Abstract
Aim
The aim of the study is to evaluate the specificity and sensibility of leukocyte esterase for the diagnosis of periposthetic joint infection (PJI).
Method
Between October 2016 and April 2017 we enrolled 65 patients underwent to hip and knee revision arthroplasty due to uncertain joint infection. Synovial fluid was obtained from 64 joints that underwent revision arthroplasty.
Each patient was evaluated in the preoperative time with CRP, ESR and leukoscan, in the intraoperative time with frozen section and leukocyte esterase strip and post-operative with sonication fluid culture, periprosthetic tissues cultures and histological examination. Results of all of these exams were compared to assess the specificity, the sensibility, the positive and negative predicting values of leukocyte esterase for the diagnosis of PJI.
Results
The leukocyte esterase test with a threshold of +/++ had a sensitivity of 80.2%, a specificity of 82.8%, a positive predictive value of 63.8%, and negative predictive value of 92.1%. Using the threshold of ++ as a positive leukocyte esterase result, the specificity reached 97.8%, the positive predictive value 90.8%, and the negative predictive value 89.0%.
Conclusions
These results demonstrate that leukocyte esterase is a quite accurate, effective marker of periprosthetic joint infection and that it is a valuable tool that can be used in conjunction with the the other tests for diagnosis of PJI.
