The Gunnar-Thevathasan haemorrhagic crescent sign

• Eponymous signs and syndromes abound..
• This one can be diagnosed in the ED when the history of soft tissue injury of the patient's knee is followed by the appearance of a haemorrhagic crescent under the ipsilateral malleoli days to weeks later. The patient may be concerned that they have a DVT because of calf swelling or pain, but this is NOT a DVT.
• First described in 1976, the haemorrhagic crescent sign of acute synovial rupture (named after G. Kraag and E.M.Thevathasan) develops secondary to haemorrhage caused by an acute synovial rupture of the knee, the ecchymosis eventually dissecting downward through the tissues and settling below the malleoli.
• The history of knee trauma may be relatively minor.
• click the link to more clinical images:

http://www.broadcomplex.com.au/cases/can-you-diagnose-this