Step It Up to Level Up: After Anterior Cruciate Ligament Reconstruction, Do Individuals Reach Internationally Recommended Physical Activity Levels and How Do These Levels Compare With Uninjured Controls? A Systematic Review and Meta-Analysis.

Anterior cruciate ligament reconstruction (ACLR) leads to high rates of knee post-traumatic osteoarthritis (PTOA). Physical activity may mitigate PTOA risk but levels after ACLR have not been extensively studied. We aimed to review self-reported and device-measured physical activity levels in individuals with ACLR and compare them with international guidelines, and with uninjured controls. MEDLINE, Embase, Scopus, Google Scholar, Cochrane Library, Web of Science, and SPORTDiscus were searched from inception to 22 June 2023. Of the 5391 studies identified on our initial search, 15 satisfied the inclusion criteria for analysis (N = 544 individuals with ACLR). Across all studies, the average physical activity levels for individuals with ACLR were 343 ± 185 moderate-to-vigorous physical activity (MVPA) min/wk and 8453 ± 233 steps/day. In studies measuring the proportion of individuals with ACLR reaching MVPA guidelines, 147/213 (69%) achieved ≥150 min/wk. Of those using step counts, 22/85 (26%) achieved ≥10 000 steps/day. Individuals with ACLR engaged in less physical activity than uninjured controls (SMD = -0.37 [95% CI = -0.60 to -0.15]; P < 0.001). Individuals typically meet recommended MVPA, but not steps, after ACLR. Optimal volume, type, and weight-bearing nature of physical activity should be further investigated given the beneficial role of moderate mechanical loading in knee health. Our findings suggest that steps per day may represent a potentially modifiable prevention target and may help guide the future development of tailored physical activity guidelines for PTOA prevention after ACLR. CRD42022330699.