Clinical trial NCT01704677: Lumbar Disc Prosthesis Versus Multidisciplinary Rehabilitation; 8-year Follow-up
Official title: Lumbar Disc Prosthesis Versus Multidisciplinary Rehabilitation in Chronic Back Pain and Localized Degenerative Disc. Long Term Follow-up of a Randomized Multicentre Trial
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Chronic Low Back Pain
Keywords: Chronic low back pain
Degenerated disc
Total disc replacement
Multidisciplinary rehabilitation
Long term results
Lead sponsor: Oslo University Hospital
Sponsor class: OTHER
Collaborators: name: St. Olavs Hospital
name: Haukeland University Hospital
name: Helse Stavanger HF
name: University Hospital of North Norway
First posted: 2012-10-11
Enrollment: 151
Sex: ALL
Minimum age (years): 25
Maximum age (years): 55
Standard ages: ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: During the past 25-30 years, surgery with total disc replacement (TDR) has become an option for a selection of patients with chronic low back pain (LBP) traditionally treated conservatively or operated on with spinal fusion. Randomized trials comparing TDR with fusion have found the clinical outcome of TDR at least equivalent to that of fusion, and the only study comparing TDR to non-surgical treatment (The Norwegian TDR study) concludes that TDR is significantly more effective than multidisciplinary rehabilitation (REHAB) after 2 years. However, the long-term effects of TDR in terms of clinical results, costs, reoperation- and revision rate, degenerative changes and prognostic factors have not been investigated in high quality prospective trials. This is very much required since TDR surgery is offered a great number of patients world wide, and is associated with high complexity and risk of serious complications and difficult revision. Hence, the overall aim of the present study is to evaluate the long term (eight years follow-up) effect of The Norwegian TDR study where TDR surgery were compared to modern multidisciplinary rehabilitation in patients with chronic low back pain and localized degenerative disc changes.

Detailed description: Two-year results of the Norwegian TDR study were published in BMJ in May 2011 (Hellum et al). The current protocol is 8-year follow-up of patients included in the Norwegian TDR study.

Hypothesis of the 8-year follow-up:

Main hypothesis (H0): There are no differences in change between TDR and REHAB for pain and disability measured by Oswestry Disability Index (main outcome), back pain, quality of life, psychological variables, work status, patients satisfaction, drug use, urinary incontinence, and back surgeries after 8 years.

Secondary Hypothesis:

1. There are no differences in incidence and degree of disc degeneration at adjacent level or facet joint degeneration at index level between groups (radiological analysis).
2. There is no association between baseline characteristics, pelvic anatomy / sagittal balance (defined by lumbar lordosis, pelvic tilt, pelvic incidence angle and sacral slope), and clinical outcome after TDR.
3. There is no difference in cost effectiveness between surgery and REHAB 8 years after inclusion to the study.

Statistical analysis:

The investigators will use the same analysis as for 2-years results: two-way ANOVA, mixed model, regression analysis. p\<0.05 will be considered statistically significant

Additional analysis (not conducted at 2 years):

1. cross-overs will receive last value before cross-over/fusion surgery
2. survival analysis
3. pelvic anatomy / sagittal balance (defined by lumbar lordosis, pelvic tilt, pelvic incidence angle and sacral slope) will be included in the predictor analysis
4. Both CT scans and MRI are taken for the evaluation of index level facet arthropathy

Eligibility criteria: Inclusion Criteria:

* aged 25-55 years
* had low back pain as the main symptom for at least 1 year
* structured physiotherapy or chiropractic treatment for at least 6 months without sufficient effect
* Oswestry Disability Index (ODI) of at least 30
* degenerative intervertebral disc changes in L4/L5 and/or L5/S1.Degeneration had to be restricted to the two lower levels. The following degenerative changes were evaluated: at least 40% reduction of disc height, Modic changes type I and/or II, high-intensity zone in the disc, and morphological changes classified as changes in signal intensity in the disc of grade 3 or 4. The disc was classified as degenerative if the first criteria alone or at least two changes were found on magnetic resonance imaging. The discs were independently classified by two observers (orthopaedic surgeon /radiologist). When in disagreement, the images were classified by a third observer and the outcome decided by simple majority.

Exclusion Criteria:

* Generalized chronic pain syndrome (widespread myofascial pain)
* Degeneration established in more than two levels. To be classified as a normal disc, the disc height must not be reduced more than 40% and all other criteria of degenerative disc disease aforementioned must be absent. The classification of a normal disc is performed by two independent observers. If disagreement, the pictures will be classified by a third observer and the outcome decided by simple majority.
* Symptoms of spinal stenosis
* Disc protrusion or recess stenosis with nerve root affection
* Spondylolysis
* Isthmic spondylolisthesis
* Arthritis
* Former fracture of L1 - S1
* Ongoing psychiatric or somatic disease that excludes either one or both treatment alternatives
* Does not understand Norwegian language, spoken or in writing
* Drug abuse
* Osteoporosis
* Congenital or acquired deformity

Patients were examined by an orthopaedic surgeon and a specialist in physical medicine and rehabilitation together, which had to agree on inclusion.

