Preoperative Diagnostic Value Of Serum D-dimer For Infected Bone Nonunion After Open Reduction Internal Fixation Of Long Bone Fractures

Objective:To evaluate the role of serum D-dimer,white blood cell count,C-reactive protein,and erythrocyte sedimentation rate in the preoperative diagnosis of infected bone nonunion after open reduction internal fixation of long bone fractures.Methods:A retrospective study was performed on 31 patients who underwent clear external fixation or elective internal fixation for infected bone nonunion(n=31)and 46 patients who underwent replacement internal fixation for aseptic bone nonunion(n=46).The KruskalWallis H test was used to assess the value of serum D-dimer among the three groups,and subject work curve(ROC)analysis was used to statistically assess the diagnostic validity of four indicators: serum D-dimer,white blood cell count,C-reactive protein,and erythrocyte sedimentation rate.Results:Serum D-dimer levels were significantly higher in patients with infected bone dysplasia than in patients with sterile bone dysplasia,at 388 ng/m L(245-773 ng /m L)and 120.5 ng/m L(73-157 ng /m L),respectively(P<0.001).The sensitivity of leukocyte count,CRP,and ESR were 48.39%(95% CI: 30.24-66.91),61.29%(95% CI: 42.19-78.21),and 67.74%(95% CI:48.56-83.27),respectively,and the specificity was 82.61%(95% CI: 68.57-92.18)and 95.65%(95% CI: 85.24-99.51),and 89.13%(95% CI: 76.36-96.37),respectively.The Youden index was used to determine 225 ng /m L as the optimal serum D-dimer threshold for the diagnosis of infected bone nonunion.The sensitivity of serum D-dimer >225 ng /m L was 77.42%(95%CI: 58.91-90.42)and the specificity was 93.48%(95% CI: 82.13-98.56).Conclusion:Serum D-dimer levels are higher in patients with infected bone nonunion and can be used as a preoperative laboratory predictor of infected bone nonunion after open reduction internal fixation.