A canine hybrid double‐bundle model for study of arthroscopic ACL reconstruction

Development and validation of a large animal model for pre‐clinical studies of intra‐articular anterior cruciate ligament (ACL) reconstruction that addresses current limitations is highly desirable. The objective of the present study was to investigate a translational canine model for ACL reconstruction. With institutional approval, adult research hounds underwent arthroscopic debridement of the anteromedial bundle (AMB) of the ACL, and then either received a tendon autograft for “hybrid double‐bundle” ACL reconstruction (n = 12) or no graft to remain ACL/AMB‐deficient (n = 6). Contralateral knees were used as non‐operated controls (n = 18) and matched canine cadaveric knees were used as biomechanical controls (n = 6). Dogs were assessed using functional, diagnostic imaging, gross, biomechanical, and histologic outcome measures required for pre‐clinical animal models. The data suggest that this canine model was able to overcome the major limitations of large animal models used for translational research in ACL reconstruction and closely follow clinical aspects of human ACL reconstruction. The “hybrid double‐bundle” ACL reconstruction allowed for sustained knee function without the development of osteoarthritis and for significantly improved functional, diagnostic imaging, gross, biomechanical, and histologic outcomes in grafted knees compared to ACL/AMB‐deficient knees. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1171–1179, 2015.     

关节镜下前交叉韧带重建术后翻修的原因分析和治疗对策

目的：总结关节镜下前交叉韧带（ACL）重建术后翻修的原因及处理策略。方法2005年2月至2008年1月广州军区广州总医院收治14例因ACL重建失败而需要进行翻修手术的患者,其中术后再次创伤4例、移植物失效松驰7例、膝关节粘连活动受限2例、术后感染1例。对ACL完全断裂4例、松驰失张力7例患者行一期ACL重建术,其中8例骨隧道位置正常,采用空心钻钻过原有可吸收螺钉,重新建立骨隧道;另3例骨隧道位置错误者重新定位隧道。对2例膝关节粘连患者行粘连松解手术。对1例术后感染患者行关节镜病灶清理、关节腔冲洗引流术及抗生素治疗。结果随访时间29～73个月,平均43.4个月。均未发生再次关节粘连、伤口感染、移植物断裂等并发症。IKDC评分由术前C级4例、D级10例改善为术后A级11例、B级2例、C级1例;术后Lysholm膝关节功能评分为（89±9）分,较术前的（62±10）分明显提高（P＜0.05）。结论关节镜下ACL重建失败原因复杂,翻修难度较大。详细的术前评估和手术方案的设计对于保证翻修手术成功十分重要。     

Prospective randomized comparison of endobutton versus cross‐pin femoral fixation in hamstring anterior cruciate ligament reconstruction with 2‐year follow‐up

Background: To determine if there is a different clinical outcome after TransFix versus endobutton femoral fixation in hamstring anterior cruciate ligament (ACL) reconstruction. Methods: Twenty‐nine patients were randomized into either Endobutton (Smith & Nephew, Andover, MA, USA) (n= 13) or TransFix (Arthrex, Naples, FL, USA) (n= 16) femoral fixation in hamstring ACL reconstruction. The distal fixation was with a bioabsorbable interference screw. The evaluation methods were clinical history and examination, KT1000 arthrometry for laxity as well as the International Knee Documentation Committee (IKDC) scores over a 2‐year time frame. Results: There were no significant differences between the study groups preoperatively. For the 2‐year follow‐up, 11 patients in the Endobutton group and 13 patients in the TransFix group were available (greater than 80%). No statistical differences between the two groups were found at the 1‐ or 2‐year follow‐up examinations. At the 2‐year follow‐up, 72.7% of the Endobutton and 84.6% of the TransFix group patients were in the IKDC A or B categories. Additional procedures postoperatively occurred more frequently in the TransFix group. Conclusions: There were no significant differences in the results for either technique of femoral fixation. Level of Evidence: Level I.     

