2023 ISAKOS Biennial Congress ePoster
Lower Limb Performance and Biomechanical Asymmetries Patients Following Anterior Cruciate Ligament Reconstruction
Peter Edwards, PhD, Perth, WA AUSTRALIA
Nicholas Blackah, BSc, Perth, WA AUSTRALIA
Jay R. Ebert, PhD, Perth, WA AUSTRALIA
Peter T. Annear, FRACS(Orth), Swanbourne, WA AUSTRALIA
Ross Radic, MBBS FRACS (Ortho) FAOrthA, West Perth, WA AUSTRALIA
Perth Orthopaedic and Sports Medicine Research Institute, Perth, WA, AUSTRALIA
FDA Status Not Applicable
Summary
Patients 6 months following ACL reconstruction display biomechanical and performance deficits during bilateral and unilateral vertical jumps that are not picked up by traditional horizontal hop tests
ePosters will be available shortly before Congress
Abstract
Introduction
Comprehensive analyses of performance outcomes and movement strategies in patients following anterior cruciate ligament reconstruction (ACLR) are essential to guide rehabilitation and safe, and successful, return to sport (RTS). Residual between-limb deficits in physical performance are a possible contributing factor to poor outcomes and risk of re-injury after ACLR. Furthermore, vertical jump / hop tests are thought to better capture knee-related function over traditional horizontal hop tests. The aim of this study was to investigate post-surgery lower limb performance and biomechanics in patients post-ACLR, compared to their non-operative limb.
Methods
Twenty-four patients post-ACLR (mean age, 29.4; height, 1.75 m; weight, 78.8 kg) were evaluated at a mean of 6.4 months post-surgery. Bilateral and single-leg (SL) counter-movement jumps (CMJ) and were performed on dual force plates that independently recorded left and right vertical ground reaction forces at 1000Hz, whereby jump height and eccentric and concentric phase variables were assessed. A single-leg horizontal hop for distance (SLHD) was also recorded in both limbs. Patient-reported outcome measures (PROMs) including the IKDC2000 subjective knee score, the ACL-RSI and the Modified Cincinnati Knee Score were also collected. Paired samples t tests were used to examine between-limb and between-test differences. Cohens d effect sizes were calculated to interpret the magnitude of between-limb and between-test differences.
Results
Significant between-limb differences were observed in both the SLHD (mean difference [MD], 19.6 cm; 95% CI, 8.7 to 30.4; P=0.001) and the SLCMJ (MD, 2.7 cm; 95% CI, 0.98 to 4.42; P=0.004). Significant between-test differences were observed, with jump height in the SLCMJ displaying greater inter-limb asymmetry than the SLHD (MD, 11.0%; 95% CI, 1.08 to 20.91; P=0.031). Significant between-limb differences were present for both eccentric- and concentric-phase variables in the bilateral CMJ with large effect sizes seen in concentric impulse (effect size [ES], 0.73; 95% CI, 12.2 to 55.7; P=0.004) and moderate effect sizes seen in eccentric deceleration rate of force development (effect size [ES], 0.50; 95% CI, 35.8 to 988.2; P=0.037).
Conclusion
The SLCMJ was better able to detect functional limb asymmetry than the SLHD. Between-limb deficits in key eccentric and concentric loading parameters were present at 6 months post-ACLR indicating a compensatory offloading strategy to protect the involved limb during a simple jump task and should be a rehabilitation priority to ensure good recovery in lower limb function. Subsequent evaluations are required at 9 to 12 months are required to ascertain adequate recovery in lower limb function prior to RTS.