Abstract
Objective
To investigate the association between rehabilitation initiation timing and shoulder stiffness and functional recovery after arthroscopic rotator cuff repair (ARCR).Methods
Patients who underwent ARCR between January 2019 and January 2023 were retrospectively identified. Based on documented rehabilitation initiation time, patients were classified post hoc into early (n = 64) or delayed rehabilitation groups (n = 71). The primary outcome was shoulder stiffness at 3 months. Secondary outcomes included Constant and American Shoulder and Elbow Surgeons (ASES) scores, visual analog scale (VAS) pain scores, and passive forward flexion. Inverse probability of treatment weighting (IPTW) was used for sensitivity analysis. Subgroup analyses assessed whether the observed association varied by patient characteristics.Results
Among 135 patients, early rehabilitation was associated with less shoulder stiffness at 3 months and more favorable outcomes during follow-up, including higher Constant and ASES scores, lower VAS pain scores, and greater passive forward flexion. Linear mixed-effects models demonstrated significant improvements over time in all outcomes, although the overall group-by-time interactions were not statistically significant. The estimated between-group difference in passive forward flexion was greatest at 3 months. IPTW analysis generally supported the primary findings.Conclusion
Early rehabilitation was associated with less shoulder stiffness and earlier recovery of shoulder function and passive forward flexion after ARCR. These observational findings do not establish causality. Randomized trials with systematic monitoring of repair integrity and adverse events are needed to determine the effectiveness and safety of early rehabilitation.