Bony increased offset reverse shoulder arthroplasty (BIO-RSA) vs metal augments: A systematic review

Lateralisation in reverse shoulder arthroplasty can be achieved through bone graft (BIO-RSA) or metal augments (MIO-RSA). This systematic review and meta-analysis aimed to compare outcomes in both these methods.

A systematic review of Pubmed, Cochrane, Medline and EMBASE was performed including all studies on primary reverse total shoulder replacements with lateralised glenoid components using either bone graft (BIO-RSA) or metal augments (MIO-RSA). Collected data for included studies included demographics, method of lateralisation and complications.

30 studies comprising 2364 shoulders in 2558 patients were included, with a mean age of 72.8 (23-93), and 59.7% being female. 1026 patients underwent BIO-RSA and 1328 underwent arthroplasty with metal augmented glenoid components. After 31.5 months (3-126) follow-up, there was a significantly lower pain score (p < 0.05) and higher ASES (p < 0.05) and UCLA (p < 0.05) scores in patients post MIO-RSA, but no significant difference in range of movement post-operatively. Moreover, there was lower rates of revisions (1.3% v 3.0%, p < 0.01), loosening (0.8% v 2.4%, p < 0.01) and scapular notching (3.8% v 17.3%, p < 0.01) in the MIO-RSA group.

BIO-RSA and MIO-RSA outcomes are summarised, suggesting preliminary evidence of some superiority of MIO-RSA, but heterogeneity in the selected studies limits the conclusions that can be drawn from results. Long term studies are required to ascertain if this effect is maintained.