The clinical course and outcomes following arthroscopic frozen shoulder 360° release

Background

Frozen shoulder (FS) is a debilitating inflammatory condition affecting the shoulder capsule that causes significant pain and stiffness. Its etiology, pathophysiology, and treatment remain poorly understood. Although regarded as self-limiting, FS can have profound implications on the activities of daily living and usually takes 1-4 years to resolve on its own accord. In recalcitrant or severe cases where active range of motion (AROM) is extensively restricted, an arthroscopic 360° release may be performed. The aim of this study is to evaluate the clinical outcomes following the FS 360° arthroscopic release.

Methods

An observational prospective cohort study was conducted assessing patient-reported outcome measures (PROMs) in patients who underwent the 360° arthroscopic release between July 2013 and January 2019. Various questionnaires were used to evaluate their shoulder preoperatively and at 2 weeks, 6 weeks, 3 months, 6 months, 12 months, and 24 months postoperatively. Relevant PROMs included the Oxford Shoulder Score; Western Ontario Shoulder Instability Index; Disabilities of the Arm, Shoulder, and Hand; Constant-Murley Score; American Shoulder and Elbow Surgeons score; and general measures of pain intensity (visual analog scale) and well-being (EQ-5D-3L). AROM movements included forward flexion, abduction, external rotation, internal rotation, as well as external and internal rotation at 90° of abduction.

Results

Fifty consented patients underwent the arthroscopic FS 360° release. The mean age was 52.1 ± 7.7 years (range 35-72), and mean body mass index was 27.1 ± 4.7 kg/m² (range 19.5-37.5). All PROMs, AROM movements, patient satisfaction, and EQ-5D-3L scores improved significantly between preoperative and 24-month time points (P < .001). Within-participant analysis demonstrated that there was no significant difference between the pathological shoulder AROM and the contralateral (healthy) shoulder AROM (collected preoperatively) for any movement at 24 months postoperatively (all P > .05). No complications or reoperations were reported.

Conclusion

The arthroscopic 360° release is an effective and safe treatment modality for severe or recalcitrant FS. Statistically and clinically significant improvements in AROM and PROMs (Oxford Shoulder Score; Western Ontario Shoulder Instability Index; Disabilities of the Arm, Shoulder, and Hand; Constant-Murley Score; and American Shoulder and Elbow Surgeons score) occurred shortly after the surgery and progressively improved from 2 weeks to 24 months postoperatively, with the operative shoulder achieving similar range of motion as the nonpathological contralateral shoulder at 24 months.