The role of the subscapularis tendon in a lateralized reverse total shoulder arthroplasty: repair versus nonrepair

Purpose The reverse shoulder prost hesis (rTSA) is now implanted by the same percentage of anatomic shoulder prosthesis in the USA. Scapular notching and loss of extrarotation have been underlined as complication at long-term follow-up due to the Grammont design. The current trend to reduce those limits is to position both components lateralized. As the role of the subscapularis tendon in this new rTSA design is unclear, the purpose of this study is to quantify rTSA outcomes in patients with or without subscapularis tendon suture. Methods The surgery was performed by the same orthopaedic surgeon (F.F.), using a Aequalis Ascend (TM) Flex prosthesis (Tornier, Montbonnot, France) with a bone autograft. Forty-four patients underwent surgery with the tendon sutured, whereas 40 patients underwent the same surgery without repairing it. Patients were evaluated pre-operatively and at the last follow-up using Constant score, VAS, and ROM. The minimum and mean follow-ups were six and 16.6 months, respectively. Results All patients showed statistically significant improvement in pain and joint function following surgery. This study highlighted significant higher values in intrarotation and abduction, respectively, with and without suturing the subscapularis tendon. However, no significant differences were underlined in Constant score, VAS, forward flexion, extrarotation at 0 degrees and 90 degrees of abduction, and rate of instability. Conclusions As predicted, significant clinical improvements were observed in both groups with some differences. These clinical results showed that the use of rTSA with lateralized humerus and bony increase offset leads to realistic clinical improvements with a low risk of instability without the need for compression and stabilization of the tendon.