Examqo › Examqo library › Orthopedic surgery › Spine · IMLE
Lumbar spinal stenosis
Degenerative narrowing of the lumbar spinal canal causes neurogenic claudication: pain, numbness or weakness in the legs on walking and standing, relieved by sitting and bending forward; treatment is conservative at first, and decompression (laminectomy) suits symptoms that are very limiting.
Why it matters in the exam
The typical stem describes a person over 60 who can walk only a short distance before the legs feel weak or numb and who must sit for the symptoms to pass. The patient feels better leaning forward on a shopping trolley or cycling, and walking uphill is easier than downhill, because bending forward widens the canal and straightening narrows it. The key differential is vascular claudication from peripheral arterial disease: there the pain settles on standing still without needing to sit, foot pulses are weak, and the pain also appears when cycling. The narrowing is caused by disc bulging, thickening of the ligamentum flavum and enlarged facet joints, and sometimes by degenerative spondylolisthesis at L4–L5. MRI confirms the diagnosis and shows the narrowed levels; in a patient who cannot have MRI, CT with contrast in the canal (myelography) can be used. The natural history is stable in most patients, so first-line treatment is physiotherapy with flexion exercises, analgesia and weight loss, and sometimes an epidural injection. Decompression suits patients whose symptoms greatly limit their quality of life despite conservative care, and relieves mainly leg pain and less back pain. When there is degenerative spondylolisthesis with instability, fusion is sometimes added. In clinical questions, also watch for warning signs that do not fit simple stenosis, such as weight loss, night pain or fever, which call for investigation of tumour or infection.
Key points
- Neurogenic claudication: leg pain and numbness on walking and standing.
- Relief by sitting and bending forward — the shopping trolley sign.
- Distinguish from vascular claudication by pulses and response to standing.
- MRI confirms; conservative care first.
- Decompression for limiting symptoms; fusion when there is instability.
Summary table
| Feature | Neurogenic claudication (stenosis) | Vascular claudication |
|---|---|---|
| Relief | Sitting or bending forward; standing still is not enough | Standing still relieves within minutes |
| Cycling and uphill | Cycling and walking uphill are better tolerated | Cycling and walking uphill worsen pain |
| Foot pulses | Normal | Weak or absent |
| Character of symptoms | Numbness, weakness and pain from the back into the legs | Cramping calf pain, cold skin |
| Confirming test | MRI of the lumbar spine | Ankle-brachial index and Doppler |
In the full version for subscribers
- A simple algorithm
- Memory aid
- Exam traps
- 5 review cards
- Enough for IMLE
The full version is open to subscribers of: Orthopedic surgery, Medical licensing exam (IMLE), Geriatrics, Neurosurgery, Family medicine.
Subscriber? Read the full topic Plans and prices 25 free questions
Sources
- NASS Evidence-Based Clinical Guideline, 2011 — Diagnosis and Treatment of Degenerative Lumbar Spinal Stenosis
- Campbell's Operative Orthopaedics, 14th ed. (2021) — Degenerative Disorders of the Lumbar Spine
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.