The NORDSTEN Studies/ The Spinal Stenosis Study

Study Overview
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Brief Summary
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Lumbar Spinal Stenosis (LSS) is a clinical entity were narrowing of the spinal canal gives a compression of the the neural and vascular structures in the spinal canal. This often gives neurogenic claudication and sometimes severe Low Back Pain (LBP). Surgery for LSS is today the most often performed procedure in the adult lumbar spine. Beneficial effect of surgical treatment is well documented by several clinical trials, and a Cochrane review article from 2005 concludes that surgical treatment is superior to non-surgical treatment. The surgical solution is to decompress the stenotic part of the lumbar spine. There is no consensus in the literature of which surgical method that gives best long term clinical results. The investigators are therefore planning a Randomized Controlled Trial, where they will compare clinical and radiological results of three different surgical methods for LSS. The main outcome of this study is to answer which surgical method that gives the best long term clinical results. And, secondary outcome is to find out how much increase of the Dural Sac Cross Sectional Area is needed to give a long time relief of the patients' symptoms.

Official Title
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Comparison of Different Surgical Treatments for Lumbar Spinal Stenosis. A Randomized Controlled Trial Comparing the Clinical and Radiological Results Using Spinous Process Osteotomy, Bilateral Laminotomy and Unilateral Laminotomy With Crossover

Conditions
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Lumbar Spinal Stenosis

Intervention / Treatment
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* Procedure: Bilateral laminotomy (BL)
* Procedure: Unilateral laminotomy with crossover (UL)
* Procedure: Spinous Process Osteotomy (SPO)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: have clinical symptoms of spinal stenosis as neurogenic claudication or radiating pain into the bilaterally to the lower limbs, not responding to at least 3 months of conservative treatment. Radiological findings corresponding to the clinical symptoms of LSS. Central -stenosis, or lateral recess-stenosis. be able to give informed consent and to answer the questionnaires. over 18 years of age-have -not responding to at least 3 months of non-surgical treatment. be able to understand Norwegian language, spoken and in writing Exclusion Criteria: have a degenerative lumbar spondylolisthesis, with a slip ≥ 3 mm verified on standing plain x-rays in lateral view. are not willing to give written consent. have former surgery in the level of stenosis. fracture, or former fusion of the thoracolumbal region. cauda equina syndrome (bowel or bladder dysfunction) or fixed complete motor deficit. are ASA- classified 4 or 5. are older than 80 years have a lumbosacral scoliosis more than 20 degrees verified on AP-view have distinct symptoms in one or both of their legs due to other diseases, e.g. polyneuropaty, vascular claudication or osteoarthtris. LSS in 4 or more levels. not able to comply fully with the protocol, including treatment, follow-up or study procedures (psychosocially, mentally and physical). the patient is participating in another clinical trial that may interfere with this trial

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

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


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Bilateral laminotomy (BL)<br>The multifidus muscles is detached from the spinous process bilaterally.The decompression of the spinal canal is performed by first doing a flavectomy. Thereby performing a laminotomy (about 1/3) of the the lower part of the superior lamina, and a laminotomy of the upper part (about 1/4) of the inferior lamina. This is performed bilaterally. | Procedure: Bilateral laminotomy (BL)<br> <br> * Other names: Multiple laminotomies.;|
| Active Comparator: Unilateral laminotomy with crossover (UL)<br>The multifidus muscles is detached from the spinous process unilaterally. The laminotomy is first performed ipsilaterally. The decompression of the spinal canal is performed by first doing a flavectomy. Then, performing a laminotomy (about 1/3) of the the lower part of the superior lamina, and a laminotomy of the upper part (about 1/4) of the inferior lamina. Dura is then retracted, and the decompression is performed contralaterally. | Procedure: Unilateral laminotomy with crossover (UL)<br> <br> * Other names: microdecompression.;|
| Active Comparator: Spinous process osteotomy (SPO)<br>The multifidus muscles is detached from the spinous process unilaterally. An osteotomy of the superior spinous process is performed at the basis, in the actual level. The spinous process with intact interspinal and supraspinal ligaments is then retracted to the contralateral side. The decompression is first performed in the midline. Then one goes laterally on both sides too perform the decompression. About 1/3 of the lower part of the superior lamina is removed, and about 1/4 of the upper part of the inferior lamina is removed. | Procedure: Spinous Process Osteotomy (SPO)<br> <br> * Other names: Micro Spinous Process Osteotomy;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Oswestry Disability Index | The investigators will monitor the ODI-index before and after surgery, and calculate the change of ODI after surgery compared to baseline. The primary outcome is a measurement of the change of ODI (version 2.0) from baseline in the three different surgical groups. This will be done by calculating the mean ODI improvement in each group. The investigators will also compare the proportion of success patients between the SPO group, the BL group and the UL group, 24 months after the operation. The investigators will dichotomize the patients, in a succesful outcome group and in a non- succesful outcome group. The threshold value for being categorized as a succesful outcome will be computed in a planned study based on data from The Norwegian Registry for Spine Surgery (NORSpine). The investigators also plan to asses short time results after 2 years, intermediate results after 5 years, and long time results after 10 years. | 2, 5 and 10 years after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Zurich claudification Scale, Numeric Rating Scale for leg pain, Numeric Rating Scale for back pain, EQ-5D, and self evaluated effect of surgery. | All of the above mentioned questionaires are validated and reliable questionaires to asses the effect of surgical treatment. The effect of the surgical treatment is calculated by the improvement of the different scores, and thereby is an objective way to asses the effect of the surgical treatment. The investigators plan to asses short time results after 2 years, intermediate results after 5 years, and long time results after 10 years. | 2, 5 and 10 years after surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Lumbar Spinal stenosis, Surgical treatment of LSS.