Midterm Outcomes After Arthroscopic Coracoid Decompression Combined With Manipulation for the Treatment of Frozen Shoulder Associated With Subcoracoid Impingement

Abstract

Background Patients with frozen shoulder (FS) suffer considerably, and some also present with subcoracoid impingement. However, effective treatments for frozen shoulder associated with subcoracoid impingement (FSASI) are limited. Primary purpose of this study was to introduce an arthroscopic coracoid decompression method combined with manipulation to treat FSASI and investigate its mid-term efficacy. Methods From April 2015 to May 2018, 177 patients with frozen shoulder who had no positive response to conservative therapy after a minimum of 6 months underwent arthroscopic coracoid decompression combined with manipulation. Shoulder condition was evaluated using the abbreviated Constant-Murley score (ACMS) and the modified University of California at Los Angeles Shoulder Rating Scale (MUCLA) preoperatively; at the 1st, 3rd, and 6th months postoperatively; and at the final follow-up (May 15, 2020). Results Eight patients were lost to follow-up, and 169 were included in the final analysis. The mean follow-up duration was 38.22 (range, 24–60) months. The ACMS improved from 16.39 ± 2.99 points (preoperative) to 72.08 ± 1.04 points at the last follow-up (p < 0.001). The MUCLA improved from 10.84 ± 0.71 points (preoperative) to 32.94 ± 0.74 points at the last follow-up (p < 0.001). Improvements in ACMS and MUCLA scores were significant in the first 3 months, then leveled off, and remained stable between the 6th month and the final follow-up. Recovery of forward flexion and abduction progressed synchronously, and almost full scores were achieved (9.96 ± 0.08 and 9.92 ± 0.11 points, respectively). Some patients lost ranges of motion: eight patients partially lost forward flexion and abduction, four partially lost external rotation, and fourteen partially lost internal rotation. The ACMS pain rating score improved from 1.12 ± 0.68 (preoperative) to 13.06 ± 0.71 points, and the MUCLA pain rating score improved from 1.67 ± 0.27 (preoperative) to 8.94 ± 0.43 points (last follow-up). Most improvements occurred in the first month after surgery. Timely pain improvement can effectively help patients improve sleep; complaints of sleep disturbance decreased significantly postoperatively. No complications or recurrence occurred. Conclusion Arthroscopic coracoid decompression combined with manipulation was an alternative method for treating FSASI, and satisfactory results were maintained through midterm follow-up.