[Role of blood markers in predicting the failure of prosthesis removal and antibiotic-loaded bone cement spacer implantation for treatment of periprosthetic joint infection].

Objective: To investigate the value of inflammation,coagulation and nutrition markers in predicting the failure of prosthesis removal and antibiotic-loaded bone cement spacer implantation for treatment of periprosthetic joint infection(PJI). Methods: A retrospective study was conducted on 70 patients who undertook prosthesis removal and antibiotic-loaded bone cement spacer implantation due to PJI from June 2016 to October 2020 in the Department of Orthopedics,Henan Provincial People's Hospital. There were 28 males and 42 females,aged (65.5±11.9) years (range: 37 to 88 years). Patients were divided into two groups as the successful group and the failed group depended on whether reinfection occurred after prosthesis removal and antibiotic-loaded bone cement spacer implantation at the last follow up. Patient demographics,laboratory values (C-reactive protein (CRP),erythrocyte sedimentation rate (ESR),ESR and CRP ratio (ESR/CRP),white blood cell count(WBC),platelet count(PLT),hemoglobin(HB),total lymphocyte count(TLC),albumin、fibrinogen(FIB),CRP and albumin ratio (CAR),prognostic nutritional index(PNI)),and reinfection rates were assessed. Comparison between groups was conducted by the independent sample t test or χ ² test. Receiver operating characteristic (ROC) curve was plotted,and the area under the curve (AUC),optimal diagnostic threshold,sensitivity,and specificity were analyzed to predict the failure of prosthesis removal and antibiotic-loaded bone cement spacer implantation. Results: All patients were followed up for at least two years,and the follow-up time was (38.4±15.2) months (range: 24 to 66 months). Fifteen patients suffered failure after prosthesis removal and antibiotic-loaded bone cement spacer implantation,while the other 55 patients succeeded. The overall failure rate of prosthesis removal and antibiotic-loaded bone cement spacer implantation in PJI treatment was 21.4%. Level of preoperative CRP ((35.9±16.2)mg/L),PLT ((280.0±104.0)×10 ⁹ /L) and CAR (1.3±0.8) in successful group were lower than CRP ((71.7±47.3)mg/L),PLT ((364.7±119.3)×10 ⁹ /L) and CAR (2.5±2.0) in failed group (all P <0.05).Whereas,level of preoperative ESR/CRP (3.3±3.1), Albumin ((35.3±5.2)g/L) and PNI (43.6±6.2) in successful group were higher than ESR/CRP (1.6±1.4),Albumin ((31.3±4.8)g/L) and PNI (39.2±15.1) in failed group (all P <0.05). AUC of ROC curve,optimal threshold value,sensitivity and specificity of CRP,ESR/CRP, PLT, Albumin,CAR and PNI for the predicting failure of prosthesis removal and antibiotic-loaded bone cement spacer implantation were 0.776(95% CI :0.660 to 0.867),35.4 mg/L,86.7%,67.3%;0.725(95% CI :0.605 to 0.825),1.0,60.0%,78.2%;0.713(95% CI :0.593 to 0.815),253,93.3%,47.3%;0.721(95% CI :0.601 to 0.822),35.7,93.3%,49.1%;0.772(95% CI :0.656 to 0.863),1.1,86.7%,67.3%;0.706(95% CI :0.585 to 0.809),45.7,100%,41.8% respectively. Conclusion: In patients with PJI,CRP>35.4,ESR/CRP≤1.0 and CAR>1.1 could predict the failure of prosthesis removal and antibiotic-loaded bone cement spacer implantation.