Spontaneous disc space infections in adults.

BACKGROUND

Spontaneous discitis typically affects children; much less is known about the disease in adults. We examined the clinical characteristics and the role of surgery in spontaneous infectious discitis in adults.

METHODS

Twenty-nine consecutive adult patients (16 men, 13 women) with spontaneous infectious discitis were treated by a single surgeon (MJE) over a 5-year period. These patients were compared to 19 consecutive patients with postoperative discitis over the same time period. Mean follow-up was 2.4 years.

RESULTS

The average age of patients with spontaneous discitis was 69.0 years. Eleven of these patients (38%) were diabetic and 9 (31%) had a known concurrent infection. Infections occurred at cervical (10%), thoracic (34%), and lumbar interspaces (59%), and at multiple disc spaces in eight cases (28%). Ten patients (34%) had an elevated serum leukocyte count and 21 patients (72%) had an elevated erythrocyte sedimentation rate. While Gram-positive infection was most common, a broad spectrum of microbes was isolated. All patients were treated with i.v. antibiotics for a mean duration of 6 weeks. Four patients required surgical fusion; the rest were treated with external immobilization. At follow-up, 21 patients (72%) were symptom-free, 3 patients (10%) had ongoing disease, and 5 patients (17%) had died of unrelated causes. Compared to patients with postoperative discitis treated over the same time period, spontaneous discitis in adults affected older patients and required a broader spectrum of antibiotic coverage. Outcomes were similar between the two groups.

CONCLUSIONS

While spontaneous discitis has predominantly been reported in children, the disease also affects older adults. Spontaneous discitis in adults is associated with advanced age, diabetes mellitus, and systemic infection. Elevated serum leukocyte count lacks diagnostic sensitivity. A high cure rate is achieved with antibiotics and external immobilization. Surgical treatment is rarely required.