Objectives To explore the clinical effect of external fixator combined antibiotic-calcium sulfate packing medullary cavity, VSD continuous drain with negative pressure and local skin flap transposition for the treatment of postoperative infected nonunion after initial debridement. Methods 20 cases of traumatic osteomyelitis from August 2012 to August 2014 were selected and taken antibiotic-calcium sulfate to focal zone. The patients were taken first-stage bone grafting for small bone defects and osteotomy for lengthening for big bone defects. For patients with cutaneous injury, local skin flap transposition was taken. For other patients with partial flap necrosis and non healing wounds, VSD continuous drain with negative pressure was taken. Results Operative incisions of 12 cases were primary healing, two cases were healing by second intention, four cases of flap were survived after local skin flap transposition, and two cases of flap were partial necrosis and healed by second intention. 11 cases of immobilization with external fixator, bone healing was satisfactory in seven cases after osteotomy for lengthening and two cases of bone delayed union in osteotomy for lengthening and recovered after bone transplantation. All patients were followed up for average 19(6-32) months with permatoplasty survived; all the infection of wounds was controlled and relapse-free. The fracture healing period was eight(4-12) month without pin site infection, osteoporosis and deformed healing. But there were 1 cases of knee stiffness and two cases stiffness of ankle joint. Conclusion After initial debridement, taken external fixator and taken antibiotic-calcium sulfate to medullary cavity and fracture ends. The patients were taken first-stage bone grafting for small bone defects and osteotomy for lengthening for big bone defects. For the skin defect after local flap grafting, taken VSD continuous drain with negative pressure for partial necrosis of flap occurred and non healing wounds cases. The method obtained prominent curative effect, reduces the treatment cycle and reduce the complications in the treatment of postoperative infected nonunion.

Objective:To investigate the risk factors for lower extremity deep vein thrombosis (DVT) in patients with bone trauma and their diagnostic efficacy.Methods:A retrospective cohort study was conducted to analyze the clinical data of 108 patients with bone trauma who were admitted to Affiliated Changzhou Second People′s Hospital of Nanjing Medical University from October 2023 to February 2024, including 61 males and 47 females, aged 17-96 years [(55.2±19.5)years]. Based on the results of color Doppler ultrasonography of lower extremities within 96 hours on admission, the patients were divided into DVT group ( n=58) and non-DVT group ( n=50). In DVT group, 42 patients developed lower extremity DVT within 7 days after trauma and the other 16 patients developed lower extremity DVT after 7 days. Basic clinical data including gender, age, body mass index (BMI), underlying diseases, cause of injury, site of fracture, surgery and admission Caprini score, and admission laboratory test indicators including routine coagulation indicators [prothrombin time (PT), international normalized ratio (INR), thrombin time (TT), activated partial thromboplastin time (APTT), fibrinogen (FBG) and D-dimer (D-D)] and four thrombosis indicators [plasma thrombin-antithrombin III complex (TAT), thrombomodulin (TM), tissue-type plasminogen activator-inhibitor 1 complex (tPAIC) and plasmin-alpha2-plasmin inhibitor complex (PIC)] were collected in the two groups. Univariate analysis and multivariate binary Logistic regression analysis were conducted to investigate the correlation between these indicators and incidence of lower extremity DVT in patients with bone trauma and determine the independent risk factors. Receiver operating characteristic (ROC) curve and area under the curve (AUC) of the relevant risk factors were analyzed to evaluate and compare the diagnostic efficacy of the factors for lower extremity DVT in patients with bone trauma and further assess the diagnostic efficacy of the factors for lower extremity DVT within 7 days after bone trauma. Results:Univariate analysis revealed significant correlations of gender, age, Caprini score, D-D, TAT, TM and PIC with incidence of lower extremity DVT in patients with bone trauma ( P<0.01). The results of multivariate binary Logistic regression analysis demonstrated that Caprini score ( OR=1.36, 95% CI 1.12, 1.65, P<0.01), TAT ( OR=1.05, 95% CI 1.00, 1.10, P<0.05), and TM ( OR=1.34, 95% CI 1.02, 1.77, P<0.05) were significantly correlated to incidence of lower extremity DVT in patients with bone trauma. ROC curve analysis indicated that TAT (AUC=0.76, 95% CI 0.67, 0.86) had the highest diagnostic efficiency, followed by TM (AUC=0.72, 95% CI 0.62, 0.81) and Caprini score (AUC=0.72, 95% CI 0.62, 0.82). The combined analysis of all the factors effectively enhanced the diagnostic efficiency for DVT (AUC=0.84, 95% CI 0.77, 0.92). Additionally, TAT (AUC=0.81, 95% CI 0.71, 0.91) demonstrated better diagnostic efficacy for lower extremity DVT within 7 days after bone trauma compared with the Caprini score (AUC=0.72, 95% CI 0.61, 0.83) and TM (AUC=0.71, 95% CI 0.60, 0.83). Similarly, the combined analysis of all the factors also effectively enhanced the overall diagnostic efficacy for lower extremity DVT within 7 days after bone trauma (AUC=0.85, 95% CI 0.77, 0.93). Conclusions:Caprini score, TAT and TM are identified as independent risk factors for lower extremity DVT in patients with bone trauma, and all the three factors demonstrate good diagnostic efficacy. Their combination is found to have statistically significant higher diagnostic efficiency than each individual factor. Furthermore, TAT is proved to be the best in diagnosing lower extremity DVT within 7 days after bone trauma, while the combined analysis of all the risk factors can further improve the diagnostic efficacy.