Prognostic Factors for Success After Irrigation and Debridement With Modular Component Exchange for Infected Total Knee Arthroplasty

Irrigation and debridement with modular component exchange (IDMCE) can treat prosthetic joint infection (PJI) after total knee arthroplasty (TKA). Compared to 2-stage revision, IDMCE is associated with lower morbidity but may carry higher infection recurrence rates. We aimed to identify prognostic factors associated with successful IDMCE in patients with PJI. We identified 99 consecutive patients who underwent IDMCE following TKA PJI at a tertiary academic medical center from November 2009 through January 2016. Examined variables included age, gender, symptom duration, body mass index, Charlson comorbidity index, total protein, albumin, hemoglobin A1c, erythrocyte sedimentation rate (ESR), C-reactive protein, white blood cell count, gram stain results, final cultures, and use of long-term antibiotic suppression. Success was defined as no further operation on the ipsilateral knee. We used t tests and chi-square analyses to determine whether each preoperative factor was associated with IDMCE reoperation. At mean follow-up of 2.6 years, 64 patients who underwent IDMCE were defined as successful. Thirty-five patients required one or more additional procedures for recurrent infection; of these, 20 patients underwent 2-stage revision. Patients with symptom duration of less than 2 days avoided additional surgery in 88% of cases. Elevated ESR >47 mm/h was the only variable associated with reoperation (P = .005). There were no associations among the other examined variables. Using IDMCE for PJI after TKA required reoperation in 35% of cases. Elevated preoperative ESR laboratory values and duration of symptoms >2 days were associated with reoperation.