Does Body Mass Index Affect the Success of Two-Stage Management of Periprosthetic Joint Infection?

Introduction: Obesity is associated with increased infection risk after primary total joint arthroplasty. In this retrospective cohort analysis, we sought to assess the association between body mass index (BMI) and infection recurrence after two-stage revision total joint arthroplasty (TJA) for periprosthetic joint infection (PJI).

Methods: Patients were grouped by BMI (< 30, 30 to 40, and ≥ 40) as non-obese, obese, and morbidly obese, and assessed for associations and timing of PJI reinfection as well as readmissions and complications.

Results: Following the two-stage revision, PJI reinfections increased from 11.5% in non-obese to 19.0% in obese and 25.9% in morbidly obese patients (P = 0.011). As BMI increased across the three groups, 90-day readmission rates following two-stage PJI revision significantly increased (8.6, 19.7, and 16.7%, respectively (P = 0.042)). The average time to reinfection decreased with obesity tercile (restricted-mean times of 4.5, 4.2, and 3.8 years with non-obese, obese, and morbidly obese, respectively (P = 0.023)).

Discussion: The success of PJI management with two-stage arthroplasty is significantly impacted by patient BMI, with morbidly obese subjects having the worst outcomes. Attempts to modify BMI before completion of two-stage PJI treatment should be considered in the morbidly obese given high rates of recurrence.