SPONTANEOUS INFECTIOUS DISCITIS IN ADULTS

PURPOSE: In adults, discitis most frequently follows spinal surgery. W e report 16 adult patients with spontaneously occurring infectious dis citis and compare them with an additional 52 patients abstracted from the literature. Infecting organisms, predisposing factors, imaging mod alities, and response to therapy are described. PATIENTS AND METHODS: The medical records of adult patients treated for infectious discitis at a community hospital during the past 10 years were reviewed. Postop erative spine patients and patients with primary osteomyelitis were ex cluded. Sixteen patients were identified with spontaneous primary infe ction of the disc space. The particulars of comorbid conditions, infec ting organisms, site of culture, and response to antibiotic therapy we re noted and compared to 52 additional cases of spontaneous discitis r eported in the literature since 1980. RESULTS: A wide variety of infec ting organisms was identified as causing spontaneous discitis, in cont rast to previous reports of both postoperative discitis and spontaneou s discitis. Nine of 10 patients with positive disc cultures had negati ve blood cultures. Appropriate antibiotics were curative in all patien ts but 1, regardless of the duration of symptoms. Nuclear imaging, com puted tomography, and magnetic resonance imaging were all useful, alth ough the last appears to be the most sensitive and specific imaging mo dality for detecting discitis. CONCLUSIONS: Spontaneous infectious dis citis is an uncommon cause of low back pain in adults. Nevertheless, i t should be considered in any patient with acute or subacute pain. Ele vated acute-phase reactants with appropriate imaging modality suggest the diagnosis. Given the wide variety of infecting organisms identifie d, culture of blood and/or disc for the specific causative organism is critical to successful treatment outcome.