2007 WINNER OF THE COSA AWARD
THIRD PRIZE

Deep Vein Thrombosis Prophylaxis in Distal Lower Extremity Fractures - A Prospective Randomized Controlled Trial

Danny Goel, M.D.
Calgary, AB

R. Buckley
G. deVries
G. Abelseth
G. Fick
A. Ni
R. Gray

Purpose
The incidence of DVT and need for thrombo-prophylaxis following isolated distal lower extremity fractures is unknown.  The purpose of this study was to determine whether or not thrombo-prophylaxis with low-molecular-weight Heparin was needed in this trauma population.

Methods
A Multi-centered Prospective Randomized Double Blind Placebo Controlled Trial was designed to define the incidence of DVT and need for thrombo-prophylaxis in this population. A sample size calculation ensured a one tailed type I error of 0.05 and power of 80% as confirmed from previous studies. Male and female patients between the ages of 18-75 years with isolated distal lower extremity fractures (excluding the foot) were eligible. All patients had surgery within 48 hours after injury. Patients excluded from the trial were polytrauma patients, those medically unfit for the operating room, patients with foot fractures, those receiving anticoagulation, inability to provide consent, platelets <100 X 10 9 or creatinine levels above >200 umol /L. Randomization was carried out via computer generation to receive either placebo or Fragmin for 14 days. At 14 days, all patients underwent bilateral venograms interpreted by 3 independent radiologists. Equivocal venograms were interpreted by consensus. Routine follow-up was carried out for all patients at 2, 6, 8 and 12 weeks.

Results
A total of 237 patients were enrolled in the study. One hundred twenty-six patients in the Fragmin group and 111 in the placebo group completed the intervention. There was no statistically significant difference in DVT incidence between those patients treated with Fragmin or placebo (p = 0.22). Gender, medical issues, pre-operative level of activity and body mass index had no effect on the incidence of DVT.

Conclusion and Significance
The incidence of DVT in Fragmin treated and placebo treated patients is 8.1% and 11.2%, respectively (p = 0.22). This study suggests that DVT thrombo-prophylaxis is not indicated in this patient population. To our knowledge, this is the first Randomized Controlled Trial utilizing venograms (gold standard) for DVT identification.