(This is the section that explains the detail of the operation or procedure above and should be read in conjunction with the section called your back operation).

A lumbar decompression is performed for trapped nerves. The aim of the operation is to remove the compressive elements that are compressing the nerves of the spine. This may be bone, ligaments or even bits of discs. The usual situation is that the patient will present with progressive pain on standing and activity that gets better with rest.
They will also have progressive weakness and a feeling of their legs giving away under them. This is because the compression of the nerves lead to dysfunction in these nerves.

The aim of this procedure is to remove the compression with as minimal an approach as possible without causing the spine to become unstable. If the decompression needs to be severe, a fusion procedure might be required to stabilise the spine.
Spinal fusion can be bony alone or a combination of a bony fusion and instrumentation. Bony fusions are performed by placing pieces of bone over the back portion of the vertebraes and allowing it to grow together. This may be supplemented with screws that are placed through the pedicles (see the section on anatomy) of the vertebrae to keep everything together.
In operations where the nerves are being compressed by a disc protrusion and where the disc is sick, the whole disc is sometimes removed and replaced by a spacer. In these cases the vertebrae are stabilised by pedicle screws as well.

There are two main types, the TLIF or transforaminal interbody fusion and the PLIF or posterior lumbar interbody fusion. When performing a PLIF, the approach is from behind removing the whole lamina. In a TLIF the procedure is from the side of the vertebral canal and removes only part of one lamina and the joint that lies between adjacent vertebrae.

The main aim is to achieve a bony fusion. If this is not the case, then the operation is not a success and another operation might have to be performed in th e future. Bone growth is variable and depends on many factors and is different in different people. It is usually asumed that bone growth takes place from six weeks onwards and significant boen growth usually only occurs at about three to four months.

Interspinous fusions are where following decompression, the spine is stabilised by placing a spacer between the spinous processes. There are a variety of these spacers available in spinal surgery and your surgeon will use one of his preference. There will always be pictures and data available on the manufacturers website, so be sure to ask your surgeon about the name of the prosthesis (spacer) that he or she likes to use.

Ward care

You would be expected to get out of bed usually on the first or second day following surgery. You may usually walk around as much as you want depending on the stability of your spine. Your surgeon will advise you about this. You should be careful of sitting for too long or on a seat that is very low. This is to prevent you from placing too much strain on your lower back. Most surgeons recommend a duration of 30 minutes or less of sitting at a time. Many surgeons will ask their patients to wear a brace until the bony growth has taken place at six weeks or more. This can however be quite variable.

Discharge

You would normally be discharged between three days and a week after your operation. Staff at the hospital will take care of your follow-up consultation, analgesia to take home, sick certificate and wound care provisions in the post-operative period.

Rehabilitation

It is incredibly important to get a lot of rest and exercise following your surgery. Do not try to rush back to work. It is important to walk for exercise and also exercise in conjunction with the guidelines from your physiotherapist. You may perform activities only as prescribed by your health care provider. You should refrain from exercises that involve impact for at least three months. This would include jogging, mountain biking and equestrian pursuits.

Follow up

You will usually be seen after six weeks but will be seen earlier if there are any complications. In cases of spinal fusion you would usually undergo an X-ray of your back a few months after the operation to evaluate the bone growth between the two vertebrae.
It is important that this bony growth takes place; otherwise the operation might have to be repeated. It is important to realise that you will have to protect your back the rest of your life with good back habits. See the section on exercises to see what you can do to keep your back healthy.