Purpose: Anterior cruciate ligament (ACL) injury and reconstruction significantly increase the risk of knee osteoarthritis (OA). Biomechanical alterations during walking are frequently suggested contributors to OA development. This systematic review aims to determine the association between walking gait biomechanical changes following ACL injury or reconstruction and the early development of knee OA.
Methods: Studies were identified from MEDLINE, Web of Science, CINAHL and SPORTDiscus databases searched up to January 2024. Eligible studies included adults (≥15 years) with ACL injury or reconstruction, assessing knee biomechanics during walking compared to healthy controls or the contralateral limb. Outcomes included cartilage changes assessed through imaging techniques or biological markers. Methodological quality was evaluated using the modified Downs and Black checklist.
Results: Of the 1221 records identified, four cross-sectional studies (total: 199 participants; mean [SD]: 26.3 [6.4] years old) met the inclusion criteria. Three of the four included studies were conducted on participants who had undergone ACL reconstruction surgery. Two studies were of high methodological quality, one was of moderate quality and one was of low quality. The analysis showed that knee unloading (i.e., reduced knee adduction moment (KAM) and vertical ground reaction forces) was associated with an increase in cartilage MRI T1ρ and T2 relaxation times, suggesting a deterioration in cartilage composition. Reduced gait variability and kinematic alterations (reduced knee excursion, altered knee flexion angles and tibial rotations) correlated with early cartilage biochemical changes detectable through MRI T1ρ, T2 relaxation time. Meta-analysis was not feasible due to heterogeneity in outcomes among studies.
Conclusion: The included studies demonstrated significant associations between altered gait biomechanics and cartilage degradation. Biomechanical factors such as reduced KAM or reduced knee flexion angle during gait could serve as early indicators for OA risk and inform targeted rehabilitation interventions.
Level of evidence: Level III.
Keywords: gait; imaging; knee injury; knee surgery; osteoarthritis.
© 2025 The Author(s). Knee Surgery, Sports Traumatology, Arthroscopy published by John Wiley & Sons Ltd on behalf of European Society of Sports Traumatology, Knee Surgery and Arthroscopy.