Pyogenic osteomyelitis of the vertebral arch in children.

Vertebral infection represents 2% to 4% of all cases of osteomyelitis in children. Extension of vertebral osteomyelitis into the vertebral arch is rare; and exclusive pyogenic involvement is exceedingly rare, especially in children. A review of the literature revealed less than 25 combined cases, most of them reported in the beginning of the 20th century without cross-sectional imaging. The unusual location creates difficulties in distinguishing vertebral osteomyelitis from neoplasm and arthritic conditions. We present 2 cases of infection of the posterior vertebral elements. Most useful in identifying the presence and extent of infection were a sudden onset of nonspecific back pain, elevated inflammatory parameters, and magnetic resonance imaging. Antibiotic therapy with or without surgical intervention provided successful management. With the recurrence observed in 1 child, the most optimal treatment of this condition might still be unknown.