CLINICAL HISTORY This eight-year-old boy presented with pain in his distal medial thigh, near the knee, which had developed gradually over the course of several days. His father had initially believed it to be a minor problem and treated his son with paracetamol. But when his son was unable to weight bear he sought medical […]
CLINICAL HISTORY
This eight-year-old boy presented with pain in his distal medial thigh, near the knee, which had developed gradually over the course of several days. His father had initially believed it to be a minor problem and treated his son with paracetamol. But when his son was unable to weight bear he sought medical advice.
Shortly before the MRI, the boy began to experience fevers. There had been no history of rigors, night sweats, cachexia or anorexia to that point. On physical examination, no redness or swelling was detected, although localised tenderness at the distal medial thigh was present.
IMAGING FINDINGS
There was a normal radiograph.
On MRI, in the distal medial femoral metaphysis, abnormal low signal in the marrow on T1 weighted sequences was accompanied by marrow oedema on T2 fat-saturated sequences, as well as oedema in the medial growth plate and in the adjacent periosteum.
There was no bony destruction or soft tissue mass to suggest a malignancy such as osteosarcoma or Ewing’s sarcoma.
CLINICAL RELEVANCE AND MANAGEMENT
This has the typical clinical history and appearance of childhood osteomyelitis. Typically, paediatric osteomyelitis is due to haematogenous spread of bacteria.
Infection tends to occur in the metaphyseal ends of the long bones because of the sluggish circulation in the metaphyseal capillary loops.
The patient was treated with intravenous antibiotics and responded well.
Dr Sebastian Fung is MSK Radiologist at St Vincent’s Clinic Medical Imaging and Nuclear Medicine in Sydney
