[Blunt force injuries due to martial arts in children--a diagnostic problem? Delayed diagnosis of an infected...

Blunt force injuries in martial arts occur frequently but isolated hematoma of muscles in the extremities is rare. Even minor trauma of the lower extremities due to throwing techniques in judo and other forms of Asian martial arts can lead to major pathologies.

A 9-year-old girl presented with an unclear swelling and soreness of the calf muscle. The patient could not remember an obvious traumatic event. She was admitted 4 days later because of increased swelling, pain and erythema. The parents reported a minor trauma at judo training 1 week ago. Further investigation was performed with MRI and confirmed a massive hematoma much greater than previously shown by sonography.

Histologic and microbiologic evaluation demonstrated florid inflammation and proof of Staphylococcus aureus was found intra-operatively.

The diagnosis of blunt force injuries due to martial arts is difficult in childhood because often children do not remember a traumatic event. Therefore, it is important to obtain a thorough history from caregivers. Because sonography depends highly on the experience of the investigator MRI is considered to be a better diagnostic modality to diagnose and guide treatment in this age group.