Lumbar Spinal Stenosis
Conditions
Keywords
Lumbar Spinal Stenosis, X-STOP Spacer, Interspinous process decompression, Neurogenic Intermittent Claudication
Brief summary
This prospective, multicenter longitudinal five-year study of X-STOP PEEK usage in LSS patients is designed to supplement pre-market safety and effectiveness data with information on longer-term device performance in a population of patients with moderately impaired physical function at preoperative baseline (i.e., an indicated population) who elect to undergo X STOP PEEK surgery.
Detailed description
This prospective, multicenter longitudinal five-year study of X-STOP PEEK implant usage in LSS patients is designed to supplement pre-market safety and effectiveness data with information on longer-term device performance in a population of patients with moderately impaired physical function at preoperative baseline (i.e., an indicated population) who elect to undergo X-STOP PEEK surgery. This post-approval study will enroll 240 patients at up to 8 clinical sites where all participating spine surgeons have completed a company-sponsored physician training program. The clinical sites recruited to participate in this study comprise a geographically diverse mix of academic, referral, and/or community based sites. Safety and effectiveness data will be assessed at baseline and annually through five (5) years postoperatively. Office visits will be scheduled preoperatively, and at 6 weeks, 1, 2, 3, 4, and 5 years postoperatively. Clinical/neurological and radiographic examination will be performed during each office visit. A baseline patient history (including medication usage) will be taken, and concomitant medications will be recorded at each postoperative follow-up visit. In addition, patients will be asked to complete the following questionnaires prior to consultation with their physicians or their staff: Zurich Claudication Questionnaire (ZCQ), Oswestry Disability Index (ODI), Numeric Rating Scale (NRS), and SF-36 Health Survey. At the 2-, 3-, 4- and 5-year office visit, patients will also be asked two questions assessing the value of surgery and the overall improvement in the quality of life postoperatively. The primary study endpoint in this study is treatment success. Secondary endpoints will include scores from the SF-36, ODI, and NRS, as well as incidence rates of adverse events, device failures, and secondary surgeries.
Interventions
DEVICEX-STOP PEEK
Placement of X-STOP PEEK in up to two levels in the lumbar spine for patients diagnosed with moderately symptomatic lumbar spinal stenosis in accordance with current labeling instructions for use.
Sponsors
Medtronic Spine LLC
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
50 Years to No maximum
Healthy volunteers
No
Inclusion criteria
1. has a baseline score \>2.0 in the Physical Function (PF) domain of the Zurich Claudication Questionnaire 2. is 50 years old or older 3. has leg/buttock/groin pain with or without back pain NOTE: Leg/buttock/groin pain must be completely relieved when flexed such as when sitting in a chair. If back pain is also present, it must be partially relieved when flexed. 4. can sit for 50 minutes without pain 5. can walk 50 feet or more 6. has a confirmed diagnosis of neurogenic intermittent claudication secondary to lumbar spinal stenosis, with X-Ray, MRI and/or CT evidence of thickened ligamentum flavum, narrowed lateral recess and/or central canal narrowing 7. has completed at least six months of conservative care therapy which may include but is not limited to physical therapy, bracing, systemic or injected medications 8. has signed a patient informed consent document 9. is physically and mentally willing and able or has a caregiver who can comply with the postoperative and routinely scheduled clinical and radiographic evaluations 10. lives in the immediate area and has no plans to relocate to another geographic area before completion of the study or lives outside the immediate area and will comply with the scheduled postoperative visits with a prearranged and designated physician
Exclusion criteria
1. has a baseline score less than or equal to 2.0 in the Physical Function (PF) domain of the Zurich Claudication Questionnaire 2. cannot sit for 50 minutes 3. cannot walk more than 50 feet 4. has unremitting pain in any spinal position 5. has axial back pain only without leg/buttock/groin pain 6. has a fixed motor deficit 7. has cauda equina syndrome defined as neural compression causing neurogenic bowel (rectal incontinence) or bladder (bladder retention or incontinence) dysfunction 8. has severe symptomatic lumbar spinal stenosis at more than two levels 9. has significant instability of the lumbar spine, e.g., isthmic spondylolisthesis or degenerative spondylolisthesis greater than grade 1 (on a scale of 1 to 4) 10. has an ankylosed segment at the affected level(s); 11. has significant scoliosis (Cobb angle is greater than 25 degrees) 12. has an acute fracture of the spinous process or pars interarticularis 13. has sustained pathologic fractures of the vertebrae or multiple fractures of the vertebrae and /or hips 14. has severe osteoporosis of the spine or hip, defined as bone mineral density (BMD) in the spine or hip more than 2.5 SD below the mean of adult normals in the presence of one or more fragility fractures 15. has Paget's disease at the involved segment(s) or metastasis to the vertebrae 16. has had any surgery of the lumbar spine 17. has significant peripheral neuropathy demonstrated by nerve conduction velocity tests 18. has acute denervation secondary to radiculopathy, as shown by EMG 19. has significant peripheral vascular disease characterized by diminished dorsalis pedus or tibial pulses 20. has extreme obesity as defined by a Body Mass Index (BMI) greater