Early results of reverse shoulder arthroplasty in patients with rheumatoid arthritis.

BACKGROUND

Rheumatoid arthritis affecting the shoulder is typically associated with rotator cuff compromise and can also result in severe glenoid erosion. Since reverse shoulder arthroplasty is capable of addressing both rotator cuff disorders and glenoid bone deficiencies, our aim was to evaluate the outcome of reverse shoulder arthroplasty in patients with rheumatoid arthritis and either or both of these associated conditions.

METHODS

We performed eighteen primary reverse total shoulder arthroplasties in sixteen patients with rheumatoid arthritis involving the shoulder as well as associated rotator cuff compromise and/or severe erosion of the glenoid bone between 2002 and 2007. Patients were assessed with use of the Constant score, patient satisfaction score, subjective shoulder value, range of shoulder motion, and imaging studies.

RESULTS

The mean Constant score improved from 22.5 to 64.9 points at a mean of 3.8 years (range, 2.1 to 7.0 years) postoperatively. The patients were either very satisfied or satisfied with the outcome of the surgery in seventeen of the eighteen shoulders. The mean subjective shoulder value was 68.6% postoperatively. Active forward elevation improved from 77.5° to 138.6°, and external rotation with the arm in 90° of abduction improved from 16.9° to 46.1°. The mean Constant score improved from 28.0 points to 74.3 points in shoulders in which the teres minor muscle was normal before the surgery, and it improved from 20.8 to 54.6 points in shoulders with an atrophic teres minor muscle. Scapular notching was observed in ten of the eighteen shoulders. A fracture involving the acromion, acromial spine, coracoid, or greater tuberosity was observed either intraoperatively or postoperatively in four of the eighteen shoulders. One case of transient axillary nerve injury was noted. There were no cases of dislocation, infection, or component loosening. None of the patients required revision surgery for any reason.

CONCLUSIONS

Comparatively good outcomes were observed in the short to intermediate term after reverse shoulder arthroplasty in patients with rheumatoid arthritis. However, surgeons should be aware of the risk of intraoperative and postoperative fractures in this patient group.