ECSS Paris 2023: OP-MH03
INTRODUCTION: Anterior Knee Laxity (AKL) evaluation is a common method in clinical practice for diagnosing anterior cruciate ligament (ACL) tear and assessing post-operative outcomes after surgical restoration. AKL is usually measured during physical examination through manual manoeuvres. However, this assessment can suffer from subjective interpretation of the tibiofemoral displacement. For this reason, research has proposed that instrumented static laxity evaluation through arthrometer devices can provide objective data useful for longitudinal assessment of clinical outcomes. Accordingly, this study aimed to assess differential AKL and compliance (C) in ACL deficient patients from pre-surgery to 6 months post-reconstruction follow-up, to investigate longitudinal changes within each sex and cross-sectional differences between males and females at baseline and at 6-month follow-up. METHODS: This was a retrospective study of prospectively collected data. Surgical procedures were performed by a single surgeon (R.C.) in a single center. All 56 patients (males: 41, females: 15; age: 30.3±12.91), operated between 2022 and 2024, had a complete ACL rupture confirmed during the arthroscopic surgery. An arthrometer device (GNRB, Genourob, Laval, France) was used to measure anterior-posterior AKL and C at a pre-operative baseline and at 6-month follow-up. Side-to-side differences (pathological–healthy) were calculated to obtain differential laxity (dL, in mm) at 134 N and differential compliance (dC, in µm/N). Longitudinal changes for differential outcomes were analyzed with a paired t test, while cross-sectional comparisons between females and males were performed using independent samples t test. Corresponding non-parametric tests were applied when necessary. Effect sizes are reported as Cohen’s d or rank biserial correlation (rbc). RESULTS: At follow-up both dL (baseline: 4.1±2 vs 6-month: 0.28±1.27; p<0.001; d=1.74) and dC (baseline:16.43±14.20 vs 6-month: 0.02±9.31; p<0.001; rbc= 0.9) were significantly reduced for the overall sample. Similar results were obtained when subgroup analysis by sex were performed with both males and females showing p<0.001, with comparable effect sizes. No differences between sexes were observed at baseline or follow-up for either differential outcome (all p>0.05). At baseline 35.7% of patients had dL<3 mm and 33.9% had dC <10 µm/N. At follow-up 100% of patients had dL<3mm and 89.3% had dC<10 µm/N. CONCLUSION: At follow-up, dL and dC were significantly reduced in both sexes with large effect sizes, supporting the biomechanical effectiveness of ACL reconstruction. Prior literature indicates females may present greater absolute laxity. Because this study computed side-to-side differences, this normalization may have attenuated potential sex-related differences. As not all patients exceeded the commonly accepted cut-offs for complete ACL tear at baseline (dL>3mm, dC >10 µm/N) we suggest integrating AKL measurements with patient history and other clinical examinations.
Read CV Giuseppe DAmicoECSS Paris 2023: OP-MH03
INTRODUCTION: The decision to perform a lateral extra-articular tenodesis (LET) alongside anterior cruciate ligament reconstruction (ACLR) is an important factor in reducing ACL re-rupture rates[1]. Although effective in reducing re-rupture rates, the LET procedure comes at the cost of increased surgery time, increased pain, a possible decreased range of motion of the knee and could increase the risk of osteoarthritis in the lateral compartment[2]. Hence, it is important to identify the cases that would benefit from a LET. To this end, we developed a machine learning based LET score, identified the key patient characteristics that influence this score and showed the potential of the LET score to identify re-rupture cases within a cohort that received ACLR without LET. METHODS: A retrospective analysis was conducted on 547 patients who underwent ACLR between January 2021 and March 2024. Demographic, clinical and radiological data, including age at surgery, pivot shift test results and posterior tibial slope (PTS), were collected. Five machine learning models, including Random Forest and XGBoost, were trained using a 10-fold cross-validation approach. SHAP (Shapley Additive Explanations) values were computed to quantify the contribution of individual features to the LET score. RESULTS: The Random Forest and XGBoost models achieved high predictive performance, with an AUC of 0.90 ± 0.02, demonstrating their reliability in predicting LET decisions. The key factors influencing LET