This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Upper Extremity, Subject name: Anatomy
A 45-year-old man is admitted to the hospital because of severe pain in the back and lower limb. Radiographic examination reveals spinal stenosis syndrome. Which of the following conditions is most likely to be confirmed by MRI examination? 
Select and explain. 
A. Hypertrophy of supraspinous ligament, B. Hypertrophy of interspinous ligament, C. Hypertrophy of ligamentum flavum, D. Hypertrophy of anterior longitudinal ligament
C: Hypertrophy of ligamentum flavum
Answer: C: Hypertrophy of ligamentum flavum 
Explanation: The ligamentum flavum connects the lamina of two adjacent vertebrae and forms the posterior wall of the vertebral canal. It is the only answer choice that is in direct contact with the vertebral foramen. Therefore, hypertrophy of only the ligamentum flavum would present as spinal stenosis. The supraspinous and interspinous ligaments connect spinous processes. The anterior longitudinal ligament connects the anterior portion of the vertebral bodies and intervertebral disks. Finally, the nuchal ligament is a thickened extension of the supraspinous ligament above the level of C7.