The spine is made up of bones called vertebrae which surround and protect the spinal cord. These are separated by intervertebral disks which provide cushioning between the vertebral bones. A spinal infection may affect any part of your spine, i.e. the vertebral column, intervertebral disks or the soft tissues surrounding the spine.
Symptoms of Spinal Infection
Spinal infections are characterised by back or neck pain, depending on the site of the infection, which gradually becomes severe and is not relieved by rest or medications. You may develop a fever, stiffness or headache. There may be increased wound redness or drainage if recent spine surgery was performed. As the disease progresses, the vertebral bones undergo damage which can lead to neurological symptoms such as numbness, tingling or weakness in the arms or legs.
Causes of Spinal Infection
Spinal infections can be caused by bacteria or fungi which reach the spine through the bloodstream. The most common causative agents for spinal infections are species of bacteria called Staphylococcus aureus and Escherichia coli. A spinal infection may develop following spine surgery or pelvic surgery as the veins in the lower spine arise through the pelvis. In some cases, intravenous drug abuse may also lead to spinal infection.
Diagnosis of Spinal Infections
Diagnosis for a spinal infection may be time-consuming if symptoms are not definitive as your doctor will have to carefully rule out other conditions. Diagnostic tests are performed which include blood testing for erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels. High values of CRP and ESR indicate inflammation which occurs during a spine infection. X-ray imaging, computed tomography scan (CT or CAT scan) or magnetic resonance imaging (MRI) may be recommended. Your doctor may also order a computed tomography-guided biopsy sampling of the vertebra or disk space to identify the causative agent. A blood culture may be performed if you have developed a fever.
Treatment of Spinal Infections
The first line of treatment involves intravenous administration of antibiotic or antifungal therapy. Treatment duration may be six to eight weeks or more depending on your recovery.
Surgery may be recommended under the following circumstances if:
- Your condition does not improve or the infection does not resolve with a conservative approach
- A large area of vertebral bone is affected making the spine unstable
- You have significant neurological symptoms
The objectives of surgical treatment for a spinal infection include:
- Debridement: cleansing and removal of the infected spine tissue/bone
- Ensuring adequate blood flow to the infected tissue to promote healing
- Restoring and maintaining spinal stability
- Restricting the degree of neurological impairment
Procedure for Debridement of Spinal Infection
The procedure is performed under general anaesthesia and antibiotic cover. Your surgeon would have marked the region of infection based on your diagnostic reports. The spine may be approached from the front or back depending on the region of the infection. The underlying infected vertebral bones and spine tissue are accessed. Purulent material and tissue causing nerve compression are removed and the area is irrigated with an antibiotic solution. If the spine is unstable after debridement, suitable procedures are performed to restore stability. The incision is then closed, and a surgical drain is left in place.
You will continue to receive antibiotics in the postoperative period. The drainage tube is removed when there is minimal drainage of fluid. You may be advised to wear a brace to support the spine as it heals. You will usually receive a long course of oral antibiotics.
Risks and Complications
As with any surgery, debridement of a spinal infection may also have some risks that include:
- Spinal cord injury
- Damage to the surrounding organs such as the heart, lungs, kidney, ureter and bowel
- Increased blood loss
- Side effects associated with anaesthesia