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

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

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.

Study Overview

• Status: Completed
• Conditions: Lumbar Spinal Stenosis
• Intervention / Treatment: Device: X STOP® Interspinous Process Decompression System

Detailed Description

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.

• Study Type: Observational
• Enrollment (Actual): 69

Contacts and Locations

Study Locations

• United States
  • California
    • San Francisco, California, United States, 94117
      • St. Mary's Spine Center
  • Maine
    • Scarborough, Maine, United States, 04074
      • Neurological & Spine Associates
  • Maryland
    • Timonium, Maryland, United States, 21093
      • Greater Baltimore Spine Care
  • Virginia
    • Norfolk, Virginia, United States, 23510
      • Neurological Specialist
  • Wisconsin
    • Madison, Wisconsin, United States, 53792
      • University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 50 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Patients who received implants and completed participation in the Pivotal, CAP, or COS studies and has the implant intact and is willing and able to provide consent and return to the clinic for evaluation or complete study questionnaires.

Description

Inclusion Criteria:

A patient will be admitted into the LTOS program if he/she meets all of the following inclusion criteria:

1. 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.
2. Is willing and able to provide Informed Consent
3. 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:

1. Participated in the Pivotal Trial as part of the X STOP group, but the device has been removed.
2. Participated in the CAP or COS programs, but the device has been removed.

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Other

What is the study measuring?

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

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Patients With Subsequent Lumbar Spinal Surgeries That Occurred During the Study	The surgeries that occurred subsequent to the original X-STOP implantation were categorized as revision, removal, reoperation, supplemental fixation, and other.	3+ years following first 2 years post-X-STOP implant through IDE study
Number of Patients With Device/Procedure Related Adverse Events That Occurred During the Study		3+ years following first 2 years post-X-STOP implant through IDE study

Collaborators and Investigators

• Sponsor: Medtronic Spine LLC

Publications and helpful links

General Publications

• Zucherman JF, Hsu KY, Hartjen CA, Mehalic TF, Implicito DA, Martin MJ, Johnson DR 2nd, Skidmore GA, Vessa PP, Dwyer JW, Puccio ST, Cauthen JC, Ozuna RM. A multicenter, prospective, randomized trial evaluating the X STOP interspinous process decompression system for the treatment of neurogenic intermittent claudication: two-year follow-up results. Spine (Phila Pa 1976). 2005 Jun 15;30(12):1351-8. doi: 10.1097/01.brs.0000166618.42749.d1.
• Hsu KY, Zucherman JF, Hartjen CA, Mehalic TF, Implicito DA, Martin MJ, Johnson DR 2nd, Skidmore GA, Vessa PP, Dwyer JW, Cauthen JC, Ozuna RM. Quality of life of lumbar stenosis-treated patients in whom the X STOP interspinous device was implanted. J Neurosurg Spine. 2006 Dec;5(6):500-7. doi: 10.3171/spi.2006.5.6.500.

Study record dates

Study Major Dates

• Study Start: December 1, 2006
• Study Completion (Actual): June 1, 2010

Study Registration Dates

• First Submitted: September 20, 2007
• First Submitted That Met QC Criteria: September 21, 2007
• First Posted (Estimate): September 24, 2007

Study Record Updates

• Last Update Posted (Actual): January 5, 2021
• Last Update Submitted That Met QC Criteria: December 10, 2020
• Last Verified: March 1, 2015

More Information

Terms related to this study

• Keywords: Lumbar Spinal Stenosis; X STOP
• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Pathological Conditions, Anatomical; Spinal Diseases; Bone Diseases; Constriction, Pathologic; Spinal Stenosis
• Other Study ID Numbers: LSS-004-LTO