Understanding of the back and disc prolapse : Disc prolapse also known as slipped disc is a medical condition affecting the spine in which a tear in the outer fibrous ring of the intervertebral disc allows the soft central portion to bulge out beyond the damaged outer ring.The spine is made up of many bones called vertebrae. These bones are roughly circular and between each vertebrae is a disc .The discs are made of strong rubber like tissue which allows the spine to be fairly flexible. Structurally intervertebral disc consist of an strong outer fibrous layer annulus fibrosus and a soft jelly like central portion known as nucleus pulposus. Strong ligaments are attached to the vertebrae which give extra support and strength to spine. Various muscles attached to the spine also provide strength and support to the spine. Disc prolapse most commonly occur in the lower part of the spine and over 90% of disc prolapsed occur between L4-L5 and L5-S1 intervertebral area.
What causes disc prolapse:
It is not clear why some people have a slipped disc and not others , even they do the same job or lifting the same sort of objects. It is probable that some people may have a weakness in the outer part of the affected disc and various things may trigger the inner softer part of the disc to prolapse through the weakened outer part. For example sneezing , awkward bending or heavy lifting in a awkward position may cause some extra pressure on the disc which may be sufficient to cause a prolapse.
Pathophysiology of disc herniation
Disc prolapse usually occurs in fit adult between the age 20-45 years.It is uncommon among very young and very old people . Disc herniation is usually due to age related degeneration of the outer layer the annulus fibrosus commonly superimposed by some episodes of excessive pressure .The physical stress which combines flexion and compression of back is the most proximate mechanism of disc prolapse. The sufferer has a severe back pain and is unable to straighten up. The disc prolapse may be protrusion, extrusion or sequestration depending on the degree of displacement of disc material . In case of protrusion there is posterior bulging of disc with some outer annuls intact. With total rupture fibrocartilagenous disc material extruded posteriorly and usually bulges to one or other side of the posterior longitudinal ligament which is known as extrusion.With a complete rupture part of the nucleus may sequestrate and lie free in the spinal canal .Prolapsed disc material may compress either nerve roots or spinal cord .Compression of nerve root causes loss of sensation and motor weakness related to that nerve along with radicular pain and compression of the spinal cord may result in paraplegia or quadriplegia depending on the segment involved.
Effect of large central disc prolapse : In some cases there is massive central disc prolapse with compression of the centrally placed sacral nerve roots producing bowel and bladder incontinence, perineal numbness and bilateral sciatica . Care shold be taken to deal with such a condition . It is a neurosurgical emergency needing urgent decompression otherwise there could be permanent life threatening disability. neurosurgical emergency. adjacent neural structure may be compressed .
Factors that may Increase the risk of disc prolapse:
Job involving a lot of lifts: People or workers who have to carry heavy load regularly or frequently on their back. Even sometime they carry too heavy load beyond their capacity, people performing such a job are at increased risk of disc prolapse.
A job involving a prolong sitting :Some job involves to work in sitting position even 12-16 hours daily This causes extra stress to back , specially if they do not maintain correct posture during sitting .Even the people working in office for a limited time if do not use chair of adequate height and angle are also at increased risk.
Weight bearing sports: Sportsman who perform weight bearing sports , when bear too excessive load unsuitable for his physical fitness and don’t maintain proper body posture are also at risk
Smoking :Smoking is detrimental for bone health. Smoking weakens the bone and accelerate age related degeneration of bone and disc.
Obesity: Obesity increase the risk both by the additional weight and metabolic effect of obesity on bone health.
Increasing age : Along with increasing age the bone and disc both component suffer from age related degenerative changes and losses their hydrophilic property, and these people suffers from disc prolapsed with minor trauma such as stooping ,trying to lifting weight .
Clinical Presentation : Pain the main presentation of disc prolapse and commonly preceded by multiple episodes of less severe low back pain or acute episode of weight lifting or severe back strain.
