Bone Abstracts

Background: Chronic recurrent multifocal osteomyelitis (CRMO) is an auto-inflammatory bone disorder that has been difficult to diagnose in the past. Diagnosis used to depend on bone biopsy but can now be made with whole-body MRI scan.

Presenting problem: A 9-year-old healthy girl had a 2-year history of pain, swelling, redness and heat in her right foot following a fall from bars in the park. She had an X-ray of her foot on the day of injury which was reported to be normal (Fig. 1).

The pain and swelling persisted and she had a repeat X-ray (Fig. 2), MRI scan, blood tests and a bone biopsy at her local hospital, which ruled out malignancy. After a year her foot was still swollen and painful and she was unable to walk far.

Her right middle metatarsal was inflamed and tender on palpation, and she walked with a limp. Blood tests showed raised ESR and X-ray of right foot showed periosteal reaction (Fig. 3). A month later X-ray showed more expansion of the lesion encompassing the whole of the diaphysis. She had a CT scan, a second biopsy, chest X-ray, and skin tests to rule out tuberculosis.

Clinical management: She was referred to the paediatric metabolic bone clinic where a whole-body MRI scan was requested and showed signs of CRMO.

She was treated with i.v. pamidronate 3 monthly for three cycles, which led to a dramatic improvement in symptoms, clinical signs and radiological appearance (Fig. 4).

Discussion: This case shows that whole-body MRI scan can make the diagnosis of CRMO and that pamidronate treatment can be dramatically effective.

Disclosure: The authors declared no competing interests.

Figures 1-4