Discectomy (including microdiscectomy)
The sciatic nerve and 'sciatica'
The longest nerve in the human body runs from the pelvic girdle at the base of the spine through the hip area and down the back of both legs. It is called the sciatic nerve. This nerve controls motor function in the legs and provides feeling to the thighs, legs and feet. The term 'sciatica' is often used to describe pain radiating along the path of this nerve. One of the most common causes of sciatica is a herniated (also known as a protruding or prolapsed) intervertebral disc. Surgical resection of the disc protrusion is a very successful treatment for this type of condition.
Disc herniation (or bulging) can be caused by degeneration of the discs that sit between vertebrae in the spinal column but also by injury sustained by high impact or repetitive strain on the back. This is sometimes referred to as a 'slipped disc'.
The diagram on the right shows a healthy disc between the adjacent vertebrae. When disc herniation occurs it can press on the nerves causing pain and discomfort. [image to be inserted]
The common symptoms are pain (which can vary from a mild ache to excruciating discomfort), numbness, muscle weakness and a tingling ('pins and needles') sensation. Occasionally when this occurs a patient can experience loss of sensation between the legs and around the buttocks or loss of control over bladder function. This is an emergency and if experiencing these symptoms an ambulance should be called.
The MRI scan here [image to be inserted] clearly shows a protrusion of disc material putting pressure on the nerves within the spinous process. In the lower part of the image there is a thinning of the nerve bundle represented by the pale strip immediately to the right of the vertebral bodies.
A consultant spinal surgeon will be able to determine whether there is likely to be a disc protrusion (or 'bulging') through careful examination. An MRI scan is undertaken to verify the extent of the disc protrusion and the level at which it is located. The consultant will then be able to discuss the treatment options available based on the diagnosis.
In mild cases of sciatica anti-inflammatory medication can be prescribed, especially if a patient suffers from any kind of contributing inflammatory disorder. It is often recommended that this is combined with physiotherapy and a guided exercise programme. Although perhaps seemingly counterintuitive, regular exercise is one of the best ways to combat chronic discomfort.
If the symptoms lie somewhere between mild and severe discomfort it may be recommended that a patient receive an epidural injection. The injection of corticosteroid medication into the affected region can assist in alleviating pain by reducing inflammation. This type of treatment is also only at its most effective when combined with a guided exercise and rehabilitation programme.
For severe pain or persistent symptoms surgery is a viable treatment option with a high success rate. Before a patient is admitted to hospital for disc surgery they will be asked to make a visit for a pre-operative assessment. This is a thorough examination and education process during which routine tests are carried out. It is also a very good opportunity for patients and their relatives to ask any questions they may have about the operation or preparing for it.
The surgeon will perform the operation under general anaesthetic through a small incision in the back and remove the portion of disc material that is pressing on the nerve(s). Microdiscectomy is carried out using a microscope or specialist binocular spectacles known as 'loops'. The success rates for discectomy (slightly larger incision) are roughly the same but post-operative recovery is usually quicker with a less invasive approach as used in microdiscectomy. A smaller incision also means a more cosmetically favourable outcome (less visible scarring).
Patients having a microdiscetomy will usually stay in hospital for a night following the operation but sometimes they are able to go home on the same day. This type of operation can often result in the immediate relief from all symptoms prior to surgery. Since discs continue to degenerate with age they may recur and a revision operation may be required in later life.
Rehabilitation and prevention
It is important to follow the exercises set out by the physiotherapists on an ongoing basis in order to maximise recovery after surgery and reduce the risk of recurrent disc problems as much as possible. It is also important that patients are familiar with the do's and don'ts to avoid overdoing activities in the immediate post-operative period up to the time of the follow up appointment with the consultant spinal surgeon (normally around 6 weeks after leaving hospital).
Exercise programmes are best tailored to individual patient's needs. The physiotherapist caring for each patient will offer outpatient appointments before being discharged from hospital.
For any enquiries please contact Mrs Mandy O'Sullivan who will endeavour to help you in any way possible.