The role of subscapularis repair following reverse shoulder arthroplasty: systematic review and meta-analysis

Purpose Inadequate subscapularis repair has been advocated as one of the contributing factors for dislocation in reverse total shoulder arthroplasty; nonetheless the need to restore the subscapularis tendon integrity is under debate. The aim of this systematic review was to answer the question: does subscapularis reattachment following reverse total shoulder arthroplasty improve joint stability, range of motion and functional scores? Methods The literature was systematically screened in accordance with PRISMA guidelines looking for papers evaluating clinical outcomes of reverse total shoulder arthroplasty in relation to the management of subscapularis tendon. Studies comparing clinical outcomes, complications and dislocation rate with or without subscapularis repair were included. Studies in which reverse total shoulder arthroplasty was performed for trauma or tumors were excluded. The methodology of included articles was scored with MINORS scale and the Risk of Bias was assessed adopting the ROBINS-I (Risk Of Bias In Non-randomized Studies of Interventions) developed by the Cochrane Group. A meta-analysis was also performed combining the studies to increase the sample size and hence the power to obtain meaningful data. Results The database search identified 1062 records, and 6 full-text articles were finally included. A total number of 1085 reverse total shoulder arthroplasty were assessed on. Except for one study, lateralized prosthetic designs have been used. Dislocation occurred in 0.8% (5/599 patients) of the patient with repaired subscapularis and in 1.6% (8/486 patients) of the tenotomized patients, and subscapularis repair was not associated with a higher risk of dislocation (pooled Peto OR: 0.496, 95% CI: 0.163 to 1.510, p = 0.217). Qualitative assessment revealed no differences in the range of motion and clinical scores. Conclusion Subscapularis repair after reverse total shoulder arthroplasty produces no clinically meaningful benefits, particularly using lateralized prosthetic designs. Subscapularis re-attachment does not improve implant stability, nor increases range of motion or clinical scores. Given these results, keeping in mind the antagonistic effect of the repaired subscapularis on external rotation, no evidence lead to suggest subscapularis reattachment following reverse total shoulder arthroplasty with lateralized prosthetic designs.