nterlimb Asymmetry of Vertical Ground Reaction Force as a Risk Factor for Re-injury and Knee Osteoarthritis Following Anterior Cruciate Ligament Reconstruction: A Systematic Review

Background: Anterior cruciate ligament (ACL) reconstruction is performed as the gold standard of care for patients with ACL rupture. ACL reconstruction provides successful clinical outcomes, however, it cannot repair faulty lower limb mechanics. The loading asymmetry between right and left limbs during movement is often used to measure the effectiveness of surgical interventions and the potential risks of re-injury. Objectives: This study aims to evaluate the interlimb asymmetry of vertical ground reaction in patients with ACL reconstruction. Methods: An online search was done in the following databases: Science Direct, Scopus, PubMed, and Google Scholar. Then, studies from 2000 to 2022 were extracted. Selected articles were screened in a 4-step process according to the inclusion and exclusion criteria. Two researchers evaluated the methodological quality of the articles with the modified Downs and Black checklist. Finally, studies were classified into 3 categories: low (< 40%), medium (40% - 69%), and high quality (≥ 70%). Results: Finally, 9 studies were selected for the systematic review. The average methodological quality was 68.33% (range 54% - 80%), which shows the medium quality of the studies. A total of 4 articles had high methodological quality and 5 articles had medium quality. The results of 8 studies reported asymmetric vertical ground reaction force after ACL reconstruction. Only 1 study reported no significant difference in the asymmetrical vertical ground reaction force. Conclusion: Patients undergoing ACL reconstruction have knee flexion limitation and decreased quadriceps muscle strength. Eventually, this mechanism of energy absorption by the active tissue decreases, and mainly the shock absorption by the passive tissue increases. As a result, this mechanism leads to ACL re-injury and tibiofemoral joint cartilage damage.