What causes cervical stenosis?

What Causes Cervical Stenosis

Cervical stenosis results from either congenital developmental narrowing of the spinal canal or acquired degenerative changes affecting the facet joints, intervertebral discs, and ligamentum flavum, with the degenerative form being far more common in clinical practice.

Congenital (Developmental) Causes

Congenital cervical stenosis (CCS) occurs when individuals are born with an abnormally narrow spinal canal due to developmental anomalies. 1

• Anatomical characteristics include multilevel canal narrowing at three or more vertebral levels, with specific cut-off diameters: C3 <12.9 mm, C4 <11.8 mm, C5 <11.9 mm, C6 <12.3 mm, and C7 <13.3 mm 2
• Approximately 13% of the general population has multilevel developmental cervical stenosis 2
• Racial predisposition exists, with Black patients showing 39.3% prevalence, Asian patients 33.6%, Hispanic patients 22%, and White patients only 7.5% 3
• The condition is caused by abnormal spinal canal anatomy during development, resulting in reduced sagittal diameter from birth 1

Genetic Syndromes

Achondroplasia represents a specific genetic cause of cervical stenosis, resulting from mutations in the fibroblast growth factor receptor 3 (FGFR3) gene 4

• This condition produces characteristic spinal anomalies including mushroom-shaped vertebral bodies, shortened and thickened pedicles, and short interpedicular distances 4
• These anatomical changes lead to foramen magnum narrowing and cervicomedullary compression 4

Acquired (Degenerative) Causes

The most common cause of cervical stenosis in adults is degenerative changes affecting multiple spinal structures. 5

Primary Degenerative Processes

• Facet joint arthropathy and hypertrophy progressively narrow the spinal canal and lateral recesses 5
• Intervertebral disc degeneration with bulging or herniation reduces the anteroposterior diameter of the canal 5
• Ligamentum flavum buckling and hypertrophy contributes to posterior canal narrowing, particularly with neck extension 5
• Ossification of the posterior longitudinal ligament (OPLL) causes progressive canal narrowing, typically presenting in the fifth or sixth decade with a 2:1 male-to-female ratio 6

Biomechanical Factors

• Cervical spine extension produces statistically significant stenosis compared to flexed or neutral positions 7
• Long periods of severe stenosis lead to demyelination of white matter and potentially irreversible neurological deficits 8, 6
• Disproportionate spinal biomechanics in congenital cases predispose to accelerated degenerative changes 4

Clinical Significance of Etiology

Understanding the underlying cause is critical because congenital stenosis predisposes individuals to earlier symptomatic degenerative disease. 1

• Individuals with developmental cervical stenosis have 6.12 times higher odds of developing degenerative cervical myelopathy requiring surgery 2
• Males with multilevel developmental stenosis face particularly high risk and require close monitoring 2
• The combination of congenital narrowing plus acquired degenerative changes creates a "double-hit" phenomenon that accelerates symptom onset 1

Common Pitfall

Do not assume all cervical stenosis is degenerative—failure to recognize congenital stenosis in young patients or athletes can lead to catastrophic spinal cord injury with minor trauma, as these individuals have reduced reserve capacity in the spinal canal 1, 3