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

BackgroundFrozen 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 360o release may be performed. The aim of this study is to evaluate the clinical outcomes following the FS 360o arthroscopic release.MethodsAn observational prospective cohort study was conducted assessing patient-reported outcome measures (PROMs) in patients who underwent the 360o 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 (OSS), Western Ontario Shoulder Index (WOSI), Disabilities of the Arm, Shoulder and Hand (QuickDASH), Constant-Murley Score (CMS), American Shoulder and Elbow Surgeons shoulder score (ASES), as well as general measures of pain intensity (VAS) and wellbeing (EQ-5D-3L). AROM movements included forward flexion, abduction, external rotation, internal rotation, as well as external and internal rotation at 90° of abduction.Results50 consented patients underwent the arthroscopic FS 360° release. The mean age was 52.1+7.7 years (range 35-72), and mean BMI was 27.1+4.7kg/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<0.001). 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>0.05). No complications or reoperations were reported.ConclusionThe arthroscopic 360o release is an effective and safe treatment modality for severe or recalcitrant FS. Statistically and clinically significant improvements in AROM and PROMs (OSS, WOSI, Quick-DASH, CMS, ASES) 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 non-pathological contralateral shoulder at 24 months.