Anterior Cruciate Ligament

Anterior cruciate ligament (ACL) deficient and reconstructed knees display altered biomechanics during gait. Identifying significant gait changes is important for understanding normal and ACL function and is typically performed by statistical approaches. This paper focuses on the development of an explainable machine learning (ML) empowered methodology to: (i) identify important gait kinematic, kinetic parameters and quantify their contribution in the diagnosis of ACL injury and (ii) investigate the differences in sagittal plane kinematics and kinetics of the gait cycle between ACL deficient, ACL reconstructed and healthy individuals. For this aim, an extensive experimental setup was designed in which three-dimensional ground reaction forces and sagittal plane kinematic as well as kinetic parameters were collected from 151 subjects. The effectiveness of the proposed methodology was evaluated using a comparative analysis with eight well-known classifiers. Support Vector Machines were...

To evaluate the results of our method of surgical treatment of traumatic knee dislocation with injury to the posterolateral corner by use of a standardized protocol. Twenty-five consecutive patients presented with a grossly dislocated or reduced knee. Five of these patients were not included in this series. The remaining 20 patients were treated by primary arthroscopic reconstruction. The anterior cruciate ligament (ACL) was reconstructed using gracilis tendon reinforced with artificial ligament (Ligament Augmentation and Reconstruction System [LARS] ligament); the posterior cruciate ligament (PCL) was reconstructed with semitendinosus tendon and reinforced with LARS ligament; and the posterolateral corner was treated using the gracilis and semitendinosus tendons from the uninjured knee. Twenty patients returned for subjective and objective evaluation at a minimum of 24 months after surgery. Early mobilization through continuous and active exercise was started on the fourth day postoperatively. At a mean follow-up of 44 months, the mean Lysholm score was 90 points, the mean score on the survey of daily activities was 90 points, and the sports activities score on the knee outcome survey averaged 80 points. By the rating of Meyers et al. the results were excellent in 6 patients, good in 10 patients, fair in 3 patients, and poor in one patient. The final International Knee Documentation Committee (IKDC) rating was not normal in any knee. The mean loss of extension was 2° (range, 0° to 3°) and loss of flexion was 12° (range, 10° to 15°). By using the described method of arthroscopically assisted reconstruction of the cruciate ligaments and the posterolateral corner, 80% of the patients had good subjective results and functional stability, and according to the IKDC scale, 45% of knees were nearly normal, 45% were abnormal, and 10% were severely abnormal. No patient's rating returned to normal. Level IV, therapeutic case series.

To biomechanically compare anterior cruciate ligament (ACL) tibial bony avulsion fixation by suture anchors, EndoButtons (Smith & Nephew, Andover, MA), and high-strength sutures subjected to cyclic loading. Methods: Type III tibial eminence fractures were created in 49 ovine knees, and 7 different types of repairs were performed. Each repair group contained 7 specimens. The repair groups were as follows: No.

In this pilot study fusion motion capture (FMC) has been used to capture 3-D kinetics and kinematics of alpine ski racing. The new technology has overcome the technological difficulties associated with athlete performance monitoring in an alpine environment. FMC is a general term to describe motion capture when several different streams of data are fused to measure athlete motion. In this article inertial measurement units (IMU), global positioning system (GPS) pressure sensitive insoles, video and theodolite measurements have been combined. The core of the FMC is the fusion of IMU and GPS data. IMU may contain accelerometers, gyroscopes, magnetometers and a thermometer, and they track local orientation and acceleration of each limb segment of interest. GPS data are fused with local acceleration data to track the global trajectory of the athlete. Fusion integration algorithms designed by the authors [1] were used to improve the accuracy of the independent Kalman filter solutions provided by the vendors of both the GPS and IMU. The GPS accuracy was improved from a dilution of precision of 75 m (meaning 50% of the measurements will be within 5 m of the true value) to a maximum error of 71.5 m over the race course, while the IMU orientation error was reduced from over 201 to less than 51. The reader is invited to assess the validity of these results by comparing videos of the motion to the fusion motion capture output in the electronic version of this manuscript. Accuracy in laboratory situations has been validated, [2,3] but because such systems are becoming more popular, this system needs to be validated on the snow. As more accurate dual frequency GPS systems become less expensive this type of system will become more accurate and affordable. A biomechanical analysis was undertaken of a New Zealand Alpine Ski Racing Team member negotiating a 10-gate giant slalom course over 300 m in length. The abundant data in the results were used to create new tools for measuring alpine ski racing technique, such as colour-coded force vector analysis. The new parameters introduced in this article, such as effective inclination and ground reaction force power, are independent of the stylistic constraints often imposed by the coach or athlete. Two ski runs have been compared. Although the difference between the two run times was only 0.14 s or 1%, FMC and force vector analysis were able to

