Lumbar spondylosis comprises degenerative disorder of the lumbo sacral region of the spine and is referred to as lumbago, sciatica or prolapse intravertebral disc (PID). There is intervertebial disc degeneration osteophyte formation and pain in low back, radiating down to lower extremities.
The spinal column is well adapted to various wears and tears of daily existence. While the anterior part consisting of lumbar bodies and disc constitutes the weight bearing area, the posterior part (Pedicles, facet joints and inter articular surface) give flexibility.
The spinal cord lies in the posterior part of the spinal column and ends opposite the lower border of Li and upper border of L2 vertebrae. Persons with intervertebral degeneration, osteoarthritis of the spine and mechanical injury are liable to develop lumbar disc lesions.
Lumbar spondylosis is more at the lower end of the spine since this part bears the brunt of the stress. Once a tear occurs in the annulus, the central tissue gets out and protrudes backwards. This presses upon the nerve roots and causes compression resulting in prolapsed disc.
This is the commonest cause of pain in low back and is often referred to as sciatica as the pain is in the distribution of sciatic nerve.
Another important cause is lumbar canal stenosis both congenital and acquired. This produces intermittent and chronic compression of the lower nerve roots leading to picture of cauda equina. This is further worsened by disc prolapse or spondylotic changes. The pathology in the whole process is like that in case of cervical spondylosis.
Clinical features of Lumbar spondylosis
Classically patient complains of pain in the lower back, buttocks, thighs and calves.
The pain comes suddenly, is sharp and more marked during active movements. ‘With rest the pain subsides.
Acute back pain starts suddenly following awkward bending, stooping or lifting a heavy weight. It is often aggravated by coughing or sneezing. Pain is in the distribution of the nerve pressed upon. There may be paresthesiae and numbness in the lower limbs and occasionally muscle weakness.
Physical examamination of Lumbar spondylosis shows tenderness of relevant lumbar spine and pressure at the point may produce sharp tingling pain. Straight leg raising test (SLR) is positive and there is weakness of dorsiflexion and lateral rotation of the foot.
The angle of the leg from the flat plane of the bed at which the pain is produced should be assessed. The lower the angle more severe is the nerve root compression.
In a normal person, SLR is negative upto 90 degrees of leg elevation while in a patient with disc prolapse it is generally around 30-40 degrees. Deep reflexes may be either absent or diminished.
Diagnosis of Lumbar spondylosis
In acute case clinical picture is specific X-ray lumbo sacral spine shows narrowing of disc space, osteophyte formation and loss of lumbar contour.
CT scan and MRI scan are sensitive tests to delineate the anatomy of the spine. Patients who have features of wasting of muscles and bladder symptoms, contrast myelography is indicated.
Electromyography may show nerve root involvement. This test may be useful only in small percentage of cases. But while making a diagnosis of lumbar disc prolapse, other conditions like tuberculosis of the spine, spinal tumours, ankylosing spondylitis etc must be excluded. Moreover every case is not always due to disc protrusion. Muscles and ligamentous strain along with bad posture and obesity also may be operative.
In acute attack of Lumbar spondylosis, patient must be put to bed rest along with non-steroidal anti- inflammatory agents. Staying in hard bed on a firm mattress for 3-4 days in usually sufficient.
Inermittent spinal traction and manipulation can also be tried. Extension exercises and use of suitably designed lumbar braces or corset are beneficial.
Radiant heat in the form of ultrasonic wave or short vave diathermy have important role. Once the acute pain settles down, patient must avoid strenuous exercise or lifting of heavy objects. Attempt be made to maintain correct posture while sitting or at work.
In case the above measure do not help and symptoms progress with wasting of limb muscles and bladder involvement, surgery is contemplated.
The operation of choice is micro disiectomy as it is less invasive and superior to conventional disiectomy. Recovery following surgery can take from 3-4 months. Even after this due precautions must be taken.
Indications for surgery in Lumbar spondylosis
1. Progressive disease
2. Distressing root pains
3. Neurological deficit
4. Bladder involvement