Causes of Back Pain - Infections

If one or more the structures of the back were to become infected, it could cause the symptom of back pain. Infections in the back may occur for one of two reasons:
  1. Infections of the back which cause back pain may be a complication of back surgery.
  2. The infection may have started in another area of the body and spread to structures in the back.
Back Surgery, Infections, and Back Pain: One of the most recent comprehensive reviews of back surgery procedures yielded results indicating that the risk of infections after spine surgery was 2%. This research was presented at the 24th Annual Meeting of the North American Spine Society (NASS). The data about infection rate was collected and presented by the Scoliosis Research Society (SRS). This data was collected from over 100,000 back surgery cases, who received their spine surgery between the years of 2004 to 2007. A positive finding for infections was determined if the patient developed superficial or deep wound infections following back surgery. The spine surgery cases studied the following types of procedures, and here are the results (the percentages below represent the frequency of cases in which each type of spinal condition were treated):
  • 44% for spine surgery to treat degenerative conditions
  • 24% for scoliosis
  • 11% for spondylolisthesis
  • 3% for kyphosis
  • 3% for fractures
Among all of these procedures, between 0.8-1.2% of patients was treated for either superficial or deep wound infections. There was some variation among complication rates based on which type of back condition was being treated. For example, infection rates were as high as 4.2% for procedures involving the treatment of kyphosis and as low as 1.4% for procedures involving the treatment of degenerative conditions.

There was also some variation related to the specific type of spine surgery being performed. The surgeries that had comparatively higher infection rates included repeat surgeries to treat the same area that was operated on in a previous surgery, as well as surgeries that involved implantable devices. Procedures that had comparatively lower complication rates included minimally invasive procedures such as transforaminal lumbar interbody fusion (TLIF) and microdiscectomy.

Surgeries that involved spinal fusions had among the higher rates of complications, although the rates differed according to the specific types of spinal fusion procedures that were performed. For example, the infection rate for anterior-only fusions was only (0.6%). The infection rate for posterior fusions and anterior/posterior fusions was 3%. This complication rate was actually 5 times higher compared to the anterior only fusion.

This data was very useful for spine surgeons and experts in the field to gauge how safe each type of procedure was. This data allowed surgeons and the doctors who prescribed these types of procedures to fully understand the potential benefits and risks for patients, based on the specific medical problem the patient has, and the specific treatment being considered to manage the condition or cure it. Overall, these results indicate that risk of infections is fairly low at 2%. The results also indicate that the more invasive the surgery is, the greater the chance that the patient has for sustaining infections. The results also indicate that infections are an ever present problem that continued to occur, despite the best efforts of the hospitals to eliminate them completely and the best efforts of the best doctors.

Let's take a look at the condition of osteomyelitis, an infection of the vertebral body. The vertebral body is the weight bearing, hockey shaped section of the vertebra.

Osteomyelitis: Vertebral osteomyelitis is an infection of the vertebral body, which occurs due the spread of the infection to this part of the bone, through the bloodstream. This infection usually travels to the vertebral body from another area of the body. The most common route of transmission is from the veins of the lower spine (Batson's plexus), which drains from the pelvis, directly towards the vertebrae of the lumbar spine. Typically this is a bacterial infection. Vertebral osteomyelitis is one of the most common types of infections following a cystoscopy (urologic procedure).

This infection is rare in men and women with history of significant medical problems or surgeries. The populations of patients that are most likely to contract this type of infection include the elderly, intravenous drug users, and those with compromised immune systems.
The majority of patients with compromised immune systems include those with one or more of the following conditions:
  • Cancer patients and those on cancer fighting drugs
  • Those with nutritional deficiencies in their diet (malnutrition)
  • Post-operative organ transplant patients
  • AIDS/HIV AIDS stands for Acquired Immune Deficiency Syndrome
  • Insulin Dependent Diabetes Mellitus
  • Patients such as those with inflammatory arthritis conditions (e.g. rheumatoid arthritis) who require regular and repeated use of steroids
Specifically, the cause of this infection is most commonly due to the bacteria Staphylococcus Aureus. This is the most common type of bacterium which infects the vertebral bodies in the lower spine. Other types of bacterial infections which may infect the vertebral bodies include the Pseudomonas infection and Mycobacterium Tuberculosis.