Spondylolisthesis Treated With an iO-Flex® System Enabled Decompression

Study Overview
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Brief Summary
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The purpose of this study is to evaluate the clinical performance of a decompression using the FDA cleared iO-Flex® System on-label in treating patients with spinal stenosis and stable grade I degenerative lumbar spondylolisthesis using a precision estimate assuming a 55% positive response rate.

Detailed Description
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This is a prospective, non-randomized, multi-center (up to 30 sites) controlled clinical study enrolling 100 subjects following a pre-specified protocol with no site enrolling more than 30 subjects. All eligible subjects providing written informed consent and meeting study eligibility criteria will receive a facet preserving decompression using the FDA cleared iO-Flex® system on label. Treatment success using the iO-Flex® System will be analyzed using a precision estimate assuming a 55% positive response rate. In addition to baseline characteristics and procedural parameters, subject outcomes will be assessed at 6 weeks, 6-, 12-, and 24 months. The study will have an extended follow-up phase with annual follow-up contact through 5 years to evaluate retreatment for the original indication at these late time points.

Official Title
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Spondylolisthesis Treated With an iO-Flex® System Enabled Decompression (STRiDE)

Conditions
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Radiculopathy, Spondylolisthesis, Lumbar Spinal Stenosis

Intervention / Treatment
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* Procedure: Decompression using the iO-Flex® system


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult (> 18 years of age) Leg/buttock pain, with or without back pain Grade 1 degenerative spondylolisthesis (≤25% slippage) NRS pain score for leg pain of 4/10 or greater ODI score of 30/100 or greater Failed non-operative medical management for a period of at least 6 months Confirmed clinical diagnosis of lumbar spinal stenosis Confirmation of central and/or lateral recess stenosis with or without foraminal stenosis, at one level or at two adjacent levels from L2-S1, with concordant symptoms. Subjects with central and/or lateral recess stenosis and spondylolisthesis at one level, may have symptomatic central, lateral recess or foraminal stenosis treated at one adjacent level. A below-the pedicle pass to decompress a third segment can be completed provided laminotomies are performed at no more than 2 levels. Subjects that, following an intraoperative decision, have a 3-level laminotomy and decompression will not be considered enrolled. Confirmation of spinal stenosis is shown on MRI or CT scan with evidence of nerve root impingement (displacement or compression) by either osseous or non-osseous elements. Ability to give voluntary, written informed consent to participate in this clinical investigation and ability to participate in follow up examinations and complete patient questionnaires Exclusion Criteria: Back pain only Diagnosis of moderate to severe peripheral neuropathy such as diabetic or idiopathic peripheral neuropathy, by EMG/NCS or a Neurologist. History of pathologic fractures of the vertebrae Primary disc pathology; planned or incidental discectomies will NOT be excluded as long as surgeon believes the disc pathology is not the primary reason for the surgical intervention. Subjects for whom removal of the midline structures is planned, likely or is the result of an intraoperative decision; every attempt should be made to spare the supraspinous, interspinous and facet capsular ligaments. Significant instability of the lumbar spine as defined by ≥ 4mm translational motion between standing lateral view flexion and extension radiographs Prior surgery of the lumbar spine Spondylolisthesis greater than grade 1 (on a scale of 1 to 4) Spondylolysis (pars fracture) at any level in the lumbar spine Degenerative lumbar scoliosis with a Cobb angle of ≥ 25° Vascular claudication in the lower extremities Cauda equina syndrome Evidence of active (systemic or local) infection at time of surgery Paget's disease at involved segment or metastasis to the vertebra, osteomalacia, or other metabolic bone disease Tumor in the spine or a malignant tumor except for basal cell carcinoma. Prisoner or transient Any significant psychological disturbance past or present, psychotic or neurotic that could impair the consent process or ability to complete subject self-report questionnaires Involved in pending litigation of the spine or worker's compensation related to the back Inability to communicate clearly in the English language Morbid obesity (BMI > 40) Pregnant, nursing, or planning on becoming pregnant. History of narcotic abuse Current involvement in another drug or device clinical trial Uncontrolled diabetes Irreversible coagulopathy or bleeding disorder (patients on anticoagulant therapy may participate. Investigators should follow routine practices for perioperative discontinuation and reinitiation of anticoagulants.) Plans to relocate in the next 2 years Subject unwilling to undergo a blood transfusion, if necessary

Ages Eligible for Study
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Minimum Age: 18 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: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Surgery<br>Decompression using the iO-Flex® system | Procedure: Decompression using the iO-Flex® system<br>* Decompression using the iO-Flex® system<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Oswestry Disability Index (ODI) | Responder analysis | 24 Months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Operative success | Achieving intended decompression using the iO-Flex® System. The number of neural foramen in which the iO-Flex® System was used for decompression compared to the number in which an attempt was made but not completed. | Operative (day 1) | 
| Oswestry Disability Index (ODI) | Responder analysis | 6, 12, 36, 48 and 60 months | 
| Oswestry Disability Index (ODI) | Comparison of ODI scores between baseline and each of the following follow-up visits: 6, 12, 24, 36, 48, and 60 month visits | 6, 12, 24, 36, 48 and 60 months | 
| Numerical Rating Scale (NRS) | Comparison of NRS scores for back and leg pain between baseline and each of the following follow-up visits: 6, 12, 24, 36, 48, and 60 month visits | 6, 12, 24, 36, 48 and 60 months | 
| Zurich Claudication Questionnaire (ZCQ) | Comparison of ZCQ scores between baseline and each of the following follow-up visits: 6, 12, 24, 36, 48, and 60 month visits | 6, 12, 24, 36, 48 and 60 months | 
| SF-36 Health Survey | Comparison of SF-36 scores between baseline and each of the following follow-up visits: 6, 12, 24, 36, 48, and 60 month visits | 6, 12, 24, 36, 48 and 60 months | 
| Treatment survival rate | To characterize longevity of the treatment effect of a decompression using the iO-Flex® System. | Ongoing out to 60 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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spondylolisthesis, lumbar spinal stenosis