Spinal infections can be classified by the anatomical location involved: the vertebral column, intervertebral disc space, the spinal canal and adjacent soft tissues.
- Spondylitis – Inflammation of one or more vertebrae.
- Discitis – inflammation of one or more intervertebral disc spaces.
Spondylodiscitis can be defined as a primary infection of the spine (accompanied by destruction) of the intervertebral disc (discitis), with secondary infections of the vertebrae (spondylitis).
What are its Causes? Who are prone to infections?
Spondylodiscitis is caused by microorganisms (agents ) which infect the humans ( host) and produce infections under ( environment).
- Agents – microorganisms producing infections can be pyogenic (bacterial- staphylococcus, Ecoli etc)- pyogenic spondylodiscitis, mycobacterial/tuberculosis Spondylodiscitis- TB spine/ Kochs’ spine/ potts’ disease fungal Spondylodiscitis.
- Host factors – there are certain predisposing factors in us that make us prone for infections. These includes:
- Diabetes mellitus
- Advanced Age.
- Infection: urinary tract infection/ Respiratory tract infection/ skin infections.
- Impaired immunocompetence ( Cancer / chemotherapy, human immunodeficiency virus infections, or chronic alcoholism).
- Renal failure/ Dialysis.
- Environment factors – almost everyone is exposed to microorganisms around us yet not all develop infections. The rate of infections is 1-5%.
These microorganisms produce infections in us under certain circumstances only such as:
- Low immunity.
What are the symptoms?
- Symptoms associated with spinal infections will depend on the location and severity of the infection. It may cause any of the following symptoms:
- Back pain – disabling pain in severe cases restricting activities and altering sleep)
- Unexplained weight loss
- Swelling, redness, and warmth around the area of infection
- Pain on touching around the area of infection
- Rarely the infection may affect the spinal canal and produce pus around the spinal cord called as abscess. The Pus presses on the spinal cord or nerves and may produce additional symptoms:
- Severe back pain with fever and local tenderness in the spinal column.
- Pain going down in the legs from the back. ( radiating pain- nerve root pain).
- Weakness/ difficulty in moving the legs or hand.
- Difficulty in passing urine/ stool.
How is diagnosed? What are the tests?
- Specific laboratory tests can be useful in helping to diagnose a spinal infection which may include:
- Complete blood Count (CBC)
- Erythrocyte sedimentation rate (ESR)
- C-reactive protein (CRP).
- Both ESR and CRP tests are often good indicators as to whether any inflammation is present in the body (the higher the level, the more likely it is that inflammation is present). These tests alone however, are limited, and other diagnostic tools are usually required.
- Imaging studies are necessary to pinpoint the location and extent of a lesion. The choice of specific imaging techniques varies slightly depending on the location of the infection which may include:
- Plain X-rays.
- CT- Scans.
- MRI with or without contrast.
- The degree of bone destruction is best imaged by computed tomography scan (CT scan), whereas soft tissue, pus, neural structure compression is best defined by magnetic resonance imaging (MRI).
- Biopsy: Once the diagnosis is confirmed by blood and imaging studies, identification of the organism is essential, and this can be accomplished through computed tomography-guided biopsy sampling of the vertebra or disc space.
How is it treated? Does it require surgery?
- Management of spinal infection is essentially a medical management requiring oral medications or long-term intravenous I.V. antibiotic or antifungal therapy with hospitalization if neededdepending upon the severity of infections and the condition of the patient.
- Restricted mobilization or bed rest may be recommended when there is significant pain or the potential for spine instability. The type of medication is determined on a case-by-case basis depending on the organisms, patient’s specific circumstances, including his or her age.
- Surgery is advised only to tackle a complication that has occurred due the infection. It may be indicated when any of the following situations are present:
- Significant bone involvement- making the spinal column unstable.
- Neurological deficits- difficulty/ inability to move legs or hands/ paralysis.
- Difficulty in passing urine/ stool.
- Numbness around the urinary region.
- Progression of infection despite antibiotics coverage.
- Failure of needle biopsy to obtain needed cultures.
- Failure of intravenous antibiotics alone to eradicate the infection.
The primary goals of surgery are to :
- Debride (clean and remove) the infected tissue.
- Enable the infected tissue to receive adequate blood flow to help promote healing
- Maintain or restore spinal stability
- Remove the pressure (decompress) the spinal cord or nerve roots and limit the degree of neurological impairment.
In certain cases, the surgeon may need to perform a spinal fusion to ensure the spinal column is stable after surgery. The Intravenous or oral medication will still be needed to continue for the required time.