Recent recommendations by the National Institute
for Health and Care Excellence (NICE) suggest that all patients undergoing
elective orthopaedic surgery should be assessed for the risk of
venous thromboembolism (VTE). Little is known about the incidence of symptomatic VTE after
elective external fixation. We studied a consecutive series of adult
patients who had undergone elective Ilizarov surgery without routine
pharmacological prophylaxis to establish the incidence of symptomatic
VTE. A review of a prospectively maintained database of consecutive
patients who were treated between October 1998 and February 2011
identified 457 frames in 442 adults whose mean age was 42.6 years
(16.0 to 84.6). There were 425 lower limb and 32 upper limb frames.
The mean duration of treatment was 25.7 weeks (1.6 to 85.3). According to NICE guidelines all the patients had at least one
risk factor for VTE, 246 had two, 172 had three and 31 had four
or more. One patient (0.23%) developed a pulmonary embolus after surgery
and was later found to have an inherited thrombophilia. There were
27 deaths, all unrelated to VTE. The cost of providing VTE prophylaxis according to NICE guidelines
in this group of patients would be £89 493.40 (£195.80 per patient)
even if the cheapest recommended medication was used. The rate of symptomatic VTE after Ilizarov surgery was low despite
using no pharmacological prophylaxis. This study leads us to question
whether NICE guidelines are applicable to these patients. Cite this article:
Over a 13-year period we studied all patients who underwent major hip and knee surgery and were diagnosed with objectively confirmed symptomatic venous thromboembolism, either deep venous thrombosis or non-fatal pulmonary embolism, within six months after surgery. Low-molecular-weight heparin had been given while the patients were in hospital. There were 5607 patients. The cumulative incidence of symptomatic venous thromboembolism was 2.7% (150 of 5607), of which 1.1% had developed pulmonary embolism, 1.5% had deep venous thrombosis and 0.6% had both. Patients presented with deep venous thrombosis at a median of 24 days and pulmonary embolism at 17 days after surgery for hip fracture. After total hip replacement, deep venous thrombosis and pulmonary embolism occurred at a median of 21 and 34 days respectively. After total knee replacement, the median time to the presentation of deep venous thrombosis and pulmonary embolism was 20 and 12 days respectively. The cumulative risk of venous thromboembolism lasted for up to three months after hip surgery and for one month after total knee replacement. Venous thromboembolism was diagnosed after discharge from hospital in 70% of patients who developed this complication. Despite hospital-based thromboprophylaxis, most cases of clinical venous thromboembolism occur after discharge and at different times according to the operation performed.
