Time to Reimplantation: Waiting Longer Confers No Added Benefit.

Background: While the preferred surgical treatment for chronic periprosthetic joint infection (PJI) in North America is a 2-stage exchange arthroplasty, the optimal time between first-stage and reimplantation surgery remains unknown. This study was conceived to examine the association between time to reimplantation and treatment failure.

Methods: Using an institutional database, we identified PJI cases treated with 2-stage exchange arthroplasty between 2000 and 2016. Musculoskeletal Infection Society criteria were used to define PJI, and treatment failure was defined using Delphi criteria. The interstage interval between first-stage and reimplantation surgery for each case was collected, alongside demographics, patient-related and organism-specific data. Multivariate logistic regression analyses were used to examine association with treatment failure.

Results: Our final analysis consisted of 282 patients with an average time to reimplantation of 100.2 days (range, 20-648). Sixty-three patients (22.3%) failed at 1 year based on Delphi criteria. Time to reimplantation was not significantly associated with failure in both univariate (P = .598) and multivariate (P = .397) models. However, patients reimplanted at >26 weeks were twice as likely to fail in comparison to those reimplanted within <26 weeks (43.8% vs 21.1%), and this finding reached marginal significance (P = .057). Patients who failed had significantly more comorbidities (P = .008). Charlson comorbidity index was the only variable significantly associated with treatment failure in regression analysis (odds ratio, 1.40; 95% confidence interval, 1.06-1.86; P = .019).

Conclusion: The length of the interstage interval was not a statistically significant predictor of failure in patients undergoing 2-stage exchange arthroplasty for PJI.