Usefulness of serum D‑dimer for preoperative diagnosis of infected nonunion after open reduction and internal fixation Zhen Wang,1,* Chong Zheng,2,* Siyuan Wen,1 Junfei Wang,1 Zitao Zhang,1 Xusheng Qiu,1 Yixin Chen11Department of Orthopedics, Drum Tower Hospital Clinical College of Nanjing University, Nanjing, People’s Republic of China; 2Department of Orthopedics, Changzhou Traditional Chinese Medicine Hospital Affiliated to Nanjing University of Chinese Medicine, Changzhou, People’s Republic of China*These authors contributed equally to this workPurpose: Infected nonunion after open reduction internal fixation (ORIF) is a serious complication. The aim of this study was to evaluate the usefulness of serum D-dimer for preoperative diagnosis of infected nonunion.Patients and methods: Patients undergoing debridement and external fixation for infected nonunion