Lateral acromioplasty cannot sufficiently reduce the critical shoulder angle if preoperatively measured over 40 degrees

摘要

Purpose To investigate whether arthroscopic lateral acromion resection can sufficiently reduce the critical shoulder angle (CSA) without damaging deltoid muscle insertion. Methods Ninety patients who underwent arthroscopic rotator cuff (RC) repair were retrospectively analysed. According to the preoperative CSA, patients were categorized as Group I (CSA = 35 degrees). Additional arthroscopic lateral acromion resection was performed in Group II. The CSA was measured 1 week postoperatively, while RC integrity and the deltoid attachment were assessed at 3, 6 and 12 months via ultrasound. Deltoid function was evaluated using the Akimbo test, in which patients place their hands on the iliac crest with abduction in the coronal plane and internal rotation of the shoulder joint while simultaneously flexing the elbow joint and pronating the forearm. Results Large and massive RC tears were more prevalent in Group II (p = 0.017). In both groups, the CSA reduction was statistically significant (Group I = 1 degrees: range 0 degrees-3 degrees, Group II = 3.7 degrees: range 1 degrees-8 degrees; p 40 degrees, the respective postoperative CSA remained > 35 degrees in 83.3% of cases (p 40 degrees.