Instability After All-Cause Acetabular-Only Revision Total Hip Arthroplasty Remains a Clinical Problem.
Academic Article
Overview
abstract
BACKGROUND: The purpose of this study is to (1) evaluate the rate of instability and reoperation after acetabular component-only revision, (2) compare instability rates across various head sizes, and (3) determine patient factors correlating with postoperative instability. METHODS: We retrospectively reviewed all isolated acetabular component revisions (n = 200) at our institution between 2007 and 2017. Patients with less than one-year follow-up were excluded. Patients were subdivided into 4 head size groups: (1) 32 mm or less, (2) 36 mm or more, (3) dual mobility, and (4) constrained liners. Factors including the body mass index, cup position, prior revision(s), and subsequent reoperation were compared across groups. RESULTS: 189 patients (200 hips) met the inclusion criteria. The overall rate of instability was 12% (n = 24), and 37 (18.5%) cases underwent subsequent revision, including 11 cases for recurrent instability. There was no significant difference in postoperative dislocation or reoperation for instability across the various groups. The use of a constrained liner trended toward the highest rate of postoperative instability (36.4%, P = .090). History of preoperative instability was a significant risk factor for postoperative instability with or without history of prior revision (P = .011 and P = .001, respectively). CONCLUSION: Contemporary isolated acetabular revision is still associated with significant rates of instability. Surprisingly, the head size was not a predictive factor for postoperative dislocation or reoperation, but a prior history of instability was associated with postoperative instability. Patients revised to a constrained liner experienced highest rates of failure and remain an unsolved clinical problem.
