A 65-year-old patient undergoes lumbar spinal stenosis surgery. The ligamentum flavum is hypertrophied and contributes to the stenosis. What is the histological composition of the ligamentum flavum that makes it prone to hypertrophy with age?

• A Primarily collagen type I with age-related calcification
• B Fibrocartilage with proteoglycan-rich matrix that becomes calcified
• C Dense irregular connective tissue with high collagen type III content
• D Approximately 80% elastic fibres and 20% collagen; degeneration leads to collagen replacement and hypertrophy ✓

Explanation

The ligamentum flavum is unique among spinal ligaments — it contains approximately 80% elastic fibres and 20% collagen, giving it its characteristic yellow colour (flavum = yellow in Latin) and elastic recoil that helps maintain spinal posture. With age, there is degenerative loss of elastic fibres and replacement with collagen, accompanied by fibrosis and proliferation — leading to hypertrophy and buckling into the spinal canal during extension, contributing to neurogenic claudication. Other spinal ligaments (anterior/posterior longitudinal) are predominantly collagenous.

Reference: BD Chaurasia's Human Anatomy, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.