than 40 kg/m2 21. has an active systemic infection or infection localized to the site of implantation 22. has an active systemic disease such as AIDS, HIV, hepatitis, etc. 23. has a medical condition that may interfere with postoperative management and follow-up, or may result in patient death prior to study completion (e.g., Alzheimer's disease, unstable cardiac disease, active malignancy) 24. has a recent history of narcotic abuse (i.e., within last 3 years) 25. has a known allergy to titanium,titanium alloy, or polyetheretherketone 26. is immunologically suppressed, or has received or is receiving steroids at any dose daily for more than one month within the last 12 months 27. is currently involved in a study of another investigational product that may affect the outcome of this study 28. is pregnant or planning to become pregnant during the study period 29. cannot undergo MRI or tolerate closed MRI scanning.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Treatment Success Rate at 24 Months | 24 months | Treatment success rate is reported as the percentage of participants who met all of the following criteria: 1. Clinically significant improvement (by at least 0.5 points) in the Symptom Severity (SS) domain of the Zurich Claudication Questionnaire (ZCQ) compared to preoperative baseline 2. Clinically significant improvement (by at least 0.5 points) in the Physical Function (PF) domain of the ZCQ compared to pre-operative baseline 3. Patient satisfaction with treatment defined as a Patient Satisfaction (PS) score \< 2.5 4. No additional surgery for lumbar stenosis performed 5. Maintenance of distraction 6. No dislodgement of the implant 7. No device-related complications |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Success Rate in Physical Function (PF) Domain of Zurich Claudication Questionnaire (ZCQ) | 6 weeks, 12months, 24 months, 36 months, 48 months, and 60 months | Success rate in PF domain of ZCQ is reported as percentage of participants who had success in PF domain of ZCQ. The PF success was defined as clinically significant improvement by at least 0.5 points in PF score compared to preoperative baseline. |
| Oswestry Disability Index (ODI) Score | Baseline, 6 weeks, 12 months, 24 months, 36 months, 48 months, and 60 months | ODI Questionnaire was used to assess patient back function. The ODI score ranges from 0-100. The best score is 0 (no disability) and worst is 100 (maximum disability). |
| General Health Status -- SF-36 PCS | Baseline, 6 weeks, 12 months, 24 months, 36 months, 48 months, and 60 months | The Medical Outcomes Study 36-Item Short Form Health Survey (SF-36) was used to assess general health status. The SF-36 results were summarized into two components, a physical component summary (PCS) and a mental component summary (MCS). The score for PCS is between 0 and 100, with higher scores denoting better quality of life. |
| General Health Status -- SF-36 MCS | Baseline, 6 weeks, 12 months, 24 months, 36 months, 48 months, and 60 months | MCS score is between 0 and 100, with higher scores denoting better quality of life. |
| Back Pain in Numerical Rating Scales (NRS) | Baseline, 6 weeks, 12 months, 24 months, 36 months, 48 months, and 60 months | Back pain was measured using NRS. Patients rated their back pain 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. |
| Left Leg Pain in Numerical Rating Scales (NRS) | Baseline, 6 weeks, 12 months, 24 months, 36 months, 48 months, and 60 months | Left leg pain was measured using NRS. Patients rated their leg pain 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. |
| Right Leg Pain in Numerical Rating Scales (NRS) | Baseline, 6 weeks, 12 months, 24 months, 36 months, 48 months, and 60 months | Right leg pain was measured using NRS. Patients rated their leg pain 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. |
| Treatment Success Rate at 60 Months | 60 months | Treatment success rate is reported as the percentage of participants who met all of the following criteria: 1. Clinically significant improvement (by at least 0.5 points) in the Symptom Severity (SS) domain of the ZCQ compared to preoperative baseline 2. Clinically significant improvement (by at least 0.5 points) in the Physical Function (PF) domain of the ZCQ compared to pre-operative baseline 3. Patient satisfaction with treatment defined as a Patient Satisfaction (PS) score \< 2.5 4. No additional surgery for lumbar stenosis performed 5. Maintenance of distraction 6. No dislodgement of the implant 7. No device-related complications |
| Symptom Severity (SS) Scores Measured by Zurich Claudication Questionnaire (ZCQ) | Baseline, 6 weeks, 12 months, 24 months, 36 months, 48 months, and 60 months | ZCQ is a validated outcomes instrument specific to lumbar spinal stenosis, and captures data in 3 distinct domains: SS, PF, and post-treatment PS. SS Score is based on seven questions (overall pain, pain frequency, pain in the back, pain in the leg, numbness, weakness, and balanced disturbance) in ZCQ. 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 1 to 5. A lower score represents a better outcome/condition. If more than two items were missing, the SS score was considered as missing. |
| Success Rate in Symptom Severity (SS) Domain of Zurich Claudication Questionnaire (ZCQ) | 6 weeks, 12months, 24 months, 36 months, 48 months, and 60 months | Success rate in SS domain of ZCQ is reported as percentage of participants who had success in SS domain of the ZCQ. The SS success was defined as clinically significant improvement by at least 0.5 point in SS score compared to preoperative baseline. |