Lower limb kinematic alterations during drop vertical jumps in female athletes who have undergone anterior cruciate ligament reconstruction

The aim of this study was to determine if anterior cruciate ligament reconstructed (ACL‐R) female athletes exhibit altered lower limb kinematic profiles during jump landing when compared to a non‐injured age, sex, and activity matched control group. Fourteen ACL‐R and 14 non‐injured control subjects performed 3 vertical drop jump (DVJ) trials. Lower limb kinematics were recorded at 200 Hz. Peak and time‐averaged angular displacements were quantified and utilized for between‐group analysis. The ACL‐R group displayed altered hip joint frontal and transverse plane kinematic alterations, and knee joint frontal and sagittal plane kinematic alterations. Specifically the ACL‐R group displayed an increased adducted (p < 0.05) and internally rotated (p < 0.05) hip joint position, both peak and time‐averaged, following landing. The ACL‐R group also displayed a decreased adducted (p < 0.05) and flexed (p < 0.05) position of the knee joint following landing. The observed aberrant lower limb kinematics could pre‐dispose ACL‐R athletes to potential future knee joint injuries. Further studies are required to determine in a prospective manner whether such deficits increase the incidence of recurrent ACL injury, and whether specific sensorimotor protocols following ACL reconstruction can minimize these kinematic deficits. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:72–78, 2012     

Validation of GAITRite and PROMIS as high‐throughput physical function outcome measures following ACL reconstruction

New healthcare demands for quality measures of elective procedures, such as anterior cruciate ligament (ACL) reconstructive surgery, warrant the establishment of high throughput outcomes for high volume clinics. To this end, we evaluated the PROMIS and GAITRite as physical function outcome measures to quantify early healing and post‐operative complications in 106 patients at pre‐operative and 3, 10, 20 and 52 weeks post‐ACL reconstruction with bone‐tendon‐bone autograft, and compared the results to the current IKDC validated outcome measure. The results showed that both PROMIS and GAITRite were significantly quicker to administer versus IKDC (p < 0.0001). Additional advantages were that PROMIS and GAITRite detected a significant decrease in physical function at 3 weeks post‐operative, and a significant improvement at 10 weeks post‐operative versus pre‐operative (p < 0.001), which were not detected with IKDC. GAITRite was limited by a low ceiling that could not detect improvement of physical function beyond 20 weeks, while both PROMIS and IKDC detected significant improvement out to 52 weeks post‐operative (p < 0.001). Linear regressions demonstrated a significant relationship between IKDC and PROMIS, with a combined correlation value of 0.8954 (p < 0.001) for all time points. Finally, ROC curve analysis demonstrated that PROMIS is a diagnostic test for poor outcomes. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:793–801, 2014.     

Comparing 2-year outcomes of anterior cruciate ligament reconstruction using either patella-tendon or semitendinosus-tendon autografts: a non-randomised prospective study

PURPOSE: To compare the results of anterior cruciate ligament (ACL) reconstructions using either a patella-tendon autograft or a semitendinosus-tendon autograft. METHODS: Based on surgeon experience and preference, 68 patients underwent ACL reconstruction using either a quadruple-strand semitendinosus autograft (n = 34) or a central one-third bone-patella tendon-bone autograft (n = 34). Each patient was assessed preoperatively and postoperatively at 3, 6, and 24 months using the International Knee Documentation Committee (IKDC) knee score, Biodex muscle strength and endurance testing, and the KT1000 instrumented arthrometer test of knee laxity to anterior translation. All assessments at the 2-year follow-up were performed by the same physician and physiotherapist. RESULTS: While ACL reconstruction improved knee stability and IKDC knee scores significantly, there was no statistically significant difference between semitendinosus- and patella-tendon autograft reconstructions in terms of long-term knee score or laxity to anterior translation. Semitendinosus graft reconstruction was associated with less donor-site morbidity and hamstring weakness. Meniscectomy was associated with poorer long-term knee scores. CONCLUSION: ACL reconstruction is associated with a significantly better IKDC knee score and laxity measurement at 2-year follow-up. However, we were unable to demonstrate a significantly better long-term outcome in knee score or laxity to anterior translation with either a patella-tendon autograft or a semitendinosus-tendon autograft.     

