Non-pyogenic infections of the spine.

Subacute and chronic spondylodiscitis can be caused by a wide spectrum of infectious aetiologies including Mycobacterium tuberculosis, Brucella spp. and a variety of fungi including Aspergillus spp., Candida spp. and Cryptococcus neoformans. Knowledge of the local epidemiology and prior exposure might suggest the aetiology. Non-invasive diagnostic approaches, such as blood culture or antibody titres in the case of Brucella or antigen detection in the case of fungal infections, can be helpful in reaching the diagnosis. However, direct aspiration or tissue biopsy is usually necessary to identify the causative organism. Specimens are usually sent for pathology, special stains, cultures and, when indicated, molecular analysis. To minimise morbidity and mortality, antibiotic treatment should be initiated promptly directed against the suspected organism, and later adjusted according to the confirmed aetiology. Surgical treatment is reserved for recurrent infection, unstable spinal segment or marked kyphosis in the face of any neurological deficits and uncontrollable pain. Surgical approaches are dictated by the anatomic location of the offending lesion. Once medical treatment fails and surgery becomes warranted, we advocate the use of a two-stage surgical treatment for non-fixed kyphosis and a three-stage operation for fixed kyphosis.