I am almost always taking care of at least one person with a spinal infection, at any one point in time. Thankfully, in the grand scheme of things, this is actually an uncommon infection.
It is felt, however, that spinal infections may be increasing a bit, particularly due to the fact that people are undergoing more medical interventions. These interventions potentially expose patients to infections.
Take back surgery for example. Back pain is a common complaint experienced by probably all of us at some point in our lives. Some people, however, experience chronic backpain which they find unbearable. Causes include severe arthritis, and herniated (or ‘slipped’) discs, among others.
Back surgery is more available now, and so more people are opting for various forms of back surgery to hopefully cure their pain. Aside from surgery, there are other interventions such as injection of pain blocking medications into the spine, and implantation of devices to stimulate the spinal nerves and block the pain.
As with any surgical or otherwise invasive intervention, infection is always a potential complication of the back procedures mentioned above. It can happen either during a procedure, if bacteria get introduced at the time it’s being done. Or, infection can happen after surgery, if the surgical wound somehow gets contaminated from the outside.
A common scenario I see where spinal infections are concerned, is in a patient who never had back surgery. They may either develop sudden onset severe back pain, often reporting that they woke up with this severe, unbearable pain. Alternatively it may be a back pain that’s steadily worsening over a period of weeks to months. The deceptive thing, is that fever is often absent.
How do these spine infections arise, in people who have never had surgery?
The first thing patients ask me about their spinal infection, is “how did this happen?” First of all, let’s look at where in the spine the infection can be. Spinal infections may come in different forms including an abscess along the spine, infection of the disc-like structure between two vertebral bones (discitis), infection of one of the vertebral bones (osteomyelitis), and infection of one of the little joints formed where the bones sticking out of the sides of the vertebral bodies meet (septic arthritis).
The scenario in someone without recent back surgery, is that they had an infection somewhere in their body, which ended up spreading to their blood stream. Usually this is some type of bacteria (though other germs such as fungi can be the culprit in rare circumstances). Bacteria circulating in the blood can reach anywhere in the body. However, one can imagine, that parts of the body with great supplies of blood will be more exposed to the bacteria. The lower spine happens to be one such area in the body where there is a rich supply of blood vessels.
Another feature of the lower spine is that it is a common area for arthritis to develop, having to bear quite a bit of the body’s weight. The presence of arthritis means that the spine is not perfectly normal. That is, there is some loss of integrity. Anywhere there is a defect, or loss of integrity, is an area which is more susceptible to infection. It’s a ‘weaker’ area. It is easier therefore, for bacteria to lodge or ‘stick’ to these more defective, less smooth, areas of the body. Here, they multiply and cause infection over time.
Diagnosing spinal infections
A CT or MRI scan is usually required to confirm the diagnosis of a spinal infection. Cultures of the blood are sometimes positive for the causative bacteria. Sometimes a biopsy is needed, where a sample of tissue is taken from the affected area of the spine with a needle. This tissue is cultured in the lab to attempt to identify the culprit germ.
There are times when we are unable to identify the culprit germ. In these cases we have no choice but to give a combination of antibiotics to cover the most likely causes in the particular individual.
Are these infections of the spine treatable?
Most certainly! Antibiotics given for a prolonged period is the cornerstone of treatment. Usually, antibiotics are given for 6 weeks. If the infection is extensive, treatment for 8 weeks or longer is sometimes required. Tissues of bones and joints are more dense, therefore antibiotics must be given for a prolonged period to ensure complete penetration of these tissues with antibiotics so that all the bacteria get killed.
In patients whose spinal infection was complicated by the formation of an abscess, drainage of the pus is often necessary for quicker resolution of the infection. Sometimes, simply inserting a tube into the abscess cavity drains all the pus. However, in other cases, surgery is required to cut open the area and wash out the pus.
Does one get back to normal after completing treatment for spinal infections?
I like to warn patients that they may have chronic bank pain indefinitely, due to the scaring that occurs after the infected area has healed. And after all, there was underlying arthritis in many patients, which can worsen after an infection. Older persons are more prone to having this persisting chronic back pain as they have more arthritis, and generally tend to be less mobile. But there are many patients who become pain free, after the infection is treated. Physical therapy increases the chance of a painless recovery.
The devastating complication of these spinal infections is paralysis. Sometimes the infection goes on for too long before a diagnosis is made and an abscess forms which gets bigger and bigger, until it presses on the nearby spinal cord, damaging it and causing paralysis. Aside from an abscess, the infected bone can get so damaged that it crumbles and presses onto the spinal cord. Fortunately, paralysis is a rare complication.
Spinal infections are generally rare, when the entire population is considered. If someone suddenly develops severe back pain which interferes with getting around, and it progressively worsens, medical attention should be sought.
In deciding whether or not to accept an invasive medical procedure, one should seriously consider the risk for infection, and decide whether their pain is severe enough, such that the benefits of invasive intervention outweigh the risks. Though everyone signs a consent form acknowledging the risks of infection with invasive procedures, too many patients realize only after an infection occurs, how real this risk was.