Results of an Ongoing Lumbar Stenosis Study
The causes of low back pain and best ways to treat this problem continue to elude scientists, orthopedic surgeons, and other concerned health care professionals who treat these patients. In an effort to study every aspect of back pain, researchers have established the Spine Patient Outcomes Research Trial or SPORT as it is referred to most often.
Data is gathered from multiple spine centers where the focus is on spinal problems and especially back pain. By collecting the same information on every patient and putting it in a single database, researchers from around the United States can analyze the data looking for answers to specific questions. The authors of this study took a closer look at lumbar spinal stenosis (narrowing of the spinal canal) in an effort to see if stenosis at more than one level affects outcomes of treatment.
To break this down even further, it's helpful to know that spinal stenosis can occur in people who have good spinal alignment. There is normal vertebral alignment but other factors are impinging on the opening for the spinal cord. There could be osteophytes (bone spurs), thickening of the spinal ligaments, disc degeneration, joint hypertrophy (arthritic changes), or any combination of these age-related changes.
It's also possible that spinal stenosis can develop as a result of a condition called degenerative spondylolisthesis. This is another age-related condition affecting adults (most often women) over the age of 50. A fracture in the supporting column of the vertebra allows the body of the vertebra to slip forward over the vertebra below it. The forward shift narrows the spinal canal and puts a pulling or traction force on the spinal cord or spinal nerve roots (depending on the level affected).
Treatment for spinal stenosis is becoming more effective as we gain a better understanding of the underlying pathology. Studies show that age-related spinal stenosis responds well to conservative care, whereas patients with stenosis from degenerative spondylolisthesis do better with surgery to stabilize the spine.
Now with this study, we add an additional layer of understanding by looking at the results of treatment linked with number of spinal levels affected (one level, two levels, three or more levels). It boils down to one question: How do patients with spinal stenosis fare with and without degenerative spondylolisthesis at one versus multiple lumbar levels? Bear in mind we will be looking at the answer to this question for two types of treatment: surgical versus nonoperative (conservative care).
One of the nice things about using data from the SPORT study is that researchers can pull together a group of patients who are very similar in order to compare them equally. So in this study, they made sure everyone in the spinal stenosis group had been accurately diagnosed with X-rays and reported painful symptoms for at least three months. Everyone in the degenerative spondylolisthesis group had spinal stenosis associated with at least one level of spondylolisthesis. They were also symptomatic for at least three months.
Everyone in the SPORT studies completes a wide range of test measures. They fill out surveys and answer questions about symptoms, function, disability, general health, and overall satisfaction with their health status. By comparing these measures before and after treatment, it is possible to get an idea of how patients respond to surgery versus conservative care for both conditions (spinal stenosis with and without spondylolisthesis).
After examining the data collected, here are a few discoveries they made about patients in both groups:
The people with three or more levels of stenosis were much older and more likely to be men
The more levels affected, the more severe the condition and the symptoms
The most common level involved was L45
Before treatment, pain and disability was rated equally between the two groups
The authors thought that patients with single level spinal stenosis would do better than patients with multilevel stenosis when treated conservatively. Conservative (nonoperative) care includes bed rest, antiinflammatory medications, pain relievers, physical therapy, and steroids when necessary. But it actually turned out that the number of levels affected wasn't as important as the presence of degenerative spondylolisthesis.
Even if the patient had multiple levels of stenosis, if the vertebrae were in good alignment, they did well with nonoperative care. When surgery was the treatment of choice, results were not better for single level versus multiple level stenosis unless there was degenerative spondylolisthesis present. In other words, the presence of spinal stenosis associated with degenerative spondylolisthesis at several levels increased the risk of a poorer outcome.
Surgeons can assure patients with multilevel spinal stenosis without degenerative spondylolisthesis that conservative treatment works well for many people. Surgery can always be considered later if needed. Delaying surgery for a long as possible does not affect results later. In fact, even with multilevel spinal stenosis, patients can get better with less intense symptoms and improved daily function. Those who have degenerative spondylolisthesis should try conservative care first but may find surgery is necessary sooner than patients without spondylolisthesis.
Daniel K. Park, MD, et al. Does Multilevel Lumbar Stenosis Lead to Poorer Outcomes? In Spine. February 15, 2010. Vol. 35. No. 4. Pp. 439-446.