Can a functional difference be detected in reverse arthroplasty with 135° versus 155° prosthesis for the treatment of rotator cuff arthropathy: a prospective randomized study

J Shoulder Elbow Surg. 2019 May;28(5):813-818. doi: 10.1016/j.jse.2018.11.064. Epub 2019 Feb 15.


Background: The purpose of this randomized controlled trial was to compare humeral inclinations of 135° and 155° in patients undergoing primary reverse shoulder arthroplasty (RSA). Our hypothesis was that forward flexion would be higher in the 155° group but be associated with a higher rate of scapular notching.

Methods: A randomized controlled trial was conducted on 100 primary RSAs performed with a humeral inclination of either 135° or 155°. The prostheses were otherwise identical and a neutral glenosphere was used in all cases. Functional outcome, forward flexion, external rotation, and scapular notching were assessed at a minimum of 2 years postoperatively.

Results: There was no difference in range of motion or functional outcome scores between the 2 groups. In the 155° group, forward flexion improved from 76° to 135° (P < .001) and external rotation remained unchanged (29° vs. 30°; P = .835). In the 135° group, postoperative forward flexion improved from 78° to 132° (P < .001) and external rotation was unchanged (28° vs. 29°; P = .814). Scapular notching was observed in 58% of cases with a 155° inclination compared with 21% with a 135° inclination (P = .009).

Conclusion: With a neutral glenosphere there was no difference in postoperative forward flexion or external rotation after an RSA with a humeral inclination of 135° compared with 155°. Scapular notching was reduced with the use of 135° design compared with a 155° design but persists at a rate of 21% at 2-year follow-up in the absence of a lateralized glenosphere.

Keywords: 135°; 155°; Reverse shoulder arthroplasty; forward flexion; humeral inclination; randomized controlled trial; scapular notching.

Publication types

  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Arthroplasty, Replacement, Shoulder / adverse effects
  • Arthroplasty, Replacement, Shoulder / methods*
  • Female
  • Humans
  • Humerus / surgery
  • Male
  • Middle Aged
  • Prospective Studies
  • Range of Motion, Articular
  • Rotation
  • Rotator Cuff / surgery
  • Rotator Cuff Injuries / surgery*
  • Shoulder Prosthesis / adverse effects