predictions included high-grade pivot shift tests, younger age at surgery, and revision procedures, with these characteristics contributing up to 30% to the LET score. Patients who experienced re-ruptures within two years had significantly higher predicted LET scores compared to those without re-ruptures (mean score: 0.49 vs. 0.23 respectively, p=0.011 ± 0.01). These results suggest that the machine learning models potentially captured latent risk factors associated with re-rupture, beyond the explicit decision labels provided by surgeons. CONCLUSION: The machine learning models demonstrated high performance in predicting LET decisions and identified key characteristics of patients that influence surgical outcomes. These findings provide a quantitative framework for optimising LET decisions, potentially reducing re-rupture rates. Future studies should validate these models across diverse datasets to improve generalisability and clinical applicability. References 1. Getgood, A. M. J. et al. Lateral Extra-articular Tenodesis Reduces Failure of Hamstring Tendon Autograft Anterior Cruciate Ligament Reconstruction: 2-Year Outcomes From the STABILITY Study Randomized Clinical Trial. Am. J. Sports Med. 48, 285–297 (2020). 2. Castoldi, M. et al. A Randomized Controlled Trial of Bone–Patellar Tendon–Bone Anterior Cruciate Ligament Reconstruction With and Without Lateral Extra-articular Tenodesis: 19-Year Clinical and Radiological Follow-up. Am. J. Sports Med. 48, 1665–1672 (2020).
Read CV Jasper VolmerECSS Paris 2023: OP-MH03
INTRODUCTION: Restoring lower-limb function and ensuring a safe return to sports remain the primary challenges following anterior cruciate ligament reconstruction (ACLR). While isokinetic peak torque is a traditional gold standard for assessment, recent evidence suggests that the ability to develop force rapidly (rate of torque development, RTD) is often more critical than maximal strength for athletic tasks. Countermovement jumps (CMJ) and drop jumps (DJ) have been widely used to assess performance in individuals with ACLR. Force plate parameters could demonstrate responsiveness to changes in neuromuscular function, and detect any functional deficits. The Purpose of this study was to investigate the relationship between clinical strength metrics (isokinetic strength and isometric RTD) and jumping performance measured via force-plate kinetics in individuals following ACLR. METHODS: A total of 17 participants (8 males, 9 females) with a mean age of age: 29.09 +/- 7.85 years were enrolled in this study. The average follow-up time was 12.06 +/- 9.71 months (range 6.0~42.8 months). Isokinetic knee extension/flexion strength (60 deg/s and 180 deg/s) and RTD (100ms and 200ms) were measured; CMJ and DJ were evaluated through Hawkin Dynamics dual wireless force plates (Hawkin Dynamics, Westbrook, ME, USA), captured real-time kinetic data. Paired t-test and Wilcoxon Signed-Rank Test were employed to compare isokinetic strength and isometric RTD between limbs respectively. The relationship between strength/RTD and jump performance metrics was evaluated using Pearson correlation and Spearman's Rank Correlation. All significance levels were set at p < .05. RESULTS: Isokinetic peak torque for both knee extension and flexion were significantly lower in the affected limb compared to the contralateral limb across both testing velocities. All these Isokinetic strength parameters demonstrated a high positive correlation with jump height of CMJ and DJ, and also mRSI of the DJ. The Braking RFD during CMJ was significantly correlated specifically with knee extension isokinetic strength at 180 deg/s. (r = .56, p = .019) The RTD (100ms and 200ms) of the both knee flexors was significantly correlated with jump height of CMJ. The inter-limb symmetry of Peak Landing Force during the CMJ was significantly correlated with the symmetry of isokinetic knee flexion strength. (60 deg/s: r = .493, p = .044; 180 deg/s: r = .483, p = .049) CONCLUSION: Restoring isokinetic strength and RTD is essential for recovering jump height and propulsive symmetry post-ACLR. The correlation between high-velocity isokinetic strength and braking RFD suggests that rehabilitation should emphasize the ability to generate force rapidly. The specific link between knee flexor symmetry and landing force symmetry underscores the importance of hamstring rehabilitation for impact attenuation. Rehabilitation should target both maximal strength and rapid force production to ensure comprehensive functional recovery and safer return to sport.
Read CV TSANG-YU FANECSS Paris 2023: OP-MH03