| Physical Function (PF) Scores Measured by Zurich Claudication Questionnaire (ZCQ) | Baseline, 6 weeks, 12 months, 24 months, 36 months, 48 months, and 60 months | PF score is the mean score of five physical function questions of ZCQ, ranging from 1 to 4. A lower score represents a better outcome/condition. If more than one item were missing, the PF score was considered as missing. |
| Patient Satisfaction (PS) Scores Measured by Zurich Claudication Questionnaire (ZCQ) at Post Treatment | 6 weeks, 12 months, 24 months, 36 months, 48 months, and 60 months | PS score is the mean score of 6 questions of ZCQ, ranging from 1 to 4 if the number of responses exceeded four. A lower score represents a better outcome. Patients with PS score less than 2.5 at postoperative evaluation were considered positive, which implied that patients were satisfied with their treatment. |
| Success Rate in Patient Satisfaction (PS) Domain of Zurich Claudication Questionnaire (ZCQ) at Post Treatment | 6 weeks, 12months, 24 months, 36 months, 48 months, and 60 months | Success rate in PS domain of ZCQ at post treatment is reported as the percentage of participants who had success in PS domain of ZCQ. The PS success was defined as PS score less than 2.5. |
Other
| Measure | Time frame | Description |
|---|---|---|
| Percent of Subjects With Pfirrmann Grades Increased at Adjacent Levels at 24 Months | 24 months | The percent of subjects with Pfirrmann grades increased from baseline at adjacent levels at 24 months is reported. |
| Percent of Subjects With Pfirrmann Grades Increased at Adjacent Levels at 60 Months | 60 months | The percent of subjects with Pfirrmann grades increased from baseline at adjacent levels at 60 months is reported. |
| Percent of Subjects Who Reported Implant-Related Adverse Events | Overall study period | — |
| Percent of Subjects Who Had Any Subsequent Lumbar Spine Surgery | Overall study period | — |
| Percent of Subjects With Pfirrmann Grades Increased From Baseline at Any Index Level at 24 Months | 24 months | The Pfirrmann Grading System is descriptive and grades the status on an intervertebral disc as visualized with MRI using a 5-point system (grade I, II, III, IV or V). Grade I: disc is homogeneous with bright hyper-intense white signal intensity and normal disc height. Grade V: disc is inhomogeneous with hypo-intense black signal intensity and there is no more distinction between the nucleus and annulus, the disc space is collapsed. The percent of subjects with Pfirrmann grades increased from baseline at 24 months is reported. |
| Percent of Subjects With Pfirrmann Grades Increased From Baseline at Any Index Level at 60 Months | 60 months | The Pfirrmann Grading System is descriptive and grades the status on an intervertebral disc as visualized with MRI using a 5-point system (grade I, II, III, IV or V). Grade I: disc is homogeneous with bright hyper-intense white signal intensity and normal disc height. Grade V: disc is inhomogeneous with hypo-intense black signal intensity and there is no more distinction between the nucleus and annulus, the disc space is collapsed. The percent of subjects with Pfirrmann grades increased from baseline at 60 months is reported. |
Countries
United States
Participant flow
Recruitment details
Due to early study termination, the final analysis is consistent with the last annual report submission to the FDA and data reported on FDA's post-approval webpage reporting on 162 of 176 enrolled subjects.
Participants by arm
| Arm | Count |
|---|---|
| X-STOP PEEK In this arm, patients underwent X-STOP PEEK surgery. | 162 |
| Total | 162 |
Withdrawals & dropouts
| Period | Reason | FG000 |
|---|---|---|
| Overall Study | Death | 3 |
| Overall Study | Lost to Follow-up | 4 |
| Overall Study | Missing | 3 |
| Overall Study | Patient not due for visit | 76 |
| Overall Study | patient not over due | 6 |
| Overall Study | Withdrawal by Subject | 37 |
Baseline characteristics
| Characteristic | X-STOP PEEK |
|---|---|
| Age, Continuous | 71.5 years STANDARD_DEVIATION 8.4 |
| Body Mass Index | 29.3 kg/m^2 STANDARD_DEVIATION 4.72 |
| Height | 67.2 inches STANDARD_DEVIATION 3.93 |
| Race/Ethnicity, Customized American Indian or Alaska Native | 0 participants |
| Race/Ethnicity, Customized Asian | 1 participants |
| Race/Ethnicity, Customized Black or African American | 4 participants |
| Race/Ethnicity, Customized Caucasian | 152 participants |
| Race/Ethnicity, Customized Hispanic or Latino | 4 participants |
| Race/Ethnicity, Customized Native Hawaiian or other pacific islander | 1 participants |
| Race/Ethnicity, Customized Other | 0 participants |
| Sex: Female, Male Female | 75 Participants |
| Sex: Female, Male Male | 87 Participants |
| Weight | 188.0 lbs STANDARD_DEVIATION 37.4 |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | — / — |
| other Total, other adverse events | 118 / 162 |
| serious Total, serious adverse events | 65 / 162 |
Outcome results
Primary
Treatment Success Rate at 24 Months
Treatment success rate is reported as the percentage of participants who met all of the following criteria: 1. Clinically significant improvement (by at least 0.5 points) in the Symptom Severity (SS) domain of the Zurich Claudication Questionnaire (ZCQ) compared to preoperative baseline 2. Clinically significant improvement (by at least 0.5 points) in the Physical Function (PF) domain of the ZCQ compared to pre-operative baseline 3. Patient satisfaction with treatment defined as a Patient Satisfaction (PS) score \< 2.5 4. No additional surgery for lumbar stenosis performed 5. Maintenance of distraction 6. No dislodgement of the implant 7. No device-related complications
Time frame: 24 months
Population: At 24 months, 94 subjects were evaluable for overall treatment success. Once subjects failed on additional surgery for lumbar stenosis or dislodgement of the implant or device-related complications, they failed at later visits no matter whether they had data or not.
