DIAM™ Spinal Stabilization System vs. Decompression, Formerly vs. Posterolateral Fusion

Study Overview
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Brief Summary
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The purpose of this clinical trial is to evaluate the safety and effectiveness of the DIAM Spinal Stabilization System as a method of treating patients with symptoms of degenerative lumbar spinal stenosis at a single level from L2 to L5.

Detailed Description
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This pivotal clinical trial is being conducted to evaluate the DIAM Spinal Stabilization System for the treatment of single-level degenerative lumbar spinal stenosis from L2 to L5. The implant under investigation in this clinical trial is the DIAM Spinal Stabilization System. And following a decompression procedure, the device will be implanted using a posterior surgical approach. Patients in the control group will receive a lumbar decompression.

Official Title
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A Prospective, Randomized, Controlled Pivotal Clinical Investigation of DIAM™ Spinal Stabilization System in Patients With Degenerative Lumbar Spinal Stenosis.

Conditions
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Degenerative Lumbar Spinal Stenosis

Intervention / Treatment
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* Procedure: Single-Level Posterior Decompression
* Device: DIAM Spinal Stabilization
* Device: DIAM Spinal Stabilization
* Device: Fusion


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Has a symptom complex consisting of back, buttock, or groin pain (excluding symptomatic coxarthrosis) with leg pain typical of intermittent neurogenic claudication, which is defined as leg(usually calf) discomfort, pain, numbness, paresthesias, weakness, or fatigue aggravated by standing or walking and is only relieved with resting in flexed lumbar spine position Leg pain score ≥ 8 and back pain score ≥ 6 based on the Preop Back/ Leg Pain CRF. Leg pain score must be ≥ back pain score Narrowing of the lumbar spinal canal and/or intervertebral foramen at L2-L3, L3-L4, L4-L5 as indicated by MRI, with other MRI findings typical of spinal stenosis, such as trefoil canal shape; hypertrophy, thickening, buckling, or infolding of the ligamentum flavum; hypertrophied facet joints or facet joint capsule; annular bulging; or lateral (subarticular) stenosis. Must sit for at least 30 min without severe pain Must walk at least 100 ft unassisted 35 yrs of age, inclusive Preoperative Oswestry score ≥ 40 Child-bearing potential, pt is not pregnant or nursing and agrees not to become pregnant during study period Treated non-operatively for a pd of at least 6 mos Willing and able to comply with study plan and able to understand and sign Pt ICF Exclusion Criteria: Disease state which requires destabilizing decompression Axial back pain with no pain in leg, buttock, or groin Baseline strength grade of 0 (total paralysis), 1 (palpable or visible contraction), or 2 (active movement, gravity,eliminated) in any lower extremity motor group as noted on Neuro Status CRF Segmental kyphosis >0° at indicated level Cauda equina syndrome Compression of nerve roots that causes neurogenic bowel, bladder dysfunction Prior surgical procedure at involved or adjacent levels Diagnosed with significant peripheral neuropathy Significant vascular disease causing vascular claudication Requires tx of spinal stenosis at more than 1 lumbar level Significant lumbar instability, defined as > 3mm translation on flexion/extension radiographs Has > 3mm fixed spondylolisthesis at affected level BMI ≥ 40 Sustained vertebral or hip fracture within last year Has the following (if Yes to any risk below, a lumbar spine DEXA Scan is required for eligibility) Previous diagnosis of osteoporosis, osteopenia, or osteomalacia Postmenopausal Non-Black female over age of 60 who weighs ≤ 140 lbs Postmenopausal female who has sustained a non traumatic hip, spine or wrist fracture Male over age of 60 who has sustained non-traumatic hip or spine fracture If level of DEXA T-score is -1.0 or lower pt is excluded from study Lumbar scoliosis with Cobb angle of > 15° Documented allergy to silicone, polyethylene, titanium or latex Overt or active bacterial infection, local, systemic, and/or potential for bacteremia Alcohol and/or drug abuser Received tx with investigational therapy (device and/or pharmaceutical) within 30 days prior to entering study or such tx is planned during the 24 mos following enrollment in study Suppressed immune system or has taken steroids at any dose daily for more than 1 mon within the last yr Presence of active malignancy or prior history of malignancy except for basal cell carcinoma of the skin History of any endocrine or metabolic disorder known to affect osteogenesis Chronic or acute renal and/or hepatic failure or prior history of renal and/or hepatic parenchymal disease History of autoimmune disease Disease which precludes accurate clinical evaluation of safety and effectiveness of txs in this study Congenital or iatrogenic posterior element insufficiency Moderate to advance spondylosis or pts who demonstrate advanced degenerative changes. Such advanced degenerative changes are characterized by 1 or combination of the following a Bridging osteophytes; b Reduction or absence of motion; c Collapse of the intervertebral disc space of > 50% of its normal ht Mentally incompetent Waddell Signs of Inorganic Behavior score of ≥ 3 Prisoner

