To use the Caprini risk assessment model to analyze the occurrence of deep vein thrombosis (DVT) in patients with avascular necrosis of the femoral head (ANFH) after total hip arthroplasty (THA).

The ANFH patients who have been treated with THA in Chifeng Municipal hospital in recent years were reviewed. Inclusion creteria: Ficat Ⅳ ANFH, THA surgery for the first time, unilateral THA surgery, postoperative use of low molecular weight heparin and physical measures to prevent DVT. Exclusion cretieria: preoperative ultrasound examination found that DVT of the lower extremities existed, cement prosthesis was used. According to whether lower limb DVT occurred within 35 days after THA, they were divided into DVT group and non-DVT group. Mann-Whitney U test was used to compare the Caprini risk assessment model scores of the two groups of patients.

A total of 93 study subjects were included, including nine cases (9.68%) in the DVT group and 84 cases (90.32%) in the non-DVT group. The age (t=-1.198), gender (Fisher's exact test P>0.05), operation time (t=-1.391), intraoperative blood loss (Z=-1.745) of the two groups of patients were similar, and the difference was not statistically significant (P>0.05). The patients in the DVT group scored higher in the risk factors with a single score of three(Z=-3.183, P<0.05) and in the total Caprini score, and the differences were statistically significant (Z=-2.242, P<0.05).

For ANFH patients undergoing THA therapy, the risk factors scored as three points in the Caprini risk assessment model, such as the history of venous thromboembolic disease or the family history of thrombosis, should be paid attention to in order to detect and treat DVT as soon as possible.