Acute Effect of Rotator Cuff Repair on Shoulder Proprioception

Background Rotator Cuff Repair (RCR) is often used as a surgical intervention for rotator cuff tear. However, the acute effect of RCR on proprioception remain unclear. This study aimed to evaluate pre- and post-RCR shoulder abduction proprioception (SAP), using a purpose-built Active Movement Extent Discrimination Apparatus (AMEDA). Methods Thirty-two participants volunteered. SAP was assessed pre- and 72 hours post-operatively in 18 RCR patients (male: female = 6: 12, mean age = 58 yrs). Test-retest reliability was evaluated in 14 age-matched healthy volunteers with a 24-hour interval between tests. From the AMEDA test responses, proprioceptive acuity was quantified using the area under the ROC curve (AUC). The visual analogue scale for pain severity (VAS), Constant-Murley scale, and Fear Avoidance Beliefs Questionnaire (FABQ) were also administered. Results After RCR, SAP AUC improved significantly from 0.746 to 0.795 (ES = 0.61, p = 0.01). Postoperative SAP scores were significantly negatively associated with preoperative pain severity VAS (r = − 0.6, p <0.01), but not with postoperative pain, shoulder function, or fear avoidance beliefs. Importantly, preoperative pain severity VAS was the only independent predictor of post-operative SAP change (ΔSAP), demonstrating a strong negative relationship (β = − 0.54, p = 0.02). The AMEDA demonstrated good test-retest reliability (ICC _3,1 = 0.84, CV = 3.19%). Conclusion After RCR, SAP improved significantly, providing fundamental information for neuromuscular control rehabilitation. Preoperative pain severity was found to inversely predict proprioceptive change, highlighting the importance of pain management preoperatively for proprioceptive improvement after surgery. The AMEDA was shown to be reliable and valid instrument for assessing SAP.