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U.S. Department of Health and Human Services

Post-Approval Studies (PAS) Database

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The FDA has the authority to require sponsors to perform a post-approval study (or studies) at the time of approval of a premarket approval (PMA), humanitarian device exemption (HDE), or product development protocol (PDP) application. Post-approval studies can provide patients, health care professionals, the device industry, the FDA and other stakeholders information on the continued safety and effectiveness (or continued probable benefit, in the case of an HDE) of approved medical devices. This database allows you to search Post-Approval Study information by applicant or device information.

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The TOPS System Continued F/U Study

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Study Status Ongoing
Application Number /
Requirement Number
P220002 / PAS001
Date Original Protocol Accepted 08/11/2023
Date Current Protocol Accepted  
Study Name The TOPS System Continued F/U Study
Device Name TOPS™ System
General Study Protocol Parameters
Study Design Randomized Clinical Trial
Data Source New Data Collection
Comparison Group Concurrent Control
Analysis Type Analytical
Study Population Adult: >21
Detailed Study Protocol Parameters
Study Objectives The purpose of this prospective, randomized, concurrently controlled, multi-center study is to evaluate the safety and effectiveness of the TOPS™ System versus to lumbar spinal fusion control.
Study Population Participants in the IDE study who failed at least 6 months of conservative therapy for treatment of leg pain with or without back pain at one vertebral level between L2 and L5 stemming from (1) moderate to severe central, foraminal, and/or subarticular recess lumbar spinal stenosis (LSS) and (2) up to Grade I degenerative spondylolisthesis or equivalent retrolisthesis and (3) thickening of the ligamentum flavum or scaring facet joint capsule.
Sample Size A total of 299 subjects in the Per Protocol analysis set (206 TOPS, 93 fusion control) who were enrolled into the Pivotal study and are continuing follow up to 5 years. Assuming 85% compliance, it implies 175 TOPS subjects and 79 Fusion controls. If compliance in controls is only 80%, this implies a control sample size of 74.
Key Study Endpoints Primary Effectiveness Endpoint:
The primary effectiveness endpoint is a composite clinical success (CCS) responder endpoint based on clinical status at Month 60. An individual subject will be regarded as achieving Month 60 CCS only if s/he meets all of the following criteria at 60-months compared to baseline:
A reduction of 15 points or more in the 60-month Oswestry Disability Index (ODI) compared to baseline;
No new or worsening, persistent neurologic deficit;
No epidural steroid injection, facet joint injections, nerve block procedures or implantable spinal cord stimulator to treat back or leg pain symptoms at any lumbar level;
Any TOPS subject will be considered a failure if fusion occurs as defined in the radiographic protocol. Any Fusion subject will be considered a failure if fusion (as defined in the radiographic protocol) does not occur. This assessment will be made by a core lab;
No revision or removal of implants;
No supplemental fixation at the index level or at the immediately adjacent levels;
No occurrence of a major device related adverse event.
Secondary Endpoints:
Individual components of 60-month composite clinical success (CCS);
CCS at Months 36 and 48;
ODI, changes from baseline in ODI, and 15 point improvement in ODI;
Visual analog scale (VAS) for back pain and worse leg pain, changes from baseline in VAS, and 20 mm improvement in VAS; for VAS, the higher of the two leg scores at baseline will be used for analysis purposes.
ZCQ findings;
o Improvement of greater than or equal to 0.5in ZCQ physical symptom score and symptom severity and less than or equal to 2.5 on ZCQ subject satisfaction over time.
o Overall ZCQ success defined as meeting all 2 of 3 individual ZCQ success criteria.
o Overall ZCQ success defined as meeting all three individual ZCQ success criteria.
Reduction in physical component score on SF-12;
Time to revision or removal, or supplemental fixation at index or adjacent level;
Narcotics use for lower back pain and leg pain;
Range of motion in flexion/extension at the index and immediately adjacent levels
Safety Endpoint:
Evaluation of the incidence and severity of complications and adverse reactions associated with the treatment.
The following AE listings will be constructed:
All AEs Sorted by Group and Event Type
All AEs Sorted by Group and Subject
Serious AEs
Severe AEs
Device Related AEs
Serious Device Related AEs
Severe Device Related AEs
Severe Life-Threatening AEs
Procedure Related AEs
Other AEs
AEs among subjects discontinued early
AEs among subjects who died.
Follow-up Visits and Length of Follow-up After 24-month follow-up visit, the subject will continue to be followed long term annual post 24 months, at 36, 48, until patient reaches 60 months.
60 months (5 years) post-implant

The TOPS System Continued F/U Study Reporting Schedule

Reporting Schedule
Date Due
FDA Receipt
Applicant's Reporting Status
6 month report 12/14/2023 12/22/2023 Overdue/Received
1 year report 06/14/2024    
2 year report 06/14/2025    
3 year report 06/14/2026    
final report 09/27/2027    

Contact Us

Mandated Studies Program
Food and Drug Administration
10903 New Hampshire Ave.
Silver Spring, MD 20993-0002
Email: MandatedStudiesPrograms@fda.hhs.gov

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