Time to Revision Total Hip Arthroplasty Impacts Short-Term Outcomes Following Surgery

Abstract

Previous reports have investigated the correlation between time to revision total 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 outcomes following rTHA. This retrospective observational study reviewed patients who underwent unilateral, aseptic rTHA at an academic orthopaedic hospital between June 2011 and April 2020 with at least 1-year of follow-up. Patients were categorized as early revisions if revised within 2 years of primary total hip arthroplasty (pTHA) or late revisions if revised after more than 2 years from pTHA. Patient demographics, surgical factors, and postoperative outcomes were compared. Multiple linear regression and binary logistic regression were used to determine significance of outcomes while controlling for confounding variables. Of the 467 cases, 150 underwent early revision and 317 underwent late revision. Early revisions experienced longer hospital length of stays (LOSs, days; 4.93 ± 3.93 vs. 3.28 ± 2.09; p < 0.001), all-cause 90-day readmission rates (11.3 vs. 12.7%; p = 0.032). Across all revision types, multivariate analysis revealed that time to rTHA (p < 0.001) and revision type (0.008) were found to be significant predictors of LOS while controlling for patient factors. Subanalyses within each revision type (femoral, acetabular, head/liner, and full) further reveal that time to rTHA is a significant independent predictor of LOS. Early revisions had a greater proportion of femoral revisions (44.0 vs. 15.5%), and late revisions had a greater proportion of head/liner (43.2 vs. 18.7%; p < 0.001) revisions. There were no significant differences between the two cohorts with respect to discharge disposition, surgical time, all-cause 90-day emergency department (ED) visits, re-revisions, and number of re-revisions. Patients undergoing aseptic rTHA within 2 years of index pTHA had longer LOS and greater rates of readmission. Time to rTHA is a significant independent predictor of LOS across and within all revision types and reason for revision aside from liner exchange and trunnionosis. No differences were seen in operative time, discharge disposition, re-revision, mortality, reoperation, and ED admission between early and late rTHAs across all revision subtypes. Level of evidence is III, retrospective observational analysis.