Osteomyelitis: Vertebral Infection
Vertebral osteomyelitis is the most common form of vertebral (spinal bone) infection, though it’s a relatively rare disease. Vertebral osteomyelitis affects an estimated 26,170 to 65,400 people each year, and it can cause a wide range of symptoms—from back pain to significant neurological problems (like difficulty walking).
The likelihood of developing vertebral osteomyelitis increases as you age. This infection most commonly occurs in adults in their 60s and 70s, and males are more susceptible to the disease than women.
The importance of early diagnosis and treatment of vertebral osteomyelitis cannot be overstated, as delaying treatment may result in permanent paralysis.
Vertebral Osteomyelitis Causes and Risk Factors
Vertebral osteomyelitis can be caused by a variety of sources—from spinal trauma, infections in surrounding areas, and most commonly by bacteria in the bloodstream that settles in an intervertebral disc; the structure that acts as a cushion between the vertebrae in the spine.
Acute osteomyelitis is usually caused by the Staphylococcus aureus bacteria, which can enter the bloodstream through a wound or contaminated needle. Chronic osteomyelitis can result from tuberculosis, AIDS, and other conditions that affect the immune system.
Certain people are more at risk of developing vertebral osteomyelitis, and most people who have this disease have at least one risk factor. Outside of age, the most common risk factor is having diabetes, but people with the following conditions also have a higher likelihood of this infection:
- Cirrhosis (scarring of the liver)
- Chronic kidney disease
- Intravenous drug use
- Rheumatoid arthritis
- Spinal fracture
- Recent spinal procedure
Vertebral Osteomyelitis Symptoms
Vertebral osteomyelitis may be overlooked by physicians because of its rarity. Plus, its primary symptom—severe back pain—is often attributed to another more common spinal issue. Back pain due to this infection often starts gradually, and it gets worse at night.
Outside of severe back pain, you should talk to your doctor about the possibility of having vertebral osteomyelitis if you experience any of the following symptoms. Note that not all people with vertebral osteomyelitis have all of these symptoms:
- Weight loss
- Muscle spasms
- Bowel/bladder dysfunction
- Weakness in the legs or difficulty walking
- Sciatica, if the infection is in your low back
Chronic osteomyelitis can cause bone pain, recurring infections in the soft tissue over the bone, and pus drainage through the skin.
Diagnosing Vertebral Osteomyelitis
Your doctor may order a variety of tests to determine if you have vertebral osteomyelitis. Blood tests, such as the erythrocyte sedimentation rate, will show inflammation, but imaging scans will also be necessary to detect an infection. Computed tomography (CT) scans will highlight bone destruction, while magnetic resonance imaging (MRI) will be able to identify the source of pain as an infection—as opposed to a structural spinal problem (such as a herniated disc).
If the MRI shows signs of vertebral osteomyelitis, the next diagnostic step is to have a biopsy, which is a sample of the infection. There are two types of biopsies: The first is a needle biopsy, where a sample of the infection is obtained via a needle; the second is an open biopsy, where part or all of the infection is surgically removed. The biopsy results will help your doctor determine your course of treatment.
Treating Vertebral Osteomyelitis
The first line of treatment for vertebral osteomyelitis is a course of intravenous (IV) antibiotics administered in the hospital, followed by a few weeks of treatment at home. Once you complete your course of IV antibiotics, your doctor may prescribe oral antibiotics. You may also need a brace to immobilize you and reduce your pain.
As many as 18 percent of people with vertebral osteomyelitis have a second infection called an epidural abscess, which is an infection of pus within the spinal canal. Antibiotics will typically cure an epidural abscess as well.
If the infection does not respond to antibiotic treatment, or if you need infected bone or tissue removed, you will need surgery.
The goals of surgery may include cleaning and removing infected tissue and bone, and increasing blood flow to the infected area to promote faster healing. The surgeon will also restore spinal stability to the spinal bones impacted by the infection by using instrumentation such as rods, screws, interbody devices, or plates to stabilize the spine.
Another surgical option is spinal fusion. This procedure uses bone graft to allow new bone to grow around and into the surgical area, healing and solidifying the bone. Bone graft can be taken from the patient, from other individuals, or can be made from other natural or manmade materials.
Vertebral osteomyelitis can cause symptoms that limit your activity level and reduce your quality of life. But you can adequately treat this spinal infection—typically without surgery—with an early diagnosis.