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| X-STOP PEEK | Treatment Success Rate at 24 Months | 30.9 percentage of participants |
Secondary
Back Pain in Numerical Rating Scales (NRS)
Back pain was measured using NRS. Patients rated their back pain 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.
Time frame: Baseline, 6 weeks, 12 months, 24 months, 36 months, 48 months, and 60 months
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| X-STOP PEEK | Back Pain in Numerical Rating Scales (NRS) | Back pain at baseline (n=161) | 6.4 units on a scale | Standard Deviation 2.4 |
| X-STOP PEEK | Back Pain in Numerical Rating Scales (NRS) | Back pain at 6 weeks (n=150) | 3.2 units on a scale | Standard Deviation 2.4 |
| X-STOP PEEK | Back Pain in Numerical Rating Scales (NRS) | Back pain at 12 months (n=103) | 3.5 units on a scale | Standard Deviation 2.8 |
| X-STOP PEEK | Back Pain in Numerical Rating Scales (NRS) | Back pain at 24 months (n=88) | 4.0 units on a scale | Standard Deviation 3 |
| X-STOP PEEK | Back Pain in Numerical Rating Scales (NRS) | Back pain at 36 months (n=70) | 3.7 units on a scale | Standard Deviation 2.9 |
| X-STOP PEEK | Back Pain in Numerical Rating Scales (NRS) | Back pain at 48 months (n=59) | 3.7 units on a scale | Standard Deviation 3.2 |
| X-STOP PEEK | Back Pain in Numerical Rating Scales (NRS) | Back pain at 60 months (n=46) | 3.5 units on a scale | Standard Deviation 3 |
Secondary
General Health Status -- SF-36 MCS
MCS score is between 0 and 100, with higher scores denoting better quality of life.
Time frame: Baseline, 6 weeks, 12 months, 24 months, 36 months, 48 months, and 60 months
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| X-STOP PEEK | General Health Status -- SF-36 MCS | SF-36 MCS at baseline (n=162) | 51.5 units on a scale | Standard Deviation 10.8 |
| X-STOP PEEK | General Health Status -- SF-36 MCS | SF-36 MCS at 6 weeks (n=150) | 54.6 units on a scale | Standard Deviation 9.5 |
| X-STOP PEEK | General Health Status -- SF-36 MCS | SF-36 MCS at 12 months (n=103) | 53.8 units on a scale | Standard Deviation 10.1 |
| X-STOP PEEK | General Health Status -- SF-36 MCS | SF-36 MCS at 24 months (n=88) | 53.4 units on a scale | Standard Deviation 11.1 |
| X-STOP PEEK | General Health Status -- SF-36 MCS | SF-36 MCS at 36 months (n=70) | 54.6 units on a scale | Standard Deviation 10.8 |
| X-STOP PEEK | General Health Status -- SF-36 MCS | SF-36 MCS at 48 months (n=58) | 54.1 units on a scale | Standard Deviation 11.9 |
| X-STOP PEEK | General Health Status -- SF-36 MCS | SF-36 MCS at 60 months (n=46) | 52.8 units on a scale | Standard Deviation 12.5 |
Secondary
General Health Status -- SF-36 PCS
The Medical Outcomes Study 36-Item Short Form Health Survey (SF-36) was used to assess general health status. The SF-36 results were summarized into two components, a physical component summary (PCS) and a mental component summary (MCS). The score for PCS is between 0 and 100, with higher scores denoting better quality of life.
Time frame: Baseline, 6 weeks, 12 months, 24 months, 36 months, 48 months, and 60 months
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| X-STOP PEEK | General Health Status -- SF-36 PCS | SF-36 PCS at baseline (n=162) | 27.1 units on a scale | Standard Deviation 6.8 |
| X-STOP PEEK | General Health Status -- SF-36 PCS | SF-36 PCS at 6 week (n=150) | 36.3 units on a scale | Standard Deviation 10.5 |
| X-STOP PEEK | General Health Status -- SF-36 PCS | SF-36 PCS at 12 months (n=103) | 38.4 units on a scale | Standard Deviation 12.2 |
| X-STOP PEEK | General Health Status -- SF-36 PCS | SF-36 PCS at 24 months (n=88) | 35.2 units on a scale | Standard Deviation 12 |
| X-STOP PEEK | General Health Status -- SF-36 PCS | SF-36 PCS at 36 months (n=70) | 36.4 units on a scale | Standard Deviation 12.5 |
| X-STOP PEEK | General Health Status -- SF-36 PCS | SF-36 PCS at 48 months (n=58) | 35.7 units on a scale | Standard Deviation 11.8 |
| X-STOP PEEK | General Health Status -- SF-36 PCS | SF-36 PCS at 60 months (n=46) | 35.6 units on a scale | Standard Deviation 12.6 |
Secondary
Left Leg Pain in Numerical Rating Scales (NRS)
Left leg pain was measured using NRS. Patients rated their leg pain 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.
