Lumbar spinal surgery is used by a spinal surgeon to treat three main conditions; leg pain, back pain or deformity. Clearly it can be used to treat a combination of these.
A spinal surgeon will nearly always consider surgery as the last option behind the physical therapies, physiotherapy, osteopathy and chiropractic. Non-operative pain control of injection techniques such as caudal epidurals and facet joint injections to give a ‘window of opportunity’ to allow further physical therapy are considered next.
The time when spinal surgery is considered before these therapies is when there is a serious pathology such as tumour or infection or when there is serious concern about nerve function such as in cauda equina syndrome.
This article on spinal surgery is written by Andrew Quaile, Consultant Spinal and Orthopaedic Surgeon, Hampshire and Surrey.
Leg pain surgery is largely concerned with removing anything that is irritating a nerve. These operations are discectomies or decompressions and are non-controversial and traditional. Operations for back pain are newer and are often combined with a discectomy or decompression. Deformity surgery is more extensive and not discussed here. There is increasing interest in keyhole or percutaneous techniques for nerve pain. These have to be matched against the more traditional techniques to see if they are worthwhile. Their most obvious advantage is the faster recovery time and reduced collateral damage. Currently, they are not quite as successful as a micro or mini discectomy in reducing sciatica.
The traditional operation for back pain is a fusion. This is still the case for painful deformities such as Spondylolisthesis. The fusion, which is achieved with a bone graft, is stabilised by rods and screws made of titanium. These have the role of a scaffold to hold things together whilst the fusion takes and removes the need for an external brace. This scaffold can be enhanced by the use of cages made of plastic which are inserted into the disc space to be fused. These are hollow and also contain bone graft to allow a fusion. The cages are capable of taking the load through the disc space therefore removing pain caused by compressing the discs. The downside of a fusion is potential increased stiffness in the spine and possible increased pressure on the level above. This can lead to the failure of the disc above the fusion.
To get away from a fusion, especially in a young person without deformity, devices have been made which act as shock absorbers to load share and reduce the strain on a painful disc or joint without removing it. Modern examples of these are the Dynesis system and the Wallis ligament. They differ in their design and means of attachment. They both allow a nerve decompression to be carried out as well. The surgery to insert these devices is similar to that of a fusion for which more minimal access techniques have been developed. That is to say for all types of spinal surgery the muscle dissection has been reduced to be as small as possible to allow a faster recovery and to promote better long-term function of the back. These devices can also be used to protect a worn disc above a fusion to reduce the tendency to long-term wear as a consequence of the increased stiffness of a fusion.
In patients with stenosis, a narrowing of the nerve canal, the old approach was a laminectomy to remove the roof of bone off the spinal canal. More modern devices such as the X-Stop or Flexis allow an indirect decompression of the nerves by pushing apart the laminae. This distraction of the bony elements creates more room for the nerves. The advantage is these avoid bone removal and any likelihood of nerve damage as no surgery is done close to the nerves in the spinal canal.
The final advance is the ability to fuse the lowest disc via a small incision at the coccyx. The disc is removed, fused and held via a bolt inserted via a tube inserted under x-ray control. The advantage is a much shorter hospitalisation time, reduced collateral damage and quicker recovery. It should be noted that this technique is still a fusion and should be accompanied by some form of screw technique to support it from behind.