Heritable Thrombophilia and Increased Risk for Venous Thromboembolism Despite Thromboprophylaxis After Pelvis or Acetabulum Fracture.

Objectives: Individuals with pelvic and acetabular fractures are at high risk of venous thromboembolism (VTE). The purpose of this study was to determine whether serum markers for thrombophilia and rapid thromboelastography (r-TEG) values correlate with increased VTE risk among patients with pelvic and acetabular fractures.

Methods: .

Design: Prospective observational study.

Setting: Two urban academic level 1 trauma centers.

Patient selection criteria: Adult patients with isolated pelvis and/or acetabulum fractures (OTA/AO 61 and 62) treated surgically placed on a standardized VTE chemoprophylaxis regimen with enoxaparin over a 5-year period were included.

Outcome measures and comparisons: Serum r-TEG, coagulation laboratory values, and markers for heritable thrombophilia were drawn postoperatively and after completion of a 6-week course of enoxaparin. The primary outcome was VTE event (either deep venous thrombosis or pulmonary embolism) diagnosed using a Duplex ultrasound, chest computed tomography angiogram, or lung ventilation-perfusion ordered based on clinical suspicion of a VTE event. Laboratory markers and values were then compared between patients who went on to have a VTE event and those who did not and patients with and without markers of thrombophilia.

Results: One hundred thirty-three adult patients with isolated operative pelvic and/or acetabular fractures were enrolled in this study. The average age of patients at time of injury was 48.3 years (range 18-91). Sixty-seven percent of patients in the study were (n = 90) males. Sixty-three percent of patients (n = 84) completed both clinical and laboratory follow-up. Forty-one percent of patients (n = 54) had 1 or more markers of heritable thrombophilia. Twelve percent (n = 10) of patients who completed follow-up were diagnosed with VTE. Age, sex, and smoking status were not associated with VTE. Patients who developed VTE had a higher body mass index (P = 0.04). Having more than 1 marker of heritable thrombophilia (P = 0.004) and an r-TEG mean amplitude greater than 72 mm postoperatively was positively associated with VTE (P = 0.02).

Conclusions: Among patients treated surgically for isolated pelvic and acetabular fractures who received enoxaparin prophylaxis, the presence of more than 1 marker of heritable thrombophilia or r-TEG mean amplitude value greater than 72 mm postoperatively was associated with an increased risk of VTE.

Level of evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.