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