We report an audit of 208 patients with a mean age of 39 years (16 to 65) attending the Orthopaedic Assessment Unit at the Wellington Hospital between January 2006 and December 2007 with an injury of the tendo Achillis requiring immobilisation in a cast. Information on assessment of venous thromboembolism (VTE) risk, prophylactic measures and VTE events for all patients was obtained from the medical records. A VTE risk factor was documented in the records of three (1%) patients. One of the 208 patients received aspirin prophylaxis; none received low molecular weight heparin. In all, 13 patients (6.3%, 95% confidence interval 3.4 to 10.5) developed symptomatic VTE during immobilisation in a cast, including six with a distal deep-vein thrombosis (DVT), four with a proximal DVT, and three with a confirmed pulmonary embolus. This incidence of symptomatic VTE is similar to that reported following elective hip replacement.

We propose that consideration is given to VTE prophylaxis during prolonged immobilisation of the lower limbs in a cast, to ensure that the same level of protection is provided as for patients undergoing elective hip replacement.

In three consecutive years 462 patients over the age of 60 years presented at Waikato Hospital, Hamilton, New Zealand, with a fracture of the proximal femur. Within two years, 11 (2.4%) returned with a fracture of the contralateral femur. If the effectiveness of any form of treatment aiming at reducing the incidence of contralateral fracture were subjected to a trial, a sample size of 5000, randomly distributed equally between treatment and placebo groups, would be needed for the trial to have a power of 80% to detect a reduction.