The use of naturally occurring extracellular matrix materials as scaffolds for the repair and regeneration of tissues is receiving increased attention. The present study evaluates the use of the extracellular matrix derived from porcine small intestinal submucosa as a scaffold for anterior cruciate ligament replacement in a goat model. Sixty healthy adult female goats were divided into two equal groups of 30 each. The right anterior cruciate ligament of each goat was removed surgically and replaced with either a patellar tendon autograft or a small intestinal submucosa anterior cruciate ligament scaffold. Three animals from each group were sacrificed at 6 weeks, 3 months, 6 months, and 1 year after surgery and grafts were harvested for histopathologic examination. Six animals from each group were sacrificed immediately after surgery, 3 months, and 1 year after surgery and the grafts were harvested for bio-mechanical testing. There was no evidence for an adverse clinical response to the xenogeneic small intestinal submucosa scaffold. Anterior drawer values were not different between the two groups at any point. The failure force of the patellar tendon autograft increased from 253 N at Time 0 to 879 N at 12 months. The failure force for the small intestinal submucosa repair device was 721 N at Time 0, decreased to 293 N at 3 months, followed by an increase to 706 N at 12 months. Histopathologic analysis showed a mixed inflammatory cell presence within the small intestinal submucosa scaffold including macrophages and lymphocytes in the early months after surgery. The inflammatory cells disappeared in the later stages of remodeling and the histologic appearance of the small intestinal submucosa remodeled grafts and the patellar tendon autografts were indistinguishable at 12 months. Xenogeneic small intestinal submucosa holds promise as a resorbable bioscaffold for anterior cruciate ligament repair in the goat model.

Activation of nuclear factor kappa B (NF-jB) in synovial cells is seen in RA and OA patients. Caffeic acid phenethyl ester (CAPE) is a specific and potent inhibitor of NF-jB. We aimed to determine the in vivo effects of intra-articular injections of CAPE on cartilage in an ...

The purpose of this study was to evaluate active knee flexion range of motion and hamstring strength following hamstring anterior cruciate ligament (ACL) reconstruction. Case control study, consecutive sample. Seventy-four consecutive patients who had undergone hamstring ACL reconstruction underwent isokinetic muscle strength testing at 2 years post surgery. Measurements of the maximum standing active knee flexion angle with the hip extended were also taken. During isokinetic testing, we evaluated flexion torque at 90 degrees of knee flexion, in addition to the peak flexion torque. We further compared these parameters of muscle strength around the knee for the patients in whom only semitendinosus tendon was harvested as a graft source (ST group), and those from whom the semitendinosus tendon and the gracilis tendon were harvested (ST/G group). Isokinetic testing showed that, in both the ST and ST/G groups, the knee flexor strength of the involved leg was less effectively restored at 90 degrees of knee flexion than at the angle at which the peak torque was generated. Conversely, no significant difference was seen in the side-to-side ratio in either the peak flexion torque or the 90 degrees flexion torque between the groups. The side-to-side ratio in mean maximum standing knee flexion angle was significantly lower in the ST/G group than in the ST group. This study suggests that the loss of knee flexor strength following the harvest of the hamstring tendons may be more significant than has been previously estimated. Furthermore, multiple tendon harvest may affect the range of active knee flexion.

Background: Studies have shown that women are at higher risk of sustaining noncontact anterior cruciate ligament (ACL) injuries in specific sports. Recent gait studies of athletic tasks have documented that gender differences in knee movement, muscle activation, and external loading patterns exist. The objective of this study was to determine in a knee cadaver model if application of female-specific loading and movement patterns characterised in vivo for a stop-jump task cause higher ACL strains than male patterns. Methods: Gender-specific loading patterns of the landing phase of the vertical stopjump task were applied to seven cadaver knees using published kinetic/kinematic results for recreational athletes. Loads applied consecutively included: tibial compression, quadriceps, hamstrings, external posterior tibial shear, and tibial torque. Knee flexion was fixed based on the kinematic data. Strain of the ACL was monitored by means of a differential variable reluctance transducer installed on the anteriormedial bundle of the ACL. Findings: The ACL strain was significantly increased (P < 0.05) for the female loading pattern relative to the male loading pattern after the posterior tibial shear force was applied, and showed a similar trend (P = 0.1) to be increased after the final tibial torque was applied.

Self-efficacy belief may be of major importance for the outcome of rehabilitation after sports-related injuries. A new instrument, the Knee Self-Efficacy Scale (K-SES), was used to evaluate the role of perceived self-efficacy in patients with an anterior cruciate ligament (ACL) injury. The purpose of this prospective exploratory study was to describe the patients' perceived self-efficacy at various times post-injury and surgery, respectively, for responsiveness of the K-SES and to correlate the K-SES score with the patients' subjective symptoms. The purpose was also to describe the influence of gender, age and physical activity on the patients' perceived self-efficacy. Thirty recently injured patients with an ACL-deficient knee and 33 patients who had undergone ACL reconstruction reported their physical activity level and their perceived self-efficacy on four test occasions during a 1-year period. The patients' subjective knee symptoms were documented on two of the test occasions. A significant increase in the K-SES score was seen after injury as well as after surgery, during the course of rehabilitation. Pre-operatively, men's perceived self-efficacy was significantly (P 5 0.013) higher compared with women's self-efficacy. Patients with a high baseline (pre-injury) physical activity level (Tegner 7-10) perceived their self-efficacy as being significantly (P 5 0.005) higher pre-operatively important for perceived self-efficacy according to and Crossman . found a relationship between self-efficacy and functional performance in older Scand J Med Sci Sports

Purpose To determine the most common rupture patterns of previously reconstructed DB-ACL cases, seen at the time of revision surgery, and to determine the influence of age, gender, time between the initial ACL reconstruction and re-injury, tunnel angle and etiology of failure. Methods Forty patients who presented for revision surgery after previous double-bundle ACL reconstruction were enrolled. Three orthopedic surgeons independently reviewed the arthroscopic videos and determined the rupture pattern of both the anteromedial and posterolateral grafts. The graft rupture pattern was then correlated with the previously mentioned factors.

