[Analysis of risk factors and construction of predictive model for deep vein thrombosis after core decompression in patients with osteonecrosis of the femoral head].

Objective: To analyze the risk factors of deep vein thrombosis (DVT) after core decompression in patients with osteonecrosis of the femoral head (ONFH) and construct a predictive model. Method: A retrospective analysis was conducted on the clinical data of 244 patients with ONFH who underwent core decompression and were hospitalized in Guizhou Hospital of Jishuitan, Beijing from January 2020 to May 2025. There were 143 males and 101 females, with an age of (62.2±4.2) years. According to whether DVT occurred within 3 months after the operation, the patients were divided into the non-DVT group (n=167) and the DVT group (n=77), and the differences in various clinical indicators between the two groups were analyzed. After screening for variables through least absolute shrinkage and selection operator (LASSO) regression, a multivariate logistic regression model was conducted to analyze the risk factors of DVT after core decompression in patients with ONFH, and a nomogram of the DVT prediction model was drawn. The predictive ability, accuracy and clinical applicability of the model were evaluated respectively by the area under the receiver operating characteristic curve (AUC), calibration curve and decision analysis curve. Result: The age, ONFH volume, proportion of diabetes, postoperative bed rest time, fibrinogen (FIB), D-dimer, complement C3, complement C4, matrix metalloproteinase-1 (MMP-1), matrix metalloproteinase-2 (MMP-2), and Caprini score of patients in the DVT group were greater than those in the non-DVT group (all P<0.05). LASSO regression screened out 10 variables for analysis, namely age, ONFH volume, postoperative bed rest time, FIB, D-dimer, complement C3, complement C4, MMP-1, MMP-2, and Caprini score. The analysis of the multi-factor logistic regression model showed that large ONFH volume (OR=1.90, 95%CI:1.34-2.68), postoperative bed rest time≥3 d (OR=11.22, 95%CI:1.46-16.04), elevated FIB (OR=2.83, 95%CI:1.29-6.21), elevated D-dimer (OR=2.17, 95%CI:1.11-4.25), elevated complement C3 (OR=5.28, 95%CI:4.22-8.08), elevated MMP-1 (OR=18.78, 95%CI:15.90-27.37) and a higher Caprini score (OR=4.44, 95%CI:1.74-11.35) were risk factors for DVT in patients with ONFH after core decompression. Based on the above parameters, a prediction model for DVT after core decompression in patients with ONFH was drawn. The predictive model predicted that the AUC of DVT after core decompression in patients with ONFH was 0.82 (95%CI: 0.77-0.88).The sensitivity was 78.3%, and specificity was 81.2%. The calibration curve has a high degree of fit with the standard model curve (P=0.521) and has good clinical applicability. Conclusions: Large ONFH volume, postoperative bed rest time≥3 d, elevated FIB, elevated D-dimer, elevated complement C3, elevated MMP-1, and high Caprini score are risk factors for DVT after core decompression in patients with ONFH. The nomogram prediction model constructed based on the above parameters has good clinical applicability.