Objective: To investigate the relationship between the infection rate and the timing of replacement of temporary external fixators with internal fixation, and the timing of immediate or delayed internal fixation after removal of temporary external fixation in the staging treatment modality of open fractures of extremities. Methods: A retrospective analysis was performed on 122 cases of open fractures of extremities. External fixators were applied at the early stage and replaced with internal fixation when the condition of soft tissues improved and inflammatory indexes dropped to the normal range or showed a steady downward trend. Depending on the carrying time of external fixators after wound closure or healing, the patients were divided into three groups; the carrying time of groups A, B, and C was ≤ 14 days, 15–28 days, and > 28 days, respectively. Depending on the immediate or delayed internal fixation after removal of external fixator, patients were divided into group a (immediate internal fixation after removal of external fixator) and group b (delayed internal fixation after removal of external fixator, 5–7 days later). Results: The infection rates of groups A, B, and C were 6.5%, 5.9%, and 23.3%, respectively. The differences among the three groups were statistically significant (P < 0.05). The infection rates of different Gustilo–Anderson fractures were as follows: no cases of infection out of 10 cases with type I fracture (0%); two cases of infection out of 35 cases with type II fracture (5.7%); three cases of infection out of 36 cases with IIIa fracture (8.3%); five cases of infection out of 28 cases with IIIB fracture (17.9%); and five cases of infection out of 13 cases with IIIC fracture (38.5%). The differences among the five groups were statistically significant. Conclusions: The occurrence of infection of open fractures of extremities is associated with the fracture severity (Gustilo classification). For open fractures of Gustilo types I and II, the final internal fixation should be placed as soon as possible when the recovery of general and local conditions is good and the infection is controlled.

Purpose. To investigate infection risk factors after secondary internal fixation (IF) of open fracture of a long bone with removed fixation frame and explore the safe range of feasible operation for abnormal inflammatory indicators. Methods. Clinical data of 117 cases of open fracture of a long bone that underwent temporary external fixation (EF) in one stage and IF in two stages were retrospectively analyzed. Collected data included age, sex, Gustilo type, multiple injuries, debridement time, duration of EF, needle infection, interval of conversion to IF after external fixator, preoperative white blood cell (WBC), erythrocyte sedimentation rate (ESR), C‐reactive protein (CRP), albumin (ALB), blood glucose, and prognosis. We selected these factors for univariate analysis of postoperative surgical site infection (SSI) and multivariate logistic regression analysis of statistically significant risk factors and created receiver operating characteristic (ROC) curves to compare the diagnostic efficiency of each index and determine the optimal screening point. Results. We followed up 117 patients, with 130 limbs affected. Univariate analysis showed that ESR, CRP, ALB, WBC, EF time, and Gustilo fracture type were significantly associated with SSI. Multivariate logistic regression analysis showed that CRP, duration of EF, and Gustilo fracture type were independently associated with postoperative infection. Area under ROC curves for WBC, ESR, and CRP were 69.7%, 73.2%, and 81.2%. Conclusions. We demonstrated the role of Gustilo classification of open fractures in predicting postoperative infection, especially for open fractures above type III. If the inflammatory indexes return to normal or show a downward trend, and the second‐stage IF operation is performed within the cutoff values, postoperative recurrent infection was reduced.