Cevrvical and lumbar spondylosis (degeneration) are very common conditions. Whilst much can be done to alleviate symptoms with physical therapies and injections, more advanced cases and those with nerve compression are best treated by surgery. This aims to decompress the nerves whilst preserving as much normal function as possible. Minimal acces techniques also reduce trauma to the surrounding muscles, joints and ligaments. Many spinal tumours can be fully removed by surgery with excellent longterm control.
Disc Prolapse (Slipped Discs)
Wear and tear results in the gradual loss of fluid from the centre of the intervertebral disc, with such changes frequently visible on MRI scans of healthy adults from their 20's. Should the disc wall (annulus) give way the loose disc centre may rupture into the spinal canal. This most often causes sciatica due to pressure on the nerve root that is passing across the disc. More severe ruptures can damage the nerves resulting in muscle weakness, numbness or even loss of bladder and bowel control (cauda equina syndrome). Whilst some cases will settle rapidly many require surgery to decompress the nerve, relieve the pain and maximise functional recovery.
Disc surgery is performed from the back of the patient and is normally performed via a short (4cm) incision, using a microscope to dissect the prolapse away from the nerve and a drill to remove and rough edges of bone (microdiscectomy and undercutting facetectomy).
Cervical disc prolapses may compress the spinal cord as well as the exiting root resulting in permanent damage to the cord. Surgical decompression can halt this damage and allow for maximum neurological recovery. As the spinal cord lies behind the disc it is usually safest to operate from the front of the neck (an Anterior Cervical Decompression). In experienced hands this is a very straightforward procedure with low risks and very rapid recovery
Technical Advances in Cervical Disc Surgery
It is now well established practice to insert some form of spacer into the disc space after cervical discectomy and nerve root decompression. The rationale for this is that the spacer can restore the disc height thereby restoring the natural curvature of the neck and also opens up the nerve root canals further decompressing the roots. More recently prosthetic disc replacements have become available that can achieve the same advantages as interbody cages but also retain or restore normal motion to the disc. This seems to give the best pain relief, range of motion and should avoid many of the problems with adjacent level degeneration. The latter is accelerated wear seen in the discs above and below a fused level. The particular implant used however needs careful selections as not all the available implants have the same design and security.
Spinal Fusion (Lumbar)
Abnormal or excessive mobility of the spine causes pain and poses a threat to the nerves or spinal cord and requires surgical correction. This involves three key stages - Decompression, Fixation and Fusion. The nerves are first decompressed by removing excess bone and ligament, then metalwork is inserted (usually screws and rods) to hold the bones in alignment and finally bone graft or bone substitute applied to encourage gradual union of the bones. Once fusion has occurred the metalwork becomes redundant. The implants used for fusion surgery have developed rapidly in recent years. They are mostly made from Titanium so are MRI-compatible and are precision engineered for maximum strength and adaptability. Spinal fusion surgery has therefore become much simpler and more effective. It remains however a major trauma that takes 4-6 weeks to recover from and fusion make take many months to solidify. There are less invasive techniques that can minimise the trauma without compromising the surgical aims.
Minimal Access Spinal Surgery
The latest evolution in spinal implants is the development of screws and rods that can be inserted either through a minimal access approach or percutaneously using x-ray or navigation guidance. These are employed wherever possible to reduce trauma to surrounding tissues, minimise post-operative pain and maintain normal mobility. The recovery time following surgery can thus be reduced without sacrificing effectiveness.