Nerve compression is common, but most cases settle without an operation. Here is how I decide when surgery is genuinely needed.
If you have been told you have nerve compression in your spine, whether from a slipped disc, spinal stenosis or another condition, the natural next question is whether you need an operation. It is one of the most common questions I am asked in clinic, and the answer is reassuring more often than people expect.
What causes nerve compression
The common causes are:
- A herniated disc pinching the nerve
- Spinal stenosis, usually from thickening of the ligaments at the back of the spine, changes in the facet joints, or bony spurs forming
Less commonly, compression can result from tumours or fractures of the spine.
Why surgery is usually not needed
With the common causes, most people do not need an operation. Nerves are more resilient than patients imagine and can tolerate a degree of compression.
The pain itself, whether sciatica travelling down the leg from the lumbar spine or pain down the arm from the neck, comes largely from the inflammation that occurs when the nerve is first compressed. That inflammation usually settles with time, often within a few days to a few weeks. Meanwhile, the body sets about breaking down and dissolving the herniated fragment of disc, giving the nerve more room.
For that reason, pain alone is rarely an absolute reason to operate.
The same principle applies to fractures. In someone with osteoporosis or osteopenia, where the bone density is poor, most fractures heal with conservative management, sometimes simply a brace worn around the waist for a few weeks, provided there are no symptoms of nerve compression such as leg pain, weakness or loss of function.
When I do consider surgery
When pain fails to settle. For pain radiating down the leg from a trapped nerve in the lumbar spine, if it has not improved within a few weeks of conservative measures such as painkillers, physiotherapy or a spinal injection, then a microdiscectomy to shave away the offending disc can be very effective. The same applies to a trapped nerve in the neck causing arm pain: a small procedure to free the nerve works well once conservative measures have failed.
With stenosis, I usually try physiotherapy first. Injections tend not to work as well here, though various measures to stretch the ligaments can help. If those fail, a minimally invasive operation to remove some of the thickened ligament can relieve the leg pain that comes on with walking.
When function is being lost. This is the more pressing consideration. If a compressed nerve in the lumbar spine is causing weakness in the leg or ankle, that is an indication for fairly urgent surgery to preserve and restore that function. The same applies to weakness in the arm from a trapped nerve in the neck.
If the spinal cord itself is compressed in the neck, the consequences are broader. The cord carries messages between the brain and the body, and compression can cause weakness in both the arms and legs, poor coordination of the hands, and loss of balance.
Cauda equina syndrome is a genuine emergency. Loss of bladder or bowel control, particularly alongside pain or numbness in both legs or numbness in the genital region, needs immediate assessment. Timing here is critical.
Certain tumours. Tumours within the lining of the spinal canal, known as intradural tumours, are a different matter. Even when they are causing no pain or significant symptoms, a sizeable one is likely to keep growing and eventually compress the nerves. I therefore tend to operate on these.
Treat the patient, not the scan
I say this often, and it matters here. Wear-and-tear findings such as disc herniation and stenosis are common on scans of people with no symptoms at all. A scan finding is not automatically the cause of your pain.
Good decisions come from tying the whole picture together: a careful history, a proper examination, and the imaging considered alongside both. Often the most useful thing I can do is give clinical direction to a team, a physiotherapist and a pain specialist for instance, to get on top of the symptoms and see whether things resolve on their own.
The key takeaway
Much of this comes down to timing. Operating too soon means not giving your body the chance to recover, which it frequently will. Leaving it too late, where function is already being lost, means there is less to preserve or regain.
Nerve compression on a scan is common. Nerve compression that needs surgery is far less so.
