Osteomyelitis: Vertebral Infection
and Michael J. Young, M.D.
Vertebral osteomyelitis is infection in the vertebral body itself. It may be caused by either a bacteria or a fungus. Bacterial or pyogenic vertebral osteomyelitis is more common. Its presentation is different than a disc space infection. It may represent infection elsewhere in the body that has seeded the spine through the blood stream.
These patients are systemically ill, exhibiting increased temperature, white blood cell and erythrocyte sedimentation rate. The average time from onset of symptoms to definitive diagnosis has been reported to range from 8 weeks to 3 months. The onset is usually insidious, with back pain the most common symptom. The pain is localized at first to the level of the involved area, with a gradual increase in intensity. The pain eventually becomes so severe it is not relieved by complete bedrest.
Usually neurologic signs are not present until late in the disease course when there can be destruction and collapse of the vertebral body. Other symptoms variably present include chills, weight loss, dysuria, photophobia, and drainage from a wound or incision if there has been prior surgery.
The causative agent is usually Staphylococcus aureus. Long term antibiotic therapy is required, usually six weeks of intravenous antibiotics sometimes followed by oral antibiotics for another six week period. Surgery may be indicated, particularly when ongoing vertebral destruction is identified. Although rare, typical diseases such as tuberculosis of the spine should be considered when faced with spinal infections. This is more common in underdeveloped countries.
Osteomyelitis on x-ray.