Pain thresholds and levels of distress before and in the early postoperative period after anterior cruciate ligament surgery were measured in professional and amateur male soccer players and compared. Between June 2005 and March 2007, 30 soccer players (10 amateur, 20 professional) with acute or chronic tears of the anterior cruciate ligament who were scheduled for a bone-tendon-bone ACL reconstruction procedure were enrolled in the study. Measures of pain intensity, depression and anxiety were assessed 1 day pre-operation and 1 week and 3 weeks post-operation (T1 T2 and T3). Pain was assessed using a visual analog scale (VAS), depression with the Beck Depression Inventory (BDI), and anxiety with both the state and trait forms of the State-Trait Anxiety Inventory (STAI). Scores on the VAS, BDI, and STAI in both groups were analyzed. The mean VAS scores at T1 and T2 in professional players were not significantly higher than those in amateur players (P N 0.05). Professionals had significantly higher BDI scores at T1 and T2 (P b 0.05), but this difference was not significant at T3 (P = 0.12). High depression scores did not correlate with high pain scores.

We studied reconstruction of the anterior cruciate ligament (ACL) in skeletally mature goats. In one group, the autogenous tissue was augmented with polydioxanone (PDS), the other group had no augmentation. Histological complete incorporation and remodeling of the transplant was found in both groups. The newly formed connective tissues gradually assumed the microscopic properties of the normal ligament. The augmented group showed a delay in remodeling and maturation of the fiber bundles. Mechanically, the PDS-augmented transplants were stronger than the nonaugmented transplants immediately after surgery. During the first 6 weeks, a rapid decrease in strength of the augmented transplants was found, whereas the strength of the nonaugmented group gradually increased. The results of our experiment do not favor augmentation of autografts in reconstruction of the ACL.

Knowledge of the three-dimensional balance of loads at the knee joint is required to adequately assess the treatment and Ž . rehabilitation of the malfunctioning knee. This report focuses upon the moment arms for the knee in internalrexternal IE rotation motion. It augments prior work that defined flexionrextension moment arms. Muscle excursions and angular motion of the lower leg during IE rotation were measured in 17 fresh-frozen hemi-pelvis specimens. Moment arms were calculated as the derivatives of excursion with respect to the angle. Rotational motion was performed for the normal and anterior cruciate Ž . ligament ACL -deficient knee. Of the 13 muscles measured at the knee, seven were significant contributors to IE rotation: the biceps femoris long and short head externally rotate opposite the gracilis, sartorious, semimembranosis, semitendonosus and popliteus, functioning as internal rotators. Moment arm magnitudes were greatest with the knee in a flexed position Ž w x w x . internal external rotators peaked at 70Њ 90Њ flexion . At 30Њ flexion, the IE rotation moment arm minima and maxima were 10.1᎐11.6, 6.8᎐9.0, 6.0᎐15.7, 8.2᎐14.1 and 0.0᎐10.4 mm for the semimembranosis, semitendonosus, gracilis, sartorius and popliteus, and 14.7᎐27.9 and 18.5᎐31.5 mm for the biceps femoris short and long, respectively. Moment arms for the ACL-deficient condition were significantly changed only at extremes of flexion᎐extension. ᮊ

The purpose of our study was to clarify the events that take place during anterior cruciate ligament (ACL) failure, focusing on the behavior of the ACL as a composition of multiple fibers, during uniaxial tension along the ligament.Ten fresh-frozen human cadaveric knee specimens were fixed in an Instron machine (Instron, Norwood, MA), and load was applied parallel to the ACL axis. Two cameras were used to detect the failure mode of the ACL and its different groups of fibers. The distinct bundles of fibers were marked in each specimen before testing. The macroscopic findings during the experiment were used for comparison with the biomechanical results.The ACL showed a non-monotonic response during testing. The load-elongation curve showed a plateau or a second peak after the initial drop in load. Macroscopically, some fibers were failing initially, whereas the intact fibers had a remaining load potential. In our setting, 3 different failure patterns were recognized, specifically, a midsubstance tear of the anteromedial or the posterolateral bundle with a subsequent failure of the intact bundle or an initial avulsion of the anteromedial attachment. Analysis of the video frames showed a direct connection between the failure patterns in the load-elongation curves and the macroscopic sequence of events during ACL failure.The ACL ligament acts as a multifiber construction. In our setting, rupture follows 3 specific patterns where a complete or partial tear of the fiber bundles occurs first and the remaining intact fiber bundles have a potential load resistance.Our study allows a better understanding of the mechanical properties of the ACL. An update on the biomechanics of ACL failure during uniaxial tension after the “double-bundle revolution” could provide data helpful for ACL reconstruction.

