Abstract
Open debridement, irrigation with implant retention and antibiotic treatment (DAIR) is an accepted approach for early prosthetic joint infections (PJI). Our aim was to design a score to predict patients with a higher risk of failure.
From 1999 to 2014 early (<90 days) PJIs without signs of loosening of the prosthesis were treated with DAIR and were prospectively collected and retrospectively reviewed. The primary end-point was early failure defined as: 1) the need of an unscheduled surgery, 2) death-related infection within the first 60 days after debridement or 3) the need for suppressive antibiotic treatment. A score was built-up according to the logistic regression coefficients of variables available before debridement.
A total of 222 patients met the inclusion criteria. The most frequently isolated microorganisms were coagulase-negative staphylococci (95 cases, 42.8%) and Staphylococcus aureus (81 cases, 36.5%). Fifty-two (23.4%) cases failed. Independent predictors of failure were: chronic renal failure (OR:5.92, 95%CI:1.47–23.85), liver cirrhosis (OR:4.46, 95%CI:1.15–17.24), revision surgery (OR:4.34, 95%CI:1.34–14.04) or femoral neck fracture (OR:4.39, 95%CI:1.16–16.62) compared to primary arthroplasty, CRP >11.5 mg/dL (OR:12.308, 95%CI:4.56–33.19), cemented prosthesis (OR:8.71, 95%CI:1.95–38.97) and when all intraoperative cultures were positive (OR:6.30, 95%CI:1.84–21.53). Furthermore, CRP showed a direct relationship with the percentage of positive cultures (Linear equation, R2=0,046, P=0.002) and an inverse association with the time between the debridement and failure (Logarithmic equation, R2=0.179, P=0.003). A score for predicting the risk of failure was done using pre-operative factors (KLIC-score, figure 1) and it ranged between 0–9.5 points. Patients with a score ≤2, >2–3.5, 4–5, >5–6.5 and ≥7 had a failure rate of 4.5%, 19.4%, 55%, 71.4% and 100%, respectively.
The KLIC-score was highly predictive of early failure after debridement. In the future, it would be necessary to validate our score using cohorts from other institutions.
