Spinal surgery is most often done for pain radiating down the lower limb more than for back pain. The cause for the pain down the lower limbs is caused by irritation of the nerves in the lumbar spine. As the spinal cord terminates before the lumbar spine, it is only nerve roots that terminate in the lower limbs that pass through the lumbar spinal canal.
Irritation of these nerves therefore cause lower limb pain that we refer to as Radiculopathy- Pain that radiates down the limb associated often with numbness and pins and needles.
When all the nerves are crowded by a narrow canal, it can cause Claudication pain.
Claudication pain is described as PAIN IN THE LOWER LIMBS – NOT IN THE BACK - brought on by walking or standing for long periods of time. The only way of relieving this pain is by sitting down or leaning forward. Once this is done, they can resume their walking for the same distance again before the pain resumes. They also note that the distance you can walk before the pain becomes intolerable becomes shorter. Another classical history is that they can walk long distances so long as they have a shopping trolley to lean on. Many also say that they have no problem cycling for any distance so long as they are slouched over their push bikes.
If the nerve is compressed by a Disc prolapse – A microdiscectomy is done
If the nerve is compressed by narrowing in the lateral aspects of the spinal canal and foraminotomy is done.
If all the nerve are clumped together by a narrow canal – a laminectomy is done.
If the nerve is compressed by a slip of the vertebrae or narrowing of the space between the vertebrae – a Lumbar fusion is done