Lumbar Disc Prosthesis Versus Multidisciplinary Rehabilitation; 8-year Follow-up

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

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

Conditions
-----------------
Chronic Low Back Pain

Intervention / Treatment
-----------------
* Procedure: Lumbar total disc replacement
* Behavioral: Multidisciplinary rehabilitation


Participation Criteria
=================
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.

Ages Eligible for Study
-----------------
Minimum Age: 25 Years
Maximum Age: 55 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Surgery<br>Replacement of the degenerative intervertebral lumbar disc with an artificial lumbar disc device (degeneration had to be restricted to the two lower levels (L4/L5 and/or L5/S1)) | Procedure: Lumbar total disc replacement<br>* The surgical intervention consisted of replacement of the degenerative intervertebral lumbar disc with a artificial lumbar disc device in one or two of the lover lumbal levels (L4/L5 or/and L5/S1). The ProDisc consists of three pieces, two metal endplates and a polyethylene core that is fixed to the inferior endplate when the device is implanted, and is implanted through a retroperitoneal (or transperitoneal) access.<br>* Other names: ProDisc II, Synthes Spine;|
| Active Comparator: Multidiciplinary rehabilitation<br> | Behavioral: Multidisciplinary rehabilitation<br>* The intervention is based on a treatment model described by Brox et al (Spine 2003;28:1913-1921) and is also described in details by Hellum et al (BMJ, May 2011). It consisted of a cognitive approach and supervised physical exercise and was delivered by a team of physiotherapists and specialists in physical medicine and rehabilitation. The rehabilitation programme lasted for about 60 hours over three to five weeks.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Oswestry Disability Index Oswestry Disability Index | Version 2.0 | Baseline, 6 weeks, 3 months, 6 months, 1, 2 and 8 years after inclusion to trial | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Low back pain | Measured by a VAS scale (0-100 mm) | Baseline, 6 weeks, 3 months, 6 months, 1, 2 and 8 years after inclusion to trial | 
| EQ-5D | general health status | Baseline, 6 weeks, 3 months, 6 months, 1, 2 and 8 years after inclusion to trial | 
| HSCL-25 | Hopkins Symptom Check List 25 for emotional distress | Baseline, 3 months, 6 months, 1, 2 and 8 years after inclusion to trial | 
| Work status |  | Baseline, 6 weeks, 3 months, 6 months, 1, 2 and 8 years after inclusion to trial | 
| Satisfaction with treatment outcome | 7 point Likert scale | Baseline, 6 weeks, 3 months, 6 months, 1, 2 and 8 years after inclusion to trial | 
| Satisfaction with care | 5 point Likert scale | Baseline, 6 weeks, 3 months, 6 months, 1 and 8 years after inclusion to trial | 
| Drug consumption | Daily, weekly, type | Baseline, 6 weeks, 3 months, 6 months, 1, 2 and 8 years after inclusion to trial | 
| Urinary incontinence | Stress incontinence, urge incontinence | Baseline, 3 months, 6 months, 1, 2 and 8 years after inclusion to trial | 
| Back surgeries and multidisciplinary rehabilitation | All surgeries and multidisciplinary rehabilitation due to low back pain will be registered | Baseline, 6 weeks, 3 months, 6 months, 1, 2 and 8 years after inclusion to trial | 
| Disc degeneration | Disc degeneration at adjacent level | Baseline, 2 and 8 years after inclusion to trial | 
| Facet joint degeneration | Facet joint degeneration at index level | Baseline, 2 and 8 years after inclusion to trial | 
| Cost-effectiveness | The EQ-5D questionnaire will be used to estimate patient utilities | Baseline, 6 weeks, 3 months, 6 months, 1, 2 and 8 years after inclusion to trial | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Chronic low back pain, Degenerated disc, Total disc replacement, Multidisciplinary rehabilitation, Long term results