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.
Keywords
total hip arthroplasty - revision total hip arthroplasty - timing - outcomes