Primary outcomes:
measure: Oswestry Disability Index Oswestry Disability Index
timeFrame: Baseline, 6 weeks, 3 months, 6 months, 1, 2 and 8 years after inclusion to trial
Secondary outcomes:
measure: Low back pain
timeFrame: Baseline, 6 weeks, 3 months, 6 months, 1, 2 and 8 years after inclusion to trial
measure: EQ-5D
timeFrame: Baseline, 6 weeks, 3 months, 6 months, 1, 2 and 8 years after inclusion to trial
measure: HSCL-25
timeFrame: Baseline, 3 months, 6 months, 1, 2 and 8 years after inclusion to trial
measure: Work status
timeFrame: Baseline, 6 weeks, 3 months, 6 months, 1, 2 and 8 years after inclusion to trial
measure: Satisfaction with treatment outcome
timeFrame: Baseline, 6 weeks, 3 months, 6 months, 1, 2 and 8 years after inclusion to trial
measure: Satisfaction with care
timeFrame: Baseline, 6 weeks, 3 months, 6 months, 1 and 8 years after inclusion to trial
measure: Drug consumption
timeFrame: Baseline, 6 weeks, 3 months, 6 months, 1, 2 and 8 years after inclusion to trial
measure: Urinary incontinence
timeFrame: Baseline, 3 months, 6 months, 1, 2 and 8 years after inclusion to trial
measure: Back surgeries and multidisciplinary rehabilitation
timeFrame: Baseline, 6 weeks, 3 months, 6 months, 1, 2 and 8 years after inclusion to trial
measure: Disc degeneration
timeFrame: Baseline, 2 and 8 years after inclusion to trial
measure: Facet joint degeneration
timeFrame: Baseline, 2 and 8 years after inclusion to trial
measure: Cost-effectiveness
timeFrame: Baseline, 6 weeks, 3 months, 6 months, 1, 2 and 8 years after inclusion to trial
Other outcomes:
measure: Time to surgery
timeFrame: From baseline to 8 years after inclusion to the study
Locations:
city: Oslo
country: Norway
facility: Oslo University Hospital Ullevål
Study officials:
affiliation: Oslo University Hospital Ullevål
name: Kjersti Storheim, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Hellum C, Johnsen LG, Storheim K, Nygaard OP, Brox JI, Rossvoll I, Ro M, Sandvik L, Grundnes O; Norwegian Spine Study Group. Surgery with disc prosthesis versus rehabilitation in patients with low back pain and degenerative disc: two year follow-up of randomised study. BMJ. 2011 May 19;342:d2786. doi: 10.1136/bmj.d2786.
citation: Hellum C, Johnsen LG, Gjertsen O, Berg L, Neckelmann G, Grundnes O, Rossvoll I, Skouen JS, Brox JI, Storheim K; Norwegian Spine Study Group. Predictors of outcome after surgery with disc prosthesis and rehabilitation in patients with chronic low back pain and degenerative disc: 2-year follow-up. Eur Spine J. 2012 Apr;21(4):681-90. doi: 10.1007/s00586-011-2145-3. Epub 2012 Jan 13.
citation: Hellum C, Berg L, Gjertsen O, Johnsen LG, Neckelmann G, Storheim K, Keller A, Grundnes O, Espeland A; Norwegian Spine Study Group. Adjacent level degeneration and facet arthropathy after disc prosthesis surgery or rehabilitation in patients with chronic low back pain and degenerative disc: second report of a randomized study. Spine (Phila Pa 1976). 2012 Dec 1;37(25):2063-73. doi: 10.1097/BRS.0b013e318263cc46.
citation: Johnsen LG, Hellum C, Storheim K, Nygaard OP, Brox JI, Rossvoll I, Ro M, Andresen H, Lydersen S, Grundnes O, Pedersen M, Leivseth G, Olafsson G, Borgstrom F, Fritzell P; Norwegian Spine Study Group. Cost-effectiveness of total disc replacement versus multidisciplinary rehabilitation in patients with chronic low back pain: a Norwegian multicenter RCT. Spine (Phila Pa 1976). 2014 Jan 1;39(1):23-32. doi: 10.1097/BRS.0000000000000065.
citation: Berg L, Hellum C, Gjertsen O, Neckelmann G, Johnsen LG, Storheim K, Brox JI, Eide GE, Espeland A; Norwegian Spine Study Group. Do more MRI findings imply worse disability or more intense low back pain? A cross-sectional study of candidates for lumbar disc prosthesis. Skeletal Radiol. 2013 Nov;42(11):1593-602. doi: 10.1007/s00256-013-1700-x. Epub 2013 Aug 28.
citation: Johnsen LG, Hellum C, Nygaard OP, Storheim K, Brox JI, Rossvoll I, Leivseth G, Grotle M. Comparison of the SF6D, the EQ5D, and the oswestry disability index in patients with chronic low back pain and degenerative disc disease. BMC Musculoskelet Disord. 2013 Apr 26;14:148. doi: 10.1186/1471-2474-14-148.
citation: Johnsen LG, Brinckmann P, Hellum C, Rossvoll I, Leivseth G. Segmental mobility, disc height and patient-reported outcomes after surgery for degenerative disc disease: a prospective randomised trial comparing disc replacement and multidisciplinary rehabilitation. Bone Joint J. 2013 Jan;95-B(1):81-9. doi: 10.1302/0301-620X.95B1.29829.
citation: Berg L, Gjertsen O, Hellum C, Neckelmann G, Johnsen LG, Eide GE, Espeland A. Reliability of change in lumbar MRI findings over time in patients with and without disc prosthesis--comparing two different image evaluation methods. Skeletal Radiol. 2012 Dec;41(12):1547-57. doi: 10.1007/s00256-012-1394-5. Epub 2012 Mar 20.
citation: Garratt AM, Furunes H, Hellum C, Solberg T, Brox JI, Storheim K, Johnsen LG. Evaluation of the EQ-5D-3L and 5L versions in low back pain patients. Health Qual Life Outcomes. 2021 May 28;19(1):155. doi: 10.1186/s12955-021-01792-y.