SLR - April 2016 - Alan C. Stuto

Title: Risk Factors for Thromboembolic Events After Surgery for Ankle Fractures

Reference: Basques BA, Miller CP, Golinvaux NS, Bohl DD, Grauer JN. Risk Factors for Thromboembolic Events After Surgery For Ankle Fractures. Am J Orthop (Belle Mead NJ). 2015 Jul; 44(7): E220-224.

Scientific Literature Review

Reviewed By: Alan C. Stuto, DPM
Residency Program: University Hospital, Newark, NJ

Podiatric Relevance: DVT prophylaxis during the perioperative period for podiatric surgeons is a controversial topic and discussed on a routine basis. In orthopaedics, most research comes from total joint arthroplasty and hip fracture studies, which are known to have a higher incidence of venous thromboembolic events (VTEs). One study referenced VTE incidence can be as high as 70 percent for total hip arthroplasty, 26 percent for hip fracture, and 5 percent for ankle fracture. Based on the low incidence of VTE’s after ankle fractures and insufficient evidence in this population, the American Orthopaedic Foot and Ankle Society and American College of Chest Physicians do not recommend routine screening or prophylaxis for VTE in patients with ankle fractures.

Given the limited data available, the authors conducted a retrospective national cohort study to determine the incidence of and independent risk factors for VTE’s after ankle ORIF. If patients who are at higher risk can be identified, they can and should be carefully monitored and should be considered for VTE prophylaxis.

Methods: This retrospective study used the American College of Surgeons National Surgical Quality Improvement Program database, which captures data from more than 370 participating US hospitals. One-hundred-fifty patient variables are collected from op reports, medical records and patient interviews. Clinical data was collected for entire 30 days post op period. Patients who had an ankle fracture ORIF between 2005-2012 were identified by using post op diagnosis. Four thousand, seven hundred and eighty-five patients were identified but patients were excluded if had incomplete perioperative data. Patient characteristics were identified such as: BMI, Age, History of Pulmonary disease, History of heart disease, History of Diabetes, ASA class, steroid use, disseminated cancer, functional status. VTE was defined as the occurrence of a DVT or PE during this period, and was diagnosed with diagnostic studies.

Statistical analysis was performed with Stata Version 11.2. Demographic and comorbidity variables were tested for association with occurrence of VTE using bivariate and multivariate logistic regressions.

Results: Four thousand, four hundred and twelve ankle fracture patients met the inclusion criteria who underwent ankle ORIF between 2005 and 2012, and found overall VTE incidence of 0.8 percent. Mean age 50.9 yrs, BMI 30.4kg/m2, 40 percent male. 5.3 percent of the patients had medial malleolus fxt; 25.9 percent of the patients had lateral malleolus fxt; 38.6 percent of the patients had bi-malleolar fracture; 30.1 percent of the patients had tri-malleolar fracture. Of the 33 patients (0.8 percent) with VTE recorded within the first 30 postoperative days, 16 had DVT, 14 had PE, and 3 had both. VTE’s were reported a mean 11.5 days after surgery.

Bivariate logistic regressions were performed to test the association of each patient variable with the occurrence between VTE, ankle ORIF, and patient’s variable. Multivariate logistic regression was used to control for potential confounding variables and determine which factors were independently associated with VTE’s. Class I, II, III obesity, history of heart disease, and dependent functional status (inability to mobilize independently) were independently associated with increased rate of VTE’s.

Conclusions: VTE’s are serious complications that can occur after ORIF of ankle fractures. Although the American Orthopaedic Foot and Ankle Society and American College of Chest Physicians do not recommend routine screening or prophylaxis for VTE in patients with ankle fractures, the results of this study showed there may be a benefit in emphasizing VTE prophylaxis in certain cohorts of patients.

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