Prolapsed Intervertebral Disc Prolapsed Vertebral Disc A prolapsed intervertebral disc is commonly referred to as a slipped disc. This is actually rarely a "slipping" of the disc but a bulging out (herniation) of the inner part of the disc. Environmental factors include: Poor weight-lifting technique Smoking Occupations involving extended periods of sitting for example office work or taxi driving Trauma Age - "wear and tear" of the disc or "drying out" of the disc Spine and Disc As the name implies, the interverterbral discs are found between the vertebral bodies of the spine. The discs are rubber or jelly-like and act to cushion the spine when it bends.

Herniation occurs posteriorly or posterior-laterally beneath the posterior longitudinal ligament.

This can result in local oedema and pressure on the adjacent nerve root

Depending on the structures involved, different symptoms may be experienced: Pressure on ligament - Backache Pressure on dural envelope of nerve root - Sciatica Compression of nerve root - numbness, parasthesia and muscle weakness

Compression of Cauda equina - urinary retention [It is a medical emergency as damage may become irreversible if left untreated for too long!!!] The disc can herniate at any level in the spine, but it must commonly occurs in the lumbar region, specifically at L4/L5 and L5/S1.

Clinical Features1. The patient is typically a young and fit adult presenting with sudden onset back pain whilst lifting or stooping. 2. They are unable to straighten up due to severe pain.3. From the onset of the injury, the patient may present with: Backache Sciatica (characteristic pain in buttocks and lower limb) Paraesthesia or numbness in lower leg or foot Muscle weakness Urinary retention Backache and sciatica persists after the injury and is typically made worse by coughing or straining.Observation Sciatic Scoliosis - the patient may stand with a slight list to one side, increased during forward flexion

Range of back movements severely limited in all planesPalpation Tenderness in the midline of lower back Paravertebral muscle spasmSpecial Tests Straight Leg Raise (SLR) - Tests for herination atL4/L5 or L5/S1 discs.

This test is performed with the patient lying flat on their backs on the examination couch or bed.1. Raise one leg, keeping the knee joint completely straight, until pain is felt in the buttock, thigh or calf.2. Note the angle at which pain occurs.In normal circumstances pain is felt above 80-90 degrees. The test is positive when pain is felt between 30-70 degrees.3. Flexing the knee at this point will relieve buttock pain. Pressing on the popliteal nerve will reproduce the pain.4. Straighten the leg again and then lower the leg to below the angle where pain is felt. Dorsiflex the foot. If the pain is due tosciatica, this should reproduce the pain.

Patients with lumbar herniation will have a limited SLR and it will be painful on theaffectedside. 'Crossed Sciatic Tension' - Raising the unaffected leg may cause sciatic tension on the painful side. This may be observed but is not a common finding. Femoral Stretch Test -May be positive if nerve root of L3/4 is affected. This test is performed with the patient lying prone on the examination couch.1. Flex the knee to 90 degrees2. Extend the hip3. Pain is felt in the anterior thigh. Neurological Examination At the corresponding level of prolapse, you may find: Muscle weakness (later wasting) Diminished reflexes Sensory loss

L5 impairment weakness of big toe extension weakness of knee flexion sensory loss on the outer side of the foot sensory loss on the dorsum of the foot

S1 impairment weak plantar flexion weak eversion of the foot a depressed ankle jerk reflex Sensory loss along the lateral border of the foot.

Cauda equina syndrome Is aRED FLAG SYMPTOM. Causes saddle anaesthesia about the anus, perineum or genitals and loss of anal sphincter tone or faecal incontinence. Patients may present with difficulty micturating.

Imaging MRI is the most valuable method of imaging as it confirms the presence, level, size and extension of the disc herniation. An X-ray must be performed to rule out any bone pathology.

Differential Diagnosis1. Inflammatory disorders: Ankylosing Spondylitis causes severe and more generalised stiffness and typical x-ray changes. Tuberculosis of the spine (Potts Spine) will produce a raised ESR.2. Vertebral tumours- Cause constant pain. X-rays show bone destruction or pathological fracture3. Nerve tumours- may cause sciatica but pain is continuous. CT or MRI may delineate the lesions Treatment The majority of herniated discs will heal themselves within 6-8 weeks and do not require surgery. Management problems arise if pain lasts longer than 8 weeks. Non-Surgical or conservative managementmethods are usually tried first. These include: Patient education on body mechanics Physiotherapy Heat therapy Analgesics Anti-inflammatory drugs Oral or locally injected steroids Weight loss Smoking cessation Reduction - continuous bed rest and traction for 2 weeks Once non-surgical methods have failed,discectomy or micro discectomyis usually the treatment of choice.

Surgical managementThe indications for surgical management are:1. Cauda equina syndrome which does not clear up within 6 hours of starting bed-rest and traction(Medical emergency)2. Persistent pain and severely limited straight leg raising after 2 weeks of conservative management3. Neurological deterioration while under conservative management4. Frequently recurring attacks Rehabilitation Rehabilitation is essential for patients once they have recovered from acute disc rupture or disc removal. The patient is taught isometric exercises in order to reduce the strain on their back. Light work in resumed after 1 month and heavy work after 3 months. If the patient fails to recover fully, heavy lifting should be avoided all together.