Background: Revision total hip arthroplasty with modular component exchange can limit morbidity by retaining well-fixed components but dislocation has been a relatively frequent postoperative complication. This study evaluated the effect of surgical approach on dislocation rate in a modern revision cohort.
Methods: From 2010 to 2020, 248 aseptic head and liner exchanges were performed at a single institution. The mean patient age at revision was 64.9 ± 10.4 years and 50% (123/248) were performed among males. Indications for revision included 140 (56%) for polyethylene wear, 68 (27%) for failed metal-on-metal components, and 40 (16%) for instability. The mean follow-up after revision was 2.3 years.
Results: Thirty (12%) hips dislocated at a mean of 0.6 years (range 0.01-4.6) postoperatively. The dislocation rate by revision approach was 17% (9/54) for the direct anterior, 6% (5/80) for the direct lateral, and 14% (16/114) for the posterolateral approach (P = .13). Hips revised by the direct anterior approach that dislocated were more abducted (51 ± 8 vs 45 ± 8, P = .05) and more anteverted (26 ± 9 vs 20 ± 7, P = .04) than non-dislocators. Among all 248 hips, cups with more than 48° of abduction were 2.6 times more likely to dislocate (P = .01). Head diameter, neck length, patient age, and gender were not associated with dislocation (P ≥ .20).
Conclusion: Dislocation remains a common complication after head and liner exchange regardless of approach. Cup position is associated with postoperative instability and must be critically evaluated during preoperative planning.
Keywords: acetabular liner; dislocation; femoral head; revision total hip arthroplasty; surgical approach.
Copyright © 2021 Elsevier Inc. All rights reserved.