Time frame: Baseline, 6 weeks, 12 months, 24 months, 36 months, 48 months, and 60 months
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| X-STOP PEEK | Left Leg Pain in Numerical Rating Scales (NRS) | Left leg pain at baseline (n=161) | 5.5 units on a scale | Standard Deviation 3 |
| X-STOP PEEK | Left Leg Pain in Numerical Rating Scales (NRS) | Left leg pain at 6 weeks (n=150) | 1.9 units on a scale | Standard Deviation 2.6 |
| X-STOP PEEK | Left Leg Pain in Numerical Rating Scales (NRS) | Left leg pain at 12 months (n=103) | 2.1 units on a scale | Standard Deviation 2.8 |
| X-STOP PEEK | Left Leg Pain in Numerical Rating Scales (NRS) | Left leg pain at 24 months (n=87) | 2.7 units on a scale | Standard Deviation 2.9 |
| X-STOP PEEK | Left Leg Pain in Numerical Rating Scales (NRS) | Left leg pain at 36 months (n=70) | 2.8 units on a scale | Standard Deviation 3 |
| X-STOP PEEK | Left Leg Pain in Numerical Rating Scales (NRS) | Left leg pain at 48 months (n=59) | 2.5 units on a scale | Standard Deviation 2.9 |
| X-STOP PEEK | Left Leg Pain in Numerical Rating Scales (NRS) | Left leg pain at 60 months (n=46) | 2.7 units on a scale | Standard Deviation 3.1 |
Secondary
Oswestry Disability Index (ODI) Score
ODI Questionnaire was used to assess patient back function. The ODI score ranges from 0-100. The best score is 0 (no disability) and worst is 100 (maximum disability).
Time frame: Baseline, 6 weeks, 12 months, 24 months, 36 months, 48 months, and 60 months
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| X-STOP PEEK | Oswestry Disability Index (ODI) Score | ODI score at baseline (n=162) | 38.81 units on a scale | Standard Deviation 14.11 |
| X-STOP PEEK | Oswestry Disability Index (ODI) Score | ODI score at 6 weeks (n=151) | 22.98 units on a scale | Standard Deviation 16.23 |
| X-STOP PEEK | Oswestry Disability Index (ODI) Score | ODI score at 12 months (n=103) | 20.34 units on a scale | Standard Deviation 16.27 |
| X-STOP PEEK | Oswestry Disability Index (ODI) Score | ODI score at 24 months (n=88) | 23.99 units on a scale | Standard Deviation 17.08 |
| X-STOP PEEK | Oswestry Disability Index (ODI) Score | ODI score at 36 months (n=71) | 23.04 units on a scale | Standard Deviation 17.23 |
| X-STOP PEEK | Oswestry Disability Index (ODI) Score | ODI score at 48 months (n=59) | 25.27 units on a scale | Standard Deviation 18.22 |
| X-STOP PEEK | Oswestry Disability Index (ODI) Score | ODI score at 60 months (n=46) | 24.88 units on a scale | Standard Deviation 18.53 |
Secondary
Patient Satisfaction (PS) Scores Measured by Zurich Claudication Questionnaire (ZCQ) at Post Treatment
PS score is the mean score of 6 questions of ZCQ, ranging from 1 to 4 if the number of responses exceeded four. A lower score represents a better outcome. Patients with PS score less than 2.5 at postoperative evaluation were considered positive, which implied that patients were satisfied with their treatment.
Time frame: 6 weeks, 12 months, 24 months, 36 months, 48 months, and 60 months
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| X-STOP PEEK | Patient Satisfaction (PS) Scores Measured by Zurich Claudication Questionnaire (ZCQ) at Post Treatment | PS score at 6 weeks (n=150) | 1.75 units on a scale | Standard Deviation 0.74 |
| X-STOP PEEK | Patient Satisfaction (PS) Scores Measured by Zurich Claudication Questionnaire (ZCQ) at Post Treatment | PS score at 12 months (n=103) | 1.78 units on a scale | Standard Deviation 0.75 |
| X-STOP PEEK | Patient Satisfaction (PS) Scores Measured by Zurich Claudication Questionnaire (ZCQ) at Post Treatment | PS score at 24 months (n=88) | 1.90 units on a scale | Standard Deviation 0.81 |
| X-STOP PEEK | Patient Satisfaction (PS) Scores Measured by Zurich Claudication Questionnaire (ZCQ) at Post Treatment | PS score at 36 months (n=70) | 1.84 units on a scale | Standard Deviation 0.81 |
| X-STOP PEEK | Patient Satisfaction (PS) Scores Measured by Zurich Claudication Questionnaire (ZCQ) at Post Treatment | PS score at 48 months (n=59) | 1.89 units on a scale | Standard Deviation 0.9 |
| X-STOP PEEK | Patient Satisfaction (PS) Scores Measured by Zurich Claudication Questionnaire (ZCQ) at Post Treatment | PS score at 60 months (n=46) | 1.91 units on a scale | Standard Deviation 0.9 |
Secondary
Physical Function (PF) Scores Measured by Zurich Claudication Questionnaire (ZCQ)
PF score is the mean score of five physical function questions of ZCQ, ranging from 1 to 4. A lower score represents a better outcome/condition. If more than one item were missing, the PF score was considered as missing.
