Oral Cavity Infection: An Underestimated Source of Pyogenic Spondylodiscitis?

The incidence of pyogenic spondylodiscitis is increasing; however, the source of infection often remains obscure. We analyzed predisposing factors, pathogens, and outcome of patients undergoing surgical and/or conservative treatment of spondylodiscitis with a focus on the diagnostic work-up including a comprehensive maxillofacial assessment.

The analysis of prognostic factors comprised comorbidities, nicotine dependence, symptom duration, and oral cavity peculiarities. After a standardized diagnostic work-up, a detailed examination of the oral cavity was also performed. The outcome analysis included assessment of the patients' clinical status.

Forty-one patients with pyogenic spondylodiscitis were investigated of whom 24% had undergone spinal surgery within 4 weeks before the infection. A total of 29% of patients were found to have a concomitant bacterial oral cavity disease, and in 22% the definitive source of infection remained unidentified. Among the 12 patients with oral cavity infections, 10 patients had periodontitis; 8, root canal pathologies; 6, periapical lesions, and another 8 patients, caries. In 25% of these patients, typical oral cavity pathogens were found in the intervertebral disk. The prevalence of oral cavity infections was associated with a history of nicotine dependence (p = 0.003). All other analyzed comorbidities did not differ compared with patients without an oral cavity focus.

Oral cavity infections appear to be a frequent source of pyogenic spondylodiscitis, with smoking its most relevant associated risk factor. In case of an unidentified infection focus, a detailed diagnostic work-up including a mandatory maxillofacial assessment is strongly recommended.