SLR - June 2012 - Timothy J. Levar
Reference: Pelet S, Roger ME, Belzile EL, Bouchard M. J Bone Joint Surg Am 94:502-6. 2012
Scientific Literature Review
Reviewed by: Timothy J. Levar, DPM
Residency Program: Cleveland Clinic Foundation/Kaiser Permanente
Podiatric Relevance:
Thromboembolic events, including deep venous thrombosis (DVT) and pulmonary embolism (PE), are serious complications associated with foot and ankle surgery. These complications carry significant morbidity and mortality. The incidence of thromboembolic events after ankle fractures has not been clearly established within the literature. The aim of this study was to determine the incidence of thromboembolic events and explore the relationships of various risk factors and thromboprophylactic measures in patients requiring surgical treatment after an ankle fracture.
Methods:
The study design consisted of a retrospective review of 2478 patients who underwent open reduction and internal fixation of an ankle fracture at any one of three university hospitals. One thousand, five hundred and forty patients met the inclusion criteria with equal distributions of men and women, median age was 46 years, and a minimum follow up of six months. Fracture patterns were 45.3 percent unimalleolar, 30.7 percent bimalleolar, and 24.0 percent trimalleolar. All patients were immobilized and remained non-weight bearing for one month postoperatively. The charts of these patients were reviewed to determine risk factors, use of thromboprophylaxis, and occurrence of a thromboembolic event. Risk factors included neoplasia, hormonal or oral contraceptive medication, pregnancy, blood dyscrasia, previous history of DVT or PE, current history of smoking, obesity (BMI>35.0kg/m2), dyslipidemia, atherosclerotic vascular disease, and paralysis. The thromboprophylactic agents used consisted of low-molecular weight heparin and warfarin. Aspirin was not considered. Thromboembolic event was defined as symptomatic when DVT (painful calf with or without swelling) was confirmed with Doppler ultrasonography or when PE was confirmed with ventilation and perfusion scintigraphy or helical computerized tomography.
Results:
There were clinically detectable thromboembolic events in 2.99 percent (46 patients) with 2.66 percent (41 patients) presenting with a DVT and 0.32 percent (five patients) with a nonfatal PE. No deaths occurred. Two hundred fifty-three patients (16.4 percent) received one of the types of thromboprophylaxis during the hospital stay. Those taking low-molecular weight heparin continued therapy for six weeks and three months for those taking warfarin after discharge. The thromboembolic event rate in this subgroup was 2.37 percent for DVT and 0.40 percent for PE. These results were not significantly different from the thromboembolic event rates in patients that did not receive prophylaxis (2.56 percent vs. 2.37 percent, RR=0.91). The pre-injury use of aspirin did not modify the thromboembolic event rates. The presence of one risk factor was detected in 698 patients (45.3 percent). Risk factors were associated with higher rates of thromboembolic events in this group of patients (3.59 percent vs. 2.38 percent; RR=0.66). The presence of two or more risk factors did not change the results. Thromboembolic event rates in patients with and without risk factors were not influenced by the use of thromboprophylaxis (3.68 percent vs. 3.55 percent, respectively; RR=0.96). There was no significant difference in thromboembolic event rates between age, sex, fracture type, level of energy, trauma, or thromboprophylaxis.
Conclusions:
This Level III study demonstrated relatively no benefit of thromboprophylaxis after surgical treatment of ankle fractures in comparison to patients who did not receive prophylaxis. Also, patients with one or more risk factors appeared to be at higher risk of a thromboembolic event. Currently, the American College of Chest Physicians does not recommend the use of thromboprophylaxis routinely for isolated lower extremity fractures. However, these guidelines are based upon a small number of studies and further prospective investigation may be warranted.