Revision Reverse Shoulder Arthroplasty for Anatomical Glenoid Component Loosening Was Not Universally Successful: A Detailed Analysis of 127 Consecutive Shoulders.

BACKGROUND

Glenoid component loosening is a primary cause of failure of anatomical total shoulder arthroplasty (TSA) and is commonly associated with glenoid bone loss. The purpose of the present study was to evaluate the outcome and survival following revision to a reverse total shoulder arthroplasty (RSA) for the treatment of loosening of a polyethylene cemented glenoid component in the setting of failed TSA.

METHODS

Between 2010 and 2017, 151 shoulders underwent revision to RSA for the treatment of loosening of an anatomical polyethylene glenoid component. Shoulders with staged reconstruction for the treatment of infection were excluded. One hundred and twenty-seven patients (67 women and 60 men) had a single-stage reconstruction and were available for follow-up. The mean age at the time of surgery was 70 years (range, 41 to 93 years). In all cases, the humeral component was revised and a standard glenoid baseplate was utilized. Bone graft was used at the discretion of the treating surgeon. Medical records and radiographs were reviewed to collect demographic, intraoperative, and postoperative data; to quantify glenoid bone loss; and to determine the radiographic outcome. The mean duration of follow-up was 35 months (range, 24 to 84 months).

RESULTS

Revision to RSA resulted in significant improvements in terms of pain and motion. Sixteen shoulders (13%) underwent revision surgery for the treatment of baseplate loosening. Radiographic baseplate loosening was present in 6 additional shoulders (overall rate of baseplate loosening, 17%). Intraoperative fracture or fragmentation of the greater tuberosity occurred in 30 shoulders (24%). Other reoperations included resection for deep infection (3 shoulders), arthroscopic biopsies for unexplained persistent pain (2 shoulders), humeral tray exchange for dislocation (2 shoulders), revision for humeral loosening (1 shoulder), irrigation and debridement for hematoma (1 shoulder), and internal fixation of periprosthetic fracture (1 shoulder) (overall reoperation rate, 20%). Among shoulders with surviving implants at the time of the most recent follow-up, pain was rated as none or mild in 83 shoulders (65.4%) and the average active elevation and external rotation were 132° and 38°, respectively. With the numbers available, no risk factors for failure could be identified.

CONCLUSIONS

Revision RSA for the treatment of loosening of an anatomical polyethylene component was associated with a 17% glenoid mechanical failure rate. Although this procedure resulted in improvements in terms of pain and function, it was not universally successful and thus needs further refinement in order to improve outcomes.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.