Haematogenous Spondylodiscitis

Pyogenic vertebral spondylodiscitis (PVO) is group of infectious diseases that involves the intervertebral disc, vertebral bodies and, occasionally, other structures near the spine. Haematogenous spread is the most frequent pathway for vertebral osteomyelitis. Its frequency has risen in the past years because of the increase in elderly population, immunosuppression conditions and chronic illnesses, among other factors. It requires a multidisciplinary approach which includes spine surgeons, clinical physicians, radiologists and infectious disease specialists. The lumbar spine is the most often involved spinal segment, and the most frequent symptom is axial pain. Neurological impairment can be observed if there is extension of the infection into the epidural space or neural foramen. Magnetic resonance (MR) of the spine is the gold standard for imaging diagnosis. Usually, initial blood work-up shows increased white blood cell count and inflammatory markers such as erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). Blood cultures should be obtained as well as a CT-guided percutaneous needle aspiration biopsy to identify the microorganism and obtain histological material. Nevertheless, the sensitivity of these procedures varies from 50% to 60%. Staphylococcus aureus is the most common germ involved. Broad-spectrum antibiotic therapy is suggested as soon as the disc biopsy and blood cultures are undertaken. On many occasions, antibiotics should be started before isolating the pathogen if cultures are negative and clinical picture is highly suggestive of PVO and if the patient is septic or his/her clinical or neurological condition is deteriorating. Medical management with antibiotics is the mainstay of treatment of most spinal infections. Undertaking surgery for PVO can provide rapid decompression of nerve roots and spinal cord as well as stabilization when there is neurological deficit, instability or deformity.