Time frame: Baseline, 6 weeks, 12 months, 24 months, 36 months, 48 months, and 60 months
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| X-STOP PEEK | Physical Function (PF) Scores Measured by Zurich Claudication Questionnaire (ZCQ) | PF score at baseline (n=162) | 2.67 units on a scale | Standard Deviation 0.36 |
| X-STOP PEEK | Physical Function (PF) Scores Measured by Zurich Claudication Questionnaire (ZCQ) | PF score at 6 weeks (n=150) | 1.79 units on a scale | Standard Deviation 0.6 |
| X-STOP PEEK | Physical Function (PF) Scores Measured by Zurich Claudication Questionnaire (ZCQ) | PF score at 12 months (n=103) | 1.71 units on a scale | Standard Deviation 0.62 |
| X-STOP PEEK | Physical Function (PF) Scores Measured by Zurich Claudication Questionnaire (ZCQ) | PF score at 24 months (n=87) | 1.89 units on a scale | Standard Deviation 0.69 |
| X-STOP PEEK | Physical Function (PF) Scores Measured by Zurich Claudication Questionnaire (ZCQ) | PF score at 36 months (n=71) | 1.93 units on a scale | Standard Deviation 0.76 |
| X-STOP PEEK | Physical Function (PF) Scores Measured by Zurich Claudication Questionnaire (ZCQ) | PF score at 48 months (n=59) | 1.87 units on a scale | Standard Deviation 0.67 |
| X-STOP PEEK | Physical Function (PF) Scores Measured by Zurich Claudication Questionnaire (ZCQ) | PF score at 60 months (n=46) | 1.92 units on a scale | Standard Deviation 0.79 |
Secondary
Right Leg Pain in Numerical Rating Scales (NRS)
Right leg pain was measured using NRS. Patients rated their leg pain 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.
Time frame: Baseline, 6 weeks, 12 months, 24 months, 36 months, 48 months, and 60 months
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| X-STOP PEEK | Right Leg Pain in Numerical Rating Scales (NRS) | Right leg pain at 60 months (n=46) | 2.8 units on a scale | Standard Deviation 3.2 |
| X-STOP PEEK | Right Leg Pain in Numerical Rating Scales (NRS) | Right leg pain at baseline (n=161) | 5.5 units on a scale | Standard Deviation 3 |
| X-STOP PEEK | Right Leg Pain in Numerical Rating Scales (NRS) | Right leg pain at 6 weeks (n=150) | 2.0 units on a scale | Standard Deviation 2.5 |
| X-STOP PEEK | Right Leg Pain in Numerical Rating Scales (NRS) | Right leg pain at 12 months (n=103) | 2.4 units on a scale | Standard Deviation 2.7 |
| X-STOP PEEK | Right Leg Pain in Numerical Rating Scales (NRS) | Right leg pain at 24 months (n=88) | 2.9 units on a scale | Standard Deviation 3.1 |
| X-STOP PEEK | Right Leg Pain in Numerical Rating Scales (NRS) | Right leg pain at 36 months (n=70) | 2.3 units on a scale | Standard Deviation 2.7 |
| X-STOP PEEK | Right Leg Pain in Numerical Rating Scales (NRS) | Right leg pain at 48 months (n=59) | 2.7 units on a scale | Standard Deviation 3.2 |
Secondary
Success Rate in Patient Satisfaction (PS) Domain of Zurich Claudication Questionnaire (ZCQ) at Post Treatment
Success rate in PS domain of ZCQ at post treatment is reported as the percentage of participants who had success in PS domain of ZCQ. The PS success was defined as PS score less than 2.5.
