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Updated: Aug 5, 2026

A Multicenter MRI Protocol for the Evaluation and Quantification of Deep Vein Thrombosis
Published on: June 2, 2015
Nonlinear relationship and threshold effect of D-dimer on preoperative deep vein thrombosis in patients with ankle
Zi-Ruo Zhang1, Pei-Pei Li2, Dan Chen1
1Foot and Ankle Orthopedic Diagnosis and Treatment Center, Honghui Hospital, Xi'an Jiaotong University, Xi'an, Shaanxi, China.
Objective:
The purpose of this study is to explore the association between D-dimer levels and the likelihood of preoperative deep vein thrombosis (DVT) in patients with ankle fractures.
Methods:
This retrospective study included ankle fracture patients admitted to Xi'an Honghui Hospital's Foot and Ankle Surgery Center from January 2024 to November 2025. Preoperative DVT was identified using Doppler ultrasound, and the relationship between D-dimer levels and DVT was analyzed using multivariate logistic regression and generalized additive models.
Results:
Among 818 patients, 13.45% developed preoperative DVT. D-dimer was an independent risk factor of preoperative DVT (OR = 1.14, 95% CI: 1.03-1.26, P = 0.010). There was a nonlinear relationship between D-dimer and DVT risk, After adjusting for confounding factors (age, sex, CCI, diabetes and preoperative waiting time),exploratory analysis identified an inflection point at 3.92 mg/L. Below this threshold, each 1 mg/L increase in D-dimer was associated with a significantly higher odds of DVT (OR = 1.60, 95% CI: 1.24-2.06, P < 0.001).
Conclusion:
D-dimer is independently associated with preoperative DVT in ankle fracture patients, and the relationship appears to be non-linear.
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