What does Spinal Infection refer to?
This term encompasses a number of clinical presentations including discitis, vertebral osteomyelitis and epidural abscess. The organisms that cause infection vary from common bacteria to rare fungal infection and the return of an old adversary, tuberculosis (TB).
The diagnosis can be difficult and it is not uncommon for it to be missed in the first few weeks of symptoms unless the clinician performs a careful history, physical exam and orders appropriate diagnostic investigations. Investigations aim to determine the extent of infection and isolate the organism. Treatment is directed at eradicating the infection, whilst preserving or restoring neurological function and ensuring that spinal stability is maintained and controlling pain.
Who needs surgery?
Surgery may be recommended to drain an abscess putting pressure on the nerves in the canal (epidural abscess) or if there is compromised spinal stability. When infection is allowed to progress unchecked then the process can destroy spinal bone, ligaments and discs and compromise stability. If stability is compromised then there is a risk of deformity, fracture and dislocation of the spine and consequent neurological injury to the spinal cord or nerve roots contained within the spine. The extent of damage done by the infection can be evaluated by clinical examination supplemented with X-ray, CT, and MRI.
The spine surgeon needs to determine if the spine is unstable or at risk of becoming unstable and may recommend surgery to not only drain infection but to also reconstruct and stabilise the spinal column. At surgery specimens can be sent for microbiological examination to determine the responsible organism and the appropriate antibiotic treatment. Antibiotic treatment may need to continue for some time to eradicate the infection.
Sometimes infection of the spine occurs after surgery or other procedures on the spine. If there are implants then it is often necessary to washout the wound and gain specimens for culture. Antibiotic therapy can be directed specifically at any organisms grown from cultures but may need to be prolonged to suppress the infection. In certain circumstances implants are removed if they are no longer required for spinal stability.