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Vertebral osteomyelitis in northern Spain. Report of 62 cases

J. Belzunegui, N. Del Val¹, J.J. Intxausti, J.R. De Dios, R. Queiro, C. González, V. Rodríguez-Valverde¹, M. Figueroa

Rheumatology Unit, Hospital N.S. de Aránzazu, San Sebastián; ¹Rheumatology Unit, Hospital Marqués de Valdecilla, Santander, Spain.

ABSTRACT
Objective
The records of 62 patients with clinical and radiographic evidence of vertebral osteomyelitis and positive bacteriological diagnosis, seen between 1979 and 1996, were reviewed in order to gather data on the epidemiology and the clinical pattern displayed by patients with this condition in northern Spain.

Results
Staphylococcus aureus (15 cases), Mycobacterium tuberculosis (15 cases) and Brucella melitensis (13 cases) were the microorganisms most frequently found in our patient series. After improvement of the sanitary and hygienic control of food products, the role of Brucella melitensis is decreasing as a causative agent (only 3 cases in the last 6 years). Stapylococcus epidermidis, present in 4 cases (6.6%), should be suspected in elderly patients with previous intravenous cannulations (3 of 4 cases).
The most frequent risk factors were alcoholism (7 cases), chronic hepatic disease (7 cases), diabetes (6 cases) and previous surgery (6 cases). Delay in diagnosis was high (the mean number of days between the onset of symptoms and diagnosis was 125). The lumbar region was the most commonly affected site. Neurologic involvement was present in 10 patients on admission (16%). ESR was > 50 mm/hr in a high number of cases. Blood cultures were found to be the most valuable routine test. Plain x-rays were normal in 10 patients (16%); in 6 of them Staphylococcus aureus was the responsible organism. Other imaging modalities showed a high sensitivity. Surgical drainage was necessary in 12 individuals (in 7 due to Mycobacterium tuberculosis). Outcome was good in the majority of cases: only 2 patients with associated endocarditis died. Neurologic sequelae were present in another 3 patients.

Conclusion
Vertebral osteomyelitis can be caused by a variety of pathogens. Therefore, bacteriological studies are necessary to establish the etiologic diagnosis and determine the specific antimicrobial treatment required.

Key words
Vertebral osteomyelitis, Staphylococcus aureus, Mycobacterium tuberculosis, Brucella melitensis.

Please address correspondence and reprint requests to: J. Belzunegui, MD, Rheumatology Unit, Hospital N.S. de Aránzazu, 20014 San Sebastián, Spain.