Spinal stenosis (SS) is a narrowing of the spinal canal or the openings for the spinal nerves. It is a common change that occurs with aging. Lumbar spinal stenosis is a frequent cause of low back pain and neurologic changes in the leg(s).
In this study, the size of the spinal canal was measured and compared with patient symptoms. The goal was to see if spinal canal diameter was linked with severity of symptoms.
Pain, perceived function, and walking distance were used as measures of results. MRIs of the lumbar spine showed the spinal canal size and condition of the spinal structures (ligaments, disc, joints).
Patients with the smallest openings were more likely to have bulging discs, thickened ligaments, and joint changes. A small number of patients with spinal stenosis did not have any of these types of changes.
Although patients with the smallest canal diameter had more pain below the knee, this finding was not statistically significant. Almost half of the patients with larger spinal canals also had pain below the knee. It’s likely that some other factor besides canal diameter is the cause.
Pain intensity, walking ability, and function were not different between patients with smaller versus larger spinal canals. Patients with the smallest canal diameters did report more pain-related disability. This has more to do with perception of pain than canal size.
The authors of this study point out that these results support other research that shows the anticipation of pain and not the actual pain felt is most predictive of function. Fear of pain and changing activity levels to avoid pain may be the real issue here, not the size of the spinal canal. Further study is needed to examine this more.