One of the most common surgical strategies applied to the cervical spine has been removal of damaged symptomatic discs and fusion of the treated levels.
Fusion techniques are now less invasive, yet more certain and secure. There are many circumstances where a fusion operation is still required in the cervical spine, but an alternative strategy has emerged allowing a damaged disc to be removed in selected circumstances and replaced with an artificial (prosthetic) disc.
A number of artificial discs have been developed, and the design evolution has reached a point where artificial cervical discs have characteristics of function that are very similar to natural healthy discs – and often better than the damaged discs that they replace.
Disc replacement surgery can be considered when the spine is stable, and where removal of the disc and, if necessary, relief of nerve compression can be anticipated to relieve the presenting symptoms – typically arm pain caused by nerve root compression and neck pain.
The advantage of disc replacement over fusion is the preservation of mobility at the treated segment. This may result in a more natural feeling neck, and may reduce the incidence of accelerated degenerative changes of the discs above and below.
Currently, Medicare funding in Australia is only available for single level cervical or lumbar disc replacement.
Overseas surgical groups have performed and studied disc replacements at more than one level in the cervical spine, and their reported results are encouraging with respect to efficacy and safety.
Biomechanical testing of these devices suggests that they can be expected to last at least 30 years after implantation. It is important to note, however, that no devices have been implanted and followed for more than 12 years, and that laboratory based testing may not replicate the conditions within the human body.