Introduction: The aim of this study was to determine if using a direct kinematic (DK) or inverse kinematic (IK) modelling approach can influence the estimation of knee joint kinematics, kinetics and ACL injury risk classification during unanticipated side-cutting. Methods: Three-dimensional motion and force data of 34 amateur Australian rules footballers conducting unanticipated side-cutting manoeuvres were collected. The model used during the DK modelling approach was an eight segment lower body model with the hip, knee and ankle free to move in six degrees-of-freedom. During the IK modelling approach the same eight segment model was used, however translational constraints were imposed on the hip, knee and ankle joints. The similarity between kinematic and kinetic waveforms was evaluated using root mean square error and one-dimensional statistical parametric mapping (SPM1D). Classification of an athlete's ACL injury risk was determined by correlating their peak knee moments with a pre-defined injury risk threshold. Results: The greatest RMSE occurred in the frontal plane joint angles (RMSE: 10.86) and moments (RMSE: 0.67±0.18 N·m·kg -1 ), which were also shown to be significantly different in the SPM1D analysis. Both DK and IK modelling approaches classified the same athletes as being at 'high risk' of ACL injury. Conclusions: The choice of a DK or IK modelling approach affected frontal plane estimates of knee joint angles and peak knee moments during the weight acceptance phase of unanticipated side-cutting. However, both modelling approaches were similar in their classification of an athlete's ACL injury risk.

Background and Purpose. Little evidence supports the prescription of preoperative rehabilitation in the treatment of chronic anterior cruciate ligament-defi cient (ACLD) subjects. The aim of the present study was to assess the effectiveness of a specifi c six-week pre-operative exercise programme on ACLD knees. Method. A single, masked, controlled study was designed. This comprised two matched groups of 12 chronically ACLD patients awaiting reconstruction and a group of 12 matched uninjured control subjects. Only one ACLD group received a home-based exercise and educational programme. Assessment before and after the exercise intervention included: knee joint stability (clinical and KT1000 evaluation); muscle strength (Cybex II); standing balance and functional performance (agility, hop and subjective tests). Results. At the time of initial assessment there were no statistically signifi cant differences in any measures for the two ACLD groups but both ACLD groups were signifi cantly different from the uninjured control group as regards quadriceps strength and function. Measures taken after six weeks showed no signifi cant improvement in the untreated ACLD group or in the uninjured control group The treated ACLD group showed signifi cant improvement in the following measures: quadriceps strength measured at 60˚ and 120˚ per second (p < 0.001); single leg standing balance with eyes closed (p < 0.001); instrumented passive stability at 20 lb (89N) force (p = 0.003); agility and subjective performance (p < 0.001). The incidence of unstable episodes had decreased in the treated ACLD group, reducing further damage to the joint. Conclusion. This study leaves little doubt that pre-operative physiotherapy had a positive effect on motor function in ACLD subjects and should be prescribed routinely to maximize muscle stabilizing potential prior to reconstruction. Patients report improved stability and, in certain cases, may Chronic ACLD: effectiveness of home-based physiotherapy FIGURE 1: The sway meter, as used to assess single-leg balance with eyes open, eyes closed and on a foam surface.

Objective-To describe a method for radiographic measurement of the mechanical joint angles of the tibia in the sagittal plane and report reference ranges for a population of dogs with cranial cruciate ligament disease, and specifically for Labrador Retrievers. Study Design-Retrospective evaluation of radiographs. Animals-Canine tibia (n ¼ 150) of dogs evaluated for cranial cruciate ligament disease; 104 tibiae were from Labrador Retrievers, 46 tibiae were from other medium-to large-breed dogs. Methods-Medial-lateral radiographs were used to establish anatomic landmarks and measure the mechanical cranial distal tibial angle (mCrDTA) and mechanical caudal proximal tibial angle (mCaPTA). Results-For all tibiae mean mCrDTA was 81.61 and mCaPTA, 63.61. For Labrador Retriever tibiae mean mCrDTA was 81.71 and mCaPTA, 63.81. For non-Labradors, means mCrDTA was 81.51 and mCaPTA, 631. Labrador Retrievers were significantly younger than non-Labradors in our study population. No significant differences were noted between Labrador Retrievers and non-Labradors for mCrDTA or mCaPTA and correlations between mCrDTA and mCaPTA were neither strong nor significant. Conclusion-A method was established for radiographic measurement of mechanical joint angles of the canine tibia in the sagittal plane. Reference ranges are reported for a population of Labrador Retrievers and a population of non-Labradors with cranial cruciate ligament disease. Clinical Relevance-Measurement method and reference ranges provided for mechanical tibial angles may be used to aid in diagnosis, surgical planning, and postoperative critique for hindlimb angular deformities.

