Spontaneous infectious discitis in adults.

PURPOSE

In adults, discitis most frequently follows spinal surgery. We report 16 adult patients with spontaneously occurring infectious discitis and compare them with an additional 52 patients abstracted from the literature. Infecting organisms, predisposing factors, imaging modalities, and response to therapy are described.

PATIENTS AND METHODS

The medical records of adult patients treated for infectious discitis of a community hospital during the past 10 years were reviewed. Postoperative spine patients and patients with primary osteomyelitis were excluded. Sixteen patients were identified with spontaneous primary infection of the disc space. The particulars of comorbid conditions, infection organisms, site of culture, and response to antibiotic therapy were noted and compared to 52 additional cases of spontaneous discitis reported in the literature since 1980.

RESULTS

A wide variety of infecting organisms was identified as causing spontaneous discitis, in contrast to previous reports of both postoperative discitis and spontaneous discitis. Nine of 10 patients with positive disc cultures had negative blood cultures. Appropriate antibiotics were curative in all patients but 1, regardless of the duration of symptoms. Nuclear imaging, computed tomography, and magnetic resonance imaging were all useful, although the last appears to be the most sensitive and specific imaging modality for detecting discitis.

CONCLUSIONS

Spontaneous infectious discitis is an uncommon cause of low back pain in adults. Nevertheless, it should be considered in any patient with acute or subacute pain. Elevated acute-phase reactants with appropriate imaging modality suggest the diagnosis. given the wide variety of infecting organisms identified, culture of blood and/or disc for the specific causative organism is critical to successful treatment outcome.