Abstract
Introduction
Previous reports have investigated the correlation between time to revision hip arthroplasty (rTHA) and reason for revision, but little is known regarding the impact of timing on outcomes following rTHA. The purpose of this study is to evaluate the effect of time to rTHA on both indication and outcomes of rTHA.
Methods
This retrospective observational study reviewed patients who underwent unilateral, aseptic rTHA at an academic orthopedic specialty hospital between January 2016 and April 2019 with at least 1-year of follow-up. Patients were early revisions if they were revised within 2 years of primary THA (pTHA) or late revisions if revised after greater than 2 years. Patient demographics, surgical factors, and post-operative outcomes were compared between the groups. Post-hoc power analysis was performed (1-β=0.991).
Results
188 cases were identified, with 61 hips undergoing early revision and 127 undergoing late revision. There were no differences in demographics and comorbidities between the groups. Type of revision differed between the groups, with early revisions having a greater proportion of femoral revisions (54.1% vs.20.5%) and late revisions having a greater proportion of both component (10.2% vs.6.6%), acetabular (30.7% vs.26.2%), or head/liner (38.6% vs. 13.1%;p< 0.001) revisions. Indication for index revision differed between the groups, with early revisions having a greater proportion for dislocation/instability (21.3% vs. 10.2%) and peri-prosthetic fracture (42.6% vs.9.4%), and late revisions having a greater proportion for loosening/osteolysis (40.9% vs.24.6%), metal-on-metal complications (11.0% vs.0.0%), and liner wear (18.9% vs.0.0%;p< 0.001). Early revisions experienced longer length of stay (LOS; 5.18±4.43 vs.3.43±2.76 days;p=0.005) and more often underwent reoperation (8.2% vs 1.6%;p=0.037).
Conclusions
Early aseptic revisions had worse outcomes with longer LOS and higher rates of reoperation. These differences may be attributable to the type and indication for revision. Arthroplasty surgeons should be aware of these differences when counseling patients after THA.