Background-Single-legged hop tests are commonly used functional performance measures that can capture limb asymmetries in patients after anterior cruciate ligament (ACL) reconstruction. Hop tests hold potential as predictive factors of self-reported knee function in individuals after ACL reconstruction. Hypothesis-Single-legged hop tests conducted preoperatively would not and 6 months after ACL reconstruction would predict self-reported knee function (International Knee Documentation Committee [IKDC] 2000) 1 year after ACL reconstruction. Study Design-Cohort study (prognosis); Level of evidence, 2. Methods-One hundred twenty patients who were treated with ACL reconstruction performed 4 single-legged hop tests preoperatively and 6 months after ACL reconstruction. Self-reported knee function within normal ranges was defined as IKDC 2000 scores greater than or equal to the ageand sex-specific normative 15th percentile score 1 year after surgery. Logistic regression analyses were performed to identify predictors of self-reported knee function within normal ranges. The area under the curve (AUC) from receiver operating characteristic curves was used as a measure of discriminative accuracy. Results-Eighty-five patients completed single-legged hop tests 6 months after surgery and the 1-year follow-up with 68 patients classified as having self-reported knee function within normal ranges 1 year after reconstruction. The crossover hop and 6-m timed hop limb symmetry index

Seventy-two patients with subacute or chronic rupture of the anterior cruciate ligament were randomly assigned to autograft reconstruction with four-strand gracilis and semitendinosus tendon (N = 37) or with patellar tendon-bone (N = 35) from the ipsilateral side. The groups were similar in terms of age, sex, level of activity, degree of laxity, meniscal lesions found surgically, and rehabilitation program. The follow-up was performed at another hospital by independent observers after 6, 12, and 24 months. Sixty-one patients (32 with hamstring tendon grafts and 29 with patellar tendon grafts) complied with the follow-up routine for the full 24 months. No differences were found between the groups with respect to Cincinnati functional score, KT-1000 arthrometer measurements, or stairs hopple test results. The subjective result and the single-legged hop test result were better for the hamstring tendon group after 6 and 12 months, but no differences were found after 24 months. The hamst...

The purpose of the study was to examine reproductbllity of knee laxity measurements obtained using the Dynamic Cructate Tester (OCT) from day-to-day, set-to-set. and trlal-to-trlal. In Part I. peak anterior Ubtal translation (Am was assessed for 1 anterior eructate Jtgament (ACL) defictent and 16 control subjects during two sets of three active trlals (maximal Isometric quadr1ceps cont.racttons) and three passive trlals (240 N load) conducted over four consecutive days. In Part Il, peak ATI was recorded for 12 chronic ACL deficient subjects during one set of five active and five passive trlals within one day. Results wereanalysed using mixed repeated measures ANOVA designs with tntraclass reliability coeffictents (ICC) calculated from the ANOVA results. There were no stgntftcant differences In the mean peak ATI results among the four tests days or between the two test sets conducted within a day. with ICC ranging from R 1 =0.939 to 0.980. It was concluded peak ATI measurements obtained using the OCT were reproducible from day-to-day and set-to-set. A stgntftcant main effectoftrtal was found on both active (F12,321 = 13.93: p < 0.001) and passive (F12.321 = 57.21: p < 0.001) peak ATI results. It was therefore recommended a full pretrial should be conducted before knee laxity assessment ustng the OCT to ensure reproducible results.

Purpose: Because a strong and stable knee is paramount to an athlete's or patient's success, an understanding of knee biomechanics while performing the squat is helpful to therapists, trainers, sports medicine physicians, researchers, coaches, and athletes who are interested in closed kinetic chain exercises, knee rehabilitation, and training for sport. The purpose of this review was to examine knee biomechanics during the dynamic squat exercise. Methods: Tibiofemoral shear and compressive forces, patellofemoral compressive force, knee muscle activity, and knee stability were reviewed and discussed relative to athletic performance, injury potential, and rehabilitation. Results: Low to moderate posterior shear forces, restrained primarily by the posterior cruciate ligament (PCL), were generated throughout the squat for all knee flexion angles. Low anterior shear forces, restrained primarily by the anterior cruciate ligament (ACL), were generated between 0 and 60°knee flexion. Patellofemoral compressive forces and tibiofemoral compressive and shear forces progressively increased as the knees flexed and decreased as the knees extended, reaching peak values near maximum knee flexion. Hence, training the squat in the functional range between 0 and 50°knee flexion may be appropriate for many knee rehabilitation patients, because knee forces were minimum in the functional range. Quadriceps, hamstrings, and gastrocnemius activity generally increased as knee flexion increased, which supports athletes with healthy knees performing the parallel squat (thighs parallel to ground at maximum knee flexion) between 0 and 100°knee flexion. Furthermore, it was demonstrated that the parallel squat was not injurious to the healthy knee. Conclusions: The squat was shown to be an effective exercise to employ during cruciate ligament or patellofemoral rehabilitation. For athletes with healthy knees, performing the parallel squat is recommended over the deep squat, because injury potential to the menisci and cruciate and collateral ligaments may increase with the deep squat. The squat does not compromise knee stability, and can enhance stability if performed correctly. Finally, the squat can be effective in developing hip, knee, and ankle musculature, because moderate to high quadriceps, hamstrings, and gastrocnemius activity were produced during the squat.

