Establishment of preoperative diagnosis of low-grade infectious nonunion / 中华创伤骨科杂志

ABSTRACT

Objective:To explore the reliability of preoperative diagnosis of low-grade infectious nonunion using haematological testing and radioisotope scanning (bone 3-phase image).Methods:A retrospective study was conducted of the 265 patients with bone nonunion who had been treated at Department of Orthopaedics, The Sixth People’s Hospital Affiliated to Shanghai Jiaotong University and at Department of Orthopaedics, The Eighth People’s Hospital Affiliated to Shanghai Jiaotong University from June 2010 to June 2018.They were 151 males and 114 females, aged from 19 to 64 years (average, 39.7 years).The nonunions occurred mainly at the tibia (113 cases) and the femur (72 cases).The preoperative results of their white blood cell count (WBC), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and radioisotope scanning were recorded.Taking the intraoperative pathological observations as the gold standards, the sensitivity, specificity, area under curve (AUC) of receiver operator characteristic (ROC) and Youden index were statistically analyzed respectively for every preoperative haematological tests and radioisotope scanning as well as for different combinations of the radioisotope scanning and one or more haematological tests.Results:Compared with the pathological observations, the radioisotope scanning showed a sensitivity of 80.7%, a specificity of 73.3%, an AUC of 0.770 and a Youden index of 0.540.In the combinations of radioisotope scanning and one haematological test, that of radioisotope scanning and CRP produced the largest AUC of 0.683, a sensitivity of 98.0%, a specificity of 70.3%, and a Youden index of 0.848.In the combinations of radioisotope scanning and 2 haematological tests, that of radioisotope scanning and WBC and ESR produced the largest AUC of 0.895, a sensitivity of 94.3%, a specificity of 67.3%, and a Youden index of 0.616 and all the 3 ones yielded an AUC of more than 0.880.The combination of radioisotope scanning and all the 3 haematological tests produced a sensitivity of 96.5%, a specificity of 79.7%, an AUC of 0.925 and a Youden index of 0.762.Conclusion:Combination of haematological testing and radioisotope scanning can be a reliable preoperative diagnosis of low-grade infection nonunion.