Slipped Disc (Cervical and Lumbar)

SLIPPED DISC (SCIATICA)

Aetiology

The most common cause of sciatica is a lumbar disc prolapsed causing nerve root compression. Sciatica-type pain may also occur as a result of bony compression of the nerve root, usually by an osteophyte, and is often associated with lumbar canal stenosis or spondylolisthesis. Narrowing of the ‘lateral recess’ of the spinal canal may also occur in conjunction with lumbar canal stenosis, and may cause compression of a nerve root. Sciatica may occasionally be caused by tumours of the cauda equine or by pelvic tumours, such as spread from carcinoma of the rectum.

Patient assessment

The patient suffering from sciatica will be in obvious discomfort, which will be reflected by movements and posture when lying supine.

The patient lies tilted, usually to the side opposite to the sciatica, with the affected hip and knee slightly flexed taking pressure off the stretched nerve. The pain is worse on movement, coughing, sneezing or straining. Although back pain may be present, the important feature is the pain which radiates down the leg in the distribution of the affected nerve. The pain usually radiates into the buttock, along the posterlateral aspect of the thigh and calf into the foot (S1 nerve root). An L3/4 disc herniation may produce pain in the posterior thigh but, as with an L2/3 disc prolapse, the pain is frequently along the anterior aspect of the lower leg. Depending on the degree of nerve root compression, the patient may complain of sensory disturbance such as numbness or tingling in the leg or foot, and weakness may be present. The history must include and assessments of sphincter function, as a large disc prolapse may cause cauda equine compression.

Management

Most patients with sciatica achieve good pain relief with simple conservative treatment and less than 20% will require surgery. The likelihood of symptomatic relief workout surgery is related to the pathology of the disc prolapse. A ‘bulging’ disc is likely to settle with simple conservative measures, but sciatica due to a nucleus pulposus that has herniated out of the disc space and ‘sequestrated’ outside the annulus will probably need surgery for satisfactory relief of symptoms.

Conservative treatment

Most patients achieve good pain relief following strict bed rest, usually for a period of about 10 days, and the use of simple analgesic agents and non-steroidal anti-inflammatory medication.

Indications for surgery

Pain

This most common indication for surgery in patients with disc prolapse is pain in the following situations:

Incapacitating pain despite 10 days of strict bed rest, continuing episodes of recurrent pain when mobilizing despite adequate relief with bed rest. In this group of patients physiotherapy and a limited trail of a spinal brace might be tried, but they usually have only limited success.

Neurological deficit

A significant weakness or increasing amount of weakness is an indication for early investigation and surgery.

Central disc prolapse

Patients with bilateral sciatica or other features indicating a central disc prolapse, such as sphincter disturbance and diminished perineal sensation, should be investigated promptly. An acute central disc prolapse may lead to acute, severe, irreversible cauda equine compression and should be investigated and treated as an emergency.

Treatment

Surgery is indicated if the clinical features suggest that a prolapsed disc is the cause of sciatica or symptoms.

Surgery involves a small operation and patient is discharged within 24 hours from the hospital. Patient is allowed to walk after 4 hours of surgery and they are allowed to go back to work after 2 weeks.