Functional outcome of double-bundle anterior cruciate ligament reconstruction

Background/PurposeThe anterior cruciate ligament (ACL) is one of the most frequently injured ligaments in the knee joint and is generally treated by surgical reconstruction. A possible reason for the unsatisfactory nature of this reconstruction is that the complex function of the ACL is not reproduced by the traditional ACL reconstruction procedure, which replicates only a single bundle rather than the two separate bundles that form the original ACL. It has been suggested that re-establishment of the double-bundle anatomy of the ACL is crucial for obtaining a better restoration of the normal biomechanics of the knee and improving the knee's rotatory stability. The purpose of this study was to evaluate the authors' current double-bundle ACL reconstruction technique and assess the various functions of the anteromedial and posterolateral bundles.MethodsPatients were assessed for instability and laxity after a mean follow-up of 16 months (range, 12–26 months). The range of motion was measured and compared with the opposite normal knee. Clinical evaluation was performed using the modified Lysholm scoring scale, the Tegner activity scale, and the International Knee Documentation Committee (IKDC) rating system.ResultsThe study included 20 patients, 15 males and five females, with a mean age of 22.7 years (range, 18–29 years) at the time of surgery. Following the procedure described by Yasuda et al, double-bundle ACL reconstruction, which anatomically reproduces the anteromedial and posterolateral bundles using hamstring tendon grafts, was performed on patients under general anesthesia. The clinical results for the Lysholm rating system were good to excellent, being 71 points preoperatively and 94 postoperatively. The IKDC rating was 65% preoperatively and 92% postoperatively. All patients showed a negative pivot shifting test.ConclusionThe ACL not only is the primary restraint on anterior tibial translation but also contributes considerably to normal knee kinematics. Our study showed that the four-tunnel double-bundle ACL reconstruction provides significant advantages in terms of anterior and rotational stability as well as objective IKDC. The subjective measurement of postoperative functional results using either the Lysholm or the IKDC rating system revealed a promising outcome after a short follow-up period.     

Joint loads resulting in ACL rupture: Effects of age,sex, and body mass on injury load and mode of failure in a mouse model

Anterior cruciate ligament (ACL) tears are a common knee injury with a known but poorly understood association with secondary joint injuries and post‐traumatic osteoarthritis (OA). Female sex and age are known risk factors for ACL injury but these variables are rarely explored in mouse models of injury. This study aimed to further characterize a non‐surgical ACL injury model to determine its clinical relevance across a wider range of mouse specifications. Cadaveric and anesthetized C57BL/6 mice (9–52 weeks of age) underwent joint loading to investigate the effects of age, sex, and body mass on ACL injury mechanisms. The ACL injury load (whole joint load required to rupture the ACL) was measured from force‐displacement data, and mode of failure was assessed using micro‐dissection and histology. ACL injury load was found to increase with body mass and age (p < 0.001) but age was not significant when controlling for mass. Sex had no effect. In contrast, the mode of ACL failure varied with both age and sex groups. Avulsion fractures (complete or mixed with mid‐substance tears) were common in all age groups but the proportion of mixed and mid‐substance failures increased with age. Females were more likely than males to have a major avulsion relative to a mid‐substance tear (p < 0.01). This data compliments studies in human cadaveric knees, and provides a basis for determining the severity of joint injury relative to a major ACL tear in mice, and for selecting joint loading conditions in future experiments using this model. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1754–1763, 2017.

     

Abnormal tibial position is correlated to early degenerative changes one year following ACL reconstruction

Altered knee kinematics following ACL reconstruction may predispose patients to the development of early onset post‐traumatic osteoarthritis. The goal of our study was to examine the longitudinal interrelationship between altered tibial position relative to the femur and cartilage health measured by quantitative T_1ρ MRI. Twenty‐five patients with isolated unilateral ACL injury underwent kinematic and cartilage T_1ρ MRI at baseline prior to ACL reconstruction and then at 1‐year post‐reconstruction. Tibial position relative to the femur in the anterior–posterior plane was calculated as well as cartilage T_1ρ relaxation values in the injured and uninjured knee. At baseline prior to ACL reconstruction, the tibia was in a significantly more anterior position relative to the femur in the ACL deficient knee compared to the healthy contralateral knee. This difference was no longer present at 1‐year follow‐up. Additionally, the side–side difference in tibial position correlated to increased cartilage T_1ρ relaxation values in the medial compartment of the knee 1‐year post‐reconstruction. Altered tibial position following ACL reconstruction is correlated with detectable cartilage degeneration as soon as 1 year following ACL reconstruction. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1079–1086, 2015.     