Ages Eligible for Study
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Minimum Age: 35 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 |
| --- | --- |
| Experimental: DIAM Group1<br> | Device: DIAM Spinal Stabilization<br>* The DIAM Spinal Stabilization System is a spacer that is implanted between adjoining spinous processes using a posterior surgical approach.<br>|
| Active Comparator: Single-Level Posterior Decompression<br> | Procedure: Single-Level Posterior Decompression<br>* The single level posterior decompression is a posterior surgical procedure.<br>|
| Experimental: DIAM Group2<br> | Device: DIAM Spinal Stabilization<br>* The DIAM Spinal Stabilization System is a spacer that is implanted between adjoining spinous processes using a posterior surgical approach<br>|
| Active Comparator: Posterolateral Interbody Fusion<br> | Device: Fusion<br>* Posterolateral Interbody Fusion<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rate of Overall Success | Rate of overall success is reported as the percentage of partipants who met all of the following criteria: Pain/disability (ODI) success:(Success of ODI is defined as pain/disability improvement according to the definition: Pre-treatment Score - Post-treatment Score ≥ 15); Neurological success (Neurological success is defined as maintenance or improvement in sections of motor, sensory, reflex, and straight leg raise for the time period evaluated); No serious adverse event classified as surgical treatment associated; No additional surgical procedure classified as failure. | 24 months after operation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Oswestry Disability Index (ODI) Score | The self-administered Oswestry Disability Index (ODI) Questionnaire was used to assess patient pain and ability to function. The ODI scale ranges from 0-100. The best score is 0 (no disability) and worst is 100 (maximum disability). | 24 month after operation | 
| Success Rate of Oswestry Diability Index Scores | Success rate of Oswestry Diability Index Scores is reported as the percentage of participants who met: Pre-treatment Score - Post-treatment Score ≥ 15. | 24 month after operation | 
| Success Rate of Neurological Status | Success rate of neurological status is reported as the percentage of participants who met neurological success defined as maintenance or improvement in all sections (motor, sensory, reflex, and straight leg raising) for the time period evaluated. In order for a section to be considered a success, each element in the section must remain the same or improve from the time of the preoperative evaluation to the time period evaluated. | 24 month after operation | 
| Back Pain | Numerical rating scales are used to evaluate back pain intensity and frequency. Patients will rate their pain intensity on a scale from 0-10, with a score of 0 representing no pain and a score of 10 representing pain as bad as it could be. Similarly, patients will record their back pain frequency on a scale from 0-10, with a score of 0 being pain none of the time and a score of 10 being pain all of the time. A patient's total pain score will be the sum of pain intensity and frequency scores (0 min, 20 max). | 24 month after operation | 
| Back Pain Success Rate | Back pain success rate is reported as the percentage of participants whose back pain improvement met: (Pre Score - Post Score)/ Pre Score > 20%. | 24 month after operation | 
| Leg Pain | Numerical rating scales are used to evaluate leg intensity and frequency. Patients will rate their pain intensity on a scale from 0-10, with a score of 0 representing no pain and a score of 10 representing pain as bad as it could be. Similarly, patients will record their back pain frequency on a scale from 0-10, with a score of 0 being pain none of the time and a score of 10 being pain all of the time. A patient's total pain score will be the sum of pain intensity and frequency scores (0 min, 20 max). | 24 month after operation | 
| Leg Pain Success Rate | Leg pain success rate is reported as the percentage of participants whose leg pain improvement met: (Pre Score - Post Score)/ Pre Score > 20%. | 24 month after operation | 
| General Health Status (SF-36) | The Medical Outcomes Study 36-Item Short Form Health Survey (SF-36) was used to assess general health status. The SF-36 results are summarized into two components, a physical component summary (PCS) and a mental component summary (MCS). The score for PCS and MCS is between 0 and 100, with higher scores denoting better quality of life. | 24 month after operation | 
| Success Rate of SF-36 Health Survey | Success rate of SF-36 Health Survey include two components: the success rate of a physical component summary (PCS) and the success rate of a mental component summary (MCS). The success rates of SF-36 PCS and MCS for DIAM Device vs. Single-Level Posterior Decompression were defined as: (Post Score - Pre Score) / Pre Score>= 20%. The success rates of SF-36 PCS and MCS for DIAM vs. Posterolateral Interbody Fusion were defined as: Post Score - Pre Score >= 0. | 24 month after operation | 
| Operative Time |  | at the time of operation | 
| Blood Loss |  | At the time of operation | 
| Hospital Stay |  | At the time of discharge |