Reverse Shoulder Arthroplasty in Patients With Amputation or Paralysis of the Contralateral Upper Extremity (One-Arm Patients)

Background: Theoretically, patients with only one functional arm secondary to contralateral amputation or paralysis will subject their only functional upper extremity to increased loads. This could become an issue after reverse shoulder arthroplasty (RSA). However, there are no reported data on the implant survival or function for patients with a nonfunctional contralateral upper extremity. Objective: To report the outcomes of RSA in patients with contralateral upper extremity amputation or paralysis. Design: Retrospective case series. Setting: Tertiary university hospital. Patients: All patients who underwent RSA between January 2004 and December 2013. Methods: Of 1335 RSA procedures performed, 5 patients had a minimum 2-year follow-up and nonfunctional contralateral upper extremity. There were 3 men and 2 women, with a mean (standard deviation) age and length of follow-up of 72.4 (7.5) years and 56.4 (24-132) months. Two of the patients had a contralateral upper extremity amputation, and the other 3 had contralateral upper extremity paralysis as a result of stroke, traumatic brain injury, and traumatic brachial plexus injury at birth. Main Outcomes: Pain, range of motion, functional scores (Simple Shoulder Test, American Shoulder and Elbow Society and Quick-Disability of the Arm, Shoulder and Hand), satisfaction, complications/reoperations, and radiographic loosening. Results: RSA resulted in substantial improvement in pain (P = .008), forward flexion (P = .02), and external range of motion (P = .01). The mean (standard deviation) Simple Shoulder Test, American Shoulder and Elbow Society, and Quick-Disability of the Arm, Shoulder, and Hand scores were 9.8 (1.3), 82 (13), and 17.8 (13.4), respectively. The results were excellent in 3, satisfactory in 1, and unsatisfactory in 1 patient (due only to external rotation limited to 10 degrees). Subjectively, all 5 patients felt greatly improved and stated they would undergo RSA again. There were no complications or reoperations. There were no shoulders with component loosening. Conclusions: RSA seems to be a safe, effective, and successful surgical procedure for patients with a nonfunctional contralateral upper extremity. Studies with larger sample sizes and longer follow-up will hopefully validate the present findings.