Multiple arthroscopic debridement and graft retention in septic knee arthritis after ACL reconstruction: a prospective case–control study

Purpose

This study was undertaken to prospectively analyse, at a mean five-year follow-up, the clinical, functional, and radiographic outcomes in patients who developed postoperative acute septic knee arthritis following anterior cruciate ligament (ACL) reconstruction using hamstring autograft. We also assessed the effect of multiple arthroscopic debridement and graft retention on the functional outcomes in comparison with the matched control group.

Methods

From a consecutive case series of 2,560 ACL-injured patients who were treated with arthroscopic ACL reconstruction, we report on 24 cases with postoperative septic knee arthritis. These patients were individually matched for age, sex, comorbidity, body mass index (BMI) and preinjury Tegner activity scale in a ratio of 1/1. Clinical, laboratory, synovial fluid analysis and culture were performed. Arthroscopic debridement and graft retention was done for all cases, in addition to antibiotic therapy IV. A detailed physical examination, KT1000 laxity testing, Lysholm knee score, Tegner activity level scale, International Knee Documentation Committee (IKDC), and Knee Injury and Osteoarthritis Outcome Score (KOOS) were completed.

Results

In all cases, treatment of infection was successful after a median of three (range one to six) repeated arthroscopic graft debridement and retention, in addition to antibiotic therapy IV. At an average of five years follow-up, two patients had over five millimetres manual maximum side-to-side difference in laxity. There were no significant differences between groups regarding Lysholm score, IKDC and KOOS. Median final Tegner activity score was 5.5 versus 7 in the control group (p = 0.004). Complications included graft rupture in three patients, loss of range of motion in five, Sudeck’s atrophy in one and moderate joint narrowing in two. There were no recurrences of septic arthritis or bone infection.

Conclusion

Graft retention seems not only possible but appropriate in view of the experience presented in this article for postoperative septic knee arthritis using hamstring autograft. A potential residual complication is arthrofibrosis, which deserves maximum attention.     

Arthrofibrosis following ACL reconstruction—reasons and outcome

Introduction Arthrofibrosis is a complication that severely influences the clinical outcome after anterior cruciate ligament (ACL) reconstruction. This retrospective clinical study analyses risk factors and outcome after arthrolysis in a large population.Material and methods Two hundred twenty-three patients who had undergone arthrolysis after ACL reconstruction were examined. Range of motion (ROM) was reduced due to arthrofibrosis of the joint in 70% (n=156). Other reasons, such as cyclops syndrome or osteoarthritis were found in 30% (n=67). The mean time interval between arthrolysis and follow-up was 4.29 years. We recorded timing of surgery, additional injuries, state of the knee before reconstruction, range of motion, pain during rehabilitation, beginning, duration and type of rehabilitation, severity and etiology of joint stiffness and the time between ACL reconstruction and revision. The present state of the knee was documented using the IKDC form.Results A significant correlation of arthrofibrosis and preoperative irritation (p<0.001), preoperative limited ROM (p=0.001), perioperative pain (p=0.046) and early beginning of muscle training (p=0.064) was found. Combination of a remaining loss of extension and development of degenerative joint disease was also significant (p=0.001). The decrease of sports activity compared with the level before ACL injury was highly significant (p<0,001). The criteria to minimize the risk of arthrofibrosis and the optimal timing of arthrolysis are pointed out.     

