Spinal Stenosis The winding road from pathophysiology and imaging to surgical results

Lumbar Spinal Stenosis (LSS) a common degenerative condition, mainly causes neurogenic claudication. The size of the lumbar canal reaches its adult dimension at an early age, influenced by ante-natal factors, and tends to decrease in recent generations, according to our studies. The pathophysiology of neurogenic claudication remains poorly understood. An initial hypothesis attributed the symptoms to traction of the rootlets during walking, but a pilot study using a robotic exoskeleton simulating passive walking in symptomatic subjects ruled out this hypothesis, making a vascular origin of the symptoms more likely.

The most reliable measure of the degree of stenosis considers the ratio between the rootlets and the cerebrospinal fluid surrounding them. Morphological classification into four grades (A, B, C and D) offers a clinical prognostic value superior to morphological signs such as the sedimentation sign or redundant rootlets.

Treatment of LSS resistant to conservative measures involves surgical release of nerve structures. Indirect decompression by interspinous distraction has fallen out of favour due to long-term failures, although its initial results were promising. Current trends support less invasive approaches, such as bilateral microscopic decompression and, more recently, endoscopic techniques, which are promising.

Several studies have demonstrated the superiority of surgery over conservative treatment in symptomatic patients, supporting this approach even in elderly patients.
Prof Constantin Schizas - Neuro-Orthopaedic Spine Unit Cecil Clinic Lausanne
Switzerland