A Family Doctor's Tale - PROLAPSED INTERVERTEBRAL DISC

DOC I HAVE A PROLAPSED INTERVERTEBRAL DISC

A prolapsed intervertebral disc usually occurs in elderly men and women who over exerts their back. Due to their age, degeneration of the ligaments holding the intervertebral disc has weakened resulting in  the disc being pushed out of its weakened capsule. The protruding disc will then press against a nerve causing pain. In a rare case, a young woman of 30 years had a prolapsed intervertebral disc due partly to her obesity and her frequent slouch over the computer. In most cases conservative treatment like traction and physiotherapy normally help the disc to slip back into its capsule with relief. In severe cases surgery is needed.

Prolapsed Intervertebral Disc is the prolapse of the intervertebral disc(which is the disc between 2 vertebrae) as a result of protrusion of the nucleus pulposus out of its weakened ligamentous ring(annulus fibrosus).


It may protrude in a posterior or posterolateral direction causing pressure to the nerve roots especially at S1, L5 and L4 vertebrae.


Causes are:
1.Degeneration of the posterior longitudal ligaments and annulus fibrosus occurs with age resulting in the disc being pushed out between the weakened ligaments.


2.Trauma -direct injury to disc, heavy lifting, sneezing can cause the disc to pop out of the weakened ligaments and prolapse partially or completely.


3.Spinal tumor rarely pushes the disc out of its intervertebral space


Symptoms:
1.Low Backache with pain in the lumbar region


2.Sciatica or pain shooting down 1 leg


3.Pain usually follows
severe bending
lifting heavy objects
injury
sneezing or coughing


4.Pain may so bad that the person cannot stand erect.


5.Pain is worse when sitting


6.Weakness, numbness, difficulty in moving the leg


Signs:
1.Muscle spasm especially spinal extensor muscles


2.Movement of the back and affected led painful and restricted


3.Patient tend to stand stiffly or with slight sciatic scoliosis on the affected side


4.Straight leg raising test is usually restricted on the affected side.


5.Neurologic signs such as paresthesia commonly present on the affected side.


6.Sensory and motor deficit may be present in the affected side


7.Loss of reflex and weakness may help to localize the site of prolapse:
L4 root
Pain in the medial buttock, lateral thigh, medial tibia and big toe
weakness of big toe and foot dorsiflexion
patella jerk is diminished


L5 root:
Pain in hip, groin,posterolateral thigh, lateral calf and dorsal surface of foot
weakness of the big toe and foot dorsiflexion
no change in patella or ankle reflexes


S1 root:
pain in posterior part of thigh, lower calf border and sole of foot
weakness of knee flexors and plantar flexors
ankle jerk is diminished


Diagnosis is made by:
1.Full medical history especially of injuries, type of work, onset of pain,radiation to legs,


2. Full medical examination  especially of movement of the back ,any deformity of the spine,  straight leg raising test


3. X-ray of the Spine: to exclude osteoarthritis, injury, narrowing of disc space,  bone tumor,


4.MRI of spine for slipped disc


5.Bone scan for osteoporosis


A definite diagnosis can then be made and the cause of the pain treated.


Conservative treatment:

Initial phase:
1.Bed rest with a hard board below the mattress- straighten the back

2.Physiotherapy such as traction, shortwave diathermy


Mobilization phase:
1.Wearing a corset to straighten the back and help the traction of the spinal bones

2.gradual mobilization and exercises to strengthen the spinal extensor muscles


Maintenance phase:
1.Exercises to strengthen the back muscles.

2.Wear a corset

3.Avoidance of postural strain on the back


Drug Therapy:

1.Pain killers such as NSAID(non-steroidal anti-inflammatory drugs) for pain

2.Muscle relaxant to relax muscles

3.Extradural injection of local anesthetic and long acting steroid may help to relieve the pain


Surgery:
Surgery is required if there are:
1.persistent pain and neurological symptoms remain after conservative treatment

2.progressive neurological symptoms

3.Disc has protuded more than 75% out of its intervertebral space as seen on MRI


Surgery consists of:
1.laminectomy - removal of the disc and prolapsed material.

2.microdiscectomy- insertion of a titanium disc to replace the removed prolapsed disc


Finally treatment of the underlying cause(eg.space occupying spinal tumors) is important.


Prognosis depends on the underlying cause.


Preventative measures are important in preventing recurrences of the prolapse of the intervertebral disc.


Avoidance of postural strain on the back


Wear a corset


Exercises to strengthen the back muscles.