Spine - 2026-08-17 - Journal Article
Prevalence of Lumbar MRI Changes Associated with Nerve Root Compression Among Middle-aged People - A Northern Finland Birth Cohort 1966 Study.
Ulenius S, Järvinen J, Niinimäki J, Arokoski J, Karppinen J, Oura P, Määttä J
Topics
Key Takeaway
In an unselected population of 1,440 middle-aged adults (age 45–47), focal disc protrusions were present in 38.2% and central stenosis in 99.1% of cases, with severity predominantly mild across all pathology categories.
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Summary
This cross-sectional study quantified the prevalence and severity of lumbar MRI findings associated with nerve root compression in an unselected population-based cohort aged 45–47 from the Northern Finland Birth Cohort 1966. Lumbar MRI was performed on 1,440 participants and evaluated for disc herniations, canal compromise, central/lateral recess/foraminal stenosis, spondylolisthesis, and synovial cysts. Focal protrusions were found in 38.2%, extrusions in 11.4%, mild central stenosis (Grade A) in 99.1%, mild lateral recess stenosis (Grade 1) in 53.8%, and all spondylolisthesis cases were Grade I, with severity predominantly mild across all categories.
Key Limitation
No clinical symptom data or neurological examination findings were linked to the imaging findings, making it impossible to determine what proportion of these MRI changes are clinically relevant.
Original Abstract
STUDY DESIGN
A cross-sectional study.
OBJECTIVE
To evaluate the prevalence of lumbar MRI changes associated with nerve root compression in a large, unselected middle-aged population.
SUMMARY OF BACKGROUND DATA
While degenerative spinal changes are frequently observed in imaging, their clinical relevance remains poorly understood. Furthermore, large-scale, population-based studies evaluating comprehensively the full spectrum of lumbar spine imaging variations associated with nerve root compression in MRI are lacking.
METHODS
At the age of 45-47 years, Northern Finland Birth Cohort 1966 members were invited to a follow-up. As part of the follow-up, lumbar MRI was performed on 1,534 participants in the Oulu region. Due to missing images and withdrawn consents, the final number of scanned individuals included in our study was 1,440. The following MRI changes were evaluated: disc herniations (both axial and sagittal planes), the degree of canal compromise, central and lateral recess stenoses, foraminal stenosis, spondylolisthesis and synovial cysts. Prevalences were reported descriptively.
RESULTS
The prevalence of focal protrusions across the whole lumbar spine (at least one finding at any lumbar level) was 38.2%, while broad-based protrusions accounted for 24.0%. Of the disc herniations, 11.4% were extrusions and 0.3% were sequestrations. Disc herniations were mostly central and located at disc level, and the degree of canal compromise was mild in 46.8% of the cases. The prevalence of mild changes was 99.1% in central stenosis (Grade A), 53.8% in lateral recess stenosis (Grade 1), 6.0% and 26.2% in foraminal stenosis (Grade 1, transversal and vertical perineural obliteration) and 100% in spondylolisthesis (Grade 1). Grade 2 was the highest grade of synovial cysts (prevalence of 0.3%) with no cysts of grades 3-5.
CONCLUSION
Lumbar MRI changes associated with nerve root compression were frequent, and their severity was mostly mild in general middle-aged population.