spine
Lumbar Spinal Stenosis
intermediate
6 min
28 marks
6 questions
Clinical Scenario
A 70-year-old retired farmer presents with a 3-year history of bilateral leg heaviness and pain when walking. He can manage approximately 100 meters before needing to stop and lean forward or sit down. He finds walking uphill harder than downhill, and can cycle without problems. His symptoms are relieved within minutes of sitting. He has tried physiotherapy and two epidural injections with temporary relief.
Axial and sagittal T2-weighted MRI demonstrating severe central canal stenosis at L4-5 with trefoil-shaped canal. There is bilateral ligamentum flavum hypertrophy, facet joint hypertrophy, and disc bulge causing circumferential compression of the cauda equina. Multiple levels show degenerative changes. This represents degenerative lumbar spinal stenosis causing neurogenic claudication.
Source: Sacral Insufficiency Fractures Mimicking Lumbar Spine Pathology • PMC4917777 • CC-BY
Questions
Question 1 (4 marks)
Describe the MRI findings and classify this stenosis.
Question 2 (5 marks)
What are the clinical features and how do you differentiate from vascular claudication?
Question 3 (6 marks)
What is the evidence for treatment and when do you recommend surgery?
Question 4 (5 marks)
Describe your surgical technique for decompression.
Question 5 (4 marks)
When is fusion indicated and what are the fusion options?
Question 6 (4 marks)
What are the expected outcomes and complications?
Exam Day Cheat Sheet
Must Mention
- •Neurogenic claudication: positional, bicycle test positive
- •Vascular: cramping, relieved by standing still
- •SPORT trial: surgery superior for stenosis
- •Decompression alone if no spondylolisthesis
- •Fusion if spondylolisthesis or instability
- •Preserve facets (<50%) to prevent instability
Common Pitfalls
- •Missing vascular claudication
- •Not knowing SPORT
- •Unnecessary fusion
- •Excessive facet removal
- •Incomplete lateral decompression
- •Missing instability