ABSTRACT
BACKGROUND: There is limited knowledge regarding revision of reverse shoulder arthroplasty (RSA). This study assesses reasons for failure in RSA and evaluates the outcomes of revision RSA. MATERIALS AND METHODS: Between 1997 and 2009, 37 patients with RSA had revision surgery. Clinical and radiologic examinations performed preoperatively and at 3 months, at 6 months, and then annually postoperatively were analyzed retrospectively. Patients were reviewed with a minimum 2-year follow-up. RESULTS: The most common causes for RSA revision were prosthetic instability (48%); humeral loosening, derotation, or fracture (21%); and infection (19%). Only 2 patients (3%) had to be reoperated on for glenoid loosening. More than 1 re-intervention was performed in 11 patients (30%) because of recurrence of the same complication or appearance of a new complication. Underestimation of humeral shortening and excessive medialization were common causes of recurrent prosthetic instability. Proximal humeral bone loss was found to be a cause for humeral loosening or derotation. Previous surgery was found as a potential cause of low-grade infection. At a mean follow-up of 34 months, 32 patients (86%) had retained the RSA whereas 2 patients (6%) had undergone conversion to humeral hemiarthroplasty and 3 (8%) to a resection arthroplasty. The mean Constant score in patients who retained the RSA increased from 19 points before revision to 47 points at last follow-up (P < .001). CONCLUSIONS: Even if revision may lead to several procedures in the same patient, preservation or replacement of the RSA is largely possible, allowing for a functional shoulder. Full-length scaled radiographs of both humeri are recommended to properly assess humeral shortening and excessive medialization before revision.
