Salvaging unstable or recurrent dislocating total hip arthroplasty with the constrained acetabular component.

PURPOSE To review cases of implantation of constraining acetabular components for unstable or recurrent dislocating total hip arthroplasty at the Department of Orthopaedics, Concord Hospital, Sydney. METHODS A retrospective analysis was performed on prospectively collected data of 13 consecutively enrolled patients. RESULTS From 1989 to 2000, 13 constraining acetabular components were implanted into 13 patients as a revision procedure. The surgical approach for the implantation of the constrained liner was posterolateral in 11 cases; a modified Hardinge approach was applied in 2 cases. The mean clinical follow-up duration was 43 months (range, 14-121 months) and the mean age at the time of surgery was 73 years (range, 52-84 years). No patients were lost to follow-up. Indications for using the constrained acetabular component were recurrent dislocation in revision hip replacements (n=8), and intra-operative instability (n=5). There were no episodes of dislocation of the constrained arthroplasty. In 7 cases, the constrained component was implanted into a previously well-fixed shell. CONCLUSION We recommend the judicious use of the constrained component in cases of hip instability during or after total hip arthroplasty when other methods are not successful.