Prognostic Value of Baseline Muscle Strength for Functional Recovery after Rotator Cuff Repair: An Observational Study.

Background: Although arthroscopic surgery restores tendon integrity and shoulder mechanics, the persistence of symptoms in some patients highlights the need to identify factors that influence rehabilitation outcomes. The aim of this study was to analyze the relationship between baseline muscle strength, assessed at the start of rehabilitation (6 weeks postoperatively), and clinical recovery at three and six months in patients undergoing arthroscopic rotator cuff repair.

Methods: From 2023 to 2024, a total of 76 participants undergoing arthroscopic rotator cuff repair were recruited consecutively and prospectively. Multivariable linear regression analysis was used to determine the association of each potential predictor (ipsilateral handgrip strength, contralateral handgrip strength, asymmetry of handgrip strength, and shoulder ipsilateral rotational strength) with functional outcomes at three and six months after surgery (Disabilities of the Arm, Shoulder, and Hand [DASH], Constant-Murley [CM] questionnaires, and Visual Analog Scale [VAS]), controlling for various covariates.

Results: 76 participants were included. Baseline handgrip strength in both the ipsilateral and contralateral limb was significantly associated with better functional outcomes at three and six months after surgery. Specifically at six months, greater contralateral handgrip strength was associated with better Constant-Murley scores (β: 0.36, 95% CI: 0.10 to 0.62; p=0.007), greater asymmetry in handgrip strength was significantly associated with worse Constant-Murley scores (β: -0.63, 95% CI: -1.13 to -0.13; p=0.014). Additionally, greater ipsilateral handgrip strength was significantly associated with lower pain scores (β: -0.28, 95% CI: -0.51 to -0.04; p=0.022). Interestingly, shoulder rotational strength was not associated with functional outcomes.

Conclusions: Early strength assessment was significantly associated with clinical recovery in patients undergoing rotator cuff repair. These findings highlight the potential clinical utility of bilateral handgrip strength assessments in guiding rehabilitation strategies after rotator cuff repair.