Patients With Failed Anterior Cruciate Ligament Reconstruction Have an Increased Posterior Lateral Tibial Plateau Slope: A Case-Controlled Study.

PURPOSE: To compare knee anatomical parameters of patients with failed anterior cruciate ligament reconstruction (ACL-R) with those of a control group of sex-matched patients with successful ACL-R. METHODS: Forty-three patients (34 male, 9 female) who experienced graft failure after ACL-R were enrolled in the failed group. These patients were matched to a control group of 43 patients who underwent primary ACL-R with a minimum follow-up of 24 months. On magnetic resonance imaging, the following parameters were evaluated: transepicondylar distance, lateral and medial femoral condyle widths, tibial plateau width, notch width index, and the ratio of width and height of the femoral notch, ratio between the height and depth of the lateral and medial femoral condyle, lateral and medial posterior tibial slopes, and anterior subluxation of the lateral and medial tibial plateau. Multivariate regression with backward elimination, including only the previously identified significant variables, defined the independent predictors for revision surgery. RESULTS: The anatomical variables that were significantly different between the 2 study groups were lateral and medial posterior tibial slopes, anterior subluxation of the lateral and medial tibial plateau, medial tibial plateau width, lateral tibial plateau width, medial femoral condyle width, and transepicondylar distance; however, the multivariate regression analysis identified the lateral posterior tibial slope (LTPs), the anterior subluxation of the medial tibial plateau, and the medial femoral condyle width as significant independent predictors (P < .05). The LPTs had the highest coefficient and the highest sensitivity (88%) and specificity (84%) to identify failures when considering the optimal cutoff value of 7.4°. CONCLUSIONS: Several anatomical parameters have been identified that differ significantly between patients with failed ACL-R and those without a documented failure. The most accurate predictor of ACL failure was an LTPs >7.4°, with a sensitivity of 88% and specificity of 84%. Surgeons should consider measuring LTPs during preoperative assessment of ACL-injured patients, and patients with values >7.4° should be considered at high risk of ACL-R failure. LEVEL OF EVIDENCE: Level III retrospective prognostic trial.

Anatomical features of tibia and femur: Influence on laxity in the anterior cruciate ligament deficient knee.

BACKGROUND: Until now, there has been a lack of in vivo analysis of the correlation between bony morphological features and laxity values after an anterior cruciate ligament (ACL) injury. METHODS: Forty-two patients who underwent ACL-reconstruction were enrolled. Static laxity was evaluated as: antero-posterior displacement and internal-external rotation at 30° and 90° of flexion (AP30, AP90, IE30, IE90) and varus-valgus rotation at 0° and 30° of flexion (VV0, VV30). The pivot-shift (PS) test defined the dynamic laxity. Using magnetic resonance imaging, we evaluated the transepicondylar distance (TE), the width of the lateral and medial femoral condyles (LFCw and MFCw) and tibial plateau (LTPw and MTPw), the notch width index (NWI) and the ratio of width and height of the femoral notch (N-ratio), the ratio between the height and depth of the lateral and medial femoral condyle (LFC-ratio and MFC-ratio), the lateral and medial posterior tibial slopes (LTPs and MTPs) and the anterior subluxation of the lateral and medial tibial plateau with respect to the femoral condyle (LTPsublx and MTPsublx). RESULTS: Concerning the AP30, LTPs (P=0.047) and MTPsublx (P=0.039) were shown to be independent predictors while for the AP90 only LTPs (P=0.049) was an independent predictor. The LTPs (P=0.039) was shown to be an independent predictor for IE90 laxity, while for the VV0 test it was identified as the LFCw (P=0.007). CONCLUSIONS: A higher antero-posterior laxity at 30° and 90° of flexion was found in those with a lateral tibial slope <5.5°.

Over-the-top ACL Reconstruction Plus Extra-articular Lateral Tenodesis With Hamstring Tendon Grafts: Prospective Evaluation With 20-Year Minimum Follow-up.

BACKGROUND: There are few published studies with very long-term follow-up of combined intra- and extra-articular anterior cruciate ligament (ACL) reconstruction. PURPOSE: To analyze clinical and radiographic outcomes of over-the-top ACL reconstruction plus extra-articular lateral tenodesis with autologous hamstrings at minimum 20-year follow-up. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Of 60 originally eligible patients who underwent over-the-top ACL reconstruction with double-stranded hamstring tendon (leaving intact graft tibial insertions) and extra-articular lateral plasty (performed with the remnant part of tendons), 52 were prospectively evaluated at a minimum 20-year follow-up (mean follow-up, 24 years; 41 men, 11 women; mean age at time of surgery, 25.5 ± 7.6 years). Twenty-nine patients were available for prospective evaluations: clinical (Lysholm, Tegner, and objective International Knee Documentation Committee [IKDC]), instrumented (KT-2000), and radiographic (standard, long-standing, and Merchant views). Subjective KOOS (Knee injury and Osteoarthritis Outcome Score) and objective inertial sensor pivot-shift analysis (KiRA) were carried out at final follow-up. Twenty-three patients were investigated by phone interview for subjective Tegner score and documented complications, rerupture, or revision surgery. RESULTS: At final follow-up, mean Lysholm score was 85.7 ± 14.6; median Tegner score, 4 (range, 3-5); sport activity resumption, 86.2%; and objective IKDC score, good or excellent in 86% of patients (31%, A; 55%, B). Only 3 of 26 patients (12%) had >5-mm manual maximum KT-2000 side-to-side difference. KiRA system documented positive pivot-shift (>0.9-m/s2 tibial acceleration side-to-side difference) in these 3 of 26 patients (12%). Statistically significant changes were as follows: decrease in Tegner score from 7 (range, 6-8) at 5-year follow-up to 4 (range, 3-5) at 10 years ( P < .0001) and decrease in Lysholm score from 96.1 ± 7.3 at 10-year follow-up to 85.7 ± 14.6 at 20 years ( P = .0003). Radiographic evaluation demonstrated significant difference of medial joint space between injured and healthy knees in patients with concomitant medial meniscectomy (n = 8, 3.2 ± 0.6 vs 5.0 ± 1.8 mm, P = .0114). No significant differences were reported regarding lateral or patellofemoral joint space. One patient (2%) experienced rerupture, with 3 of 52 (5.8%) having a contralateral ACL injury (excluded from KT-2000 and radiographic evaluations). Overall, 4 of 29 clinical failures (objective IKDC, KT-2000) and 1 rerupture among 52 patients were registered at final follow-up. CONCLUSION: Studied surgical technique demonstrated good results in laxity control at 20-year minimum follow-up. The lateral extra-articular plasty associated with ACL reconstruction did not generate lateral knee or patellofemoral osteoarthritis. The factor increasing osteoarthritis was meniscectomy.

Assessment of the pivot shift using inertial sensors.

The pivot shift test is an important clinical tool used to assess the stability of the knee following an injury to the anterior cruciate ligament (ACL). Previous studies have shown that significant variability exists in the performance and interpretation of this manoeuvre. Accordingly, a variety of techniques aimed at standardizing and quantifying the pivot shift test have been developed. In recent years, inertial sensors have been used to measure the kinematics of the pivot shift. The goal of this study is to present a review of the literature and discuss the principles of inertial sensors and their use in quantifying the pivot shift test.