Abstract
This systematic review aims to assess the contemporary literature on the incidence rate, functional scores, and clinical outcomes of heterotopic ossification (HO) following shoulder arthroplasty. We conducted a thorough literature search on EMBASE, MEDLINE, and Ortho Search to identify studies that directly compared patients with and without HO following hemiarthroplasty, anatomic total shoulder arthroplasty (aTSA), or reverse total shoulder arthroplasty (rTSA). We included studies with a minimum follow-up period of one year published from January 2000 to March 2023. We excluded case reports, editorials, and reviews. We performed the systematic review in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Of the 297 studies initially identified, seven met our inclusion criteria. These studies evaluated a total of 1,134 arthroplasties (212 hemiarthroplasties, 376 aTSAs, and 546 rTSAs). The mean follow-up period was 30.52 (12-120) months and the mean age was 68.69 (20-92). The overall incidence rate of HO was 26.8% (304/1,134). Male gender was associated with a higher incidence rate of HO in three studies. No statistically significant difference was noted in symptoms at follow-up or in Constant-Murley score at two years of follow-up (HO vs. non-HO: 70 vs. 75, p = 0.081). Only one study reported a significant difference in the post-arthroplasty range of motion, specifically in forward elevation (121° vs. 133°, p = 0.0087) and external rotation (19° vs. 25°, p-value = 0.0266). We conclude that HO after shoulder arthroplasty does not display a significant impact on postoperative symptoms or functional outcomes in the majority of patients. To fully comprehend its effect, further research and consensus among experts is necessary.