(This is the section that explains the detail of the operation or procedure above and should be read in conjunction with the section Your Neck Operation).
There are several reasons for performing a posterior neck fusion. Generally, this operation is performed for instability of the cervical spine (neck). The instability could be the result of trauma, but it could also be the result of extensive surgery that was needed to decompress spinal nerves. In other cases, the cervical spine has become unstable due to a degenerative condition such as rheumatoid arthritis.
There are many different techniques depending on the preference of the specialist and on the pathology that needs to be treated. There are techniques where wires are used to attach the spinous processes or the facet joints (see the section Anatomy of the Spine) to each other to stabilise the spine. Other techniques involve the use of metal clamps that hook on to the laminae. More robust fusions are made possible by putting screws into the lateral mass. This is the bit of bone that supports the facet joints and contains the tunnel through which the vertebral artery runs. Another technique is to put screws into the pedicles (see the section Anatomy of the Spine) of the cervical vertebrae.
It is frequently necessary to decompress the nerves before the fusion. See the section Cervical Laminoplasty and Laminectomy for a description of this part of the operation.
When undergoing this operation, you will be lying on your stomach and the specialist will be operating from the back of your neck. Your skin will be sterilised and the area will be covered with sterile drapes. An incision will be made and the tissue carefully separated up to the spine.
At this point a decompression procedure may or may not be performed by removing the laminae (see the chapter Cervical Laminoplasty and Laminectomy). The appropriate fusion technique will then be carried out. See the illustrations on the following pages for a description of the different techniques. In cervical fusion operations it is important that the instrumentation that is used should stabilise and correct the alignment of the spine and also that the bone being used as a bone graft, does in fact grow, and form a proper fusion. This is exactly the case as in lumbar fusion operations.
The main aim with a fusion operation is to achieve a bony fusion between the vertebrae concerned. If this is not the case, then the operation is not a success and another operation might have to be performed in the future. Bone growth is variable and depends on many factors and is different in different people. It is usually assumed that bone growth takes place from six weeks onwards and significant bone growth usually only occurs at about three to four months.
A drainage pipe will be placed in the wound and connected to a reservoir before the wound is closed. This will allow all excess blood to drain away. After the operation, you will be taken to the recovery room to recover from your anaesthetic. You will then be transferred to the ward or the high care unit. You may mobilise after the operation as soon as your specialist allows this and it will most probably be on the day following your operation. The nursing staff will administer analgesics for post-operative pain.
These drawings demonstrate a fusion between the thoracic and cervical spine. There are many different variations of posterior (from behind) cervical fusions and different types of instrumentation. In all cases the instrumentation is attached to the vertebrae with screws or hooks.
The top drawing demonstrates the position in which the patient is placed to allow neck flexion. This way, the back of the neck is easily accessed. Specific bony landmarks are then identified and screws inserted as demonstrated in the bottom two drawings.
These drawings demonstrate how the screws are placed in the vertebrae and then connected up with rods that are secured to keep the spine stable. After the screws and rods have been secured, bone is packed on top of the laminae to enhance bone growth between the vertebrae, leading to a fusion. The bone would normally be harvested from your body - the rim of the hip bone is a favourite donor area. Artificial bone may also be used. In the case above, a fusion has been performed between the cervical and the thoracic spine.
In the ward you may walk around freely. A neck brace or collar may be prescribed to keep the spine stable in the direct post-operative period and you may even have to wear it for several months.
You will usually be seen by the physiotherapist who will demonstrate the appropriate neck exercises. The drainage pipe in your neck will be removed in the days following your operation.
You would normally be discharged within the week after surgery with analgesics to take home. A painful throat and even some hoarseness can be quite common and usually only lasts a few days. Wound care will be discussed with you by the nursing staff or your specialist.
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 normal activities and should only wear a neck brace or collar if your specialist prescribes it. You should refrain from exercises that involve impact, for six to nine months. This would include jogging, mountain biking and equestrian pursuits.
Routinely you will receive a date for your follow-up appointment with your specialist. This may vary from anything between two and six weeks, but you will be seen earlier if there are any complications. You would usually undergo an X-ray of your neck 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.
Remember to always protect your neck and apply good neck habits.