of a rehabilitation program and provide a safe guideline for the patients. PMID:26550279

  2. Knee injuries in female athletes.

    PubMed

    Hutchinson, M R; Ireland, M L

    1995-04-01

    Female athletes are at increased risk for certain sports-related injuries, particularly those involving the knee. Factors that contribute to this increased risk are the differences in sports undertaken and in gender anatomy and structure. Gender differences include baseline level of conditioning, lower extremity alignment, physiological laxity, pelvis width, tibial rotation and foot alignment. Sports like gymnastics and cheerleading create a noncontact environment, but can result in significant knee injuries. In quick stopping and cutting sports, females have an increased incidence of anterior cruciate ligament (ACL) injury by noncontact mechanisms. Patellofemoral (PF) disorders are also very common in female athletes. Awareness of these facts helps the sports medicine professional make an accurate diagnosis and institute earlier treatment-focused rehabilitation with or without surgery. Further prospective and retrospective research is needed in areas of epidemiology, mechanisms, severity and types of knee injuries. The goal is to lessen the severity of certain knee injuries and to prevent others. PMID:7604201

  3. Quadriceps function relates to muscle size following ACL reconstruction.

    PubMed

    Kuenze, Christopher M; Blemker, Silvia S; Hart, Joseph M

    2016-09-01

    It remains unclear what role reduced volume and cross-section area (CSA) of individual quadriceps muscles may play in persistent quadriceps weakness and more global dysfunction following ACL reconstruction (ACLR). The purpose of this investigation was to establish the relationship between cross-sectional area of the quadriceps muscle group and measures of knee related and quadriceps function following ACLR. Thirty participants with a history of primary, unilateral ACLR experiencing persistent quadriceps activation failure participated in this cohort study. Clinical factors including International Knee Documentation Committee (IKDC) score, normalized knee extension MVIC torque (Nm/kg) and quadriceps central activation ratio (CAR, %) were assessed in addition to CSA. Quadriceps CSA was measured via magnetic resonance imaging (MRI; Siemens Avanto 1.5T). Quadriceps CSA (cm(2) ) and quadriceps volume (cm(3) ) as well as individual muscle estimates were identified within a 10 cm mid-thigh capture area. Pearson's product-moment correlation coefficients (r) established relationships between CSA and all other variables. Stepwise linear regression established which CSA factors were able to successfully predict clinical factors. Knee extension MVIC torque was strongly correlated with Vastus Intermedius (VI; r =  0.857, p < 0.001) CSA as well as partial VI (r = 0.849, p < 0.001) and quadriceps (r = 0.830, p < 0.001) volume. Partial VI (r = 0.365, p = 0.047) volume was weakly correlated with IKDC score. Knee extension MVIC torque was strongly predicted using VI CSA alone (R(2)  = 0.725) or in combination with Vastus Medialis CSA (VM; R(2)  = 0.756). Statement of Clinical Significance: Atrophy of the VI and VM muscles negatively impacts knee extension strength following ACLR. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1656-1662, 2016. PMID:26763833

  4. Fifteen Year Prospective Comparison of Patellar & Hamstring Tendon Grafts for ACL Reconstruction

    PubMed Central

    Roe, Justin; Salmon, Lucy; Kok, Alison; Linklater, James; Pinczewski, Leo

    2016-01-01

    Objective: This prospective longitudinal study compares isolated endoscopic ACL reconstruction utilizing 4-strand hamstring tendon (HT) or patellar tendon (PT) autograft over a 15-year period with respect to clinical outcomes and the development of osteoarthritis. Method: 90 consecutive patients with isolated ACL rupture were reconstructed with a PT autograft and 90 patients received HT autograft, with an identical surgical technique. Patients were assessed at 2, 5, 7, 10 and 15 years. Assessment included the IKDC Knee Ligament Evaluation including radiographic evaluation, KT1000, kneeling pain, and clinical outcomes. Results: Subjects who received the PT graft had significantly worse outcomes at 15 years for the variables of radiologically detectable osteoarthritis (p=0.001), motion loss (p=0.02), single leg hop test (p=0.002), participation in strenuous activity (p=0.03), knee related decrease in activity level (p=0.002) and kneeling pain (p=0.03). There was no significant difference between the HT and PT groups in overall IKDC grade (p=0.28). ACL graft rupture occurred in 16% of HT group and 8% of the PT group (p=0.10). Contralateral ACL rupture occurred in significantly more PT patients (24%) than HT patients (12%) (p=0.03). Conclusion: Significant differences have developed at 15 years after surgery which were not seen at earlier reviews. Compared to the HT Group, the PT group had significantly worse outcomes with respect to radiological osteoarthritis, range of motion and functional tests but no significant difference in laxity was identified. There was a high incidence of ACL injury after reconstruction, to both the reconstructed and the contralateral knee.

  5. PRP Augmentation for ACL Reconstruction

    PubMed Central

    Di Matteo, Berardo; Kon, Elizaveta; Marcacci, Maurilio

    2015-01-01

    Current research is investigating new methods to enhance tissue healing to speed up recovery time and decrease the risk of failure in Anterior Cruciate Ligament (ACL) reconstructive surgery. Biological augmentation is one of the most exploited strategies, in particular the application of Platelet Rich Plasma (PRP). Aim of the present paper is to systematically review all the preclinical and clinical papers dealing with the application of PRP as a biological enhancer during ACL reconstructive surgery. Thirty-two studies were included in the present review. The analysis of the preclinical evidence revealed that PRP was able to improve the healing potential of the tendinous graft both in terms of histological and biomechanical performance. Looking at the available clinical evidence, results were not univocal. PRP administration proved to be a safe procedure and there were some evidences that it could favor the donor site healing in case of ACL reconstruction with patellar tendon graft and positively contribute to graft maturation over time, whereas the majority of the papers did not show beneficial effects in terms of bony tunnels/graft area integration. Furthermore, PRP augmentation did not provide superior functional results at short term evaluation. PMID:26064903

  6. PRP Augmentation for ACL Reconstruction.

    PubMed

    Andriolo, Luca; Di Matteo, Berardo; Kon, Elizaveta; Filardo, Giuseppe; Venieri, Giulia; Marcacci, Maurilio

    2015-01-01

    Current research is investigating new methods to enhance tissue healing to speed up recovery time and decrease the risk of failure in Anterior Cruciate Ligament (ACL) reconstructive surgery. Biological augmentation is one of the most exploited strategies, in particular the application of Platelet Rich Plasma (PRP). Aim of the present paper is to systematically review all the preclinical and clinical papers dealing with the application of PRP as a biological enhancer during ACL reconstructive surgery. Thirty-two studies were included in the present review. The analysis of the preclinical evidence revealed that PRP was able to improve the healing potential of the tendinous graft both in terms of histological and biomechanical performance. Looking at the available clinical evidence, results were not univocal. PRP administration proved to be a safe procedure and there were some evidences that it could favor the donor site healing in case of ACL reconstruction with patellar tendon graft and positively contribute to graft maturation over time, whereas the majority of the papers did not show beneficial effects in terms of bony tunnels/graft area integration. Furthermore, PRP augmentation did not provide superior functional results at short term evaluation. PMID:26064903

  7. Basic biomechanic principles of knee instability.

    PubMed

    Zlotnicki, Jason P; Naendrup, Jan-Hendrik; Ferrer, Gerald A; Debski, Richard E

    2016-06-01

    Motion at the knee joint is a complex mechanical phenomenon. Stability is provided by a combination of static and dynamic structures that work in concert to prevent excessive movement or instability that is inherent in various knee injuries. The anterior cruciate ligament (ACL) is a main stabilizer of the knee, providing both translational and rotatory constraint. Despite the high volume of research directed at native ACL function, pathogenesis and surgical reconstruction of this structure, a gold standard for objective quantification of injury and subsequent repair, has not been demonstrated. Furthermore, recent studies have suggested that novel anatomic structures may play a significant role in knee stability. The use of biomechanical principles and testing techniques provides essential objective/quantitative information on the function of bone, ligaments, joint capsule, and other contributing soft tissues in response to various loading conditions. This review discusses the principles of biomechanics in relation to knee stability, with a focus on the objective quantification of knee stability, the individual contributions of specific knee structures to stability, and the most recent technological advances in the biomechanical evaluation of the knee joint. PMID:27007474

  8. Direct Visualization of Existing Footprint and Outside-In Drilling of the Femoral Tunnel in Anterior Cruciate Ligament Reconstruction in the Knee

    PubMed Central

    Sutter, E. Grant; Anderson, John A.; Garrett, William E.

    2015-01-01

    Improper femoral tunnel placement in anterior cruciate ligament (ACL) reconstruction is a significant problem and may be a cause of ACL graft failure and abnormal kinematics, which may lead to late degenerative changes after reconstruction. Recently, there has been concern that the transtibial approach may contribute to nonanatomic placement of the femoral tunnel, resulting in abnormal knee kinematics. Tibial-independent techniques can provide more anatomic placement of the ACL graft, but these can be technically demanding. This technical note describes the senior author's technique to directly identify the femoral ACL remnant and use the center of the femoral ACL footprint and retrograde drilling to create an anatomic femoral socket for single-bundle reconstruction. This technique provides femoral tunnel placement based on identification of a patient-specific ACL footprint instead of averaged anatomic measurements from large groups. This technique has been shown to produce anatomic ACL graft position and orientation and restore more normal knee kinematics. PMID:26052485

  9. Operative and nonoperative treatment options for ACL tears in the adult patient: a conceptual review.

    PubMed

    Bogunovic, Ljiljana; Matava, Matthew J

    2013-11-01

    Injury to the anterior cruciate ligament (ACL) is common among athletic individuals. Both nonoperative and operative treatment options exist. The optimal treatment of an adult with an ACL tear depends on several patient-specific factors, including age, occupation, and desired activity level. In less active patients with sedentary jobs, nonoperative management, consisting of physical therapy, bracing, and activity modification can yield successful results. In active patients who want to resume participation in jumping, cutting, or pivoting sports, patients who have physically demanding occupations, or patients who fail a trial of nonoperative management, ACL reconstruction is recommended. Reconstruction utilizing autograft tissue is preferred over allograft, especially in the younger athlete, but allograft tissue is a reasonable option in the older (aged > 40 years) and less active adult, as well. Successful results have been achieved with both patellar tendon and hamstring grafts. The optimal treatment in adult patients with ACL tears should be based on careful consideration of the patient's goals for return to activity, knee-specific comorbidities, such as coexistent meniscal pathology or osteoarthritis, and his or her willingness to follow a detailed rehabilitation regimen. Our article provides an overview of current nonoperative and operative treatment options for adults with ACL tears, considers the outcomes of both nonoperative and operative strategies, and provides general recommendations as to the ideal management for a given patient. PMID:24231595

  10. Effects of ACL Reconstructive Surgery on Temporal Variations of Cytokine Levels in Synovial Fluid

    PubMed Central

    Bigoni, Marco; Gandolla, Marta; Sacerdote, Paola; Piatti, Massimiliano; Castelnuovo, Alberto; Franchi, Silvia; Gorla, Massimo; Munegato, Daniele; Gaddi, Diego; Pedrocchi, Alessandra; Omeljaniuk, Robert J.; Locatelli, Vittorio; Torsello, Antonio

    2016-01-01

    Anterior cruciate ligament (ACL) reconstruction restores knee stability but does not reduce the incidence of posttraumatic osteoarthritis induced by inflammatory cytokines. The aim of this research was to longitudinally measure IL-1β, IL-6, IL-8, IL-10, and TNF-α levels in patients subjected to ACL reconstruction using bone-patellar tendon-bone graft. Synovial fluid was collected within 24–72 hours of ACL rupture (acute), 1 month after injury immediately prior to surgery (presurgery), and 1 month thereafter (postsurgery). For comparison, a “control” group consisted of individuals presenting chronic ACL tears. Our results indicate that levels of IL-6, IL-8, and IL-10 vary significantly over time in reconstruction patients. In the acute phase, the levels of these cytokines in reconstruction patients were significantly greater than those in controls. In the presurgery phase, cytokine levels in reconstruction patients were reduced and comparable with those in controls. Finally, cytokine levels increased again with respect to control group in the postsurgery phase. The levels of IL-1β and TNF-α showed no temporal variation. Our data show that the history of an ACL injury, including trauma and reconstruction, has a significant impact on levels of IL-6, IL-8, and IL-10 in synovial fluid but does not affect levels of TNF-α and IL-1β. PMID:27313403

  11. USE OF SPATIOTEMPORAL GAIT PARAMETERS TO DETERMINE RETURN TO SPORTS AFTER ACL RECONSTRUCTION

    PubMed Central

    LEPORACE, GUSTAVO; METSAVAHT, LEONARDO; ZEITOUNE, GABRIEL; MARINHO, THIAGO; OLIVEIRA, TAINÁ; PEREIRA, GLAUBER RIBEIRO; OLIVEIRA, LISZT PALMEIRA DE; BATISTA, LUIZ ALBERTO

    2016-01-01

    Objective : To compare gait spatiotemporal parameters of healthy and ACL reconstructed subjects in order to classify the status of gait normality. Methods : Fourteen healthy subjects and eight patients submitted to ACL reconstruction walked along a walkway while the lower limbs movement was captured by an infrared camera system. The frames where the initial contact and toe-off took place were determined and the following dependent variables, which were compared between groups through the Mann-Whitney test (a=0.05) were calculated: percentage of time in initial double stance, percentage of time in single stance, percentage of time in terminal double stance, stride length and gait velocity. Initially, all variables were compared between groups using a Mann-Whitney test. A logistic regression was applied, including all dependent variables, to create a model that could differentiate healthy and ACL reconstructed subjects. Results : ACL reconstructed group showed no differences in any spatiotemporal parameter of gait (p > 0.05) in relation to the control group, although the angular kinematic differences of the knee remained altered, as evidenced in a study with a similar sample. Conclusion : The regression classified all subjects as healthy, including the ACL reconstructed group, suggesting the spatiotemporal variables should not be used as the sole criterion of return to sports activities at the same level as prior to injury. Level of Evidence III, Case Control Study. PMID:26981039

  12. Surgical Predictors of Clinical Outcome following Revision ACL Reconstruction

    PubMed Central

    Wright, Rick W.

    2016-01-01

    .05). Using a metal interference screw for current femoral fixation resulted in significantly better outcomes in 2 year KOOS symptoms, pain, and QOL subscales (OR range = 0.51-0.59; 95% CI=0.30-1.00; p<0.05), as well as WOMAC stiffness (OR=0.57; 95% CI=0.33-0.98; p=0.041). Avoiding a notchplasty significantly improved 2 year outcomes of the IKDC (OR=1.47; 95% CI=1.08-1.99; p=0.013), KOOS ADL and QOL subscales (OR range = 1.40-1.41; 95% CI=1.03-1.93; p<0.04), and the WOMAC stiffness and ADL subscales (OR range = 1.41-1.49; 95% CI=1.03-2.05; p<0.04). Lower baseline outcome scores, activity level, higher BMI, female gender, and shorter time since the patient’s last ACL reconstruction all significantly increased the odds of reporting poorer clinical outcomes at 2 years. Prior femoral fixation, prior femoral aperture position, and the knee flexion angle at the time of graft fixation were not found to be significant risk factors for 2 year outcomes in this revision cohort. Conclusion: There are surgical variables that the physician can control at the time of an ACL revision which have the ability to modify clinical outcomes at 2 years. Whenever possible, opting for an anteromedial portal or transtibial surgical exposure, choosing a metal inference screw for femoral fixation, not performing a notchplasty, and not using a biologic enhancement will improve the patient’s odds of having a significantly better 2 year clinical outcomes.

  13. Functional knee assessment with advanced imaging.

    PubMed

    Amano, Keiko; Li, Qi; Ma, C Benjamin

    2016-06-01

    The purpose of anterior cruciate ligament (ACL) reconstruction is to restore the native stability of the knee joint and to prevent further injury to meniscus and cartilage, yet studies have suggested that joint laxity remains prevalent in varying degrees after ACL reconstruction. Imaging can provide measurements of translational and rotational motions of the tibiofemoral joint that may be too small to detect in routine physical examinations. Various imaging modalities, including fluoroscopy, computed tomography (CT), and magnetic resonance imaging (MRI), have emerged as powerful methods in measuring the minute details involved in joint biomechanics. While each technique has its own strengths and limitations, they have all enhanced our understanding of the knee joint under various stresses and movements. Acquiring the knowledge of the complex and dynamic motions of the knee after surgery would help lead to improved surgical techniques and better patient outcomes. PMID:27052009

  14. ACL reconstruction with BPTB autograft and irradiated fresh frozen allograft*

    PubMed Central

    Sun, Kang; Tian, Shao-qi; Zhang, Ji-hua; Xia, Chang-suo; Zhang, Cai-long; Yu, Teng-bo

    2009-01-01

    Objective: To analyze the clinical outcomes of arthroscopic anterior cruciate ligament (ACL) reconstruction with irradiated bone-patellar tendon-bone (BPTB) allograft compared with non-irradiated allograft and autograft. Methods: All BPTB allografts were obtained from a single tissue bank and the irradiated allografts were sterilized with 2.5 mrad of irradiation prior to distribution. A total of 68 patients undergoing arthroscopic ACL reconstruction were prospectively randomized consecutively into one of the two groups (autograft and irradiated allograft groups). The same surgical technique was used in all operations done by the same senior surgeon. Before surgery and at the average of 31 months of follow-up (ranging from 24 to 47 months), patients were evaluated by the same observer according to objective and subjective clinical evaluations. Results: Of these patients, 65 (autograft 33, irradiated allograft 32) were available for full evaluation. When the irradiated allograft group was compared to the autograft group at the 31-month follow-up by the Lachman test, the anterior drawer test (ADT), the pivot shift test, and KT-2000 arthrometer test, statistically significant differences were found. Most importantly, 87.8% of patients in the autograft group and just only 31.3% in the irradiated allograft group had a side-to-side difference of less than 3 mm according to KT-2000. The failure rate of the ACL reconstruction with irradiated allograft (34.4%) was higher than that with autograft (6.1%). The anterior and rotational stabilities decreased significantly in the irradiated allograft group. According to the overall International Knee Documentation Committee (IKDC), functional and subjective evaluations, and activity level testing, no statistically significant differences were found between the two groups. Besides, patients in the irradiated allograft group had a shorter operation time and a longer duration of postoperative fever. When the patients had a fever, the

  15. Accuracy and repeatability of Roentgen stereophotogrammetric analysis (RSA) for measuring knee laxity in longitudinal studies.

    PubMed

    Fleming, B C; Peura, G D; Abate, J A; Beynnon, B D

    2001-10-01

    Roentgen stereophotogrammetric analysis (RSA) can be used to assess temporal changes in anterior-posterior (A-P) knee laxity. However, the accuracy and precision of RSA is dependent on many factors and should be independently evaluated for a particular application. The objective of this study was to evaluate the use of RSA for measuring A-P knee laxity. The specific aims were to assess the variation or "noise" inherent to RSA, to determine the reproducibility of RSA for repeated A-P laxity testing, and to assess the accuracy of these measurements. Two experiments were performed. The first experiment utilized three rigid models of the tibiofemoral joint to assess the noise and to compare digitization errors of two independent examiners. No differences were found in the kinematic outputs of the RSA due to examiner, repeated trials, or the model used. In a second experiment, A-P laxity values between the A-P shear load limits of +/-60 N of five cadaver goat knees were measured to assess the error associated with repeated testing. The RSA laxity values were also compared to those obtained from a custom designed linkage system. The mean A-P laxity values with the knee 30 degrees, 60 degrees, and 90 degrees of flexion for the ACL-intact goat knee (+/-95% confidence interval) were 0.8 (+/-0.25), 0.9 (+/-0.29), and 0.4 (+/-0.22) mm, respectively. In the ACL-deficient knee, the A-P laxity values increased by an order of magnitude to 8.8 (+/-1.39), 7.6 (+/-1.32), and 3.1 (+/-1.20)mm, respectively. No significant differences were found between the A-P laxity values measured by RSA and the independent measurement technique. A highly significant linear relationship (r(2)=0.83) was also found between these techniques. This study suggests that the RSA method is an accurate and precise means to measure A-P knee laxity for repeated testing over time. PMID:11522316

  16. Sex Differences in Proximal Control of the Knee Joint

    PubMed Central

    Mendiguchia, Jurdan; Ford, Kevin R.; Quatman, Carmen E.; Alentorn-Geli, Eduard; Hewett, Timothy E.

    2014-01-01

    Following the onset of maturation, female athletes have a significantly higher risk for anterior cruciate ligament (ACL) injury compared with male athletes. While multiple sex differences in lower-extremity neuromuscular control and biomechanics have been identified as potential risk factors for ACL injury in females, the majority of these studies have focused specifically on the knee joint. However, increasing evidence in the literature indicates that lumbopelvic (core) control may have a large effect on knee-joint control and injury risk. This review examines the published evidence on the contributions of the trunk and hip to knee-joint control. Specifically, the sex differences in potential proximal controllers of the knee as risk factors for ACL injury are identified and discussed. Sex differences in trunk and hip biomechanics have been identified in all planes of motion (sagittal, coronal and transverse). Essentially, female athletes show greater lateral trunk displacement, altered trunk and hip flexion angles, greater ranges of trunk motion, and increased hip adduction and internal rotation during sport manoeuvres, compared with their male counterparts. These differences may increase the risk of ACL injury among female athletes. Prevention programmes targeted towards trunk and hip neuromuscular control may decrease the risk for ACL injuries. PMID:21688868

  17. Anatomic Double Bundle single tunnel Foreign Material Free ACL-Reconstruction – a technical note

    PubMed Central

    Felmet, Gernot

    2011-01-01

    Summary The anterior cruciate ligament (ACL) consists of two bundles, the anteromedial (AM) and posterolateral bundle (PM). Double bundle reconstructions appear to give better rotational stability. The usual technique is to make two tunnels in the femur and two in the tibia. This is difficult and in small knees may not even be possible. We have developed a foreign material free press fit fixation for double bundle ACL reconstruction using a single femoral tunnel (R). This is based on the ALL PRESS FIT ACL reconstruction. It is suitable for the most common medium and, otherwise difficult, small sizes of knees. Method: Using diamond edged wet grinding hollow reamers, bone cylinders in different diameters are harvested from the implantation tunnels of the tibia and femur and used for the press fit fixation. Using the press fit technique the graft is first fixed in tibia. It is then similarly fixed under tension in the femoral side with the knee in 120 degree flexion. This is called Bottom To Top Fixation (BTT). On extending the knee the graft tension is self adapting. Depending on the size of the individual knee, the diameter of the femoral bone plug is varied from 8 to 13 mm to achieve an anatomic spread with a double bundle-like insertion. The tibia tunnel can be applied with two 7 or 8 mm diameter tunnels overlapping to a semi oval tunnel between 10 to 13 mm. Results: Since May 2003 we have carried out ACL-reconstructions with Hamstring grafts without foreign material using the ALL PRESS FIT technique. Initially, an 8 mm press fit fixation was used proximally with good results. Since April 2008, the range of diameters was increased up to 13 mm. The results of the Lachman tests have been good to excellent. Results of the Pivot shift test suggested more stability with femoral broader diameters of 9,5 to 13 mm. Conclusions: The foreign material free fixation of ham-string in the ALL PRESS FIT Bottom To Top Fixation is a successful method for ACL Reconstruction. The

  18. THE INFLUENCE OF SEX AND MATURATION ON LANDING BIOMECHANICS: IMPLICATIONS FOR ACL INJURY

    PubMed Central

    Sigward, S. M.; Pollard, C. D.; Powers, C. M.

    2010-01-01

    During landing and cutting, females exhibit greater frontal plane moments at the knee (internal knee adductor moments or external knee abduction moments) and favor use of the knee extensors over the hip extensors to attenuate impact forces when compared to males. However, it is not known when this biomechanical profile emerges. The purpose of this study was to compare landing biomechanics between sexes across maturation levels. One hundred and nineteen male and female soccer players (9–22 years) participated. Subjects were grouped based on maturational development. Lower extremity kinematics and kinetics were obtained during a drop-land task. Dependent variables included the average internal knee adductor moment and sagittal plane knee/hip moment and energy absorption ratios during the deceleration phase of landing. When averaged across maturation levels, females demonstrated greater internal knee adductor moments (0.06±0.03 vs. 0.01±0.02 Nm/kg*m; P<0.005), knee/hip extensor moment ratios (2.0±0.1 vs. 1.4±0.1 Nm/kg*m; P<0.001), and knee/hip energy absorption ratios (2.9±0.1 vs. 1.96±0.1 Nm/kg*m; P<0.001) compared to males. Higher knee adductor moments combined with disproportionate use of knee extensors relative to hip extensors observed in females reflects a biomechanical pattern that increases ACL loading. This biomechanical strategy already was established in pre-pubertal female athletes. PMID:21210853

  19. ALL‐EPIPHYSEAL ACL RECONSTRUCTION: A THREE‐YEAR FOLLOW‐UP

    PubMed Central

    Akinleye, Sheriff D.; Sewick, Amy

    2013-01-01

    Background/Introduction: With an increasing number of pre‐adolescents participating in sports, anterior cruciate ligament injuries and resultant reconstruction in the skeletally immature athlete are becoming more common. Many different surgical techniques and rehabilitation protocols have been proposed for the treatment of anterior cruciate ligament (ACL) injuries, but there is a lack of agreement as to which approach results in the best outcome. Rehabilitation protocols have marked variation regarding postoperative weight bearing, immobilization, bracing, and length. Case description: This is a case of a ten year old female who sustained bilateral ACL tears within the period of a year. The purpose of this case report is to describe the early result and subsequent rehabilitation following bilateral physeal‐sparing all‐epiphyseal ACL reconstructions on a skeletally immature patient with a three‐year follow‐up. Outcomes: The early post‐surgical recovery period on the first injured knee was complicated by knee stiffness requiring manipulation. Following this minor setback, the patient met all physical therapy goals and had no additional complications. The rehabilitation after the second surgery followed a typical course. At three‐year follow‐up, the patient had grown an additional seven inches, with radiographic evidence of symmetric physeal growth and joint stability. She has returned to playing competitive sports. Discussion and Conclusion: This innovative physeal‐sparing technique has huge implications as, historically; the feared complication of growth disturbance and angular deformity from transphyseal ACL reconstruction has complicated the management of ACL injuries in children and pre‐adolescents. This case report demonstrates the success of this technique, and the subsequent rehabilitation, as this patient did not experience a reduction in long‐term bone growth. Level of Evidence: 5 Case Report PMID:23772346

  20. Prediction of Patient-Reported Outcome After Single-Bundle ACL Reconstruction

    PubMed Central

    Kowalchuk, Deborah A.; Harner, Christopher D.; Fu, Freddie H.; Irrgang, James J.

    2010-01-01

    Purpose To identify pre-operative and intra-operative factors that predict patient-oriented outcome as measured by the IKDC Subjective Knee Form after ACL reconstruction. Methods We identified 402 subjects who had undergone primary single-bundle arthroscopic ACL reconstruction at a mean follow-up of 6.3 years (range 2-15 years). The International Knee Documentation Committee Subjective Knee Form (IKDC) was used to measure patient-reported outcome and was dichotomized as above or below the patient-specific age and gender matched population average. Potential predictor variables included subject demographics, activity level prior to surgery, previous meniscectomy, and surgical variables. Multivariate logistic regression analysis was performed to identify the best subset of predictors for determining the likelihood that the IKDC score was better than the age- and sex-matched population average. Results The dichotomized IKDC score was associated with BMI, smoking status, education, previous medial meniscectomy, and medial chondrosis at the time of ACL reconstruction. The multivariate model containing only factors known before surgery included BMI and smoking status. Subjects with a BMI > 30 had 0.35 times the odds of success than subjects with a normal BMI. Subjects who smoked had 0.36 times the odds of success as subjects who did not smoke. A model including medial chondrosis at the time of surgery had a slightly higher discriminatory power (area under the ROC curve 0.65 versus 0.61) and negative predictive value (71.4 versus 60.0), but similar positive predictive power (86.3 versus 85.9). Conclusions Lower patient-reported outcome following ACL reconstruction was strongly associated with obesity, smoking, and severe chondrosis at time of surgery. PMID:19409302

  1. Anterolateral Ligament of the Knee: Back to the Future in Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Bonasia, Davide Edoardo; D’Amelio, Andrea; Pellegrino, Pietro; Rosso, Federica; Rossi, Roberto

    2015-01-01

    Although the importance of the anterolateral stabilizing structures of the knee in the setting of anterior cruciate ligament (ACL) injuries has been recognized since many years, most of orthopedic surgeons do not take into consideration the anterolateral structures when performing an ACL reconstruction. Anatomic single or double bundle ACL reconstruction will improve knee stability, but a small subset of patients may experience some residual anteroposterior and rotational instability. For this reason, some researchers have turned again towards the anterolateral aspect of the knee and specifically the anterolateral ligament. The goal of this review is to summarize the existing knowledge regarding the anterolateral ligament of the knee, including anatomy, histology, biomechanics and imaging. In addition, the most common anterolateral reconstruction/tenodesis techniques are described together with their respective clinical outcomes. PMID:26330991

  2. Knee Bracing: What Works?

    MedlinePlus

    MENU Return to Web version Knee Bracing: What Works? Knee Bracing: What Works? What are knee braces? Knee braces are supports ... have arthritis in their knees. Do knee braces work? Maybe. Companies that make knee braces claim that ...

  3. The mechanical consequences of dynamic frontal plane limb alignment for non-contact ACL injury.

    PubMed

    Chaudhari, Ajit M; Andriacchi, Thomas P

    2006-01-01

    This study investigated the mechanical consequences of differences in dynamic frontal plane alignment of the support limb and the influence of anticipatory muscle activation at the hip and ankle on reducing the potential for non-contact ACL injury during single-limb landing. A frontal plane, three-link passive dynamic model was used to estimate an ACL non-contact injury threshold. This threshold was defined as the maximum axial force that the knee could sustain before the joint opened 8 degrees either medially or laterally, which was deemed sufficient to cause injury. The limb alignment and hip and ankle muscle contractions were varied to determine their effects on the ACL injury threshold. Valgus or varus alignment reduced the injury threshold compared to neutral alignment, but increasing the anticipatory contraction of hip abduction and adduction muscle groups increased the injury threshold. Increasing anticipatory ankle inversion/eversion muscle contraction had no effect. This study provides a mechanical rationale for the conclusion that a neutral limb alignment (compared to valgus or varus) during landing and increasing hip muscle contraction (abductors/adductors) prior to landing can reduce the possibility of ACL rupture through a valgus or varus opening mechanism. PMID:16321635

  4. A Knee-Specific Finite Element Analysis of the Human Anterior Cruciate Ligament Impingement against the Femoral Intercondylar Notch

    PubMed Central

    Park, Hyung-Soon; Ahn, Chulhyun; Fung, David T.; Ren, Yupeng; Zhang, Li-Qun

    2010-01-01

    This work presents a finite element analysis of Anterior Cruciate Ligament (ACL) impingement against the intercondylar notch during tibial external rotation and abduction, as a mechanism of noncontact ACL injuries. Experimentally, ACL impingement was measured in a cadaveric knee in terms of impingement contact pressure and six degrees-of-freedom tibiofemoral kinematics. Three-dimensional geometries of the ACL, femur and tibia were incorporated into the finite element model of the individual knee specimen. A fiber-reinforced model was adopted, which accounts for the anisotropy, large deformation, nonlinearity and incompressibility of the ACL. With boundary conditions specified based on the experimental tibiofemoral kinematics, the finite element analysis showed that impingement between the ligament and the lateral wall of intercondylar notch could occur when the knee 45° was externally rotated at 29.1° and abducted at 10.0°. Strong contact pressure and tensile stress occurred at the impinging and nonimpinging sides of the ligament, respectively. The impingement force and contact area estimated from the model matched their counterparts from the corresponding cadaver experiment. The modeling and experimental approach provides a useful tool to characterize potential ACL impingement on a knee-specific basis, which may help elucidate the ACL injury mechanism and develop more effective treatments. PMID:20413123

  5. Synchronous quadriceps tendon rupture and unilateral ACL tear in a weightlifter, associated with anabolic steroid use.

    PubMed

    Fenelon, Christopher; Dalton, David M; Galbraith, John G; Masterson, Eric L

    2016-01-01

    Synchronous quadriceps tendon rupture is rare. A 29-year-old man, an amateur weight lifter, taking androgenic-anabolic steroids (AAS), developed sudden onset bilateral pain and swelling of his anterior thighs when attempting to squat 280 kg (620 lb). Examination revealed gross swelling superior to the patella and palpable gaps in both quadriceps tendons. He underwent successful operative repair. MRI revealed a partial tear of the anterior cruciate ligament (ACL) of the right knee. This was not reconstructed. Only a few case reports of the association between AAS and quadriceps rupture exist in the literature, with none to the best of our knowledge in the past 10 years. ACL rupture coexisting is very rare, with only two reported cases. PMID:27154985

  6. An integrated approach to change the outcome part I: neuromuscular screening methods to identify high ACL injury risk athletes.

    PubMed

    Myer, Gregory D; Ford, Kevin R; Brent, Jensen L; Hewett, Timothy E

    2012-08-01

    An important step for treatment of a particular injury etiology is the appropriate application of a treatment targeted to the population at risk. An anterior cruciate ligament (ACL) injury risk algorithm has been defined that employs field-based techniques in lieu of laboratory-based motion analysis systems to identify athletes with high ACL injury risk landing strategies. The resultant field-based assessment techniques, in combination with the developed prediction algorithm, allow for low-cost identification of athletes who may be at increased risk of sustaining ACL injury. The combined simplicity and accuracy of the field-based tool facilitate its use to identify specific factors that may increase risk of injury in female athletes. The purpose of this report is to demonstrate novel algorithmic techniques to accurately capture and analyze measures of knee valgus motion, knee flexion range of motion, body mass, tibia length and quadriceps to hamstrings ratio with video analysis software typically used by coaches, strength and conditioning specialists, and athletic trainers. The field-based measurements and software analyses were used in a prediction algorithm to identify those at potential risk of noncontact ACL injury that may directly benefit from neuromuscular training. PMID:22580976

  7. A Comparison of Dynamic Postural Stability Between Asymptomatic Controls and Male Patients One Year After ACL Reconstruction (Pilot Study)

    PubMed Central

    Ataoglu, Muhammed Baybars; Hazar, Zeynep; Kafa, Nihan; Özer, Mustafa; Citaker, Seyit

    2014-01-01

    Objectives: The purpose of this study was to determine if dynamic postural stability gained one year after ACL reconstruction in patients who received rehabilitation. Methods: Seven male patients (mean age=32,66 ±6,47) who had previously undergone ACL reconstruction (ACL-R) and 7 sex-and general physical activity matched uninjured controls included to study. Mean time since original injury was 13±3,31 months. Dynamic postural control was assessed with 20° knee flexion with Star Excursion Balance test. Each participant performed 3 trials of the anterior, posterior-medial, and posterior-lateral directional components of the SEBT. Reach distances for each directional component were compared with non-injured leg and healthy controls’. Results: There was no significant difference in all directions of Star Excursion Balance test between neither the operated and uninjured knees of patients nor between patients and healthy controls (p>0,05). Conclusion: No deficits in dynamic postural stability were present average one year after ACL reconstruction in patients who received rehabilitation. It can be said that rehabilitation is effective in the recovery of dynamic postural stability.

  8. Predictors of Activity Level Two years after ACL Reconstruction: MOON ACLR Cohort Study

    PubMed Central

    Dunn, Warren R.; Spindler, Kurt P.; Amendola, Annunziato; Andrish, Jack T.; Bergfeld, John A.; Flanigan, David C.; Jones, Morgan H.; Kaeding, Christopher C.; Marx, Robert G.; Matava, Matthew J.; McCarty, Eric C.; Parker, Richard D.; Wolcott, Michelle; Vidal, Armando; Wolf, Brian R.; Wright, Rick W.; Harrell, Frank E.; Dittus, Robert S.

    2013-01-01

    Objective ACL deficient subjects are at risk of knee injury with cutting and pivoting activities; in accord, ACL reconstructions (ACLR) are performed to restore stability to allow for return to cutting and pivoting activities. The Marx activity level is a validated patient-reported measure to quantify the amount and frequency of running, cutting, decelerating, and pivoting performed. Our objective was to quantify activity level 2 yrs after ACLR and identify explanatory variables measured at baseline (demographics, concomitant meniscal/articular cartilage injuries and their treatment) associated with activity level at short-term follow-up (2 yrs). Methods In 2002, the multicenter consortium began enrolling subjects undergoing ACLR at six recruitment sites. This ongoing multicenter cohort study targets follow-up at 2, 6, and 10 years. The current study reports two-year follow-up of subjects enrolled in 2002. Participants in the multicenter ACLR cohort completed a series of validated, patient-oriented questionnaires that included activity level assessment. Follow-up questionnaires were collected by mail between 1/01/04 and 6/01/05 to assess changes. Measurement of intraarticular pathology, techniques of ACLR, and secondary procedures were recorded at baseline by participating surgeons. Multivariable proportional odds ordinal logistic regression was used to assess predictors of activity level after adjusting for baseline patient characteristics. Interquartile range (IQR) odds ratios (OR) are given for continuous variables, IQROR demonstrate the effect of increasing a baseline variable from its first quartile to its third quartile. The fitted model that used OR to specify predicted probabilities of exceeding any activity level was translated into predicted mean activity level and is presented in a nomogram for more interpretability. Results Of the 446 subjects that underwent unilateral ACLR, follow-up was obtained on 393 (88%). The cohort is 56% male, median age 23 yrs

  9. Graft Diameter matters in Hamstring ACL reconstruction

    PubMed Central

    Clatworthy, Mark

    2016-01-01

    Objective: Recently techniques have been developed to increase graft diameter in hamstring ACL reconstruction with the hope to decrease graft failure. To date there is limited evidence to show that a smaller graft diameter results in a higher ACL failure rate. Method: The factors for failure in 1480 consecutive single surgeon hamstring ACL reconstructions were evaluated prospectively. Patients were followed for 2-15 years. A multivariate analysis was performed which looked at graft size, age, sex, time to surgery, meniscal integrity, meniscal repair and ACL graft placement to determine whether graft diameter matters in determining the failure of hamstring ACL reconstruction. Results: Graft diameters ranged from 6-10 mm. The mean graft diameter for all patients was 7.75 mm. 83 ACL reconstructions failed. The mean size of graft failures was 7.55 mm ACL reconstructions that failed had a significantly smaller hamstring graft diameter p=0.001. The Hazard Ratio for a smaller diameter graft is 0.517 p=<0.0001. For every 1 mm decrease in graft diameter there is a 48.3% higher chance of failure. The multivariate analysis showed a hazard ratio of 0.543 p=0.002. For every 1 mm decrease in graft diameter there is a 45.7% higher chance of failure. Conclusion: Smaller diameter hamstring grafts do have a higher failure rate. Grafts ≤ 7.5 mm had twice the failure rate of grafts ≥8 mm using a multivariate analysis for every 1 mm decrease in graft diameter there is a 45.7% higher chance of failure.

  10. Anterior cruciate ligament (ACL) injury - aftercare

    MedlinePlus

    ... side of your knee, such as during a football tackle Twist your knee Quickly stop moving and ... or turning Skiers and people who play basketball, football, or soccer are more likely to have this ...

  11. Reconstruction of the anterior cruciate ligament with the iliotibial band autograft in patients with chronic knee instability.

    PubMed

    Jørgensen, U; Bak, K; Ekstrand, J; Scavenius, M

    2001-05-01

    We performed combined internal and external anterior cruciate ligament (ACL) reconstruction with the iliotibial band autograft in 169 consecutive patients with chronic ACL insufficiency who were followed up for 24-61 months. Of these, 155 (91%) agreed to an additional independent observer follow-up after 24-92 months. Eight patients (5%) had sustained a rerupture/elongation of the graft and were operated on again; nine (6%) had sustained a tear of the contralateral ACL. Knee function and activity increased after the reconstruction. Lysholm scores improved from median 81 preoperatively to 99 at follow-up and Tegner scores from median 4 to 7. At follow-up 97 (71%) were active at the same level as prior to injury. In 17 of the 40 patients (12%) dropping to a lower activity level this was due to knee problems. The side-to-side difference in anterior-posterior knee laxity was more than 3 mm in 18 knees (13%) and more than 5 mm in 3 knees (2%). Including eight reruptures, this results in a "stability" failure rate of 8.8%. The overall IKCD rating showed normal knee function in 88 (73%) and nearly normal knee function in 30 (25%). Anterior knee pain was present in 14 (10%) of the patients at follow-up. Patients with isolated ACL injury had higher Lysholm scores and Tegner scores than patients with associated injuries. No clinical signs of varus knee development were seen. Of the 155 patients 94% would have the procedure repeated if necessary with the knowledge that they have today. The combined internal and external iliotibial band procedure can restore knee stability and function in the majority of chronic ACL-insufficient knees. PMID:11420786

  12. Patients With Isolated PCL Injuries Improve From Surgery as Much as Patients With ACL Injuries After 2 Years

    PubMed Central

    Owesen, Christian; Sivertsen, Einar Andreas; Engebretsen, Lars; Granan, Lars-Petter; Årøen, Asbjørn

    2015-01-01

    Background: Reports on outcome after posterior cruciate ligament (PCL) reconstruction often contain both isolated PCL and combined knee ligament injuries. This makes it difficult to conclude on the outcome after reconstruction of isolated PCL injuries. Purpose: To investigate the outcome after PCL reconstruction in patients with an isolated PCL injury and to compare this with the outcome of patients treated with reconstruction after isolated anterior cruciate ligament (ACL) injuries. Study Design: Cohort study; Level of evidence, 3. Methods: Seventy-one patients with an isolated PCL injury that was reconstructed surgically and who had registered in the Norwegian Knee Ligament Registry between 2004 and 2010 were included in this study. Patients with isolated ACL reconstructions (n = 9661) who had registered in the same period were included for comparison. Knee Injury and Osteoarthritis Outcome Score (KOOS) was used as the patient-reported outcome measure. Preoperative and 2-year postoperative KOOS scores were compared. Changes in KOOS score reported by the PCL patients were compared with changes reported by the ACL patients. Results: At the 2-year postoperative follow-up of the PCL-reconstructed patients, the patient-reported outcome was improved, measured by KOOS as follows: pain, 15.1 (95% CI, 8.5-21.8; P < .001); symptoms, 0.9 (95% CI, –6.6 to 8.3; P = .82); activities of daily living, 13.2 (95% CI, 6.6-13.9; P < .001); sports, 20.7 (95% CI, 11.8-29.4; P < .001); and quality of life, 26.6 (95% CI, 18.9-34.2; P < .001). According to the KOOS, the incremental improvements were similar for PCL and ACL patients. Time from injury to surgery was longer for the PCL patients compared with ACL patients (median, 21.5 vs 8.0 months; P < .001). Conclusion: Patients undergoing PCL reconstruction can expect the same improvements in KOOS score as patients undergoing ACL reconstruction. However, PCL patients start out with an inferior score on average and consequently end up

  13. Knee Replacement

    MedlinePlus

    ... doctor may recommend it if you have knee pain and medicine and other treatments are not helping you anymore. When you have a total knee replacement, the surgeon removes damaged cartilage and bone ...

  14. Knee Problems

    MedlinePlus

    ... cartilage, a tough, elastic material that helps absorb shock and allows the knee joint to move smoothly. ... The two menisci in each knee act as shock absorbers, cushioning the lower part of the leg ...

  15. Knee Injuries

    MedlinePlus

    ... Sprains A sprain means you've stretched or torn a ligament. Common knee sprains usually involve damage ... A strain means you've partly or completely torn a muscle or tendon. With knee strains, you ...

  16. Knee Extension Range of Motion at 4 Weeks Is Related to Knee Extension Loss at 12 Weeks After Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Noll, Sarah; Garrison, J. Craig; Bothwell, James; Conway, John E.

    2015-01-01

    Background: The anterior cruciate ligament (ACL) is commonly torn, and surgical reconstruction is often required to allow a patient to return to their prior level of activity. Avoiding range of motion (ROM) loss is a common goal, but little research has been done to identify when ROM loss becomes detrimental to a patient’s future function. Purpose: To determine whether there is a relationship between early knee side-to-side extension difference after ACL reconstruction and knee side-to-side extension difference at 12 weeks. The hypothesis was that early (within the first 8 weeks) knee side-to-side extension difference will be predictive of knee side-to-side extension difference seen at 12 weeks. Study Design: Cohort study; Level of evidence, 3. Methods: Knee side-to-side extension difference measures were taken on 74 patients undergoing ACL reconstruction rehabilitation at the initial visit and 4, 8, and 12 weeks postoperatively. Visual analog scores (VAS) and International Knee Documentation Committee (IKDC) scores were also recorded at these time frames. Results: There was a strong relationship between knee extension ROM at 4 and 12 weeks (r = 0.639, P < .001) and 8 and 12 weeks (r = 0.742, P < .001). When the variables of knee extension ROM at initial visit and 4 and 8 weeks were entered into a regression analysis, the predictor variable explained 61% (R2 = 0.611) of variance for knee extension ROM at 12 weeks, with 4 weeks (R2 = 0.259) explaining the majority of this variance. Conclusion: This study found that a patient’s knee extension at 4 weeks was strongly correlated with knee extension at 12 weeks. Clinical Relevance: This information may be useful for clinicians treating athletic patients who are anxious for return to sport by providing them an initial goal to work toward in hopes of ensuring successful rehabilitation of their knee. PMID:26675061

  17. Histopathological Evaluation of the Anterior Cruciate Ligament in Patients Undergoing Primary Total Knee Arthroplasty.

