The Frequency of Glenohumeral Cartilage Lesions at the time of Shoulder Instability Surgery: A Multicenter Comparison of Primary and Revision Surgery Patients

OBJECTIVES: Revision shoulder stabilization procedures present a unique set of challenges that should be recognized by the treating surgeon in order to improve the likelihood of success. The current study aims to compare patient factors, intraoperative findings, and patient reported outcome measures between patients undergoing primary versus revision shoulder stabilization surgery. METHODS: The Multicenter Orthopaedic Outcomes Network (MOON) Shoulder Instability cohort was utilized to identify all patients undergoing primary and revision open or arthroscopic shoulder instability surgery. Patients with concomitant rotator cuff pathology requiring operative repair were excluded. Patient demographic characteristics, intraoperative findings, and patient reported outcome measures at the time of shoulder stabilization were compared between primary and revision shoulder instability surgery patients using univariate methods using chi-square or Fisher exact tests for categorical variables and Wilcoxon rank sum test for continuous variables. RESULTS: Primary shoulder stabilization procedures were performed in 625 (87.0%) patients and revision stabilization procedures in 93 patients (13.0%). Patients undergoing revision surgery were older (25.9 vs. 23.5 years, p<0.001), more frequently smoked (11.8 vs. 6.1%, p = 0.04), had a higher number of reported dislocation events (p = 0.004), and were more likely to undergo an open procedure as opposed to an all arthroscopic shoulder instability procedure (67.7 vs. 5.8%, p<0.001). Patients undergoing revision procedures were more likely to have glenoid or humeral head cartilage lesions at the time of surgery (77.4 vs. 57.8%, p<0.001), with bone loss involving greater than 20% of the glenoid or humeral head more frequently reported in revision procedures (19.4 vs. 2.6%, p <0.001) (Figure 1). However, the presence of glenohumeral bone loss did not negatively impact patient reported outcomes at the time of shoulder instability surgery. CONCLUSION: Glenohumeral articular cartilage lesions are a common finding at the time of shoulder stabilization procedures and are particularly frequent in patients undergoing revision stabilization procedures. Surgeons routinely performing these procedures should be prepared to deal with the technical challenges associated with glenoid or humeral head bone loss. However, at the time of surgery, the presence of articular cartilage lesions did not appear to negatively influence patient reported outcomes. Future studies should investigate the influence of articular cartilage lesions at mid- and long-term follow-up in this cohort of patients.