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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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Study Status Progress Adequate
Application Number P190009 / PAS001
Date Current Protocol Accepted  
Study Name TFAOS PAS
General Study Protocol Parameters
Study Design Prospective Cohort Study
Data Source Other Data Source
Comparison Group Objective Performance Criterion
Analysis Type Analytical
Study Population Adult: >21
Detailed Study Protocol Parameters
Study Design Description The Transfemoral Amputation Osseointegration Study (TFAOS) initiated on November 11, 2017 and is sponsored by the Henry Jackson Foundation. The sponsor of TFAOS has agreed to provide the data to Integrum, who will analyze the data consistent with FDA’s requested endpoints and then submit reports to the agency.

The TFAOS is a prospective, multicenter, cohort study to provide an ongoing assessment of the short-term (2 years) safety and effectiveness outcomes of the updated version of the OPRATM Implant system (e.g., improvements with components, AxorTM II, and instrumentation since the H080004 pivotal study).
Study Population Description Patients who have the OPRATM implant procedure performed at Walter Reed or Univeristy of California San Francisco (UCSF) and meet the eligibility criteria established in the study protocol.
Sample Size The sample size of 50 patients in the TFAOS study was calculated to power the primary endpoint in the study, i.e., the change in prosthetic use score. A sample size of 50 patients is also sufficient for the primary endpoints in the PAS analysis. With an alpha of 0.05, 50 subjects have >80% power to demonstrate that each primary endpoint result will be greater than 50%, assuming 70% success.
Data Collection Primary Endpoints
1. Rate of overall success at 2 years. The overall success is the composite primary safety and effectiveness endpoint.
a. Primary safety endpoint: Proportion of patients with no subsequent secondary surgical interventions and, at most, 2 superficial infections, at 2 years.
b. Primary effectiveness endpoint: Proportion of patients who achieve the minimally clinically important difference (MCID) for the total Q-TFA score (mean of all subscores, i.e., prosthetic use score, prosthetic mobility score, problem score, and global score) of 20.25 points, and radiographic success, defined as no radiographic loosening of the implant with a radiolucent zone wider than the thread depth surrounding the entire implant.
2. Proportion of patients who achieved either/or/none of primary safety endpoint or primary effectiveness endpoint at 2 years.

Secondary Endpoints
Proportion of patients who achieved the MCID for the Q-TFA prosthetic use score (19 points), prosthetic mobility score (11 points), problem score (-23 points), and global score (33 points), individually at 2 years after stage-2 surgery.
Change in each of total Q-TFA score, Q-TFA prosthetic use score, prosthetic mobility score, problem score and global score from baseline to 2 years after stage-2 surgery.
Follow-up Visits and Length of Follow-up 2 years after Stage 2 Surgery
Interim or Final Data Summary
Interim Safety Information No serious or unanticipated adverse events were reported during this reporting period.
The available data (preliminary results) to date demonstrate the safety and effectiveness of the OPRA device approved in the PMA.
Actual Number of Patients Enrolled 50 (Enrollment completed)
Actual Number of Sites Enrolled 2 (Walter Reed & UCSF)
Patient Follow-up Rate 46% (23/50)

TFAOS PAS Schedule

Report Schedule
Date Due
FDA Receipt
Applicant's Reporting Status
6 month report 06/18/2021 07/08/2021 Overdue/Received
1 year report 12/18/2021 12/30/2021 Overdue/Received
18 month report 06/18/2022 06/28/2022 Overdue/Received
2 year report 12/18/2022    
3 year report 12/18/2023    
4 year report 12/17/2024    

Contact Us

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

Additional Resources