Excluding infections in arthroplasty using leucocyte esterase test.

Purpose: Periprosthetic joint infections remain a major challenge for the surgeon in modern arthroplasty. The decision on how to handle a case is often difficult due to the variety of clinical presentations. The aim of this study was to establish the leucocyte esterase test as an intra-operative rapid diagnostic tool in an unclear infected or aseptic situation.

Methods: In the setting of 364 endoprosthetic joint procedures on knee, hip and shoulder, we aspirated synovial fluid before performing capsulotomy. We performed a leucocyte esterase test. The results were correlated with the pre-operative synovial fluid aspirations, the laboratory blood sample parameters (C-reactive protein, white blood cells) and the intra-operative histopathological and microbiological findings.

Results: The leucocyte esterase test has a sensitivity of 100% and a specificity of 96.5%. The positive predictive value was 82% and the negative predictive value was 100%. Correlation with conventional methods such as serum C-reactive protein and serum white blood cells is given. The histopathological evaluation confirmed the microbiological results in all but three cases.

Conclusions: Based on our results and the current literature, we recommend the leucocyte esterase test as a useful tool in the diagnosis of periprosthetic joint infection.