The Kidney, Liver, Index surgery and C reactive protein score is a predictor of treatment response in acute prosthetic joint infection.

PURPOSE: This work seeks to verify the utility of the KLIC score as a predictor of treatment success or failure in patients with knee and hip acute prosthetic joint infections (APJI). These patients were treated in our centre, which is not a prosthetic joint infection reference centre. The KLIC score assesses factors such as chronic kidney failure (2 points) (Kidney), liver disease (1.5 points) (Liver), revision surgery or femoral neck fracture (1.5 points)and cemented prosthesis (2 points) (Index surgery) and a C-reactive protein level (CRP) greater than 11.5 mg/dL (2.5 points), as a predictor of treatment success or failure in patients with knee and hip acute prosthetic joint infections (APJI).

METHODS: We retrospectively reviewed 30 patients with APJI who were treated using debridement, antibiotics, irrigation and retention (DAIR) treatment between January 2007 and December 2016. Patients' KLIC scores were calculated. The main outcome was success or failure of DAIR treatment of APJI.

RESULTS: DAIR treatment succeeded in 21 cases and failed in nine cases. Differences in outcome were found according to the KLIC score. For KLIC scores >2 and ≤4, there were three successes and zero failures; for scores 4-5, there were nine successes and two failures; for scores >5 and ≤7,there were nine successes and four failures; and for scores >7, there were zero successes and three failures (p = 0.025). We found a positive predictive value and negative predictive value of 33% and 100% for scores ≤4 (score for calculations: 3.5), 43% and 84% for scores 4-5 (4.5), 50% and 68% for scores >5 and ≤7 (5.5), and 100% and 76% for scores >7 (7.5), respectively. The area under the ROC curve was 0.762 (95% confidence interval, 0.569-0.955).

CONCLUSIONS: The KLIC score was useful in predicting success or failure of DAIR treatment of APJI. This supports the conclusion that with a score < 3.5, treatment is likely to succeed and with a score of >6, it is likely to fail.