The aetiology of Panner’s disease is unknown. Thrombophilic states have been implicated in Perthes’ disease but remain controversial. The relationship, if any, between thrombophilia and Panner’s disease is not known.

A 7 year old boy presented with pain and restriction of motion in one elbow with no history of trauma. Radiographs confirmed Panner’s disease. A thrombophilia screen showed an abnormal activated protein C resistance test consistent with the presence of Factor V Leiden in the heterozygous state. Thrombophilia may predispose to thrombotic venous occlusion in bone leading to intramedullary hypertension, anoxia and avascular necrosis. This may explain the aetiology of some cases of Panner’s disease. Resistance to activated protein C is a common heritable thrombophilia. The incidence in the UK is around 1.75%. It is caused by a CGA to CAA substitution at position 1691 of the Factor V Leiden gene. This blocks the binding of activated protein C to prothrombotic Factor V producing thrombophilia. Factor V Leiden carriers are three times more likely to experience clinical venous thrombosis than non-carriers. Whilst this risk does not warrant lifelong anticoagulation, thromboembolic events are more likely to cause problems than Panner’s disease which is essentially self-limiting. Affected patients should avoid other risk factors such as smoking or the combined contraceptive pill.

As Factor V Leiden is common in our population, its presence in this patient may be incidental. Thrombophilia screening should be considered for patients with Panner’s disease. This enables appropriate counselling if a thrombophilic condition is found.