Hop testing is widely used by clinicians to monitor rehabilitation and decide when to return to sport following anterior cruciate ligament reconstruction (ACLR); however, the trajectory of long-term hop performance has not been summarised. To investigate hop performance change over time after ACLR. Systematic review with longitudinal meta-analysis. MEDLINE, EMBASE, CINAHL, Scopus, Cochrane CENTRAL and SPORTDiscus to 28 February 2023. Studies with ≥ 50 participants following primary ACLR, with mean participant age of 18-40years, reporting a quantitative measure of hop performance (e.g. single forward hop distance). Results had to be reported for the ACLR limb and compared with (1) the contralateral limb (within person) and/or (2) an uninjured control limb (between person). We included 136 studies of 23,360 participants. Performance was similar across different hop tests, with steep initial improvements in within-person symmetry, tailing off after 18-24months. ACLR limb hop performance was 5-10% lower compared with the contralateral limb at 1year post-surgery, with largest deficits observed for vertical hop [87.0% contralateral limb (95% CI 85.3-88.8) compared with single forward hop 93.8% (95% CI 92.8-94.9)]. By 3-5years, results were similar between ACLR and contralateral limbs. There were limited data for between-person comparisons (n = 17 studies). Exploratory analyses showed deficits in all forward hopping tests to be very strongly correlated with each other [e.g. single forward and triple hop rho = 0.96 (95% CI 0.90-0.99)], though there was discordance in the relationship between single forward hop and vertical hop performance [rho = 0.27 (95% CI - 0.53 to 0.79)]. Hop performance is comparable to the uninjured limb by 3-5years post-ACLR, with the greatest deficits in within-person symmetry present in vertical and side hop tests. Assessment of hopping in multiple planes and comparison with uninjured controls, may provide the most complete evaluation of functional performance.
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