The focally constrained liner is a reasonable option for revision of unstable total hip arthroplasty.

Abstract

Revision surgery for a patient with previous recurrent dislocations or abductor muscle dysfunction has been considered to be a complication-prone procedure regardless of the type of constrained implant used. We investigated the survivorship of a focally constrained acetabular liner used for revision total hip arthroplasty in patients with abductor insufficiency or previous recurrent dislocations. We retrospectively reviewed 98 patients in whom a focally constrained acetabular liner was used to treat abductor insufficiency or previous recurrent dislocations. The mean age was 69.4years (37-92) and 64 of these were females. Previously, the patients had undergone a mean of two (1-5) revisions. The mean follow-up was 38 (12-66) months. Kaplan-Meier survival curves were calculated and Log-rank test was used to test the difference in survivorship between patients with abductor insufficiency and previous dislocations. Sixteen patients needed a further re-revision for any cause. Thus, the revision-free survivorship was 84.3% at five years. Five patients suffered a dislocation with a mean of fivemonths post-operatively and were managed with repeat revision. Five patients failed at the implant-host bone interface. Three of these failures occurred after cementing the constrained liner into a pre-existing shell. The focally constrained liner provided a reasonable option for revision total hip arthroplasty in patients with hip instability. Failures were observed in patients with acetabular osteolysis but seemingly well-fixed component and unrecognized impingement.