Background In 1982, the Lysholm score was first published as a physician-administered score in the American Journal of Sports Medicine. The Tegner activity scale was published in 1985. Hypothesis The Lysholm and Tegner scores are valid as patient-administered scores and responsive at early time points after treatment of anterior cruciate ligament tears. Study Design Cohort study (Diagnosis); Level of evidence, 1. Methods All patients were treated for an anterior cruciate ligament tear. For responsiveness, the Lysholm score (n = 1075) and Tegner activity level (n = 505) were measured preoperatively and 6, 9, 12, and 24 months postoperatively. For test-retest (n = 50), scores were measured at 2 years postoperatively and again within 4 weeks by questionnaire. For criterion validity (n = 170), patients completed the Short Form-12 and the International Knee Documentation Committee score in addition to Lysholm and Tegner instruments. For all other analyses, preoperative Lysholm score (n =...

Meniscal injuries are frequently associated with anterior cruciate ligament (ACL) tears. Clinical tests that are useful for detecting meniscal tears may not be valid in this setting. The Thessaly test, a newly described dynamic clinical examination, has been shown to have a very high diagnostic accuracy for detecting meniscal tears. This study evaluates the accuracy of the Thessaly test in patients with combined ACL and meniscus injuries. We examined eighty patients with ACL deficiency for meniscal injuries using the Thessaly test (at 20°of knee flexion), the lateral and medial joint line tenderness tests, and the McMurray test. Examiners were blinded to the MRI report on the conditions of the menisci. All patients underwent arthroscopic ACL reconstruction during which the menisci were evaluated by direct vision and probing. During the Thessaly test, six patients developed severe pain and could not complete the test. Sensitivity, specificity, likelihood ratios and predictive values were calculated for all tests. The Thessaly test had a sensitivity of 79%, specificity of 40%, positive predictive value of 56%, negative predictive value of 66%, positive likelihood ratio of 1.33, negative likelihood ratio of 0.51%, and overall accuracy of 60%. We concluded that the Thesally test has a low specificity in patients with combined ACL and meniscal injuries and can not be recommended as a diagnostic test in this setting.

Although decreased hip range of motion has been detected in many soccer players with noncontact anterior cruciate ligament (ACL), it is not clear whether it is associated with bone spurs, capsular soft tissue stiffness or both. Our aim was to investigate abnormal radiographic findings in soccer players with limited hip range of motion and noncontact ACL injury. Fifty consecutive male soccer players with restricted hip range of motion and noncontact ACL injury were subjected to radiographic examination to identify bone changes that could be associated with decreased hip range of motion. Of 50 patients, 56% revealed abnormal radiographic findings: pericapsular calcifications or acetabular rim osteophytes (24%), femoral neck deformity (10%), femoral neck and acetabular rim disorders (18%), neck groove caused by impingement (4%). Radiographic evaluation of those individuals showed a high number of bone abnormalities around the hip joint. This was considered to be an important finding to guide a decision-making process between three different approaches: changing the type of sports practiced, undergoing a more restrictive surgery (such as a double-bundle intraarticular reconstruction or an intra plus extra technique) or the onset of a hip-stretching program in addition to the conventional ACL rehabilitation protocol. In this last option, ACL-operated patients without radiographic hip abnormalities may have better outcomes for their decreased hip range of motion when submitted to a stretching program targeting the prevention of rotational overload on the reconstructed intra-articular grafts. The decision-making process concerning soccer players with ACL ruptures should take into consideration the amount of motionlimiting abnormalities around the hip joint.

Introduction The application of interference screws for the Wxation of bone-patellar tendon-bone (BPTB) grafts is a well-established technique in anterior-cruciate ligament reconstruction. Interference screws derived from bovine compact bone are a biological alternative to metallic or biodegradable polymer interference screws. Materials and methods In 60 porcine specimens, the tibial part of an anterior-cruciate ligament reconstruction was performed using a BPTB graft. To secure the graft, either an 8-mm titanium interference screw or a self-made bovine interference screw (BC), or a commercial bovine compact bone screw (TutoWx ® ) was used. The maximum failure load was determined by means of a universal testing machine with computer interface at a testing speed of 50 mm/min. In a second test series, cyclic sub-maximal load was applied to the test specimen from 40 to 400 N with a number of 1,000 load cycles and a frequency of 1 Hz. Subsequently, the maximum failure load was determined. The stiVness of the test specimen was investigated in both test series. Each type of interference screw was tested 10 times.

