An Overview of Lumbar Foraminal Stenosis
(Collapse of the Lumbar Spine)
Lumbar foraminal stenosis (collapse of the lumbar spine) is very similar to lumbar spinal stenosis in the sense that it involves the narrowing of an area within the spinal canal. The individual nerves will exit through a small hole in the side of the spine in between the two vertebrae. This nerve root exiting occurs at every level in the spine. Do not confuse this condition with lumbar central stenosis where all the nerves in the canal are compressed. With lumbar foraminal stenosis, the compression is at the exit hole of the nerve (the foramen). Since the exiting hole is known as the foramen, narrowing of this hole is called foramenal stenosis (obviously- stenosis means narrowing). The stenosis is caused by the clogging of this nerve opening with bone spur, debris from degenerative facet disease and/or unilateral collapse of the disc (foramenal collapse).
The biomechanics are very easy to understand. The nerve hole is made up of a clam shell of the vertebra above and the vertebra below. This hole enlarges with bending forward and narrows with bending backwards and to the side of the hole (right sided hole will narrow with right lateral bending). If the hole is clogged up or the nerve root is swollen (which can happen to a pinched nerve), the nerve will be compressed with standing and walking and relaxed with sitting forward, crouching and leaning over a counter (or shopping cart).
Symptoms of Lumbar Foraminal Stenosis
The most common symptom associated with collapse of the lumbar spine is unilateral or one-sided buttocks or leg pain with standing and walking. This pain goes away with sitting forward, crouching or leaning over a counter (or even a shopping cart). When the pain occurs, it normally starts in the buttocks and with prolonged standing, will radiate down the front or rear of the leg. It can be a pins and needles pain or just numbness.
Treatment of Lumbar Foraminal Stenosis
Most of the time, this lumbar foraminal stenosis is not dangerous. That is, when the nerve is compressed and pain occurs, the individual can simply lean forward to “get off the nerve”. Permanent damage to the nerve is normally less that 5%. Treatment includes physical therapy and a “flat back” program, medications and spinal injections. Education to avoid certain activities and sports that cause extension is important.