    PubMed

    Mont, Michael A; Elmallah, Randa K; Cherian, Jeffrey J; Banerjee, Samik; Kapadia, Bhaveen H

    2016-01-01

    This study assessed gross and histopathological ACL changes in arthritic knees (n=174) undergoing total knee arthroplasty. Histopathological changes were assessed and graded as absent (0), mild (1), moderate (2), or marked (3). These were correlated to demographic and clinical factors, and radiographic evaluations. The ACL was intact in 43, frayed in 85, torn in 15, and absent in 31 knees. Eighty-five percent had histological changes. Overall, there were significant associations between greater age and BMI, and histological changes. Grade IV knees had significantly greater calcium pyrophosphate deposits, microcyst formation, and number of pathologic changes. These correlations may aid decision-making when determining suitability for unicompartmental or bicruciate-retaining arthroplasties, though further studies should correlate these histological findings to mechanical and functional knee status. PMID:26239235

  18. NFL Combine Athletic Performance after ACL Reconstruction

    PubMed Central

    Marshall, Nathan E.; Keller, Robert A.; Mehran, Nima; Austin, William; Moutzouros, Vasilios

    2016-01-01

    Objectives: The purpose of this study was to determine the functional performance of NFL combine participants after ACL reconstruction compared with an age-, size-, and position-matched control group. The hypothesis was that there would be no difference between players after ACL reconstruction as compared with controls in functional athletic performance. Methods: A total of 98 NFL-caliber athletes who had undergone primary ACL reconstruction and participated in the NFL scouting combine between 2010 and 2014 were reviewed and compared with an age-, size-, and position-matched control group. Data recorded for each player included a 40-yard dash, vertical leap, broad jump, shuttle drill, and 3-cone drill. Results: With regard to speed and acceleration, the mean 40-yard dash time for ACL-reconstructed players was 4.74 seconds (range, 4.33-5.55 seconds) compared with controls at 4.74 seconds (range, 4.34-5.38 seconds; P = .96). Jumping performance was also similar, with a mean vertical leap for ACL-reconstructed players of 33.35 inches (range, 23-43 inches) and broad jump of 113.9 inches (range, 96-136 inches) compared with respective values for the controls of 33.22 inches (range, 23.5-43.5 inches; P = .84) and 113.9 inches (range, 92-134 inches; P = .99). Agility and quickness testing measures also did not show a statistically significantly difference, with ACL-reconstructed players performing the shuttle drill in 4.37 seconds (range, 4.02-4.84 seconds) and the 3-cone drill in 7.16 seconds (range, 6.45-8.14 seconds), respectively, compared with respective times for the controls of 4.37 seconds (range, 3.96-5.00 seconds; P = .91) and 7.18 seconds (range, 6.64-8.24 seconds; P = .75). Conclusion: This study suggests that after ACL reconstruction, high-caliber athletes can achieve equivalent levels of perfor- mance with no statistically significant differences compared with matched controls. This information is unique when advising high-level athletes on athletic

  19. Combined anterolateral ligament and anatomic anterior cruciate ligament reconstruction of the knee.

    PubMed

    Smith, James O; Yasen, Sam K; Lord, Breck; Wilson, Adrian J

    2015-11-01

    Although anatomic anterior cruciate ligament (ACL) reconstruction is established for the surgical treatment of anterolateral knee instability, there remains a significant cohort of patients who continue to experience post-operative instability. Recent advances in our understanding of the anatomic, biomechanical and radiological characteristics of the native anterolateral ligament (ALL) of the knee have led to a resurgent interest in reconstruction of this structure as part of the management of knee instability. This technical note describes our readily reproducible combined minimally invasive technique to reconstruct both the ACL and ALL anatomically using autologous semitendinosus and gracilis grafts. This method of ALL reconstruction can be easily integrated with all-inside ACL reconstruction, requiring minimal additional operative time, equipment and expertise. Level of evidence V. PMID:26387120

  20. Effect of knee angle on quadriceps strength and activation after anterior cruciate ligament reconstruction

    PubMed Central

    Theuerkauf, Paul

    2015-01-01

    Quadriceps strength and activation deficits after anterior cruciate ligament (ACL) injury or surgery are typically evaluated at joint positions that are biomechanically advantageous to the quadriceps muscle. However, the effect of knee joint position and the associated changes in muscle length on strength and activation is currently unknown in this population. Here, we examined the effect of knee angle on quadriceps strength, activation, and electrically evoked torque in individuals with ACL reconstruction. Furthermore, we evaluated whether knee angle mediated the relationship between quadriceps weakness and functional performance after ACL reconstruction. Knee strength and activation were tested bilaterally at 90° and 45° of knee flexion in 11 subjects with ACL reconstruction using an interpolated triplet technique. The magnitude of electrically evoked torque at rest was used to quantify peripheral muscle contractile property changes, and the single-leg hop for distance test was used to evaluate functional performance. The results indicated that although quadriceps strength deficits were similar between knee angles, voluntary activation deficits were significantly higher in the reconstructed leg at 45° of knee flexion. On the contrary, the side-to-side evoked torque at rest ratio [i.e., (reconstructed/nonreconstructed) × 100] was significantly lower at 90° than at 45° of knee flexion. The association between quadriceps strength and functional performance was stronger at 45° of knee flexion. The results provide novel evidence that quadriceps activation is selectively affected at 45° of knee flexion and emphasize the importance of assessing quadriceps strength and activation at this position when feasible because it better captures activation deficits. PMID:25997949

  1. The Kinematic Control During the Backward Gait and Knee Proprioception: Insights from Lesions of the Anterior Cruciate Ligament

    PubMed Central

    Viggiano, Davide; Corona, Katia; Cerciello, Simone; Vasso, Michele; Schiavone-Panni, Alfredo

    2014-01-01

    An already existing large volume of work on kinematics documents a reduction of step length during unusual gaits, such as backward walking. This is mainly explained in terms of modifications of some biomechanical properties. In the present study, we propose that the proprioceptive information from the knee may be involved in this change of motor strategy. Specifically, we show that a non-automated condition such as backward walking can elicit different motor strategies in subjects with reduced proprioceptive feedback after anterior cruciate ligament lesion (ACL). For this purpose, the kinematic parameters during forward and backward walking in subjects with ACL deficit were compared to two control groups: a group with intact ACL and a group with surgically reconstructed ACL. The knee proprioception was tested measuring the threshold for detection of passive knee motion. Subjects were asked to walk on a level treadmill at five different velocities (1–5km/h) in forward and backward direction, thereby calculating the cadence and step length. Results showed that forward walking parameters were largely unaffected in subjects with ACL damage. However, they failed to reduce step length during backward walking, a correction that was normally observed in all control subjects and in subjects with normal proprioceptive feedback after ACL reconstruction. The main result of the present study is that knee proprioception is an important signal used by the brain to reduce step length during the backward gait. This can have a significant impact on clinical evaluation and rehabilitation. PMID:25114731

  2. Effectiveness of Knee Injury and Anterior Cruciate Ligament Tear Prevention Programs: A Meta-Analysis

    PubMed Central

    Collins, Jamie E.; Yang, Heidi Y.; Goczalk, Melissa G.; Katz, Jeffrey N.; Losina, Elena

    2015-01-01

    Objective Individuals frequently involved in jumping, pivoting or cutting are at increased risk of knee injury, including anterior cruciate ligament (ACL) tears. We sought to use meta-analytic techniques to establish whether neuromuscular and proprioceptive training is efficacious in preventing knee and ACL injury and to identify factors related to greater efficacy of such programs. Methods We performed a systematic literature search of studies published in English between 1996 and 2014. Intervention efficacy was ascertained from incidence rate ratios (IRRs) weighted by their precision (1/variance) using a random effects model. Separate analyses were performed for knee and ACL injury. We examined whether year of publication, study quality, or specific components of the intervention were associated with efficacy of the intervention in a meta-regression analysis. Results Twenty-four studies met the inclusion criteria and were used in the meta-analysis. The mean study sample was 1,093 subjects. Twenty studies reported data on knee injury in general terms and 16 on ACL injury. Maximum Jadad score was 3 (on a 0–5 scale). The summary incidence rate ratio was estimated at 0.731 (95% CI: 0.614, 0.871) for knee injury and 0.493 (95% CI: 0.285, 0.854) for ACL injury, indicating a protective effect of intervention. Meta-regression analysis did not identify specific intervention components associated with greater efficacy but established that later year of publication was associated with more conservative estimates of intervention efficacy. Conclusion The current meta-analysis provides evidence that neuromuscular and proprioceptive training reduces knee injury in general and ACL injury in particular. Later publication date was associated with higher quality studies and more conservative efficacy estimates. As study quality was generally low, these data suggest that higher quality studies should be implemented to confirm the preventive efficacy of such programs. PMID:26637173

  3. Addition of Autologous Mesenchymal Stem Cells to Whole Blood for Bio-Enhanced ACL Repair has No Benefit in the Porcine Model

    PubMed Central

    Proffen, Benedikt L.; Vavken, Patrick; Haslauer, Carla M.; Fleming, Braden C.; Harris, Chad E.; Machan, Jason T.; Murray, Martha M.

    2015-01-01

    Background Co-culture of mesenchymal stem cells (MSCs) from the retropatellar fat pad and peripheral blood has been shown to stimulate anterior cruciate ligament (ACL) fibroblast proliferation and collagen production in vitro. Current techniques of bio-enhanced ACL repair in animal studies involve adding a biologic scaffold, in this case an extracellular matrix based scaffold saturated with autologous whole blood, to a simple suture repair of the ligament. Whether the enrichment of whole blood with MSCs would further improve the in vivo results of bio-enhanced ACL repair was investigated. Hypothesis/Purpose The hypothesis was that the addition of MSCs derived from adipose tissue or peripheral blood to the blood-extracellular matrix composite, which is used in bio-enhanced ACL repair to stimulate healing, would improve the biomechanical properties of a bio-enhanced ACL repair after 15 weeks of healing. Study Design Controlled laboratory study. Methods Twenty-four adolescent Yucatan mini-pigs underwent ACL transection followed by: 1) bio-enhanced ACL repair, 2) bio-enhanced ACL repair with the addition of autologous adipose-derived MSCs and 3) bio-enhanced ACL repair with the addition of autologous peripheral blood derived MSCs. After fifteen weeks of healing, structural properties of the ACL (yield & failure load, linear stiffness) were measured. Cell and vascular density were measured in the repaired ACL via histology, and its tissue structure was qualitatively evaluated using the Advanced Ligament Maturity Index. Results After fifteen weeks of healing, there were no significant improvements in the biomechanical or histological properties with the addition of adipose-derived MSCs. The only significant change with the addition of peripheral blood MSCs was an increase in knee anteroposterior (AP) laxity when measured at 30 degrees of flexion. Conclusions These findings suggest that the addition of adipose or peripheral blood MSCs to whole blood prior to saturation of

  4. Single-Bundle Versus Double-Bundle Acl Reconstructions in Isolation and in Conjunction with Extra-Articular Iliotibial Band Tenodesis

    PubMed Central

    Butler, Paul D.; Mellecker, Chloe J.; Rudert, M. James; Albright, John P.

    2013-01-01

    Background Intra-articular anterior cruciate ligament (ACL) reconstruction has been the primary treatment option for isolated ACL injuries for many years. An anatomic double-bundle reconstruction has been devised in an effort to improve rotational control. The role of the extra-articular iliotibial band tenodesis in ACL injuries has evolved from primary treatment, to an adjuvant secondary procedure, to being used more selectively in revision ACL reconstructions. Hypotheses: 1) Single-bundle and doublebundle intra-articular ACL reconstructions will both restore pre-injury laxity measurements in an isolated ACL injury cadaver model. 2) The deep iliotibial band structures contribute to rotational control and in a dual ACL + ITB injury cadaver model, ACL reconstruction alone cannot restore rotational control. Study Design Controlled Laboratory Design Methods 17 fresh frozen cadavers received intra-articular reconstructions, seven single-bundle and ten double-bundle; laxity was measured with the ACL intact/ITB intact, ACL reconstructed/ITB intact, after cutting the ITB, and after an ITB tenodesis procedure; laxity measurements of anterior tibial translation(ATT) and internal rotation(IR) were measured following applications of an anterior shear force, an internal torque and a coupled anterior shear force-internal torque at 30 and 90 degrees of flexion. Results Single-bundle and double-bundle ACL reconstructions both restored IR to a native knee state under isolated internal torques and under coupled forces. Both reconstruction techniques also re-established anterior tibial translation to at least the pre-ACL injury level, with over-constraint in the double-bundle subgroup [5.00 (+2.11) to 3.50(+1.18), p-value 0.026] under coupled loads at 30 degrees of flexion. With the individual ACL reconstructions held constant, under coupled forces mean IR increased in the single-bundle subgroup [13.7(+1.1) to 17.6(+1.2), p-value 0.004] and the double-bundle subgroup [9.5(+1.0) to

  5. Acute Vs Delayed ACL Reconstruction. Early Differences and Preliminary Two Year Results

    PubMed Central

    Eriksson, Karl; Barenius, Björn

    2016-01-01

    Objectives: Historically acute ACL reconstruction has been avoided due to reports of early rehabilitation problems with stiffness. Are these reports still valid today with modern arthroscopic techniques? Methods: 70 patients with a high recreational activity level (Tegner ≥6) who presented with a acute ACL injury were randomized to an acute reconstruction within 8 days from the injury or delayed reconstruction after 6-10 weeks. Four surgeons performed the ACL reconstructions with quadrupled semitendinosus tendon grafts and endobutton and metallic interference screw fixation. The rehabilitation training was performed at the same physiotherapy center for all patients. The follow up at 6 and 24 months included ROM, Lachman, Rolimeter, pivot shift, one leg hop, IKDC, KOOS, Lysholm and Tegner activity level. Results: There were no differences between the groups in ROM, IKDC, activity level or laxity at 6 months. Four patients had a combined extension and flexion deficit of more than 15 degrees, two from each group. In the acute group 79% had an objective IKDC grade A or B compared with 73% in the delayed group. The one leg hop index above 90% was found in 50% in the acute group and 24% in the delayed group (p=0.04). Functional data for the 2-year follow up are not available at the time of abstract writing. The median activity level according to Tegner was restored to pre-injury levels in both groups after one year, and was stationary at 2 years. The visual analogue scale (VAS) response to the question “How is your knee working on a scale from 0-100? (100 = best)” revealed 81 in the acute and 71 in the delayed group (p=0.1). To the question “How does your knee affect your activity level on a scale from 0-100? (100 = no affection)” the mean score was 75 in the acute group and 67 in the delayed group (p=0.3). At one and two years the KOOS was statistically similar between the groups but with slightly higher subscale “Sport and recreation” scores, 85 in the

  6. Femoral tunnel malposition in ACL revision reconstruction.

    PubMed

    Morgan, Joseph A; Dahm, Diane; Levy, Bruce; Stuart, Michael J

    2012-11-01

    The Multicenter Anterior Cruciate Ligament (ACL) Revision Study (MARS) group was formed to study a large cohort of revision ACL reconstruction patients. The purpose of this subset analysis study of the MARS database is to describe specific details of femoral tunnel malposition and subsequent management strategies that surgeons chose in the revision setting. The design of this study is a case series. The multicenter MARS database is compiled from a questionnaire regarding 460 ACL reconstruction revision cases returned by 87 surgeons. This subset analysis described technical aspects and operative findings in specifically those cases in which femoral tunnel malposition was cited as the cause of primary ACL reconstruction failure. Of the 460 revisions included for study, 276 (60%) cases cited a specific "technical cause of failure." Femoral tunnel malposition was cited in 219 (47.6%) of 460 cases. Femoral tunnel malposition was cited as the only cause of failure in 117 cases (25.4%). Surgeons judged the femoral tunnel too vertical in 42 cases (35.9%), too anterior in 35 cases (29.9%), and too vertical and anterior in 31 cases (26.5%). Revision reconstruction involved the drilling of an entirely new femoral tunnel in 91 cases (82.1%). For primary reconstruction, autograft tissue was used in 82 cases (70.1%). For revision reconstruction, autograft tissue was used in 61 cases (52.1%) and allograft tissue in 56 cases (47.9%). Femoral tunnel malposition in primary ACL reconstruction was the most commonly cited reason for graft failure in this cohort. Graft selection is widely variable among surgeons. PMID:23150344

  7. Femoral Tunnel Malposition in ACL Revision Reconstruction

    PubMed Central

    Morgan, Joseph A.; Dahm, Diane; Levy, Bruce; Stuart, Michael J.

    2013-01-01

    The Multicenter Anterior Cruciate Ligament (ACL) Revision Study (MARS) group was formed to study a large cohort of revision ACL reconstruction patients. The purpose of this subset analysis study of the MARS database is to describe specific details of femoral tunnel malposition and subsequent management strategies that surgeons chose in the revision setting. The design of this study is a case series. The multicenter MARS database is compiled from a questionnaire regarding 460 ACL reconstruction revision cases returned by 87 surgeons. This subset analysis described technical aspects and operative findings in specifically those cases in which femoral tunnel malposition was cited as the cause of primary ACL reconstruction failure. Of the 460 revisions included for study, 276 (60%) cases cited a specific “technical cause of failure.” Femoral tunnel malposition was cited in 219 (47.6%) of 460 cases. Femoral tunnel malposition was cited as the only cause of failure in 117 cases (25.4%). Surgeons judged the femoral tunnel too vertical in 42 cases (35.9%), too anterior in 35 cases (29.9%), and too vertical and anterior in 31 cases (26.5%). Revision reconstruction involved the drilling of an entirely new femoral tunnel in 91 cases (82.1%). For primary reconstruction, autograft tissue was used in 82 cases (70.1%). For revision reconstruction, autograft tissue was used in 61 cases (52.1%) and allograft tissue in 56 cases (47.9%). Femoral tunnel malposition in primary ACL reconstruction was the most commonly cited reason for graft failure in this cohort. Graft selection is widely variable among surgeons. PMID:23150344

  8. Single-Bundle Anterior Cruciate Ligament Reconstruction with Semitendinosus Tendon Using the PINN-ACL CrossPin System: Minimum 4-Year Follow-up

    PubMed Central

    Baek, Seung-Gil; Lee, Byoung-Joo; Lee, Chang-Hwa

    2015-01-01

    Purpose This study evaluated mid-term results of anterior cruciate ligament (ACL) reconstruction using the PINN-ACL CrossPin system that allowed for short graft fixation. Materials and Methods Forty-three patients underwent single-bundle ACL reconstruction with a 4-strand semitendinosus tendon graft using the PINN-ACL CrossPin system. Femoral fixation was done using the PINN-ACL CrossPin system, and the tibial side was fixed with post-tie and a bioabsorbable interference screw. The mean follow-up period was 50 months. Evaluation was done using the Lachman test, pivot-shift test, International Knee Documentation Committee (IKDC) score and grade. Anterior displacement was assessed. Results There was improvement in the Lachman test and pivot-shift test at final follow-up, form grade II (n=40) or III (n=3) to grade I (n=3) or 0 (n=40) and from grade I (n=20) or II (n=10) to grade I (n=8) or 0 (n=22), respectively. The mean IKDC score was 88.7, and grade A and B were 93.0% at final follow-up. Side-to-side difference was improved from 6.7 mm to 2.1 mm at final follow-up. Complications occurred in 3 patients, a re-ruptured due to trauma at 2 years after surgery and a deep infection and a superficial infection. Conclusions The mid-term follow-up results of ACL reconstruction with the PINN-ACL CrossPin system were satisfactory. The PINN-ACL CrossPin can be considered as a useful instrument for short graft fixation. PMID:25750893

  9. Knee arthroscopy - series (image)

    MedlinePlus

    ... knee problems such as: a torn knee disc (meniscus) a damaged knee bone (patella) a damaged ligament ... surgeon can see the ligaments, the knee disc (meniscus), the knee bone (patella), the lining of the ...

  10. EVALUATION OF THE RESULTS OF ARTHROSCOPIC ACL RECONSTRUCTION WITH AUTOGENOUS FLEXOR TENDONS

    PubMed Central

    Almeida, Alexandre; Valin, Múrcio Rangel; Ferreira, Ramon; Roveda, Gilberto; de Almeida, Nayvaldo Couto; Agostini, Ana Paula

    2015-01-01

    Objective: To evaluate the results from reconstruction of the anterior cruciate ligament (ACL) using with flexor tendon autografts from the thigh, with analysis on data relating to sex, body mass index (BMI) and associations with lower limb fracture. Methods: A group of 265 patients who underwent knee arthroscopy for the purposes of ACL reconstruction using an ipsilateral graft from the flexor tendon of the thigh between July 6, 2000, and November 19, 2007, were evaluated. Results: One hundred and seventy-six patients were evaluated over a mean period of 34.95 ± 18.8 months (median: 31 months) (IQR: 20-48 months). The minimum evaluation period was 12 months and the maximum was 87 months. One hundred and thirty-eight patients (78.4%) had excellent results, 22 (12.5%) had good results, eight (4.5%) had fair results and eight (4.5%) had poor results. Higher incidence of good and excellent results for the following categories was not considered to be significant: males (p = 0.128), patients with BMI < 25 (p = 0.848), or patients with ACL injuries unrelated to an initial traumatic episode of lower-limb fracture (p = 0.656). Conclusion: The ACL reconstruction technique using tendon autografts from the thigh showed good and excellent results for 91.4% of the sample. Male patients seemed to present a greater tendency towards good and excellent results. No statistically significant difference was found when the results were analyzed in relation to BMI or associations with initial traumatic fracture episodes in the lower limbs. PMID:27022571

  11. Decreased Knee Joint Loading Associated With Early Knee Osteoarthritis After Anterior Cruciate Ligament Injury

    PubMed Central

    Wellsandt, Elizabeth; Gardinier, Emily S.; Manal, Kurt; Axe, Michael J.; Buchanan, Thomas S.; Snyder-Mackler, Lynn

    2015-01-01

    Background Anterior cruciate ligament (ACL) injury predisposes individuals to early-onset knee joint osteoarthritis (OA). Abnormal joint loading is apparent after ACL injury and reconstruction. The relationship between altered joint biomechanics and the development of knee OA is unknown. Hypothesis Altered knee joint kinetics and medial compartment contact forces initially after injury and reconstruction are associated with radiographic knee OA 5 years after reconstruction. Study Design Case-control study; Level of evidence, 3. Methods Individuals with acute, unilateral ACL injury completed gait analysis before (baseline) and after (posttraining) preoperative rehabilitation and at 6 months, 1 year, and 2 years after reconstruction. Surface electromyographic and knee biomechanical data served as inputs to an electromyographically driven musculoskeletal model to estimate knee joint contact forces. Patients completed radiographic testing 5 years after reconstruction. Differences in knee joint kinetics and contact forces were compared between patients with and those without radiographic knee OA. Results Patients with OA walked with greater frontal plane interlimb differences than those without OA (nonOA) at baseline (peak knee adduction moment difference: 0.00 ± 0.08 N·m/kg·m [nonOA] vs −0.15 ± 0.09 N·m/kg·m [OA], P = .014; peak knee adduction moment impulse difference: −0.001 ± 0.032 N·m·s/kg·m [nonOA] vs −0.048 ± 0.031 N·m·s/kg·m [OA], P = .042). The involved limb knee adduction moment impulse of the group with osteoarthritis was also lower than that of the group without osteoarthritis at baseline (0.087 ± 0.023 N·m·s/kg·m [nonOA] vs 0.049 ± 0.018 N·m·s/kg·m [OA], P = .023). Significant group differences were absent at posttraining but reemerged 6 months after reconstruction (peak knee adduction moment difference: 0.02 ± 0.04 N·m/kg·m [nonOA] vs −0.06 ± 0.11 N·m/kg·m [OA], P = .043). In addition, the OA group walked with lower peak

  12. A Novel Device to Apply Controlled Flexion and Extension to the Rat Knee Following Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Eng, Mark Stasiak M.; Wiznia, Dan; Alzoobae, Saif; Ciccotti, Michael; Imhauser, Carl; Voigt, Clifford; Torzilli, Peter; Deng, Xenghua; Rodeo, Scott

    2013-01-01

    We designed and validated a novel device for applying flexion-extension cycles to a rat knee in an in-vivo model of anterior cruciate ligament reconstruction (ACL-R). Our device is intended to simulate rehabilitation motion and exercise post ACL-R to optimize physical rehabilitation treatments for the improved healing of tendon graft ligament reconstructions. The device was validated for repeatability of the knee kinematic motion by measuring the force versus angular rotation response from repeated trials using cadaver rats. The average maximum force required for rotating an ACL reconstructed rat knee through 100 degrees of flexion-extension was 0.4 N with 95 % variability for all trials within ±0.1 N PMID:22667683

  13. Acute ACL Surgery Decreases First Year Socio Economic Costs Compared to Delayed Reconstruction

    PubMed Central

    Eriksson, Karl; von Essen, Christoffer; Barenius, Björn

    2016-01-01

    Objectives: Clinical practice has been to avoid acute ACL reconstruction due to the risk of complications, especially arthrofibrosis. Thus, a general rule has been to wait with reconstruction until he knee is “calm” which usually means 4-8 weeks following injury. Furthermore there is often also a prolonged waiting time due to operating space and other logistic factors. Since most of the patients undergoing ACL reconstruction are of working age, there is a potentially large socio-economic loss due to the fact that many of these patients are unable to work from the time of injury to the time of reconstruction. The aim of this study was to assess and compare the total number of sick leave days caused by the knee injury from the day of injury and over the first year between sub acute and delayed reconstruction. Methods: 70 patients with high recreational activity level, Tegner level of 6 or more, who presented with an acute ACL injury were randomized to acute reconstruction within 8 days from the injury or delayed reconstruction 6-10 weeks post injury. Four surgeons performed the ACL reconstructions with quadrupled semitendinosus tendon grafts. Patients were assessed at 6,12 and 24 months and these follow ups included Biodex strength test, Lachman, Rolimeter, pivot shift, one leg hop, IKDC, KOOS, Lysholm and Tegner activity level. With data from the Swedish Social Insurance Agency (Försäkringskassan) information about the number of sick leave days from the day of the knee injury and over the following twelve months was collected. The data was recalled based on diagnostic numbers related to the specific knee-injury and compared between the two groups. Results: Seventy percent of the patients were males, mean age at the time of inclusion was 27 years (18 -41) and the pre-injury median Tegner level was 9 (5-10), with no differences between the groups. 15/70 patients were students without registered compensation for sick leave, 5 in the acute and 10 in the delayed

  14. Anterior cruciate ligament- specialized post-operative return-to-sports (ACL-SPORTS) training: a randomized control trial

    PubMed Central

    2013-01-01

    Background Anterior cruciate ligament reconstruction (ACLR) is standard practice for athletes that wish to return to high-level activities; however functional outcomes after ACLR are poor. Quadriceps strength weakness, abnormal movement patterns and below normal knee function is reported in the months and years after ACLR. Second ACL injuries are common with even worse outcomes than primary ACLR. Modifiable limb-to-limb asymmetries have been identified in individuals who re-injure after primary ACLR, suggesting a neuromuscular training program is needed to improve post-operative outcomes. Pre-operative perturbation training, a neuromuscular training program, has been successful at improving limb symmetry prior to surgery, though benefits are not lasting after surgery. Implementing perturbation training after surgery may be successful in addressing post-operative deficits that contribute to poor functional outcomes and second ACL injury risk. Methods/Design 80 athletes that have undergone a unilateral ACLR and wish to return to level 1 or 2 activities will be recruited for this study and randomized to one of two treatment groups. A standard care group will receive prevention exercises, quadriceps strengthening and agility exercises, while the perturbation group will receive the same exercise program with the addition of perturbation training. The primary outcomes measures will include gait biomechanics, clinical and functional measures, and knee joint loading. Return to sport rates, return to pre-injury level of activity rates, and second injury rates will be secondary measures. Discussion The results of this ACL-Specialized Post-Operative Return To Sports (ACL-SPORTS) Training program will help clinicians to better determine an effective post-operative treatment program that will improve modifiable impairments that influence outcomes after ACLR. Trial registration Randomized Control Trial NIH 5R01AR048212-07. ClinicalTrials.gov: NCT01773317 PMID:23522373

  15. Common injuries in athletes' knee: experience of a specialized center

    PubMed Central

    Nicolini, Alexandre Pedro; de Carvalho, Rogério Teixeira; Matsuda, Marcelo Mitsuro; Sayum, Jorge; Cohen, Moisés

    2014-01-01

    OBJECTIVE: The present cross-sectional study aims to identify the most common knee injuries in athletes cared at a Specialized Outpatient Clinics. METHOD: Analysis of patients cared at the Knee Outpatient Clinics of a Sports Trauma Center, divided by gender, age and diagnosed injury. RESULTS: Initially 440 patients were divided into 33 types of sports; after excluding the less statistically significant practices, nine sports remained. The most frequently performed sports were football with almost 50% of total patients presenting anterior cruciate ligament (ACL) injury, and road runs with great frequency of meniscal injury. There was no correlation of the disorder with the type of sports performed but a correlation was found with patient's age/gender. CONCLUSION: The complete ACL rupture was the most common injury found in football, basketball and volleyball players, followed by meniscal injury in street runners. Level of Evidence IV, Study Transversal. PMID:25061417

  16. Non-contact ACL Injuries: Mechanisms and Risk Factors

    PubMed Central

    Boden, Barry P.; Sheehan, Frances T.; Torg, Joseph S.; Hewett, Timothy E.

    2013-01-01

    Significant advances have recently been made in understanding the mechanisms involved in noncontact anterior cruciate ligament (ACL) injury. Most ACL injuries involve minimal to no contact. Female athletes sustain a two- to eightfold greater rate of injury than do their male counterparts. Recent videotape analyses demonstrate significant differences in average leg and trunk positions during injury compared with control subjects. These findings as well as those of cadaveric and MRI studies indicate that axial compressive forces are a critical component in noncontact ACL injury. A complete understanding of the forces and risk factors associated with noncontact ACL injury should lead to the development of improved preventive strategiess for this devastating injury. PMID:20810933

  17. Fetal ACL Fibroblasts Exhibit Enhanced Cellular Properties Compared with Adults

    PubMed Central

    Stalling, Simone S.

    2008-01-01

    Fetal tendons and skin heal regeneratively without scar formation. Cells isolated from these fetal tissues exhibit enhanced cellular migration and collagen production in comparison to cells from adult tissue. We determined whether fetal and adult fibroblasts isolated from the anterior cruciate ligament (ACL), a tissue that does not heal regeneratively, exhibit differences in cell migration rates and collagen elaboration. An in vitro migration assay showed fetal ACL fibroblasts migrated twice as fast as adult ACL fibroblasts at a rate of 38.90 ± 7.69 μm per hour compared with 18.88 ± 4.18 μm per hour, respectively. Quantification of Type I collagen elaboration by enzyme-linked immunosorbent assay showed fetal ACL fibroblasts produced four times the amount of Type I collagen compared with adult ACL fibroblasts after 7 days in culture. We observed no differences in Type III collagen with time for adult or fetal ACL fibroblasts. Our findings indicate fetal ACL fibroblasts are intrinsically different from adult ACL fibroblasts, suggesting the healing potential of the ACL may be age-dependent. PMID:18648900

  18. Unique Anatomic Feature of the Posterior Cruciate Ligament in Knees Associated With Osteochondritis Dissecans

    PubMed Central

    Ishikawa, Masakazu; Adachi, Nobuo; Yoshikawa, Masahiro; Nakamae, Atsuo; Nakasa, Tomoyuki; Ikuta, Yasunari; Hayashi, Seiju; Deie, Masataka; Ochi, Mitsuo

    2016-01-01

    Background: Osteochondritis dissecans (OCD) of the knee is a disorder in juveniles and young adults; however, its etiology still remains unclear. For OCD at the medial femoral condyle (MFC), it is sometimes observed that the lesion has a connection with fibers of the posterior cruciate ligament (PCL). Although this could be important information related to the etiology of MFC OCD, there is no report examining an association between the MFC OCD and the PCL anatomy. Purpose: To investigate the anatomic features of knees associated with MFC OCD, focusing especially on the femoral attachment of the PCL, and to compare them with knees associated with lateral femoral condyle (LFC) OCD and non-OCD lesions. Study Design: Case-control study; Level of evidence, 3. Methods: We retrospectively reviewed 39 patients (46 knees) with OCD lesions who had undergone surgical treatment. Using magnetic resonance imaging (MRI) scans, the PCL attachment at the lateral wall of the MFC was measured on the coronal sections, and the knee flexion angle was also measured on the sagittal sections. As with non-OCD knees, we reviewed and analyzed 25 knees with anterior cruciate ligament (ACL) injuries and 16 knees with meniscal injuries. Results: MRIs revealed that the femoral PCL footprint was located in a significantly more distal position in the patients with MFC OCD compared with patients with LFC OCD and ACL and meniscal injuries. There was no significant difference in knee flexion angle among the 4 groups. Conclusion: The PCL in patients with MFC OCD attached more distally at the lateral aspect of the MFC compared with knees with LFC OCD and ACL and meniscal injuries. PMID:27294170

  19. Avoiding Complications and Technical Variability During Arthroscopically Assisted Transtibial ACL Reconstructions by Using a C-Arm With Image Intensifier

    PubMed Central

    Trentacosta, Natasha; Fillar, Allison Liefeld; Liefeld, Cynthia Pierce; Hossack, Michael D.; Levy, I. Martin

    2014-01-01

    Background: Surgical reconstruction of the anterior cruciate ligament (ACL) can be complicated by incorrect and variable tunnel placement, graft tunnel mismatch, cortical breaches, and inadequate fixation due to screw divergence. This is the first report describing the use of a C-arm with image intensifier employed for the sole purpose of eliminating those complications during transtibial ACL reconstruction. Purpose: To determine if the use of a C-arm with image intensifier during arthroscopically assisted transtibial ACL reconstruction (IIAA-TACLR) eliminated common complications associated with bone–patellar tendon–bone ACL reconstruction, including screw divergence, cortical breaches, graft-tunnel mismatch, and improper positioning of the femoral and tibial tunnels. Study Design: Case series; Level of evidence, 4. Methods: A total of 110 consecutive patients (112 reconstructed knees) underwent identical IIAA-TACLR using a bone–patellar tendon–bone autograft performed by a single surgeon. Intra- and postoperative radiographic images and operative reports were evaluated for each patient looking for evidence of cortical breeching and screw divergence. Precision of femoral tunnel placement was evaluated using a sector map modified from Bernard et al. Graft recession distance and tibial α angles were recorded. Results: There were no femoral or tibial cortical breaches noted intraoperatively or on postoperative images. There were no instances of loss of fixation screw major thread engagement. There were no instances of graft-tunnel mismatch. The positions of the femoral tunnels were accurate and precise, falling into the desired sector of our location map (sector 1). Tibial α angles and graft recession distances varied widely. Conclusion: The use of the C-arm with image intensifier enabled accurate and precise tunnel placement and completely eliminated cortical breach, graft-tunnel mismatch, and screw divergence during IIAA-TACLR by allowing incremental

  20. Knee medial collateral ligament and posteromedial corner anatomic repair with internal bracing.

    PubMed

    Lubowitz, James H; MacKay, Gordon; Gilmer, Brian

    2014-08-01

    An internal brace is a ligament repair bridging concept using braided ultrahigh-molecular-weight polyethylene/polyester suture tape and knotless bone anchors to reinforce ligament strength as a secondary stabilizer after repair and return to sports, which may help resist injury recurrence. An internal brace may provide augmentation during knee medial and posteromedial corner anatomic repair. In patients with combined, chronic, symptomatic anterior cruciate ligament (ACL)-posteromedial corner laxity, combined ACL reconstruction with posteromedial corner reconstruction is indicated. Our ACL technique was previously published with video illustration in Arthroscopy and Arthroscopy Techniques. The purpose of this article is to describe, with video illustration, knee posteromedial corner reconstruction using anatomic repair with internal brace augmentation. PMID:25276610

  1. Comparative adaptations of lower limb biomechanics during unilateral and bilateral landings after different neuromuscular-based ACL injury prevention protocols.

    PubMed

    Brown, Tyler N; Palmieri-Smith, Riann M; McLean, Scott G

    2014-10-01

    Potentially valuable anterior cruciate ligament (ACL) injury prevention strategies are lengthy, limiting training success. Shorter protocols that achieve beneficial biomechanical adaptations may improve training effectiveness. This study examined whether core stability/balance and plyometric training can modify female landing biomechanics compared with the standard neuromuscular and no training models. Forty-three females had lower limb biomechanics analyzed during unilateral and bilateral landings immediately before and after a 6-week neuromuscular or no training programs. Sagittal and frontal plane hip and knee kinematics and kinetics were submitted to 3-way repeated-measures analyses of variance to test for the main and interaction effects of training group, landing type, and testing time. Greater peak knee flexion was evident in the standard neuromuscular group following training, during both bilateral (p = 0.027) and unilateral landings (p = 0.076 and d = 0.633). The plyometric group demonstrated reduced hip adduction (p = 0.010) and greater knee flexion (p = 0.065 and d = 0.564) during bilateral landings following training. The control group had significant reduction in peak stance knee abduction moment (p = 0.003) posttraining as compared with pretraining. The current outcomes suggest that significant biomechanical changes are possible by an isolated plyometric training component. The benefits, however, may not be evident across all landing types, seemingly limited to simplistic, bilateral landings. Integrated training protocols may still be the most effective training model, currently improving knee flexion posture during both bilateral and unilateral landings following training. Future prevention efforts should implement integrated training protocols that include plyometric exercises to reduce ACL injury risk of female athletes. PMID:24714537

  2. Characterization of thigh and shank segment angular velocity during jump landing tasks commonly used to evaluate risk for ACL injury.

    PubMed

    Dowling, Ariel V; Favre, Julien; Andriacchi, Thomas P

    2012-09-01

    The dynamic movements associated with anterior cruciate ligament (ACL) injury during jump landing suggest that limb segment angular velocity can provide important information for understanding the conditions that lead to an injury. Angular velocity measures could provide a quick and simple method of assessing injury risk without the constraints of a laboratory. The objective of this study was to assess the inter-subject variations and the sensitivity of the thigh and shank segment angular velocity in order to determine if these measures could be used to characterize jump landing mechanisms. Additionally, this study tested the correlation between angular velocity and the knee abduction moment. Thirty-six healthy participants (18 male) performed drop jumps with bilateral and unilateral landing. Thigh and shank angular velocities were measured by a wearable inertial-based system, and external knee moments were measured using a marker-based system. Discrete parameters were extracted from the data and compared between systems. For both jumping tasks, the angular velocity curves were well defined movement patterns with high inter-subject similarity in the sagittal plane and moderate to good similarity in the coronal and transverse planes. The angular velocity parameters were also able to detect differences between the two jumping tasks that were consistent across subjects. Furthermore, the coronal angular velocities were significantly correlated with the knee abduction moment (R of 0.28-0.51), which is a strong indicator of ACL injury risk. This study suggested that the thigh and shank angular velocities, which describe the angular dynamics of the movement, should be considered in future studies about ACL injury mechanisms. PMID:22938373

  3. Return to sport after ACL reconstruction.

    PubMed

    Harris, Joshua D; Abrams, Geoffrey D; Bach, Bernard R; Williams, Donna; Heidloff, Dave; Bush-Joseph, Charles A; Verma, Nikhil N; Forsythe, Brian; Cole, Brian J

    2014-02-01

    Objective guidelines permitting safe return to sport following anterior cruciate ligament (ACL) reconstruction are infrequently used. The purpose of this study was to determine the published return to sport guidelines following ACL reconstruction in Level I randomized controlled trials. A systematic review was performed using Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Level I randomized controlled trials were included if they reported a minimum 2-year follow-up after ACL reconstruction and return to sport criteria. Outcomes analyzed were the timing of initiation of return to sport, follow-up duration, and use of quantitative/qualitative criteria to determine return to sport. Forty-nine studies were included (N=4178; 68% male; mean patient age, 27.5±3.2 years; mean follow-up, 3.0±1.9 years; mean time from injury to reconstruction, 379±321 days). Ninety-six percent of reconstructions used autograft and 87% were single-bundle reconstructions. Lysholm score, single-leg hop, isokinetic strength, and KT-1000 or KT-2000 arthrometer (MEDmetric, San Diego, California) testing were performed in 67%, 31%, 31%, and 82% of studies, respectively. Only 5 studies reported whether patients were able to successfully return to sport. Ninety percent and 65% of studies failed to use objective criteria or any criteria, respectively, to permit return to sport. Description of permission/allowance to return to sport was highly variable and poor. Twenty-four percent of studies failed to report when patients were allowed return to sport without restrictions. Overall, 39%, 45%, and 51% of studies permitted running at 3 months, return to cutting/pivoting sports at 6 months, and return to sport without restrictions at 6 months, respectively. Further research into validated return to sport guidelines is necessary to fill the existing void in contemporary literature and to guide clinical practice. PMID:24679194

  4. Incidence of Second ACL Injuries 2 Years After Primary ACL Reconstruction and Return to Sport

    PubMed Central

    Paterno, Mark V.; Rauh, Mitchell J.; Schmitt, Laura C.; Ford, Kevin R.; Hewett, Timothy E.

    2014-01-01

    Background The incidence of second anterior cruciate ligament (ACL) injuries in the first 12 months after ACL reconstruction (ACLR) and return to sport (RTS) in a young, active population has been reported to be 15 times greater than that in a previously uninjured cohort. There are no reported estimates of whether this high relative rate of injury continues beyond the first year after RTS and ACLR. Hypothesis The incidence rate of a subsequent ACL injury in the 2 years after ACLR and RTS would be less than the incidence rate reported within the first 12 months after RTS but greater than the ACL injury incidence rate in an uninjured cohort of young athletes. Study Design Cohort study; Level of evidence, 2. Methods Seventy-eight patients (mean age, 17.1 ± 3.1 years) who underwent ACLR and were ready to return to a pivoting/ cutting sport and 47 controls (mean age, 17.2 ± 2.6 years) who also participated in pivoting/cutting sports were prospectively enrolled. Each participant was followed for injury and athlete exposure (AE) data for a 24-month period after RTS. Twenty-three ACLR and 4 control participants suffered an ACL injury during this time. Incidence rate ratios (IRRs) were calculated to compare the rates (per 1000 AEs) of ACL injury in athletes in the ACLR and control groups. For the ACLR group, similar comparisons were conducted for side of injury by sex. Results The overall incidence rate of a second ACL injury within 24 months after ACLR and RTS (1.39/1000 AEs) was nearly 6 times greater (IRR, 5.71; 95% CI, 2.0–22.7; P = .0003) than that in healthy control participants (0.24/1000 AEs). The rate of injury within 24 months of RTS for female athletes in the ACLR group was almost 5 times greater (IRR, 4.51; 95% CI, 1.5–18.2; P = .0004) than that for female controls. Although only a trend was observed, female patients within the ACLR group were twice as likely (IRR, 2.43; 95% CI, 0.8–8.6) to suffer a contralateral injury (1.13/1000 AEs) than an

  5. Transphyseal ACL Reconstruction in Skeletally Immature Patients

    PubMed Central

    Cruz, Aristides I.; Lakomkin, Nikita; Fabricant, Peter D.; Lawrence, J. Todd R.

    2016-01-01

    Background: Most studies examining the safety and efficacy of transphyseal anterior cruciate ligament (ACL) reconstruction for skeletally immature patients utilize transtibial drilling. Independent femoral tunnel drilling may impart a different pattern of distal femoral physeal involvement. Purpose: To radiographically assess differences in distal femoral physeal disruption between transtibial and independent femoral tunnel drilling. We hypothesized that more oblique tunnels associated with independent drilling involve a significantly larger area of physeal disruption compared with vertically oriented tunnels. Study Design: Cross-sectional study; Level of evidence, 3. Methods: We analyzed skeletally immature patients aged between 10 and 15 years who underwent transphyseal ACL reconstruction utilizing an independent femoral tunnel drilling technique between January 1, 2008, and March 31, 2011. These patients were matched with a transtibial technique cohort based on age and sex. Radiographic measurements were recorded from preoperative magnetic resonance imaging and postoperative radiographs. Results: Ten patients in each group were analyzed. There were significant differences between independent drilling and transtibial drilling cohorts in the estimated area of physeal disruption (1.64 vs 0.74 cm2; P < .001), femoral tunnel angles (32.1° vs 72.8°; P < .001), and medial/lateral location of the femoral tunnel (24.2 vs 36.1 mm from lateral cortex; P = .001), respectively. There was a significant inverse correlation between femoral tunnel angle and estimated area of distal femoral physeal disruption (r = –0.8255, P = .003). Conclusion: Femoral tunnels created with an independent tunnel drilling technique disrupt a larger area of the distal femoral physis and create more eccentric tunnels compared with a transtibial technique. Clinical Relevance: As most studies noting the safety of transphyseal ACL reconstruction have utilized a central, vertical femoral tunnel

  6. Runner's Knee

    MedlinePlus

    ... Over the summer he bought a pair of running shoes and took up jogging. He started with ... bending the knee — when walking, kneeling, squatting, or running, for example. Walking or running downhill or even ...

  7. Knee Injuries and Disorders

    MedlinePlus

    Your knee joint is made up of bone, cartilage, ligaments and fluid. Muscles and tendons help the knee joint move. When any of these structures is hurt or diseased, you have knee problems. Knee problems can cause pain and difficulty ...

  8. Knee Dislocations

    PubMed Central

    Schenck, Robert C.; Richter, Dustin L.; Wascher, Daniel C.

    2014-01-01

    Background: Traumatic knee dislocation is becoming more prevalent because of improved recognition and increased exposure to high-energy trauma, but long-term results are lacking. Purpose: To present 2 cases with minimum 20-year follow-up and a review of the literature to illustrate some of the fundamental principles in the management of the dislocated knee. Study Design: Review and case reports. Methods: Two patients with knee dislocations who underwent multiligamentous knee reconstruction were reviewed, with a minimum 20-year follow-up. These patients were brought back for a clinical evaluation using both subjective and objective measures. Subjective measures include the following scales: Lysholm, Tegner activity, visual analog scale (VAS), Short Form–36 (SF-36), International Knee Documentation Committee (IKDC), and a psychosocial questionnaire. Objective measures included ligamentous examination, radiographic evaluation (including Telos stress radiographs), and physical therapy assessment of function and stability. Results: The mean follow-up was 22 years. One patient had a vascular injury requiring repair prior to ligament reconstruction. The average assessment scores were as follows: SF-36 physical health, 52; SF-36 mental health, 59; Lysholm, 92; IKDC, 86.5; VAS involved, 10.5 mm; and VAS uninvolved, 2.5 mm. Both patients had excellent stability and were functioning at high levels of activity for their age (eg, hiking, skydiving). Both patients had radiographic signs of arthritis, which lowered 1 subject’s IKDC score to “C.” Conclusion: Knee dislocations have rare long-term excellent results, and most intermediate-term studies show fair to good functional results. By following fundamental principles in the management of a dislocated knee, patients can be given the opportunity to function at high levels. Hopefully, continued advances in the evaluation and treatment of knee dislocations will improve the long-term outcomes for these patients in the

  9. The Association Between Knee Confidence and Muscle Power, Hop Performance, and Postural Orientation in People With Anterior Cruciate Ligament Injury.

    PubMed

    Ageberg, Eva; Roos, Ewa M

    2016-06-01

    Study Design Cross-sectional. Background The association between muscle function and lack of knee confidence in people with anterior cruciate ligament (ACL) injury has not been well investigated. Such knowledge would help in the design of training programs for this population. Objective To investigate associations between self-reported knee confidence and muscle function in patients with ACL injury. Methods Cross-sectional data from 54 patients (mean age, 30 years; range, 20-39 years; 28% women) with ACL injury, treated with training and reconstructive surgery (n = 36) or training only (n = 18), were assessed 3 ± 1 years after injury. Univariate and multivariable ordinal regression analyses were conducted to test the association between the patient's knee confidence (question 3 from the Knee injury and Osteoarthritis Outcome Score as the dependent variable) and performance on tests of muscle power, hop performance, and postural orientation (test for substitution patterns score) as independent variables (absolute value on the injured leg, and limb symmetry index [LSI; injured leg/uninjured leg × 100] or absolute difference between the injured and uninjured legs). Results Sixteen patients reported no trouble with lack of knee confidence, 24 mild trouble, 10 moderate trouble, and 4 severe or extreme trouble. Univariate analyses revealed significant associations between worse knee confidence and lower (worse) LSIs for knee extension power, vertical jump, and side hop, and worse test for substitution patterns scores. In the multivariable analysis, worse vertical jump LSI (P = .043) and worse side hop LSI (P = .012) significantly accounted for 25% of the variation in perceived knee confidence. Conclusion Between-leg differences during demanding tasks are associated with knee confidence in individuals with ACL injury. J Orthop Sports Phys Ther 2016;46(6):477-482. Epub 26 Apr 2016. doi:10.2519/jospt.2016.6374. PMID:27117728

  10. FUNCTIONAL PERFORMANCE AND KNEE LAXITY IN NORMAL INDIVIDUALS AND IN INDIVIDUALS SUBMITTED TO ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

    PubMed Central

    de Vasconcelos, Rodrigo Antunes; Bevilaqua-Grossi, Débora; Shimano, Antonio Carlos; Jansen Paccola, Cleber Antonio; Salvini, Tânia Fátima; Prado, Christiane Lanatovits; Mello Junior, Wilson A.

    2015-01-01

    The aim of this study was to analyze the correlation between deficits in the isokinetic peak torque of the knee extensors and flexors with hop tests, postoperative knee laxity and functional scores in normal and ACL- reconstructed subjects with patellar tendon and hamstring tendon autografts. Methods: Sixty male subjects were enrolled and subdivided into three groups: Twenty subjects without knee injuries (GC group) and two groups of 20 subjects submitted to ACL reconstruction with patellar tendon (GTP group) and hamstrings autograft (GTF group). Results: The results showed significant correlation between knee extensors peak torque and performance in the hop tests for GTF and GC groups. There are no significantly correlations between post op knee laxity and Lysholm score compared with the hop tests and peak torque deficits. Concerning the differences between groups, the GTP group showed greater peak torque deficits in knee extensors, worst Lysholm scores and higher percentage of individuals with lower limb symmetry index (ISM) < 90% in both hop tests when compared to the other two groups. Conclusion: It is not recommendable to use only one measurement instrument for the functional evaluation of ACL-reconstructed patients, because significant correlation between peak torque, subject's functional score, knee laxity and hop tests were not observed in all groups. PMID:26998464

  11. Lateral Knee Pain after Outside-in Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction Using the TightRope RT

    PubMed Central

    Kuribayashi, So; Nakayama, Shuichi; Nakazato, Keisuke; Fukubayashi, Toru; Okinaga, Shuji

    2016-01-01

    The anterior cruciate ligament (ACL) TightRope RT (TR) was recently introduced as a novel cortical suspension device for ACL reconstruction. It has an adjustable graft loop that gives the surgeon some advantages during ACL reconstruction. We report three patients who required removal of the TR after an outside-in anatomical ACL reconstruction because of lateral knee pain. We assumed that the knee pain was associated with friction between the TR button of the posterolateral bundle and iliotibial band (ITB). Placing the TR button close to the lateral epicondyle and tissue interposition between the TR button and lateral femoral cortex may be potential risk factors for ITB irritation. Therefore, we recommend not placing the TR button close to the top of the lateral epicondyle and reducing the tissue interposition between the TR button and lateral femoral cortex as much as possible. PMID:26955618

  12. Magnetic Resonance Imaging of the Knee

    PubMed Central

    Hash, Thomas W.

