Prosthetic intervertebral disc replacement in the cervical spine - Second Consultation

NATIONAL INSTITUTE FOR HEALTH AND CLINICAL EXCELLENCE

Interventional procedure consultation document

Prosthetic intervertebral disc replacement in the cervical spine

Bulging of a disc (called herniation) in the neck occurs when one or more of the spinal discs between the bones in the neck bursts and pushes against the spinal cord or nerve roots that run through the backbone. This herniation can cause pain in the neck, or pain, weakness and numbness in the arms and legs.

This procedure involves replacing damaged discs in the neck with artificial ones designed to act like natural neck discs.

The National Institute for Health and Clinical Excellence (NICE) is examining prosthetic intervertebral disc replacement in the cervical spine and will publish guidance on its safety and efficacy to the NHS in England, Wales, Scotland and Northern Ireland. NICE’s Interventional Procedures Advisory Committee has considered the available evidence and the views of Specialist Advisers, who are consultants with knowledge of the procedure. The Advisory Committee has made provisional recommendations about prosthetic intervertebral disc replacement in the cervical spine

This document summarises the procedure and sets out the provisional recommendations made by the Advisory Committee. It has been prepared for public consultation. The Advisory Committee particularly welcomes:

  • comments on the provisional recommendations
  • the identification of factual inaccuracies
  • additional relevant evidence, with bibliographic references where possible.

Note that this document is not NICE’s formal guidance on this procedure. The recommendations are provisional and may change after consultation.

The process that NICE will follow after the consultation period ends is as follows.

  • The Advisory Committee will meet again to consider the original evidence and its provisional recommendations in the light of the comments received during consultation.
  • The Advisory Committee will then prepare draft guidance which will be the basis for NICE’s guidance on the use of the procedure in the NHS in England, Wales, Scotland and Northern Ireland.

For further details, see the Interventional Procedures Programme manual, which is available from the NICE website (www.nice.org.uk/ipprogrammemanual).

NICE is committed to promoting through its guidance race and disability equality and equality between men and women, and to eliminating all forms of discrimination. One of the ways we do this is by trying to involve as wide a range of people and interest groups as possible in the development of our guidance on interventional procedures. In particular, we aim to encourage people and organisations from groups in the population who might not normally comment on our guidance to do so. We also ask consultees to highlight any ways in which draft guidance fails to promote equality or tackle discrimination and give suggestions for how it might be improved. NICE reserves the right to summarise and edit comments received during consultations, or not to publish them at all, where in the reasonable opinion of NICE, the comments are voluminous, publication would be unlawful or publication would otherwise be inappropriate.

Closing date for comments: 27 January 2010

Target date for publication of guidance: April 2010

 

1       Provisional recommendations

1.1  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 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.

1.2  This procedure should only be carried out in specialist units where surgery of the cervical spine is undertaken regularly.

1.3  NICE encourages further research. Research outcomes should include long-term data on preservation of mobility and occurrence of adjacent segment disease and the avoidance of revision surgery.

2       The procedure

2.1    Indications and current treatments

2.1.1  Degenerative cervical disc disease may present with symptoms of pain and stiffness in the neck, and pain, paraesthesia, numbness or weakness of the limbs.

2.1.2  Conservative treatment options include rest, analgesic medication, physical therapy and local injections. In patients who are refractory to conservative treatment or who are 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 graft or cage. 

2.2    Outline of the procedure

2.2.1  Prosthetic intervertebral discs are mobile 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.

2.2.2  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.

2.2.3  A number of different devices are available 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, available at .www.nice.org.uk/IP265boverview.

 

2.3    Efficacy

2.3.1  A randomised controlled trial (RCT) of 541 patients reported that the mean Neck Disability Index (NDI) score (10-item questionnaire scored out of 100; higher scores indicate greater disability) improvement from baseline 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.

2.3.2  An RCT of 463 patients reported a greater improvement from baseline in mean NDI score in patients treated by a prosthetic cervical disc (51.4 to 16.2 points) than fusion (50.2 to 19.2 points) at 24-month follow-up (p = 0.025).

2.3.3  A case series of 54 patients receiving 77 prosthetic cervical discs between them reported no heterotopic ossification in 34% (26/77) of implants, bridging ossification but with preservation of movement of prosthesis in 10% (8/77), and complete fusion of the level in 9% (7/77) at 1-year follow-up.

2.3.4  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).

2.3.5  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.

2.4    Safety

2.4.1  Revision surgery was required in 0% (0/276) of patients treated with a prosthetic cervical disc and 2% (25/265) of patients treated by cervical 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% [0/276]) than fusion (3% [9/265]) (p = 0.003).

2.4.2  Cerebrospinal fluid (CSF) leak during decompression surgery occurred in 2% (1/43) of patients treated with prosthetic cervical discs at 2 levels in the non-randomised controlled trial of 146 patients (subsequent management and course not described).

2.4.3  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).

2.4.4  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.

3     Further information

3.1  This guidance requires that clinicians undertaking the procedure make special arrangements for audit. NICE has identified relevant audit criteria and is developing an audit tool (which is for use at local discretion), which will be available when the guidance is published.

3.2  For related NICE guidance see www.nice.org.uk.

Bruce Campbell
Chairman, Interventional Procedures Advisory Committee
December 2009

Personal data will not be posted on the NICE website. In accordance with the Data Protection Act names will be anonymised, other than in circumstances where explicit permission has been given.

 It is the responsibility of consultees to accurately cite academic work in order that they can be validated.

This page was last updated: 30 March 2010