What is lumbar decompression?
A lumbar decompression involves removal of the bone and ligaments that are causing compression of the spinal nerves in the lower back (spinal stenosis). The classical symptoms are when there is pain on walking, in the calves or buttocks.
Usually, back pain is not a feature, and the pain is related to standing or walking and relieved with rest. Sitting or lying improves the pain. Bending forward, such as with a shopping trolley also improves the pain. Occasionally the pain is almost entirely in one leg and typically this is caused by the nerves on one side being compressed more than the other side.
Surgery is usually aimed at improving pain, and neurological symptoms such as weakness and sensation.
When is lumbar decompression recommended?
Symptoms in the vast manjority patients will settle with time and as long as improvements are noted at 6 weeks, there is minimal or no weakness and the pain is not excruciating, then waiting and continuing with conservative therapy is reasonable.
However, If there is evidence of severe weakness, or if the pain in the leg is so severe that narcotic painkillers are not controlling it, then surgery may be offered.
Surgery is also be an option if there are problems with the nerves that supply the bladder or bowel (ie; an inability to pass urine, numbness in the crotch area or buttocks when passing urine). This situation usually necessitates emergent or early surgery.
How is the surgery carried out?
Lumbar decompression is done under general anaesthesia, and antibiotics are given. To summarise the operation:
- the procedure involves the removal of the spinous processes with a variety of 'biting' instruments and small, high speed drills. At the end of the decompression, the nerve should be free
- the procedure can take 1-2 hours depending upon the number of spine segments that require decompression
- a drain may be inserted into the back, and is removed after 24 hours
- you will be encouraged to mobilize after 24 hours or when you are feeling better
- you will be required to wear leg stockings to prevent leg clots (deep vein thrombosis)
- you will be given appropriate advise and information from the physiotherapist about exercises
What is the expected outcome?
In most patients the likelihood of good/excellent relief of leg pain is approximately 80%, but this may vary depending on duration of symptoms and associated medical conditions such as diabetes. Other outcomes of lumbar decompressions surgery are:
- numbness is slow to recover and may persist particularly if you have had symptoms for a long period prior to the surgery
- weakness may also take time to recover although this can at times be incomplete particularly if the weakness was severe and prolonged before surgery
- pins and needles usually start to improve immediately
- often, there is some degree of back pain following surgery. If you had significant back pain prior to surgery it's unlikely to be made better by the surgery as this is NOT an operation for back pain
- occasionally you may experience resurgence in pain, which is often transient following initial surgery, which may reflect nerve root irritation and the fact that you have increased your activity level. This is treated in most cases with painkillers. Occasionally, an epidural steroid is given to control pain but this is uncommon
Following surgery, what is the recovery like?
- patients who have a lumbar decompression are typically in hospital for 3-7 nights
- after 3 –6 weeks, you can drive and should be able to return to light work
- you will encouraged to walk ½ to 1 mile a day
- you may need regular pain killers for several weeks after surgery
- expect up to one year for recovery, as ‘nerve recovery’ can be quite slow particularly bearing in mind that they had been compressed for such a long time
- it's important to remember that the back is not normal after decompressive surgery and that care needs to be taken in the future. Bending, lifting and twisting need to be avoided as these activities ultimately may have precipitated the initial event, particularly for the first 3 months
- good back care is the rule for life!
- no surgeon can guarantee totally risk-free surgery or a 100% good outcome
What are the potential risks and side effects?
In general, majority of patients are happy with the outcome with at least 80% expected good result. Specific risks of surgery, in the order of 1-5%, include:
- infection (less than 1% risk)
- deep vein thrombosis (less than 1% risk)
- disc recurrence (approximately 5% risk)
- neural injury/dural tear (1-5%) – usually transient bruising of nerve which settles; very rare for permanent weakness to occur
- cauda equina syndrome (less than 1%) – this can be due to development of a clot. This causes weakness and bladder symptoms and will require return to theatre for removal of the clot
- increased back pain – this tends to be transient, and settles down
- burning pain- this often reflects damage to the nerve at the microscopic level from the chronic severe compression
Lumbar decompression is a good operation for leg and buttock pain, weakness, numbness, pins & needles but NOT back pain. In general, if symptoms still persist in a way that interferes with a patient’s quality of life and don't respond to conservative/simpler treatment, then surgery is a definite treatment option.
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