Prosthetic intervertebral disc replacement in the cervical spine

# Guidance
This guidance replaces the previous guidance on Prosthetic intervertebral disc replacement in the cervical spine (Interventional Procedures Guidance no. 143, 2005).
Current evidence on the efficacy of prosthetic intervertebral disc replacement in the cervical spine shows that this procedure is as least as efficacious as fusion in the short term and may result in a reduced need for revision surgery in the long term. The evidence raises no particular safety issues that are not already known in relation to fusion procedures. Therefore this procedure may be used provided that normal arrangements are in place for clinical governance, consent and audit.
This procedure should only be carried out in specialist units where surgery of the cervical spine is undertaken regularly.
NICE encourages further research into prosthetic intervertebral disc replacement in the cervical spine. Research outcomes should include long-term data on preservation of mobility, occurrence of adjacent segment disease and the avoidance of revision surgery.# The procedure

# Indications and current treatments
Degenerative cervical disc disease may present with symptoms of pain and stiffness in the neck, and pain, paraesthesia, numbness or weakness of the limbs.
Conservative treatment options include rest, analgesic medication, physical therapy and local injections. In patients who are refractory to conservative treatment or at risk of permanent neurological damage, decompression of nerve roots or the spinal cord by cervical discectomy may be offered, with or without vertebral body fusion using a bone graft or cage.

# Outline of the procedure
Prosthetic intervertebral discs are implants that can be inserted between the vertebrae as an alternative to fusion using bone grafts or cages. They are designed with the aim of preserving the mobility of the diseased intravertebral segment, and therefore reducing the risk of adjacent segment degeneration in the long term.
With the patient under general anaesthesia and in the supine position, the anterior cervical spine is exposed. After standard decompression of the neural elements, and partial or full removal of the damaged disc, the artificial disc prosthesis is placed into the intervertebral space. More than one disc can be replaced during the same procedure.
Various devices can be used for this procedure.
Sections 2.3 and 2.4 describe efficacy and safety outcomes from the published literature that the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the overview.

# Efficacy
A randomised controlled trial (RCT) of 541 patients reported that improvement from baseline in mean Neck Disability Index (NDI) score (10-item questionnaire scored out of 100; higher scores indicate greater disability) was significantly greater in patients treated with prosthetic cervical disc insertion (55.7 to 20.7 points) compared with fusion (56.4 to 26.8 points) at 3-month follow-up (p = 0.004), but this difference was not significant at 6-, 12- or 24-month follow-up.
An RCT of 463 patients reported a greater improvement from baseline in mean NDI score in patients treated with a prosthetic cervical disc (51.4 to 16.2 points) than in those treated by fusion (50.2 to 19.2 points) at 24-month follow-up (p = 0.025).
A case series of 54 patients, who received 77 prosthetic cervical discs between them, reported no heterotopic ossification in 34% (26/77) of implants, bridging ossification but with preservation of prosthesis movement in 10% (8/77), and complete fusion of the level in 9% (7/77) at 1-year follow-up.
RCTs of 541, 463 and 209 patients all reported that baseline quality of life measurements (using Short Form-36 physical and mental health components) improved significantly at 24-month follow-up in patients treated by either prosthetic cervical disc insertion or fusion, but that differences between groups were not statistically significant (absolute figures not stated).
The Specialist Advisers listed key efficacy outcomes as NDI score, arm and neck pain score measured by visual analogue scale, Short Form-36 score, technical success and revision rate, range of movement and reduction in rate of adjacent level disease after 5 to 10 years.

# Safety
Revision surgery was required in 0% (0/276) of patients treated with a prosthetic cervical disc and 2% (5/265) of patients treated by fusion at 2-year follow-up in the RCT of 541 patients (p = 0.028). The rate of supplemental fixation in the neck (not otherwise defined) requiring additional surgery was significantly lower among patients treated with a prosthetic disc (0% ) than those treated by fusion (3% ) (p = 0.003).
Cerebrospinal fluid leak during decompression surgery occurred in 2% (1/43) of patients treated with prosthetic cervical discs at 2 levels in a non-randomised controlled trial of 146 patients (subsequent management and sequelae not described).
A case report described fracture of the posterior central parts of the caudal C6 and the cranial C7 vertebrae during the procedure. Bleeding occurred during the procedure, caused by bony fragments avulsed from the fracture compressing the posterior longitudinal ligament and the thecal sac (bleeding controlled and disc inserted without further complication).
The Specialist Advisers listed possible adverse events as implant migration or loosening, paraplegia, disc extrusion following trauma, segmental kyphosis and inadequate decompression. They considered theoretical adverse events to include infection, fusion of prosthesis, need for explantation surgery, disc debris causing inflammatory response, wear to the disc and osteolysis.# Further information
For related NICE guidance see our website.

# Information for patients
NICE has produced information on this procedure for patients and carers ('Understanding NICE guidance'). It explains the nature of the procedure and the guidance issued by NICE, and has been written with patient consent in mind.# About this guidance
NICE interventional procedure guidance makes recommendations on the safety and efficacy of the procedure. It does not cover whether or not the NHS should fund a procedure. Funding decisions are taken by local NHS bodies after considering the clinical effectiveness of the procedure and whether it represents value for money for the NHS. It is for healthcare professionals and people using the NHS in England, Wales, Scotland and Northern Ireland, and is endorsed by Healthcare Improvement Scotland for implementation by NHSScotland.
This guidance was developed using the NICE interventional procedure guidance process.
It updates and replaces NICE interventional procedure guidance 143.
We have produced a summary of this guidance for patients and carers. Information about the evidence it is based on is also available.
If you wish to be updated to any developments with this procedure, you can express an interest via our website.
Changes since publication
January 2012: minor maintenance.
Your responsibility
This guidance represents the views of NICE and was arrived at after careful consideration of the available evidence. Healthcare professionals are expected to take it fully into account when exercising their clinical judgement. This guidance does not, however, override the individual responsibility of healthcare professionals to make appropriate decisions in the circumstances of the individual patient, in consultation with the patient and/or guardian or carer.
Implementation of this guidance is the responsibility of local commissioners and/or providers. Commissioners and providers are reminded that it is their responsibility to implement the guidance, in their local context, in light of their duties to avoid unlawful discrimination and to have regard to promoting equality of opportunity. Nothing in this guidance should be interpreted in a way which would be inconsistent with compliance with those duties.
Copyright
 National Institute for Health and Clinical Excellence 2010. All rights reserved. NICE copyright material can be downloaded for private research and study, and may be reproduced for educational and not-for-profit purposes. No reproduction by or for commercial organisations, or for commercial purposes, is allowed without the written permission of NICE.
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