Repeat irrigation & debridement for patients with acute septic knee arthritis: Incidence and risk factors

BACKGROUND: Septic knee arthritis is considered an orthopedic emergency due to its significant morbidity and potential to be life-threatening. One important outcome in treatment of septic knee arthritis is whether return to the operating room for repeat irrigation and debridement is required. This complication presents extra burden to the patient, as well as to the health care system. This study aims to first isolate the incidence of repeat irrigation and debridement at the authors’ home institution and then define risk factors for repeat washout for septic arthritis of the knee. METHODS: Records from all patients at a single academic institution with acute septic knee arthritis who had arthroscopic or open I&D of the knee joint from January 2005–December 2015 were collected retrospectively. Patients were initially identified on the basis of diagnosis coding in the institution’s medical information system. Following collection/screening based on strict inclusion/exclusion criteria, a cohort of 63 patients was ultimately included. 18 patients were assigned to a “repeat washout” (RW) cohort and 45 patients were assigned to a “no repeat washout” (NRW) cohort. Univariate analyses and multivariable regression models were performed between the two washout cohorts to identify variables associated with repeat washout. RESULTS: Patients requiring a repeat washout (RW) had a statistically significant association with African American/Hispanic race, higher BUN levels, higher serum white blood cell (WBC) count on admission, concurrent infection, and isolated bacteremia when compared to those patients who did not require a repeat washout (NRW) (all respective P