Cervical Spine

 Disc Degeneration in the Cervical Spine

The intervertebral discs in the cervical spine in the neck can undergo the same process of degeneration as occurs in the other regions of the spine. 

The breakdown of the molecular structure of the central nucleus pulposis causes it to lose water with the result that the disc collapses to a greater or lesser extent.  

Continuing degeneration leads, as in the lumbar spine, to secondary degenerative changes in the facet joint and ligaments about the affected level. The vertebrae respond by throwing out bony processes over the degenerate disc between them, thought to be the body’s way of stabilising the area. In addition the small synovial uncinate and facet joints between the vertebrae may become arthritic. The ultimate effect of these changes is the development of a form of arthritis between the vertebrae called ‘spondylosis’.

One of the consequences of this spondylosis is that the intervertebral disc bulges, or may prolapse, backward into the spinal canal. In this region the spinal cord occupies a large proportion of the spinal canal and there is little room to accommodate the intrusion of the disc into the canal. There is therefore a greater likelihood of neurological involvement.

As in the lumbar region, the impingement of the degenerating disc on the nerves causes pain in the neck and, frequently, pain radiating down one or other arm. As with radicular pain in the legs, the pain is often associated with a feeling of heaviness in the arms and ‘pins and needles’ in the hands. The affected individual may find that he, or she, drops items because of the weakness in their hands.

Treatment of Cervical degeneration

Conservative – in most instances, the symptoms of neck and arm pain arising as the result of degeneration in the cervical spine are initially treated by way of a series of non-operative methods. These methods can include:

• Analgesic preparations, especially the use of non-steroidal anti-inflammatory tablets. There is always a certain amount of inflammation associated with cervical spondylosis and an effective non-steroidal anti-inflammatory tablet can go a long way in relieving the pain from the condition.

• Physiotherapy to the neck is often of assistance. This may include various exercises to the neck as well as traction to the cervical spine. The traction, by separating the arthritic bones, can produce some relief of pain.

• Injection of ‘trigger spots’. There is a complex inter-reaction between the development of fibromyalgic ‘trigger spots’ which typically occur at the base of the neck, between the shoulder blades, and about the shoulders and a variety of conditions which may set them off. Cervical spondylosis is one of the causes of these ‘trigger spots’. The pain generated by these areas is often intense and prolonged, and is frequently more uncomfortable than any pain arising from the spine itself.

• Use of a cervical collar, either soft or stiff, can sometimes relieve the discomfort by supporting and stabilising the neck.
• Adjusting or changing the pillows, used while sleeping, may also be of assistance.
• Operative – If conservative measures are unsatisfactory the only other option for pain relief may be one of the forms of surgery. As with degeneration in the lumbar spine, there are several surgical options. The procedure used will depend upon the exact form which the degeneration takes, whether there are neurological symptoms, the degree of damage which is present in the cervical spine, and individual preferences.

 

Simple discectomy

If the prolapsed disc is small, and there are no significant secondary degenerative changes in the spine, there may be an indication for a simple decompression of the affected disc; an analogous procedure to the simple discectomy in the lumbar spine. This is usually performed through and anterior approach in the neck. There are a few centres where this form of discectomy is performed percutaneously using fine probes but the results are not uniform and this form of surgery is still viewed with circumspection.

Discectomy with Stabilisation

Where the degeneration of the intervertebral disc is prolonged and severe, secondary arthritic changes may take place in the small synovial uncinate and facet joints between the vertebrae. This, combined with disc prolapse and thickening of the ligaments, leads to compression of the spinal cord and the exiting nerve roots. The result is intractable pain in the neck which radiates into one or both the arms and hands.

 

In this instance a simple discectomy relieves the pressure on the nerves at the affected level. This alleviates the pain and weakness in the arms but may do little to relieve the discomfort felt in the neck as there will be continuing movement between the arthritic joints. In this case, in addition to the ‘discectomy’ it is necessary to stabilise the affected vertebrae. This is usually done by the insertion of a quantity of bone, or bone substitute substance, or a ‘cage’ which holds the bone graft, between the vertebrae. Further support to these implants may be given, if necessary, by screwing a supporting plate onto the front of the vertebral bodies to hold everything firmly in place. By eliminating the movement between the affected vertebrae the pain from the arthritic joints is removed.

Non-fusion techniques

Cervical disc replacements

While rigid fusion of the cervical spine serves to reduce the pain from a severe spondylosis (degeneration) the loss of movement at the affected levels is unsatisfactory and a cause of concern to some. The rigidity which it engenders is not physiological and it has been shown that fusion of an intervertebral level can lead to a compensatory increase of the movement at the adjacent levels of the spine. This, in turn puts an increased strain on these parts of the spine and it is felt that there is an increased chance of degeneration taking place at these sites.

Disc arthroplasty is a treatment which has been recently developed for patients with disc degeneration in the neck. Its theoretical advantages are that insertion of the artificial disc maintains the physiological motion of the spine, decreases the incidence of adjacent segment degeneration and allows early return to function. It must be pointed out, however, that while the initial results of these operations appear promising it is still ‘early days’ as far as this treatment is concerned and caution is urged with regard to undergoing this procedure. It must be understood that the procedure is not suitable for everybody suffering from spondylotic degeneration in the neck. It is contraindicated where the degeneration is advanced and where the movements of the intervertebral level is already compromised, or where the individual undertakes activities which may put a large strain on the neck. The National Institute for Clinical Excellence (NICE) is still considering this procedure and has not yet put out any recommendations regarding it.

Complications of Spinal Surgery

You must note that surgical procedures on the spine are not without their problems. While every effort is made to undertake the procedure carefully and safely, things sometimes (inadvertently) do go wrong. Although the risks are very low some of the following mishaps, rarely, can occur during the operation, some of which may require further surgery:

• Continuing pain and/or numbness and/or weakness  and/or ‘pins and needles in arms and/or legs.
• Damage to the nerve roots or spinal cord, with postoperative neurological defects, including bowel and bladder dysfunction.
• Neurological deficits in the limbs with permanent nerve damage and paralysis.
• Difficulty with swallowing
• Difficulty with speaking
• Dural tears with meningocoele and/or cerebrospinal fluid fistulas.
• Excessive blood loss.
• Injury to blood vessels.
• Injury to oesophagus
• Infection of the vertebrae, discs or meninges.
• Epidural scarring.
• Intermittent vertigo.