Defining Spondylosis Beyond Age-related Spinal Degeneration
Meeting Highlight from NASS 2014
During the symposium, “Section on Radiology: Controversies in Spine Imaging,” Joseph P. Gjolaj, MD presented, Spondylosis: What is Normal Age-related Degeneration? Dr. Gjolaj is an orthopaedic spine surgeon at the University of Miami Health System in Miami, FL.
“With spondylosis, it’s such a broad topic I start to think, well what does the Merriam-Webster dictionary say about this issue? And I find that it says spondylosis is any of the various degenerative diseases of the spine. So that’s quite vague. We can think a little bit further to assume that it’s related to age … it may or may not be associated with pain. Other than that, it’s not really a very well defined or classified in the spinal literature,” stated Dr. Gjolaj.
While the Kellgren-Lawrence spondylosis classification was applied to the cervical spine, it is applicable to the lumbar spine too.
- Grade 0: Absence of disc degeneration1
- Grade I: Minimal anterior osteophytosis1
- Grade II: Definite anterior osteophytosis, possible disc space narrowing, some sclerosis of the vertebral endplates1
- Grade III: Moderate disc space narrowing, definite sclerosis of the vertebral endplates, osteophytosis1
- Grade IV: Severe disc space narrowing, sclerosis of the vertebral endplates, large osteophytosis1
Fardon, et al published “Lumbar disc nomenclature: version 2.0” that specifically discusses lumbar disc pathology.2 “This is sort of next step beyond that in determining and standardizing classification systems,” stated Dr. Gjolaj.
Many studies show that spondylosis is prevalent in about 80% of people over age 60 years. In one study, 10% of people in the 20-29 year age group has spondylosis.In a large population study conducted in the United Kingdom, patients over age 50 years showed spondylosis was prevalent in 84% of men and 74% of women subjects.
MRI Findings Common
While MRI findings are common, a study by Scott Boden, MD in the Journal of Bone and Joint Surgery demonstrated that image findings do not automatically correlate with clinical symptoms.3 “Dr. Boden’s study found 80% of asymptomatic individuals above age 60 years had disc protrusions, and 21% had spinal stenosis—yet none of the study subjects had symptoms,” stated Dr. Gjolaj.
Besides age, what else?
- Body mass index (BMI)
- Spine trauma
- Spine/physical loading
- Whole body vibration
“We certainly see patients with neck and back pain, but I caution you that radiographic degeneration doesn’t reliably correlate with pain severity,” commented Dr. Gjolaj.
What about patients with a suspicious radiographic presentation? Or an x-ray that is inconsistent with the patient’s age? There are other clinical entities to be considered, including discitis, osteomyelitis, or malignancy. Dr. Gjolaj suggested, “advanced imaging: CT, MRI with and without gadolinium, and a biopsy.”
The ROAD (Research on Osteoarthritis-osteoporosis Against Disability) was a large-scale population study conducted in Japan to measure prevalence of knee osteoarthritis and lumbar stenosis. The 3,040 participants were divided into six groups based on their age. The incidence of lumbar stenosis by age is shown below.4
- ≤39: Men—14.3%, Women—9.7%
- 40-49: Men—45.5%, Women—28.6%
- 50-59: Men—72.9%, Women—41.7%
- 60-69: Men—74.6%, Women—55.4%
- 70-79: Men—85.3%, Women—75.1%
- ≥80: Men—90.1%, Women—78.2%
Obesity and occupational activities were associated with lumbar stenosis. The study also determined the radiographic severity of lumbar stenosis using the Kellgren-Lawrence classification. The authors examined the association between radiographic severity and low back pain.4
Recalling the Kellgren-Lawrence classification, the authors of the ROAD study applied it to the lumbar spine. For the purpose of the study, the authors focused on Grades II and III as the clinical standard for spondylosis.
- Grade II: Osteophyte formation alone (76%, mostly men)
- Grade III: Osteophyte formation and disc space narrowing (50%, mostly women)
- Primary risk factors: Age and BMI
Dr. Gjolaj’s commented, “They found that a Grade II spondylosis was not significantly associated with back pain compared to Grade 0 or I. Grade III or above was associated with pain, but surprisingly only in women." In the ROAD study, occupations were in the areas of agriculture, forestry, and fishery; those workers had a higher risk for Grade II spondylosis or greater. Clerical workers (eg, sitting in a chair) had an inverse relationship to Grade II or higher lumbar spondylosis.
“I don’t think there’s really one perfect definition of what’s considered normal age-related degeneration, but I would argue that many of us know it when we see it. The standard terminology is really paving the way for us to understand what’s normal and how to describe it to colleagues as what’s normal or abnormal,” stated Dr. Gjolaj.
Studies, including the ROAD study have shown some radiographic correlation. “We know spondylosis increases with age, is not necessarily associated with pain severity, and may or may not have a relationship to other occupations. These are helping us pave the way to make the spondylosis question less controversial," concluded Dr. Gjolaj.