Abstract

Background: Bacterial spondylodiscitis is rarely caused by anaerobic organisms. We describe two patients with lumbar vertebral osteomyelitis and discitis caused by anaerobic bacteria, including an unusual occurrence after an endodontic procedure, and review the salient clinical features and outcomes of 31 previously reported cases.

Methods: Case reports and review of the literature.

Results: Median age at presentation was 65 years, with a male-to-female ratio of 2:1. The most common presenting symptoms were back pain, fever, and neurologic deficits. The lumbar spine was most frequently involved (43%); an equal number of cases involved contiguous extension or hematogenous spread. Causative anaerobes were recovered from disk space or vertebrae (13), blood (4), and/or soft tissue abscess and included Bacteroidesspecies (12), Propionibacterium acnes (7), Peptococcus species (4), Peptostreptococcusspecies and Clostridium species (3 each), Corynebacterium diphtheroides andFusobacterium species (2 each), and unspecified anaerobes (3).

Conclusions: Apart from specific antibiotic selection, medical treatment and outcomes for anaerobic spondylodiscitis are similar to those for aerobic vertebral disk infection.

Key Points

* The most frequent pathogenetic organisms isolated in anaerobic spondylodiscitis includeBacteroides species, Propionibacterium acnes, and Peptococcus species.

* The most common sites of vertebral involvement, in decreasing order of incidence, include lumbar, sacrococcygeal, cervical, and thoracic regions.

* Anaerobic spondylodiscitis typically presents with back pain, fever, and motor neurologic deficits.

* Of all the radiographic modalities, magnetic resonance imaging has the most diagnostic accuracy.

* Anaerobic spondylodiscitis is generally treated in the same fashion as aerobic infection, with 4 weeks or more of parenteral antibiotic therapy.