保留并牵张残留纤维的前十字韧带双束重建术

目的 评估在亚急性期进行保留并牵张残留纤维的前十字韧带双束重建的临床效果.方法 2006年1月至2006年6月,对56例前十字韧带损伤患者在亚急性期进行保留并牵张残留纤维的前十字韧带双束重建.前十字韧带双束重建采用四隧道八股肌腱移植的方法.使用PDS缝线穿缝胫骨侧残留纤维,经深束股骨隧道牵张固定.使用IKDC及Lysholm评分标准评估疗效.结果 53例随访2年以上.末次随访时所有患者Lachman试验均为阴性.屈膝25°KT-1000检测结果显示双侧膝关节松弛度差值为(-0.44±1.53)mm,与术前(8.01±1.83)mm比较差异有统计学意义(t=37.03,P=0.0001).29例(54.7%)双侧膝关节松弛度差值小于0mm,提示患膝相对于健侧更为稳定或紧张.24例(45.3%)双侧膝关节松弛度差值为0～2mm.所有患者轴移试验均阴性.48例膝关节活动度正常,2例有5°屈曲受限,1例有小于5°屈曲受限,2例有5°过伸受限.根据IKDC评估标准,51例(96.2%)正常,2例(3.8%)接近正常.IKDC主观评分为(95.6±3.1)分,Lysholm评分为(94.8±2.9)分.受伤前Tegner评分平均为7.3分,末次随访时为7.1分.结论 根据2年以上随访结果,以IKDC为评估标准,保留并牵张残留纤维的前十字韧带双束重建能够使96.2%的患者恢复正常,3.8%的患者接近正常.     

Gender differences in passive knee biomechanical properties in tibial rotation

The anterior cruciate ligament (ACL) is the most commonly injured knee ligament with the highest incidence of injury in female athletes who participate in pivoting sports. Noncontact ACL injuries commonly occur with both internal and external tibial rotation. ACL impingement against the lateral wall of the intercondylar notch during tibial external rotation and abduction has been proposed as an injury mechanism, but few studies have evaluated in vivo gender‐specific differences in laxity and stiffness in external and internal tibial rotations. The purpose of this study was to evaluate these differences. The knees of 10 male and 10 female healthy subjects were rotated between internal and external tibial rotation with the knee at 60° of flexion. Joint laxity, stiffness, and energy loss were compared between male and female subjects. Women had higher laxity (p = 0.01), lower stiffness (p = 0.038), and higher energy loss (p = 0.008) in external tibial rotation than did men. The results suggest that women may be at greater risk of ACL injury resulting from impingement against the lateral wall of the intercondylar notch, which has been shown to be associated with external tibial rotation and abduction. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:937–944, 2008     

Arthroscopic anatomic double bundle anterior cruciate ligament reconstruction: Our experience with follow-up of 4 years

BackgroundDouble bundle (DB) anterior cruciate ligament (ACL) reconstruction has been proposed to recreate the natural anatomy of ACL. Reconstruction of the anatomy of both the bundles of ACL has been thought to be able to restore the rotational stability of the knee joint. Nevertheless, it remains unclear whether DB reconstruction has better functional outcome than single bundle (SB) ACL reconstruction.PurposeTo evaluate the clinical outcomes, patient satisfaction and manual laxity tests of knee in patients treated with DB ACL reconstruction in Indian population.MethodsWe prospectively followed 25 patients with an isolated ACL injury operated for DB ACL reconstruction after applying the inclusion and exclusion criteria. Patients were evaluated pre-operatively and in the post-operative period at regular intervals with the minimum follow up of 4 years. Clinical stability was assessed by anterior drawer test, Lachman test and pivot shift test. Functional outcome was assessed by IKDC, Lysholm and Modified Cincinnati scores.ResultsAt the end of 4 years, functional outcome in terms of all subjective scores was satisfactory. Graded stability results of the Lachman, Anterior drawer and pivot shift tests were almost near to that in normal knee. No complication occurred post-operatively.ConclusionAnatomical DB ACL reconstruction seems to offer satisfactory results in terms of subjective scores and stability tests to patients with ACL tear. It has been found to be associated with no obvious complications and no failures. However a larger patient pool is desired for conclusive results.     

Reconstruction of the anterior cruciate ligament: a clinical comparison of bone-patellar tendon-bone single bundle versus semitendinosus and gracilis double bundle technique

The study hypothesis was that the outcome of semitendinosus gracilis double bundle (STG-DB) anterior cruciate ligament (ACL) reconstruction is advantageous in terms of clinical results and restoration of anterior-posterior and rotational laxity in comparison to bone-patellar tendon-bone single-bundle (PTB-SB) ACL reconstruction. We analysed 41 PTB-SB and 51 STG-DB patients using the Tegner, IKDC and WOMAC scores preoperatively and at a minimum follow-up of two years. At follow-up, there was no significant difference in the clinical scores. The KT 1000 side-to-side measurement showed no significant difference between groups. The STG-DB group was significantly superior in terms of the pivot-shift sign and anterior knee pain. We conclude that the outcome of STG-DB reconstruction in the mid-term was not advantageous in terms of clinical scores and anterior-posterior laxity evaluated by the KT 1000. Nevertheless, the restored rotational laxity measured by the pivot shift test was significantly superior in the STG-DB technique.     

