Interventional procedure consultation document

Non-rigid stabilisation techniques for the treatment of low back pain

Chronic low back pain is most often the result of normal wear and tear (degenerative change), which affects most people during their middle years, causing loss of height of the spinal discs and arthritis of the spinal joints. Non-rigid stabilisation (otherwise known as flexible or dynamic stabilisation) of the lumbar spine is intended to improve chronic low back pain by reducing painful movement without rigidly fusing the spine.

The National Institute for Health and Clinical Excellence (NICE) is examining non-rigid stabilisation techniques for the treatment of low back pain and will publish guidance on their 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 procedures. The Advisory Committee has made provisional recommendations about non-rigid stabilisation techniques for the treatment of low back pain.

This document summarises the procedures 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 these procedures. 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• The Advisory Committee will then prepare draft guidance which will be the basis for NICE’s guidance on the use of the procedures in the NHS in England, Wales, Scotland and Northern Ireland.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 July

Target date for publication of guidance: November 2010

1   Provisional recommendations

1.1  Current evidence on the efficacy of non-rigid stabilisation techniques for the treatment of low back pain shows that these procedures are efficacious for a proportion of patients with intractable back pain. There are no major safety concerns. Therefore these procedures may be used provided that normal arrangements are in place for clinical governance, consent and audit.

1.2  Patient selection should be carried out by specialist spinal surgeons who are able to offer patients a range of surgical treatment options.

2   The procedure

2.1  Indications and current treatments

2.1.1  Chronic low back pain commonly results from degenerative change of the intervertebral discs and/or spinal facet joints.

2.1.2  Conservative treatments include advice and education, posture and exercise training, manual therapies, analgesics, non-steroidal anti-inflammatory medication and acupuncture. For patients with severe, life-limiting chronic low back pain that is refractory to conservative interventions, surgery may be appropriate, such as spinal fusion procedures or insertion of prosthetic intervertebral discs.  

2.2   Outline of the procedure

2.2.1  Non-rigid (otherwise known as flexible or dynamic) stabilisation of the lumbar spine involves insertion of implants that aim to support and partially restrict the movement of spinal segments, and to minimise abnormal loading in adjacent segments.

2.2.2  With the patient under general or epidural anaesthesia, the intervertebral space is accessed using a posterior approach via a midline incision, and implants are inserted and fixed on the vertebrae.

2.2.3  More than one segment may be operated on at the same time. The procedure may be done in combination with laminectomy and/or discectomy where appropriate.

2.2.4  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 these procedures. For more detailed information on the evidence, see the overview, available at www.nice.org.uk/IP306aoverview

2.3  Efficacy

2.3.1  A non-randomised comparative study of 45 patients (18 non-rigid stabilisation vs 27 fusion) reported that additional surgery was required for adjacent-level disc lesion, disc herniation or spinal stenosis in 1 patient in the non-rigid stabilisation group and 5 patients in the fusion group at mean follow-ups of 71 months and 75 months respectively (significance not stated).

2.3.2  A case series of 101 patients reported that 15% (15/101) of patients required further procedures by 1–year follow-up, of which 10 out of a total of 18 were revision surgery (including decompression, extension of segmental fixation or removal of a synovial facet cyst) for increased back pain, radiculopathy or increased stability.

2.3.3  A case series of 83 patients reported that 13% (11/83) of patients required further spinal surgery at mean 38.1-month follow-up, including implant removal in 8 patients (3 for unresolved pain) of whom 6 required fusion of the index segment; extension of non-rigid stabilisation to adjacent segments in 2 patients; and decompression surgery of the index or adjacent segments, which was carried out twice in 1 patient.

2.3.4  The non-randomised comparative study of 45 patients (18 non-rigid stabilisation vs 27 fusion) reported adjacent-segment disc deterioration at the L2–L3 level confirmed by X-ray in 7% and 36% of patients at mean follow-ups of 71 months and 75 months respectively (p < 0.05).

2.3.5  A non-randomised comparative study of 103 patients (46 non-rigid stabilisation vs 57 rigid stabilisation) reported a reduction in back pain (measured on a visual analogue scale [VAS] from 0–10; higher score indicates greater pain) from 7.3 pre-operatively to 1.4 for the non-rigid stabilisation group, compared with a reduction from 7.4 to 2.1 for the rigid stabilisation group at mean follow-ups of 9.3 and 10.6 months respectively (p = not significant).

2.3.6  The case series of 101 patients reported a significant decrease in mean leg pain (measured on a VAS from 0–100) from 80.3 at baseline to 25.6 at 1-year follow-up (p < 0.01).

2.3.7  The non-randomised comparative study of 103 patients (46 non-rigid stabilisation vs 57 rigid stabilisation) reported improvement in disability (measured on the Oswestry Disability Index ([ODI] scale 0–100%; higher scores indicate greater disability) following both procedures. The mean ODI score in the non-rigid stabilisation group improved from 35.2 pre-operatively to 12.1 at a mean follow-up of 9.3 months; the rigid stabilisation group ODI score improved from 37.8 pre-operatively to 13.6 at mean follow-up of 10.6 months (significance not stated).

2.3.8  The case series of 101 patients reported a significant increase in Short Form-12 mental component scores (on a scale from 0–100; higher score indicates better quality of life) from 41.6 to 49.4 and physical component scores from 27.3 to 40.3 at 1-year follow-up (p < 0.01), and that 79% (63/80) of patients were satisfied at 1-year follow-up.

2.3.9  The Specialist Advisers listed key efficacy outcomes as relief of pain, ODI, return to work, patient satisfaction and quality of life, reduction in adjacent segment disease and revision rates.

2.4  Safety

2.4.1  Dural tears were reported in 12% (12/101) of patients in a case series. Eleven of the tears were repaired intraoperatively, of which 1 continued to leak and required surgical closure. One tear was discovered postoperatively.

2.4.2  The non-randomised comparative study of 103 patients (46 non-rigid stabilisation vs 57 rigid stabilisation) reported screw fracture in 1 patient in the non-rigid stabilisation group at 3 months and 1 patient with a loosened screw housing cap at day 7, which was retightened (unclear which treatment group).

2.4.3  The case series of 101 patients reported 1 patient in whom the vertebral pedicle fractured during screw insertion. The pedicle screw was not placed and a hemilaminectomy was done.

2.4.4  The case series of 83 patients reported 2 patients with screw misplacement (1 patient required revisional surgery) and 7 cases of screw loosening (confirmed by X-ray).

2.4.5  The Specialist Advisers considered theoretical adverse events to include paralysis, vessel or visceral injury, adjacent level disc degeneration, increase in lordosis, nerve root entrapment, screw malpositioning leading to sciatica or nerve damage, weakness and numbness; screw breakage leading to construct failure and infection.

3  Further information

3.1  This guidance is a review of ‘Non-rigid stabilisation procedures for the treatment of low back pain’ NICE interventional procedures guidance 183 (2006).

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

Bruce Campbell

Chairman, Interventional Procedures Advisory Committee
July 2010

_{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.}