Purpose: The purpose of this study was to perform a systematic review of the available literature to define the level of quality evidence for determining the sensitivity and specificity of different radiographic views in detecting knee osteo-arthritis and to determine the impact of different grading systems on the ability to detect knee osteoarthritis. Methods: A systematic review of the literature was conducted to identify studies that evaluated the standing anteroposterior (AP) and 45 posteroanterior (PA) views for tibiofemoral and patellofemoral arthritis and those comparing the use of the Kellgren-Lawrence versus the joint space narrowing (JSN) radiographic grading systems using arthroscopy as the gold standard. A comprehensive search of PubMed, Scopus, CINAHL, the Cochrane Database, Clinicaltrial.gov, and EMBASE was performed using the keywords " osteoarthritis, " " knee, " " x-ray, " " sensitivity, " and " arthroscopy. " Results: Six studies were included in the evaluation. The 45 flexion PA view showed a higher sensitivity than the standing AP view for detecting severe arthritis involving either the medial or lateral tibiofemoral compartment. There was no difference in the specificities for the 2 views. The direct comparison of the Kellgren-Lawrence and the JSN radiographic grading systems found no clinical difference between the 2 systems regarding the sensitivities, although the specificity was greater for the JSN system. Conclusions: The ability to detect knee osteoarthritis continues to be difficult without using advanced imaging. However, as an inexpensive screening tool, the 45 flexion PA view is more sensitive than the standing AP view to detect severe tibiofemoral osteoarthritis. When evaluating the radiograph for severe osteoarthritis using either the Kellgren-Lawrence or JSN grading system, there is no clinical difference in the sensitivity between the 2 methods; however, the JSN may be more specific for ruling in severe osteoarthritis in the medial compartment. Level of Evidence: Level I, systematic review of Level I studies.

Objective: This study aimed to determine the effectiveness of virtual rehabilitation on balance and functionality in patients with anterior cruciate ligament (ACL) reconstruction. Methods: A total of 22 males who had undergone ACL reconstruction were divided into Nintendo and control groups. Both of the groups received six week accelerated rehabilitation in our department, and the Nintendo Wii© (Nintendo, Washington, USA) balance games were added to Nintendo group after three weeks for forty minutes a day, three times a week. Patients were evaluated for pain (visual analog scale), functionality (Lower Extremity Functional Scale), center of gravity (COG) and balance (Nintendo Wii©) at the baseline and end of the 3th and 6th week of rehabilitation program. Results: Similar improvements were determined in the pain, functionality, COG and balance scores of the two groups at the end of the treatment program and there were no significant differences between the groups in the amount of cha...

Abnormal patterns of cell death, including increased apoptosis, can influence homeostasis of ligaments and could be involved in the pathogenesis of cranial cruciate ligament (CCL) rupture. Increased nitric oxide (NO) production has been implicated as a stimulus to increased apoptosis in articular cartilage. This study investigated apoptotic cell death in ruptured canine CCL (CCL group, n = 15), in ruptured CCL of dogs treated with oral

Purpose Surgery involving arthroscopic reconstruction of the injured ligament is the gold standard treatment for torn anterior cruciate ligament (ACL). Recent studies support the hypothesis of biological self-healing of ruptured ACL. The aim of the study is to evaluate, in an animal model, the efficacy of a new technique, dynamic intraligamentary stabilization that utilizes biological self-healing for repair of acute ACL ruptures. Methods The ACL in 11 adult female white alpine sheep was transected and in 8 sheep reconstructed by dynamic intraligamentary stabilization. To enhance the healing potential, microfracturing and collagen were used in all animals. The contralateral, non-operated knees served as controls. At 3 months postkilling, all animals were submitted to magnetic resonance imaging and biomechanical and histological evaluation. Results No surgery-related complications were observed. Postoperatively, all animals regularly used the operated leg with full weight bearing and no lameness. At the time of killing, all animals exhibited radiological and histological healing of the transacted ACL. Biomechanical tests confirmed successful restoration of anteroposterior translation in the dynamic intraligamentary stabilization knees. Histological examination revealed dense scar tissue at the ends of the transected ligaments exhibiting hypercellularity and hypervascularization. Conclusion The dynamic intraligamentary stabilization technique successfully induced self-healing of ruptured ACL in a sheep model. Knee joints remained stable during the healing period allowing free range of motion and full weight bearing, and no signs of osteoarthritis or other intraarticular damage in the follow up were observed.

The focus of most anterior cruciate ligament reconstructions has been on replacing the anteromedial bundle and not the posterolateral bundle. Anatomic two-bundle reconstruction restores knee kinematics more closely to normal than does single-bundle reconstruction. Controlled laboratory study. Ten cadaveric knees were subjected to external loading conditions: 1) a 134-N anterior tibial load and 2) a combined rotatory load of 5-N x m internal tibial torque and 10-N x m valgus torque. Resulting knee kinematics and in situ force in the anterior cruciate ligament or replacement graft were determined by using a robotic/universal force-moment sensor testing system for 1) intact, 2) anterior cruciate ligament deficient, 3) single-bundle reconstructed, and 4) anatomically reconstructed knees. Anterior tibial translation for the anatomic reconstruction was significantly closer to that of the intact knee than was the single-bundle reconstruction. The in situ force normalized to the intact ante...

