Diseases of the spine Intervertebral disc lesions

Intervertebral disc lesions Lumbar backache is one of the most common causes of chronic disability, backache is associated with some abnormality of the intervertebral discs at the lowest two levels of the spine (L4/5 and L5/S1).

Prolapsed intervertebral disc In acute disc herniation the gelatinous nucleus pulposus squeezes through the fibers of the annulus fibrosus and bulges posteriorly or posterolaterally beneath the posterior longitudinal ligament.

Local edema may add to the swelling, causing pressure on one of the nerve roots. With a complete rupture part of the nucleus may sequestrate and lie free in the spinal canal.

Symptoms depend on the structure involved and the degree of compression. Pressure on the ligament probably accounts for backache; pressure on the dural envelope of the nerve root causes severe pain referred to the lower limb (sciatica); compression of the nerve root itself causes pnumbness and parasthesia and muscle weakness.

Clinical features: Patient is usually a young adult, during lifting or other severe activities sudden severe backache day or two later the pain is felt down in the buttocks or the calf (sciatica) Both backache and sciatica get worse by coughing or sneezing or straining. neurological symptoms may show according to the severity of the prolaps and its direction and those may include sphenecteric disturbances.

Patient stands with lateral deviation or list of the back (sciatica scoliosis), there is limitation of all back movements. There is often tenderness in the midline of the low back, and paravertebral muscle spasm. Straight leg raising is limited and painful on the affected side; dorsiflexion of the foot may accentuate the pain. Sometimes raising the unaffected leg causes acute sciatic tension on the painful side (crossed sciatic tension’).

Neurological manifestations are:

X-ray: It does not show the disc itself, it exclude other bony lesions it can show associated muscle spasm as obliteration of lumber lordosis (straight spine) or scoliosis or both. Later on there may be narrowing of the disc space.

Mylography used to help but now it’s widely replaced by the more useful studies of MRI or sometimes CT-scan.

Treatment: Symptomatic drug treatment may include painkillers and NSAID with physiotherapy 10-14 days of bed rest and skin traction on a hard mattress can help autoreduction of the prolapsed disc, otherwise the prolapsed disc must be removed surgically (discectomy).

Indications for discectomy are: Cauda-eqina lesion (saddle parasthesia, paraparesis and uncontrolled bladder). Increasing complaint and pain despite treatment. Neurological deterioration despite treatment. Frequently recurrent attacks.

Complications: Lumber instability and later spondylosis. Spinal stenosis.