LAUSR

The 1611C > A variant in thrombomodulin is associated with a very rare autosomal dominant bleeding disorder [1, 2]. This mutation leads to the synthesis of a truncated TM which has lost the last three amino acids of the transmembrane domain and the cytoplasmic tail [3, 4]. To date, no homozygous cases have been reported, while heterozygous individuals are prone to severe bleeding episodes, particularly during and after surgery or following trauma [1, 2]. Patients carrying this variant have a normal coagulation profile, including APTT, PT and fibrinogen levels. The only observed abnormality is an elevated residual factor II level, while all other coagulation factors and platelet counts remain within normal ranges. The condition is characterised by markedly elevated plasma-free thrombomodulin levels [1, 2]. There is little clinical experience in the management of surgery in patients with this mutation and excessive circulating thrombomodulin, which leads to explosive-activated protein C generation [1, 2]. This in turn dramatically inhibits activated Factors VIII and V and ultimately severely impairs thrombin generation. We present a case of high-risk orthopaedic surgery involving the excision of a large osteochondroma of the distal femur