Spondylodiscitis is a spinal infection, defined as an infection of the intervertebral disc and the adjacent vertebral body.
Vertebral osteomyelitis is often associated with discitis, which may be grouped together under the term spondylodiscitis.
Although rare, spondylodiscitis is the main manifestation of haematogenous osteomyelitis in patients aged over 50 years 1) and represents 3–5% of all cases of osteomyelitis 2)
Infectious spondylodiscitis has doubled in incidence during the past 10-20 years to approximately six cases per 100,000 person-years in Scandinavia and other regions of the world 3) 4)
In recent years, the incidence of infectious spondylodiscitis has increased due to vast improvements in medical care and prolonged life expectancies. The condition is associated with advanced age, intravenous drug use, immunocompromised status, and significant medical comorbidities 5).
It represents, at the most, 2-4% of osteoarticular infections in children and its clinical presentation is often insidious.
Non-specific spondylodiscitis in children is caused by haematogenous spread of pathogens. Staphylococcus aureus is the most frequently detected bacterium. The clinical signs are unspecific and an Magnetic Resonance Imaging of the spine is the standard radiological procedure to detect spondylodiscitis. In general, the treatment is conservative and includes an antibiotic therapy as well an immobilization of the spine. In endemic areas of the world, specific spondylodiscitis is more common and is caused by Mycobacterium tuberculosis or Brucellae. The treatment is also conservative. For all entities of spondylodiscitis in children, a surgical intervention is only necessary in the case of severe deformities due to the infection or in the case of neurological symptoms.
Elevated infectious laboratory values and back pain or other unspecific symptoms can indicate spondylodiscitis in children. MRI of the spine is necessary to rule out spondylodiscitis 6).
Infection of the nucleus pulposus. May start in the cartilaginous endplate and spread to the disc and vertebral body (VB). Similar to vertebral osteomyelitis, except osteomyelitis primarily involves the VB and spreads secondarily to the disc space.
Identifying the causative pathogen is the key to treatment. CT guided biopsy and drainage are the standard procedure for identifying causative pathogens. However, the pathogen-identification rate varies among studies 7) 8) 9)
Clinicians must maintain a high index of suspicion for discitis in patients who undergo discogram.
A meta-analysis, with an overall pooled sample size of 10,954 patients from 21 studies, found that the pooled mortality among the early surgery patient subgroup was 8% versus 13% for patients treated conservatively. The mean proportion of relapse/failure among the early surgery subgroup was 15% versus 21% for the conservative treatment subgroup. Further, it concluded that early surgical treatment, when compared to conservative management, is associated with a 40% and 39% risk reduction in relapse/failure rate and mortality rate, respectively, and a 7.75 days per patient reduction in length of hospital stay (p < 0.01). The meta-analysis demonstrated that early surgical intervention consistently significantly outperforms conservative management in relapse/failure and mortality rates, and length of stay, in patients with pyogenic spondylodiscitis 10)