Impact of prior anterior instability on shoulder arthroplasty outcomes: a systematic review

BACKGROUND: Anterior shoulder instability (ASI) is a frequently encountered pathology. Patients with a history of ASI have an increased rate of developing glenohumeral osteoarthritis and becoming candidates for shoulder arthroplasty. This systematic review aims to synthesize outcomes for patients undergoing shoulder arthroplasty with a history of ASI. METHODS: A comprehensive literature review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) using PubMed, Embase, OVID Medline, Scopus, CINAHL, Web of Science, and Cochrane databases for studies evaluating the impact of prior ASI on total shoulder arthroplasty (TSA), reverse TSA, and/or hemiarthroplasty outcomes, with a minimum follow-up of 12 months. Studies were graded by level of evidence and data concerning patient demographics and outcomes were extracted. RESULTS: Sixteen articles met the inclusion criteria, including 596 patients (413 male, 181 female). The average age of the control and prior ASI groups were 57.5 and 57.0 years, respectively. Overall, 251 patients were treated operatively, 132 nonoperatively, and 213 were controls without a history of prior ASI. Shoulder arthroplasty techniques included TSA (436 shoulders), reverse TSA (130 shoulders), and hemiarthroplasty (14 shoulders). Prior anterior stabilization management included soft tissue repair, bony augmentation, and nonoperative treatment. Almost all studies reported no significant difference in subjective and functional arthroplasty outcomes between control and prior ASI groups, or between patients with prior ASI treated nonoperatively vs. surgically. CONCLUSION: Shoulder arthroplasty in the setting of prior ASI results in improved subjective and functional outcome scores that are comparable to patients without a history of instability.