The impact of different early rehabilitation initiation times on functional recovery after flexor tendon repair

This study aimed to evaluate the impact of varying rehabilitation initiation times on multidimensional functional outcomes following primary flexor tendon repair, aiming to define the optimal postoperative rehabilitation window. This single-center retrospective cohort study included 120 patients who underwent primary flexor tendon repair between June 2023 and June 2025. Patients were categorized into 3 groups based on the timing of their first postoperative rehabilitation session: group A (≤48 hours), group B (48–72 hours), and group C (72 hours–5 days). All patients received a standardized rehabilitation protocol. Primary outcomes included total active motion and Strickland grading. Secondary outcomes included tendon adhesion, rerupture rate, pain score (visual analogue scale), joint stiffness, grip-strength recovery ratio, improvement in activities of daily living, Vancouver Scar Scale score, and rehabilitation adherence. Baseline characteristics were comparable across the 3 groups ( P > .05). At 12 weeks, group A achieved significantly higher total active motion (185.3 ± 22.5°) than groups B (172.6 ± 25.1°) and C (160.8 ± 28.6°; P < .001). The proportion of patients with excellent-to-good Strickland outcomes was highest in group A (85.0%), followed by group B (72.5%) and group C (57.5%; P = .012). Tendon adhesion increased progressively with delayed rehabilitation initiation (A: 12.5%, B: 22.5%, C: 37.5%; P = .015). Rerupture rates did not differ significantly ( P = .350), indicating that early rehabilitation did not increase rupture risk. Group A experienced the lowest postoperative pain at all time points (all P < .001) and the lowest incidence of stiffness ( P = .046). Grip-strength recovery (at 6 and 12 weeks), activities of daily living improvement, and Vancouver Scar Scale scores were all significantly better in group A (all P < .001). Rehabilitation adherence was also highest in group A ( P = .020). Overall, initiation of rehabilitation within 48 hours yielded superior functional recovery, fewer complications, and better adherence compared with later initiation. For primary flexor tendon repair, ultra-early rehabilitation, defined as rehabilitation initiated within 48 hours postoperatively (≤48 hours) significantly improves digital mobility, reduces adhesion formation, alleviates pain, lowers the risk of stiffness, and enhances grip-strength recovery and functional independence, without increasing the risk of rerupture. Integrating these findings with existing evidence, rehabilitation initiation within 48 hours appears to be the most favorable postoperative rehabilitation window in this cohort.