    2013-01-01

    Context: Magnetic resonance imaging (MRI) affords high-resolution visualization of the soft tissue structures (menisci, ligaments, cartilage, etc) and bone marrow of the knee. Evidence Acquisition: Pertinent clinical and research articles in the orthopaedic and radiology literature over the past 30 years using PubMed. Results: Ligament tears can be accurately assessed with MRI, but distinguishing partial tears from ruptures of the anterior cruciate ligament (ACL) can be challenging. Determining the extent of a partial tear is often extremely difficult to accurately assess. The status of the posterolateral corner structures, menisci, and cartilage can be accurately evaluated, although limitations in the evaluation of certain structures exist. Patellofemoral joint, marrow, tibiofibular joint, and synovial pathology can supplement physical examination findings and provide definitive diagnosis. Conclusions: MRI provides an accurate noninvasive assessment of knee pathology. PMID:24381701

  13. Femoral press-fit fixation in ACL reconstruction using bone-patellar tendon-bone autograft: results at 15 years follow-up

    PubMed Central

    2012-01-01

    Background If anterior cruciate ligament (ACL) reconstruction is to be performed, decision regarding graft choice and its fixation remains one of the most controversial. Multiple techniques for ACL reconstruction are available. To avoid disadvantages related to fixation devices, a hardware-free, press-fit ACL reconstruction technique was developed. The aim of this study was to evaluate clinical outcome and osteoarthritis progression in long term after ACL reconstruction with central third patellar-tendon autograft fixed to femur by press-fit technique. Methods Fifty two patients met inclusion/excusion criteria for this study. The patients were assessed preoperatively and at 15 years after surgery with International Knee Documentation Committee Knee Ligament Evaluation Form, Lysholm knee score, Tegner activity scale and radiographs. Results Good overall clinical outcomes and self-reported assessments were documented, and remained good at 15 years. The mean Lysholm and Tegner scores improved from 59.7 ± 18.5 and 4.2 ± 1.0 preoperatively to 86.4 ± 5.6 (p = 0.004) and 6.9 ± 1.4 (p = 0.005) respectively at follow-up. The IKDC subjective score improved from 60.1 ± 9.2 to 80.2 ± 8.1 (p = 0.003). According to IKDC objective score, 75% of patients had normal or nearly normal knee joints at follow-up. Grade 0 or 1 results were seen in 85% of patients on laxity testing. Degenerative changes were found in 67% of patients. There was no correlation between arthritic changes and stability of knee and subjective evaluation (p > 0.05). Conclusions ACL reconstruction with patellar tendon autograft fixed to femur with press-fit technique allows to achieve good self-reported assessments and clinical ligament evaluation up to 15 years. Advantages of the bone-patellar-tendon-bone (BPTB) press-fit fixation include unlimited bone-to-bone healing, cost effectiveness, avoidance of disadvantages associated with hardware, and ease for

  14. ACL reconstruction in sports active people: transtibial DB technique with ST/G vs. transtibial SB technique with BPTB: preliminary results.

    PubMed

    Volpi, Piero; Cervellin, Matteo; Denti, Matteo; Bait, Corrado; Melegati, Gianluca; Quaglia, Alessandro; de Girolamo, Laura

    2010-11-01

    The single-bundle ACL reconstruction ensures good outcomes and it is a well-established and widespread technique. Nevertheless, some patients still present residual pain and instability. Recent studies have showed that the double-bundle technique restores better natural ACL-fitting kinematics. Long-term clinical studies comparing the two surgical techniques are not frequent and there is no instrument to evaluate function and kinematics during the knee rotation in vivo. In this randomised prospective study performed on sportive people, we compare the BPTB single-bundle ACL reconstruction technique, which is the most common surgical technique performed on these patients' category, with the ACL double-bundle reconstruction technique (DB), in order to evaluate possible differences between the groups. Comparing the two groups, no statistically significant difference regarding the post-operative Lysholm score (p=0.368) the Tegner activity scale (p=0.519) and the arthrometric evaluation with KT-1000 (p=0.74) have been observed. On the contrary, the IKDC evaluation showed a statistically significant difference (p=0.004) better results of the DB group. Moreover, as assessed by the Tegner activity scale, only patients of the DB group were able to return to sports at a pre-injury level. Our data suggest that the double bundle ST/G ACL reconstruction technique results into slightly better outcome than the traditional technique of single-bundle BPTB. The verification and quantification of the advantages of this technique is anticipated with future studies focusing to the accurate measurement of knee rotation during different activities. PMID:20934698

  15. [Age, activity and strength of knee ligaments].

    PubMed

    Kasperczyk, W J; Rosocha, S; Bosch, U; Oestern, H J; Tscherne, H

    1991-07-01

    The cruciate ligaments of older persons are thought to have diminished biomechanical properties. On the other hand, joint immobilization also leads to similar functional losses in ligaments. It can be difficult to differentiate between these factors in older and immobile persons. The anterior and posterior cruciate ligaments of six younger (average age 30 years) and six older (average age 64.7 years) donors with similar levels of activity were subjected to biomechanical testing. Each sample had to meet the following conditions: appropriate age, no chronic vascular and cardiopulmonary disease found on autopsy, no signs of osteoarthrosis and no knee injuries. The material properties of maximum stress (e.g. ACL: young/old 24/21N/mm2), elastic modulus (e.g. ACL: young/old 144/129 MPa), and strain (e.g. ACL: young/old 25/28%), did not differ significantly (p less than 0.05). This indicates that older persons who are active do not necessarily show functional losses in the cruciate ligaments. Other data found in the literature can be ascribed to immobilization influences. In this data many of the older test persons had chronic vascular insufficiency, cardiopulmonary disease or malignancies. PMID:1925614

  16. Comparison of grafts for anatomical reconstruction of the ACL: patellar versus semitendinosus/gracilis☆

    PubMed Central

    Bitun, Patrícia Barros; Miranda, Carlos Roberto; Escudero, Ricardo Boso; Araf, Marcelo; de Souza, Daphnis Gonçalves

    2015-01-01

    Objective To compare the functional results from surgical treatment for anatomical reconstruction of the anterior cruciate ligament (ACL) with a single band, using two types of autologous grafts. Methods Twenty-seven patients who underwent anatomical reconstruction of the ACL by means of the Chambat technique were evaluated prospectively. They were divided into two groups: A, with 14 patients, using grafts from flexor tendons; and B, with 13 patients, using grafts from the patellar tendon. In both groups, fixation was performed using an absorbable interference screw. Results Based on the Lysholm score, group A presented a mean score of 71.6 in the first month, while B presented 75. At the end of the sixth month, both groups presented 96.6. Evaluation of the total IKDC showed that in the first month, the majority of the patients, both in group A (85.7%) and in group B (76.9%), presented a knee assessment that was close to normal. In the sixth month, 92.9% of group A had normal presentations, and 100% of group B. Conclusion According to the Lysholm functional evaluation and the IKDC subjective assessment, there was no statistically significant difference in the results between the groups, and the results were better in the sixth month. PMID:26229896

  17. Return to sport after ACL reconstruction: how, when and why? A narrative review of current evidence.

    PubMed

    Zaffagnini, Stefano; Grassi, Alberto; Serra, Margherita; Marcacci, Maurilio

    2015-01-01

    Allowing a patient to return to sport and unrestricted physical activity after ACL injury and reconstruction is one of the most challenging and difficult decisions an orthopaedic surgeon has to make. Indeed, many factors have to be taken into account before it can be considered safe for a patients to load a reconstructed knee. The current literature contains plenty of studies aimed at evaluating return to sport, and the factors that may affect or predict this outcome, e.g. intrinsic factors like genetics, biology, type of lesion, anatomical features, motivation and psychology, and extrinsic factors such as graft type, surgical technique, rehabilitation protocols, and biological support. It is possible that awareness of these issues could help the clinician to optimise outcomes, and possibly avoid failures too, although as yet no universal criteria for resuming sport have been produced. PMID:26151036

  18. Return to sport after ACL reconstruction: how, when and why? A narrative review of current evidence

    PubMed Central

    ZAFFAGNINI, STEFANO; GRASSI, ALBERTO; SERRA, MARGHERITA; MARCACCI, MAURILIO

    2015-01-01

    Allowing a patient to return to sport and unrestricted physical activity after ACL injury and reconstruction is one of the most challenging and difficult decisions an orthopaedic surgeon has to make. Indeed, many factors have to be taken into account before it can be considered safe for a patients to load a reconstructed knee. The current literature contains plenty of studies aimed at evaluating return to sport, and the factors that may affect or predict this outcome, e.g. intrinsic factors like genetics, biology, type of lesion, anatomical features, motivation and psychology, and extrinsic factors such as graft type, surgical technique, rehabilitation protocols, and biological support. It is possible that awareness of these issues could help the clinician to optimise outcomes, and possibly avoid failures too, although as yet no universal criteria for resuming sport have been produced. PMID:26151036

  19. Neuromuscular Changes After Aerobic Exercise in People with Anterior Cruciate Ligament– Reconstructed Knees

    PubMed Central

    Dalton, Elizabeth C.; Pfile, Kate R.; Weniger, Gerald R.; Ingersoll, Christopher D.; Herman, Daniel; Hart, Joseph M.

    2011-01-01

    Context: Anterior cruciate ligament (ACL) reconstructions are common, especially in young, active people. The lower extremity neuromuscular adaptations seen after aerobic exercise provide information about how previously injured patients perform and highlight deficits and, hence, areas for focused treatment. Little information is available about neuromuscular performance after aerobic exercise in people with ACL reconstructions. Objective: To compare dynamic balance, gluteus medius muscle activation, vertical jump height, and hip muscle strength after aerobic exercise in people with ACL-reconstructed knees. Design: Case-control study. Setting: Research laboratory. Patients or Other Participants: Of 34 recreationally active volunteers, 17 had a unilateral primary ACL reconstruction at least 2 years earlier and 17 were matched controls. Intervention(s): All participants performed 20 minutes of aerobic exercise on a treadmill. Main Outcome Measure(s): We recorded dynamic, single-legged balance electromyographic gluteus medius muscle activation, single-legged vertical jump height, and maximum isometric strength for hip abduction, extension, and external rotation preexercise and postexercise. Results: Participants with ACL reconstructions exhibited shorter reach distances during dynamic balance tasks, indicating poorer dynamic balance, and less gluteus medius muscle electromyographic activation. Reductions in hip abduction and extension strength after exercise were noted in all participants; however, those with ACL reconstructions displayed greater hip extensor strength loss after aerobic exercise than did the control group. Conclusions: Neuromuscular changes after aerobic exercise exist in both patients with ACL reconstructions and controls. The former group may experience greater deficits in hip extensor strength after aerobic exercise. Reduced reach distances in people with ACL reconstructions may represent a protective mechanism against excessive tibiofemoral

  20. Patterns and Influencing Factors of Medial Meniscus Tears in Varus Knee Osteoarthritis

    PubMed Central

    Cho, Sung-Do; Kim, Jong-Hyun; Cho, Hye-Yong; Kim, Kwang-Ho

    2016-01-01

    Purpose To investigate the patterns of medial meniscus (MM) tears in patients with varus knee osteoarthritis who underwent total knee arthroplasty and analyze the factors that could affect MM tears. Materials and Methods The patients (365 knees, 268 patients) were classified into three groups; group I with MM posterior horn (PH) tear only; group II with MM root tear only; and group III with MMPH plus root tear. The following factors were evaluated: age, gender, body mass index, varus deviation of the mechanical axis, medial proximal tibial angle, posterior tibial slope (PTS), and anterior cruciate ligament (ACL) integrity (normal, degeneration, and tear or absence). Results MM tears were identified in all knees. The patterns of the combined MMPH tears in group III were less complex than those in group I. Varus deviation and PTS were significantly greater in group III than groups I and II. In group III, there were significantly more cases of ACL tear or absence than groups I and II. The others showed no differences among three groups. Conclusions Severe varus knee osteoarthritis was always accompanied by MM tears. Risk factors for MMPH plus root tears were severe varus deformity, great PTS, and ACL tear or absence. PMID:27274471

  1. In vivo bone tunnel remodeling in symptomatic patients after ACL reconstruction: a retrospective comparison of articular and extra-articular fixation

    PubMed Central

    Mathis, Dominic T.; Rasch, Helmut; Hirschmann, Michael T.

    2015-01-01

    Summary Background there is only a paucity of studies dealing with bone remodeling within the tunnels after anterior cruciate ligament (ACL) reconstruction. The objective of this study was to evaluate the influence of tendon graft type and surgical fixation technique on bone tunnel remodeling in patients with symptomatic knees after ACL reconstruction. Methods in a retrospective study 99mTc-HDP bone tracer uptake (BTU) in SPECT/CT of 57 knees with symptoms of pain and/or instability after ACL reconstruction was investigated. All 57 knees were subdivided according their anatomy (femur and tibia), fixation (articular versus extra-articular fixation) and graft types into eight groups: femoral-articular versus extra-articular fixation using bone-patellar tendon-bone (BPTB) and hamstring autografts; tibial-articular versus extra-articular fixation using patellar tendon and hamstring autografts; BTU grading for each area of the localisation scheme were recorded. Tunnel diameter and length was measured in the CT scans. Results BTU was higher for the articular fixation in the femur and for the extra-articular fixation in the tibial tunnel. Patellar tendon graft fixation showed a significantly higher BTU in the superior-lateral and posterior-central area of the tibia, meaning the areas of the tibial tunnel near the entrance into the joint. Tunnel enlargement correlated significantly with increased BTU (p<0.05). Conclusion assessment of in vivo bone tunnel remodelling in symptomatic patients after ACL reconstruction revealed different patterns of BTU with regards to graft and fixation method. PMID:26958543

  2. Biomechanical Analysis of Simulated Clinical Testing and Reconstruction of the Anterolateral Ligament of the Knee

    PubMed Central

    Spencer, Luke; Burkhart, Timothy A.; Tran, Michael N.; Rezansoff, Alex James; Deo, Shaneel; Caterine, Scott; Getgood, Alan M

    2016-01-01

    Background: Anatomic anterolateral ligament (ALL) reconstruction has been proposed to assist anterior cruciate ligament (ACL) reconstruction in controlling anterolateral rotational laxity of the knee. However, the biomechanical effects have not been reported. Purpose: (1) To investigate the effect of ALL transection on rotational knee kinematics and (2) to determine the effect on knee biomechanics of ALL reconstruction procedures compared with lateral extra-articular tenodesis (LET). Study Design: Controlled laboratory study. Methods: A total of 12 cadaveric knee specimens were tested in the following sequence: (1) ACLintact, (2) anteromedial bundle of ACL sectioned (ACLamb), (3) complete ACL sectioned (ACLfull), (4) ALL sectioned (ALLsec), (5) anatomic ALL reconstruction (ALLanat), and (6) LET. Biomechanical anterior drawer and Lachman tests were performed in which a 90-N load was applied to the posterior tibia, and anterior translation was measured. A combined load to simulate the early phase of the pivot-shift test was executed in which a 5-N·m internal rotation moment was applied to a fully extended knee; anterior translation and internal rotation were measured. Results: Anterior translation increased across conditions for the biomechanical tests. Internal rotation during the simulated early-phase pivot-shift test was significantly different between ACLfull and ALLsec. Anatomic ALL reconstruction did not significantly reduce internal rotation or anterior translation during the simulated early-phase pivot-shift test. After LET, a significant decrease in anterior translation was found. There was no evidence of over-constraint of the knee with either anatomic ALL reconstruction or LET. Conclusion: The ALL demonstrated a role in controlling anterolateral laxity. LET had a composite effect in governing both anterior and rotational laxity. Anatomic ALL reconstruction did not reduce anterolateral rotational laxity. Clinical Relevance: Profiling the biomechanical

  3. Multicenter Orthopaedic Outcome Network Early Anti-inflammatory Treatment in Patients with Acute ACL Tear” (MOON-AAA) Clinical Trial

    PubMed Central

    Lattermann, Christian; Proffitt, Mary; Huston, Laura J.; Gammon, Lee; Johnson, Darren L.; Kraus, Virginia B.; Spindler, Kurt P.

    2016-01-01

    Objectives: We present the early results from the “Multicenter Orthopaedic Outcome Network Early Anti-inflammatory Treatment in Patients with Acute ACL Tear and Painful Effusions” (MOON-AAA) clinical trial (figure 1). This trial allows for a well controlled prospective cohort of patients with isolated ACL injury at risk for OA. We compared the effect of a single versus a repeated dosage of Kenalog within the first two weeks after ACL injury and its effect on chondral degradation in the first 4 weeks prior to surgical reconstruction of the ACL. Methods: 49 patients with isolated ACL tears were enrolled. Knee joints were aspirated and patients received an injection with 40 mg Kenalog either within 4 days, 10 days, both time points or not at all (saline injection control). Serum, synovial fluid and urine were collected at 3 time points. Permutated block randomization, triple blinding, independent monitoring and standardized x-ray was performed to comply with GCP standards. Patient reported outcomes were collected at 6 time points up to 6 months post-ACL reconstruction(IKDC, KOOS and Marx activity level). A standardized synovial fluid biomarker panel was analyzed according to OARSI guidelines. Statistical analysis were performed using SAS mixed models analysis. Results: Serum analysis shows significant change after injury. Chondrodegradatory markers such as CTX-II, MMP-1 and MMP-3 as well as COMP indicate a progressive destruction of chondral matrix and collagen breakdown . There is a dramatic (250%) increase of CTX-II in the first 4 weeks. Matrix proteins such as MMP-1 and 3 as well as COMP show an initial increase and then a steep decline (see figure 1). Inflammatory markers (IL-1 alpha, IL-1beta, IRAP) show a decline from the time of injury. IL-1 alpha, however shows a dramatic uptake after week 2. This longitudinal data confirms a dramatic onset of early osteoarthritic biomarker profiles immediately after ACL injury as measured in synovial fluid

  4. Posteromedial Corner of the Knee: The Neglected Corner.

    PubMed

    Lundquist, Ryan B; Matcuk, George R; Schein, Aaron J; Skalski, Matthew R; White, Eric A; Forrester, Deborah M; Gottsegen, Christopher J; Patel, Dakshesh B

    2015-01-01

    The posteromedial corner of the knee (PMC) is an important anatomic structure that is easily seen but often overlooked on magnetic resonance (MR) images. Whereas the posterolateral corner has been referred to as the "dark side of the knee" by some authors owing to widespread lack of knowledge of its complex anatomy, even less is written about the PMC; yet it is as important as the posterolateral corner in multiligament injuries of the knee. The PMC lies between the posterior margin of the longitudinal fibers of the superficial medial collateral ligament (MCL) and the medial border of the posterior cruciate ligament (PCL). The anatomy of the PMC can be complex and the literature describing it can be confusing, at times oversimplifying it and at other times adding unnecessary complexity. Its most important structures, however, can be described more simply as five major components, and can be better shown with illustrations that emphasize the anatomic distinctions. Injuries to the PMC are important to recognize, as disruption of the supporting structures can cause anteromedial rotational instability (AMRI). Isolated PMC injuries are rare; most occur in conjunction with injuries to other important stabilizing knee structures such as the anterior cruciate ligament (ACL) and PCL. Unrecognized and unaddressed injury of the PMC is one of the causes of ACL and PCL graft failures. Recognition of PMC injuries is critical, as the diagnosis will often change or require surgical management. PMID:26172356

  5. Differences in muscle strength after ACL reconstruction do not influence cardiorespiratory responses to isometabolic exercise

    PubMed Central

    Andrade, Marília S.; Lira, Claudio A. B.; Vancini, Rodrigo L.; Nakamoto, Fernanda P.; Cohen, Moisés; Silva, Antonio C.

    2014-01-01

    Objectives To investigate whether the muscle strength decrease that follows anterior cruciate ligament (ACL) reconstruction would lead to different cardiorespiratory adjustments during dynamic exercise. Method Eighteen active male subjects were submitted to isokinetic evaluation of knee flexor and extensor muscles four months after ACL surgery. Thigh circumference was also measured and an incremental unilateral cardiopulmonary exercise test was performed separately for both involved and uninvolved lower limbs in order to compare heart rate, oxygen consumption, minute ventilation, and ventilatory pattern (breath rate, tidal volume, inspiratory time, expiratory time, tidal volume/inspiratory time) at three different workloads (moderate, anaerobic threshold, and maximal). Results There was a significant difference between isokinetic extensor peak torque measured in the involved (116.5±29.1 Nm) and uninvolved (220.8±40.4 Nm) limbs, p=0.000. Isokinetic flexor peak torque was also lower in the involved limb than in the uninvolved limb (107.8±15.4 and 132.5±26.3 Nm, p=0.004, respectively). Lower values were also found in involved thigh circumference as compared with uninvolved limb (46.9±4.3 and 48.5±3.9 cm, p=0.005, respectively). No differences were found between the lower limbs in any of the variables of the incremental cardiopulmonary tests at all exercise intensities. Conclusions Our findings indicate that, four months after ACL surgery, there is a significant deficit in isokinetic strength in the involved limb, but these differences in muscle strength requirement do not produce differences in the cardiorespiratory adjustments to exercise. Based on the hypotheses from the literature which explain the differences in the physiological responses to exercise for different muscle masses, we can deduce that, after 4 months of a rehabilitation program after an ACL reconstruction, individuals probably do not present differences in muscle oxidative and peripheral

  6. Assessing 3D tunnel position in ACL reconstruction using a novel single image 3D-2D registration

    NASA Astrophysics Data System (ADS)

    Kang, X.; Yau, W. P.; Otake, Y.; Cheung, P. Y. S.; Hu, Y.; Taylor, R. H.

    2012-02-01

    The routinely used procedure for evaluating tunnel positions following anterior cruciate ligament (ACL) reconstructions based on standard X-ray images is known to pose difficulties in terms of obtaining accurate measures, especially in providing three-dimensional tunnel positions. This is largely due to the variability in individual knee joint pose relative to X-ray plates. Accurate results were reported using postoperative CT. However, its extensive usage in clinical routine is hampered by its major requirement of having CT scans of individual patients, which is not available for most ACL reconstructions. These difficulties are addressed through the proposed method, which aligns a knee model to X-ray images using our novel single-image 3D-2D registration method and then estimates the 3D tunnel position. In the proposed method, the alignment is achieved by using a novel contour-based 3D-2D registration method wherein image contours are treated as a set of oriented points. However, instead of using some form of orientation weighting function and multiplying it with a distance function, we formulate the 3D-2D registration as a probability density estimation using a mixture of von Mises-Fisher-Gaussian (vMFG) distributions and solve it through an expectation maximization (EM) algorithm. Compared with the ground-truth established from postoperative CT, our registration method in an experiment using a plastic phantom showed accurate results with errors of (-0.43°+/-1.19°, 0.45°+/-2.17°, 0.23°+/-1.05°) and (0.03+/-0.55, -0.03+/-0.54, -2.73+/-1.64) mm. As for the entry point of the ACL tunnel, one of the key measurements, it was obtained with high accuracy of 0.53+/-0.30 mm distance errors.

  7. [Jumper's knee].

    PubMed

    Hagner, W; Sosnowski, S; Kaziński, W; Frankowski, S

    1993-01-01

    A series of 30 athletes aged about 16 years on an average, exposed to activities putting a strain on the patellar tendon during training has been examined. They were involved in competitive sports for 3 years on an average. In 27 per cent of them jumpers knee symptoms have been found. PMID:7671664

  8. Gender Differences among Sagittal Plane Knee Kinematic and Ground Reaction Force Characteristics during a Rapid Sprint and Cut Maneuver

    ERIC Educational Resources Information Center

    James, C. Roger; Sizer, Phillip S.; Starch, David W.; Lockhart, Thurmon E.; Slauterbeck, James

    2004-01-01

    Women are more prone to anterior cruciate ligament (ACL) injury during cutting sports than men. The purpose of this study was to examine knee kinematic and ground reaction forces (GRF) differences between genders during cutting. Male and female athletes performed cutting trials while force platform and video data were recorded (180 Hz).…

  9. Gender, Vertical Height and Horizontal Distance Effects on Single-Leg Landing Kinematics: Implications for Risk of non-contact ACL Injury.

    PubMed

    Ali, Nicholas; Rouhi, Gholamreza; Robertson, Gordon

    2013-01-01

    There is a lack of studies investigating gender differences in whole-body kinematics during single-leg landings from increasing vertical heights and horizontal distances. This study determined the main effects and interactions of gender, vertical height, and horizontal distance on whole-body joint kinematics during single-leg landings, and established whether these findings could explain the gender disparity in non-contact anterior cruciate ligament (ACL) injury rate. Recreationally active males (n=6) and females (n=6) performed single-leg landings from a takeoff deck of vertical height of 20, 40, and 60 cm placed at a horizontal distance of 30, 50 and 70 cm from the edge of a force platform, while 3D kinematics and kinetics were simultaneously measured. It was determined that peak vertical ground reaction force (VGRF) and the ankle flexion angle exhibited significant gender differences (p=0.028, partial η(2)=0.40 and p=0.035, partial η(2)=0.37, respectively). Peak VGRF was significantly correlated to the ankle flexion angle (r= -0.59, p=0.04), hip flexion angle (r= -0.74, p=0.006), and trunk flexion angle (r= -0.59, p=0.045). Peak posterior ground reaction force (PGRF) was significantly correlated to the ankle flexion angle (r= -0.56, p=0.035), while peak knee abduction moment was significantly correlated to the knee flexion angle (r= -0.64, p=0.03). Rearfoot landings may explain the higher ACL injury rate among females. Higher plantar-flexed ankle, hip, and trunk flexion angles were associated with lower peak ground reaction forces, while higher knee flexion angle was associated with lower peak knee abduction moment, and these kinematics implicate reduced risk of non-contact ACL injury. PMID:24146702

  10. Anteromedial portal versus transtibial drilling techniques in ACL reconstruction: a blinded cross-sectional study at two- to five-year follow-up

    PubMed Central

    Alentorn-Geli, Eduard; Samitier, Gonzalo; Álvarez, Pedro; Steinbacher, Gilbert

    2010-01-01

    Drilling of the femoral tunnel with the transtibial (TT) technique is widely used in bone-patellar tendon-bone (BPTB) anterior cruciate ligament (ACL) reconstruction. Recent studies suggest higher knee stability with the use of the anteromedial portal (AMP). The purpose of this study was to compare functional and clinical outcomes of BPTB ACL reconstruction using the TT or the AMP technique for drilling the femoral tunnel. All ACL reconstructions between January 2003 and April 2006 were approached for eligibility. Forty-seven patients met inclusion criteria (21 TT group and 26 AMP group). Blinded assessments of IKDC score, knee stability and range of motion, one-leg hop test, mid-quadriceps circumference, VAS for satisfaction with surgery, Lysholm and Tegner scores, and SF-12 questionnaire were obtained for both groups. Data on preoperative and postoperative surgical timing were retrospectively reviewed through the charts. The AMP group demonstrated a significantly lower recovery time from surgery to walking without crutches (p < 0.01), to return to normal life (p < 0.03), to return jogging (p < 0.03), to return training (p < 0.03), and to return to play (p < 0.03). Knee stability values measured with KT-1000, Lachman test, pivot-shift sign, and objective IKDC score assessments were significantly better for the AMP compared to TT group (p < 0.002, p < 0.03, p < 0.02, p < 0.015, respectively). No differences were found for VAS for satisfaction with surgery, Lysholm, Tegner, and SF-12 between both groups. The use of the AMP technique significantly improved the anterior-posterior and rotational knee stability, IKDC scores, and recovery time from surgery compared to the TT technique. PMID:20401753

  11. Gender, Vertical Height and Horizontal Distance Effects on Single-Leg Landing Kinematics: Implications for Risk of non-contact ACL Injury

    PubMed Central

    Ali, Nicholas; Rouhi, Gholamreza; Robertson, Gordon

    There is a lack of studies investigating gender differences in whole-body kinematics during single-leg landings from increasing vertical heights and horizontal distances. This study determined the main effects and interactions of gender, vertical height, and horizontal distance on whole-body joint kinematics during single-leg landings, and established whether these findings could explain the gender disparity in non-contact anterior cruciate ligament (ACL) injury rate. Recreationally active males (n=6) and females (n=6) performed single-leg landings from a takeoff deck of vertical height of 20, 40, and 60 cm placed at a horizontal distance of 30, 50 and 70 cm from the edge of a force platform, while 3D kinematics and kinetics were simultaneously measured. It was determined that peak vertical ground reaction force (VGRF) and the ankle flexion angle exhibited significant gender differences (p=0.028, partial η 2 =0.40 and p=0.035, partial η 2 =0.37, respectively). Peak VGRF was significantly correlated to the ankle flexion angle (r= −0.59, p=0.04), hip flexion angle (r= −0.74, p=0.006), and trunk flexion angle (r= −0.59, p=0.045). Peak posterior ground reaction force (PGRF) was significantly correlated to the ankle flexion angle (r= −0.56, p=0.035), while peak knee abduction moment was significantly correlated to the knee flexion angle (r= −0.64, p=0.03). Rearfoot landings may explain the higher ACL injury rate among females. Higher plantar-flexed ankle, hip, and trunk flexion angles were associated with lower peak ground reaction forces, while higher knee flexion angle was associated with lower peak knee abduction moment, and these kinematics implicate reduced risk of non-contact ACL injury. PMID:24146702

  12. Dynamic knee stability estimated by finite helical axis methods during functional performance approximately twenty years after anterior cruciate ligament injury.

    PubMed

    Grip, Helena; Tengman, Eva; Häger, Charlotte K

    2015-07-16

    Finite helical axis (FHA) measures of the knee joint during weight-bearing tasks may capture dynamic knee stability following Anterior Cruciate Ligament (ACL) injury. The aim was to investigate dynamic knee stability during two-leg squat (TLS) and one-leg side hop (SH) in a long-term follow-up of ACL injury, and to examine correlations with knee laxity (KT-1000), osteoarthritis (OA, Kellgren-Lawrence) and knee function (Lysholm score). Participants were injured 17-28 years ago and then treated with surgery (n=33, ACLR) or physiotherapy only (n=37, ACLPT) and healthy-knee controls (n=33) were tested. Movements were registered with an optical motion capture system. We computed three FHA inclination angles, its' Anterior-Posterior (A-P) position, and an index quantifying directional changes (DI), during stepwise knee flexion intervals of ∼15°. Injured knees were less stable compared to healthy controls' and to contralateral non-injured knees, regardless of treatment: the A-P intersection was more anterior (indicating a more anterior positioning of tibia relative to femur) positively correlating with high laxity/low knee function, and during SH, the FHA was more inclined relative to the flexion-extension axis, possibly due to reduced rotational stability. During the TLS, A-P intersection was more anterior in the non-injured knee than the injured, and DI was higher, probably related to higher load on the non-injured knee. ACLR had less anterior A-P intersection than ACLPT, suggesting that surgery enhanced stability, although rotational stability may remain reduced. More anterior A-P intersection and greater inclination between the FHA and the knee flexion-extension axis best revealed reduced dynamic stability ∼23 years post-injury. PMID:25935685

  13. ACL reconstruction in a teenage athlete with fibular hemimelia.

    PubMed

    Mascarenhas, Randy; Simon, David; Forsythe, Brian; Harner, Christopher D

    2014-03-01

    Fibular hemimelia exists as a rare cause of ACL insufficiency. This case report concerns the diagnosis and treatment of anterior cruciate ligament insufficiency in a teenage football player with fibular hemimelia. While ACL reconstruction has been described to allow activities of daily living in this patient population, this is the first report in the literature of anterior cruciate ligament reconstruction in an athlete with fibular hemimelia. We believe that ACL reconstruction is a viable and beneficial treatment option in the care of a symptomatic patient with congenital absence of the ACL and can allow athletes with this condition to return not only to their previous functional level, but also to their previous level of play. PMID:24238853

  14. 50 CFR 648.290 - Tilefish Annual Catch Limit (ACL).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... the ABC recommended by the SSC. (1) (2) Periodicity. The tilefish commercial ACL may be established on...-year ABC recommendations. (b) Performance review. The Tilefish Monitoring Committee shall conduct...

  15. 50 CFR 648.290 - Tilefish Annual Catch Limit (ACL).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... the ABC recommended by the SSC. (1) (2) Periodicity. The tilefish commercial ACL may be established on...-year ABC recommendations. (b) Performance review. The Tilefish Monitoring Committee shall conduct...

  16. 50 CFR 648.290 - Tilefish Annual Catch Limit (ACL).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... the ABC recommended by the SSC. (1) (2) Periodicity. The tilefish commercial ACL may be established on...-year ABC recommendations. (b) Performance review. The Tilefish Monitoring Committee shall conduct...

  17. 50 CFR 648.160 - Bluefish Annual Catch Limit (ACL).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... the ABC recommended by the SSC. (1) Periodicity. The bluefish fishery ACL may be established on an... ABC recommendations. (2) (b) Performance review. The Bluefish Monitoring Committee shall conduct...

  18. 50 CFR 648.160 - Bluefish Annual Catch Limit (ACL).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... the ABC recommended by the SSC. (1) Periodicity. The bluefish fishery ACL may be established on an... ABC recommendations. (2) (b) Performance review. The Bluefish Monitoring Committee shall conduct...

  19. 50 CFR 648.160 - Bluefish Annual Catch Limit (ACL).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... the ABC recommended by the SSC. (1) Periodicity. The bluefish fishery ACL may be established on an... ABC recommendations. (2) (b) Performance review. The Bluefish Monitoring Committee shall conduct...

  20. Effect of Planning on Trunk Motion and Knee Moments During a Side Step Cut Task

    NASA Astrophysics Data System (ADS)

    Houck, Jeff; Gorniak, Stacey; Nicholson, Kristen

    2004-03-01

    Recent studies suggest that alterations in knee biomechanics associated with unanticipated cutting tasks place athletes at higher risk of knee injuries. Besier et al observed alterations in knee moments during unanticipated cutting tasks that were consistent with in-vitro ACL injury mechanisms. During similar tasks, Patla et al observed lateral trunk lean and decreased foot placement, suggesting that full body center of mass control is perturbed during such tasks. The purpose of this study was to compare the trunk and knee frontal plane moments and evaluate a relationship between the two during unanticipated cutting tasks. The results of this study suggest that there is a relationship between the trunk and knee frontal plane moments during the first 200-400ms of the stance phase of gait.

  1. Medial Foot Loading on Ankle and Knee Biomechanics

    PubMed Central

    Mitchell, Lyneil C.J.; Ford, Kevin R.; Minning, Stephen; Myer, Gregory D.; Mangine, Robert E.

    2008-01-01

    Background The incidence of anterior cruciate ligament (ACL) injuries among females continues at disproportionate rates compared to males, with research indicating inconclusive multifactorial causality. Data from previous retrospective studies suggest an effect of abnormal foot and ankle bio-mechanics on pathology at the knee, including the ACL. Objective To determine if a relationship exists between plantar foot loading patterns during normal gait and high risk biomechanics purported to increase risk of ACL injury. Methods Dynamic barefoot plantar pressure distribution was measured on 33 female collegiate soccer players. Groups were divided according to their predominant gait loading pattern (medial or lateral). Three dimensional (3-D) motion analysis was conducted during drop vertical jumps to assess vertical ground reaction force and discrete angle and joint moment variables of the lower extremities. Results No significant differences occured in sagittal or coronal plane knee joint kinematics and kinetics between the medial and lateral loading groups. Discussion Dynamic foot and ankle biomechanics during gait do not appear to be related to lower extremity kinematics or kinetics during landing in collegiate female soccer players. Conclusion The exact cause of the abnormal differences in female landing biomechanics has not been irrefutably defined. This study suggests no effect of foot and ankle biomechanics exists on the landing mechanics of female soccer players. PMID:20379384

  2. Diagnostic accuracy of Magnetic Resonance Imaging in assessment of Meniscal and ACL tear: Correlation with arthroscopy

    PubMed Central

    Yaqoob, Jamal; Alam, Muhammad Shahbaz; Khalid, Nadeem

    2015-01-01

    Objective: To determine the diagnostic accuracy of magnetic resonance imaging (MRI) in injuries related to anterior cruciate ligament and menisci and compare its effectiveness with that of arthroscopy. Methods: This retrospective cross-sectional study was conducted in the department of Radiology & Medical Imaging of Dallah Hospital, Riyadh, Kingdom of Saudi Arabia from September 2012 to March 2014. Fifty four patients (including 30 men and 24 women) with internal derangement of knee referred from the orthopedic consulting clinics underwent MR imaging followed by arthroscopic evaluation. The presence of meniscal and ligamentous abnormality on the imaging was documented by two trained radiologist. Findings were later compared with arthroscopic findings. Results: The sensitivity, specificity and accuracy of MR imaging for menisci and ACL injury were calculated: 100% sensitivity, 88.4% specificity, 90% positive predictive value, 100% negative predictive value, and 94.4% accuracy were noted for medial meniscal injury. Similarly, MR had sensitivity of 85.7%, specificity of 95%, positive predictive value of 85.7%, negative predictive value of 95%, and accuracy of 92.5% for lateral meniscal injuries. Likewise, anterior cruciate ligament had 91.6% sensitivity, 95.2% specificity, 84.6% positive predictive value, 97.5% negative predictive value, and 94.4% accuracy. Conclusion: MRI is extremely helpful in identifying meniscal and anterior cruciate ligaments tears. MR imaging has high negative predictive value making it better choice as screening tool compared to diagnostic arthroscopic evaluation in most patients with soft tissue trauma to knee. PMID:26101472

  3. Knee joint replacement - series (image)

    MedlinePlus

    ... than 3 blocks because of knee pain Loose knee prosthesis Some knee fractures ... an incision over the affected knee. The patella (knee cap) is moved ... helps the prosthesis to adhere better. The two parts of the ...

  4. Knee microfracture surgery

    MedlinePlus

    Cartilage regeneration - knee ... Three types of anesthesia may be used for knee arthroscopy surgery: Medicine to relax you, and shots of painkillers to numb the knee Spinal (regional) anesthesia General anesthesia (you will be ...

  5. Knee CT scan

    MedlinePlus

    CAT scan - knee; Computed axial tomography scan - knee; Computed tomography scan - knee ... Saunders; 2015:chap 93. Shaw AS, Prokop M. Computed tomography. In: Adam A, Dixon AK, Gillard JH, Schaefer- ...

  6. Knee joint replacement

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/002974.htm Knee joint replacement To use the sharing features on this page, please enable JavaScript. Knee joint replacement is a surgery to replace a knee ...

  7. Knee pain (image)

    MedlinePlus

    ... front of the knee can be due to bursitis, arthritis, or softening of the patella cartilage as ... knee. Overall knee pain can be due to bursitis, arthritis, tears in the ligaments, osteoarthritis of the ...

  8. Quantifying in vivo laxity in the anterior cruciate ligament and individual knee joint structures.

    PubMed

    Westover, L M; Sinaei, N; Küpper, J C; Ronsky, J L

    2016-11-01

    A custom knee loading apparatus (KLA), when used in conjunction with magnetic resonance imaging, enables in vivo measurement of the gross anterior laxity of the knee joint. A numerical model was applied to the KLA to understand the contribution of the individual joint structures and to estimate the stiffness of the anterior-cruciate ligament (ACL). The model was evaluated with a cadaveric study using an in situ knee loading apparatus and an ElectroForce test system. A constrained optimization solution technique was able to predict the restraining forces within the soft-tissue structures and joint contact. The numerical model presented here allowed in vivo prediction of the material stiffness parameters of the ACL in response to applied anterior loading. Promising results were obtained for in vivo load sharing within the structures. The numerical model overestimated the ACL forces by 27.61-92.71%. This study presents a novel approach to estimate ligament stiffness and provides the basis to develop a robust and accurate measure of in vivo knee joint laxity. PMID:27058613

  9. [Application and development of kinematical alighment during total knee arthroplasty].

    PubMed

    Zhang Guo-dong; Yang, Chen; Yang, Guang; Qi, Xin

    2015-12-01

    Kinematical alignment during total knee arthroplasty is an emerging process, and draws more and more attentions from scholars. Knee joint is close to normal joint after TKA through kinematical alighment, which has good clinical results and functional scores, and not increase failure probility. Thus, it may increase joint stress of patella-femur joint, lead to patellar maltracking and increase abrasion. The paper summarized defination and basical principle, operative method, clinical outcomes and deficiency of kinematical alignment during total knee arthroplasty, in order to choose a better way for kinematical alignment during total knee arthroplasty. PMID:26911130

  10. [The ACL tear from the pre-operative analysis to a 2-year follow-up, influence of the graft choice on the subjective and objective evaluation].

    PubMed

    Dejour, D; Potel, J-F; Gaudot, F; Panisset, J-C; Condouret, J

    2008-12-01

    This study is a synthesis of three series. The first study was prospective on 418 patients with an anterior cruciate ligament (ACL) tear (group I). Two population of ACL ruptures were identified. One population with a postero-lateral bundle preserved in 16%, the mean medial anterior tibial translation side to side was 4.97 mm, the Lachman test was delayed in 40% with no or glide pivot shift in 73%. The second population with a complete ACL tear had a mean medial anterior tibial translation side to side of 7.93 mm, the Lachman test was soft in 98% with gross pivot shift in 80%. The second study was a retrospective study on 258 patients (group II) at 26 months follow-up, it correlated the impact of the type of graft on the clinical objective and subjective results. Twenty-eight percent had anterior knee pain, 33% for the patellar tendon and 25% for the hamstrings, the subjective IKDC was significantly lower for the painful knees, and 68% of the patellar tendon had a hypoesthesia and only 32% for the hamstrings. The ability to walk on the knee was 68% for the hamstrings and 35% for the patellar tendon. The third study was retrospective on 127 patients, 24 months after ACL reconstruction (group III), all were tested on a isokinetic machine for the extensor, the flexor and the internal rotator. In the total population, a 10% extensor and flexor deficit and a 5% rotator deficit was noted. A significant difference between patellar tendon and hamstrings in terms of muscular recovery was found. It pointed out that a more specific rehabilitation should be done on the hamstring group. The muscular recovery was correlated to the highest subjective score. This study allowed the surgeon to be more specific in the ACL tear definition, to adapt the graft choice to the type of sport activity but also to the type of work the patient does and finally to modify the rehabilitation protocol for the hamstring technique. PMID:19046692

  11. Segmentation of anterior cruciate ligament in knee MR images using graph cuts with patient-specific shape constraints and label refinement.

    PubMed

    Lee, Hansang; Hong, Helen; Kim, Junmo

    2014-12-01

    We propose a graph-cut-based segmentation method for the anterior cruciate ligament (ACL) in knee MRI with a novel shape prior and label refinement. As the initial seeds for graph cuts, candidates for the ACL and the background are extracted from knee MRI roughly by means of adaptive thresholding with Gaussian mixture model fitting. The extracted ACL candidate is segmented iteratively by graph cuts with patient-specific shape constraints. Two shape constraints termed fence and neighbor costs are suggested such that the graph cuts prevent any leakage into adjacent regions with similar intensity. The segmented ACL label is refined by means of superpixel classification. Superpixel classification makes the segmented label propagate into missing inhomogeneous regions inside the ACL. In the experiments, the proposed method segmented the ACL with Dice similarity coefficient of 66.47±7.97%, average surface distance of 2.247±0.869, and root mean squared error of 3.538±1.633, which increased the accuracy by 14.8%, 40.3%, and 37.6% from the Boykov model, respectively. PMID:25305694

  12. Persistent Biomechanical Alterations After ACL Reconstruction Are Associated With Early Cartilage Matrix Changes Detected by Quantitative MR

    PubMed Central

    Amano, Keiko; Pedoia, Valentina; Su, Favian; Souza, Richard B.; Li, Xiaojuan; Ma, C. Benjamin

    2016-01-01

    Background: The effectiveness of anterior cruciate ligament (ACL) reconstruction in preventing early osteoarthritis is debated. Restoring the original biomechanics may potentially prevent degeneration, but apparent pathomechanisms have yet to be described. Newer quantitative magnetic resonance (qMR) imaging techniques, specifically T1ρ and T2, offer novel, noninvasive methods of visualizing and quantifying early cartilage degeneration. Purpose: To determine the tibiofemoral biomechanical alterations before and after ACL reconstruction using magnetic resonance imaging (MRI) and to evaluate the association between biomechanics and cartilage degeneration using T1ρ and T2. Study Design: Cohort study; Level of evidence, 2. Methods: Knee MRIs of 51 individuals (mean age, 29.5 ± 8.4 years) with unilateral ACL injuries were obtained prior to surgery; 19 control subjects (mean age, 30.7 ± 5.3 years) were also scanned. Follow-up MRIs were obtained at 6 months and 1 year. Tibial position (TP), internal tibial rotation (ITR), and T1ρ and T2 were calculated using an in-house Matlab program. Student t tests, repeated measures, and regression models were used to compare differences between injured and uninjured sides, observe longitudinal changes, and evaluate correlations between TP, ITR, and T1ρ and T2. Results: TP was significantly more anterior on the injured side at all time points (P < .001). ITR was significantly increased on the injured side prior to surgery (P = .033). At 1 year, a more anterior TP was associated with elevated T1ρ (P = .002) and T2 (P = .026) in the posterolateral tibia and with decreased T2 in the central lateral femur (P = .048); ITR was associated with increased T1ρ in the posteromedial femur (P = .009). ITR at 6 months was associated with increased T1ρ at 1 year in the posteromedial tibia (P = .029). Conclusion: Persistent biomechanical alterations after ACL reconstruction are related to significant changes in cartilage T1ρ and T2 at 1 year

  13. Accuracy of clinical diagnosis in knee arthroscopy.

    PubMed Central

    Brooks, Stuart; Morgan, Mamdouh

    2002-01-01

    A prospective study of 238 patients was performed in a district general hospital to assess current diagnostic accuracy rates and to ascertain the use and the effectiveness of magnetic resonance imaging (MRI) scanning in reducing the number of negative arthroscopies. The pre-operative diagnosis of patients listed for knee arthroscopy was medial meniscus tear 94 (40%) and osteoarthritis 59 (25%). MRI scans were requested in 57 patients (24%) with medial meniscus tear representing 65% (37 patients). The correlation study was done between pre-operative diagnosis, MRI and arthroscopic diagnosis. Clinical diagnosis was as accurate as the MRI with 79% agreement between the preoperative diagnosis and arthroscopy compared to 77% agreement between MRI scan and arthroscopy. There was no evidence, in this study, that MRI scan can reduce the number of negative arthroscopies. Four normal MRI scans had positive arthroscopic diagnosis (two torn medial meniscus, one torn lateral meniscus and one chondromalacia patella). Out of 240 arthroscopies, there were only 10 normal knees (negative arthroscopy) representing 4% of the total number of knee arthroscopies; one patient of those 10 cases had MRI scan with ACL rupture diagnosis. Images Figure 1 Figure 2 PMID:12215031

  14. Femoral intercondylar notch shape and dimensions in ACL-injured patients.

    PubMed

    van Eck, Carola F; Martins, Cesar A Q; Vyas, Shail M; Celentano, Umberto; van Dijk, C Niek; Fu, Freddie H

    2010-09-01

    The femoral intercondylar notch has been an anatomic site of interest as it houses the anterior cruciate ligament (ACL). The objective of this study was to arthroscopically evaluate the femoral notch in patients with known ACL injury. This evaluation included establishing a classification for notch shapes, identifying the shape frequency, measuring notch dimensions, and determining correlation between notch shape, notch dimensions, and demographic patient data. In this clinical cohort study, 102 consecutive patients underwent diagnostic arthroscopic evaluation of the notch. Several intra-operative photos, videos, and measurements were taken of the notch. Demographic data for each patient were recorded including age, gender, height, weight, and BMI. Three categories of notch shape were established: 1. A-shaped; 2. U-shaped; and 3. W-shaped. Two blinded independent orthopedic surgeons were asked to categorize the recorded notches. Notch shape, dimensions, and demographic factors were correlated. Of the 102 notches evaluated, 55 notches were found to be "A-shaped," 42 "U-shaped," and 5 "W-shaped." "A-shaped" notches were narrower in all width dimensions than "U-shaped" notches. Only patient height was found to influence notch shape with a positive association between taller patients and "U-shaped" and "W-shaped" notches (P = 0.011). Women had a smaller notch width at the base and middle of the notch. With this data, surgeons who enter the knee and appreciate an "A-shaped" notch should consider placing the arthroscope in the anteromedial portal and drill the femoral tunnel through an accessory medial portal to improve visualization and accuracy in anatomic femoral tunnel creation. PMID:20390246

  15. Injuries to the posterior cruciate ligament of the knee.

    PubMed

    Kannus, P; Bergfeld, J; Järvinen, M; Johnson, R J; Pope, M; Renström, P; Yasuda, K

    1991-08-01

    The posterior cruciate ligament (PCL) is the strongest ligament about the knee and is approximately twice as strong as the anterior cruciate ligament. Its main function is to prevent the posterior dislocation of the tibia in relation to the femur, providing 95% of the strength to resist the tibial posterior displacement. Along with the anterior cruciate ligament (ACL) the PCL controls the passive 'screw home' mechanism of the knee in terminal knee extension. It also provides mechanical support for the collateral ligaments during valgus or varus stress of the knee. PCL ruptures are uncommon apparently due to its strong fibre structure. The most frequent injury mechanism in isolated PCL tears is a direct blow on the anterior tibia with the knee flexed thus driving the tibia posteriorly. Automobile accidents (in which the knee hits the dashboard) and soccer injuries (in which an athlete receives a blow to the anterior surface of the tibia during knee flexion) characteristically produce this type of injury. In other PCL injury mechanisms (hyperextension, hyperflexion or rotational injuries with associated valgum/varum stress), other knee structures are also often damaged. The most characteristic diagnostic finding in a knee with a PCL rupture is the 'posterior sag sign' meaning the apparent disappearance of the tibial tubercle in lateral inspection when the knee is flexed 90 degrees. This is due to gravity-assisted posterior displacement of the tibia in relation to the femur. A positive posterior drawer test performed at 90 degrees of flexion and a knee hyperextension sign are sensitive but nonspecific tests. False negative findings are frequent, especially in acute cases. If necessary, the clinical diagnosis of the PCL tear can be verified by magnetic resonance imaging, examination under anaesthesia, arthroscopy, or a combination of these modalities. If a PCL avulsion fragment has been dislocated, surgical treatment is recommended. In isolated, complete midsubstance

  16. Combined Anterior and Anterolateral Stabilization of the Knee With the Iliotibial Band.

    PubMed

    Lutz, Christian; Sonnery-Cottet, Bertrand; Imbert, Pierre; Barbosa, Nuno Camelo; Tuteja, Sanesh; Jaeger, Jean-Henri

    2016-04-01

    Interest and knowledge on the anatomy, function, and biomechanical properties of the anterolateral ligament has led to the recognition of the importance of this structure in rotational control of the knee. This article describes a technique that allows for a combined anterior cruciate ligament (ACL) and anterolateral reconstruction, using an Iliotibial band (ITB) autograft. The graft is detached from the vastus lateralis from proximal to distal, at the center portion from ITB, preserving its distal insertion on the Gerdy tubercle. Its width is 1 cm for the distal part, used for the anterolateral ligament reconstruction, and 3 cm for the proximal part. An outside-in femoral tunnel is drilled respecting both the preferred favorable isometric femoral insertion site and the femoral ACL footprint. An ACL reconstruction combined with a lateral tenodesis with a continuous ITB graft respects the anatomical and isometric rules providing superior internal rotational control of the knee in comparison with a stand-alone ACL reconstruction. PMID:27354943

  17. Histological Predictors of Maximum Failure Loads Differ Between the Healing ACL and ACL Grafts After 6 and 12 Months In Vivo

    PubMed Central

    Proffen, Benedikt L.; Fleming, Braden C.; Murray, Martha M.

