[Osteoarticular involvement in parasitic diseases: bone echinococcosis]

Hydatid disease is the most common human disease caused by helminths, but primary skeletal involvement is uncommon. Diagnosis is usually obtained late after considerable extension, half of which concerns the spine. The dissemination mode leads to local malignancy with severe prognosis. Medical imaging is essential. Plain x-ray findings are polymorphous and nonspecific, but computed tomography and magnetic resonance imaging are particularly useful for exhaustive pretherapeutic assessment of extension and for patient follow-up.