Sub-Acromioclavicular Decompression Increases the Risk of Postoperative Shoulder Stiffness after Arthroscopic Rotator Cuff Repair

Objective: The sub-acromioclavicular (SAC) decompression is often performed during arthroscopic rotator cuff repair. However, the impact of SAC decompression on patients with postoperative shoulder stiffness (POSS) are controversial and unclear. This study is aim to evaluate the impact of additional sub-acromioclavicular (SAC) decompression during arthroscopic rotator cuff repair on the postoperative shoulder stiffness (POSS) in patients. Methods: This retrospective study examined digital data from patients with full-thickness rotator cuff tears who underwent arthroscopic rotator cuff repair at a local institution. Patient-reported outcomes were evaluated using the American Shoulder and Elbow Surgeons (ASES) Score, the University of California-Los Angeles (UCLA) score, and visual analog scale (VAS) scores. Restricted shoulder mobility occurring within 6 months postoperatively, lasting more than 12 weeks, characterized by a passive forward flexion angle of <120 degrees or an external rotation angle of <30 degrees, with or without associated shoulder pain was identified as POSS. Factors affecting POSS were analyzed by binary logistic regression analysis. The patient-reported outcomes scores were analyzed by generalized estimating equations to examine the impact of SAC decompression. Results: A total of 155 patients met the set criteria and were included in the study. The analysis of binary logistic regression showed that diabetes (p = 0.001) and SAC decompression (p = 0.003) were independent factors for POSS. In the analysis of each follow-up point, only at the 3-month follow-up, the ASES scores (p = 0.003), UCLA scores (p = 0.045), and VAS scores (p = 0.005) showed significant differences between the SAC decompression group and the non-decompression group. For the intergroup comparison, the results showed a significant difference in the ASES scores (beta = -4.971, p = 0.008), UCLA scores (beta = -1.524, p = 0.019), and VAS scores (beta = 0.654, p = 0.010) throughout the study duration between the SAC decompression group and the non-decompression group. Conclusion: The findings of this study suggested that SAC decompression during arthroscopic rotator cuff repair increase the risk of POSS compared with those without the decompression, which indicate surgeons do not perform SAC decompression unless necessary.