    2013-01-01

    Background: Bioenhanced anterior cruciate ligament (ACL) repair, where the suture repair is supplemented with a biological scaffold, is a promising novel technique to stimulate healing after ACL rupture. However, the histological properties of a successfully healing ACL and how they relate to the mechanical properties have not been fully described. Purpose: To determine which histological features best correlate with the mechanical properties of the healing ACL repairs and ACL grafts in a porcine model at 6 and 12 months after injury. Study Design: Controlled laboratory study. Methods: A total of 48 Yucatan mini-pigs underwent ACL transection followed by: (1) conventional ACL reconstruction with bone–patellar tendon–bone (BPTB) allograft, (2) bioenhanced ACL reconstruction with BPTB allograft using a bioactive scaffold, or (3) bioenhanced ACL repair using the same bioactive scaffold. After 6 and 12 months of healing, structural properties of the ACL or graft (yield and failure load, linear stiffness) were measured. Following mechanical testing, ACL specimens were histologically analyzed for cell and vascular density and qualitatively assessed using the advanced Ligament Maturity Index. Results: After 6 months of healing, the cellular organization subscore was most predictive of yield load (r 2 = 0.98), maximum load (r 2 = 0.89), and linear stiffness (r 2 = 0.95) of the healing ACL, while at 12 months, the collagen subscore (r 2 = 0.68) became the best predictor of maximum load. For ACL grafts, the reverse was true, with the collagen subscore predictive of yield and maximum loads at 6 months (r 2 = 0.55) and graft cellularity predictive of maximum load of the graft at 12 months (r 2 = 0.50). Conclusion: These findings suggest there may be key biological differences in development and maintenance of ACL tissue after repair or reconstruction, with early ligament function dependent on cellular population of the repair but early graft function dependent on the

  18. Patient Perception of Reimbursement for Arthroscopic Meniscectomy and ACL Reconstruction

    PubMed Central

    Okoroha, Kelechi; Keller, Robert A.; Marshall, Nathan E.; Guest, John-Michael; Lynch, Jonathan; Lock, Terrence R.; Rill, Brian K.

    2016-01-01

    Objectives: Healthcare policy changes and decreases in Medicare physician reimbursement continue to change the landscape of healthcare. Historically, patient perceptions of surgeon reimbursement have been exaggerated compared to actual reimbursement. Currently there is limited evidence for patient perception for arthroscopic meniscectomy and ACL reconstruction. The purpose of this study was to evaluate patient perception of physician reimbursement for arthroscopic meniscectomy and ACL reconstruction and to compare health care perceptions between urban and suburban clinics. Methods: Surveys were given to 231 consecutive patients, 127 in an urban clinic and 104 in a suburban clinic. Patients were asked their estimation of reasonable reimbursement for arthroscopic meniscectomy and ACL reconstruction as well as their perception on actual Medicare reimbursement to physicians. They were also asked how much would they be willing to pay out of pocket for the procedures. After revealing actual reimbursement rates, patients were asked if reimbursement levels were appropriate, whether surgeon subspecialty training was important, and if additional compensation should be associated with subspecialty training. Survey responses were compared with respondents in an urban versus a suburban setting as well as amongst income and education level. Results: Patients on average reported surgeons should receive $8,096 for a meniscectomy and $11,794 for an ACL reconstruction, 14 times and 11 times as much as actually reimbursed, respectively. Patients estimated that Medicare paid physicians $5,442 for a meniscectomy and $6,667 for an ACL reconstruction. Patients were willing to pay $2,286 out of pocket for a meniscectomy and $11,793 for an ACL reconstruction. Sixty five percent of patients believed reimbursement for meniscectomy was too low and 57% of patients believe reimbursement for ACL reconstruction was too low. Less than 2% of patients believed physician salaries should be cut

  19. What Are Knee Problems?

    MedlinePlus

    ... sprain." The ACL is most often stretched or torn (or both) by a sudden twisting motion. The ... tendinitis (inflammation of a tendon) to a ruptured (torn) tendon. Torn tendons most often occur from: Overusing ...

  20. A tale of 10 European centres – 2010 APOSSM travelling fellowship review in ACL surgery

    PubMed Central

    2012-01-01

    The purpose of ESSKA- APOSSM Travelling fellowship is to better understand the epidemiology, management and surgical techniques for sports across continents. There has been a progressive evolution in ACL reconstruction and there is variation in technique in ACL reconstruction amongst the most experienced surgeons in different continents. During this one month fellowship, we saw various ACL reconstruction techniques using different graft sources, with a variety of graft fixation methods, with the common aim of recreating an anatomical ACL reconstruction. PMID:22839644

  1. A Rare Combination of Avulsion Fractures Around the Knee –A Case Report

    PubMed Central

    Reddy, Hanumantha; Thonse, Chirag; Chikkanna, Jayanth Kumar Bangalore

    2015-01-01

    Patella fractures, tibial spine avulsion and Segond fractures are mainly due to trauma to the knee which may be direct or indirect injuries. While each entity is well documented when occurring in isolation, but bilateral inferior pole patella fracture, tibial spine avulsion in the right knee and bilateral segond fracture in a same patient is a rare occurrence. We report a case of 24-year-old male with such an injury. The diagnosis was confirmed by X-ray, CT scan and MRI imaging of right knee. Then the patient was treated with arthroscopic anterior cruciate ligament (ACL) avulsion fixation with pull through technique and suture disc; bilateral inferior pole patella was treated conservatively with knee brace, segond fracture was treated conservatively similarly. To the best of our knowledge, this is the rare case in the medical literature with all these injuries occurring simultaneously. PMID:26500971

  2. 50 CFR 648.140 - Black sea bass Annual Catch Limit (ACL).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 12 2012-10-01 2012-10-01 false Black sea bass Annual Catch Limit (ACL... Management Measures for the Black Sea Bass Fishery § 648.140 Black sea bass Annual Catch Limit (ACL). (a) The Black Sea Bass Monitoring Committee shall recommend to the MAFMC separate ACLs for the commercial...

  3. 50 CFR 648.140 - Black sea bass Annual Catch Limit (ACL).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Black sea bass Annual Catch Limit (ACL... Management Measures for the Black Sea Bass Fishery § 648.140 Black sea bass Annual Catch Limit (ACL). (a) The Black Sea Bass Monitoring Committee shall recommend to the MAFMC separate ACLs for the commercial...

  4. 50 CFR 648.140 - Black sea bass Annual Catch Limit (ACL).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Black sea bass Annual Catch Limit (ACL... Management Measures for the Black Sea Bass Fishery § 648.140 Black sea bass Annual Catch Limit (ACL). (a) The Black Sea Bass Monitoring Committee shall recommend to the MAFMC separate ACLs for the commercial...

  5. 50 CFR 648.230 - Spiny dogfish Annual Catch Limits (ACLs).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Spiny dogfish Annual Catch Limits (ACLs... Management Measures for the Spiny Dogfish Fishery § 648.230 Spiny dogfish Annual Catch Limits (ACLs). (a) The Spiny Dogfish Monitoring Committee shall recommend to the Joint Spiny Dogfish Committee, an ACL for...

  6. 50 CFR 648.230 - Spiny dogfish Annual Catch Limits (ACLs).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Spiny dogfish Annual Catch Limits (ACLs... Management Measures for the Spiny Dogfish Fishery § 648.230 Spiny dogfish Annual Catch Limits (ACLs). (a) The Spiny Dogfish Monitoring Committee shall recommend to the Joint Spiny Dogfish Committee, an ACL for...

  7. Preventing ACL Injuries in Females: What Physical Educators Need to Know

    ERIC Educational Resources Information Center

    Toscano, Lisa; Carroll, Brianne

    2015-01-01

    Anterior cruciate ligament (ACL) injuries happen at a frequent rate, especially in girls and women. While there are many factors that contribute to ACL tears, teaching proper landing techniques and strengthening certain muscles can decrease the incidence of ACL tears, especially in women. This article reviews some of the high-risk factors that…

  8. Sex differences in knee strength deficit 1 year after anterior cruciate ligament reconstruction

    PubMed Central

    Kim, Do Kyung; Park, Won Hah

    2015-01-01

    [Purpose] Little is known about the outcome differences between men and women after anterior cruciate ligament (ACL) reconstruction. Therefore, the present study aimed to compare knee muscle strength between men and women 1 year after ACL reconstruction. [Subjects and Methods] Retrospective and outcome study. Between 2012 and 2015, 35 males (mean age, 29.7 ± 010.7 years) and 35 females (mean age, 28.2 ± 11.3 years) who had undergone primary ACL reconstruction were recruited from Samsung medical centers. We assessed the strength deficit in the quadriceps (extensor) and hamstrings (flexor) at 60°/sec and 180°/sec with isokinetic testing equipment. Statistical analysis was conducted with a t-test to determine if sex differences existed in knee strength deficit. [Results] Significant differences were noted between men and women with respect to extensor muscle strength deficit. Women reported less extensor muscle strength than men did, at the angular velocities 60°/sec and 180°/sec. However, no significant sex differences were found at either velocity with respect to the strength deficit of the knee flexor muscles. [Conclusion] Compared to male patients, female patients reported significantly less extensor muscle strength and less improvement 1 year after reconstruction. PMID:26834366

  9. Potential for Non-Contact ACL Injury Between Step-Close-Jump and Hop-Jump Tasks

    PubMed Central

    Wang, Li-I; Gu, Chin-Yi; Chen, Wei-Ling; Chang, Mu-San

    2010-01-01

    This study aimed to compare the kinematics and kinetics during the landing of hop-jump and step-close-jump movements in order to provide further inferring that the potential risk of ACL injuries. Eleven elite male volleyball players were recruited to perform hop-jump and step-close-jump tasks. Lower extremity kinematics and ground reaction forces during landing in stop-jump tasks were recorded. Lower extremity kinetics was calculated by using an inverse dynamic process. Step-close-jump tasks demonstrated smaller peak proximal tibia anterior shear forces during the landing phase. In step-close-jump tasks, increasing hip joint angular velocity during initial foot-ground contact decreased peak posterior ground reaction force during the landing phase, which theoretically could reduce the risk of ACL injury. Key points The different landing techniques required for these two stop-jump tasks do not necessarily affect the jump height. Hop-jump decreased the hip joint angular velocity at initial foot contact with ground, which could lead to an increasing peak posterior GRF during the landing phase. Hop-jump decreased hip and knee joint angular flexion displacement during the landing, which could increase the peak vertical loading rate during the landing phase. PMID:24149397

  10. Effect of ACL Graft Type on Side-Step Cutting in Young Athletes

    PubMed Central

    Pace, James Lee; Mueske, Nicole; Padilla, Ricardo A.; Katzel, Mia; Healy, Bitte S.; Wren, Tishya

    2016-01-01

    Objectives: Due to the slightly higher re-tear rate for ACL reconstruction (ACLR) with hamstring (HT) versus patellar tendon (PT), differences in movement strategies were assessed during side-step cutting in young athletes with recent ACLR to determine if graft type affected post-operative motion. Methods: Dominant limbs from 21 athletes without lower extremity injury or previous surgery (age 14.9 ± 2.0 years) and 26 limbs with recent (5.1-8.0 months post-operative) unilateral ACLR were included, 18 with HT grafts (age 16.6 ± 3.7 years) and 8 with PT (age 16.7 ± 1.2 years). Lower extremity 3-dimensional data was recorded during the deceleration phase (initial contact to maximum knee flexion) of a 45° cut. Group differences were assessed using analysis of variance with Bonferroni post-hoc tests. Results: The HT group had a slower approach velocity than controls (2.9 vs. 3.5 m/s; p=0.006) with intermediate velocity in the PT group (3.2 m/s). Both the HT and PT groups had lower peak ground reaction force (GRF) compared to controls (HT: 2.0 body weights, PT: 2.2 BW, Control: 2.8 BW; p≤0.02), along with lower peak knee flexion moments (HT: 1.4 Nm/kg, PT: 1.3 Nm/kg, Control: 2.2 Nm/kg; p=0.002). The PT group had less power absorption at the knee than controls (0.3 vs. 0.7 Nm/kg; p=0.07), while the HT group had more at the hip (0.4 vs. 0.1 Nm/kg; p=0.04). The HT group also had higher peak hip flexion (HT: 65.8°, PT: 53.9°, Control: 55.1°; p≤0.06) and hip sagittal plane excursion (HT: 9.4°, PT: 3.6°, Control: 2.8°; p≤0.05) than the PT and control groups. The HT group had lower peak knee valgus moments than controls (0.05 vs. 1.2 Nm/kg; p=0.01) as well as a greater range of frontal plane pelvic (8.2° vs. 3.4°; p=0.03) and hip (7.6° vs. 3.0°; p=0.05) motion. The PT group had intermediate values for valgus moment (0.8 Nm/kg) and pelvic (4.9°) and hip (3.3°) excursion. Conclusion: While both ACLR groups showed reduced GRFs and knee flexion moments

  11. A Novel Methodology for the Simulation of Athletic Tasks on Cadaveric Knee Joints with Respect to In Vivo Kinematics.

    PubMed

    Bates, Nathaniel A; Nesbitt, Rebecca J; Shearn, Jason T; Myer, Gregory D; Hewett, Timothy E

    2015-10-01

    Six degree of freedom (6-DOF) robotic manipulators have simulated clinical tests and gait on cadaveric knees to examine knee biomechanics. However, these activities do not necessarily emulate the kinematics and kinetics that lead to anterior cruciate ligament (ACL) rupture. The purpose of this study was to determine the techniques needed to derive reproducible, in vitro simulations from in vivo skin-marker kinematics recorded during simulated athletic tasks. Input of raw, in vivo, skin-marker-derived motion capture kinematics consistently resulted in specimen failure. The protocol described in this study developed an in-depth methodology to adapt in vivo kinematic recordings into 6-DOF knee motion simulations for drop vertical jumps and sidestep cutting. Our simulation method repeatably produced kinetics consistent with vertical ground reaction patterns while preserving specimen integrity. Athletic task simulation represents an advancement that allows investigators to examine ACL-intact and graft biomechanics during motions that generate greater kinetics, and the athletic tasks are more representative of documented cases of ligament rupture. Establishment of baseline functional mechanics within the knee joint during athletic tasks will serve to advance the prevention, repair and rehabilitation of ACL injuries. PMID:25869454

  12. Individuality of Item Interpretation in Interchangeable ACL Scales

    ERIC Educational Resources Information Center

    Fiske, Donald W.; Barack, Leonard I.

    1976-01-01

    The diversity among interpretations of single items in personality questionnaires has been noted previously. Using adjectives from the Adjective Check List (ACL), the study sought evidence bearing on these questions: Does such diversity make the responses to an item not comparable across subjects? If so, what are the implications for scores based…

  13. The Humanities in the Schools. ACLS Occasion Paper, No. 20.

    ERIC Educational Resources Information Center

    American Council of Learned Societies, New York, NY.

    Designed to serve as a record of the initial public activity of the American Council of Learned Societies (ACLS) Program in Humanities Curriculum Development, this collection of three articles offers different perspectives on the humanities in the schools. In the first article, "The Humanities and Public Education," Stanley N. Katz discusses the…

  14. The ACLS Survey of Scholars: Views on Publications, Computers, Libraries.

    ERIC Educational Resources Information Center

    Morton, Herbert C.; Price, Anne Jamieson

    1986-01-01

    Reviews results of a survey by the American Council of Learned Societies (ACLS) of 3,835 scholars in the humanities and social sciences who are working both in colleges and universities and outside the academic community. Areas highlighted include professional reading, authorship patterns, computer use, and library use. (LRW)

  15. The effect of a novel movement strategy in decreasing ACL risk factors in female adolescent soccer players

    PubMed Central

    Celebrini, Richard G.; Eng, Janice J.; Miller, William C.; Ekegren, Christina L.; Johnston, James D.; MacIntyre, Donna L.

    2015-01-01

    There is a need to investigate the effect of specific movement strategies in reducing biomechanical risk factors for ACL injury in young female athletes. The purpose of this study was 1) to determine the feasibility of implementing a novel movement strategy (Core-PAC) into a team warm-up prior to soccer training based on subject compliance and integration of the Core-PAC into the warm-up and 2) to determine whether the Core-PAC would improve peak knee flexion angles and peak abduction moments at the knee during a side-cut (SC) and an unanticipated side-cut (USC) prior to kicking a soccer ball, and a side-hop (SH) task after immediate instruction and after a four-week training program. A convenience sample of ten 14–16 year old female soccer players were instructed in the Core-PAC immediately after baseline testing and during a training program consisting of a 20-minute warm-up, two-times per week. The Core-PAC was understood and accepted by the subjects and incorporated into their warm-up activities with good compliance. After the immediate instruction, there were significant increases in peak knee flexion angles of a mean 6.4° during the SC (p = 0.001), 3.5° during the USC (p = 0.007), and 5.8° during the SH (p < 0.001) tasks. Peak knee abduction moments decreased by a mean of 0.25 Nm/kg during the SC (p < 0.03), 0.17 Nm/kg during the USC (p = 0.05), and 0.27 Nm/kg during the SH (p = 0.04) tasks. After the 4-week training program, some individuals showed improvement. The results of this study suggest that the Core-PAC may be one method of modifying high-risk movements for ACL injury such as side-cutting and single-leg landing. PMID:22210470

  16. Knee arthroscopy - slideshow

    MedlinePlus

    ... this page: //medlineplus.gov/ency/presentations/100117.htm Knee arthroscopy - series To use the sharing features on ... 5 out of 5 Normal anatomy Overview The knee is a complex joint made up of the ...

  17. Knee braces - unloading

    MedlinePlus

    ... most people talk about the arthritis in their knees, they are referring to a type of arthritis ... is caused by wear and tear inside your knee joints. Cartilage, the firm, rubbery tissue that cushions ...

  18. Partial knee replacement - slideshow

    MedlinePlus

    ... page: //medlineplus.gov/ency/presentations/100225.htm Partial knee replacement - series To use the sharing features on ... A.M. Editorial team. Related MedlinePlus Health Topics Knee Replacement A.D.A.M., Inc. is accredited ...

  19. Osteotomy of the knee

    MedlinePlus

    ... is not affected unless you have had a knee injury in the past. Osteotomy surgery works by shifting ... M. Editorial team. Related MedlinePlus Health Topics Arthritis Knee Injuries and Disorders Browse the Encyclopedia A.D.A. ...

  20. Knee joint replacement

    MedlinePlus

    The results of a total knee replacement are often excellent. The operation relieves pain for most people. Most people do not need help walking after they fully recover. Most artificial knee joints last 10 ...

  1. Partial knee replacement

    MedlinePlus

    Most people recover quickly and have much less pain than they did before surgery. People who have a partial knee replacement recover faster than those who have a total knee replacement. Many people are able to walk ...

  2. Knee joint replacement - slideshow

    MedlinePlus

    ... page: //medlineplus.gov/ency/presentations/100088.htm Knee joint replacement - series—Normal anatomy To use the sharing ... of 4 Overview The knee is a complex joint. It contains the distal end of the femur ( ...

  3. Preoperative predictors for noncopers to pass return to sports criteria after ACL reconstruction.

    PubMed

    Hartigan, Erin H; Zeni, Joseph; Di Stasi, Stephanie; Axe, Michael J; Snyder-Mackler, Lynn

    2012-08-01

    Less than 50% of athletes pass criteria to return to sports (RTS) 6 months after ACL reconstruction (ACLR). Using data on 38 noncopers, we hypothesized that preoperative age, quadriceps strength index (QI), and knee flexion moments (KFM) during gait would predict the ability to pass/fail RTS criteria and that preoperative quadriceps strength gains would be predictive of passing RTS criteria. Gait analysis and strength data were collected before and after a preoperative intervention and 6 months after ACLR. Age, QI, and KFM each contributed to the predictability to pass or fail RTS criteria 6 months after ACLR. Collectively, the variables predict 69% who would pass and 82% who would fail RTS criteria 6 months after ACLR. Younger athletes who have symmetrical quadriceps strength and greater KFM were more likely to pass RTS criteria. Further, 63% of those who increased preoperative quadriceps strength passed RTS criteria, whereas 73% who did not failed. Increasing quadriceps strength in noncopers before ACLR seems warranted. PMID:22983930

  4. Association of the type of trauma, occurrence of bone bruise, fracture and joint effusion with the injury to the menisci and ligaments in MRI of knee trauma

    PubMed Central

    Pezeshki, Sina; Vogl, Thomas J.; Pezeshki, Mohammad Zakaria; Daghighi, Mohammad Hossein; Pourisa, Masoud

    2016-01-01

    Summary Background magnetic resonance imaging (MRI) as a noninvasive diagnostic tool may help clinicians in the evaluation of injuries to menisci and ligaments. Purpose this study assessed the associations between type of trauma to knee joint, bone bruise, fracture and pathological joint effusion with injuries to menisci and ligaments of knee joint. Methods we reviewed knee joint MRI of 175 patients aged less than 45 years old who were referred to MRI center of our University. Results statistical analysis showed that tearing of medial meniscus (MM) is significantly more common in sport related trauma (p= 0.045) but tearing of medial collateral ligament (MCL) is significantly more common in non-sport related trauma (p= 0.005). Existence of bone bruise in knee MRI is negatively associated with tearing of medial meniscus (MM) (p=0.004) and positively associated with tearing of anterior cruciate ligament (ACL) (p=0.00047) and medial collateral ligament (MCL) (p = 0.0001). Existence of fracture is associated with decreased risk of the tearing of ACL and MM (p=0.04, p=0.001 respectively). Pathologic joint effusion is significantly more common in ACL and MCL tearing (p=0.0001, p=0.004 respectively). Conclusions as diagnostic clues, bone bruise, fracture and joint effusion may help radiologists for better assessment of injury to menisci and ligaments in MRI of patients with knee trauma. PMID:27331046

  5. Do Newer-Generation Bioabsorbable Screws Become Incorporated into Bone at Two Years After ACL Reconstruction with Patellar Tendon Graft?

    PubMed Central

    Cox, Charles L.; Spindler, Kurt P.; Leonard, James P.; Morris, Brent J.; Dunn, Warren R.; Reinke, Emily K.

    2014-01-01

    Background: Bioabsorbable interference screws are used frequently for graft fixation in ACL (anterior cruciate ligament) reconstruction. The resorption properties of many available screws that are marketed as bioabsorbable are not well defined. The CALAXO (Smith & Nephew Endoscopy) and MILAGRO (DePuy Synthes) bioabsorbable screws contain polymers of poly(lactic-co-glycolic acid) (PLGA) plus additives to encourage osseointegration over time. The purpose of this study was to evaluate radiographic and magnetic resonance imaging (MRI) properties and compare patient-reported outcomes at a minimum of two years of follow-up after ACL reconstruction using CALAXO or MILAGRO bioabsorbable interference screws. Methods: A cohort of patients who underwent ACL reconstruction in which the fixation used was either CALAXO or MILAGRO screws returned for repeat radiographs for evaluation of tunnel widening, repeat MRI for evaluation of graft integrity and screw breakdown, and completion of the pain and symptom items of the KOOS (Knee injury and Osteoarthritis Outcome Score) questionnaire. Results: At a mean of three years (range, 2.5 to 4.0 years) after surgery, thirty-one patients with sixty-two CALAXO screws and thirty-six patients with seventy-two MILAGRO screws returned for repeat evaluation. Two blinded, independent reviewers found no significant differences between the two screw types when comparing radiographs for tibial or femoral tunnel widening or MRIs for graft integrity, tibial and femoral foreign body reactions, or femoral screw degradation. Both reviewers found a significant difference between the two screw types when comparing tibial screw degradation properties (p < 0.01). All analyzed CALAXO screws were rated as partially intact or degraded; the MILAGRO screws were more likely to be rated as intact. No significant differences were noted between the two screw types when comparing the two KOOS subscales. Conclusions: CALAXO screws in the tibial tunnel were more likely

  6. The Dedicated Chaperone Acl4 Escorts Ribosomal Protein Rpl4 to Its Nuclear Pre-60S Assembly Site

    PubMed Central

    Pillet, Benjamin; García-Gómez, Juan J.; Pausch, Patrick; Falquet, Laurent; Bange, Gert; de la Cruz, Jesús; Kressler, Dieter

    2015-01-01

    Ribosomes are the highly complex macromolecular assemblies dedicated to the synthesis of all cellular proteins from mRNA templates. The main principles underlying the making of ribosomes are conserved across eukaryotic organisms and this process has been studied in most detail in the yeast Saccharomyces cerevisiae. Yeast ribosomes are composed of four ribosomal RNAs (rRNAs) and 79 ribosomal proteins (r-proteins). Most r-proteins need to be transported from the cytoplasm to the nucleus where they get incorporated into the evolving pre-ribosomal particles. Due to the high abundance and difficult physicochemical properties of r-proteins, their correct folding and fail-safe targeting to the assembly site depends largely on general, as well as highly specialized, chaperone and transport systems. Many r-proteins contain universally conserved or eukaryote-specific internal loops and/or terminal extensions, which were shown to mediate their nuclear targeting and association with dedicated chaperones in a growing number of cases. The 60S r-protein Rpl4 is particularly interesting since it harbours a conserved long internal loop and a prominent C-terminal eukaryote-specific extension. Here we show that both the long internal loop and the C-terminal eukaryote-specific extension are strictly required for the functionality of Rpl4. While Rpl4 contains at least five distinct nuclear localization signals (NLS), the C-terminal part of the long internal loop associates with a specific binding partner, termed Acl4. Absence of Acl4 confers a severe slow-growth phenotype and a deficiency in the production of 60S subunits. Genetic and biochemical evidence indicates that Acl4 can be considered as a dedicated chaperone of Rpl4. Notably, Acl4 localizes to both the cytoplasm and nucleus and it has the capacity to capture nascent Rpl4 in a co-translational manner. Taken together, our findings indicate that the dedicated chaperone Acl4 accompanies Rpl4 from the cytoplasm to its pre-60S

  7. The Dedicated Chaperone Acl4 Escorts Ribosomal Protein Rpl4 to Its Nuclear Pre-60S Assembly Site.

    PubMed

    Pillet, Benjamin; García-Gómez, Juan J; Pausch, Patrick; Falquet, Laurent; Bange, Gert; de la Cruz, Jesús; Kressler, Dieter

    2015-10-01

    Ribosomes are the highly complex macromolecular assemblies dedicated to the synthesis of all cellular proteins from mRNA templates. The main principles underlying the making of ribosomes are conserved across eukaryotic organisms and this process has been studied in most detail in the yeast Saccharomyces cerevisiae. Yeast ribosomes are composed of four ribosomal RNAs (rRNAs) and 79 ribosomal proteins (r-proteins). Most r-proteins need to be transported from the cytoplasm to the nucleus where they get incorporated into the evolving pre-ribosomal particles. Due to the high abundance and difficult physicochemical properties of r-proteins, their correct folding and fail-safe targeting to the assembly site depends largely on general, as well as highly specialized, chaperone and transport systems. Many r-proteins contain universally conserved or eukaryote-specific internal loops and/or terminal extensions, which were shown to mediate their nuclear targeting and association with dedicated chaperones in a growing number of cases. The 60S r-protein Rpl4 is particularly interesting since it harbours a conserved long internal loop and a prominent C-terminal eukaryote-specific extension. Here we show that both the long internal loop and the C-terminal eukaryote-specific extension are strictly required for the functionality of Rpl4. While Rpl4 contains at least five distinct nuclear localization signals (NLS), the C-terminal part of the long internal loop associates with a specific binding partner, termed Acl4. Absence of Acl4 confers a severe slow-growth phenotype and a deficiency in the production of 60S subunits. Genetic and biochemical evidence indicates that Acl4 can be considered as a dedicated chaperone of Rpl4. Notably, Acl4 localizes to both the cytoplasm and nucleus and it has the capacity to capture nascent Rpl4 in a co-translational manner. Taken together, our findings indicate that the dedicated chaperone Acl4 accompanies Rpl4 from the cytoplasm to its pre-60S

  8. Knee braces - unloading

    MedlinePlus

    ... is caused by wear and tear inside your knee joints. Cartilage, the firm, rubbery tissue that cushions all of your bones and joints, lets the bones glide over one another. If ... the knee become weaker. Over time, your whole knee becomes ...

  9. Evaluation of strength muscle recovery with isokinetic, squat jump and stiffness tests in athletes with ACL reconstruction: a case control study.

    PubMed

    Jacopetti, Marco; Pasquini, Andrea; Costantino, Cosimo

    2016-01-01

    BackgroundThe anterior cruciate ligament (ACL) rupture accounting for about 50% of all knee ligament injuries. The rehabilitation program requires a long time to rebuild muscle strength and to reestablish joint mobility and neuromuscular control. The purpose of the study is to evaluate the muscle strength recovery in athletes with ACL reconstruction. MethodsWe enrolled soccer atlethes, with isolated anterior cruciate ligament rupture treated with bone-patellar tendon-bone autograft artroscopic reconstruction. Each patients were evaluated comparing operated and controlateral limb by isokinetic test and triaxial accelerometer test. Isokinetic movements tested were knee flexion-extension with concentric-concentric contraction. Accelerometer test were Squat Jump Test (SJT)  and Stiffness Test (ST). Results17 subjects were selected, there was no significant difference in isokinetic quadriceps and hamstrings results in strength and endurance values. Parameters of ST were comparable between the operated and unoperated side. In SJT a significant statistical difference was in height of jump (p=0,02) no statistical difference was evidenced in the other measures.ConclusionCurrently complete recovery of symmetric explosive strength seems to be an important parameter for evaluating the performance after ACL reconstruction and the symmetry in test results jump could be associated with an adequate return to sports. In our study the explosive strenght is lower in the limb operated than the healthy one. Explosive strength recovery with pliometric training should be included in the post-surgical rehabilitation protocol and its measurement should be performed to assess the full recovery before the restart of sport activities. PMID:27163899

  10. The application of musculoskeletal modeling to investigate gender bias in non-contact ACL injury rate during single-leg landings.

    PubMed

    Ali, Nicholas; Andersen, Michael Skipper; Rasmussen, John; Robertson, D Gordon E; Rouhi, Gholamreza

    2014-01-01

    The central tenet of this study was to develop, validate and apply various individualised 3D musculoskeletal models of the human body for application to single-leg landings over increasing vertical heights and horizontal distances. While contributing to an understanding of whether gender differences explain the higher rate of non-contact anterior cruciate ligament (ACL) injuries among females, this study also correlated various musculoskeletal variables significantly impacted by gender, height and/or distance and their interactions with two ACL injury-risk predictor variables; peak vertical ground reaction force (VGRF) and peak proximal tibia anterior shear force (PTASF). Kinematic, kinetic and electromyography data of three male and three female subjects were measured. Results revealed no significant gender differences in the musculoskeletal variables tested except peak VGRF (p = 0.039) and hip axial compressive force (p = 0.032). The quadriceps and the gastrocnemius muscle forces had significant correlations with peak PTASF (r = 0.85, p < 0.05 and r = - 0.88, p < 0.05, respectively). Furthermore, hamstring muscle force was significantly correlated with peak VGRF (r = - 0.90, p < 0.05). The ankle flexion angle was significantly correlated with peak PTASF (r = - 0.82, p < 0.05). Our findings indicate that compared to males, females did not exhibit significantly different muscle forces, or ankle, knee and hip flexion angles during single-leg landings that would explain the gender bias in non-contact ACL injury rate. Our results also suggest that higher quadriceps muscle force increases the risk, while higher hamstring and gastrocnemius muscle forces as well as ankle flexion angle reduce the risk of non-contact ACL injury. PMID:23387967

  11. Impact response and biomechanical analysis of the knee-thigh-hip complex in frontal impacts with a full human body finite element model.

    PubMed

    Ruan, Jesse S; El-Jawahri, Raed; Barbat, Saeed; Rouhana, Stephen W; Prasad, Priya

    2008-11-01

    Changes in vehicle safety design technology and the increasing use of seat-belts and airbag restraint systems have gradually changed the relative proportion of lower extremity injuries. These changes in real world injuries have renewed interest and the need of further investigation into occupant injury mechanisms and biomechanical impact responses of the knee-thigh-hip complex during frontal impacts. This study uses a detailed finite element model of the human body to simulate occupant knee impacts experienced in frontal crashes. The human body model includes detailed anatomical features of the head, neck, shoulder, chest, thoracic and lumbar spine, abdomen, pelvis, and lower and upper extremities. The material properties used in the model for each anatomic part of the human body were obtained from test data reported in the literature. The human body model used in the current study has been previously validated in frontal and side impacts. It was further validated with cadaver knee-thigh-hip impact tests in the current study. The effects of impactor configuration and flexion angle of the knee on biomechanical impact responses of the knee-thigh-hip complex were studied using the validated human body finite element model. This study showed that the knee flexion angle and the impact direction and shape of the impactors affected the injury outcomes of the knee-thigh-hip complex significantly. The 60 degrees flexed knee impact showed the least impact force, knee pressure, femoral von Mises stress, and pelvic von Mises stress but largest relative displacements of the Posterior Cruciate Ligament (PCL) and Anterior Cruciate Ligament (ACL). The 90 degrees flexed knee impact resulted in a higher impact force, knee pressure, femoral von Mises stress, and pelvic von Mises stress; but smaller PCL and ACL displacements. Stress distributions of the patella, femur, and pelvis were also given for all the simulated conditions. PMID:19085174

  12. Reducing knee and anterior cruciate ligament injuries among female athletes: a systematic review of neuromuscular training interventions.

    PubMed

    Hewett, Timothy E; Myer, Gregory D; Ford, Kevin R

    2005-01-01

    There is evidence that neuromuscular training not only decreases the potential biomechanical risk factors for ACL injury, but also decreases knee and, specifically, ACL injury incidence in female athletes. Five of the six interventions in this systematic review demonstrated significant effects on overall knee or ACL injury rates. It appears that plyometric power, biomechanics and technique, strength, balance, and core stability training can induce neuromuscular changes and potential injury prevention effects in female athletes. However, it is unknown which of these components is most effective or whether the effects are combinatorial. Future research should assess the relative efficacy of these interventions alone and in combination to achieve the optimal effect in the most efficient manner possible. Selective combination of neuromuscular training components may provide additive effects, further reducing the risk of ACL injuries in female athletes. Additional research directions include the assessment of relative injury risk using mass neuromuscular screening, the development of more specific injury prevention protocols targeted toward high-risk athletes, and the determination of when these interventions should be implemented. It may be that prepubertal or early pubertal female athletes may have the potential to achieve optimal biomechanical changes and the greatest chance of injury-free sports participation throughout their careers. PMID:15742602

  13. Rehabilitation Predictors of Clinical Outcome following Revision ACL Reconstruction

    PubMed Central

    Wright, Rick W.; Group, Mars

    2016-01-01

    Objectives: Revision ACL reconstruction has been documented to have worse outcomes compared with primary ACL reconstructions. The reasons why remain unknown. The purpose of this study was to determine whether rehabilitation-related factors prescribed at the time of ACL revision reconstruction significantly influence two year outcomes, as well as the incidence of incurring a subsequent re-operation. Our hypothesis was that immediate versus passive, active range of motion (ROM) and weightbearing will result in improved outcomes without incidence of subsequent surgery. Use of postoperative and functional return to sport braces will not improve return to sports function. Methods: Revision ACL reconstruction patients were identified and prospectively enrolled between 2006 and 2011. Data collected included baseline demographics, surgical technique and pathology, prescribed post-op and rehabilitation instructions (ie. timing of weightbearing, timing of passive and active ROM, use of postoperative and return to sport braces) and a series of validated patient reported outcome instruments (IKDC, KOOS, and Marx activity rating score). Patients were followed up for 2 years, and asked to complete the identical set of outcome instruments. Because meniscal repair, meniscal transplants, HTOs, concurrent ligamentous reconstructions, and certain chondral treatments (ie. microfracture, abrasion arthroplasty, mosiacplasty, etc) are known to affect prescribed rehab treatments, patients with these pathologies were excluded from the analyses. Regression analysis was used to control for age, gender, activity level, baseline outcome scores, and the above-mentioned rehabilitation-related variables, in order to assess the risk factors for clinical outcomes 2 years after revision ACL reconstruction. Results: A total of 843 patients met the inclusion criteria and were successfully enrolled. 482 (57%) were males, with a median cohort age of 27 years. Baseline characteristics of the cohort are

  14. BIOMECHANICAL STUDY OF TRANSCORTICAL OR TRANSTRABECULAR BONE FIXATION OF PATELLAR TENDON GRAFT WITH BIOABSORBABLE PINS IN ACL RECONSTRUCTION IN SHEEP

    PubMed Central

    Albano, Mauro Batista; Borges, Paulo César; Namba, Mario Massatomo; da Silva, João Luiz Vieira; de Assis Pereira Filho, Francisco; Filho, Edmar Stieven; Matias, Jorge Eduardo Fouto

    2015-01-01

    Objective: To determine the initial resistance of fixation using the Rigid Fix® system, and compare it with traditional fixation methods using metal interference screws; and to evaluate the resistance of the fixation with the rigid fix system when the rotational position of the bone block is altered in the interior of the femoral tunnel. Methods: forty ovine knee specimens (stifle joints) were submitted to anterior cruciate ligament reconstruction (ACL) using a bone-tendon-bone graft. In twenty specimens, the Rigid Fix method was used; this group was subdivided into two groups: ten knees the pins transfixed only the spongious area of the bone block, and ten for fixation passing through the layer of cortical bone. In the twenty remaining specimens, the graft was fixed with 9mm metal interference screws. Results: comparison of the RIGIDFIX® method with the metal interference screw fixation method did not show any statistically significant differences in terms of maximum load and rigidity; also, there were no statistically significant differences when the rotational position of the bone block was altered inside the femoral tunnel. For these evaluations, a level of significance of p < 0.017 was considered. Conclusion: fixation of the bone-tendon-bone graft with 2 bioabsorbable pines, regardless of the rotational position inside the femoral tunnel, gave a comparable fixation in terms of initial resistance to the metal interference screw, in this experimental model. PMID:27027081

  15. Balance Ability and Proprioception after Single-Bundle, Single-Bundle Augmentation, and Double-Bundle ACL Reconstruction

    PubMed Central

    Ma, Yubao; Iwaki, Daisuke; Asaeda, Makoto; Adachi, Nobuo; Ochi, Mitsuo

    2014-01-01

    Purpose. The present study sought to determine the influences of single-bundle (SB), single-bundle augmentation (SBA), and double-bundle (DB) reconstructions on balance ability and proprioceptive function. Methods. 67 patients who underwent a single- or double-bundle ACL reconstruction or a SBA using multistranded autologous hamstring tendons were included in this study with a 1-year follow-up. Body sway and knee kinesthesia (using the threshold to detect passive motion test (TTDPM)) were measured to indicate balance ability and proprioceptive function, respectively. Additionally, within-subject differences in anterior-posterior stability of the tibia and lower extremity muscle strength were evaluated before and after surgery. Results. At 6 and 12 months after surgery, DB reconstruction resulted in better balance and proprioceptive function than SB reconstruction (P < 0.05). Although no significant difference was observed in balance ability or proprioceptive function between the SBA and DB reconstructions, knee stability was significantly better with SBA and DB reconstructions than SB reconstruction (P < 0.05). No significant differences were found in quadriceps and hamstrings strength among the three reconstruction techniques. Conclusions. Our findings consider that joint stability, proprioceptive function, and balance ability were superior with SBA and DB reconstructions compared to SB reconstruction at 6 and 12 months after surgery. PMID:25614884

  16. Relationship Between Functional Knee Joint Position Sense and Functional Performance Scores Following Anterior Cruciate Ligament Reconstruction (Pilot Study)

    PubMed Central

    Kafa, Nihan; Ataoglu, Muhammed Baybars; Hazar, Zeynep; Citaker, Seyit; Ozer, Mustafa

    2014-01-01

    Objectives: The aim of this study was to assess the relationship between functional knee joint position sense (JPS) and functional performance following ACL reconstruction Methods: Seven male patients (mean age=32,66 ±6,47) who had undergone ACL reconstruction and 10 male healthy control subjects participated in the study. Knee joint position sense was evaluated by reproduction of 20° knee flexion angle in weight-bearing position with single and bilateral limb movement into flexion and extension. The deviations in the angle were recorded and compared to both noninjured side and healthy controls’. Functional performance was evaluated with Single Leg Hop Test in both injured and non-injured sides. The scores were also compared with healthy controls and non-injured sides. Relationship between measured values was tested with Spearman Correlation Analysis. Results: There was no significant difference in knee joint position sense in functional position between the operated and uninjured knees of patients or between patients and healthy controls (p>0,05). However, there is significant difference in Single Leg Hop test scores between operated and non-operated or between patients and healthy controls (p=0,037; p<0,05). There was no significant correlation between Single Leg Hop test scores and knee joint position sense (p>0,05). Conclusion: There was no evidence of impaired joint position sense in weight-bearing positions in subjects with ACL reconstruction but there was a decrease in functional performance. This decrease in functional performance may depend on the other parameters except proprioceptive deficits.

  17. A Hypothesis: Could Portable Natural Grass be a Risk Factor for Knee Injuries?

    PubMed Central

    Orchard, John; Rodas, Gil; Til, Lluis; ArdevÒl, Jordi; Chivers, Ian

    2008-01-01

    Previous study has shown a likely link between increased shoe- surface traction and risk of knee Anterior Cruciate Ligament (ACL) injury. Portable natural grass systems are being used more often in sport, but no study to date has investigated their relative safety. By their nature, they must have high resistance to falling apart and therefore newly laid systems may be at risk of creating excessive shoe-surface traction. This study describes two clusters of knee injuries (particularly non-contact ACL injuries), each occurring to players of one professional football team at single venue, using portable grass, in a short space of time. The first series included two ACL injuries, one posterolateral complex disruption and one lateral ligament tear occurring in two rugby league games on a portable bermudagrass surface in Brisbane, Australia. The second series included four non-contact ACL injuries over a period of ten weeks in professional soccer games on a portable Kentucky bluegrass/perennial ryegrass surface in Barcelona, Spain. Possible intrinsic risk factors are discussed but there was no common risk shared by the players. Although no measures of traction were made at the Brisbane venue, average rotational traction was measured towards the end of the injury cluster at Camp Nou, Barcelona, to be 48 Nm. Chance undoubtedly had a part to play in these clusters, but the only obvious common risk factor was play on a portable natural grass surface soon after it was laid. Further study is required to determine whether portable natural grass systems may exhibit high shoe-surface traction soon after being laid and whether this could be a risk factor for knee injury. Key pointsExcessive shoe-surface traction is a hypothesised risk factor for knee ligament injuries, including anterior cruciate ligament injuries.Portable natural grass systems (by their nature in order to prevent grass rolls or squares from falling apart) will tend to exhibit high resistance to tearing when first

  18. Growth disturbances without growth arrest after ACL reconstruction in children.

    PubMed

    Chotel, Franck; Henry, Julien; Seil, Romain; Chouteau, Julien; Moyen, Bernard; Bérard, Jérôme

    2010-11-01

    Growth arrest is a major concern after ACL reconstruction in children. It usually occurs in patients near to closure of the growth plates. Growth disturbances without growth arrest are also possible and more vicious; the authors analyse the mechanism of two patients with growth disturbance due to overgrowth following ACL reconstruction. One was a symmetrical overgrowth process with 15 mm limb length discrepancy treated with percutaneous epiphysiodesis. Full correction at the time of skeletal maturity was achieved. The second patient developed an asymmetrical overgrowth with progressive tibial valgus deformity. This mechanism was similar to a posttraumatic tibial valgus deformity. After nonoperative treatment, a spontaneous correction of the deformity was noticed. Both children were young (7 and 10 years old) at the time of ACL reconstruction with an autologous iliotibial band graft. The clinical relevance of overgrowth disturbance is usually limited when compared to growth arrest but could require a second surgical procedure as reported in this study. Parents must be informed that even in experienced hands, and despite the use of a physeal sparing technique, this specific risk of growth disturbance is still present. PMID:20182870

  19. Level of constraint in revision knee arthroplasty.

    PubMed

    Indelli, Pier Francesco; Giori, Nick; Maloney, William

    2015-12-01

    Revision total knee arthroplasty (TKA) in the setting of major bone deficiency and/or soft tissue laxity might require increasing levels of constraint to restore knee stability. However, increasing the level of constraint not always correlates with mid-to-long-term satisfactory results. Recently, modular components as tantalum cones and titanium sleeves have been introduced to the market with the goal of obtaining better fixation where bone deficiency is an issue; theoretically, satisfactory meta-diaphyseal fixation can reduce the mechanical stress at the level of the joint line, reducing the need for high levels of constraint. This article reviews the recent literature on the surgical management of the unstable TKA with the goal to propose a modern surgical algorithm for adult reconstruction surgeons. PMID:26373770

  20. Sex Differences in Knee Flexion Angle During a Rapid Change of Direction While Running

    PubMed Central

    Sheu, Christopher L.; Gray, Aaron M.; Brown, David; Smith, Brian A.