Symptom of herniated disc can vary depending on the location of herniation and the type of soft tissue that become involved. They can range from little or no pain if disc is the only tissue involved to severe and unrelenting pain that will radiate into the region served by affected nerve roots that are irritated or impinged by the herniated material. Pain become worse by coughing and straining.
2.Patient also suffer from paresthesia and numbness of the area supplied by involved the particular nerve.
3.There are sensory loss and motor weakness according to involved segment.
4.In case of massive central disc prolapsed , the patient may present with urinary and bowel incontinence, perineal numbness and there is bilateral sciatica and lower limb weakness
Management:
Conservative treatment: A trial of conservative treatment should be the initial treatment of all cases unless urgent operation is indicated
A) Bed rest and its new concept--when the patient suffers from an acute attack patient should be kept in bed with hip and knee slightly flexed. Continue with normal activities as soon as possible. This may not be possible at first if the pain is severe.
However move around as soon as possible and get back into normal activities as soon as the patient is able to do. Too much bed may result stiff joints and weak muscles. As a rule don’t do anything that causes a lot of pain during recovery from acute attack.
However patient have to accept some discomfort while he is trying to keep himself active. Setting a new goal each day may be a good idea – for example walking around the house on first day ,a walk to nearby shop next day.
In the past it was adviced for bed rest until pain subsides. It is now known that this practice was wrong , patient is likely to recover more quickly and less likely to develop persistent or chronic back pain if the patient is active rather than rest a lot during an acute episode of back pain .
Likely advice to sleep in a firm mattress have not proved no evidence that sleeping in the most naturally comfortable position on whatever the most comfortable surface gives a better outcome .
B) Use of anti-inflammatory analgesic: Adequate analgesic and hot compression to back are helpful in alleviating pain,
C) Physical therapy or exercise: Some of the first therapies such as ultrasound, electric stimulation, hot packs and cold packs to reduce pain and muscle spasm which will make it easier to start an exercise programme. Traction may also provide limited pain relief for some patient.
D) Reduction : Continuous bed rest and traction for 2 weeks may reduce an acute herniation.
E) Removal of the disc
material: Chemonucleolysis of nucleus pulposus by percutaneous injection of a proteolytic enzyme though excellent theoretically but less effective potentially dangerous than surgical removal.
F) Rehabilitation : Rehabilitation is a fundamental step in managing disc prolapsed patient either following conservative treatment or after surgery patient have to take care his back by maintaining
correct posture during sitting , walking and other day to day activities,perform regular back exercise to strengthen back muscles.
Surgical Treatment:
Surgical removal of intervertebral disc is indicated
1. when there is progressive neurological deterioration inspite of conservative treatment,
2.If there is persistent pain and sciatic tension after 2-3 weeks of conservative treatment.
3.Recurrent pain and disability interrupting normal life or day today activities.
4.In case of cauda equina syndrome.
Prevention Disc Prolapse: Keeping the spine healthy so that age related bone degeneration slows along with maintenance of good posture and careful weight lifting helpful in prevention.
Exercise: Regular exercise can slow 
the age related deterioration of the intervertebral disc. It can also keep the supporting muscles of the back strong and supple.
Maintain a standard weight: Overweight put extra strain and pressure on the back. So maintaining a healthy standard weight help to keep off the extra load on back.
Lifting: Maintaining correct body posture and technique while lifting is important . Avoid weight lifting beyond one’s capacity.
Posture: Maintaining good posture is an important step for prevention of disc prolapse.
Sitting: When sitting or driving for a long time, the seat should be supportive and comfortable, while sitting on computer for a prolong time or job involving using a computer, take regular breaks away from the computer screen . Make sure that computer screen is at eye level and directly in front.
Walk or stand with head and shoulder slightly back and while sitting at a desk , the chair should be of correct height so that the feet should be able to rest flat on the floor with knees bent at 90 degrees.