Lumbar Spinal Stenosis: How Is It Classified?

Gregory D. Schroeder, MD; Mark F. Kurd, MD; Alexander R. Vaccaro, MD, PhD, MBA


J Am Acad Orthop Surg. 2016;24(12):843-852. 

In This Article

Abstract and Introduction


The prevalence of lumbar spinal stenosis is approximately 9.3%, with people most commonly affected in the sixth or seventh decade of life. Patients often have pain, cramping, and weakness in their legs that is worsened with standing and walking. Although the Spine Patient Outcomes Research Trial clearly demonstrated that surgery improves health-related quality of life, treatment for lumbar spinal stenosis varies widely from the type of decompression performed to the need for fusion. This variability can be attributed largely to the lack of an accepted classification system. A good classification system serves as a common language to define the severity of a condition, guide treatment, and facilitate clinical research.


Lumbar spinal stenosis (LSS) is a nebulous diagnosis indicating a narrowing of the lumbar spinal canal resulting in compression of the neural elements.[1] Although LSS is the most common reason for lumbar spine surgery in patients aged >65 years,[2] the condition is frequently associated with other pathology, such as degenerative spondylolisthesis and degenerative scoliosis; in addition, the radiographic findings do not always correlate with the clinical symptomatology.[3] Thus, high-quality epidemiologic data are limited. As part of the Wakayama Spine Study, Ishimoto et al[4] evaluated 1,009 subjects in Japan with a mean age of 66.3 years and reported that the prevalence of symptomatic spinal stenosis with or without additional pathology was 9.3%. Deyo et al[5] used the International Classification of Diseases, Ninth Revision codes and the Medicare Provider Analysis and Review database, which includes all Medicare hospital claims, to determine that 1.4% of Americans aged >65 years undergo surgery for lumbar stenosis yearly, a percentage that has remained fairly stable over the last decade. However, this percentage substantially underestimates the number of patients with radiographic lumbar stenosis and substantially overestimates the number with isolated symptomatic lumbar stenosis who require surgery.

Currently, the best available data on the epidemiology of isolated spinal stenosis in North American patients comes from the Spine Patient Outcomes Research Trial (SPORT). Weinstein et al[6] reported that the average age at presentation was 64.6 years, and the diagnosis was slightly more common in men (1.55 men to 1.0 women). Additionally, the average body mass index of patients was 29.5 kg/m2, and 84% of those seeking treatment were Caucasian.[6] Although this racial disparity has been reported in other large database studies,[7] it is unclear whether it represents an actual increase in pathology in Caucasians or more likely reflects differences in access to care and in cultural attitudes toward surgical intervention.