    2015-01-01

    Background: Females experience greater overall rates of athletic anterior cruciate ligament (ACL) injury than males. The specific mechanisms of the predisposition remain unclear. Hypothesis: Modeling of knee kinematics has shown that the more extended the knee joint, the greater the strain on the ACL. The authors hypothesized that female athletes would have a lesser degree of knee flexion than male athletes at initial ground contact while performing change-of-direction cutting maneuvers. Study Design: Controlled laboratory study. Methods: Twenty female and 20 male high school soccer athletes with at least 1 year of experience were recruited for the study. Athletes were excluded if they had a history of any major lower limb injury or current knee pain causing a reduction in training and/or competition. Reflective markers were attached at the greater trochanter of the femur, the lateral epicondyle of the knee, and the lateral malleolus of the ankle to enable motion capture. Each athlete performed 6 change-of-direction maneuvers in random order in front of 2 cameras. Multiple regression analysis was used to determine differences between the sexes from the motion data captured; P < .05 defined significance. Results: Statistically significant differences existed in knee flexion angles between male and female participants at the 90° and 135° cutting angles. At 90°, males and females showed initial contact knee flexion angles (mean ± SD) of 39.0° ± 6.8° and 29.3° ± 6.2°, respectively (P < .0001), and mean maximum flexion angles of 56.4° ± 6.9° and 49.7° ± 7.0°, respectively (P = .0036). At 135°, males and females showed mean initial contact knee flexion angles of 36.8° ± 7.9° and 29.7° ± 7.8°, respectively (P = .0053), and mean maximum flexion angles of 60.7° ± 8.1° and 51.6° ± 9.4°, respectively (P = .0017). Conclusion: The research conducted is intended to foster an awareness of injury disposition in female athletes and guide future

  1. Effects of Gaps Induced Into the ACL Tendon Graft on Tendon-Bone Healing in a Rodent ACL Reconstruction Model

    PubMed Central

    Lovric, Vedran; Kanazawa, Tomonoshin; Nakamura, Yoshinari; Oliver, Rema A.; Yu, Yan; Walsh, William Robert

    2011-01-01

    Summary Graft necrosis following ACL reconstruction is often associated with the use of autologous grafts. Host cells rather than graft cells contribute to the repair of the tendon-bone interface and the remodeling of the autologous graft. The native tendon-bone interface is not recreated and the biomechanical properties are not restored back to native values. We examined the effects of introducing gaps within the tendon graft prior to ACL reconstruction in a rodent model. We hypothesised that gaps will make physical way for host cells to infiltrate and repopulate the graft and thus enhance healing. Animals were sacrificed at seven, fourteen, and twenty-eight days for biomechanical testing and histology. Our findings indicate that graft necrosis, usually observed in the initial two weeks of the healing process, is averted. Histological observations showed that tendon-bone healing stages were hastened however this didn’t translate into improved biomechanical properties. PMID:23738254

  2. A dynamic multibody model of the physiological knee to predict internal loads during movement in gravitational field.

    PubMed

    Bersini, Simone; Sansone, Valerio; Frigo, Carlo A

    2016-01-01

    Obtaining tibio-femoral (TF) contact forces, ligament deformations and loads during daily life motor tasks would be useful to better understand the aetiopathogenesis of knee joint diseases or the effects of ligament reconstruction and knee arthroplasty. However, methods to obtain this information are either too simplified or too computationally demanding to be used for clinical application. A multibody dynamic model of the lower limb reproducing knee joint contact surfaces and ligaments was developed on the basis of magnetic resonance imaging. Several clinically relevant conditions were simulated, including resistance to hyperextension, varus-valgus stability, anterior-posterior drawer, loaded squat movement. Quadriceps force, ligament deformations and loads, and TF contact forces were computed. During anterior drawer test the anterior cruciate ligament (ACL) was maximally loaded when the knee was extended (392 N) while the posterior cruciate ligament (PCL) was much more stressed during posterior drawer when the knee was flexed (319 N). The simulated loaded squat revealed that the anterior fibres of ACL become inactive after 60° of flexion in conjunction with PCL anterior bundle activation, while most components of the collateral ligaments exhibit limited length changes. Maximum quadriceps and TF forces achieved 3.2 and 4.2 body weight, respectively. The possibility to easily manage model parameters and the low computational cost of each simulation represent key points of the present project. The obtained results are consistent with in vivo measurements, suggesting that the model can be used to simulate complex and clinically relevant exercises. PMID:26057607

  3. Understanding and preventing acl injuries: current biomechanical and epidemiologic considerations - update 2010.

    PubMed

    Hewett, Timothy E; Ford, Kevin R; Hoogenboom, Barbara J; Myer, Gregory D

    2010-12-01

    This invited clinical commentary summarizes the current state of knowledge in the area of prevention of anterior cruciate ligament (ACL) injuries. ACL injuries occur with a four to six fold greater incidence in female compared to male athletes playing the same high risk sports. The combination of increased risk of ACL injury and a 10-fold increase in sports participation since the enactment of Title IX in 1972 has led to an almost epidemic rise in ACL injuries in female athletes. Examination of the mechanisms responsible for this sex disparity in ACL rupture accelerated in the last two decades. A summary of these findings and a synthesis and framework for understanding the results of the intense investigation of this research are detailed herein. This clinical commentary focuses on the current understanding, identification and interventional targeting of the primary neuromuscular and biomechanical risk factors associated with the ACL injury mechanism in high-risk individuals. PMID:21655382

  4. Comparison of Knee Moments and Landing Patterns During a Lateral Cutting Maneuver: Shod Vs. Barefoot.

    PubMed

    Bisesti, Brianna A; Lawrence, Michael A; Koch, Alexander J; Carlson, Lara A

    2015-11-01

    Noncontact anterior cruciate ligament (ACL) injuries often occur during lateral cutting maneuvers, in which extension, adduction, and external rotation create high loads on the ACL. The aim of this study was to examine knee moments and foot strike patterns during lateral cutting when shod (SD) and barefoot (BF). Fifteen NCAA Division III athletes (7 female and 8 male; age 20.2 ± 1.5 years; mass 71.5 ± 11.3 kg; height, 1.7 ± 0.06 m) without lower limb pathologies were analyzed during 5 trials of 45° lateral cutting maneuvers for each limb in both BF and SD conditions with the approach speed of 4.3 m·s. Kinetic and kinematic data were collected using an 8-camera motion capture system and a force plate with collection rates at 240 Hz and 2400 Hz, respectively. Paired t-tests were used to determine differences conditions. The SD condition produced a significantly (p ≤ 0.05) greater peak adduction moment and cutting, whereas BF caused more anterior foot strike. Lateral cutting when BF places no more stress on the ACL than when SD. Our findings suggest that lateral cutting maneuvers when BF will not increase stress on the ACL. PMID:26506061

  5. 50 CFR 640.28 - Annual catch limits (ACLs) and accountability measures (AMs).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE SPINY LOBSTER FISHERY OF THE GULF... accountability measures (AMs). For recreational and commercial spiny lobster landings combined, the ACL is...

  6. Mechanoreceptors of the ligaments and tendons around the knee.

    PubMed

    Çabuk, Haluk; Kuşku Çabuk, Fatmagül

    2016-09-01

    Proprioceptive inputs from the joints and limbs arise from mechanoreceptors in the muscles, ligaments and tendons. The knee joint has a wide range of movements, and proper neuroanatomical organization is critical for knee stability. Four ligaments (the anterior (ACL) and posterior (PCL) cruciate ligaments and the medial (MCL) and lateral (LCL) collateral ligaments) and four tendons (the semitendinosus (STT), gracilis (GT), popliteal (PoT), and patellar (PaT) tendons) from eight fresh frozen cadavers were harvested. Each harvested tissue was divided into its bone insertion side and its tendinous part for immunohistochemical examination using S100 staining. Freeman-Wyke's classification was used to identify the mechanoreceptors. The mechanoreceptors were usually located close to the bone insertion. Free nerve endings followed by Ruffini endings were the most common mechanoreceptors overall. No Pacini corpuscles were observed; free nerve endings and Golgi-like endings were most frequent in the PCL (PCL-PaT: P = 0.0.1, PCL-STT: P = 0.00), and Ruffini endings in the popliteal tendon (PoT-PaT: P = 0.00, Pot-STT: P = 0.00, PoT-LCL: P = 0.00, PoT-GT: P = 0.00, PoT-ACL: P = 0.09). The cruciate ligaments had more mechanoreceptors than the medial structures (MS) or the patellar tendon (CR-Pat: P = 0.000, CR-MS: P = 0.01). The differences in mechanoreceptor distributions between the ligaments and tendons could reflect the different roles of these structures in the dynamic coordination of knee motion. Clin. Anat. 29:789-795, 2016. © 2016 Wiley Periodicals, Inc. PMID:27376635

  7. Clinical Outcomes of High Tibial Osteotomy for Knee Instability

    PubMed Central

    Dean, Chase S.; Liechti, Daniel J.; Chahla, Jorge; Moatshe, Gilbert; LaPrade, Robert F.

    2016-01-01

    Background: In recent years there has been an increasing interest in high tibial osteotomy (HTO) to treat patients with chronic knee instability due to posterolateral corner (PLC), posterior cruciate ligament (PCL), and anterior cruciate ligament (ACL) insufficiencies with concurrent malalignment in the coronal and/or sagittal plane. Purpose: To perform a systematic review of the use of HTO for the treatment of knee ligament instability with concurrent malalignment. Study Design: Systematic review; Level of evidence, 4. Methods: A systematic review of the literature was conducted for the treatment of combined knee ligament instability and malalignment with HTO using the Cochrane Central Register of Controlled Trials, PubMed, and MEDLINE (1980 to present); the queries were performed in July 2015. Terms searched included the following: high or proximal tibial osteotomy, unstable, instability, laxity, subluxation, tibial slope, and malalignment, in the knee joint. Inclusion criteria were as follows: HTO to treat instability of the knee joint in the sagittal and/or coronal plane, minimum 2-year follow-up with reported outcomes measures, English language, and human studies. Animal, basic science, and cadaveric studies were excluded as well as editorials, reviews, expert opinions, surveys, special topics, letters to the editor, and correspondence. Results: The search resulted in 460 studies. After applying exclusion criteria and removing duplicates, 13 studies were considered. Of the studies reviewed, knee ligament pathologies, previous surgeries, and measurement of knee stability were heterogeneous. However, all studies reported an improvement in knee stability after HTO. Most studies reported improvement in outcome scores. However, other studies did not provide preoperative scores for comparison. Reported complication rates ranged from 0% to 47%. Conclusion: Although HTO has been highly advocated and used in treating patients with ligamentous knee instability, there

  8. Analysis of the Tibial Epiphysis in the Skeletally Immature Knee Using Magnetic Resonance Imaging

    PubMed Central

    Davis, Derik L.; Almardawi, Ranyah; Mitchell, Jason W.

    2016-01-01

    Background: Physeal-sparing anterior cruciate ligament (ACL) reconstruction is being performed increasingly in skeletally immature knees. Purpose: To determine normal values for the maximum oblique length and “safe” physeal-sparing length and their corresponding angular trajectories across the tibial epiphysis on reconstructed magnetic resonance images (MRIs) in children and adolescents. Study Design: Cross-sectional study; Level of evidence, 3. Methods: An electronic search for pediatric knee MR examinations from April 2003 to April 2013 was performed at our institution. A 3-dimensional system viewer was used to measure the maximum oblique length, physeal-sparing length, and their corresponding angular trajectories on reconstructed MRIs. Knees were stratified by age into 2 groups: group 1 consisted of boys <13 years and girls <12 years and group 2 consisted of older boys (13-14 years) and girls (12-14 years). Each cohort was further stratified by sex. Group 1 consisted of 36 knees (mean age, 10.9 years) and group 2 consisted of 59 knees (mean age, 13.6 years). Results: Significant differences existed for the maximum oblique length and its angular trajectory for the younger versus older cohort (22.2 ± 2.7 vs 23.8 ± 2.7 mm, P = .007; 42.0° ± 4.0° vs 39.4° ± 4.2°, P = .003) and for the physeal-sparing length and its angular trajectory (19.4 ± 2.8 vs 21.3 ± 2.9 mm, P = .001; 30.1° ± 4.1° vs 28.2° ± 4.5°, P = .042). In group 2, females had shorter maximal oblique length and physeal-sparing length than boys (22.7 ± 2.3 vs 25.0 ± 2.7 mm, P < .001; 20.3 ± 2.6 vs 22.4 ± 2.9 mm, P = .004). Conclusion: The maximum oblique length across the tibial epiphysis is shorter than previously believed, measuring approximately 22 mm and approximately 24 mm for high- and intermediate-risk knees, respectively. However, “safe” physeal-sparing lengths were only approximately 19 mm and 21 mm for the younger and older cohorts, respectively. The angles

  9. Anatomic Anterolateral Ligament Reconstruction of the Knee Leads to Overconstraint at any Fixation Angle

    PubMed Central

    Schon, Jason; Brady, Alex; Moatshe, Gilbert; Cruz, Raphael; Chahla, Jorge; Dornan, Grant; Turnbull, Travis L.; Engebretsen, Lars

    2016-01-01

    Objectives: Anterior cruciate ligament (ACL) tears are one of the most common injuries among athletes. However, the ability to fully restore rotational stability with ACL reconstruction (ACLR) remains a challenge because up to 25% of patients may present with a residual pivot shift following surgery. Advocacy for reconstruction of the anterolateral ligament (ALL) is rapidly increasing because biomechanical studies have reported that the ALL is a significant contributor to internal rotational stability of the knee. Although several graft fixation angles for the anatomic ALL reconstruction (ALLR) have been reported in literature, none have been biomechanically validated. Therefore, the purpose of this study was to assess the effect of ALLR graft fixation angle on knee joint kinematics in the clinically relevant setting of a concomitant ACLR. The goal was to find the optimal knee flexion angle for fixation of the ALLR graft that would most accurately restore native knee kinematics without introducing overconstraint to the knee. It was hypothesized that all fixation angles would significantly reduce rotational laxity compared to the sectioned ALL state and that fixation at 30° would best reproduce native joint kinematics. Methods: Eight non-paired fresh-frozen human cadaveric knees with no prior injury, surgical history, or gross anatomic abnormality were evaluated with a 6 degree-of-freedom robotic system. Each specimen underwent a full kinematic assessment in each of the following states: 1) intact, 2) anatomic single-bundle (SB) ACLR with intact ALL, 3) anatomic SB ACLR with sectioned ALL, 4) 7 anatomic SB ACLR and ALLR states utilizing ALL graft fixation knee flexion angles of 0°, 15°, 30°, 45°, 60°, 75° and 90°, and 5) sectioned ACL and ALL. Internal rotation during a 5 N-m internal rotation torque and anterior displacement during an 88 N anterior load were recorded at 15° intervals between 0° and 120° of knee flexion. Axial plane displacement and

  10. Effects of Two Football Stud Types on Knee and Ankle Kinetics of Single-Leg Land-Cut and 180° Cut Movements on Infilled Synthetic Turf.

    PubMed

    Bennett, Hunter J; Brock, Elizabeth; Brosnan, James T; Sorochan, John C; Zhang, Songning

    2015-10-01

    Higher ACL injury rates have been recorded in cleats with higher torsional resistance in American football, which warrants better understanding of shoe/stud-dependent joint kinetics. The purpose of this study was to determine differences in knee and ankle kinetics during single-leg land cuts and 180° cuts on synthetic infilled turf while wearing 3 types of shoes. Fourteen recreational football players performed single-leg land cuts and 180° cuts in nonstudded running shoes (RS) and in football shoes with natural (NTS) and synthetic turf studs (STS). Knee and ankle kinetic variables were analyzed with a 3 × 2 (shoe × movement) repeated-measures ANOVA (P < .05). A significant shoe-by-movement interaction was found in loading response peak knee adduction moments, with NTS producing smaller moments compared with both STS and RS only in 180° cuts. Reduced peak negative plantar flexor powers were also found in NTS compared with STS. The single-leg land cut produced greater loading response and push-off peak knee extensor moments, as well as peak negative and positive extensor and plantar flexor powers, but smaller loading peak knee adduction moments and push-off peak ankle eversion moments than 180° cuts. Overall, the STS and 180° cuts resulted in greater frontal plane knee loading and should be monitored for possible increased ACL injury risks. PMID:25950515

  11. Nyquist and Bode stability criteria to assess changes in dynamic knee stability in healthy and anterior cruciate ligament reconstructed individuals during walking.

    PubMed

    Morgan, Kristin D; Zheng, Yanbing; Bush, Heather; Noehren, Brian

    2016-06-14

    Anterior cruciate ligament (ACL) injuries are one of the most frequently injured knee ligaments. Despite reconstruction, many individuals report difficulty returning to high level activities that require greater dynamic stability. Since few methods have been tested to assess dynamic stability post ACL reconstruction (ACLR), the purpose of this study was to evaluate between and within dynamic knee stability in control and ACLR individuals using Nyquist and Bode stability criteria. Sixteen control and sixteen post ACLR individuals performed a walking protocol. Nyquist and Bode stability criteria were implemented to classify and quantify individual step-to-step sagittal plane dynamic knee stability from the gait waveforms at initial contact, 15% and 30% of stance based on the resulting gain and phase margins. An ANOVA compared differences in phase margins between the control and ACLR limbs and found that the ACLR limbs were overall significantly more unstable than the non-reconstructed and control limbs (p=0.001). The results indicated that the ACLR individuals who exhibited stable steps adopted a more compensatory strategy aimed to stabilize the knee. These methods of evaluating dynamic knee stability may help clinicians to assess dynamic knee stability progression throughout rehabilitation and help assess return-to-sport with minimal risk to the individual. PMID:27126984

  12. Arthrometric evaluation of stabilizing effect of knee functional bracing at different flexion angles.

    PubMed

    Seyed Mohseni, Saeedeh; Moss, Farzam; Karimi, Hossein; Kamali, Mohammad

    2009-01-01

    Previous in-vivo investigations on the stabilizing efficacy of knee bracing for ACL reconstructed patients have been often limited to 20-30 degrees of knee flexion. In this study, the effectiveness of a uniaxial hinged functional brace to improve the knee stability was assessed at 30, 60 and 90 degrees of knee flexion. Arthrometry tests were conducted on 15 healthy subjects before and following wearing the brace and the tibial displacements were measured at up to 150 N anterior forces. Results indicated that functional bracing has a significant stabilizing effect throughout the range of knee flexion examined (p < 0.05). The rate of effectiveness, however, was not consistent across the flexion range, e.g., 50% at 30 degrees and only 4% at 90 degrees. It was suggested that accurate sizing and fitting as well as attention to correct hinge placement relative to the femoral condyles can limit brace migration and improve its effectiveness in mid and deep knee flexion. With using adaptive limb fittings, through flexible pads, and a polycentric joint a more significant improvement of the overall brace performance and efficacy might be obtained. Key pointsFunctional bracing improves the knee joint stability mostly in extension posture.Unlike the non-braced condition, the least knee joint stability appears in mid and deep flexion angles when using a hinged brace.Accurate sizing and fitting and attention to correct hinge placement relative to the femoral condyles can limit brace migration and improve its effectiveness in mid and deep knee flexion.The overall brace performance and efficacy might be improved significantly using adaptive limb fittings through flexible pads and/or polycentric joints. PMID:24149533

  13. Quality of Movement for Athletes Six Months Post ACL Reconstruction

    PubMed Central

    deMille, Polly; Nguyen, Joseph; Brown, Allison; Do, Huong; Selvaggio, Elizabeth; Chiaia, Theresa

    2016-01-01

    Objectives: Anterior cruciate ligament (ACL) injury prevention programs evaluate quality of movement (QM) to identify and correct high-risk movement patterns. However, return to play (RTP) decisions post-ACL reconstruction (ACLR) are often based on non-sport relatedquantitative measures such as isokinetic tests and/or time from surgery, with six months post-ACLR being a common expectation for RTP. The purpose of this study was to evaluate whether athletes are ready to RTP 6 months post ACLR using a QM assessment (QMA). Methods: A QMA including nine dynamic tasks (squat, single leg [SL] stance, step down, SL squat, jump in place, side to side jump, broad jump, hop to opposite, SL hop) progressing from double- to single-limb vertical and horizontal movements was administered to 136 athletes at five to seven months post-ACLR. Tasks were viewed from the frontal and sagittal planes by a physical therapist and performance specialist. Movements were evaluated live for risk factors associated with ACL injury (strategy, depth, control, symmetry, and alignment). The proportion of patients exhibiting risky movement patterns for each task was calculated. Fisher’s Exact test was used to determine if there were differences in movement patterns between males and females. Results: The proportion of patients demonstrating risky movement patterns for a task ranged from 48% to 100%. All 136 patients exhibited risky movement patterns for at least one task and 60% of patients displayed risky movement patterns in five or more of the nine tasks. Rates of risky movement patterns were not different between males and females for all tasks (P>0.1 for all tasks). Conclusion: Six months has been cited as a probable time for RTP post-ACLR; thus this is the expectation of the athlete. Our data show that athletes demonstrate multiple QM patterns associated with initial ACL injury, as well as 2nd injury at five to seven months post-operatively. Altered movement patterns evident in tasks as

  14. Physeal Disruption During ACL Reconstruction in Skeletally Immature Patients

    PubMed Central

    Cruz, Aristides Ignacio; Lakomkin, Nikita; Fabricant, Peter D.; Lawrence, John Todd R.

    2016-01-01

    Objectives: The purpose of this study was to radiographically assess differences in distal femoral physeal disruption between transtibial and independent femoral tunnel drilling techniques following ACL reconstruction in skeletally immature patients. Methods: A retrospective, matched comparative cohort study was performed of skeletally immature patients who underwent transphyseal ACL reconstruction between January 1, 2008 and March 31, 2011. All skeletally immature patients between ten and fifteen years old who underwent independent femoral tunnel drilling and had adequate baseline and post-operative radiographs were analyzed. These patients were matched with a transtibial technique cohort based on age and sex. Demographic characteristics and peri-operative metrics were collected. Radiographic measurements were recorded from pre-operative MRI and post-operative plain radiographs. Results: Twenty patients were analyzed. Between groups, there were significant differences between independent tunnel drilling and transtibial tunnel drilling in the estimated area of physeal disruption (1.64 cm2 vs. 0.74 cm2, P<0.001), femoral (32.1º vs. 72.8º, P<0.001) and tibial (50.1º vs. 60.5º, P=0.003) tunnel angles, medial/lateral location of the femoral tunnel (24.2 mm vs. 36.1 mm from lateral cortex, P=0.001), and distance from the lateral aspect of the distal femoral physis and the femoral tunnel exit (4.7 mm vs. 26.7 mm from the perichondrial ring, P<0.001), respectively. All patients who underwent femoral tunnel drilling at an angle of less than 25º from the transverse axis experienced a greater than 6% disruption of physeal area. There was a significant inverse correlation between femoral tunnel angle and estimated area of femoral physeal involvement (r=-0.8255, P=0.003). Conclusion: With femoral tunnel drilling techniques that create more oblique tunnels, the area of distal femoral physeal damage is larger, more eccentric and closer to the perichondrial ring. Since most

  15. Original Rehabilitation Programme after Anatomical ACL Reconstruction Based on MRI Evaluated Graft Remodelling

    PubMed Central

    Plenzler, Marcin; Straszewski, Dariusz; Ciszkowska-Łysoń, Beata; Śmigielski, Robert; Popieluch, Marcin

    2014-01-01

    Objectives: This study was carried out to design a rehabilitation program allowing for complete functional post-surgical recovery of the limb, that would not affect the remodelling process of the transplanted graft evaluated on MRI imaging. The main reason for changing the rehabilitation protocol was the 14 months of observation of the MRI images (a series of 9 MRIs performed over a two year period) among the patients after ACL reconstruction, in whom the adverse characteristics in remodelling of the graft were observed in line with the implementation of the traditional rehabilitation program. Methods: A 23 years old patient, a professional hi-rank skateboarder, took part in this pilot study. He had a torsion injury of the left knee joint. The main concepts of the rehabilitation program were: functional training in CKC that would involve muscles of the entire kinetic chain of the operated limb; the co-contraction training under the axial load, active extension training, the avoidance of static flexor stretching for at least 24 weeks after the surgery, no passive movements while exercising, the use of posterior translation of the tibia while doing the exercises, and no knee joint extensor strengthening activities in OKC for at least six months after the surgery. In order to evaluate the remodelling of the graft, seven oblique axial MR images (DOA) were taken, on which the graft’s cross-sectional area was measured. The MRI's were performed in the second, sixth, and twelfth week; then in the fourth, sixth, and ninth month, and, finally a year after the surgery. The angle of the graft and PCL was also measured. Additionally, the quality of tendon signal was assessed. For the functional evaluation, isokinetic and isometric tests of the knee extensor and the flexor muscles, along with the tibial rotator functions were performed using Humac Norm device. Postural stability based on COP parameter was established, as well, using the stabilometric platform HUR. For the

  16. Recent Advances in Computational Mechanics of the Human Knee Joint

    PubMed Central

    Kazemi, M.; Dabiri, Y.; Li, L. P.

    2013-01-01

    Computational mechanics has been advanced in every area of orthopedic biomechanics. The objective of this paper is to provide a general review of the computational models used in the analysis of the mechanical function of the knee joint in different loading and pathological conditions. Major review articles published in related areas are summarized first. The constitutive models for soft tissues of the knee are briefly discussed to facilitate understanding the joint modeling. A detailed review of the tibiofemoral joint models is presented thereafter. The geometry reconstruction procedures as well as some critical issues in finite element modeling are also discussed. Computational modeling can be a reliable and effective method for the study of mechanical behavior of the knee joint, if the model is constructed correctly. Single-phase material models have been used to predict the instantaneous load response for the healthy knees and repaired joints, such as total and partial meniscectomies, ACL and PCL reconstructions, and joint replacements. Recently, poromechanical models accounting for fluid pressurization in soft tissues have been proposed to study the viscoelastic response of the healthy and impaired knee joints. While the constitutive modeling has been considerably advanced at the tissue level, many challenges still exist in applying a good material model to three-dimensional joint simulations. A complete model validation at the joint level seems impossible presently, because only simple data can be obtained experimentally. Therefore, model validation may be concentrated on the constitutive laws using multiple mechanical tests of the tissues. Extensive model verifications at the joint level are still crucial for the accuracy of the modeling. PMID:23509602

  17. Preventing Knee Injuries

    MedlinePlus

    ... to tearing. Growth Plate Injuries, Fractures, and Dislocations Knee fractures rarely occur in childhood sports, but with any ... is the bump on the front of the knee where the patellar tendon attaches. Fractures to the growth plate in this area often ...

  18. Vitamin D supplementation in the management of knee osteoarthritis: study protocol for a randomized controlled trial

    PubMed Central

    2012-01-01

    Background Osteoarthritis (OA) is a common health issue worldwide in the aging population who are also commonly deficient in vitamin D. Our previous study suggested that higher serum 25-(OH)D levels were associated with reduced knee cartilage loss, implying that vitamin D supplementation may prevent the progression of knee OA. The aim of the VItamin D Effects on OA (VIDEO) study is to compare, over a 2- year period, the effects of vitamin D supplementation versus placebo on knee structural changes, knee pain, and lower limb muscle strength in patients with symptomatic knee OA. Methods/design Randomised, placebo-controlled, and double-blind clinical trial aiming to recruit 400 subjects (200 from Tasmania and 200 from Victoria) with both symptomatic knee OA and vitamin D deficiency (serum [25-(OH)D] level of >12.5 nmol/liter and <60 nmol/liter). Participants will be randomly allocated to vitamin D supplementation (50,000 IU compounded vitamin D3 capsule monthly) or identical inert placebo group for 2 years. The primary endpoint is loss of knee cartilage volume measured by magnetic resonance imaging (MRI) and Western Ontario and McMaster Universities Index of OA (WOMAC) knee pain score. The secondary endpoints will be other knee structural changes, and lower limb muscle strength. Several other outcome measures including core muscle images and central blood pressure will be recorded. Linear and logistic regression will be used to compare changes between groups using univariable and multivariable modeling analyses. Both intention to treat and per protocol analyses will be utilized. Discussion The trial is designed to test if vitamin D supplementation will reduce loss of knee cartilage volume, prevent the progression of other knee structural abnormalities, reduce knee pain and strengthen lower limb muscle strength, thus modify disease progression in knee OA. Trial registration ClinicalTrials.gov identifier: NCT01176344; Australian New Zealand Clinical Trials

  19. Evaluating ACLS Algorithms for the International Space Station (ISS) - A Paradigm Revisited

    NASA Technical Reports Server (NTRS)

    Alexander, Dave; Brandt, Keith; Locke, James; Hurst, Victor, IV; Mack, Michael D.; Pettys, Marianne; Smart, Kieran

    2007-01-01

    The ISS may have communication gaps of up to 45 minutes during each orbit and therefore it is imperative to have medical protocols, including an effective ACLS algorithm, that can be reliably autonomously executed during flight. The aim of this project was to compare the effectiveness of the current ACLS algorithm with an improved algorithm having a new navigation format.

  20. Perspectives on the Humanities and School-Based Curriculum Development. ACLS Occasional Paper No. 24.

    ERIC Educational Resources Information Center

    Blackman, Sandra; Chodorow, Stanley; Ohmann, Richard; Okura, Sandra; Purrington, Sandra Sanchez; Stein, Robert

    This paper records three plenary sessions held at the American Council of Learned Societies (ACLS) National Education Conference, August 27-29, 1993. The conference built on what was learned in the first year of the project and reported in ACLS Occasional Paper 20. Sessions allowed participants to talk with colleagues who had been project…

  1. Liberal Arts Colleges in American Higher Education: Challenges and Opportunities. ACLS Occasional Paper, No. 59

    ERIC Educational Resources Information Center

    American Council of Learned Societies, 2005

    2005-01-01

    This American Council of Learned Societies (ACLS) Occasional Paper presents the proceedings of a conference on "Liberal Arts Colleges in American Higher Education: Challenges and Opportunities" convened by ACLS in November 2003 in Williamstown, Massachusetts with the support of the Oakley Center for the Humanities and Social Sciences at Williams…

  2. Bicompartmental knee arthroplasty

    PubMed Central

    Giachino, Matteo; Risitano, Salvatore; Atzori, Francesco

    2016-01-01

    Total knee arthroplasty (TKA) is the most worldwide practiced surgery for knee osteoarthritis and its efficacy is mightily described by literature. Concerns about the invasiveness of TKA let the introduction of segmental resurfacing of the joint for younger patients with localized osteoarthritis. Bone stock sparing and ligaments preservation are the essence of both unicompartmental knee arthroplasty (UKA) and bicompartmental knee arthroplasty (BKA). Advantages related to BKA are the respect of knee biomechanics, lower complications rates, shorter hospital stay, faster rehabilitation. Moreover, in case of failure of the first implant the conversion to TKA is undemanding and can be compared to a standard prosthesis. Our experience suggest that BKA is a reliable technique in selected cases and especially younger people with higher functional requests can favourably profit from it. Although those results are encouraging, we still need further prospective, randomized, long-term studies to finally assess BKA indications and outcomes. PMID:26855941

  3. Bicompartmental knee arthroplasty.

    PubMed

    Sabatini, Luigi; Giachino, Matteo; Risitano, Salvatore; Atzori, Francesco

    2016-01-01

    Total knee arthroplasty (TKA) is the most worldwide practiced surgery for knee osteoarthritis and its efficacy is mightily described by literature. Concerns about the invasiveness of TKA let the introduction of segmental resurfacing of the joint for younger patients with localized osteoarthritis. Bone stock sparing and ligaments preservation are the essence of both unicompartmental knee arthroplasty (UKA) and bicompartmental knee arthroplasty (BKA). Advantages related to BKA are the respect of knee biomechanics, lower complications rates, shorter hospital stay, faster rehabilitation. Moreover, in case of failure of the first implant the conversion to TKA is undemanding and can be compared to a standard prosthesis. Our experience suggest that BKA is a reliable technique in selected cases and especially younger people with higher functional requests can favourably profit from it. Although those results are encouraging, we still need further prospective, randomized, long-term studies to finally assess BKA indications and outcomes. PMID:26855941

  4. Intra-articular cysts and ganglia of the knee: a report of nine patients.

    PubMed

    Sarimo, Janne; Rantanen, Jussi; Helttula, Ilmo; Orava, Sakari

    2005-01-01

    Completely intra-articular cysts and ganglia of the knee are rare. They have been found in various locations such as on the anterior or posterior cruciate ligaments, in the infrapatellar fat pad, on the posterior wall of the posteromedial compartment and (very rarely) in connection to the menisci. We analyzed nine patients with intra-articular cysts or ganglia found in a series of 2,400 consecutive arthroscopies. In four patients, the cyst or ganglion was found attached to the anterior part of the ACL, in two patients it was located between the ACL and the PCL, and in the remaining three cases it was found in connection with the meniscus. In three out of the nine patients there was either no or very minor additional pathology found in the knee besides the cyst or the ganglion. We believe that intra-articular cysts and ganglia of the knee can be symptomatic, and excellent or good results after cyst removal can be expected especially when there is little additional pathology. PMID:15654646

  5. Identification of factors associated with the development of knee osteoarthritis in a young to middle-aged cohort of patients with knee complaints.

    PubMed

    Huétink, Kasper; Stoel, Berend C; Watt, Iain; Kloppenburg, Margreet; Bloem, Johan L; Malm, Steve H; Van't Klooster, Ronald; Nelissen, Rob G H H

    2015-10-01

    The objective of this study was to identify risk factors for knee osteoarthritis (OA) development in a young to middle-aged population with sub-acute knee complaints. This, in order to define high risk patients who may benefit from early preventive or future disease modifying therapies. Knee OA development visible on radiographs and MR in 319 patients (mean age 41.5 years) 10 years after sub-acute knee complaints and subjective knee function (KOOS score) was studied. Associations between OA development and age, gender, activity level, BMI, meniscal or anterior cruciate ligament (ACL) lesions, OA in first-degree relatives and radiographic hand OA were determined using multivariable logistic regression analysis. OA on radiographs and MR in the TFC is associated with increased age (OR: 1.10, 95 % 1.04-1.16 and OR: 1.07, 95 % 1.02-1.13). TFC OA on radiographs only is associated with ACL and/or meniscal lesions (OR: 5.01, 95 % 2.14-11.73), presence of hand OA (OR: 4.69, 95 % 1.35-16.32) and higher Tegner activity scores at baseline before the complaints (OR: 1.20, 95 % 1.01-1.43). The presence of OA in the TFC diagnosed only on MRI is associated with a family history of OA (OR: 2.44, 95 % 1.18-5.06) and a higher BMI (OR: 1.13, 95 % 1.04-1.23). OA in the PFC diagnosed on both radiographs and MR is associated with an increased age (OR: 1.06, 95 % 1.02-1.12 and OR: 1.05, 95 % 1.00-1.09). PFC OA diagnosed on radiographs only is associated with a higher BMI (OR: 1.12, 95 % 1.02-1.22). The presence of OA in the PFC diagnosed on MR only is associated with the presence of hand OA (OR: 3.39, 95 % 1.10-10.50). Compared to normal reference values, the study population had significantly lower KOOS scores in the different subscales. These results show that knee OA development in young to middle aged patients with a history of sub-acute knee complaints is associated with the presence of known risk factors for knee OA. OA is already visible on radiographs and MRI after 10

  6. Congenital longitudinal deficiency of the tibia.

    PubMed

    Spiegel, D A; Loder, R T; Crandall, R C

    2003-01-01

    We performed a clinical and radiographic review of 15 patients (19 limbs) with longitudinal deficiency of the tibia treated between 1981 and 2001. Ten limbs with Kalamchi type I deficiencies were managed by through-knee amputation. Five type II deficiencies were treated by foot ablation and tibiofibular synostosis, either at the same time or staged, but prosthetic problems may arise from varus alignment and prominence of the proximal fibula. Patients with type III deficiencies (four cases) were treated by foot ablation. Prosthetic problems relating to proximal or distal tibiofibular instability may necessitate additional surgical intervention. PMID:12879290

  7. 50 CFR 622.12 - Annual catch limits (ACLs) and accountability measures (AMs) for Caribbean island management...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... lb (26,524 kg). (R) Spiny lobster—327,920 lb (148,742 kg). (ii) Recreational ACLs. The following ACLs... (15,242 kg). (N) Triggerfish and filefish, combined—24,980 lb (11,331 kg). (O) Spiny lobster—107,307...). (O) Spiny lobster—104,199 lb (47,264 kg). (ii) (4) Caribbean EEZ— (i) ACLs. The following ACLs...

  8. 50 CFR 622.12 - Annual catch limits (ACLs) and accountability measures (AMs) for Caribbean island management...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... lb (26,524 kg). (R) Spiny lobster—327,920 lb (148,742 kg). (ii) Recreational ACLs. The following ACLs... (15,242 kg). (N) Triggerfish and filefish, combined—24,980 lb (11,331 kg). (O) Spiny lobster—107,307...). (O) Spiny lobster—104,199 lb (47,264 kg). (ii) (4) Caribbean EEZ— (i) ACLs. The following ACLs...

  9. Treating Osteoarthritis of the Knee

    MedlinePlus

    ... osteotomy may need knee replacement surgery in the future. Arthroplasty is also called joint or knee replacement therapy. A surgeon removes the part of the knee damaged by osteoarthritis and replaces it with an artificial joint made from metals and plastic. All or part of the knee joint may ...

  10. Clinical Instability of the Knee and Functional Differences Following Tibial Plateau Fractures Versus Distal Femoral Fractures

    PubMed Central

    Ebrahimzadeh, Mohammad Hosein; Birjandinejad, Ali; Moradi, Ali; Fathi Choghadeh, Maysam; Rezazadeh, Jafar; Omidi-Kashani, Farzad

    2015-01-01

    Background: Fractures of the knee account for about 6% of all trauma admissions. While its management is mostly focused on fracture treatment, it is not the only factor that defines the final outcome. Objectives: This study aimed to study objective and subjective outcomes after proximal tibial versus distal femoral fractures in terms of knee instability and health-related quality of life. Patients and Methods: This retrospective, cross-sectional, cohort study was carried out on 80 patients with either isolated proximal tibial (n = 42) or distal femoral (n = 38) fractures, who underwent open reduction and internal fixation. All the fractures were classified based on the Schatzker and AO classification for tibial plateau and distal femoral fractures, respectively. The patients were followed and examined by an orthopedic knee surgeon for clinical assessment of knee instability. In their last follow-up visit, these patients completed a Lysholm knee score and the short-form (SF) 36 health survey. Results: Among the 42 tibial plateau fractures, 25% were classified as Schatzker type 2. Of the 38 distal femoral fractures, we did not find any type B1 or B3 fractures. The overall prevalence of anterior and posterior instability was 42% and 20%, respectively. Medial Collateral Ligament (MCL) and Lateral Collateral Ligament (LCL) injuries were detected clinically in 50% and 28%, respectively. The incidence rates of ligament injuries in tibial plateau fractures were as follows: Anterior Collateral Ligament (ACL) 26%, Posterior Collateral Ligament (PCL) 7%, MCL 24%, and LCL 14%. Medial collateral ligament injury was the most common in the Schatzker type 2 (50% of the injuries). Distal femoral fractures were associated with ACL injury in 16%, PCL in 13%, MCL in 26% and LCL in 14%. However, final knee range of motion (ROM) and function (Lysholm score) were not associated with fracture location. No statistically significant difference was observed between the two groups, except for

  11. The effect of a novel movement strategy in decreasing ACL risk factors in female adolescent soccer players.

    PubMed

    Celebrini, Richard G; Eng, Janice J; Miller, William C; Ekegren, Christina L; Johnston, James D; MacIntyre, Donna L

    2012-12-01

    There is a need to investigate the effect of specific movement strategies in reducing biomechanical risk factors for anterior cruciate ligament injury in young female athletes. The purpose of this study was (a) to determine the feasibility of implementing a novel movement strategy (Core-PAC) into a team warm-up before soccer training based on subject compliance and integration of the Core-PAC into the warm-up and (b) to determine whether the Core-PAC would improve peak knee flexion angles and peak abduction moments at the knee during a side cut (SC) and an unanticipated side cut (USC) before kicking a soccer ball, and a side hop (SH) task after immediate instruction and after a 4-week training program. A convenience sample of ten 14- to 16-year-old female soccer players were instructed in the Core-PAC immediately after baseline testing and during a training program consisting of a 20-minute warm-up, 2 times per week. The Core-PAC was understood and accepted by the subjects and incorporated into their warm-up activities with good compliance. After the immediate instruction, there were significant increases in peak knee flexion angles of a mean 6.4° during the SC (p = 0.001), 3.5° during the USC (p = 0.007), and 5.8° during the SH (p < 0.001) tasks. Peak knee abduction moments decreased by a mean of 0.25 N·m·kg(-1) during the SC (p < 0.03), 0.17 N·m·kg(-1) during the USC (p = 0.05), and 0.27 N·m·kg(-1) during the SH (p = 0.04) tasks. After the 4-week training program, some individuals showed improvement. The results of this study suggest that the Core-PAC may be 1 method of modifying high-risk movements for ACL injury such as side cutting and single-leg landing. PMID:22210470

  12. Advanced concepts in knee arthrodesis

    PubMed Central

    Wood, Jennifer H; Conway, Janet D

    2015-01-01

    The aim is to describe advanced strategies that can be used to diagnose and treat complications after knee arthrodesis and to describe temporary knee arthrodesis to treat infected knee arthroplasty. Potential difficult complications include nonunited knee arthrodesis, limb length discrepancy after knee arthrodesis, and united but infected knee arthrodesis. If a nonunited knee arthrodesis shows evidence of implant loosening or failure, then bone grafting the nonunion site as well as exchange intramedullary nailing and/or supplemental plate fixation are recommended. If symptomatic limb length discrepancy cannot be satisfactorily treated with a shoe lift, then the patient should undergo tibial lengthening over nail with a monolateral fixator or exchange nailing with a femoral internal lengthening device. If a united knee arthrodesis is infected, the nail must be removed. Then the surgeon has the option of replacing it with a long, antibiotic cement-coated nail. The authors also describe temporary knee arthrodesis for infected knee arthroplasty in patients who have the potential to undergo insertion of a new implant. The procedure has two goals: eradication of infection and stabilization of the knee. A temporary knee fusion can be accomplished by inserting both an antibiotic cement-coated knee fusion nail and a static antibiotic cement-coated spacer. These advanced techniques can be helpful when treating difficult complications after knee arthrodesis and treating cases of infected knee arthroplasty. PMID:25793160

  13. Osteochondral Allograft Transplantation in the Knee.

    PubMed

    Zouzias, Ioannis C; Bugbee, William D

    2016-06-01

    The technique of osteochondral allograft (OCA) transplantation has been used to treat a wide spectrum of cartilage deficiencies in the knee. Its use has been supported by basic science and clinical studies that show it is a safe and effective treatment option. What sets fresh OCA transplantation apart from other cartilage procedures in the knee, is the ability to treat large defects with mature hyaline cartilage. Studies looking at transplantation of fresh OCAs in the general population have shown reliable pain relief and return to activities of daily living. Reports of cartilage injuries in athletes have risen over the years and more research is needed in evaluating the successfulness of OCA transplantation in the athletic population. PMID:27135291

  14. Prognosis and predictors of ACL reconstructions using the MOON cohort: a model for comparative effectiveness studies.

    PubMed

    Spindler, Kurt P; Parker, Richard D; Andrish, Jack T; Kaeding, Christopher C; Wright, Rick W; Marx, Robert G; McCarty, Eric C; Amendola, Annunziato; Dunn, Warren R; Huston, Laura J; Harrell, Frank E

    2013-01-01

    Injury to the anterior cruciate ligament (ACL) threatens an active lifestyle and exposes the patient to risk of early osteoarthritis (OA). ACL reconstruction is typically chosen by individuals to allow a return to their previous work and sports activities. Primary ACL reconstruction (ACLR) has in general been effective at restoring functional stability, but patients' modifiable predictors of both short- and long-term validated outcomes and OA are largely unknown. The Multicenter Orthopaedic Outcomes Network (MOON) consortium was established in 2002 to enroll and longitudinally follow a population cohort of ACL reconstructed patients. The objective was to establish patient-specific predictive models of clinically important outcomes. Over the past 10 years, the overarching aims of this NIAMS-funded prospective multicenter cohort of ACL reconstructions has been threefold: (1) to identify both short- and long-term prognosis and predictors of sports function, activity level, and general health through validated patient-reported outcomes, (2) to identify the symptoms and signs of OA, and (3) to quantify the incidence of ACL reconstruction graft and/or contralateral ACL failures and additional surgical procedures. This manuscript summarizes the Kappa Delta Ann Doner Vaughan Award paper and presentation at the 2012 ORS/AAOS Annual Meeting. PMID:22912340

  15. The Effect of Skeletal Maturity on the Regenerative Function of Intrinsic ACL Cells

    PubMed Central

    Mastrangelo, Ashley N.; Magarian, Elise M.; Palmer, Matthew P.; Vavken, Patrick; Murray, Martha M.

    2010-01-01

    Anterior cruciate ligament (ACL) injuries are an important clinical problem, particularly for adolescent patients. The effect of skeletal maturity on the potential for ACL healing is as yet unknown. In this study, we hypothesized that fibroblastic cells from the ACLs of skeletally immature animals would proliferate and migrate more quickly than cells from adolescent and adult animals. ACL tissue from skeletally immature, adolescent, and adult pigs and sheep were obtained and cells obtained using explant culture. Cell proliferation within a collagen–platelet scaffold was measured at days 2, 7, and 14 of culture using AMMTT assay. Cellular migration was measured at 4 and 24 h using a modified Boyden chamber assay, and cell outgrowth from the explants also measured at 1 week. ACL cells from skeletally immature animals had higher proliferation between 7 and 14 days (p < 0.01 for all comparisons) and higher migration potential at all time points in both species (p < 0.01 for all comparisons).ACL cells from skeletally immature animals have greater cellular proliferation and migration potential than cells from adolescent or adult animals. These experiments suggest that skeletal maturity may influence the biologic repair capacity of intrinsic ACL cells. PMID:19890988

  16. Knee MRI scan

    MedlinePlus

    ... magnetic resonance imaging) scan uses energy from strong magnets to create pictures of the knee joint and ... in your eyes) Because the MRI contains strong magnets, metal objects are not allowed into the room ...

  17. Anterior knee pain

    MedlinePlus

    ... places extra stress on the kneecap (such as running, jumping or twisting, skiing, or playing soccer). You ... noticeable with: Deep knee bends Going down stairs Running downhill Standing up after sitting for awhile

  18. Total Knee Replacement

    MedlinePlus

    ... as anti- inflammatory medications, cortisone injections, lubricating injections, physical therapy, or other surgeries A knee that has become ... your function. Other treatment options — including medications, injections, physical therapy, or other types of surgery — will also be ...

  19. Tourniquetless Total Knee Arthroplasty

    MedlinePlus Videos and Cool Tools

    Tourniquetless Total Knee Arthroplasty You must have Javascript enabled in your web browser. View Program Transcript Click Here to view the OR-Live, Inc. Privacy Policy and Legal Notice © 2010 OR- ...

  20. Taking care of your new knee joint

    MedlinePlus

    Knee arthroplasty - precautions; Knee replacement - precautions ... After you have knee replacement surgery , you will need to be careful about how you move your knee, especially for the first few months after ...

  1. Reading Knee-Deep

    ERIC Educational Resources Information Center

    Jewett, Pamela

    2007-01-01

    Freire told his audience at a seminar at the University of Massachusetts, "You need to read knee-deep in texts, for deeper than surface meanings, and you need to know the words to be able to do it" (quoted in Cleary, 2003). In a children's literature class, fifteen teachers and I traveled along a path that moved us toward reading knee-deep as we…

  2. Dashboard (in the) knee.

    PubMed

    Patel, M S; Qureshi, A A; Green, T P

    2015-03-01

    We present the case of a 19-year-old individual presenting to an orthopaedic outpatient clinic several months following a dashboard knee injury during a road traffic accident with intermittent mechanical symptoms. Despite unremarkable examination findings and normal magnetic resonance imaging, the patient was identified subsequently as having an intra-articular plastic foreign body consistent with a piece of dashboard on arthroscopic knee assessment, the retrieval of which resulted in a complete resolution of symptoms. PMID:25723676

  3. Comparison of Indirect MR Arthrography With Conventional MRI in the Diagnosis of Knee Pathologies in Patients With Knee Pain

    PubMed Central

    Babaei Jandaghi, Ali; Mardani-Kivi, Mohsen; Mirbolook, Ahmadreza; Emami-Meybodi, Mohammad Kazem; Mohammadzadeh, Solmaz; Farahmand, Maral

    2016-01-01

    Background Knee pain is a common problem in the general population. In order to determine the extent of the injury and the appropriate treatment, MRI provides the most accurate imaging method. This may be done through conventional MRI techniques or by injecting a contrast material (MR arthrography). Objectives The purpose of this study was to compare the diagnostic value of these two methods. Patients and Methods The study involved the diagnostic evaluation on 60 patients with knee pain who received treatment over the course of a one-year period. Referred patients were randomly divided into two groups: indirect MR arthrography was performed on one group, and conventional MRI was performed on the other group. Both groups then underwent arthroscopy. The results from both groups were compared with the arthroscopic findings. Results In all of the pathologies studied, the sensitivity, specificity, and the positive and negative predictive values were evaluated. A high rate of accuracy was found between MR arthrography and arthroscopy (P < 0.05) for all knee injuries, however a similar rate of accuracy between conventional MRI and arthroscopy was only seen in patients with damage to the posterior cruciate ligament (PCL), the tibio-femoral articular cartilage, and patella chondromalacia (P < 0.05). The highest rate of accuracy was seen in cases where indirect MR arthrography was used for the diagnosis of anterior cruciate ligament (ACL) damage (K = 1). Conclusions Our results have shown that indirect MR arthrography had greater diagnostic accuracy in regards to the sensitivity, specificity, and positive and negative predictive values than conventional MRI in knee pathologies. PMID:27625998

  4. Non-invasive, non-radiological quantification of anteroposterior knee joint ligamentous laxity

    PubMed Central

    Russell, D. F.; Deakin, A. H.; Fogg, Q. A.; Picard, F.

