Treatment options for complex shoulder osteoarthritis with posterior humeral head subluxation and glenoid bone loss (Walch B): A systematic review.

Background: Shoulder osteoarthritis (OA) with eccentric (B) glenoids has generally been associated with poor patient-reported outcomes and increased complications. The purpose of this study was to outline all the described treatment options and their outcomes and complications in order to better guide treatment. Methods: This systematic review was performed according to the Preferred Reporting Items for Systematic review and Meta-analysis guidelines. Searches were performed up to December 19, 2019, using Medline, EMBASE, Scopus, and Cochrane databases. Inclusion criteria included studies for glenohumeral OA reporting posterior humeral head subluxation and/or posterior glenoid erosion. Studies were excluded if they were review papers, abstracts, or conference papers; had heterogeneity of included Walch types; or were not written in English. Results: Twenty-one studies met inclusion criteria. The mean follow-up duration was 47.5 months (range, 14-300), and the mean patient age 62 years (38-88). Six different discernible techniques were identified: asymmetric reaming with onlay glenoid (AROG) in 267 shoulders, posterior glenoid bone grafting (PGBG) with onlay glenoid in 79 shoulders, augmented glenoid (AG) in 160 shoulders, reverse shoulder arthroplasty (RSA) with or without bone grafting in 118 shoulders, hemiarthroplasty with concentric reaming (HACR) in 57 shoulders, and humeral head arthroplasty with inlay glenoid (HAIG) in 36 shoulders. All techniques reported improved patient outcomes and range of motion. Short-term (<5 years) studies reported glenoid loosening leading to revisions in 3% of AROG, 2.7% PGBG, 0.8% AG, 1.4% RSA, and 0% HAIG shoulders. HACR had a high revision rate (12.3%) due to persistent pain and stiffness. Midterm (>5 years) studies demonstrated increased rates of glenoid loosening with AROG (14.5%), PGBG (21% loose, 23.8% "at risk"), and AG (18.9% "at risk"), as well as increased rates of subluxation or revision due to instability. HAIG did not demonstrate loosening, subluxation, or revision at 55.2 months. Conclusion: Various techniques exist to manage complex primary glenohumeral OA with posterior subluxation and posterior glenoid erosion. Glenoid component survival is a concern with ASOG, PGBG, and AG. HACR has the highest early revision rate. RSA offers promising short-term and midterm results likely due to the advantage of more secure fixation as well as a constrained design to prevent posterior subluxation. HAIG has the lowest complication and revision rates although further long-term studies are needed.