Time frame: 6 weeks, 12months, 24 months, 36 months, 48 months, and 60 months
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| X-STOP PEEK | Success Rate in Patient Satisfaction (PS) Domain of Zurich Claudication Questionnaire (ZCQ) at Post Treatment | PS success at 6 weeks (n=150) | 81.3 percentage of participants |
| X-STOP PEEK | Success Rate in Patient Satisfaction (PS) Domain of Zurich Claudication Questionnaire (ZCQ) at Post Treatment | PS success at 12 months (n=103) | 80.6 percentage of participants |
| X-STOP PEEK | Success Rate in Patient Satisfaction (PS) Domain of Zurich Claudication Questionnaire (ZCQ) at Post Treatment | PS success at 24 months (n=88) | 72.7 percentage of participants |
| X-STOP PEEK | Success Rate in Patient Satisfaction (PS) Domain of Zurich Claudication Questionnaire (ZCQ) at Post Treatment | PS success at 36 months (n=70) | 72.9 percentage of participants |
| X-STOP PEEK | Success Rate in Patient Satisfaction (PS) Domain of Zurich Claudication Questionnaire (ZCQ) at Post Treatment | PS success at 48 months (n=59) | 67.8 percentage of participants |
| X-STOP PEEK | Success Rate in Patient Satisfaction (PS) Domain of Zurich Claudication Questionnaire (ZCQ) at Post Treatment | PS success at 60 months (n=46) | 69.6 percentage of participants |
Secondary
Success Rate in Physical Function (PF) Domain of Zurich Claudication Questionnaire (ZCQ)
Success rate in PF domain of ZCQ is reported as percentage of participants who had success in PF domain of ZCQ. The PF success was defined as clinically significant improvement by at least 0.5 points in PF score compared to preoperative baseline.
Time frame: 6 weeks, 12months, 24 months, 36 months, 48 months, and 60 months
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| X-STOP PEEK | Success Rate in Physical Function (PF) Domain of Zurich Claudication Questionnaire (ZCQ) | PF success at 6 weeks (n=150) | 70.7 percentage of participants |
| X-STOP PEEK | Success Rate in Physical Function (PF) Domain of Zurich Claudication Questionnaire (ZCQ) | PF success at 12 months (n=103) | 71.8 percentage of participants |
| X-STOP PEEK | Success Rate in Physical Function (PF) Domain of Zurich Claudication Questionnaire (ZCQ) | PF success at 24 months (n=87) | 59.8 percentage of participants |
| X-STOP PEEK | Success Rate in Physical Function (PF) Domain of Zurich Claudication Questionnaire (ZCQ) | PF success at 36 months (n=71) | 56.3 percentage of participants |
| X-STOP PEEK | Success Rate in Physical Function (PF) Domain of Zurich Claudication Questionnaire (ZCQ) | PF success at 48 months (n=59) | 61.0 percentage of participants |
| X-STOP PEEK | Success Rate in Physical Function (PF) Domain of Zurich Claudication Questionnaire (ZCQ) | PF success at 60 months (n=46) | 54.3 percentage of participants |
Secondary
Success Rate in Symptom Severity (SS) Domain of Zurich Claudication Questionnaire (ZCQ)
Success rate in SS domain of ZCQ is reported as percentage of participants who had success in SS domain of the ZCQ. The SS success was defined as clinically significant improvement by at least 0.5 point in SS score compared to preoperative baseline.
Time frame: 6 weeks, 12months, 24 months, 36 months, 48 months, and 60 months
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| X-STOP PEEK | Success Rate in Symptom Severity (SS) Domain of Zurich Claudication Questionnaire (ZCQ) | SS success at 6 weeks (n=150) | 78.0 percentage of participants |
| X-STOP PEEK | Success Rate in Symptom Severity (SS) Domain of Zurich Claudication Questionnaire (ZCQ) | SS success at 12 months (n=102) | 71.6 percentage of participants |
| X-STOP PEEK | Success Rate in Symptom Severity (SS) Domain of Zurich Claudication Questionnaire (ZCQ) | SS success at 24 months (n=87) | 62.1 percentage of participants |
| X-STOP PEEK | Success Rate in Symptom Severity (SS) Domain of Zurich Claudication Questionnaire (ZCQ) | SS success at 36 months (n=70) | 64.3 percentage of participants |
| X-STOP PEEK | Success Rate in Symptom Severity (SS) Domain of Zurich Claudication Questionnaire (ZCQ) | SS success at 48 months (n=59) | 61.0 percentage of participants |
| X-STOP PEEK | Success Rate in Symptom Severity (SS) Domain of Zurich Claudication Questionnaire (ZCQ) | SS success at 60 months (n=46) | 56.5 percentage of participants |
Secondary
Symptom Severity (SS) Scores Measured by Zurich Claudication Questionnaire (ZCQ)
ZCQ is a validated outcomes instrument specific to lumbar spinal stenosis, and captures data in 3 distinct domains: SS, PF, and post-treatment PS. SS Score is based on seven questions (overall pain, pain frequency, pain in the back, pain in the leg, numbness, weakness, and balanced disturbance) in ZCQ. 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 1 to 5. A lower score represents a better outcome/condition. If more than two items were missing, the SS score was considered as missing.