Autografts vs Synthetics for Cruciate Ligament Reconstruction: A Systematic Review and Meta‐Analysis

To describe the outcomes of autografts and synthetics in anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) reconstruction with respect to instrumented laxity measurements, patient‐reported outcome scores, complications, and graft failure risk. We searched PubMed, Cochrane Library, and EMBASE for published randomized controlled trials (RCT) and case controlled trials (CCTs) to compare the outcomes of the autografts versus synthetics after cruciate ligament reconstruction. Data analyses were performed using Cochrane Collaboration RevMan 5.0. Nine studies were identified from the literature review. Of these studies, three studies compared the results of bone–patellar tendon–bone (BPTB) and ligament augmentation and reconstruction system (LARS), while six studies compared the results of four‐strand hamstring tendon graft (4SHG) and LARS. The comparative study showed no difference in Lysholm score and failure risk between autografts and synthetics. The combined results of the meta‐analysis indicated that there was a significantly lower rate of side‐to‐side difference > 3 mm (Odds Ratio [OR] 2.46, 95% confidence intervals [CI] 1.44–4.22, P = 0.001), overall IKDC (OR 0.40, 95% CI 0.19–0.83, P = 0.01), complications (OR 2.54, 95% CI 1.26–5.14, P = 0.009), and Tegner score (OR ?0.31, 95% CI ?0.52–0.10, P = 0.004) in the synthetics group than in the autografts group. This systematic review comparing long‐term outcomes after cruciate ligament reconstruction with either autograft or synthetics suggests no significant differences in failure risk. Autografts were inferior to synthetics with respect to restoring knee joint stability and patient‐reported outcome scores, and were also associated with more postoperative complications.     

Long-term results of anterior cruciate ligament reconstruction: a comparison with non-operative treatment with a follow-up of 17–20 years

Purpose

The aim of our study was to review the clinical and radiological outcome of patients who had undergone anterior cruciate ligament (ACL) reconstruction in comparison to a group of non-operatively treated patients.

Methods

In a retrospective study we compared ACL reconstruction using a bone-patellar tendon-bone graft with a non-operatively treated group of patients 17–20 years later. Fifty-four patients that met the inclusion criteria, with arthroscopically proven ACL rupture, were treated between 1989 and 1991. Thirty-three patients underwent ACL reconstruction, forming group one. Eighteen non-reconstructed patients continued with rehabilitation and modification of activities (group two). The International Knee Documentation Committee (IKDC) subjective and objective evaluation forms and the Lysholm and Tegner scale were used to assess the knees at follow-up. Radiographic assessment was performed using the IKDC grading scale.

Results

Follow-up results showed that 83% of reconstructed patients had stable knees and normal or nearly normal IKDC grade. Patients in the non-reconstructed group had unstable knees with 84% having abnormal or severe laxity. The subjective IKDC score was significantly in favour of group one: 83.15 compared to 64.6 in group two. The Lysholm and Tegner score was also significantly better in group one. Conservatively treated patients all had unstable knees and worse scores. The rate of osteoarthritis showed more severe changes in non-reconstructed patients with additional meniscus injury.

Conclusions

We can conclude that 94% of patients who underwent ACL reconstruction had stable knees after 15–20 years and there was a significantly lower percentage of osteoarthritis in comparison to conservatively treated patients.     

