Spinal fusion is the traditional method of stabilizing the spine and can be carried out using an anterior approach, a posterior approach, both, or sometimes from below the sacrum in a fairly novel procedure called AxiaLIF. Bone grafts are usually used during a spinal fusion procedure and this may involve the harvesting of a portion of bone from the patient’s hip to use in the fusion. Alternatively, cadaverous bone can be used from a bone bank, or a morphogenic bone protein (synthetic substance) can be used to stimulate the growth of new bone. An autograft (using the patient’s own bone) is considered the best option in most cases, unless a secondary condition rules out using the hip bone. In cases where arthritis is present in the hip bone in addition to the spondylosis, the patient may be better served by using donated bone.
To achieve a solid spinal fusion between the bones and the grafts can take months, or even years, with some significant restrictions in physical activity during the first few months as the fusion begins. The surgeon is likely to make use of instrumentation to stabilize the spine as the fusion takes place and also to hold the graft in place. Screws, rods, wires, cables, and metal plates are often used and can be extremely effective in facilitating a solid fusion. Spinal fusion may also help to restore lost intervertebral height which can effectively reduce symptoms such as sciatica and other neurological pain. If a laminectomy is performed as part of decompression back surgery then spinal fusion is likely to be considered as this operation can destabilize the spine. In general, the more levels of the spine that are operated on the more likely the spine is to need a fusion procedure to keep it stable.
There are several things that can increase the risk of pseudoarthrosis after spinal fusion surgery, including smoking, and the use of NSAIDs by the patient. Patients are advised to quit smoking well in advance of any back surgery, but particularly fusion, as rates of success drop rapidly in the presence of nicotine and other substances in tobacco which impair bone mineralization and growth. Some NSAIDs also lessen the rate of new bone growth and are usually advised against in the immediate period following fusion surgery for spondylosis. Narcotic medication may be given instead to help patients manage their pain following invasive back surgery, although these drugs can be addictive and require careful monitoring.
Non-Fusion Stabilization Back Surgery for Spondylosis
Spinal fusion used to be the only real option for patients with spondylosis looking to stabilize the spine but innovation in the field of back surgery means that other options are now available. The X-Stop device has been implanted in thousands of patients with back pain due to compression and spinal degeneration and can effectively relieve spinal nerve compression due to instability of the spine. The device is contraindicated in those for whom spinous process fracture, or other type of spinal fracture, may be thought likely. The X-Stop interspinous process device is inserted during a minimally invasive procedure, often performed in an outpatient clinic, and can achieve, even when standing, the type of decompression and relief experienced by those with sciatica when bending forward.
These interspinous process devices can effectively restore intervertebral height and reduce compression on the spinal nerves by preventing a patient from bending too far backwards due to spinal instability. The range of motion of the spine is otherwise largely unaffected which makes it preferable for many to spinal fusion. If problems exist with joint degeneration or disc degeneration at other levels then the X-Stop may not be appropriate, however, with spinal fusion more likely to achieve better results for the patient.
An alternative type of surgery is Dynamic Stabilization, where the surgeon attaches spinal implants to the pedicles of the vertebrae in order to provide a tension band and support to the spine. The procedure is performed using an implant such as Dynesys, which allows the spine to remain mobile, but supported, and is therefore advantageous in maintaining flexibility that is lost with many fusion procedures.