The literature has shown that anterior cruciate ligament (ACL) tear rates vary by gender, by sport, and in response to injury-reduction training programs. However, there is no consensus as to the magnitudes of these tear rates or their variations as a function of these variables. For example, the female-male ACL tear ratio has been reported to be as high as 9:1. Our purpose was to apply meta-analysis to the entire applicable literature to generate accurate estimates of the true incidences of ACL tear as a function of gender, sport, and injury-reduction training. Methods: A PubMed literature search was done to identify all studies dealing with ACL tear incidence. Bibliographic cross-referencing was done to identify additional articles. Meta-analytic principles were applied to generate ACL incidences as a function of gender, sport, and prior injury-reduction training. Results: Female-male ACL tear incidences ratios were as follows: basketball, 3.5; soccer, 2.67; lacrosse, 1.18; and Alpine skiing, 1.0. The collegiate soccer tear rate was 0.32 for female subjects and 0.12 for male subjects. For basketball, the rates were 0.29 and 0.08, respectively. The rate for recreational Alpine skiers was 0.63, and that for experts was 0.03, with no gender variance. The two volleyball studies had no ACL tears. Training reduced the ACL tear incidence in soccer by 0.24 but did not reduce it at all in basketball. Conclusions: Female subjects had a roughly 3 times greater incidence of ACL tears in soccer and basketball versus male subjects. Injury-reduction programs were effective for soccer but not basketball. Recreational Alpine skiers had the highest incidences of ACL tear, whereas expert Alpine skiers had the lowest incidences. Volleyball may in fact be a low-risk sport rather than a high-risk sport. Alpine skiers and lacrosse players had no gender difference for ACL tear rate. Year-round female athletes who play soccer and basketball have an ACL tear rate of approximately 5%. Level of Evidence: Level IV, therapeutic case series.

Injuries to the Anterior Cruciate Ligament (ACL) are becoming more frequent. Correspondingly there has been an increase in the number of ACL reconstructions performed, with more than 150,000 procedures documented annually in the United States. 1 This increase in primary ACL reconstructions almost certainly will lead to an increase in the number of revision procedures. A successful outcome after revision ACL reconstruction depends on many factors, including a comprehensive knowledge of the etiology of failure. There is no universally accepted definition of failure after ACL reconstruction. In most cases, however, the cause of failure may be grouped into one or a combination of the following: 1. Graft failure a. Pathologic laxity b. Clinical instability c. Nonfunctional or detrimental graft 2. Loss of motion

Forces, moments and stresses at the knee are dependent upon external and internal loading factors including muscle forces, segmental position and velocity, load carried, and the moment arms (mechanical advantage) of the muscletendon units. Requisite to prediction of forces and moments is a detailed understanding of effective moment arms throughout the knee range-of-motion (ROM). Existing muscle models for the knee are based upon limited static studies of only a few preserved specimens. The objectives of this report are to develop a comprehensive description of muscle-tendon moment arms for the normal knee and the anterior cruciate ligament (ACL)-minus knee during flexion-extension motion. Recent research results describe two nonorthogonal, nonintersecting axes of motion for the knee-one describing flexion-extension (FE) and the other longitudinal rotation (LR, equivalent to internal-external rotation). The effective flexion-extension moment arms of the muscles crossing the knee were developed with respect to the FE axis in 15 fresh, hemi-pelvis cadaver specimens. The normal moment arms for each of 13 muscles plus the patellar tendon exhibited variable, yet repeatable and recognizable patterns throughout the ROM. For most muscles there was no significant difference between the normal and ACL-minus moment arms. The results provide a basis for more accurate predictions of joint reaction forces and moments as well as useful knowledge for practitioners and therapists to assist in the assessment of muscle balance at the knee following injury, repair, and throughout rehabilitation.

Purpose: There is significant debate concerning the morbidity of hamstring harvest for use during anterior cruciate ligament (ACL) reconstruction. We hypothesized that harvest of the semitendinosus and gracilis tendons for ACL reconstruction would result in no measurable hamstring weakness, but that abnormalities of the semitendinosus and gracilis muscle would be observed on magnetic resonance imaging (MRI) scans. Type of Study: Case series. Methods: Nine patients undergoing ACL reconstruction with doubled semitendinosus and gracilis tendons had MRI cross-sectional area measurements of both limbs made from axial images and muscle contour was studied on coronal images at 3 and 12 months. The semitendinosus, semimembranosus, gracilis, sartorius, and biceps muscles were evaluated. Isokinetic testing was performed on the operative and nonoperative legs at 60°and 180°per second at 6 and 12 months postoperatively. Results: The gracilis cross-sectional area at 1 year averaged 2 cm 2 on the operative side and 3.7 cm 2 on the contralateral side. The semitendinosus averaged 2.1 cm 2 on the operative side and 6.6 cm 2 on the contralateral side at 1 year. Both of these differences were statistically significant (P Ͻ .05). In most cases, the semitendinosus muscle was retracted. Distally, the gracilis and occasionally the semitendinosus were blending with the gastrocnemius or sartorial fascia. The gracilis and semitendinosus in 1 case extended to near the original attachment site. Hamstring strength testing revealed a 26% deficit on the operative side at 60°/second at 6 months and 16% at 180°/second. At 12 months the mean 60°/second deficit was 21% and the deficit at 180°/second was 13%. Conclusions: At 1 year, the semitendinosus and gracilis muscles showed significant and persistent atrophy on the operative side and frequent retraction of the semitendinosus muscle belly. There were also hamstring strength deficits persisting at 1 year after the use of the tendons for ACL reconstruction. Level of Evidence: Level IV.