LLIF Plus Posterior Decompression for Severe Lumbar Spinal Stenosis

Study Overview
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Brief Summary
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Lateral lumbar interbody fusion (LLIF), as a minimally invasive technique, is an indirect decompression technique, and its decompression effect is not as thorough as traditional posterior decompression surgery. For certain patients with severe lumbar stenosis, additional posterior decompression is required. However, whether additional posterior decompression is necessary for these patients is unknown. Radiographic predictors of failed indirect decompression via LLIF is unknown. In current randomized, controlled trial , the investigators compare the clinical outcomes of patients with severe lumbar stenosis who received LLIF plus posterior decompression and those without posterior decompression.

Detailed Description
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The current randomized controlled trial consists of two groups. Patients included in the study are with Schizas's stenosis grades C. Patients in one group received transpsoas lateral lumbar interbody fusion. Patients in the other group received transpsoas lateral lumbar interbody fusion plus posterior decompression. Patients will be followed for one year. Clinical outcomes of the two groups will be compared. And radiographic predictors of failed indirect decompression via LLIF will be analyzed.

Official Title
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A Randomized, Controlled Trial of Lateral Lumbar Interbody Fusion Plus Posterior Decompression or Not for Severe Lumbar Spinal Stenosis

Conditions
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Lumbar Spine Degeneration, Lumbar Spinal Stenosis

Intervention / Treatment
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* Procedure: Lateral lumbar interbody fusion


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male and female patients who are 50 - 80 years of age. Patients who present with symptomatic Grade I or II degenerative spondylolisthesis at one or two contiguous lumbar levels between L1 and L5 and who are surgical candidates for interbody lumbar fusion surgery; symptoms should include radiculopathy and/or neurogenic claudication with or without back pain. Patients who have been unresponsive to at least 6 months of conservative treatments or who exhibit progressive neurological symptoms in the face of conservative treatment. Patients who understand the conditions of enrollment and are willing to sign an informed consent to participate in the study. Exclusion Criteria: Patients with lumbar pathologies requiring treatment at more than two levels. Patients who have had previous lumbar fusion surgery. Patients with congenital lumbar stenosis. Patients with radiographic confirmation of Grade IV facet joint disease or degeneration. Patients with noncontained or extruded herniated nucleus pulposus. Patients with active local or systemic infection. Patients with rheumatoid arthritis or other autoimmune disease. Patients who cannot undergo magnetic resonance imaging (MRI). Patients who are mentally incompetent. Patients with BMI over 30kg/m2 or less than 18 kg/m2.

Ages Eligible for Study
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Minimum Age: 50 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
Interventional Model Description: Patients included in this study are with degenerative lumbar stenosis and Schizas's stenosis grades C. Patients who suffered from significant lumbar scoliosis, grade 2 spondylolisthesis, lumbar fracture and prior lumbar surgery are excluded from this study.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Lateral lumbar interbody fusion<br>Patients in this group received lateral lumbar interbody fusion alone. Patients who suffered residual neurologic symptoms postoperatively will received conservative treatment for at least 3 months.Patients were considered to have unsuccessful indirect decompression if they had less than 20% improvement according to the Oswestry Disability Index (ODI) by 3 months postoperatively. | Procedure: Lateral lumbar interbody fusion<br>* LLIF is an indirect decompression technique, and does not directly remove the disc or osteophyte protruding into the spinal canal. Its decompression effect is not as thorough as traditional posterior decompression surgery. Usually, posterior decompression is required for patients who have unsuccessful indirect decompression.<br>|
| Experimental: Lateral lumbar interbody fusion plus posterior decompression<br>Patients in this group received lateral lumbar interbody fusion plus posterior decompression. | Procedure: Lateral lumbar interbody fusion<br>* LLIF is an indirect decompression technique, and does not directly remove the disc or osteophyte protruding into the spinal canal. Its decompression effect is not as thorough as traditional posterior decompression surgery. Usually, posterior decompression is required for patients who have unsuccessful indirect decompression.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Oswestry Disability Index (ODI) | The ODI is an extremely important tool that researchers and disability evaluators use to measure a patient's permanent functional disability | Preoperative, 3-month, 12-month,24-month after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Visual Analogue Scale (VAS) | The VAS is a self-report measure of the intensity of pain (score range 0 - 10 ). A higher score indicates greater pain intensity. | Preoperative, 3-month, 12-month,24-month after surgery | 
| Zurich Claudication Questionnaire(ZCQ) | The ZCQ is a disease-specific self-report outcome instrument commonly used in trials to measure treatment outcomes in patients with lumbar spinal stenosis.The result is expressed as a percentage of the maximum possible score (22.22% - 100%). The score increases with worsening disability.The The ZCQ consists of three subscales: symptom severity scale, physical function scale and patient's satisfaction with treatment scale. | Preoperative, 3-month, 12-month,24-month after surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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indirect decompression, lateral interbody fusion, lumbar, direct decompression