Platelet count as a novel potential predictor of periprosthetic joint infection

Cao Houran; Deng Peng; Ye Pengcheng; Jie Ke; Zeng Jianchun; Feng Wenjun; Chen Jinlun; Qi Xinyu; Li Jie; Tan Xueqiu; Zhang Haitao; Zeng Yirong

Abstract：BACKGROUND: Obtaining synovial fluid for diagnostic test of periprosthetic joint infection is invasive and painful to patients. Platelet count is a regular blood test which has been used as a possible predictor of several infectious diseases. Presumably, it could be one of the indicators of periprosthetic joint infection. OBJECTIVE: To identify the accuracies of platelet combined with white blood cell, erythrocyte sedimentation rate or C-reactive protein in the diagnosis of periprosthetic joint infection. METHODS: Patients undergoing revision arthroplasty from March 2013 to December 2018 in the First Affiliated Hospital of Guangzhou University of Chinese Medicine were retrospectively enrolled. A diagnosis of periprosthetic joint infection was confirmed in 77 patients according to the criterions from the Musculoskeletal Infection Society; the remaining 137 patients were confirmed as aseptic cases. White blood cell, erythrocyte sedimentation rate, or C-reactive protein and platelet count were compared between the two groups. The sensitivity, specificity, positive predictive value, and negative predictive value were calculated. RESULTS AND CONCLUSION: The platelet values were significantly increased in periprosthetic joint infection cases. Sensitivity and specificity of the platelet for periprosthetic joint infection were 64.94％ and 86.13％, respectively. Platelet demonstrated a higher accuracy when compared to erythrocyte sedimentation rate and C-reactive protein. In such cases, the platelet shows a certain reference value in confirming the diagnosis of periprosthetic joint infection. Platelet was enough used as adjunct diagnostic tool in patients suspected with periprosthetic joint infection.