Acetabular augmentation ring for recurrent dislocations in revision arthroplasty.

We retrospectively reviewed 18 patients with recurrent dislocations after revision total hip arthroplasty with no identifiable specific cause. All patients were treated with an acetabular component augmentation ring to evaluate whether the acetabular augmentation ring effectively decreases the redislocation rate compared with other treatment options. The acetabular augmentation ring was implanted after an average of 4.9 dislocations and failed nonoperative or surgical treatment. Seven patients had postoperative complications, including four patients with persistent neurologic deficits. The average followup was 35.1 months (range, 24-52 months). During followup six patients experienced a dislocation. Four patients and three patients presented with implant loosening and deep infection, respectively. Overall, 10 patients had surgical revision and removal of the acetabular augmentation ring during followup. The remaining eight patients, who did not require additional surgical intervention, had an average Harris hip score of 42.5 (range, 9.5-61.7). The use of an acetabular augmentation ring is not supported by results of our study.