Does correction of reverse shoulder arthroplasty angle improve clinical outcomes in cuff tear arthropathy?

The aim of this study was to investigate the impact of correction of the reverse shoulder arthroplasty (RSA) angle on clinical outcomes in patients with cuff tear arthropathy (CTA).

This single-center retrospective study was conducted in patients with CTA treated with RSA between 2013 and 2018. A structured questionnaire collecting demographic data, postoperative follow-up time, pre- and postoperative range of motion (ROM), American Shoulder and Elbow Surgeons (ASES) and Constant functional scores as well as scapular notching according to the Sirveaux Classification and RSA angle were evaluated by independent observers. The association between functional outcomes and RSA angle was analyzed using a curve estimation approach.

Seventy-four patients with a mean age of 69.4 ± 8 years and mean follow-up period of 38.2 ± 10.8 months were included the study. The medialized inlay component was implanted in 35 patients, and the lateralized onlay component was used in 39 patients. The mean preoperative ASES and Constant scores improved from 28.4 ± 5.1 and 31.1 ± 5.9 to 73.4 ± 23.3 and 70.5 ± 16, respectively, at the last follow-up (both P < 0.001). The mean pre- and postoperative RSA angles were measured to be 21.3 ± 9.3° and 5.5 ± 10.1°, respectively, on X-ray. The postoperative RSA angle was 10.4 ± 10.3° in computerized tomography (CT) scans. There was an excellent correlation between X-ray and CT measurements (rs: 0.971, P < 0.001). It was found that patients with good postoperative functional scores tended to have an RSA angle of 0-10° postoperatively. The delta internal rotation of the medialized design group was greater than that of the lateralized design group (P = 0.029).

In patients undergoing RSA for CTA, satisfactory clinical outcomes can be obtained by achieving a postoperative RSA angle of 0-10° with an asymmetrical inferior reaming technique.

Level III, Therapeutic Study.