Heterogeneity in Complication Risks and Temporal Trends Across Aseptic Indications for Revision Total Hip Arthroplasty.

Abstract

With the increasing burden of revision total hip arthroplasty (rTHA), the comparative postoperative risk profiles among aseptic rTHA indications remain incompletely understood. This study evaluated postoperative periprosthetic joint infection (PJI), reoperation, and re-revision following rTHA for periprosthetic fracture (PPFx), dislocation, and mechanical failure. Secondarily, medical complications and temporal trends were assessed. Using an insurance claims database, first-time rTHA patients were identified using side-specific diagnosis coding and stratified by aseptic indication for rTHA. Groups were propensity-matched on demographics and comorbidities. Outcomes were assessed up to five years using Chi-square testing, Kaplan-Meier analyses, Cox regressions, and analyses of variance. Temporal trends were evaluated annually from 2016 to 2022. Among 3,876 matched patients, PJI incidence differed across groups from 90 days (periprosthetic fracture: 7%; dislocation: 6%; mechanical failure: 4%; P = 0.005) through five years (11, 10, 7%; P = 0.015). The five-year re-revision (PPFx: 8%, dislocation: 13%, mechanical failure: 10%; P < 0.001) and reoperation (10, 15, 11%; P = 0.002) rates were highest for dislocation. Cox regressions identified increased PJI risk for PPFx (hazard ratio (HR): 1.43) and dislocation (HR: 1.35). Dislocation demonstrated increased re-revision (HR: 1.28) and reoperation (HR: 1.26) risks. Revisions for PPFx demonstrated higher 90-day transfusion and readmission rates and longer hospital stays (P < 0.05). From 2016 to 2022, rTHA for PPFx increased by 282% and dislocation by 8.7%. Re-revision-free survival improved for PPFx (from 89.5% in 2016 to 94.2% in 2022) and dislocation (83.2 to 86.9%). The PJI-free survival showed no improvement across indications from 2016 to 2022. While rTHA for PPFx may represent an infection-prone and resource-intensive revision scenario, revision for dislocation carried the highest risk of re-revision and reoperation. Although rising rTHAs for PPFx warrant attention, instability remains a challenging revision indication, underscoring the importance of indication-specific risk stratification.