    2013-01-01

    Objectives We performed in vitro validation of a non-invasive skin-mounted system that could allow quantification of anteroposterior (AP) laxity in the outpatient setting. Methods A total of 12 cadaveric lower limbs were tested with a commercial image-free navigation system using trackers secured by bone screws. We then tested a non-invasive fabric-strap system. The lower limb was secured at 10° intervals from 0° to 60° of knee flexion and 100 N of force was applied perpendicular to the tibia. Acceptable coefficient of repeatability (CR) and limits of agreement (LOA) of 3 mm were set based on diagnostic criteria for anterior cruciate ligament (ACL) insufficiency. Results Reliability and precision within the individual invasive and non-invasive systems was acceptable throughout the range of flexion tested (intra-class correlation coefficient 0.88, CR 1.6 mm). Agreement between the two systems was acceptable measuring AP laxity between full extension and 40° knee flexion (LOA 2.9 mm). Beyond 40° of flexion, agreement between the systems was unacceptable (LOA > 3 mm). Conclusions These results indicate that from full knee extension to 40° flexion, non-invasive navigation-based quantification of AP tibial translation is as accurate as the standard validated commercial system, particularly in the clinically and functionally important range of 20° to 30° knee flexion. This could be useful in diagnosis and post-operative evaluation of ACL pathology. Cite this article: Bone Joint Res 2013;2:233–7. PMID:24184443

  5. Which one Enhances Muscular Performance in ACL Reconstructed Subjects

    PubMed Central

    Harput, Gulcan; Ulusoy, Burak; Atay, Ahmet Ozgur; Baltacı, Gul

    2014-01-01

    Objectives: The aim of this study was to investigate the effects of functional knee brace and kinesiotaping on muscular performance in anterior cruciate ligament reconstructed subjects who reached return to sport phase of the rehabilitation. Methods: Twenty (17 males, 3 females, Age: 24.7±7.1 years, Body weight: 74.4±12.0 kg, Height: 177.9±6.5 cm, BMI: 23.9±3.6 kg/m2) subjects who underwent anterior cruciate ligament reconstruction by using hamstring tendon auto graft were included in this study. When the subjects reached the return to sports phase of rehabilitation which was 6th months after surgery, knee muscle strength, jump performance and balance tests were performed 3 times: bare, with knee brace and with kinesio taping. The order of the tests were randomized to eliminate the effects of fatigue and motor learning. Quadriceps and hamstring muscle strength was measured on an isokinetic dynamometer at 180 °/s and 60°/s angular velocities. Vertical Jump (VJ) and One Leg Hop Tests (OLHT) were used to assess jump performance. Star Excursion Balance Test (SEBT) with anterior, posteromedial and posterolateral reach distance was used to assess the dynamic balance. When all tests were performed, the subjects were asked under which test condition they felt more confident. Repeated measures of ANOVA was used to analyze the difference among three test conditions (bare, kinesiotaping, knee brace). Bonferroni post hoc test was used for pairwise comparison. Results: SEBT posteromedial (PM)and posterolateral (PL) reach distances were found significantly different among three test conditions(PM: F(2,38)=3.42,p=0.04), PL: F(2,38)=4.37,p=0.02). Kinesiotaping increased posteromedial reach distance (p=0.03). On the other hand, brace decreased posterolateral reach distance (p=0.04). VJ and OLHT performance were also found significantly different between three test conditions (VJ: F (2,38)=3.44,p=0.04, OLHT: (F(2,38)=4.04,p=0.02). Kinesio taping increased one leg hop distance

  6. Inter-segmental Postural Coordination Measures Differentiate Athletes with ACL Reconstruction from Uninjured Athletes

    PubMed Central

    Kiefer, Adam W.; Ford, Kevin R.; Paterno, Mark V.; Schmitt, Laura C.; Myer, Gregory D.; Riley, Michael A.; Shockley, Kevin; Hewett, Timothy E.

    2012-01-01

    Athletes who sustain non-contact anterior cruciate ligament (ACL) injuries and undergo surgical reconstruction exhibit deficits in sensorimotor control, which often impairs lower-limb movement coordination. The purpose of this experiment was to measure the influence of sensorimotor deficits on the ankle-hip coordination of a postural coordination task in athletes following ACL reconstruction. Twenty-two female athletes who were cleared to return to sports participation following ACL reconstruction and 22 uninjured female athletes performed a unilateral dynamic postural rhythmic coordination task at two movement frequencies (0.2 and 0.7 Hz). Athletes with ACL-reconstruction exhibited greater ankle-hip relative phase variability and reduced regularity of coupling than uninjured athletes, especially during the 0.2 Hz condition. The results of this study show altered lower extremity coordination patterns in athletes following ACL reconstruction and return to sports participation. The results also indicate that dynamical coordination measures may provide objective measures of sensorimotor deficits following ACL reconstruction and can potentially guide rehabilitation interventions following reconstruction. PMID:23219784

  7. The Use of Biologic Agents in Athletes with Knee Injuries.

    PubMed

    Kopka, Michaela; Bradley, James P

    2016-07-01

    Biologic agents are gaining popularity in the management of bony and soft tissue conditions about the knee. They are becoming the mainstay of nonoperative therapy in the high-demand athletic population. The most well-studied agents include platelet-rich plasma (PRP) and stem cells-both of which have shown promise in the treatment of various conditions. Animal and clinical studies have demonstrated improved outcomes following PRP treatment in early osteoarthritis of the knee, as well as in chronic patellar tendinopathy. Early clinical evidence also lends support for PRP in the augmentation of anterior cruciate ligament (ACL) reconstruction. Research investigating the role of biologic agents in collateral ligament and meniscal injuries is ongoing. Studies assessing the utility of stem cells have shown encouraging results in the setting of osteoarthritis. Unfortunately, strict regulations by the FDA continue to restrict their application in clinical practice. A major limitation in the interpretation of current data is the significant variability in the harvesting and preparation of both PRP and stem cells. As the volume and quality of evidence continue to grow, biologic agents are poised to become an integral component of comprehensive patient care throughout all orthopedic specialties. PMID:27206071

  8. Cementless total knee arthroplasty

    PubMed Central

    Risitano, Salvatore; Sabatini, Luigi; Giachino, Matteo; Agati, Gabriele; Massè, Alessandro

    2016-01-01

    Interest for uncemented total knee arthroplasty (TKA) has greatly increased in recent years. This technique, less used than cemented knee replacement in the last decades, sees a revival thanks an advance in prosthetic design, instrumentation and operative technique. The related literature in some cases shows conflicting data on survival and on the revision’s rate, but in most cases a success rate comparable to cemented TKA is reported. The optimal fixation in TKA is a subject of debate with the majority of surgeons favouring cemented fixation. PMID:27162779

  9. Primary rotating-hinge total knee arthroplasty: good outcomes at mid-term follow-up.

    PubMed

    Kowalczewski, Jacek; Marczak, Dariusz; Synder, Marek; Sibiński, Marcin

    2014-06-01

    We evaluated the clinical and radiologic outcomes of primary knee replacements using a rotating-hinge knee prosthesis in 12 knees with a minimum follow-up of 10 years. Indications for the operation included gross joint destruction, significant axial deformities and contracture with a dysfunctional medial collateral ligament in all cases. The patients' WOMAC and Knee Society scores improved, and the use of mobility aids decreased. No loosening of implants was observed. Nonprogressive radiolucent lines were identified around three tibial components. Three patients required marginal wound excision with resuturing and thereafter healed uneventfully. With significant improvement in function, pain and range of motion, the rotating-hinge knee prosthesis can be used as a salvage device in patients with medial collateral ligament deficiency, contracture, and gross joint destruction. PMID:24418767

  10. [An experimental study on the replacement of the anterior cruciate ligament of the rabbit's knee using an augmented substitute].

    PubMed

    Kitsuda, M

    1993-04-01

    The mechanical properties of a reconstruction of the anterior cruciate ligament (ACL) using an augmented substitute were investigated in rabbits' knees. After total resection of the ACL, 25 knees were reconstructed with a patellar tendon alone (nonaugmented group) and 25 with a patella tendon augmented by a Leeds-Keio artificial ligament (augmented group). The rabbits were sacrificed for biomechanical testing at 0, 4, 8, 12 and 24 weeks, respectively, after operation. In the augmented group, the mean ultimate load was 48.8% of the original ACL load at 4 weeks, and this gradually increased to 65.6% at 8 weeks. That of the twenty-four-week specimens was restored to 71% of the original ACL load. In the nonaugmented group, the mean ultimate load decreased to 9.3% at 8 weeks, but increased to 37.5% at 24 weeks. The mean static stiffness in the augmented group was higher than in the nonaugmented group at all time periods. The differences between the augmented and nonaugmented groups were statistically significant in the 8 to 12 week period (p < 0.01). Tan delta values, exhibiting the magnitude of viscosity in a viscoelastic material, in the augmented group were significantly higher than those in the nonaugmented group at 8 weeks (p < 0.05) and 12 weeks (p < 0.01). The mean tan delta in the augmented group decreased to 0.08 +/- 0.04 at 24 weeks, but the values were higher than those of the original ACL. The mean dynamic elastic modulus in the augmented group was higher than in the nonaugmented group at all time periods. The difference between the augmented and nonaugmented groups was statistically significant in the 8th week (p < 0.05). The values of dynamic elastic modulus in both groups were increased at 24 weeks: 96.4 MPa in the augmented group, and 77.5 MPa in the nonaugmented group. It was demonstrated that the augmented ligaments used for anterior cruciate ligament reconstruction had greater strength and static stiffness than the patellar tendon autograft. As for

  11. Bone bruises in anterior cruciate ligament injured knee and long-term outcomes. A review of the evidence

    PubMed Central

    Papalia, Rocco; Torre, Guglielmo; Vasta, Sebastiano; Zampogna, Biagio; Pedersen, Douglas R; Denaro, Vincenzo; Amendola, Annunziato

    2015-01-01

    Background Bone bruises are frequently associated with anterior cruciate ligament (ACL) tears as a result of trauma or direct shear stress of the bone. Purpose To review the evidence regarding the characteristics of the bone bruise associated with ACL tears, its relevance on clinical outcomes, and its progression over time. In particular, the long-term effects of the bone bruise on the knee osteochondral architecture and joint function were evaluated. Study design Review; level of evidence: 4. Methods An electronic search was performed on PubMed. Combinations of keywords included: “bone bruise AND knee”; “bone bruise AND anterior cruciate ligament”; “bone bruise AND osteo-chondral defects”. Any level of evidence studies concerning bone bruises in patients with partial or complete ACL tears were retrieved. Results A total of 25 studies were included; three of them investigated biomechanical parameters, seven were concerned with clinical outcomes, and 15 were radiological studies. Evaluation of the bone bruise is best performed using a fat-saturated T2-weighted fast spin echo exam or a short tau inversion recovery sequence where fat saturation is challenging. The location of the injury has been demonstrated to be more frequent in the lateral compartment of the joint (lateral femoral condyle and lateral tibial plateau). It is associated with ACL tears in approximately 70% of cases, often with collateral ligament or meniscal tears. Mid- and long-term outcomes demonstrated a complete healing of the marrow lesions at magnetic resonance imaging, but chondral defects detected with T1ρ sequences are still present 1 year after the ACL injury. Functional examination of the knee, through clinical International Knee Documentation Committee scores, did not show any correlation with the bone bruise. Conclusion Although bone bruise presence yields to higher pain levels, no correlation with functional outcomes was reported. Most studies have a short-term follow-up (<2

  12. Knee imaging after anterior cruciate ligament reconstruction.

    PubMed

    Rodrigues, M B; Silva, J J; Homsi, C; Stump, X M; Lecouvet, F E

    2001-01-01

    An increasing number of reconstructions of the anterior cruciate ligament (ACL) are performed every year, due to both the increasing occurrence of sport related injuries and the development of diagnostic and surgical techniques. The most used surgical procedure for the torn ACL reconstruction is the use of autogenous material, most often the patellar and semitendinosus tendons. Magnetic resonance (MR) imaging and spiral-CT performed after arthrography with multiplanar reconstructions are the imaging methods of choice for post-operative evaluation of ACL ligamentoplasty. This paper provides a brief bibliographic and more extensive pictorial review of the normal evolution and possible complications after ACL repair. PMID:11817479

  13. Description of an evaluation system for knee kinematics in ligament lesions, by means of optical tracking and 3D tomography☆☆☆

    PubMed Central

    Fernandes, Tiago Lazzaretti; Ribeiro, Douglas Badillo; da Rocha, Diogo Cristo; Albuquerque, Cyro; Pereira, César Augusto Martins; Pedrinelli, André; Hernandez, Arnaldo José

    2014-01-01

    Objective To describe and demonstrate the viability of a method for evaluating knee kinematics, by means of a continuous passive motion (CPM) machine, before and after anterior cruciate ligament (ACL) injury. Methods This study was conducted on a knee from a cadaver, in a mechanical pivot-shift simulator, with evaluations using optical tracking, and also using computed tomography. Results This study demonstrated the viability of a protocol for measuring the rotation and translation of the knee, using reproducible and objective tools (error < 0.2 mm). The mechanized provocation system of the pivot-shift test was independent of the examiner and always allowed the same angular velocity and traction of 20 N throughout the movement. Conclusion The clinical relevance of this method lies in making inferences about the in vivo behavior of a knee with an ACL injury and providing greater methodological quality in future studies for measuring surgical techniques with grafts in relatively close positions. PMID:26229854

  14. Tibiofemoral cartilage contact biomechanics in patients after reconstruction of a ruptured anterior cruciate ligament.

    PubMed

    Hosseini, Ali; Van de Velde, Samuel; Gill, Thomas J; Li, Guoan

    2012-11-01

    We investigated the in vivo cartilage contact biomechanics of the tibiofemoral joint in patients after reconstruction of a ruptured anterior cruciate ligament (ACL). A dual fluoroscopic and MR imaging technique was used to investigate the cartilage contact biomechanics of the tibiofemoral joint during in vivo weight-bearing flexion of the knee in eight patients 6 months following clinically successful reconstruction of an acute isolated ACL rupture. The location of tibiofemoral cartilage contact, size of the contact area, cartilage thickness at the contact area, and magnitude of the cartilage contact deformation of the ACL-reconstructed knees were compared with those previously measured in intact (contralateral) knees and ACL-deficient knees of the same subjects. Contact biomechanics of the tibiofemoral cartilage after ACL reconstruction were similar to those measured in intact knees. However, at lower flexion, the abnormal posterior and lateral shift of cartilage contact location to smaller regions of thinner tibial cartilage that has been described in ACL-deficient knees persisted in ACL-reconstructed knees, resulting in an increase of the magnitude of cartilage contact deformation at those flexion angles. Reconstruction of the ACL restored some of the in vivo cartilage contact biomechanics of the tibiofemoral joint to normal. Clinically, recovering anterior knee stability might be insufficient to prevent post-operative cartilage degeneration due to lack of restoration of in vivo cartilage contact biomechanics. PMID:22528687

  15. Randomized Trial of a Novel ACLS Teaching Tool: Does it Improve Student Performance?

    PubMed Central

    Nacca, Nicholas; Holliday, Jordan; Ko, Paul Y.

    2014-01-01

    Introduction Mounting evidence suggests that high-fidelity mannequin-based (HFMBS) and computer-based simulation are useful adjunctive educational tools for advanced cardiac life support (ACLS) instruction. We sought to determine whether access to a supplemental, online computer-based ACLS simulator would improve students’ performance on a standardized Mega Code using high-fidelity mannequin based simulation (HFMBS). Methods Sixty-five third-year medical students were randomized. Intervention group subjects (n = 29) each received a two-week access code to the online ACLS simulator, whereas the control group subjects (n = 36) did not. Primary outcome measures included students’ time to initiate chest compressions, defibrillate ventricular fibrillation, and pace symptomatic bradycardia. Secondary outcome measures included students’ subjective self-assessment of ACLS knowledge and confidence. Results Students with access to the online simulator on average defibrillated ventricular fibrillation in 112 seconds, whereas those without defibrillated in 149.9 seconds, an average of 38 seconds faster [p<.05]. Similarly, those with access to the simulator paced symptomatic bradycardia on average in 95.14 seconds whereas those without access paced on average 154.9 seconds a difference of 59.81 seconds [p<.05]. On a subjective 5-point scale, there was no difference in self-assessment of ACLS knowledge between the control (mean 3.3) versus intervention (mean 3.1) [p-value =.21]. Despite having outperformed the control group subjects in the standardized Mega Code test scenario, the intervention group felt less confident on a 5-point scale (mean 2.5) than the control group. (mean 3.2) [p<.05] Conclusion The reduction in time to defibrillate ventricular fibrillation and to pace symptomatic bradycardia among the intervention group subjects suggests that the online computer-based ACLS simulator is an effective adjunctive ACLS instructional tool. PMID:25493153

  16. Hypermobility and Knee Injuries.

    ERIC Educational Resources Information Center

    Steiner, Mark E.

    1987-01-01

    A review of research on the effect of hypermobility on knee injury indicates that greater than normal joint flexibility may be necessary for some athletic endeavors and that it may be possible to change one's underlying flexibility through training. However, for most athletes, inherited flexibility probably plays only a small role, if any, in…

  17. 21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Knee joint tibial (hemi-knee) metallic resurfacing... Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis is a device intended to be...

  18. 49 CFR 572.136 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 7 2014-10-01 2014-10-01 false Knees and knee impact test procedure. 572.136... Hybrid III 5th Percentile Female Test Dummy, Alpha Version § 572.136 Knees and knee impact test procedure. (a) Knee assembly. The knee assembly (refer to §§ 572.130(a)(1)(v) and (vi)) for the purpose of...

  19. 21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Knee joint tibial (hemi-knee) metallic resurfacing... Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis is a device intended to be...

  20. 49 CFR 572.126 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 7 2012-10-01 2012-10-01 false Knees and knee impact test procedure. 572.126...-year-old Child Test Dummy, Beta Version § 572.126 Knees and knee impact test procedure. (a) Knee assembly. The knee assembly is part of the leg assembly (drawing 127-4000-1 and -2). (b) When the...

  1. 21 CFR 888.3580 - Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Knee joint patellar (hemi-knee) metallic... § 888.3580 Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis is a device made...

  2. 49 CFR 572.136 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Knees and knee impact test procedure. 572.136... Hybrid III 5th Percentile Female Test Dummy, Alpha Version § 572.136 Knees and knee impact test procedure. (a) Knee assembly. The knee assembly (refer to §§ 572.130(a)(1)(v) and (vi)) for the purpose of...

  3. 21 CFR 888.3580 - Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Knee joint patellar (hemi-knee) metallic... § 888.3580 Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis is a device made...

  4. 49 CFR 572.126 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false Knees and knee impact test procedure. 572.126...-year-old Child Test Dummy, Beta Version § 572.126 Knees and knee impact test procedure. (a) Knee assembly. The knee assembly is part of the leg assembly (drawing 127-4000-1 and -2). (b) When the...

  5. 21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Knee joint tibial (hemi-knee) metallic resurfacing... Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis is a device intended to be...

  6. 49 CFR 572.126 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 7 2011-10-01 2011-10-01 false Knees and knee impact test procedure. 572.126...-year-old Child Test Dummy, Beta Version § 572.126 Knees and knee impact test procedure. (a) Knee assembly. The knee assembly is part of the leg assembly (drawing 127-4000-1 and -2). (b) When the...

  7. 49 CFR 572.136 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false Knees and knee impact test procedure. 572.136... Hybrid III 5th Percentile Female Test Dummy, Alpha Version § 572.136 Knees and knee impact test procedure. (a) Knee assembly. The knee assembly (refer to §§ 572.130(a)(1)(v) and (vi)) for the purpose of...

  8. 49 CFR 572.126 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Knees and knee impact test procedure. 572.126...-year-old Child Test Dummy, Beta Version § 572.126 Knees and knee impact test procedure. (a) Knee assembly. The knee assembly is part of the leg assembly (drawing 127-4000-1 and -2). (b) When the...

  9. 49 CFR 572.126 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 7 2014-10-01 2014-10-01 false Knees and knee impact test procedure. 572.126...-year-old Child Test Dummy, Beta Version § 572.126 Knees and knee impact test procedure. (a) Knee assembly. The knee assembly is part of the leg assembly (drawing 127-4000-1 and -2). (b) When the...

  10. 21 CFR 888.3580 - Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Knee joint patellar (hemi-knee) metallic... § 888.3580 Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis is a device made...

  11. 49 CFR 572.136 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 7 2012-10-01 2012-10-01 false Knees and knee impact test procedure. 572.136... Hybrid III 5th Percentile Female Test Dummy, Alpha Version § 572.136 Knees and knee impact test procedure. (a) Knee assembly. The knee assembly (refer to §§ 572.130(a)(1)(v) and (vi)) for the purpose of...

  12. 21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

  13. 21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Knee joint tibial (hemi-knee) metallic resurfacing... Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis is a device intended to be...

  14. 49 CFR 572.136 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 7 2011-10-01 2011-10-01 false Knees and knee impact test procedure. 572.136... Hybrid III 5th Percentile Female Test Dummy, Alpha Version § 572.136 Knees and knee impact test procedure. (a) Knee assembly. The knee assembly (refer to §§ 572.130(a)(1)(v) and (vi)) for the purpose of...

  15. Comparison of volumetric bone mineral density in the operated and contralateral knee after anterior cruciate ligament and reconstruction: A 1-year follow-up study using peripheral quantitative computed tomography.

    PubMed

    Mündermann, Annegret; Payer, Nina; Felmet, Gernot; Riehle, Hartmut

    2015-12-01

    The purpose of this study was to quantify changes in volumetric bone mineral density (vBMD) in the tibial plateau of the operated and contralateral leg measured using peripheral quantitative computed tomography (pQCT) before and 3, 6, and 12 months after anterior cruciate ligament (ACL) reconstruction. The ACL was reconstructed with a hamstring tendon autograft using press-fit fixation. pQCT measurements of the proximal tibia were obtained in 61 patients after ACL reconstruction, and total, cortical, and trabecular vBMD were calculated. vBMD in the operated leg decreased from baseline to 3 months (-12% [total], -11% [cortical], and -12.6% [trabecular]; p<0.001) and remained below baseline for 12 months after surgery (6 months: -9.5%, -9.4%, and -9.6%, p<0.001; 12 months: -8%, -5%, and -11%, p<0.001). vBMD in the contralateral leg was slightly reduced only 6 months after surgery. Including age and sex as covariates into the analysis did not affect the results. ACL reconstruction contributed to loss in bone mineral density within the first year after surgery. The role of factors such as time of weight-bearing, joint mechanics, post-traumatic inflammatory reactions, or genetic predisposition in modulating the development of posttraumatic knee osteoarthritis after ACL injury should be further elucidated. PMID:26123943

  16. Intercondylar Notch Stenosis of Knee Osteoarthritis and Relationship between Stenosis and Osteoarthritis Complicated with Anterior Cruciate Ligament Injury

    PubMed Central

    Chen, Cong; Ma, Yinhua; Geng, Bin; Tan, Xiaoyi; Zhang, Bo; Jayswal, Chandan Kumar; Khan, Md. Shahidur; Meng, Huiqiang; Ding, Ning; Jiang, Jin; Wu, Meng; Wang, Jing; Xia, Yayi

    2016-01-01

    Abstract The aim of this study was to research whether the patients with knee osteoarthritis (OA) exist intercondylar notch stenosis and the relationship between stenosis and OA complicated with anterior cruciate ligament (ACL) injury from magnetic resonance imaging (MRI). A total of 79 cases of moderate–severe OA patients and 71 cases of healthy people were collected; among these OA patients, 38 were OA complicated with ACL injury and 41 were simple OA. The intercondylar notch was divided into A, U, and W types according to the notch shape in the axial sequence of MRI. Measurement of the notch width index (NWI) in the sequences of axial (NWI-1), coronal (NWI-2), and ACL attachment point at femoral (NWI-A) was done. The differences of NWI in different groups and different sequences were compared and the NWI cut-off values in different sequences were resolved by a receiver operating characteristic (ROC) curve which could be used as indicators for intercondylar notch narrowing were calculated. The proportion of type A in moderate–severe OA group was larger than healthy group, and similar to OA complicated with ACL injury and simple OA groups (P <0.05). The NWI values of the moderate–severe OA group in three sequences were smaller than the healthy group, and similar to OA complicated with ACL injury and simple OA groups (P <0.001). The cut-off values of ROC curve were NWI-1 <0.266, NWI-2 <0.247, and NWI-A <0.253 in the moderate–severe OA group, and NWI-1 <0.263, NWI-2 <0.246, and NWI-A <0.253 in the OA complicated with ACL injury group. The intercondylar notch of moderate–severe OA patients exist significant stenosis. Type A is one of the variables that predispose a notch to stenosis. Intercondylar notch stenosis and type A are risk factors for moderate–severe OA patients complicated with ACL injury. PMID:27124033

  17. The transosseous ACL Refixation and biological Augmentation "TARBA". Preliminary Results of a new Operation Technique

    PubMed Central

    Hinterwimmer, Stefan; Achten, Manfred; Bathish, Einal

    2016-01-01

    Aims and Objectives: Differentiated gradings of anterior cruciate ligament (ACL) tear-types allow us to perform a more and more differentiated treatment of this injury. Especially in the tears close to the insertion ACL preserving techniques like "healing response" together with growth factors or synthetic augmentations of the original ACL like the "dynamic intraligamentous stabilization DIS" have increasing importance. Disadvantages of the mentioned techniques are the limited indications and the high need of material. That led us to the development of the "transosseous ACL refixation and biological augmentation TARBA", in which the original ACL is refixed to the femoral insertion and augmented with the patient’s doubled gracilis tendon. In the following we will present the first results with this technique. Materials and Methods: From 12/2013 to 02/2015 we used this technique in 56 patients (28x m, 28x f, age 30.7years). All patients had ACL tears in the proximal third close to the femoral insertion. The original ACL was fixed arthroscopically with 2 PDS fibres. Those were pulled out of the femur through a 5mm channel. The original-ACL was augmented with a doubled ipsilateral gracilis tendon. This tendon graft was pulled into the joint via another tibial 5mm channel and fixed at the femur with an endobutton and at the tibia with a cortical anchor screw. Both channels were placed exactly adjacent to the centre of the femoral and tibial anatomic insertion sites. The treatment result was controlled after 3, 6, 9 and 12 months with clinical examination and various scores (patient satisfaction, VAS, Lysholm, Tegner, Activity Rating Scale). After 6 months an instrumented stability test (Rolimeter) was performed. All patients were matched with 47 patients who had a complete ACL tear treated with 4-strand stemitendinosus tendon (control group). Results: Until now all patients with "TARBA" were satisfied with their operation. The range of motion was equal to the healthy

  18. Arthroscopic verification of objectivity of the orthopaedic examination and magnetic resonance imaging in intra-articular knee injury. Retrospective study

    PubMed Central

    Skowronek, Michał; Skowronek, Paweł; Dutka, Łukasz

    2011-01-01

    Introduction Arthroscopy of the knee joint is regarded as the most objective diagnostic method in intra-articular knee joint lesions. Aim The purpose of this study was to assess the objectivity and diagnostic value of orthopaedic examination (OE) and magnetic resonance imaging (MRI) in reference to the arthroscopic result. Material and methods In a group of 113 patients treated by arthroscopic surgery for post-traumatic knee pathology between 2008 and 2010 in our department, accuracy of clinical and MRI findings that preceded surgery were studied retrospectively using a statistical method. Sensitivity, specificity, accuracy and predictive negative and positive values were the subject of analysis. Results In the presented trial, sensitivity values of the orthopaedic examination for injuries of the anterior cruciate ligament (ACL), meniscus medialis (MM), meniscus lateralis (ML) and chondral injuries (ChI) were 86%, 65%, 38% and 51%, respectively. Specificity values were 90%, 65%, 100% and 100%, respectively. The MR sensitivity and specificity values were 80%, 88%, 44% and 32%, and 86%, 64%, 93% and 97%, respectively. Conclusions Assessment of intra-articular knee joint lesions is a difficult diagnostic problem. In making a decision about arthroscopy of the knee joint, an appropriate sequence of examinations should be carried out: OE, MRI and arthroscopy. The improvement in the effectiveness of the orthopaedic examination and MRI can limit the too high frequency of diagnostic arthroscopies, which generates the risk of operation treatment and costs. PMID:23255995

  19. Displaced Medial and Lateral Bucket Handle Meniscal Tears With Intact ACL and PCL.

    PubMed

    Boody, Barrett S; Omar, Imran M; Hill, James A

    2015-08-01

    Bucket handle lesions are vertical longitudinal tears in the meniscus that may displace centrally into the respective medial or lateral compartment, frequently causing mechanical symptoms, including pain, perceived instability, and mechanical locking. Bucket handle meniscal tears are most commonly from a traumatic etiology and are frequently found with concomitant anterior cruciate ligament (ACL) injuries. Multiple imaging signs and associations have been described for the diagnosis of bucket handle meniscus tears, including coronal truncation, absent bow tie sign, double posterior cruciate ligament (PCL), double ACL, displacement of the bucket handle fragment, and disproportionate posterior horn signs. Among meniscal pathology encountered on magnetic resonance imaging or during arthroscopy, bucket handle meniscal tears are infrequent occurrences. Furthermore, the occurrence of displaced medial and lateral bucket handle tears found on imaging and during arthroscopy is very uncommon and is only sparsely reported in the literature. When displaced medial and lateral bucket handle meniscal segments are visualized within the intercondylar notch along with the ACL and PCL, the radiologic findings are referred to as the "quadruple cruciate" sign or the "Jack and Jill lesion." Of the few case reports described in the literature, only one noted displaced medial and lateral bucket handle meniscus tears with an intact ACL and PCL. The current case report outlines a similar rare case of the quadruple cruciate sign: displaced medial and lateral bucket handle meniscal tears located within the intercondylar notch and an intact ACL and PCL. PMID:26270763

  20. Negative feedback regulation of auxin signaling by ATHB8/ACL5-BUD2 transcription module.

    PubMed

    Baima, Simona; Forte, Valentina; Possenti, Marco; Peñalosa, Andrés; Leoni, Guido; Salvi, Sergio; Felici, Barbara; Ruberti, Ida; Morelli, Giorgio

    2014-06-01

    The role of auxin as main regulator of vascular differentiation is well established, and a direct correlation between the rate of xylem differentiation and the amount of auxin reaching the (pro)cambial cells has been proposed. It has been suggested that thermospermine produced by ACAULIS5 (ACL5) and bushy and dwarf2 (BUD2) is one of the factors downstream to auxin contributing to the regulation of this process in Arabidopsis. Here, we provide an in-depth characterization of the mechanism through which ACL5 modulates xylem differentiation. We show that an increased level of ACL5 slows down xylem differentiation by negatively affecting the expression of homeodomain-leucine zipper (HD-ZIP) III and key auxin signaling genes. This mechanism involves the positive regulation of thermospermine biosynthesis by the HD-ZIP III protein Arabidopsis thaliana homeobox8 tightly controlling the expression of ACL5 and BUD2. In addition, we show that the HD-ZIP III protein REVOLUTA contributes to the increased leaf vascularization and long hypocotyl phenotype of acl5 likely by a direct regulation of auxin signaling genes such as like auxin resistant2 (LAX2) and LAX3. We propose that proper formation and differentiation of xylem depend on a balance between positive and negative feedback loops operating through HD-ZIP III genes. PMID:24777988

  1. Spontaneous Knee Ankylosis through Heterotopic Ossification after Total Knee Arthroplasty

    PubMed Central

    Boulezaz, Samuel; Gibon, Emmanuel; Loriaut, Philippe; Casabianca, Laurent; Rousseau, Romain; Dallaudiere, Benjamin; Pascal-Moussellard, Hugues

    2016-01-01

    This paper reports on a case of total ankylosis of the knee after a cruciate-sacrificing cemented total knee arthroplasty (TKA). An 82-year-old female patient previously underwent primary TKA for osteoarthritis twenty years ago in our institution. She had recovered uneventfully and returned to her regular activities. There was no history of postsurgical trauma; however, she progressively lost knee range of motion. Radiographs revealed severe bridging heterotopic ossification. PMID:27119034

  2. [Biomechanics of the knee joint].

    PubMed

    Witzel, U

    1993-01-01

    The capsular and ligamentous structures as control system of a healthy knee-joint supported by the muscular system are responsible for the rolling and gliding motion of the femoral condyles on the tibial plateau. Both the condyles and the tibial plateau have individually developed but to each other adjusted shapes and fine structures thereby. These structures consist of hyaline cartilage at their three-dimensional surfaces and of closely packed fibrils (lamina splendens) as the final gliding zone for tensile load. The orientation of the collagenous fibres can be made visible by split lines. The chondral surfaces are indirectly in contact to each other and orthogonally stressed at the particular point of contact. The indirect contact of the cartilaginous surfaces happens under interposition of the menisci. The meniscus serves to reduce and equalize the surface pressure by its own projected surface on the one hand and by maintaining of a hydraulic pressure of the synovial fluid on the other hand. Deviations of the condylar position as a result on ligamentous instabilities or ruptures with a following occurring loss of congruence, meniscal lesions or traumatic ruptures lead to a rapid discharge of the synovial fluid under load. The result is a hydraulic head loss with direct contact of the chondral surfaces under stress leading to arthrotic deformations. Severe arthrotic deformations or very much every meniscectomy produce intraarticular lumped loads resulting in a hyper-physiologic chondral pressure and malnutrition thereby. Further on there develop subchondral stress concentrations (caused by the lumped loads) leading to osseous damages, too. MR-pictures can make visible these damages. Chondromalacia, fissure or even chondrolysis are arthroscopically detectable sometimes. As after-effects of deficient knee ligaments occur pathological deviations of the femoral condyles and resulting destructions of the articular surfaces under stress enormously intensified by

  3. Can Platelet rich plasma stimulate human ACL growth in culture? A preliminary experience

    PubMed Central

    Dhillon, Mandeep Singh; Karna, Saroj Kumar; Dhatt, Sarvdeep Singh; Behera, Prateek; Bhatia, Alka

    2015-01-01

    Summary Introduction Platelet Rich Plasma (PRP) contains numerous growth factors; Platelet poor plasma (PPP) is plasma proteins without platelets, containing growth factors other than platelet derived. We planned to evaluate the effect of both autologous PRP & PPP on human ACL cell growth characteristics in culture conditions to see if one was better than the other. Methods ACL remnants were collected from eleven patients during ACL reconstruction surgery; PPP and PRP were prepared from blood of these patients. Cells were isolated, identified and cultured and were then divided into six groups. Groups A–D had Fetal Bovine Serum (FBS) added to them along with different concentrations of PRP and PPP. Groups E and F had 5% and 10% PRP respectively but lacked FBS. Cell viability was assayed by MTT and Annexin V assay, and DNA content was evaluated by propidium iodide staining and flow cytometry. Results analysis of cultured cells showed that addition of PRP (5 or 10%) increased the viability of ACL cells in 4 out of 11 and promoted cell proliferation in 8 of 11 donor samples; 10% PRP was more effective than 5% PRP. However, the difference in effectiveness of 10% PRP was not significantly better than 5% PRP. 5% PPP had no significant effect on cell viability, but it led to an increase in DNA content in 5 of 11. There was no statistically significant effect of either PRP or PPP in preventing cell death (depicted by apoptosis rate). Conclusion PRP may have an enhancing effect on ACL cell viability and promotion of cell proliferation but the ideal concentration of PRP for these positive effects needs to be determined before it could be used in clinical settings for enhancing primary repair of torn ACL. Also larger, more controlled and better studies are needed to confirm its clinical utility. PMID:26605188

  4. Advanced Cardiac Life Support (ACLS) utilizing Man-Tended Capability (MTC) hardware onboard Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Smith, M.; Barratt, M.; Lloyd, C.

    1992-01-01

    Because of the time and distance involved in returning a patient from space to a definitive medical care facility, the capability for Advanced Cardiac Life Support (ACLS) exists onboard Space Station Freedom. Methods: In order to evaluate the effectiveness of terrestrial ACLS protocols in microgravity, a medical team conducted simulations during parabolic flights onboard the KC-135 aircraft. The hardware planned for use during the MTC phase of the space station was utilized to increase the fidelity of the scenario and to evaluate the prototype equipment. Based on initial KC-135 testing of CPR and ACLS, changes were made to the ventricular fibrillation algorithm in order to accommodate the space environment. Other constraints to delivery of ACLS onboard the space station include crew size, minimum training, crew deconditioning, and limited supplies and equipment. Results: The delivery of ACLS in microgravity is hindered by the environment, but should be adequate. Factors specific to microgravity were identified for inclusion in the protocol including immediate restraint of the patient and early intubation to insure airway. External cardiac compressions of adequate force and frequency were administered using various methods. The more significant limiting factors appear to be crew training, crew size, and limited supplies. Conclusions: Although ACLS is possible in the microgravity environment, future evaluations are necessary to further refine the protocols. Proper patient and medical officer restraint is crucial prior to advanced procedures. Also emphasis should be placed on early intubation for airway management and drug administration. Preliminary results and further testing will be utilized in the design of medical hardware, determination of crew training, and medical operations for space station and beyond.

  5. Synovial plicae of the knee

    SciTech Connect

    Apple, J.S.; Martinez, S.; Daffner, R.H.; Gehweiler, J.A.; Hardaker, W.T.

    1982-01-01

    This report describes the anatomy, patho-physiology, clinical, and radiographic findings, and treatment of the synovial plicae of the knee joint. The suprapatellar plica is a synovial fold present in the suprapatellar pouch of the knee joint in approximately 20% of the population. This fold may become symptomatic after injury and cause symptoms similar to other common internal derangements of the knee. Double contrast arthrography of the knee can be used to identify the presence of plicae. Although arthrography can identify the presence of a plica, its clinical significance requires close correlation with symptoms and an accurate clinical examination.

  6. Multiligamentous injuries and knee dislocations.

    PubMed

    Gimber, Lana H; Scalcione, Luke R; Rowan, Andrew; Hardy, Jolene C; Melville, David M; Taljanovic, Mihra S

    2015-11-01

    Complex capsular ligamentous structures contribute to stability of the knee joint. Simultaneous injury of two or more knee ligaments, aside from concurrent tears involving the anterior cruciate and medial collateral ligaments, is considered to be associated with femorotibial knee dislocations. Proximal tibiofibular joint dislocations are not always easily recognized and may be overlooked or missed. Patellofemoral dislocations can be transient with MR imaging sometimes required to reach the diagnosis. In this article, the authors describe the mechanism of injury, ligamentous disruptions, imaging, and treatment options of various types of knee dislocations including injuries of the femorotibial, proximal tibiofibular, and patellofemoral joints. PMID:26002747

  7. 76 FR 61061 - Fisheries of the Northeastern United States; Atlantic Herring Fishery; Sub-ACL (Annual Catch...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-03

    ... is 38,146 mt and 0 mt of the sub-ACL is set aside for research (75 FR 48874, August 12, 2010). The... Northeastern United States; Atlantic Herring Fishery; Sub-ACL (Annual Catch Limit) Harvested for Management... 2,000 lb (907.2 kg) of Atlantic herring (herring) in or from Management Area 3 (Area 3) per...

  8. 77 FR 10668 - Fisheries of the Northeastern United States; Atlantic Herring Fishery; Sub-ACL (Annual Catch...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-23

    ... 22,146 mt, and 0 mt of the sub-ACL is set aside for research (75 FR 48874, August 12, 2010). Section... Northeastern United States; Atlantic Herring Fishery; Sub-ACL (Annual Catch Limit) Harvested for Management... Administration (NOAA), Commerce. ACTION: Temporary rule; closure. SUMMARY: NMFS is closing the directed...

  9. 76 FR 61059 - Fisheries of the Northeastern United States; Atlantic Herring Fishery; Sub-ACL (Annual Catch...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-03

    ...,362 mt and 0 mt of the sub-ACL is set aside for research (75 FR 48874, August 12, 2010). The... Northeastern United States; Atlantic Herring Fishery; Sub-ACL (Annual Catch Limit) Harvested for Management... 2,000 lb (907.2 kg) of Atlantic herring (herring) in or from Management Area 1B (Area 1B)...

  10. 78 FR 21071 - Fisheries of the Northeastern United States; Atlantic Herring Fishery; Sub-ACL (Annual Catch...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-09

    ...-ACL is set aside for research (75 FR 48874, August 12, 2010). The regulations at Sec. 648.201 require... Northeastern United States; Atlantic Herring Fishery; Sub-ACL (Annual Catch Limit) Harvested for Management... Administration (NOAA), Commerce. ACTION: Temporary rule; closure. SUMMARY: NMFS is closing the directed...

  11. 77 FR 66746 - Fisheries of the Northeastern United States; Atlantic Herring Fishery; Sub-ACL (Annual Catch...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-07

    ... research in the 2010-2012 specifications (75 FR 48874, August 12, 2010). However, due to an over-harvest in Area 1A in 2010, the FY 2012 sub-ACL in Area 1A was revised to 24,668 mt on February 24, 2012 (77 FR... Northeastern United States; Atlantic Herring Fishery; Sub-ACL (Annual Catch Limit) Harvested for...

  12. 76 FR 66654 - Fisheries of the Northeastern United States; Atlantic Herring Fishery; Sub-ACL (Annual Catch...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-27

    ... 1A is 26,546 mt, and 0 mt of the sub-ACL is set aside for research (75 FR 48874, August 12, 2010... Northeastern United States; Atlantic Herring Fishery; Sub-ACL (Annual Catch Limit) Harvested for Management... Administration (NOAA), Commerce. ACTION: Temporary rule; closure. SUMMARY: NMFS is closing the directed...

  13. 50 CFR 622.193 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... OF THE CARIBBEAN, GULF OF MEXICO, AND SOUTH ATLANTIC Snapper-Grouper Fishery of the South Atlantic... increase in the respective sector ACLs will be applied. (ii) (e) Black sea bass—(1) Commercial sector. (i... landings for black sea bass, as estimated by the SRD, are projected to reach the recreational ACL...

  14. 50 CFR 622.193 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... OF THE CARIBBEAN, GULF OF MEXICO, AND SOUTH ATLANTIC Snapper-Grouper Fishery of the South Atlantic... increase in the respective sector ACLs will be applied. (ii) (e) Black sea bass—(1) Commercial sector. (i... landings for black sea bass, as estimated by the SRD, are projected to reach the recreational ACL...

  15. Comparison of hamstring muscle behavior for anterior cruciate ligament (ACL) patient and normal subject during local marching

    NASA Astrophysics Data System (ADS)

    Amineldin@Aminudin, Nurul Izzaty Bt.; Rambely, A. S.

    2014-09-01

    This study aims to investigate the hamstring muscle activity after the surgery by carrying out an electromyography experiment on the hamstring and to compare the behavior of the ACL muscle activity between ACL patient and control subject. Electromyography (EMG) is used to study the behavior of muscles during walking activity. Two hamstring muscles involved which are semitendinosus and bicep femoris. The EMG data for both muscles were recorded while the subject did maximum voluntary contraction (MVC) and marching. The study concluded that there were similarities between bicep femoris of the ACL and control subjects. The analysis showed that the biceps femoris muscle of the ACL subject had no abnormality and the pattern is as normal as the control subject. However, ACL patient has poor semitendinosus muscle strength compared to that of control subject because the differences of the forces produced. The force of semitendinosus value for control subject was two times greater than that of the ACL subject as the right semitendinosus muscle of ACL subject was used to replace the anterior cruciate ligament (ACL) that was injured.

  16. Knee stabilization in patients with medial compartment knee osteoarthritis

    PubMed Central

    Lewek, Michael D.; Ramsey, Dan K.; Snyder-Mackler, Lynn; Rudolph, Katherine S.

    2005-01-01

    OBJECTIVE Individuals with medial knee osteoarthritis (MKOA) experience knee laxity and instability. Muscle stabilization strategies may influence the long term integrity of the joint. In this study we determined how individuals with medial knee OA respond to a rapid valgus knee movement to investigate the relationship between muscle stabilization strategies and knee instability. METHODS Twenty one subjects with MKOA and genu varum, and 19 control subjects were tested. Subjects stood with the test limb on a moveable platform that translated laterally to rapidly stress the knee’s medial periarticular structures and create a potentially destabilizing feeling at the knee joint. Knee motion and muscle responses were recorded. Subjects rated their knee instability with a self-report questionnaire about knee instability during daily activities. RESULTS Prior to plate movement the OA subjects demonstrated more medial muscle co-contraction (p=0.014). Following plate movement the OA subjects shifted less weight off the test limb (p = 0.013) and had more medial co-contraction (p=0.037). Those without instability had higher VMMH co-contraction than those who reported more instability (p=0.038). Knee stability correlated positively with VMMH co-contraction prior to plate movement (r = 0.459; p = 0.042). CONCLUSION This study demonstrates that individuals with MKOA attempt to stabilize the knee with greater medial muscle co-contraction in response to laxity that appears on only the medial side of the joint. This strategy presumably contributes to higher joint compression and could exacerbate joint destruction and needs to be altered to slow or stop the progression of the OA disease process. PMID:16142714

  17. Selectively Lockable Knee Brace

    NASA Technical Reports Server (NTRS)

    Myers, W. Neill (Inventor); Shadoan, Michael D. (Inventor); Forbes, John C. (Inventor); Baker, Kevin J. (Inventor); Rice, Darron C. (Inventor)

    1996-01-01

    A knee brace for aiding in rehabilitation of damaged leg muscles includes upper and lower housings normally pivotable one relative to the other about the knee joint axis of a patient. The upper housing is attachable to the thigh of the patient above the knee joint while the lower housing is secured to a stirrup which extends downwardly along the patient's leg and is attached to the patient's shoe. An actuation rod is carried within the lower housing and is coupled to a cable. The upper and lower housings carry cooperative clutch/brake elements which normally are disengaged to permit relative movement between the upper and lower housings. When the cable is extended the clutch/brake elements engage and lock the housings together. A heel strike mechanism fastened to the stirrup and the heel of the shoe is connected to the cable to selectively extend the cable and lock the brace in substantially any position when the patient places weight on the heel.

  18. Selectively lockable knee brace

    NASA Technical Reports Server (NTRS)

    Myers, Neill (Inventor); Shadoan, Mike (Inventor); Forbes, John (Inventor); Baker, Kevin (Inventor)

    1994-01-01

    A knee brace for aiding in rehabilitation of damaged leg muscles includes upper and lower housings, normally pivotable, one relative to the other about the knee joint axis of a patient. The upper housing is attachable to the thigh of the patient above the knee joint, while the lower housing is secured to a stirrup which extends downwardly along the patient's leg and is attached to the patient's shoe. An actuation rod is carried within the lower housing and is coupled to a cable. The upper and lower housings carry cooperative clutch/brake elements which normally are disengaged to permit relative movement between the upper and lower housings. When the cable is extended, the clutch/brake elements engage and lock the housings together. A heel strike mechanism fastened to the stirrup and the heel of the shoe is connected to the cable to selectively extend the cable and lock the brace in substantially any position when the patient places weight on the heel.

  19. Iron deficiency.

    PubMed

    Scrimshaw, N S

    1991-10-01

    The world's leading nutritional problem is iron deficiency. 66% of children and women aged 15-44 years in developing countries have it. Further, 10-20% of women of childbearing age in developed countries are anemic. Iron deficiency is identified with often irreversible impairment of a child's learning ability. It is also associated with low capacity for adults to work which reduces productivity. In addition, it impairs the immune system which reduces the body's ability to fight infection. Iron deficiency also lowers the metabolic rate and the body temperature when exposed to cold. Hemoglobin contains nearly 73% of the body's iron. This iron is always being recycled as more red blood cells are made. The rest of the needed iron does important tasks for the body, such as binds to molecules that are reservoirs of oxygen for muscle cells. This iron comes from our diet, especially meat. Even though some plants, such as spinach, are high in iron, the body can only absorb 1.4-7% of the iron in plants whereas it can absorb 20% of the iron in red meat. In many developing countries, the common vegetarian diets contribute to high rates of iron deficiency. Parasitic diseases and abnormal uterine bleeding also promote iron deficiency. Iron therapy in anemic children can often, but not always, improve behavior and cognitive performance. Iron deficiency during pregnancy often contributes to maternal and perinatal mortality. Yet treatment, if given to a child in time, can lead to normal growth and hinder infections. However, excess iron can be damaging. Too much supplemental iron in a malnourished child promotes fatal infections since the excess iron is available for the pathogens use. Many countries do not have an effective system for diagnosing, treating, and preventing iron deficiency. Therefore a concerted international effort is needed to eliminate iron deficiency in the world. PMID:1745900

  20. Longitudinal Sex Differences during Landing in Knee Abduction in Young Athletes

    PubMed Central

    Ford, Kevin R.; Shapiro, Robert; Myer, Gregory D.; Bogert, Antonie J. van den; Hewett, Timothy E.

    2010-01-01

    Purpose The objective of this study was to determine if biomechanical and neuromuscular risk factors related to abnormal movement patterns increased in females, but not males, during the adolescent growth spurt. Methods 315 subjects participated in two testing sessions approximately one year apart. Male and female subjects were classified based on their maturation status as pubertal or post-pubertal. Three trials of a drop vertical jump (DVJ) were collected. Maximum knee abduction angle and external moments were calculated during the DVJ deceleration phase using a 3D motion analysis system. Changes in knee abduction from the first to second year were compared among four subject groups (female pubertal, female post-pubertal, male pubertal and male post-pubertal). Results There were no sex differences in peak knee abduction angle or moment during DVJ between pubertal males and females (p>0.05). However, pubertal females increased peak abduction angle from the first to second year (p<0.001), while males demonstrated no similar change (p=0.90) in the matched developmental stages. Following puberty, the peak abduction angle and moment were greater in females relative to males (angle: female -9.3±5.7°, male -3.6±4.6°, p<0.001; moment: female:-21.9±13.5 Nm, male:-13.0±12.0 Nm, p=0.017). Conclusion This study identified, through longitudinal analyses, that knee abduction angle was significantly increased in pubertal females during rapid adolescent growth, while males showed no similar change. In addition, knee abduction motion and moments were significantly greater for subsequent year in young female athletes, following rapid adolescent growth, compared to males. The combination of longitudinal, sex and maturational group differences indicate that early puberty appears to be a critical phase related to the divergence of increased ACL injury risk factors. PMID:20305577

  1. Automatic locking orthotic knee device

    NASA Technical Reports Server (NTRS)

    Weddendorf, Bruce C. (Inventor)

    1993-01-01

    An articulated tang in clevis joint for incorporation in newly manufactured conventional strap-on orthotic knee devices or for replacing such joints in conventional strap-on orthotic knee devices is discussed. The instant tang in clevis joint allows the user the freedom to extend and bend the knee normally when no load (weight) is applied to the knee and to automatically lock the knee when the user transfers weight to the knee, thus preventing a damaged knee from bending uncontrollably when weight is applied to the knee. The tang in clevis joint of the present invention includes first and second clevis plates, a tang assembly and a spacer plate secured between the clevis plates. Each clevis plate includes a bevelled serrated upper section. A bevelled shoe is secured to the tank in close proximity to the bevelled serrated upper section of the clevis plates. A coiled spring mounted within an oblong bore of the tang normally urges the shoes secured to the tang out of engagement with the serrated upper section of each clevic plate to allow rotation of the tang relative to the clevis plate. When weight is applied to the joint, the load compresses the coiled spring, the serrations on each clevis plate dig into the bevelled shoes secured to the tang to prevent relative movement between the tang and clevis plates. A shoulder is provided on the tang and the spacer plate to prevent overextension of the joint.

