Introduction
Spinal infections can cause various symptoms depending on the type of spinal infection. The infectious agents that cause spinal infections can affect the spinal discs, vertebrae, spinal canal, meninges, and even the spinal cord. When the pathogens infect the intervertebral discs, the condition is called discitis (disc inflammation). When the bones of the spine are attacked, it is called osteomyelitis. Usually, these infections spread to the spinal region through the bloodstream. Common bacteria like Escherichia coli or Staphylococcus can enter the bloodstream following surgery or drug abuse.
What Are the Various Types of Spinal Infections?
Spinal infections can be classified according to the anatomical locations, namely the intervertebral disc space, vertebral column, spinal canal, and the neighboring soft tissues. The following are the various types of spinal infections:
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Vertebral Osteomyelitis: These infections commonly occur in the lumbar spine and can cause fever, pain in the arm or leg, muscle spasms, weight loss, and problems with using the hands or walking.
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Spinal Epidural Abscess: These infections most commonly manifest in the lumbar region and can cause back pain, weakness, skin boils, spine tenderness, arm or leg pain, and bladder, bowel, and abdominal issues.
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Discitis: It is a rare infection that can occur on its own or following surgery. Symptoms include fever and chills, pain with spine movement, and radiating pain in various body parts.
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Meningitis: Meningitis results in swelling in the tissues surrounding the brain and spine. This infection has the potential to spread rapidly and can result in serious complications if not treated appropriately.
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Spinal Subdural Empyema: This kind of infection is very rare and usually originates from an infection in another region. It can cause arm or leg pain and fever.
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Spinal Cord Abscess: Spinal cord abscess is a very rare infection and is caused internally in the spine. It can cause back pain, fever, and a deterioration in spine function.
Who Is at Risk of Developing Spine Infections?
The following are at risk of developing spine infections:
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Diabetic individuals.
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Organ transplantation.
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Malnutrition.
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Those with renal failure or those who have undergone hemodialysis.
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Immunosuppression is caused by cancer, HIV (human immunodeficiency virus), alcohol, or chronic use of steroids.
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Previous spinal surgeries or any invasive procedures.
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Elderly people with no other risk factors.
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Infectious endocarditis (a bacterial infection that manifests when bacteria enters the bloodstream and settles in the heart valve, heart lining, or a blood vessel).
What Are the Causes of Spinal Infections?
The causes of spinal infections are as follows:
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Spinal infections can occur due to either a bacterial or fungal infection in another part of the body that has been transported to the spine through the bloodstream. Spinal infections are most commonly caused by microorganisms such as Staphylococcus aureus and Escherichia coli.
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Spinal infections can occur after a urological procedure since the veins in the lower spine come up through the pelvis. The most common region in the spine that gets affected is the lumbar region. Intravenous drug abusers are more susceptible to infections that affect the cervical region.
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Recent dental procedures can elevate the risk of spine infections as the bacteria may enter the bloodstream during the procedure and can travel to the spine.
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Intervertebral disc space infections usually originate in one of the contiguous endplates, and the infection in the disc occurs secondarily. However, such infections in children remain a controversy. Most biopsies and cultures in children are negative, due to which experts believe that childhood discitis may not be an infectious condition but rather may occur due to the partial dislocation of the epiphysis (the growth region near the end of a bone) as a result of a flexion injury.
What Are the Common Warning Signs of a Spinal Infection?
Some of the common warning signs of a spinal infection include:
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Neck stiffness or lower back pain.
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Loss of mobility or range of motion.
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Chills, fever, or loss of appetite.
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Back pain that worsens at night or does not resolve even after taking rest.
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Surgical wounds with pus discharge or those that do not heal.
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Redness or warmth on the skin’s surface or at the site of surgical incisions.
How Can Spinal Infections Be Diagnosed?
Spinal infections can be diagnosed through imaging studies and laboratory investigations. Early stages of infection can be diagnosed through X-rays. Soft tissues like spinal discs cannot be viewed on X-rays, but X-rays can show bone deterioration and loss of disc height. Loss of disc height can be detected by a decreased amount of space between the two vertebrae. An MRI (magnetic resonance imaging) may be suggested to view the soft tissues and to assess bone health.
Laboratory investigations to diagnose spinal infections include examining markers for inflammation or determining the white blood cell count. The markers of inflammation are specifically known as the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). These indicators will be abnormally high in 85 percent of all cases of spinal infection. A blood culture may also be suggested by the physician to identify the specific pathogen that causes pain. Blood cultures can, however, successfully detect pathogens in less than 50 percent of spinal infection cases.
How Can Spinal Infections Be Treated?
Spinal infections can be treated in the following ways:
Nonsurgical Treatment: Spinal infections usually require long-term intravenous antibiotics or antifungal therapy, and the patient might need an extended stay at the hospital. Immobilization may be suggested by the physician when there is immense pain or if there are chances for spinal instability. If the patient is neurologically normal and if the spinal column is structurally stable, antibiotic treatment should be given after properly identifying the organism that has caused the infection. Antimicrobial therapy may usually be recommended for a minimum of six to eight weeks. The type of medication is decided based on the patient’s circumstances and age.
Surgical Treatment: Nonsurgical treatment should be considered the first treatment option if patients have minimal or no neurological issues and if the morbidity and mortality rate of surgical intervention is high. Surgery is indicated in the following circumstances:
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Neurological deficits.
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Significant bone destruction resulting in spinal instability.
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Failure of intravenous antibiotics alone to clear the infection.
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Sepsis with clinical toxicity is caused by an abscess that is not responsive to antibiotics.
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Failure of needle biopsy to obtain required cultures.
The major goals of surgery are:
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Clean and remove (debridement) the infected tissue.
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Allow the infected tissue to receive the necessary blood flow to enhance healing.
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Restore function or reduce the degree of neurological impairment.
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Restore spinal ability through instrumentation to fuse the insatiable spine.
Once it is fixed that the patient requires surgery, imaging tools like X-rays, CT (computed tomography) scans, or MRI (magnetic resonance imaging) can further aid in pinpointing the level at which the surgery needs to be performed.
Conclusion
An infectious disease that affects the intervertebral disk, vertebral body, or adjacent paraspinal tissue is called spinal infection. These types of infections account for two to seven percent of all musculoskeletal infections. Treatment with IV (intravenous) antibiotics for a minimum of eight weeks is the most common treatment option. Since the spinal discs have limited blood supply, it takes some time for antibiotics and the body’s immune cells to target the infection and start fighting against it. Apart from antibiotics, patients may require a back brace to keep the spine stable. In advanced cases of spinal infection, spinal surgery may be necessary to treat the infection and relieve nerve compression.
