spinal stenosis

A condition due to narrowing of the spinal canal causing nerve pinching which leads to persistent pain in the buttocks, limping, lack of feeling in the lower extremities, and decreased physical activity.

Lumbar spinal stenosis is a condition due to narrowing of the spinal canal causing nerve pinching which leads to persistent pain in the buttocks, limping, lack of feeling in the lower extremities, and decreased physical activity. More specifically, there are several different forms of lumbar spinal stenosis.

The most common is degenerative stenosis, occurring in virtually the entire adult population as a result of the natural process of aging. It is a degenerative narrowing of the spinal canal, nerve root canals and/or intervertebral foramina caused by bone and/or ligament hypertrophy in local, segmental or generalized regions. The narrowing results in compression of spinal nerves and nerve roots, causing a constellation of symptoms, including lower back pain, neurogenic claudication and lower extremity pain.

Congenital lumbar stenosis is relatively rare and usually presents at an early age, often between 30 and 40. Acquired LSS is more common and generally develops when patients are in their 60s or older. It is a puzzling condition that can neither be predicted nor prevented. It does not distinguish by sex, race, or ethnicity. Nor is it associated with any particular occupation or any particular body type.

Symptoms

• Dull to severe aching pain in the lower back or buttocks when walking or other activities.
• Pain radiates into one or both thighs and legs (60% bilateral pain).
• Numbness,weakness or paraesthesia involving the lower extremities.
• Symptoms relieved by bending forward, sitting or lying down.
• Pain relievers tend to be ineffective
• Decreased endurance in physical activities

Development/Causes

Complex changes in the vertebral structures and ligaments of the spine contribute to the development of acquired lumbar spinal stenosis. As the body dehydrates with age, bones become less dense and the discs of the spine lose mass. The discs compress, causing tilting, slippage and rotation of vertebral bodies. This results in compression of the spinal sac and nerve roots. In some cases, bone growth is stimulated and osteophytes form in the lateral recess and intervertebral foramina as the spine tries to stabilize itself. This can cause compression of nerve roots as they exit through the foramina to the lower back and legs, leading to chronic back pain and intermittent weakness and numbness in the legs.

At the same time, hypertrophy( enlargement) of the spinal ligaments (ligamentum flavum) can reduce the space available for the spinal sac, causing further compression of the nerve roots. These ligaments stiffen with age and begin to buckle into the spinal canal, creating additional points of compression and pain. Arthritis often compounds the problem by increasing the stiffness and inflexibility of the ligaments and joints.

In addition to the body's dehydration with age, the physiological changes responsible for LSS are thought to have their genesis in four areas.

Listed from most common to rare:

1. Degenerative causes such as spondylosis, spondylolisthesis, hypertrophy of the ligamentum flavum, and synovial cysts are the main etiology of LSS by far.
2. Traumatic causes such as vertebral fractures and subluxation, complications following laminectomy such as epidural fibrosis and herniated discs.
3. Skeletal causes such as metastatic cancer of the spine, rheumatoid arthritis, Paget's disease, ankylosing spondylitis and diffuse idiopathic skeletal hyperstosis (DISH).
4. Metabolic and endocrine causes such as acromegaly, pseudogout, renal osteodystrophy, hypoparathyroidism or, in rare cases, Cushing's disease.

TREATMENT:

Conservative measures can be tried first. These include pain killers and anti-inflammatory medication and physiotherapy.

If this does not work we try some injections – to inject some local anesthetic and steroids around the inflamed nerve- the 2 procedures we use are called an epidural injection or a nerve root block.

If these measure do not wok then we may need to consider surgery- taking the pressure off the nerves and  stabilising the spine if needed .  The operation is called a lumbar decompression and stabilisation.