  2. Exercise and the Knee Joint.

    ERIC Educational Resources Information Center

    Clarke, H. Harrison, Ed.

    1976-01-01

    This report by the President's Council on Physical Fitness and Sports examines the effects of various forms of physical exercise on the knee joint which, because of its vulnerability, is especially subject to injury. Discussion centers around the physical characteristics of the joint, commonly used measurements for determining knee stability,…

  3. New Generation Lockable Knee Brace

    NASA Technical Reports Server (NTRS)

    1996-01-01

    A knee brace that uses Space Shuttle propulsion technology has moved a step closer to being available to help knee injury and stroke patients and may possibly benefit patients with birth defects, spinal cord injuries, and post-polio conditions. After years of hard work, inventors at NASA's Marshall Space Flight Center (MSFC) in Huntsville, Alabama, have turned over the final design and prototype to industry partners at Horton's Orthotic Lab in Little Rock, Arkansas for further clinical testing. The device, called the Selectively Lockable Knee Brace, may mean faster, less painful rehabilitation for patients by allowing the knee to move when weight is not on the heel. Devices currently on the market lock the knee in a rigid, straight-leg position, or allow continuous free motion. Pictured here is a knee brace prototype being tested and fitted at Horton's Orthotic Lab. The knee brace is just one example of how space technology is being used to improve the lives of people on Earth. NASA's MSFC inventors Michael Shadoan and Neill Myers are space propulsion engineers who use the same mechanisms and materials to build systems for rockets that they used to design and develop the knee brace.

  4. An 11-year-old girl presenting with chronic knee pain: a case report with diagnostic dilemma.

    PubMed

    Maj, M Kamal; Ar, Abdul Halim; Faisal, Syed A; Ahmad, Johan; Das, Srijit

    2010-01-01

    Discoid meniscus is the commonest anatomical aberration of the knee joint, among rare cases such as bilateral separated lateral meniscus, accessory lateral meniscus, partial deficiency of the lateral meniscus and double-layered lateral meniscus. An 11-year-old girl presented with history of chronic pain in her right knee for the last 6 months. The problem disturbed her involvement in the sport activities at school. Clinical examination revealed a clicking sensation on knee extension with lateral joint line tenderness. Magnetic resonance imaging (MRI) of her right knee showed torn posterior horn of lateral meniscus. Arthroscopy examination revealed a discoid meniscus with absence posterior horn. Posterior horn deficient discoid meniscus is a rare form of a congenital meniscus anomaly. We as clinicians believe that the abnormal shaped meniscus may pose a diagnostic challenge clinically and radiologically. Presentation of this case may be beneficial for orthopaedicians in their daily clinical practice. PMID:21400986

  5. Metaphyseal bone loss in revision knee arthroplasty.

    PubMed

    Ponzio, Danielle Y; Austin, Matthew S

    2015-12-01

    The etiology of bone loss encountered during revision total knee arthroplasty (TKA) is often multifactorial and can include stress shielding, osteolysis, osteonecrosis, infection, mechanical loss due to a grossly loose implant, and iatrogenic loss at the time of implant resection. Selection of the reconstructive technique(s) to manage bone deficiency is determined by the location and magnitude of bone loss, ligament integrity, surgeon experience, and patient factors including the potential for additional revision, functional demand, and comorbidities. Smaller, contained defects are reliably managed with bone graft, cement augmented with screw fixation, or modular augments. Large metaphyseal defects require more extensive reconstruction such as impaction bone grafting with or without mesh augmentation, prosthetic augmentation, use of bulk structural allografts, or use of metaphyseal cones or sleeves. While each technique has advantages and disadvantages, the most optimal method for reconstruction of large metaphyseal bone defects during revision TKA is not clearly established. PMID:26362647

  6. 49 CFR 572.176 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 7 2012-10-01 2012-10-01 false Knees and knee impact test procedure. 572.176... Hybrid III 10-Year-Old Child Test Dummy (HIII-10C) § 572.176 Knees and knee impact test procedure. (a) The knee assembly for the purpose of this test is the part of the leg assembly shown in drawing...

  7. 49 CFR 572.166 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.166 Knees and knee impact test procedure. The knee assembly is assembled and tested as specified in 49 CFR 572.126 (Subpart N). ... 49 Transportation 7 2010-10-01 2010-10-01 false Knees and knee impact test procedure....

  8. 49 CFR 572.166 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.166 Knees and knee impact test procedure. The knee assembly is assembled and tested as specified in 49 CFR 572.126 (Subpart N). ... 49 Transportation 7 2011-10-01 2011-10-01 false Knees and knee impact test procedure....

  9. 49 CFR 572.176 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 7 2014-10-01 2014-10-01 false Knees and knee impact test procedure. 572.176... Hybrid III 10-Year-Old Child Test Dummy (HIII-10C) § 572.176 Knees and knee impact test procedure. (a) The knee assembly for the purpose of this test is the part of the leg assembly shown in drawing...

  10. 21 CFR 888.3570 - Knee joint femoral (hemi-knee) metallic uncemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Knee joint femoral (hemi-knee) metallic uncemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3570 Knee joint femoral (hemi-knee) metallic uncemented prosthesis. (a) Identification. A knee joint femoral...

  11. 49 CFR 572.166 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.166 Knees and knee impact test procedure. The knee assembly is assembled and tested as specified in 49 CFR 572.126 (Subpart N). ... 49 Transportation 7 2012-10-01 2012-10-01 false Knees and knee impact test procedure....

  12. 49 CFR 572.176 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false Knees and knee impact test procedure. 572.176... Hybrid III 10-Year-Old Child Test Dummy (HIII-10C) § 572.176 Knees and knee impact test procedure. (a) The knee assembly for the purpose of this test is the part of the leg assembly shown in drawing...

  13. 21 CFR 888.3570 - Knee joint femoral (hemi-knee) metallic uncemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Knee joint femoral (hemi-knee) metallic uncemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3570 Knee joint femoral (hemi-knee) metallic uncemented prosthesis. (a) Identification. A knee joint femoral...

  14. 49 CFR 572.166 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.166 Knees and knee impact test procedure. The knee assembly is assembled and tested as specified in 49 CFR 572.126 (Subpart N). ... 49 Transportation 7 2013-10-01 2013-10-01 false Knees and knee impact test procedure....

  15. 21 CFR 888.3570 - Knee joint femoral (hemi-knee) metallic uncemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Knee joint femoral (hemi-knee) metallic uncemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3570 Knee joint femoral (hemi-knee) metallic uncemented prosthesis. (a) Identification. A knee joint femoral...

  16. 49 CFR 572.166 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.166 Knees and knee impact test procedure. The knee assembly is assembled and tested as specified in 49 CFR 572.126 (Subpart N). ... 49 Transportation 7 2014-10-01 2014-10-01 false Knees and knee impact test procedure....

  17. 50 CFR 622.49 - Annual catch limits (ACLs) and accountability measures (AMs).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 12 2012-10-01 2012-10-01 false Annual catch limits (ACLs) and accountability measures (AMs). 622.49 Section 622.49 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE FISHERIES OF THE CARIBBEAN, GULF, AND SOUTH ATLANTIC Management Measures...

  18. 50 CFR 622.280 - Annual catch limits (ACLs) and accountability measures (AMs).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... MEXICO, AND SOUTH ATLANTIC Dolphin and Wahoo Fishery Off the Atlantic States § 622.280 Annual catch limits (ACLs) and accountability measures (AMs). (a) Atlantic dolphin—(1) Commercial sector. (i) If commercial landings for Atlantic dolphin, as estimated by the SRD, reach or are projected to reach...

  19. 50 CFR 622.280 - Annual catch limits (ACLs) and accountability measures (AMs).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... MEXICO, AND SOUTH ATLANTIC Dolphin and Wahoo Fishery Off the Atlantic States § 622.280 Annual catch limits (ACLs) and accountability measures (AMs). (a) Atlantic dolphin—(1) Commercial sector. If commercial landings for Atlantic dolphin, as estimated by the SRD, reach or are projected to reach...

  20. Evaluation of Proximal Joint Kinematics and Muscle Strength Following ACL Reconstruction Surgery in Female Athletes

    PubMed Central

    Noehren, Brian; Abraham, Autumn; Curry, Melisa; Johnson, Darren; Ireland, Mary Lloyd

    2015-01-01

    Background\\Purpose Despite the intense focus on outcomes following an anterior cruciate ligament (ACL) reconstruction, it is not yet known whether unresolved abnormal hip and trunk neuromuscular control exists. The purpose of this study was to compare trunk and hip kinematics during running, hip abductor and external rotator strength, and trunk control between females who had undergone an ACL reconstruction and healthy control participants. Methods We compared 20 ACL reconstructed females to 20 healthy individuals, measuring abduction and external rotation strength, a trunk control test, and performed an instrumented gait evaluation during running. Comparisons between groups were made for non-sagittal peak hip angles, forward trunk lean, trunk ipsilateral lean at initial contact, trunk control and hip abduction and external rotation strength. Results We found no significant differences in hip abduction (p = 0.25), hip external rotation strength (p = 0.63), peak hip adduction (p = 0.11) or hip internal rotation angle (p = 0.47). The ACL group did have a significantly greater ipsilateral trunk lean (p = 0.028), forward lean (p = 0.004), and had higher errors on the trunk stability test (p = 0.007). Conclusion We found significant differences in trunk control, suggesting further attention should be devoted to this component of rehabilitation. PMID:25044305

  1. ACL Report. A Report of the Activities of the American Classical League 1977-1978.

    ERIC Educational Resources Information Center

    Lawall, Gilbert

    Five topics of interest to persons involved in classical studies are discussed in this report: (1) "A Survey of the Classical Scene" focusses on the future of classical studies in elementary and secondary schools with some mention of the situation in colleges and universities. (2) "ACL: The State of the League" includes officers, agenda and…

  2. 50 CFR 648.64 - Yellowtail flounder sub-ACLs and AMs for the scallop fishery.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 12 2012-10-01 2012-10-01 false Yellowtail flounder sub-ACLs and AMs for the scallop fishery. 648.64 Section 648.64 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE FISHERIES OF THE...

  3. Pseudocyclops: two cases of ACL graft partial tears mimicking cyclops lesions on MRI.

    PubMed

    Simpfendorfer, Claus; Miniaci, Anthony; Subhas, Naveen; Winalski, Carl S; Ilaslan, Hakan

    2015-08-01

    Arthroscopic reconstruction of the anterior cruciate ligament (ACL) using autografts or allografts is a common surgical procedure, particularly in young athletes. Although the procedure has excellent success rates, complications such as mechanical impingement, graft rupture, and arthrofibrosis can occur, often necessitating additional surgery. Magnetic resonance (MR) imaging has become a valuable tool in evaluating complications after ACL reconstruction. We report two cases of ACL reconstruction complicated by arthroscopically proven partial graft tears. In both cases the torn anterior graft fibers were flipped into the intercondylar notch, mimicking anterior arthrofibrosis, i.e., a "cyclops lesion," on MR imaging. Careful review of the direction of graft fibers on MR imaging in the "pseudocyclops" lesions can help differentiate these partial tears from the fibrosis of a true cyclops. The "pseudocyclops" lesion is a previously undescribed MR imaging sign of partial ACL graft tear. Larger studies are required to determine the sensitivity and specificity of the sign, as well as the clinical importance of these partial graft tears. PMID:25620690

  4. Crises and Opportunities: The Futures of Scholarly Publishing. ACLS Occasional Paper, No. 57

    ERIC Educational Resources Information Center

    Alonso, Carlos J.; Davidson, Cathy N.; Unsworth, John M.; Withey, Lynne

    2003-01-01

    Presented herein are papers presented at a session entitled "Crises and Opportunities: The Future of Scholarly Publishing," from the American Council of Learned Societies (ACLS) Annual Meeting, May 10, 2003. Four speakers approached this topic from different standpoints: as leaders of learned societies, as senior university officials, from the…

  5. Medial and lateral segond fractures in a skeletally immature patient: a radiographic marker for the multiply injured knee.

    PubMed

    Kwon, Oh Soo; Park, Min Jung; Tjoumakaris, Fotios P

    2011-11-01

    Marginal fractures of the medial tibial plateau have been reported in the literature as a secondary type of Segond fracture. Some reports described this entity in the setting of combined injuries such as root avulsions of the medial meniscus, complete disruption of the posterior cruciate ligament (PCL), partial tear of the anterior cruciate ligament (ACL), and tears of the medial meniscus and medial collateral ligament. It has been postulated that medial marginal fractures are secondary to compression of the medial aspect of the femoral condyle and tibial plateau with a corresponding posterolateral corner injury. However, this mechanism of injury may not always be as straightforward.This article presents a case of an alternate injury pattern in a skeletally immature patient. A 16-year-old boy sustained a varus force and twisting injury to his knee, resulting in radiographic evidence of multiple avulsion fractures of the knee, including a fibular epiphyseal avulsion fracture and medial and lateral Segond fractures. Usually, the avulsion fractures serve as markers for significant ligamentous injuries in adult patients, but our patient had minimal injury to the PCL, ACL, and posterolateral corner. Further physical examination and imaging studies revealed an anterior horn root avulsion, meniscocapsular separation, and anterior cortical rim fracture. A combination of imaging modalities helped us further characterize the injury pattern to devise the optimal surgical plan, especially the fixation of the anterior cortical fracture of the tibia. PMID:22049962

  6. Prosthetic knee design by simulation

    SciTech Connect

    Hollerbach, K; Hollister, A

    1999-07-30

    Although 150,000 total knee replacement surgeries are performed annually in North America, current designs of knee prostheses have mechanical problems that include a limited range of motion, abnormal gait patterns, patellofemoral joint dysfunction, implant loosening or subsidence, and excessive wear. These problems fall into three categories: failure to reproduce normal joint kinematics, which results in altered limb function; bone-implant interface failure; and material failure. Modern computer technology can be used to design, prototype, and test new total knee implants. The design team uses the full range of CAD-CAM to design and produce implant prototypes for mechanical and clinical testing. Closer approximation of natural knee kinematics and kinetics is essential for improved patient function and diminished implant loads. Current knee replacement designs are based on 19th Century theories that the knee moves about a variable axis of rotation. Recent research has shown, however, that knee motion occurs about two fixed, offset axes of rotation. These aces are not perpendicular to the long axes of the bones or to each other, and the axes do not intersect. Bearing surfaces of mechanisms that move about axes of rotation are surfaces of revolution of those axes which advanced CAD technology can produce. Solids with surfaces of revolution for the two axes of rotation for the knee have been made using an HP9000 workstation and Structural Ideas Master Series CAD software at ArthroMotion. The implant's CAD model should closely replicate movements of the normal knee. The knee model will have a range of flexion-extension (FE) from -5 to 120 degrees. Movements include varus, valgus, internal and external rotation, as well as flexion and extension. The patellofemoral joint is aligned perpendicular to the FE axis and replicates the natural joint more closely than those of existing prostheses. The bearing surfaces will be more congruent than current designs and should

  7. Queen Alexandra's Knee.

    PubMed

    Pinals, Robert S

    2016-06-01

    In 1867, Alexandra, the 22-year-old Princess of Wales, late in her third pregnancy, had sudden onset of a febrile illness. There was a brief period of migratory arthritis, followed by persistent, severe inflammation in 1 knee. A diagnosis of rheumatic fever was made by her physicians, but the course of her illness differed greatly from the expected one. In this report reviewing her disorder, the suggestion is made that she more likely had gonococcal arthritis and that the infection was transmitted to her by her husband, the future King Edward VII, then known as "The Playboy Prince." PMID:27219308

  8. A Wearable Neuromuscular Device Reduces ACL Injury Risk in Female Soccer Athletes

    PubMed Central

    Decker, Michael John; Shaw, Matthew; Maddan, Casey; Campbell, Julie; Davidson, Bradley

    2016-01-01

    Objectives: Female soccer athletes have a three-fold greater risk of sustaining an ACL injury compared with their male counterparts yet only 1 in 5 teams engage in ACL risk reduction programs due to several participation barriers. The purpose of this study was to determine the effects of a wearable neuromuscular (WNM) device on postural control, performance and ACL injury risk in female soccer athletes. Methods: Seventy-nine elite youth and collegiate female soccer athletes (age range: 12-25 y) trained with a WNM device that applied bi-lateral, topical pressure to the medial quadriceps and hamstrings muscles (Topical Gear, Austin, TX). The athletes performed 7-9 weeks of pre-season training with the WNM device consisting of strength and conditioning exercises and on-field team practices (46-64 total hours of exposure). Postural control was measured in 15 athletes with and without the WNM device before and after the training program; and performance was measured in 25 athletes without the WNM device before and after the training program. Postural control was determined from a single-leg landing on a force plate from a horizontal distance normalized to leg length. The athletes were instructed to gain their balance as fast as possible upon landing and remain balanced for 5 seconds. The peak ground reaction forces (GRF) and the medial-lateral, anterior-posterior and net center of pressure (COP) velocities and displacement ranges were calculated during 2 seconds of single-leg stance. Performance measures including speed, power and endurance were measured from the 40 yard dash, vertical jump for height and the Beep test, respectively. A two-way repeated measures ANOVA and post-hoc comparisons were used to compare the postural variables; and t-tests were used to compare the performance tests (p=.05). ACL injury rates, the absolute risk reduction (ARR) and the number needed to treat (NNT) to prevent one ACL injury were calculated between the WNM intervention group and 11

  9. Diagnosis of knee injuries: comparison of the physical examination and magnetic resonance imaging with the findings from arthroscopy☆

    PubMed Central

    Orlando Júnior, Nilton; de Souza Leão, Marcos George; de Oliveira, Nelson Henrique Carvalho

    2015-01-01

    Objectives To ascertain the sensitivity, specificity, accuracy and concordance of the physical examination (PE) and magnetic resonance imaging (MRI) in comparison with arthroscopy, in diagnosing knee injuries. Methods Prospective study on 72 patients, with evaluation and comparison of PE, MRI and arthroscopic findings, to determine the concordance, accuracy, sensitivity and specificity. Results PE showed sensitivity of 75.00%, specificity of 62.50% and accuracy of 69.44% for medial meniscal (MM) lesions, while it showed sensitivity of 47.82%, specificity of 93.87% and accuracy of 79.16% for lateral meniscal (LM) lesions. For anterior cruciate ligament (ACL) injuries, PE showed sensitivity of 88.67%, specificity of 94.73% and accuracy of 90.27%. For MM lesions, MRI showed sensitivity of 92.50%, specificity of 62.50% and accuracy of 69.44%, while for LM injuries, it showed sensitivity of 65.00%, specificity of 88.46% and accuracy of 81.94%. For ACL injuries, MRI showed sensitivity of 86.79%, specificity of 73.68% and accuracy of 83.33%. For ACL injuries, the best concordance was with PE, while for MM and LM lesions, it was with MRI (p < 0.001). Conclusions Meniscal and ligament injuries can be diagnosed through careful physical examination, while requests for MRI are reserved for complex or doubtful cases. PE and MRI used together have high sensitivity for ACL and MM lesions, while for LM lesions the specificity is higher. Level of evidence II – Development of diagnostic criteria on consecutive patients (with universally applied reference “gold” standard). PMID:27218085

  10. Use of ultra-high molecular weight polycaprolactone scaffolds for ACL reconstruction.

    PubMed

    Leong, Natalie L; Kabir, Nima; Arshi, Armin; Nazemi, Azadeh; Jiang, Jie; Wu, Ben M; Petrigliano, Frank A; McAllister, David R

    2016-05-01

    Previously, we reported on the implantation of electrospun polycaprolactone (PCL) grafts for use in ACL tissue engineering in a small animal model. In the present study, we hypothesized that grafts fabricated from ultra-high molecular weight polycaprolactone (UHMWPCL) would have similarly favorable biologic properties but superior mechanical properties as compared to grafts fabricated from PCL. Two forms of polycaprolactone were obtained (UHMWPCL, MW = 500 kD, and PCL, MW = 80 kD) and electrospun into scaffolds that were used to perform ACL reconstruction in 7-8 week old male Lewis rats. The following groups were examined: UHMWPCL, PCL, flexor digitorum longus (FDL) allograft, native ACL, as well as sham surgery in which the ACL was transsected. At 16 weeks post-operatively, biomechanical testing, histology, and immunohistochemistry (IHC) were performed. Analysis of cellularity indicated that there was no significant difference among the UHMWPCL, PCL, and FDL allograft groups. Quantification of birefringence from picrosirius red staining demonstrated significantly more aligned collagen fibers in the allograft than the PCL group, but no difference between the UHMWPCL and allograft groups. The peak load to failure of the UHMWPCL grafts was significantly higher than PCL, and not significantly different from FDL allograft. This in vivo study establishes the superiority of the higher molecular weight version of polycaprolactone over PCL as a scaffold material for ACL reconstruction. By 16 weeks after implantation, the UHMWPCL grafts were not significantly different from the FDL allografts in terms of cellularity, peak load to failure, stiffness, and collagen fiber alignment. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:828-835, 2016. PMID:26497133

  11. Altered knee joint neuromuscular control during landing from a jump in 10-15 year old children with Generalised Joint Hypermobility. A substudy of the CHAMPS-study Denmark.

    PubMed

    Junge, Tina; Wedderkopp, Niels; Thorlund, Jonas Bloch; Søgaard, Karen; Juul-Kristensen, Birgit

    2015-06-01

    Generalised Joint Hypermobility (GJH) is considered an intrinsic risk factor for knee injuries. Knee neuromuscular control during landing may be altered in GJH due to reduced passive stability. The aim was to identify differences in knee neuromuscular control during landing of the Single-Leg-Hop-for-Distance test (SLHD) in 25 children with GJH compared to 29 children without GJH (controls), all 10-15years. Inclusion criteria for GJH: Beighton score⩾5/9 and minimum one hypermobile knee. EMG was recorded from the quadriceps, the hamstring and the calf muscles, presented relative to Maximum Voluntary Electrical activity (MVE). There was no difference in jump length between groups. Before landing, GJH had 33% lower Semitendinosus, but 32% higher Gastrocnemius Medialis activity and 39% higher co contraction of the lateral knee muscles, than controls. After landing, GJH had 36% lower Semitendinosus activity than controls, all significant findings. Although the groups performed equally in SLHD, GJH had a Gastrocnemius Medialis dominated neuromuscular strategy before landing, plausibly caused by reduced Semitendinosus activity. Reduced Semitendinosus activity was seen in GJH after landing, but with no compensatory Gastrocnemius Medialis activity. Reduced pre and post-activation of the Semitendinosus may present a risk factor for traumatic knee injuries as ACL ruptures in GJH with knee hypermobility. PMID:25801907

  12. Unicompartmental knee arthroplasty

    PubMed Central

    Murray, D. W.; Liddle, A. D.; Dodd, C. A. F.; Pandit, H.

    2015-01-01

    There is a large amount of evidence available about the relative merits of unicompartmental and total knee arthroplasty (UKA and TKA). Based on the same evidence, different people draw different conclusions and as a result, there is great variability in the usage of UKA. The revision rate of UKA is much higher than TKA and so some surgeons conclude that UKA should not be performed. Other surgeons believe that the main reason for the high revision rate is that UKA is easy to revise and, therefore, the threshold for revision is low. They also believe that UKA has many advantages over TKA such as a faster recovery, lower morbidity and mortality and better function. They therefore conclude that UKA should be undertaken whenever appropriate. The solution to this argument is to minimise the revision rate of UKA, thereby addressing the main disadvantage of UKA. The evidence suggests that this will be achieved if surgeons use UKA for at least 20% of their knee arthroplasties and use implants that are appropriate for these broad indications. Cite this article: Bone Joint J 2015;97-B(10 Suppl A):3–8. PMID:26430080

  13. Reconstruction of knee joint soft tissue and patellar tendon defects using a composite anterolateral thigh flap with vascularized fascia lata.

    PubMed

    Kuo, Yur-Ren; An, Po-Chung; Kuo, Mei-Hui; Kueh, Nai-Siong; Yao, Sheng-Fa; Jeng, Seng-Feng

    2008-01-01

    Reconstruction of a complex knee trauma with knee joint exposure and composite soft tissue and patellar tendon deficiency remains a challenging task. Multiple-stage reconstruction is time-consuming and produces considerable suffering for patients. Early mobilization following knee reconstruction has achieved good outcomes. Herein, we reported one-stage reconstruction with an ALT myocutaneous flap with vascularized fascia lata was utilized for one patient with a large complex knee joint soft tissue defect, and segmental deficiency of the patellar tendon. The fascia lata sheet was rolled to mimic a patellar tendon. The exposed knee joint was obturated by the vastus lateralis muscle of the ALT myocutaneous flap. The skin and soft tissue defect was reconstructed using the skin paddle of the ALT flap. The patient's postoperative course was uneventful. An MRI examination demonstrated good continuity of the reconstructed patellar tendon. The active ROM of the injured knee reached 100 degrees (extension deficiency 20 degrees and flexion 120 degrees ) at 5 years. Objective functional assessment of the patella-femoral joint utilized a kinetic communicator machine (Kin-Com 500H, Chattecx, Chattanooga, TN, USA) revealed still mild extension insufficiency. However, the patient reported that he was able to perform normal daily activities without difficulty at 5-year follow-up. PMID:18215803

  14. Osteonecrosis of the knee: review

    PubMed Central

    Karim, Ammar R.; Cherian, Jeffrey J.; Jauregui, Julio J.; Pierce, Todd

    2015-01-01

    Osteonecrosis is a devastating disease that can lead to end-stage arthritis of various joint including the knee. There are three categories of osteonecrosis that affect the knee: spontaneous osteonecrosis of the knee (SONK), secondary, and post-arthroscopic. Regardless of osteonecrosis categories, the treatment of this disease aims to halt further progression or delay the onset of end-stage arthritis of the knee. However, once substantial joint surface collapse has occurred or there are sign of degenerative arthritis, joint arthroplasty is the most appropriate treatment option. Currently, the non-operative treatment options consist of observation, non-steroidal anti-inflammatory drugs (NSAIDs), protected weight bearing, and analgesia as needed. Operative interventions include joint preserving surgery, unilateral knee arthroplasty (UKA), or total knee arthroplasty (TKA) depending on the extent and type of disease. Joint preserving procedures (i.e., arthroscopy, core decompression, osteochondral autograft, and bone grafting) are usually attempted in pre-collapse and some post-collapse lesions, when the articular cartilage is generally intact with only the underlying subchondral bone being affected. Conversely, after severe subchondral collapse has occurred, procedures that attempt to salvage the joint are rarely successful and joint arthroplasty are necessary to relieve pain. The purpose of this article is to highlight the recent evidence concerning the treatment options across the spectrum of management of osteonecrosis of the knee including lesion observation, medications, joint preserving techniques, and total joint arthroplasties. PMID:25705638

  15. New Generation Lockable Knee Brace

    NASA Technical Reports Server (NTRS)

    2000-01-01

    A knee brace that uses Space Shuttle propulsion technology has moved a step closer to being available to help knee injury and stroke patients and may possibly benefit patients with birth defects, spinal cord injuries, and post-polio conditions. After years of hard work, inventors at NASA's Marshall Space Flight Center (MSFC) in Huntsville, Alabama, have turned over the final design and prototype to industry partners at Horton's Orthotic Lab in Little Rock, Arkansas for further clinical testing. The device, called the Selectively Lockable Knee Brace, may mean faster, less painful rehabilitation for patients by allowing the knee to move when weight is not on the heel. Devices currently on the market lock the knee in a rigid, straight-leg position, or allow continuous free motion. The knee brace is just one example of how space technology is being used to improve the lives of people on Earth. NASA's MSFC inventors Michael Shadoan and Neill Myers are space propulsion engineers who use the same mechanisms and materials to build systems for rockets that they used to design and develop the knee brace.

  16. Chronic Changes in the Articular Cartilage and Meniscus Following Traumatic Impact to the Lapine Knee

    PubMed Central

    Fischenich, Kristine M.; Button, Keith D.; Coatney, Garrett A.; Fajardo, Ryan S.; Leikert, Kevin M.; Haut, Roger C.; Haut Donahue, Tammy L.

    2014-01-01

    The objective of this study was to induce anterior cruciate ligament (ACL) and meniscal damage, via a single tibiofemoral compressive impact, in order to document articular cartilage and meniscal changes post impact. Tibiofemoral joints of Flemish Giant rabbits were subjected to a single blunt impact that ruptured the ACL and produced acute meniscal damage. Animals were allowed unrestricted cage activity for 12 weeks before euthanasia. India ink analysis of the articular cartilage revealed higher degrees of surface damage on the impacted tibias (p=0.018) and femurs (p<0.0001) compared to controls. Chronic meniscal damage was most prevalent in the medial central and medial posterior regions. Mechanical tests revealed an overall 19.4% increase in tibial plateau cartilage thickness (p=0.026), 34.8% increase in tibial plateau permeability (p=0.054), 40.8% increase in femoral condyle permeability (p=0.029), and 20.1% decrease in femoral condyle matrix modulus (p=0.012) in impacted joints compared to controls. Both the instantaneous and equilibrium moduli of the lateral and medial menisci were decreased compared to control (p<0.02). Histological analyses revealed significantly increased presence of fissures in the medial femur (p = 0.036). In both the meniscus and cartilage there was a significant decrease in GAG coverage for the impacted limbs. Based on these results it is clear that an unattended combined meniscal and ACL injury results in significant changes to the soft tissues in this experimental joint 12 weeks post injury. Such changes are consistent with a clinical description of mid to late stage PTOA of the knee. PMID:25523754

  17. Alpha-1 Antitrypsin Deficiency

    MedlinePlus

    ... Liver Disease Information > Alpha-1 Antitrypsin Deficiency Alpha-1 Antitrypsin Deficiency Explore this section to learn more about alpha-1 antitrypsin deficiency, including a description of the disorder ...

  18. Predictors of bone loss in revision total knee arthroplasty.

    PubMed

    Bloomfield, Michael R; Klika, Alison K; Lee, Ho H; Joyce, David M; Mehta, Priyesh; Barsoum, Wael K

    2010-03-01

    Revision total knee arthroplasty (RTKA) requires preoperative planning to enable the reconstruction of bony deficiencies. The objective of this project was to identify predictors of bone loss management at RTKA based on the preoperative failure mode and patient demographics known preoperatively. We retrospectively reviewed 245 consecutive RTKA procedures in which the same revision knee system was utilized. Patient demographic and treatment data were recorded, and locations of bone loss were identified based on the reconstructive management. We identified significant predictors for use of femoral augments at all four positions. Several predictors significantly predisposed to use of a thick (>19 mm) polyethylene; however, no predictors of tibial augments were significant. Although the reconstruction of bone loss is primarily based on the intraoperative assessment, these findings may provide additional information to help the surgeon prepare for difficult revision procedures. PMID:20812582

  19. Comparison of hip and knee muscle moments in subjects with and without knee pain.

    PubMed

    Manetta, Jennifer; Franz, Laura Hayden; Moon, Chris; Perell, Karen L; Fang, Meika

    2002-12-01

    Elderly subjects with and without knee pain walked at a comfortable pace during gait analysis. Comparison of peak hip and knee internal extensor generalized muscle moments (GMMs) during loading response was made between groups. Walking velocity, peak hip internal extensor GMM, and knee range of motion (ROM) were significantly less for the group with knee pain than for the group without pain. Peak hip internal extensor GMM was strongly correlated with velocity, but peak knee internal extensor GMM was not. Knee ROM limitations may account for the increased peak knee internal extensor GMM in the knee pain group. PMID:12443949

  20. Chronic anterolateral instability of the knee. A roentgen stereophotogrammetric evaluation.

    PubMed

    Kärrholm, J; Elmqvist, L G; Selvik, G; Hansson, L I

    1989-01-01

    The rotatory stability of the knee was investigated in 20 patients with a previous tear of the ACL. The three-dimensional movements of the tibia during the testing procedure were registered using roentgen stereophotogrammetric analysis. Changes of the tibial movements between an intermediate, an anterior, or a posterior tibial position were registered using tibial tractions in combination with a simultaneous external or internal rotatory torque. At 20 degrees of flexion the internal rotatory laxity was increased on the injured side. The external rotatory laxity did not significantly differ between the two sides. With anterior traction, the internal rotatory laxity increased on both the injured and the normal sides and became almost equal. The external rotatory laxity manifested a decrease which was most pronounced on the injured side. With posterior traction, the rotatory laxities decreased and did not significantly differ between the two sides. Analysis of the simultaneously occurring translations of the tibial plateau disclosed abnormal displacements of both the medial and the lateral tibial condyles on the injured side. PMID:2782540

  1. Cosmetic effect of knee joint in a knee disarticulation prosthesis.

    PubMed

    de Laat, Fred A; van der Pluijm, Mark J; van Kuijk, Annette A; Geertzen, Jan H; Roorda, Leo D

    2014-01-01

    Despite numerous advantages, knee disarticulations (KDs) are rarely performed because of the anticipated KD prosthesis fitting problems that include the positioning of the knee joint distally from the KD socket. This results in lengthening of the thigh and subsequent shortening of the shank. The objective of this study was to assess the cosmetic effect of the knee joint in a KD prosthesis by determining the extent of the lengthening of the thigh and the shortening of the shank. This lengthening and shortening were measured through an experimental setup using laser techniques. These measurements were made of 18 knee joints used in KD prostheses. Lengthening of the thigh varied between 23 and 92 mm, and shortening of the shank varied between 3 and 50 mm. The polycentric knees Medi KH6 and Medi KHF1 showed the least lengthening of the thigh, and the polycentric knees Teh Lin Prosthetic & Orthotic Co. Ltd Graph-Lite and Medi KP5 showed the least shortening of the shank. PMID:25856500

  2. Use of Supercritical Sterilized Bone Allograft in Two Stage Revision ACL Reconstruction

    PubMed Central

    Roe, Justin; Rutten, Sjoerd; Bonnar, Fiona; Salmon, Lucy; Pinczewski, Leo

    2016-01-01

    Objectives: Revision ACL-reconstruction can be compromised by bone loss as result of tunnel widening or poorly placed tunnels. Two-stage revision ACL consist of initial removal of the old fixation hardware and remaining ACL-graft tissue, followed by bone grafting of the tunnels. After a period of graft incorporation and bone remodeling, an ACL-reconstruction is performed. Our primary aim is to examine the use of supercritical carbon dioxide sterilized bone allograft for tunnel grafting in order to determine the bone quality, graft incorporation and remodeling, by using histology and histomorphometric analysis. Secondarily, we aimed to determine whether the histological findings correlate with the timing of the second stage revision procedure. Methods: Case Series. 12 subjects underwent 2-stage revision ACL reconstruction. Femoral and tibial tunnels were bone grafted with supercritical carbon dioxide sterilized bone allograft (Australian Biotechnologies). Mean time from bone grafting to 2nd stage was 8.8 months (range, 5.6 to 21.3 months). Bone biopsies were taken at the time of the 2nd surgery and decalcified and embedded in paraffin. Sections were hematoxylin and eosin stained for microscopic analysis. Results: The graft material was easily identified by its necrotic appearance with empty osteocytes lacunes within the lamellar trabecular bone. In all tissue samples predominately lamellar host bone apposition was seen on the surface of graft fragments known as creeping substitution. Separate bone graft fragments were bridged by newly formed woven bone. In the histological sections of 2 subjects some small islands of chondral cell differentiation were seen, which may relate to endochondral ossification. Active bone remodeling and resorption through combined osteoclastic and osteoblastic activity was present in 2 subjects (7.0 and 6.3 months post grafting), suggesting more advanced phases of graft incorporation. Mean bone volume was 68% over tissue volume (range 33

  3. Ochronosis of the knee with secondary osteoarthritis requiring total knee replacement in a patient with cryptogenic organising pneumonia.

    PubMed

    Jasper, Jorrit; Metsaars, Wieneke; Jansen, Joris

    2016-01-01

    Ochronosis is a rare autosomal recessive metabolic disease caused by homogentisic acid oxidase enzyme deficiency. High homogentisic acid levels will eventually result in black deposits in skin, sclerae, connective tissues and urine (alkaptonuria). It can lead to early degeneration of connective tissues and cartilage. Ochronosis can damage normal cartilage, leading to secondary osteoarthritis. The diagnosis is often delayed because of its low prevalence and non-specific early symptoms. In our patient, the secondary osteoarthritis due to ochronosis deposits in the cartilage was treated by total knee arthroplasty, with good clinical outcome. This article reports the first case of ochronosis with secondary osteoarthritis of the knee in a patient previously diagnosed with cryptogenic organising pneumonia (COP). PMID:27207988

  4. Intraarticular osteochondroma of the knee

    PubMed Central

    Morey, Vivek Morey; Jalan, Divesh; Mittal, Ravi; Gamangatti, Shivanand

    2014-01-01

    Osteochondromas are usually extra articular and grow away from the joint towards the diaphysis. Intraarticular osteochondromas are very rare and often misdiagnosed. We report a case of 16-year-old boy who presented with pain and clicking sound in the right knee for last 6 months. On examination, click was felt at the terminal flexion of the knee. The lateral radiograph of the right knee showed a radio opaque shadow at the posterior aspect of the distal end of femur, which was further evaluated with an MRI. Arthroscopy showed a hard lesion arising from the roof of the intercondylar notch of femur. It was excised arthroscopically. Histopathology revealed it to be an osteochondroma. Thus, intraarticular osteochondroma of the knee can be considered as a rare cause of pain in young patients. PMID:24932044

  5. Anterior Knee Pain (Chondromalacia Patellae).

    ERIC Educational Resources Information Center

    Garrick, James G.

    1989-01-01

    This article presents a pragmatic approach to the definition, diagnosis, and management of anterior knee pain. Symptoms and treatment are described. Emphasis is on active involvement of the patient in the rehabilitation exercise program. (IAH)

  6. Minimally Invasive Total Knee Arthroplasty

    MedlinePlus

    ... and drill her. And how much are you rotating there? This rotates 3 degrees externally with respect ... femoral components that can be used. With the rotating knee system, a class III device at this ...

  7. Knee Brace Would Lock And Unlock Automatically

    NASA Technical Reports Server (NTRS)

    Myers, Neill; Forbes, John; Shadoan, Mike; Baker, Kevin

    1995-01-01

    Proposed knee brace designed to aid rehabilitation of person who suffered some muscle damage in leg. Not limited to locking in straight-leg position and, instead, locks at any bend angle. Does not prevent knee from bearing weight. Instead, knee brace allows knee to bear weight and locks only when foot and lower leg bear weight. Thus, brace prevents flexion that wearer desired to prevent but could not prevent because of weakened muscles. Knee bends freely to exercise knee-related muscles. Knee brace strapped at upper end to leg above knee, and anchored at lower end by stirrup under foot. Joint mechanism (identical mechanisms used in left and right assemblies) allows knee joint to flex freely except when weight applied to heel.

  8. Analysis of Joint Sounds in the Diagnosis of Knee Disorders

    ClinicalTrials.gov

    2015-07-22

    Healthy Patients; No Knee Complaints; No Knee Injuries; No Knee Surgeries; No Neurological Problems; Patients Undergoing Knee Arthroscopy, Who Has a Pre-op MRI; Age Groups of 20,40 and 60 Years of Age.

  9. 50 CFR 622.411 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... OF THE CARIBBEAN, GULF OF MEXICO, AND SOUTH ATLANTIC Spiny Lobster Fishery of the Gulf of Mexico and... measures (AMs). For recreational and commercial spiny lobster landings combined, the ACL is 7.32 million...

  10. 50 CFR 622.411 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... OF THE CARIBBEAN, GULF OF MEXICO, AND SOUTH ATLANTIC Spiny Lobster Fishery of the Gulf of Mexico and... measures (AMs). For recreational and commercial spiny lobster landings combined, the ACL is 7.32 million...

  11. Effect of Preoperative Vitamin D Levels on Functional Performance after Total Knee Arthroplasty

    PubMed Central

    Patil, Aniket Machindra; Maniar, Adit Rajesh; Gangaraju, Bharat; Singh, Jaivardhan

    2016-01-01

    Background Low vitamin D levels affects muscle function. Vitamin D and calcium deficiency cause osteomalacic myopathy and poor functional recovery after hip fractures. The relationship of vitamin D and functional performance after total knee arthroplasty (TKA) is not previously reported. Methods Influence of vitamin D on functional performance before and after TKA was reviewed retrospectively in 120 patients. Of these, 64 had vitamin D deficiency (25-hydroxy vitamin D < 30 ng/mL) preoperatively. All 120 patients received vitamin D oral supplementation postoperatively. Functional parameters including Western Ontario and McMaster Osteoarthritis Index (WOMAC), Short-Form Health Survey questionnaire, and Knee Society Score were assessed pre- and postoperatively at 3 months. Results Preoperative function was significantly lower in osteoarthritic patients with vitamin D deficiency (WOMAC score; p = 0.040), but at 3 months all functional scores were similar. Conclusions We concluded that vitamin D deficiency has a negative effect on function in knee osteoarthritic patients. However, postoperative vitamin D supplementation can lead to functional recovery in these patients. Thus, TKA should not be delayed in vitamin D deficient patients; rather supplementation in the postoperative period is preferable to achieve comparable functional outcome at 3 months to patients with vitamin D sufficiency. PMID:27247739

  12. Results of meniscectomy and meniscal repair in anterior cruciate ligament reconstruction

    PubMed Central

    DELEDDA, DAVIDE; ROSSO, FEDERICA; COTTINO, UMBERTO; BONASIA, DAVIDE EDOARDO; ROSSI, ROBERTO

    2015-01-01

    Meniscal tears are commonly associated with anterior cruciate ligament (ACL) injuries. A deficient medial meniscus results in knee instability and could lead to higher stress forces on the ACL reconstruction. Comparison of results in meniscectomy and meniscal repairs revealed worse clinical outcomes in meniscectomy, but higher re-operation rates in meniscal repairs. Our aim was to review the results of ACL reconstruction associated with meniscectomy or meniscal repair. PMID:26889472

  13. THE ROLE AND IMPLEMENTATION OF ECCENTRIC TRAINING IN ATHLETIC REHABILITATION: TENDINOPATHY, HAMSTRING STRAINS, AND ACL RECONSTRUCTION

    PubMed Central

    Reiman, Michael

    2011-01-01

    The benefits and proposed physiological mechanisms of eccentric exercise have previously been elucidated and eccentric exercise has been used for well over seventy years. Traditionally, eccentric exercise has been used as a regular component of strength training. However, in recent years, eccentric exercise has been used in rehabilitation to manage a host of conditions. Of note, there is evidence in the literature supporting eccentric exercise for the rehabilitation of tendinopathies, muscle strains, and in anterior cruciate ligament (ACL) rehabilitation. The purpose of this Clinical Commentary is to discuss the physiologic mechanism of eccentric exercise as well as to review the literature regarding the utilization of eccentric training during rehabilitation. A secondary purpose of this commentary is to provide the reader with a framework for the implementation of eccentric training during rehabilitation of tendinopathies, muscle strains, and after ACL reconstruction. PMID:21655455

  14. The Effects of Age and Platelet-Rich Plasma on ACL Cell Viability and Collagen Gene Expression

    PubMed Central

    Cheng, M.Y; Johnson, V.M.; Murray, M. M.

    2011-01-01

    Platelet-rich plasma (PRP) has shown in vivo potential to stimulate anterior cruciate ligament (ACL) healing at early time points in large animal models. However, in animal models, the healing potential of the ACL is dependent on animal age. In this study, we hypothesized that there are age-dependent differences in ACL cell metabolism, collagen gene expression and the ability of the cells to respond to growth factors in platelet-rich plasma (PRP). To test this hypothesis, ACL cells were obtained from skeletally immature, adolescent and adult pigs and cultured in a collagen type I hydrogel with or without PRP for 14 days. When cultured in collagen-only hydrogel, ACL cells from adult pigs had a 19% lower apoptotic rate as compared to immature pigs (p=0.001) and a 25% higher cellular metabolic activity as compared to adolescent pigs (p=0.006). The addition of PRP to the collagen hydrogel resulted in a significantly increased cellular metabolic activity, reduced apoptotic rate and stimulation of collagen production in the cells from the immature and adolescent animals (p<0.05 for all comparisons) but had less of an effect on adult cells. These findings suggest that skeletal maturity may influence ACL cells’ metabolic activity, apoptosis, collagen production, and response to PRP. PMID:21748791

  15. Changes in knee kinematics following total knee arthroplasty.

    PubMed

    Akbari Shandiz, Mohsen; Boulos, Paul; Saevarsson, Stefan Karl; Yoo, Sam; Miller, Stephen; Anglin, Carolyn

    2016-04-01

    Total knee arthroplasty (TKA) changes the knee joint in both intentional and unintentional, known and unknown, ways. Patellofemoral and tibiofemoral kinematics play an important role in postoperative pain, function, satisfaction and revision, yet are largely unknown. Preoperative kinematics, postoperative kinematics or changes in kinematics may help identify causes of poor clinical outcome. Patellofemoral kinematics are challenging to record since the patella is obscured by the metal femoral component in X-ray and moves under the skin. The purpose of this study was to determine the kinematic degrees of freedom having significant changes and to evaluate the variability in individual changes to allow future study of patients with poor clinical outcomes. We prospectively studied the 6 degrees of freedom patellofemoral and tibiofemoral weightbearing kinematics, tibiofemoral contact points and helical axes of rotation of nine subjects before and at least 1 year after total knee arthroplasty using clinically available computed tomography and radiographic imaging systems. Normal kinematics for healthy individuals were identified from the literature. Significant differences existed between pre-TKA and post-TKA kinematics, with the post-TKA kinematics being closer to normal. While on average the pre-total knee arthroplasty knees in this group displayed no pivoting (only translation), individually only five knees displayed this behaviour (of these, two showed lateral pivoting, one showed medial pivoting and one showed central pivoting). There was considerable variability postoperatively as well (five central, two lateral and two medial pivoting). Both preop and postop, flexion behaviour was more hinge-like medially and more rolling laterally. Helical axes were more consistent postop for this group. An inclusive understanding of the pre-TKA and post-TKA kinematics and changes in kinematics due to total knee arthroplasty could improve implant design, patient diagnosis and

  16. Tibial tunnel widening after bioresorbable poly-lactide calcium carbonate interference screw usage in ACL reconstruction.

