Since NICE issued guidance on preventing venous thromboembolism (VTE), the use of chemoprophylaxis has increased dramatically in trauma and orthopaedics. However, enthusiasm is tempered by a lack of data regarding the true incidence of VTE in everyday practice. We investigated the epidemiology of VTE among ambulatory patients with lower limb injuries within our Trust.

We identified all patients who suffered pulmonary embolism (PE) or deep vein thrombosis (DVT) over an 18 month period, and cross-referenced them with our trauma database. All lower limb injuries were included, whether operated or not. Hip fractures routinely receive dalteparin and were excluded.

There were 11,594 new attendances or post-operative attendances in all fracture clinics over 18 months. Of these, 4530 had lower limb injuries and were immobilised. There were 21 DVTs and 7 PEs in these patients, an incidence of 0.43% and 0.14% respectively. Of note, three DVTs were in patients with Achilles tendon rupture.

The incidence of symptomatic VTE is low in a population of ambulant patients with lower limb injuries in casts, without chemical thromboprophylaxis. Prophylaxis for VTE would thus have a large number needed to treat. The costs and complications of chemoprophylaxis should also be considered before it is introduced universally.