Long-Term Outcomes for Lumbar Spinal Stenosis Patients Treated With X STOP®

Study Overview
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Brief Summary
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The Long-Term Outcomes Study (LTOS) is a multi-center longitudinal cohort study of all patients who received the X-STOP device in the Pivotal Trial, Continued Access Protocol (CAP), or Cross-over Study (COS). It is designed to supplement postmarket safety and effectiveness data to be gathered in a Condition of Approval (CoA) study of a population of patients with moderately impaired physical function who elect to undergo X-STOP surgery.

Detailed Description
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Evaluate the long term safety and effectiveness of the X-Stop interspinous process decompression system In the patients who received the X-Stop under the IDE. These patients consist of two cohorts to be evaluated: patients who had moderately impaired physical function prior to X-Stop implantation (as determined by a baseline score >2.0 in the physical function (PF) domain of the Zurich claudication questionnaire), and patients who had mildly impaired physical function prior to X-Stop surgery(as determined by a baseline score <=2.0 in the PF domain of the Zurich claudication questionnaire (ZCQ), through the fifth postoperative year. Clinical examination will be performed at each office visit to confirm the absence of neurological complications. X-ray films (AP/lateral views) taken during the fifth postoperative year will, be analyzed to confirm A) maintenance of distraction and B) the absence of radiological evidence of device-related complications. Secondary endpoints will include mean scores from the SF-36, and incidence rates of adverse events, device failures, and secondary surgeries.

Official Title
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Long-term Outcomes Among Patients With Lumbar Spinal Stenosis Treated With the X STOP® Interspinous Process Decompression System: Five-Year Follow-up of IDE Patient Cohorts

Conditions
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Lumbar Spinal Stenosis

Intervention / Treatment
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* Device: X STOP® Interspinous Process Decompression System


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: A patient will be admitted into the LTOS program if he/she meets all of the following inclusion criteria: Completed participation in the Pivotal Trial, CAP, or COS and has the X STOP implant(s) intact at the time of LTOS enrollment; OR is an active CAP/COS participant, has the X STOP implant(s) intact, and has not completed a 24-month follow-up visit in his/her CAP/COS study. Is willing and able to provide Informed Consent Is willing and able to return to the clinic for a clinical evaluation or complete study questionnaires without a clinic visit. Exclusion Criteria: A patient will not be admitted into the LTOS program if he/she meets any of the following exclusion criteria: Participated in the Pivotal Trial as part of the X STOP group, but the device has been removed. Participated in the CAP or COS programs, but the device has been removed.

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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Arms and Interventions

| Intervention/Treatment |
| --- |
|Device: X STOP® Interspinous Process Decompression System|The X STOP is a titanium implant that fits between the spinous processes of the lumbar spine. It is made from Ti-6AI-4V Eli titanium alloy (ISO 5832/3) and consists of two components: a spacer assembly and a wing assembly.|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Treatment Success Rates (At ≥ 5 Years) | Seven treatment success criteria were defined as follows: clinically significant improvement (at least 0.5 points) in Symptom Severity (SS) domain of Zurich Claudication Questionnaire (ZCQ), clinically significant improvement (at least 0.5 points) in Physical Function (PF) domain of ZCQ, Patient Satisfaction (PS) score of <2.5 points in ZCQ, no additional lumbar spinal stenosis surgery at the index level, maintenance of distraction, no device dislodgement, no device-related complications. All 7 criteria must be met to be considered a treatment success. | 3+ years following first 2 years post-X-STOP implant through IDE study | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Symptom Severity (SS) and Physical Functioning (PF) as Using Zurich Claudication Questionnaire (ZCQ) Domain Scores (At ≥ 5 Years) | ZCQ is a validated outcomes instrument specific to lumbar spinal stenosis, and captures data in 3 distinct domains: SS, PF, and post-treatment Patient Satisfaction (PS). SS domain is based on seven questions (overall pain, pain frequency, pain in the back, pain in the leg, numbness, weakness, and balanced disturbance). The first 6 questions are scored 1 to 5. Balance disturbance is scored in a 1-3-5 scale. The SS score is the mean of all answered items in the questionnaire ranging from 1to 5. If more than two items were missing, the SS score was considered as missing. PF score is the mean of five physical function questions ranging from 1 to 4. If more than one item were missing, the PF score was considered as missing. In each domain, a lower score represents a better outcome/condition. The change is calculated as the score at 5+ years after X-STOP implantation minus the baseline score. | Baseline and 3+ years following first 2 years post-X-STOP implant through IDE study | 
| Patient Satisfaction (PS) as Assessed by Zurich Claudication Questionnaire (ZCQ) Domain Scores (At ≥ 5 Years) | ZCQ is a validated outcomes instrument specific to lumbar spinal stenosis, and captures data in 3 distinct domains: SS, PF, and post-treatment Patient Satisfaction (PS). PS score is the mean of 6 questions scored from 1 to 4 if the number of responses exceeded four, a lower score represents a better outcome. Patients with mean scores <2.5 at 5 years postoperative evaluation were considered positive, which implied patient treatment satisfaction. | 3+ years following first 2 years post-X-STOP implant through IDE study | 
| Change in Quality of Life Using Short Form 36-Question (SF-36) Health Survey (At ≥ 5 Years) | Quality of life was assessed by the SF-36 health survey. It includes 8 subdomains (bodily pain, physical functioning, role-physical, general health and vitality, social functioning, role-emotional, and mental health) and 2 component summaries (physical component summary [PCS] and mental component summary [MCS]). Scores for each subdomain and component summary range from 0 worst to 100 best. The change from baseline to the 5 year postoperative visit for each of these domains is presented. | Baseline and 3+ years following first 2 years post-X-STOP implant through IDE study | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Lumbar Spinal Stenosis, X STOP