Eligibility for One-Stage Exchange Arthroplasty for Hip Periprosthetic Joint Infection Predicts Survivorship: A Retrospective Review of 368 Cases.

BACKGROUND

A two-stage exchange arthroplasty is the standard treatment for chronic periprosthetic joint infection (PJI) of total hip arthroplasty (THA), though one-stage exchange arthroplasty is gaining interest. The proportion of THA PJIs eligible for one-stage exchange arthroplasty remains unclear. We aimed to determine what proportion of patients undergoing two-stage exchange arthroplasty for THA PJI met one-stage criteria and how eligibility impacted outcomes.

METHODS

Between 2000 and 2020, there were 368 two-stage exchange arthroplasties for THA PJI at our institution. The mean age was 65 years, the mean body mass index (BMI) was 32, and 60% were men. The one-stage exchange arthroplasty eligibility criteria included unilateral PJI with preoperatively identified susceptible, nonfungal, and non-multi-resistant bacteria; McPherson A host status; no prior two-stage exchange arthroplasty; minimal bone or soft-tissue loss; and absence of sepsis. Cumulative incidences of reoperation for infection, re-revision for infection, any reoperation, and any re-revision were compared utilizing a competing risk model. The mean follow-up was five years.

RESULTS

Overall, 23% met the eligibility criteria for one-stage exchange arthroplasty. The most common reasons for ineligibility were host grade (52%) and unidentified organism (25%). At two years, cumulative incidences of reoperation for infection for ineligible and eligible patients were 11 and 11%, respectively. At two years, the cumulative incidences of re-revision for infection for ineligible and eligible patients were 6 and 2%, respectively. Ineligible patients had a significantly higher 2-year cumulative incidence of any re-revision compared to eligible patients (12 versus 5%, respectively; HR [hazard ratio] = 2.5). There was no significant difference in the 2-year cumulative incidence of any reoperation between ineligible and eligible patients (18 versus 15%, respectively).

CONCLUSIONS

Only 23% of two-stage exchange arthroplasties for hip PJIs met the published eligibility criteria for one-stage exchange arthroplasty. The 2.5-fold increased hazard of any re-revision among ineligible patients must be considered when evaluating data comparing the two surgical strategies.

LEVEL OF EVIDENCE: III (retrospective).