Interbody vs Instrumented Posterolateral Fusion Following Decompression for Lumbar Spinal Stenosis With Degenerative Spondylolisthesis

Study Overview
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Brief Summary
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Degenerative spondylolisthesis describes the slip of one spinal segment relative to the adjacent segment. It is usually associated with spinal stenosis (which limits one's ability to walk and stand) and is the most common indication for surgery in adults over age 65 years. A variety of surgical techniques are available; the most common are the Posterolateral Instrumented Fusion (PLF), and Interbody Fusion (IF) including Posterolateral Interbody Fusion (PLIF), and Transforaminal Interbody fusion (TLIF). IF uses a cage that is placed within the cleaned out disc space between the vertebral bodies being fused. Although this approach achieves a good fusion rate and deformity correction it is associated with a higher surgical cost and potential intra-operative complication rate. What is more, no consensus exists as to whether IF provides better patient rated functional outcome and quality of life. If the advantages of IF do not translate into superior patient rated outcomes, then the risk-benefit ratio would be tipped in favor of PLF. The purpose of this study is to determine if IF is equivalent to PLF for the treatment of degenerative spondylolisthesis. The investigators will conduct a prospective randomized control trial comparing these two procedures. Our primary outcome measure will be the Oswestry Disability Index, which evaluates spinal pain and function.

Official Title
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Interbody Fusion and Decompression Versus Instrumented Posterolateral Fusion and Decompression for Lumbar Spinal Stenosis With Degenerative Spondylolisthesis

Conditions
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Degenerative Spondylolisthesis, Spinal Stenosis

Intervention / Treatment
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* Procedure: Interbody Fusion
* Procedure: Posterolateral Fusion


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients aged 50 years or older Grade I or II (less than 50% slip of the cephalad vertebra compared to the caudal vertebra) degenerative spondylolisthesis at one or two contiguous levels between L1 and L5. Lumbar spinal stenosis at the same levels of the degenerative spondylolisthesis producing radiculopathy or neurogenic claudication unresponsive to a minimum of 3 months of non surgical treatment Patients who are medically suitable for surgical management Patients who have consented for surgical treatment Patients able to provide informed consent for the study and complete the questionnaires Exclusion Criteria: Lytic spondylolisthesis Non degenerative stenosis (example: tumor, trauma, epidural lipomatosis) Severe vertical foraminal stenosis necessitating interbody insertion to re-establish foraminal height Segmental kyphosis at the level of the spondylolisthesis Segmental scoliosis >10 degrees at the level of the spondylolisthesis Rheumatoid arthritis Active infection On long term disability or workers compensation claim Drug or alcohol misuse Lack of permanent home residence Previous surgery at the proposed surgical level Previous fusion in the lumbar spine Contraindication to surgery: medical co morbidities Unable to complete questionnaire (e.g. Dementia) Unable to give voluntary consent

Ages Eligible for Study
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Minimum Age: 50 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: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Interbody Fusion<br> | Procedure: Interbody Fusion<br>* The interbody fusion (IF) procedure requires exposure and removal of the disc, curetting the end plates, inserting a cage filled with bone graft, as well as stabilization with rods and screws.<br>* Other names: Transforaminal Interbody fusion (TLIF);|
| Active Comparator: Posterolateral Fusion<br> | Procedure: Posterolateral Fusion<br>* In posterolateral fusion stabilization is achieved using pedicle screws joined by rods. The graft used to facilitate fusion is placed between decorticated transverse processes and can be an autograft of iliac bone or local bone, allograft, or a synthetic expander.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Oswestry Disability Index | The Oswestry Disability Index is an effective method of measuring disability in patients with back and leg pain and is well suited to patients who have had persistent severe disability. It is a commonly utilized, validated, and highly reproducible. The questionnaire can be completed in less than 5 minutes and a large amount of normative data exists. | 1 year post surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Oswestry Disability Index | The Oswestry Disability Index is an effective method of measuring disability in patients with back and leg pain and is well suited to patients who have had persistent severe disability. It is a commonly utilized, validated, and highly reproducible. The questionnaire can be completed in less than 5 minutes and a large amount of normative data exists. | Enrollment, and at 6 weeks, 3 months, 6 months, 2 years, 5 years and post surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Spinal Stenosis, Posterolateral Fusion, Interbody Fusion, Lumbar, Degenerative Spondylolisthesis