Anterior cruciate ligament reconstruction and physiological joint laxity: earliest changes in joint stability and stiffness after reconstruction

Physiological joint laxity is an important element of normal knee joint function, providing smooth joint movement. However, the objective evaluation of post-operative results after knee ligament surgery is usually based primarily on stability and range of motion, and joint laxity has been ignored. In this study, we measured the joint stiffness of 82 knees undergoing anterior cruciate ligament (ACL) reconstruction with the Leeds-Keio artificial ligament, before the operation, immediately after the operation, and finally when the full range of motion was achieved postoperatively; changes in joint laxity after the ACL reconstruction were investigated. Before the operation, joint laxity was greater than that of the normal side (P < 0.01), but immediately after the operation it diminished compared not only with that observed preoperatively, but also with that of the normal side. When the full range of motion was achieved, joint laxity was lower than that observed immediately after the operation (P < 0.01), but still remained higher than that of the normal side (P < 0.01). In other words, stability was achieved, but joint laxity was diminished through the operation. In this series, a stiffer artificial ligament than the natural ACL was used, and maximum tension was applied during the operation, aiming at better stability, but this may cause diminution of joint laxity. Received for publication on Sept. 1998; accepted on Dec. 2, 1998     

No difference between mechanical perturbation training with compliant surface and manual perturbation training on knee functional performance after ACL rupture

Manual perturbation training improves dynamic knee stability and functional performance after anterior cruciate ligament rupture (ACL‐rupture). However, it is limited to static standing position and does not allow time‐specific perturbations at different phase of functional activities. The purpose of this study was to investigate whether administering mechanical perturbation training including compliant surface provides effects similar to manual perturbation training on knee functional measures after an acute ACL‐rupture. Sixteen level I/II athletes with ACL‐ruptures participated in this preliminary study. Eight patients received mechanical (Mechanical) and eight subjects received manual perturbation training (Manual). All patients completed a functional testing (isometric quadriceps strength, single‐legged hop tests) and patient‐reported measures (Knee Outcome Survey‐Activities of Daily Living Scale (KOS‐ADLS), Global Rating Score (GRS), International Knee Documentation Committee 2000 (IKDC 2000) at pre‐ and post‐training. 2 × 2 ANOVA was used for data analysis. No significant group‐by‐time interactions were found for all measures (p > 0.18). Main effects of time were found for single hop (Pre‐testing: 85.14% ± 21.07; Post‐testing: 92.49% ± 17.55), triple hop (Pre‐testing: 84.64% ± 14.17; Post‐testing: 96.64% ± 11.14), KOS‐ADLS (Pre‐testing: 81.13% ± 11.12; Post‐testing: 88.63% ± 12.63), GRS (Pre‐testing: 68.63% ± 15.73; Post‐testing: 78.81% ± 13.85), and IKDC 2000 (Pre‐testing: 66.66% ± 9.85; Post‐testing: 76.05% ± 14.62) (p < 0.032). Administering mechanical perturbation training using compliant surfaces induce effects similar to manual perturbation training on knee functional performance after acute ACL‐rupture. The clinical significance is both modes of training improve patients' functional‐performance and limb‐to‐limb movement symmetry, and enhancing the patients’ self‐reported of knee functional measures after ACL rupture. Mechanical perturbation that provides a compliant surface might be utilized as part of the ACL rehabilitation training. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1391–1397, 2018.

     

Does Severity or Specific Joint Laxity Influence Clinical Outcomes of Anterior Cruciate Ligament Reconstruction?

It generally is believed generalized joint laxity is one of the risk factors for failure of anterior cruciate ligament (ACL) reconstruction. However, no consensus exists regarding whether adverse effects on ACL reconstruction are attributable to joint-specific laxity or are related to the severity of generalized joint laxity. We therefore asked whether knee stability and functional outcomes would be related to joint-specific laxity and would differ according to the severity of generalized joint laxity. The Beighton and Horan criteria were used to assess joint laxity in 272 subjects. All elements are added to give an overall joint laxity score ranging from 0 to 5. Knee translation did not increase in proportion to the severity of the generalized joint laxity. Patients with scores less than 4 showed similar knee stability. When all variables, including the severity of generalized joint laxity, were considered, only hyperextension of the knee independently predicted knee stability and function. In patients with knee hyperextension, a bone-patellar tendon-bone autograft provided superior stability and function compared with a hamstring tendon autograft. Our data suggest knee hyperextension predicts postoperative stability and function regardless whether patients have severe generalized joint laxity.