Time frame: Baseline, 6 weeks, 12 months, 24 months, 36 months, 48 months, and 60 months
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| X-STOP PEEK | Symptom Severity (SS) Scores Measured by Zurich Claudication Questionnaire (ZCQ) | SS score baseline (n=161) | 3.29 units on a scale | Standard Deviation 0.58 |
| X-STOP PEEK | Symptom Severity (SS) Scores Measured by Zurich Claudication Questionnaire (ZCQ) | SS score at 6 weeks (n=151) | 2.10 units on a scale | Standard Deviation 0.7 |
| X-STOP PEEK | Symptom Severity (SS) Scores Measured by Zurich Claudication Questionnaire (ZCQ) | SS score at 12 months (n=103) | 2.26 units on a scale | Standard Deviation 0.77 |
| X-STOP PEEK | Symptom Severity (SS) Scores Measured by Zurich Claudication Questionnaire (ZCQ) | SS score at 24 months (n=88) | 2.38 units on a scale | Standard Deviation 0.85 |
| X-STOP PEEK | Symptom Severity (SS) Scores Measured by Zurich Claudication Questionnaire (ZCQ) | SS score at 36 months (n=71) | 2.25 units on a scale | Standard Deviation 0.78 |
| X-STOP PEEK | Symptom Severity (SS) Scores Measured by Zurich Claudication Questionnaire (ZCQ) | SS score at 48 months (n=59) | 2.32 units on a scale | Standard Deviation 0.81 |
| X-STOP PEEK | Symptom Severity (SS) Scores Measured by Zurich Claudication Questionnaire (ZCQ) | SS score at 60 months (n=46) | 2.38 units on a scale | Standard Deviation 0.89 |
Secondary
Treatment Success Rate at 60 Months
Treatment success rate is reported as the percentage of participants who met all of the following criteria: 1. Clinically significant improvement (by at least 0.5 points) in the Symptom Severity (SS) domain of the ZCQ compared to preoperative baseline 2. Clinically significant improvement (by at least 0.5 points) in the Physical Function (PF) domain of the ZCQ compared to pre-operative baseline 3. Patient satisfaction with treatment defined as a Patient Satisfaction (PS) score \< 2.5 4. No additional surgery for lumbar stenosis performed 5. Maintenance of distraction 6. No dislodgement of the implant 7. No device-related complications
Time frame: 60 months
Population: At 60 months, 62 subjects were evaluable for overall treatment success. Once subjects failed on additional surgery for lumbar stenosis or dislodgement of the implant or device-related complications, they failed at later visits no matter whether they had data or not.
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| X-STOP PEEK | Treatment Success Rate at 60 Months | 24.2 percentage of participants |
Other Pre-specified
Percent of Subjects Who Had Any Subsequent Lumbar Spine Surgery
Time frame: Overall study period
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| X-STOP PEEK | Percent of Subjects Who Had Any Subsequent Lumbar Spine Surgery | 19.8 percentage of participants |
Other Pre-specified
Percent of Subjects Who Reported Implant-Related Adverse Events
Time frame: Overall study period
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| X-STOP PEEK | Percent of Subjects Who Reported Implant-Related Adverse Events | 11.1 percentage of participants |
Other Pre-specified
Percent of Subjects With Pfirrmann Grades Increased at Adjacent Levels at 24 Months
The percent of subjects with Pfirrmann grades increased from baseline at adjacent levels at 24 months is reported.
Time frame: 24 months
Population: At 24 months, 53 subjects were evaluable for Pfirrmann Grade assessment.
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| X-STOP PEEK | Percent of Subjects With Pfirrmann Grades Increased at Adjacent Levels at 24 Months | 9.4 percentage of participants |
Other Pre-specified
Percent of Subjects With Pfirrmann Grades Increased at Adjacent Levels at 60 Months
The percent of subjects with Pfirrmann grades increased from baseline at adjacent levels at 60 months is reported.
Time frame: 60 months
Population: At 60 months, 16 subjects were evaluable for Pfirrmann Grade assessment.
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| X-STOP PEEK | Percent of Subjects With Pfirrmann Grades Increased at Adjacent Levels at 60 Months | 25.0 percentage of participants |
Other Pre-specified
Percent of Subjects With Pfirrmann Grades Increased From Baseline at Any Index Level at 24 Months
The Pfirrmann Grading System is descriptive and grades the status on an intervertebral disc as visualized with MRI using a 5-point system (grade I, II, III, IV or V). Grade I: disc is homogeneous with bright hyper-intense white signal intensity and normal disc height. Grade V: disc is inhomogeneous with hypo-intense black signal intensity and there is no more distinction between the nucleus and annulus, the disc space is collapsed. The percent of subjects with Pfirrmann grades increased from baseline at 24 months is reported.
Time frame: 24 months
Population: At 24 months, 53 subjects were evaluable for Pfirrmann Grade assessment.
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| X-STOP PEEK | Percent of Subjects With Pfirrmann Grades Increased From Baseline at Any Index Level at 24 Months | 9.4 percentage of participants |
Other Pre-specified
Percent of Subjects With Pfirrmann Grades Increased From Baseline at Any Index Level at 60 Months
The Pfirrmann Grading System is descriptive and grades the status on an intervertebral disc as visualized with MRI using a 5-point system (grade I, II, III, IV or V). Grade I: disc is homogeneous with bright hyper-intense white signal intensity and normal disc height. Grade V: disc is inhomogeneous with hypo-intense black signal intensity and there is no more distinction between the nucleus and annulus, the disc space is collapsed. The percent of subjects with Pfirrmann grades increased from baseline at 60 months is reported.
Time frame: 60 months
Population: At 60 months, 16 subjects were evaluable for Pfirrmann Grade assessment.
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| X-STOP PEEK | Percent of Subjects With Pfirrmann Grades Increased From Baseline at Any Index Level at 60 Months | 0.0 percentage of participants |