    PubMed

    Foldager, Casper; Jakobsen, Bent W; Lund, Bent; Christiansen, Svend Erik; Kashi, Lotte; Mikkelsen, Lone R; Lind, Martin

    2010-01-01

    Developing bio-absorbable interference screws for anterior cruciate ligament (ACL) reconstruction has proven to be a challenging task. The aim of this study was to investigate the osteogenetic response of poly-lactide carbonate (PLC) interference screws in ACL reconstruction in humans. Ten patients (median age, 28 years) underwent arthroscopic ACL reconstruction with semitendinosus/gracilis tendon graft and a PLC interference screw. The patients were scanned with a multi-slice CT scanner 2 weeks and 1 year postoperatively. Fourteen days postoperatively a mean tunnel widening of 78% [52%; 110%] was observed. At 1-year follow-up, the mean tunnel widening was 128% [84%; 180%]. No sign of bone replacement or bone ingrowth was observed. Factors such as accelerated rehabilitation, micro-motions, and early screw degradation might be responsible for this large tunnel widening. Our results demonstrate the difficulty in translation of preclinical data. This study illustrates the need for extensive preclinical investigation of new materials for clinical purposes. PMID:19609505

  17. Intra-articular bupivacaine or bupivacaine and morphine after ACL reconstruction

    PubMed Central

    Danieli, Marcus Vinicius; Cavazzani Neto, Antonio; Herrera, Paulo Adilson

    2012-01-01

    Objective Reconstructive surgery of the ACL is one of the most commonly performed surgeries today and the control of postoperative pain is part of the priorities of the surgeon. Within the arsenal of analgesia we have the intra-articular application of drugs, and the most studied one is bupivacaine with or without morphine. This study compared the application of bupivacaine with or without morphine with a control group after ACL reconstruction with flexor tendon graft. Methods Forty-five patients were randomized into three groups: in group I, 20 ml of saline were applied intra-articularly at the end of the surgery; in group II, 20 ml of bupivacaine 0.25%; and in group III, bupivacaine 0.25% associated with 1 mg of morphine. The groups were assessed for degree of pain by the Visual Analog Scale at 6, 24 and 48 hours postoperatively. Results Group III had less pain at all times, but the pain was not as intense in all groups to the point of needing extra medications beyond the established protocol. Conclusion The intra-articular application of these medications after ACL reconstruction with flexor tendon graft when performed under spinal anesthesia is not useful enough to use regularly. Level of Evidence II, Lesser quality RCT PMID:24453613

  18. MRI Evaluation of Patella Alignment Before and After Anatomical Reconstruction of ACL Undergoing Unified Rehabilitation Programme Introduced by CMC Physical Therapy Team

    PubMed Central

    Straszewski, Dariusz; Plenzler, Marcin; Szczepaniak, Joanna; Śmigielski, Robert; Ciszkowska-Łysoń, Beata; Popieluch, Marcin; Kopko, Szymon

    2014-01-01

    Objectives: The aim of the study was to asses the impact of the functional rehabilitation on patella alignment with MRI imaging in patients who underwent the ACL reconstruction. The surgical approach with the use of patellar tendon graft is known to carry the risk of lowering patella height (patella baja), which, in turn, may lead to accelerated cartilage wear in patellofemoral joint. Methods: 30 patients after the anatomical reconstruction of ACL took part in this study (23 male, and 7 female, mean age = 28 ± 10,6 years). During the procedure a patellar tendon graft was used. The Insali-Salvati ratio measured with MRI (images taken pre-procedural, and 9 months after the surgery) was used for the assessment of patellar alignment. The measurements were taken by one radiology specialist on MRI scans in sagittal view in PD sequence. During the examination, patellar joint was in flexion (approx.10 degrees). As the point of reference for patella’s position ISR ratio was in the range of 0.8 - 1.2. All patients were operated on by the same team of surgeons and underwent an unified rehabilitation programme led by a team of selected physiotherapists. The main features of the programme were: an early muscle activation (second day after the procedure); mobilisation of the patella and tissues of the anterior compartment of the knee; weight bearing co-contraction exercises, and the sensomotoric training of the entire kinetic chain of the lower limb. The data recorded was statistically analysed using the Wilcoxon signed-rank test in order to establish parameters’ changes within the study group.. Results: The mean ISR value before the procedure was 0.84 (± 0,1), whereas 9 months after the surgery it was 0.85 (± 0,1). The results’ analysis did not show any statistically significant changes between ISR values. Nine months after the procedure patella baja has not been observed in any of the evaluated patients. Conclusion: The functional rehabilitation programme designed by

  19. Synovial effusions at the knee as the inaugural manifestation of stress fracture of the proximal tibia.

    PubMed

    Lassoued, S; Billey, T

    1996-01-01

    Eight patients with an age ranging from 72 to 83 years, seen in an outpatient clinic over a one-year period for stress fractures of the proximal tibia responsible for acute knee pain and effusion were studied retrospectively. Plain roentgenograms were often normal at presentation but subsequently showed sclerosis of the proximal tibia. Radionuclide bone scanning was the most useful investigation for early diagnosis. Potential risk factors were advanced: age, genu varum or valgum, overweight and vitamin D deficiency. Stress fracture of the proximal tibia should be considered in elderly patients with knee pain, effusion and normal roentgenograms. Elimination of weight-bearing ensures healing of the fracture. PMID:9064115

  20. PGK deficiency.

    PubMed

    Beutler, Ernest

    2007-01-01

    Phosphoglycerate kinase (PGK) deficiency is one of the relatively uncommon causes of hereditary non-spherocytic haemolytic anaemia (HNSHA). The gene encoding the erythrocyte enzyme PGK1, is X-linked. Mutations of this gene may cause chronic haemolysis with or without mental retardation and they may cause myopathies, often with episodes of myoglobinuria, or a combination of these clinical manifestations. Twenty-six families have been described and in 20 of these the mutations are known. The reason for different clinical manifestations of mutations of the same gene remains unknown. PMID:17222195

  1. PATIENT-SPECIFIC AND SURGERY-SPECIFIC FACTORS THAT AFFECT RETURN TO SPORT AFTER ACL RECONSTRUCTION

    PubMed Central

    Lynch, Andrew; Rabuck, Stephen; Lynch, Brittany; Davin, Sarah; Irrgang, James

    2016-01-01

    Context Anterior cruciate ligament (ACL) reconstruction is frequently performed to allow individuals to return to their pre-injury levels of sports participation, however, return to pre-injury level of sport is poor and re-injury rates are unacceptably high. Re-injury is likely associated with the timeframe and guidelines for return to sport (RTS). It is imperative for clinicians to recognize risk factors for re-injury and to ensure that modifiable risk factors are addressed prior to RTS. The purpose of this commentary is to summarize the current literature on the outcomes following return to sport after ACL reconstruction and to outline the biologic and patient-specific factors that should be considered when counseling an athlete on their progression through rehabilitation. Evidence Acquisition A comprehensive literature search was performed to identify RTS criteria and RTS rates after ACL reconstruction with consideration paid to graft healing, anatomic reconstruction, and risk factors for re-injury and revision. Results were screened for relevant original research articles and review articles, from which results were summarized. Study Design Clinical Review of the Literature Results Variable RTS rates are presented in the literature due to variable definitions of RTS ranging from a high threshold (return to competition) to low threshold (physician clearance for return to play). Re-injury and contralateral injury rates are greater than the risk for primary ACL injury, which may be related to insufficient RTS guidelines based on time from surgery, which do not allow for proper healing or resolution of post-operative impairments and elimination of risk factors associated with both primary and secondary ACL injuries. Conclusions RTS rates to pre-injury level of activity after ACLR are poor and the risk for graft injury or contralateral injury requiring an additional surgery is substantial. Resolving impairments while eliminating movement patterns associated with

  2. Utilization of Modified NFL Combine Testing to Identify Functional Deficits in Athletes Following ACL Reconstruction

    PubMed Central

    MYER, GREGORY D.; SCHMITT, LAURA C.; BRENT, JENSEN L.; FORD, KEVIN R.; BARBER FOSS, KIM D.; SCHERER, BRADLEY J.; HEIDT, ROBERT S.; DIVINE, JON G.; HEWETT, TIMOTHY E.

    2012-01-01

    STUDY DESIGN Case control. OBJECTIVES To use modified NFL Combine testing methodology to test for functional deficits in athletes following anterior cruciate ligament (ACL) reconstruction following return to sport. BACKGROUND There is a need to develop objective, performance-based, on-field assessment methods designed to identify potential lower extremity performance deficits and related impairments in this population. METHODS Eighteen patients (mean ± SD age, 16.9 ± 2.1 years; height, 170.0 ± 8.7 cm; body mass, 71.9 ± 21.8 kg) who returned to their sport within a year following ACL reconstruction (95% CI: 7.8 to 11.9 months from surgery) participated (ACLR group). These individuals were asked to bring 1 or 2 teammates to serve as control participants, who were matched for sex, sport, and age (n = 20; mean ± SD age, 16.9 ± 1.1 years; height, 169.7 ± 8.4 cm; body mass, 70.1 ± 20.7 kg). Functional performance was tested using the broad jump, vertical jump, modified long shuttle, modified pro shuttle, modified agility T-test, timed hop, triple hop, single hop, and crossover hop tests. A 1-way multivariate analysis of variance (MANOVA) was used to evaluate group differences for dependent performance variables. RESULTS The functional performance measurements of skills requiring bilateral involvement of both lower extremities showed no group differences between the ACLR and control groups (P>.05). An overall group difference (P = .006) was observed for the combined limb symmetry index (LSI) measures. However, the modified double-limb performance tasks (long shuttle, modified agility T-test, and pro shuttle) were not, independently, sufficiently sensitive to detect limb deficits in individuals with ACL reconstruction. Conversely, the LSI on the distance measures of the single-limb performance tasks all provided moderate to large effect sizes to differentiate between the ACLR and control groups, as the individuals who had ACL reconstruction demonstrated involved

  3. Will 'Unloading' Shoes Help Your Arthritic Knees?

    MedlinePlus

    ... 160406.html Will 'Unloading' Shoes Help Your Arthritic Knees? Study puts specially designed footwear to the test ... 2016 (HealthDay News) -- For reducing pain from arthritic knees, "unloading" shoes don't offer a leg up ...

  4. Knee joint forces: prediction, measurement, and significance

    PubMed Central

    D’Lima, Darryl D.; Fregly, Benjamin J.; Patil, Shantanu; Steklov, Nikolai; Colwell, Clifford W.

    2011-01-01

    Knee forces are highly significant in osteoarthritis and in the survival and function of knee arthroplasty. A large number of studies have attempted to estimate forces around the knee during various activities. Several approaches have been used to relate knee kinematics and external forces to internal joint contact forces, the most popular being inverse dynamics, forward dynamics, and static body analyses. Knee forces have also been measured in vivo after knee arthroplasty, which serves as valuable validation of computational predictions. This review summarizes the results of published studies that measured knee forces for various activities. The efficacy of various methods to alter knee force distribution, such as gait modification, orthotics, walking aids, and custom treadmills are analyzed. Current gaps in our knowledge are identified and directions for future research in this area are outlined. PMID:22468461

  5. Deciding to have knee or hip replacement

    MedlinePlus

    ... patientinstructions/000368.htm Deciding to have knee or hip replacement To use the sharing features on this page, ... make a decision. Who Benefits From Knee or hip Replacement Surgery? The most common reason to have a ...

  6. Risks of hip and knee replacement

    MedlinePlus

    ... is normal to lose blood during and after hip or knee replacement surgery. Some people need a blood transfusion during ... clot form are higher during and soon after hip or knee replacement surgery. Sitting or lying down for long periods ...

  7. Knee joint forces: prediction, measurement, and significance.

    PubMed

    D'Lima, Darryl D; Fregly, Benjamin J; Patil, Shantanu; Steklov, Nikolai; Colwell, Clifford W

    2012-02-01

    Knee forces are highly significant in osteoarthritis and in the survival and function of knee arthroplasty. A large number of studies have attempted to estimate forces around the knee during various activities. Several approaches have been used to relate knee kinematics and external forces to internal joint contact forces, the most popular being inverse dynamics, forward dynamics, and static body analyses. Knee forces have also been measured in vivo after knee arthroplasty, which serves as valuable validation of computational predictions. This review summarizes the results of published studies that measured knee forces for various activities. The efficacy of various methods to alter knee force distribution, such as gait modification, orthotics, walking aids, and custom treadmills are analyzed. Current gaps in our knowledge are identified and directions for future research in this area are outlined. PMID:22468461

  8. The use of the greater trochanter marker in the thigh segment model: implications for hip and knee frontal and transverse plane motion

    PubMed Central

    Graci, Valentina; Salsich, Gretchen

    2015-01-01

    Background The greater trochanter marker is commonly used in 3-dimensional models; however, its influence on hip and knee kinematics during gait is unclear. Understanding the influence of the greater trochanter marker is important when quantifying frontal and transverse plane hip and knee kinematics, parameters which are particularly relevant to investigate in individuals with conditions such as patellofemoral pain, knee osteoarthritis, ACL injury and hip pain. The aim of this study was to evaluate the effect of including the greater trochanter in the construction of the thigh segment on hip and knee kinematics during gait. Methods Three-dimensional kinematics were collected in 19 healthy subjects during walking using a surface marker system. Hip and knee angles were compared across two thigh segment definitions (with and without greater trochanter) at two time points during stance: peak knee flexion (PKF) and minimum knee flexion (MinKF). Results Hip and knee angles differed in magnitude and direction in the transverse plane at both time points. In the thigh model with the greater trochanter the hip was more externally rotated than in the thigh model without the greater trochanter, (PKF −9.34°±5.21° vs 1.40°±5.22°, MinKF −5.68°±4.24° vs 5.01°±4.86°, p<0.001). In the thigh model with the greater trochanter, the knee angle was more internally rotated compared to the knee angle calculated using the thigh definition without the greater trochanter (PKF 14.67°±6.78° vs 4.33°±4.18°, MinKF 10.54°±6.71° vs −0.01°±2.69°, p<.001). Small but significant differences were detected in the sagittal and frontal plane angles at both time points (p<.001). Conclusion Hip and knee kinematics differed across different segment definitions including or excluding the greater trochanter marker, especially in the transverse plane. Therefore when considering whether to include the greater trochanter in the thigh segment model when using a surface markers to

  9. Predicting Knee Osteoarthritis.

    PubMed

    Gardiner, Bruce S; Woodhouse, Francis G; Besier, Thor F; Grodzinsky, Alan J; Lloyd, David G; Zhang, Lihai; Smith, David W

    2016-01-01

    Treatment options for osteoarthritis (OA) beyond pain relief or total knee replacement are very limited. Because of this, attention has shifted to identifying which factors increase the risk of OA in vulnerable populations in order to be able to give recommendations to delay disease onset or to slow disease progression. The gold standard is then to use principles of risk management, first to provide subject-specific estimates of risk and then to find ways of reducing that risk. Population studies of OA risk based on statistical associations do not provide such individually tailored information. Here we argue that mechanistic models of cartilage tissue maintenance and damage coupled to statistical models incorporating model uncertainty, united within the framework of structural reliability analysis, provide an avenue for bridging the disciplines of epidemiology, cell biology, genetics and biomechanics. Such models promise subject-specific OA risk assessment and personalized strategies for mitigating or even avoiding OA. We illustrate the proposed approach with a simple model of cartilage extracellular matrix synthesis and loss regulated by daily physical activity. PMID:26206679

  10. Early knee osteoarthritis

    PubMed Central

    Favero, Marta; Ramonda, Roberta; Goldring, Mary B; Goldring, Steven R; Punzi, Leonardo

    2015-01-01

    Concepts regarding osteoarthritis, the most common joint disease, have dramatically changed in the past decade thanks to the development of new imaging techniques and the widespread use of arthroscopy that permits direct visualisation of intra-articular tissues and structure. MRI and ultrasound allow the early detection of pre-radiographic structural changes not only in the peri-articular bone but also in the cartilage, menisci, synovial membrane, ligaments and fat pad. The significance of MRI findings such as cartilage defects, bone marrow lesions, synovial inflammation/effusions and meniscal tears in patients without radiographic signs of osteoarthritis is not fully understood. Nevertheless, early joint tissue changes are associated with symptoms and, in some cases, with progression of disease. In this short review, we discuss the emerging concept of early osteoarthritis localised to the knee based on recently updated knowledge. We highlight the need for a new definition of early osteoarthritis that will permit the identification of patients at high risk of osteoarthritis progression and to initiate early treatment interventions. PMID:26557380

  11. TOTAL KNEE REPLACEMENT IN PATIENTS WITH BELOW-KNEE AMPUTATION

    PubMed Central

    Karam, Matthew D; Willey, Michael; Shurr, Donald G

    2010-01-01

    Total knee replacement (TKR) is reserved for patients with severe and disabling arthritis that is non-responsive to conservative measures. Based on existing data, total knee replacement is a safe and cost-effective treatment for alleviating pain and improving physical function in patients who do not respond to conservative therapy. Despite the large variation in health status of patients and types of prosthesis implanted, total knee replacement has proven to be a relatively low risk and successful operation. Each year in the United States surgeons perform approximately 300,000 TKR.1 Likewise, lower extremity amputation is commonly performed in the United States with an annual incidence of 110,000 per year.2 Nearly 70% of all lower extremity amputations are performed as the result of chronic vascular disease, followed by trauma (22%), congenital etiology and tumor (4% each).3 Approximately 50% of all lower extremity amputations are performed secondary to complications from Diabetes Mellitus. Norvell et al. demonstrated that patients who have previously undergone transtibial amputation and ambulate with a prosthesis are more likely to develop degenerative joint disease in the con-tralateral extremity than the ipsilateral extremity.4 Further, radiographic changes consistent with osteoporosis have been demonstrated in up to 88% of limbs that have undergone transtibial amputation.8 To our knowledge, there have been only three reported cases of total knee replacement in patients with ipsilateral transtibial amputation.5,7 The purpose of the present study is to review the existing data on total knee replacement in patients who have undergone transtibial amputation. Further we present a patient with a transtibial amputation who underwent contralateral total knee replacement. PMID:21045987

  12. Long-Term Data Reveal Rate and Risk Factors for Subsequent Surgeries Following Initial ACL Reconstruction

    MedlinePlus

    ... we have not known the rate and risk factors for subsequent knee surgery until now,” said senior author Kurt Spindler, M.D., of Vanderbilt University. In the Multicenter Orthopaedic Outcomes Network (MOON) study, ...

  13. Self-reported previous knee injury and low knee function increase knee injury risk in adolescent female football.

    PubMed

    Clausen, M B; Tang, L; Zebis, M K; Krustrup, P; Hölmich, P; Wedderkopp, N; Andersen, L L; Christensen, K B; Møller, M; Thorborg, K

    2016-08-01

    Knee injuries are common in adolescent female football. Self-reported previous knee injury and low Knee injury and Osteoarthritis Outcome Score (KOOS) are proposed to predict future knee injuries, but evidence regarding this in adolescent female football is scarce. The aim of this study was to investigate self-reported previous knee injury and low KOOS subscale score as risk factors for future knee injuries in adolescent female football. A sample of 326 adolescent female football players, aged 15-18, without knee injury at baseline, were included. Data on self-reported previous knee injury and KOOS questionnaires were collected at baseline. Time-loss knee injuries and football exposures were reported weekly by answers to standardized text-message questions, followed by injury telephone interviews. A priori, self-reported previous knee injury and low KOOS subscale scores (< 80 points) were chosen as independent variables in the risk factor analyses. The study showed that self-reported previous knee injury significantly increased the risk of time-loss knee injury [relative risk (RR): 3.65, 95% confidence (CI) 1.73-7.68; P < 0.001]. Risk of time-loss knee injury was also significantly increased in players with low KOOS subscale scores (< 80 points) in Activities of Daily Living (RR: 5.0), Sport/Recreational (RR: 2.2) and Quality of Life (RR: 3.0) (P < 0.05). In conclusion, self-reported previous knee injury and low scores in three KOOS subscales significantly increase the risk of future time-loss knee injury in adolescent female football. PMID:26179111

  14. Knee Joint Laxity and Its Cyclic Variation Influence Tibiofemoral Motion during Weight Acceptance

    PubMed Central

    Shultz, Sandra J.; Schmitz, Randy J.; Nguyen, Anh-Dung; Levine, Beverly; Kim, Hyunsoo; Montgomery, Melissa M.; Shimokochi, Yohei; Beynnon, Bruce D.; Perrin, David H.

    2010-01-01

    Purpose To better understand how sex differences in anterior knee joint laxity (AKL) impact knee joint biomechanics, we examined the consequence of greater absolute baseline (males and females) and cyclic increases in AKL during the menstrual cycle (females) on anterior tibial translation (ATT) as the knee transitioned from non-weight bearing (NWB) to weight bearing (WB) conditions, while also controlling for genu recurvatum (GR). Methods Males and females (71F,48M;18-30 years) were measured for AKL and GR, and underwent measurement of ATT. Females were tested on the days of their cycle when AKL was at its minimum (T1) and maximum (T2); males were matched in time to a female with similar AKL. Linear regressions examined relationships between absolute baseline (AKLT1, GRT1) and cyclic changes (Δ=T2-T1; AKLΔ, GRΔ)(females only) in knee laxity with ATT as measured at T1 and T2, and Δ (T2-T1) (females only). Results AKL and GR increased in females, but not males, from T1 to T2. Greater AKLT1 and GRT1 predicted greater ATTT1 and ATTT2 in males (R2=21.0, P<.007). The combination of greater AKLT1, AKLΔ and less GRΔ predicted greater ATTT1 and ATTT2 in females (R2=12.5-13.1, P<.05), with AKLΔ being a stronger predictor (coefficient, P-value) of ATTT2 (0.864, P=.027) compared to ATTT1 (0.333, P=.370). AKLΔ was the sole predictor of ATTΔ (R2=.104; 0.740, P=.042). Conclusions Greater absolute baseline and cyclic increases in AKL were consistently associated with greater ATT produced by transition of the knee from NWB to WB. As the ACL is the primary restraint to ATT, these findings provide insight into possible mechanisms by which greater AKL may be associated with at risk knee biomechanics during the weight acceptance phase of dynamic tasks. PMID:20581718

  15. Snapping knee caused by symptomatic fabella in a native knee.

    PubMed

    Hire, Justin M; Oliver, David L; Hubbard, Ryan C; Fontaine, Michelle L; Bojescul, John A

    2014-08-01

    We report a case of a 31-year-old man with a 5-year history of snapping knee syndrome secondary to a single, large symptomatic fabella of the knee. On physical examination, the patient was able to reproduce an audible and palpable snapping with active range of motion. His condition was refractory to physical therapy. He had undergone a prior iliotibial band release at an outside facility. After excision of the fabella, measuring 15 × 8 × 9 mm, the patient's snapping and pain with activity were resolved. PMID:25136872

  16. Automatically Locking/Unlocking Orthotic Knee Joint

    NASA Technical Reports Server (NTRS)

    Weddendorf, Bruce

    1994-01-01

    Proposed orthotic knee joint locks and unlocks automatically, at any position within range of bend angles, without manual intervention by wearer. Includes tang and clevis, locks whenever wearer transfers weight to knee and unlocks when weight removed. Locking occurs at any angle between 45 degrees knee bend and full extension.

  17. Knee Replacement - Multiple Languages: MedlinePlus

    MedlinePlus

    ... Knee Replacement (Arabic) العربية Bilingual PDF Health Information Translations Bosnian (Bosanski) Total Knee Replacement Potpuna zamjena koljena - Bosanski (Bosnian) Bilingual PDF Health Information Translations Chinese - Simplified (简体中文) Total Knee Replacement 全膝关节置换 - 简体中文 ( ...

  18. Assessment of the Impacts of ACLS on the ISS Life Support System Using Dynamic Simulations in V-HAB

    NASA Technical Reports Server (NTRS)

    Putz, Daniel; Olthoff, Claas; Ewert, Michael; Anderson, Molly

    2016-01-01

    The Advanced Closed Loop System (ACLS) is currently under development by Airbus Defense and Space and is slated for launch to the International Space Station (ISS) in 2017. The addition of new hardware into an already complex system such as the ISS life support system (LSS) always poses operational risks. It is therefore important to understand the impacts ACLS will have on the existing systems to ensure smooth operations for the ISS. This analysis can be done by using dynamic computer simulations and one possible tool for such a simulation is the Virtual Habitat (V-HAB). Based on MATLAB, V-HAB has been under development at the Institute of Astronautics of the Technical University of Munich (TUM) since 2004 and in the past has been successfully used to simulate the ISS life support systems. The existing V-HAB ISS simulation model treated the interior volume of the space station as one large, ideally-stirred container. This model was improved to allow the calculation of the atmospheric composition inside individual modules of the ISS by splitting it into twelve distinct volumes. The virtual volumes are connected by a simulation of the inter-module ventilation flows. This allows for a combined simulation of the LSS hardware and the atmospheric composition aboard the ISS. A dynamic model of ACLS is added to the ISS Simulation and several different operating modes for both ACLS and the existing ISS life support systems are studied and the impacts of ACLS on the rest of the system are determined. The results suggest that the US, Russian and ACLS CO2 systems can operate at the same time without impeding each other. Furthermore, based on the results of this analysis, the US and ACLS Sabatier systems can be operated in parallel as well to a achieve a very low CO2 concentration in the cabin atmosphere.

  19. Assessment of the Impacts of ACLS on the ISS Life Support System using Dynamic Simulations in V-HAB

    NASA Technical Reports Server (NTRS)

    Puetz, Daniel; Olthoff, Claas; Ewert, Michael K.; Anderson, Molly S.

    2016-01-01

    The Advanced Closed Loop System (ACLS) is currently under development by Airbus Defense and Space and is slated for launch to the International Space Station (ISS) in 2017. The addition of new hardware into an already complex system such as the ISS life support system (LSS) always poses operational risks. It is therefore important to understand the impacts ACLS will have on the existing systems to ensure smooth operations for the ISS. This analysis can be done by using dynamic computer simulations and one possible tool for such a simulation is Virtual Habitat (V-HAB). Based on Matlab (Registered Trademark) V-HAB has been under development at the Institute of Astronautics of the Technical University Munich (TUM) since 2006 and in the past has been successfully used to simulate the ISS life support systems. The existing V-HAB ISS simulation model treated the interior volume of the space station as one large ideally-stirred container. This model was improved to allow the calculation of the atmospheric composition inside the individual modules of the ISS by splitting it into ten distinct volumes. The virtual volumes are connected by a simulation of the inter-module ventilation flows. This allows for a combined simulation of the LSS hardware and the atmospheric composition aboard the ISS. A dynamic model of ACLS is added to the ISS simulation and different operating modes for both ACLS and the existing ISS life support systems are studied to determine the impacts of ACLS on the rest of the system. The results suggest that the US, Russian and ACLS CO2 systems can operate at the same time without impeding each other. Furthermore, based on the results of this analysis, the US and ACLS Sabatier systems can be operated in parallel as well to achieve the highest possible CO2 recycling together with a low CO2 concentration.

  20. [Imaging strategies for knee injuries].

    PubMed

    Hegenscheid, K; Puls, R; Rosenberg, C

    2012-11-01

    Injuries of the knees are common. The Ottawa knee rule provides decisional support to determine whether radiographs are indicated or not. With the use of ultrasound it is possible to detect defects of the extensor ligaments and the anterior cruciate ligament. Furthermore, it is possible to detect indirect signs of an intra-articular fracture, e.g. lipohemarthrosis. In complex fractures, e.g. tibial plateau fractures, further diagnostic procedures with multislice computed tomography (CT) are needed for accurate classification and preoperative planning. Multislice CT with CT angiography enables three-dimensional reconstruction of the knee and non-invasive vascular imaging for detection of vascular injury. Magnetic resonance imaging (MRI) is the gold standard for detection of occult fractures and injuries of the ligaments and menisci. Higher field strengths can be used to improve the diagnostics of cartilage lesions. Virtual MR arthrography is superior to conventional MRI for detection of cartilage lesions especially after meniscus surgery. PMID:23154845

  1. Robotic-assisted knee arthroplasty.

    PubMed

    Banerjee, Samik; Cherian, Jeffrey J; Elmallah, Randa K; Jauregui, Julio J; Pierce, Todd P; Mont, Michael A

    2015-01-01

    Robotics in total knee arthroplasty (TKA) has undergone vast improvements. Although some of the systems have fallen out of favor due to safety concerns, there has been recent increased interest for semi-active haptic robotic systems that provide intraoperative tactile feedback to the surgeon. The potential advantages include improvements in radiographic outcomes, reducing the incidence of mechanical axis malalignment of the lower extremity and better tissue balance. Proponents of robotic technology believe that these improvements may lead to superior functional outcomes and implant survivorship. We aim to discuss robotic technology development, outcomes of unicompartmental and total knee arthroplasty and the future outlook. Short-term follow-up studies on robotic-assisted knee arthroplasty suggest that, although some alignment objectives may have been achieved, more studies regarding functional outcomes are needed. Furthermore, studies evaluating the projected cost-benefit analyses of this new technology are needed before widespread adoption. Nevertheless, the short-term results warrant further evaluation. PMID:26365088

  2. Early osteoarthritis of the knee.

    PubMed

    Madry, Henning; Kon, Elizaveta; Condello, Vincenzo; Peretti, Giuseppe M; Steinwachs, Matthias; Seil, Romain; Berruto, Massimo; Engebretsen, Lars; Filardo, Giuseppe; Angele, Peter

    2016-06-01

    There is an increasing awareness on the importance in identifying early phases of the degenerative processes in knee osteoarthritis (OA), the crucial period of the disease when there might still be the possibility to initiate treatments preventing its progression. Early OA may show a diffuse and ill-defined involvement, but also originate in the cartilage surrounding a focal lesion, thus necessitating a separate assessment of these two entities. Early OA can be considered to include a maximal involvement of 50 % of the cartilage thickness based on the macroscopic ICRS classification, reflecting an OARSI grade 4. The purpose of this paper was to provide an updated review of the current status of the diagnosis and definition of early knee OA, including the clinical, radiographical, histological, MRI, and arthroscopic definitions and biomarkers. Based on current evidence, practical classification criteria are presented. As new insights and technologies become available, they will further evolve to better define and treat early knee OA. PMID:27000393

  3. Controversies in Knee Rehabilitation: Anterior Cruciate Ligament Injury

    PubMed Central

    Failla, Mathew J.; Arundale, Amelia J.H.; Logerstedt, David S.; Snyder-Mackler, Lynn

    2014-01-01

    Controversy in management of athletes exists after anterior cruciate ligament injury and reconstruction. Consensus criteria for evaluating successful outcomes following ACL injury include no re-injury or recurrent giving way, no joint effusion, quadriceps strength symmetry, restored activity level and function, and returning to pre-injury sports. Using these criterions, we will review the success rates of current management strategies after ACL injury and provide recommendations for the counseling of athletes after ACL injury. PMID:25818715

  4. Arthroscopic surgery of the knee.

    PubMed Central

    Dandy, D J; O'Carroll, P F

    1982-01-01

    In the first 1000 arthroscopic operations performed by one surgeon 136 patients had two or more procedures, making a total of 1168 during the 1000 operations. The indications for operation were internal mechanical derangements in 565 patients, anterior knee pain in 246, disorders of the synovium in 77, ligament injuries in 63, and degenerative joint disease in 49. Complications included fracture of instruments in the knee in five patients, haemarthrosis in 10, deep vein thrombosis in three, and synovial fistula in one. In no patient was the wound infected. A total of 26 different operations was performed. PMID:6812832

  5. [Revision after unicompartmental knee arthroplasty].

    PubMed

    Mohr, G; Martin, J; Clarius, M

    2014-10-01

    Unicompartmental arthroplasty is an efficient and approved treatment option of unicompartmental arthritis of the knee, being performed with increasing frequency worldwide. Compared to total knee replacement, there are several advantages such as faster recovery, lower blood loss, better functional outcome and lower infection rates. However, higher revision rates are a frequent argument against the use of unicompartmental arthroplasty. The following article gives an overview of failure mechanisms and strategies for revision arthroplasty. This article is based on a selective literature review including PubMed and relevant print media. Our own clinical experience is considered as well. PMID:25209015

  6. Identification and functional characterization of AclB, a novel cell-separating enzyme from Lactobacillus casei.

    PubMed

    Xu, Yi; Wang, Ting; Kong, Jian; Wang, Hui-Li

    2015-06-16

    Autolysis of nonstarter lactic acid bacteria (NSLAB) was favorable for the development of flavor compounds during cheese manufacture. Among these bacteria, Lb. casei was regarded as the most important microbiota involved in cheese processes. In this study, a novel autolysin named AclB was identified in the genome of Lb. casei BL23 and its modular structure was predicted through bioinformatic approaches. Subsequently, its transcription profile in the exponential phase, hydrolytic activities against cell walls, enzymatic properties under different conditions, physiological function via gene inactivation and upregulation assays, as well as potential applications to NSLAB's autolysis were fully investigated. According to the results, AclB was recognized as a species-specific cell-separating enzyme, responsible for cell separation after cell division in Lb. casei BL23. The purified AclB showed considerable hydrolyzing activities towards cell walls, indicating its enzymatic nature as peptidoglycan hydrolase, or autolysin. The highest activity of AclB was determined at pH5.0 and 37°C, and the expression vector constructed based on AclB was shown to facilitate the controlled lysis of Lb. casei BL23 hosts. In summary, this study provided insight into the enzymatic properties of a novel autolysin involved in cell separation of Lb. casei BL23, which is promising to accelerate cheese ripening and improve cheese quality. PMID:25797034

  7. Low Vitamin D levels are associated with greater pain and slow walking speed in patients with knee osteoarthritis (KOA)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The clinical status of patients with knee OA is primarily predicated by their level of pain and their muscle function. Recent studies have shown that vitamin D influences both musculoskeletal health and neuromuscular function. Vitamin D deficiency is common among elders and those with comorbidities....

  8. Sex, Age, and Graft Size as Predictors of ACL Re-tear

    PubMed Central

    Nguyen, Duong

    2016-01-01

    Objectives: The minimum size required for a successful quadrupled hamstring autograft ACL reconstruction remains controversial. The risks of ACL re-tear in younger patients who tend to participate in a higher level of sports activity, and female athletes who have numerous predisposing factors, are poorly defined. Purpose: To identify risk factors for graft re-tears within 2 years of ACL surgery. The hypotheses are that female sex, a smaller size graft, and younger patients will increase the odds of failure. Study Design Cohort Study. Level of evidence, 3. Methods: A cohort of 503 athletes undergoing primary, autograft hamstring ACL reconstruction, performed by a single surgeon using the same surgical technique and rehabilitation protocol, between September-December 2012, was followed for a total duration of 2 years. Return to play was allowed between 6 and 12 months post-surgery upon completion of functional testing. Exclusion criteria included infections, revisions, double bundle techniques, multi-ligament injuries, non-compliance, BTB/allografts/hybrid grafts. Primary outcome consisted of binary data (ACL graft re-tear or no tear) as measured on physical exam (Lachman and pivot shift) and MRI. Multivariate logistic regression statistical analysis with model fitting was used to investigate the predictive value of sex, age, and graft size on ACL re-tear. Secondary sensitivity analyses were performed on the adolescent subgroup, age and graft size as categorical variables, and testing for interactions among variables. Sample size was calculated based on the rule of 10 events per independent variable for logistic regression. Results: The mean age of the 503 athletes was 27.5 (SD 10.6; range = 12-61). There were 235 females (47%) and 268 males (53%) with a 6% rate of re-tears (28 patients; 17 females). Mean graft size was 7.9 (SD 0.6; range = 6-10). Univariate analyses of graft size, sex, and age only in the model showed that younger age (odds ratio [OR] = 0.86; 95

  9. Trabecular bone strength at the knee.

    PubMed

    Hvid, I

    1988-02-01

    The axial strength of trabecular bone at the knee is critical for the maintenance of support and fixation of the prosthetic components after total surface knee arthroplasty. The resistance of trabecular bone to penetration was measured posteriorly, centrally, and anteriorly in each of the tibial and femoral condyles in 150 consecutive total knee arthroplasties. Forty-seven rheumatoid knees and 88 osteoarthritic knees were evaluated. The correlation of bone strength with selected clinical parameters was found to be too poor to predict bone strength. Tibial bone strength was lower in rheumatoid than in osteoarthritic knees. Steroid medication did not influence tibial bone strength in rheumatoid arthritis. The distribution of bone strength between the medial and lateral condyles was closely dependent on knee alignment, with high medial strength in varus knees. At the unloaded condyle, strength was reduced relative to the findings for normally aligned knees. At the tibia, strength decreased with depth from the resection surface, while at the femur the converse was true. Tibial bone strength, both condylar and overall average, was lower than values reported in studies of normal cadaver knees. Evaluation of the absolute bone strength at the tibial condyles suggested that the values too low to meet load-bearing requirements after well-aligned knee replacement were infrequent. PMID:3276421

  10. Deprivation and outcome of total knee replacement.

    PubMed

    Murray, James R D; Birdsall, Paul D; Sher, J Lester; Deehan, David J

    2006-03-01

    Deprivation correlates with poor health and psychosocial variables can affect the symptoms of knee arthritis. Our aim was to determine the effect of deprivation on the level of knee function and health-related quality of life at the time of arthroplasty and 12 months after total knee replacement. From our database of over 2500 knee replacements, we analysed both clinical and quality of life outcome measures. We analysed the relationship between deprivation (by Townsend score), knee function (Knee Society Score) and health-related quality of life (Nottingham Health Profile) before total knee replacement (TKR) and at 12 months post-operation. There was no significant correlation between Townsend score, Knee Society Score and Nottingham Health Profile preoperatively or at 12 months after knee replacement, thus showing that there was no association between deprivation and the severity of knee arthritis at the time of joint replacement nor was there a relationship between deprivation and the short-term outcome from total knee replacement. PMID:16469499

  11. Biomechanics of knee joint — A review

    NASA Astrophysics Data System (ADS)

    Madeti, Bhaskar Kumar; Chalamalasetti, Srinivasa Rao; Bolla Pragada, S. K. Sundara siva rao

    2015-06-01

    The present paper is to know how the work is carried out in the field of biomechanics of knee. Various model formulations are discussed and further classified into mathematical model, two-dimensional model and three-dimensional model. Knee geometry is a crucial part of human body movement, in which how various views of knee is shown in different planes and how the forces act on tibia and femur are studied. It leads to know the forces acting on the knee joint. Experimental studies of knee geometry and forces acting on knee shown by various researchers have been discussed, and comparisons of results are made. In addition, static and dynamic analysis of knee has been also discussed respectively to some extent.

  12. Tensions in the anterior and posterior cruciate ligaments of the knee during passive loading: predicting ligament loads from in situ measurements.

    PubMed

    Vahey, J W; Draganich, L F

    1991-07-01

    Cruciate ligament tensions were predicted for anteroposterior (AP) tibial translation at 20 degrees, 30 degrees, 80 degrees, and 90 degrees of knee flexion based on in vitro measurements from six cadaver knees. A three-dimensional trigonometric equation was derived to calculate cruciate ligament tension as functions of AP force applied to the tibia and knee flexion angle (KFA). AP forces less than or equal to 150 N were applied. Ligament tension increased with applied AP force. The relationship between ligament tension and applied AP force appeared linear, but a Hotteling's T2 test failed to demonstrate a linear relationship. Tensions in the anterior cruciate ligament (ACL) attained magnitudes of approximately equal to 140 N. Tensions in the posterior cruciate ligament (PCL) attained magnitudes of approximately equal to 220 N. An analysis was performed to determine the sensitivity of ligament tension to hypothetical errors in the experimentally measured parameters used to compute ligament tension. The new method we report can be used to determine tensions in the ligaments of the knee or other joints for various loading conditions. PMID:2045979

  13. Open Knee: Open Source Modeling and Simulation in Knee Biomechanics.

    PubMed

    Erdemir, Ahmet

    2016-02-01

    Virtual representations of the knee joint can provide clinicians, scientists, and engineers the tools to explore mechanical functions of the knee and its tissue structures in health and disease. Modeling and simulation approaches such as finite element analysis also provide the possibility to understand the influence of surgical procedures and implants on joint stresses and tissue deformations. A large number of knee joint models are described in the biomechanics literature. However, freely accessible, customizable, and easy-to-use models are scarce. Availability of such models can accelerate clinical translation of simulations, where labor-intensive reproduction of model development steps can be avoided. Interested parties can immediately utilize readily available models for scientific discovery and clinical care. Motivated by this gap, this study aims to describe an open source and freely available finite element representation of the tibiofemoral joint, namely Open Knee, which includes the detailed anatomical representation of the joint's major tissue structures and their nonlinear mechanical properties and interactions. Three use cases illustrate customization potential of the model, its predictive capacity, and its scientific and clinical utility: prediction of joint movements during passive flexion, examining the role of meniscectomy on contact mechanics and joint movements, and understanding anterior cruciate ligament mechanics. A summary of scientific and clinically directed studies conducted by other investigators are also provided. The utilization of this open source model by groups other than its developers emphasizes the premise of model sharing as an accelerator of simulation-based medicine. Finally, the imminent need to develop next-generation knee models is noted. These are anticipated to incorporate individualized anatomy and tissue properties supported by specimen-specific joint mechanics data for evaluation, all acquired in vitro from varying age

  14. Sociodemographic and environmental risk factors for American cutaneous leishmaniasis (ACL) in the State of Alagoas, Brazil.

    PubMed

    Pedrosa, Fernando de Araújo; Ximenes, Ricardo Arraes de Alencar

    2009-08-01

    The multiplicity of factors involved in the transmission of the American cutaneous leishmaniasis (ACL) constitutes a challenge to its control. Thus, knowledge of such factors may contribute extremely toward redefining the control strategies. The aim of this study was to identify sociodemographic and environmental factors relating to ACL transmission in the State of Alagoas, Brazil. A case-control study with incident cases was conducted. Diagnostic criteria were the presence of compatible skin lesions, laboratory confirmation, and clinical cure after treatment. Two control groups were matched to cases by sex and age: one comprising neighbors and the other from a community-based draw; controls were individuals with no lesion and a negative Montenegro intradermal reaction. Between July 1, 2004 and February 1, 2007, 98 cases and the same number of controls per group were selected. In the multivariate analysis, for both control groups, ACL was associated with absence of a gas stove and forest less than 200 m away; for neighborhood controls with schooling of 4 years or less, family income greater than one minimum salary, birds inside the home, forest-related leisure activities, and rural work or school activities; and for community controls with non-durable wall material in the house, per capita income greater than US$ 28.31, animals inside the house, and absence of dogs and cats around the house. Specific control measures are recommended for areas with similar characteristics: protection for individuals undertaking forest-related leisure activities; distancing houses from forests by more than 200 m; and elimination of bird or other animal-rearing inside homes. General measures of improved housing and living conditions are also recommended. PMID:19635869

  15. Prevention of Cartilage Degeneration and Gait Asymmetry by Lubricin Tribosupplementation in the Rat Following ACL Transection

    PubMed Central

    Jay, Gregory D.; Elsaid, Khaled A.; Kelly, Karen A.; Anderson, Scott C.; Zhang, Ling; Teeple, Erin; Waller, Kimberly; Fleming, Braden C.

    2011-01-01

    Objective To investigate whether cartilage degeneration is prevented or minimized in an anterior cruciate ligament (ACL) injury rat model following a single dose-escalated intra-articular injection of lubricin derived from human synoviocytes in culture (HSL). Methods Unilateral ACL transection (ACLT) of the right hindlimb was performed in Lewis rats (N = 56). Control animals underwent a capsulotomy alone leaving the ACL intact (N = 11). Intra-articular injections (50μl/injection) of PBS (N = 14) and HSL (N = 14; 1600μg/ml) were performed on day 7 post-surgery. Animals were euthanized on day 70 post-surgery. Histological specimens were immunoprobed for lubricin, and sulfated glycosaminoglycans. Urinary CTX-II (uCTX-II) levels were measured on day 35 and 70 post-surgery. Hindlimb maximum applied force was determined using a variable resistor walkway to monitor quadruped gait asymmetries. Results Increased immunostaining for lubricin in the superficial zone and on the surface of cartilage was observed in lubricin-treated and control animals but not the PBS-treated nor the untreated ACLT animals. On post-operative day 35 and 70, uCTXII levels of HSL-treated animals were lower than corresponding untreated and PBS-treated (p=0.005; p<0.001 respectively) animals. ACLT animals treated with HSL and control animals distributed their weight equally between hindlimbs compared to PBS treated or untreated animals (p<0.01). Conclusion A single intra-articular injection of concentrated lubricin, following ACLT, reduced collagen type II degradation and improved weight bearing in the affected joint. This study supports the practice of tribosupplementation with lubricin in retarding cartilage degeneration and possibly the development of post-traumatic OA. PMID:22127873

  16. Hypoxic culture conditions induce increased metabolic rate and collagen gene expression in ACL-derived cells.

    PubMed

    Kowalski, Tomasz J; Leong, Natalie L; Dar, Ayelet; Wu, Ling; Kabir, Nima; Khan, Adam Z; Eliasberg, Claire D; Pedron, Andrew; Karayan, Ashant; Lee, Siyoung; Di Pauli von Treuheim, Theodor; Jiacheng, Jin; Wu, Ben M; Evseenko, Denis; McAllister, David R; Petrigliano, Frank A

    2016-06-01

    There has been substantial effort directed toward the application of bone marrow and adipose-derived mesenchymal stromal cells (MSCs) in the regeneration of musculoskeletal tissue. Recently, resident tissue-specific stem cells have been described in a variety of mesenchymal structures including ligament, tendon, muscle, cartilage, and bone. In the current study, we systematically characterize three novel anterior cruciate ligament (ACL)-derived cell populations with the potential for ligament regeneration: ligament-forming fibroblasts (LFF: CD146(neg) , CD34(neg) CD44(pos) , CD31(neg) , CD45(neg) ), ligament perivascular cells (LPC: CD146(pos) CD34(neg) CD44(pos) , CD31(neg) , CD45(neg) ) and ligament interstitial cells (LIC: CD34(pos) CD146(neg) , CD44(pos) , CD31(neg) , CD45(neg) )-and describe their proliferative and differentiation potential, collagen gene expression and metabolism in both normoxic and hypoxic environments, and their trophic potential in vitro. All three groups of cells (LIC, LPC, and LFF) isolated from adult human ACL exhibited progenitor cell characteristics with regard to proliferation and differentiation potential in vitro. Culture in low oxygen tension enhanced the collagen I and III gene expression in LICs (by 2.8- and 3.3-fold, respectively) and LFFs (by 3- and 3.5-fold, respectively) and increased oxygen consumption rate and extracellular acidification rate in LICs (by 4- and 3.5-fold, respectively), LFFs (by 5.5- and 3-fold, respectively), LPCs (by 10- and 4.5-fold, respectively) as compared to normal oxygen concentration. In summary, this study demonstrates for the first time the presence of three novel progenitor cell populations in the adult ACL that demonstrate robust proliferative and matrix synthetic capacity; these cells may play a role in local ligament regeneration, and consequently represent a potential cell source for ligament engineering applications. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc

  17. Vitamin D, Race, and Experimental Pain Sensitivity in Older Adults with Knee Osteoarthritis

    PubMed Central

    Glover, T.L.; Goodin, B.R.; Horgas, A.L.; Kindler, L.L.; King, C.D.; Sibille, K.T.; Peloquin, C.A.; Riley, J.L.; Staud, R.; Bradley, L.A.; Fillingim, R.B.

    2012-01-01

    Objective Low levels of serum circulating 25-hydroxyvitamin D have been correlated with many health conditions, including chronic pain. Recent clinical practice guidelines define vitamin D levels < 20 ng/mL as deficient and values of 21–29 ng/mL as insufficient. Vitamin D insufficiency, including the most severe levels of deficiency, is more prevalent in black Americans. Ethnic and race group differences have been reported in both clinical and experimental pain, with black Americans reporting increased pain. The purpose of this study was to examine whether variation in vitamin D levels contribute to race differences in knee osteoarthritic pain. Methods The sample consisted of 94 participants (75% female), including 45 blacks and 49 whites with symptomatic knee osteoarthritis. Average age was 55.8 years (range 45–71 years). Participants completed a questionnaire on knee osteoarthritic symptoms and underwent quantitative sensory testing, including measures of heat and mechanical pain sensitivity. Results Blacks had significantly lower levels of vitamin D compared to whites, demonstrated greater clinical pain, and showed greater sensitivity to mechanical and heat pain. Low levels of vitamin D predicted increased experimental pain sensitivity, but did not predict self-reported clinical pain. Group differences in vitamin D significantly predicted group differences in heat pain and pressure pain thresholds on the index knee and ipsilateral forearm. Conclusion These data demonstrate race differences in experimental pain are mediated by differences in vitamin D level. Vitamin D deficiency may be a risk factor for increased knee osteoarthritic pain in black Americans. PMID:23135697

  18. The Effect of a Novel Movement Strategy in Decreasing ACL Risk Factors in Female Adolescent Soccer Players: A Randomized Controlled Trial

    PubMed Central

    Celebrini, Richard G.; Eng, Janice J.; Miller, William C.; Ekegren, Christina L.; Johnston, James D.; Depew, Thomas A.; MacIntyre, Donna L.

    2015-01-01

    Objective To determine the effect of a novel movement strategy incorporated within a soccer warm-up on biomechanical risk factors for ACL injury during three sport-specific movement tasks. Design Single-blind, randomized controlled clinical trial. Setting Laboratory setting. Participants 20 top-tier female teenage soccer players. Interventions Subjects were randomized to the Core Position and Control movement strategy (Core-PAC) warm-up or standard warm-up which took place prior to their regular soccer practice over a 6-week period. The Core-PAC focuses on getting the centre of mass closer to the plant foot or base of support. Main Outcome Measures Peak knee flexion angle and abduction moments during a side-hop (SH), side-cut (SC) and unanticipated side-cut (USC) task after the 6-weeks with (intervention group only) and without a reminder to use the Core-PAC strategy. Results The Core-PAC group increased peak flexion angles during the SH task (Mean difference = 6.2°, 95% CI: 1.9–10.5°, effect size = 1.01, P = 0.034) after the 6-week warm-up program without a reminder. In addition, the Core-PAC group demonstrated increased knee flexion angles for the side-cut (Mean difference = 8.5°, 95% CI: 4.8–12.2°, ES = 2.02, P = 0.001) and side-hop (Mean difference = 10.0°, 95% CI: 5.7–14.3°, ES = 1.66, P = 0.001) task after a reminder. No changes in abduction moments were found. Conclusions The results of this study suggest that the Core-PAC may be one method of modifying high-risk soccer-specific movements and can be implemented within a practical, team-based soccer warm-up. The results should be interpreted with caution due to the small sample size. PMID:24184850

  19. Gap Balanced Total Knee Arthroplasty

    MedlinePlus

    Gap Balanced Total Knee Arthroplasty – SIGMA® with AOX™ You must have Javascript enabled in your web browser. View Program Transcript Click Here to view the OR-Live, Inc. Privacy Policy and Legal Notice © 2010 OR-Live, Inc. All rights reserved.

  20. Petriellidium boydii infection of knee

    SciTech Connect

    Kemp, H.B.S.; Bedford, A.F.; Fincham, W.J.

    1982-12-01

    A case of Petriellidium boydii (synonym: Allescheria boydii) infection of the knee joint is described. It followed a penetrating soft tissue injury with a pitchfork. Such infections are rare in this country and bone involvement has not been recorded previously except in maduramycosis contracted in tropical areas.