Dr. Kevin Yip

Dr Kevin Yip
Orthopaedic Surgeon
MBBS(UK), FRCS(EDIN), FAM(SING), FHKCOS(ORTHO)

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Sciatica, Herniated Disk (‘Slipped Disk’)

Pain that radiates from the lower back down one or other leg is known as sciatica. It is often exacerbated by exertion, coughing, sneezing, or straining. One of its most common causes is a ‘slipped disk’ which exerts pressure on one of the roots of the sciatic nerve, and it can also be triggered by a temporary local trapping or straining of the nerve or its roots. Rarer causes include tumors, bony deposits, spondylolysis, spondylolisthesis, and infections which can affect the sciatic nerve throughout its course.

The intervertebral disks are composed of a connective tissue ring and a core of a pulpy, semifluid substance. Slipped disks often show signs of degenerative changes, even in relatively young individuals. Cracks form in the connective tissue ring of a disk, allowing the pulpy substance to seep through and cause pressure on the adjacent nerve roots. The prime cause of a slipped disk is bending forwards and to the side to lift a heavy object. Athletes who suffer slipped disks have often had previous attacks of acute lumbago. Depending on where the slipped disk is located in relation to the nerve root, different syndromes occur:
– L4 syndrome when the nerve root adjacent to the disk between the third and the fourth lumbar vertebrae is affected;
– L5 syndrome when the nerve root adjacent to the disk between the fourth and fifth lumbar vertebrae is affected;
– S1 syndrome when the nerve root adjacent to the disk between the fifth lumbar vertebra and the first sacral vertebra is affected.

Symptoms

As a rule, the S1 syndrome affects people up to about 40 years of age, while the L5 syndrome is more common in older individuals. Each syndrome has a characteristic pain radiation pattern and affects
sensation, reflexes, and muscle power.

A combination of lumbago and sciatica occurs in which pain is felt mainly in the lumbar region but also radiates into one leg and increases on exertion. There may be numbness in the area of distribution of the
nerve, weakness in the leg, and diminution of the reflexes. The pain can be triggered by coughing or straining and can be so severe that the lumbar region becomes locked into a position of lateral flexion
(scoliosis).

Diagnosis

– The diagnosis is confirmed by the characteristic history of the pain.
– Examination of the spine may reveal a scoliosis caused by strong muscular contraction in the lumbar region.
– Mobility is impaired and the musculature is tender and tense.
– Straight-leg raising (Lasègue test): that is, with the patient lying supine. The passively extended leg is raised by the examiner, and at some point the patient experiences pain radiating down the leg.
– Neurological examination may reveal diminished reflexes, weakness or paralysis, and impaired sensation.
– In serious cases, disturbance of the nerve supply to the bladder results in difficulty in passing urine. If this occurs, a doctor should be consulted immediately.
– A diagnosis of slipped, herniated disk is confirmed by a CT or MRI scan.

The athlete should:
– rest from painful activities; the psoas position may help. As rest causes rapid wasting of the back muscles, special training exercises should be started as soon as possible;
– apply local heat and use a heat retainer.

Treatment

The doctor may:
– advise rest, and increase of activity as tolerated for 8–12 weeks;
– prescribe analgesics, anti-inflammatory medication, or muscle relaxants;
– start gentle traction treatment under the supervision of a physiotherapist when the condition has passed its acute stage;
– prescribe transcutaneous nerve stimulation in persistent cases;
– perform emergency surgery in cases of bladder function impairment;
– operate when acute pain persists in spite of analgesic drugs, when paralysis occurs, and/or when a disabling postural defect resulting from reflex muscle spasm fails to correct itself or deteriorates further.
A preoperative CT or MRI scan is needed so that the surgeon can identify and locate the slipped disk.

Healing and complications

– Most individuals who suffer from a slipped disk recover gradually over time with rest and exercises alone.
– Following surgery, depending on the technique and extent of injury, the athlete can return to active sport or heavy work in 6–10 weeks.
– The results of surgery are good: 95% of patients make a complete recovery.

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