Standard versus bony increased-offset reverse shoulder arthroplasty: a retrospective comparative cohort study

Abstract

Background: To date, only a few comparative studies with small sample sizes have compared a traditional reverse shoulder arthroplasty (tRSA) to a bony increased-offset RSA (BIO-RSA). We hypothesized that the BIO-RSA would lead to lower notching rates and improved range of motion (ROM) compared with a tRSA.

Methods: A retrospective review was performed of 69 tRSAs and 61 BIO-RSAs performed by a single surgeon. At 2 years postoperative, ROM and Constant scores were compared. Radiographs were examined for scapular notching, scapular spurring or ossification, and graft healing.

Results: At the 2-year follow-up, the BIO-RSA group demonstrated improved anterior forward flexion compared with the tRSA group (145° ± 20° vs. 138° ± 20°, respectively; P = .017). There was no difference in external or internal rotation between the 2 groups. The BIO-RSA group had a higher Constant score than the tRSA group (69 ± 9 vs. 61 ± 13; P < .001). The radiographs showed no difference between the 2 groups, including scapular notching (P = .150).

Conclusion: At the 2-year follow-up, BIO-RSA does not lead to a clinically significantly improvement in ROM, Constant scores, or change in scapular notching compared with a tRSA.

Keywords: BIO-RSA; Shoulder prosthesis; bony increased-offset; glenoid and humeral lateralization; postoperative function; range of motion (ROM); reverse shoulder arthroplasty.