In January 2005, the oversight responsibility of the Post-Approval Studies Program was transferred to the Division of Epidemiology (DEPI) of the Office of Surveillance and Biometrics (OSB)/Center for Devices and Radiological Health (CDRH).
The CDRH Post-Approval Studies Program encompasses design, tracking, oversight, and review responsibilities for studies mandated as a condition of approval of a premarket approval (PMA) application, protocol development product (PDP) application, or humanitarian device exemption (HDE) application. The program helps ensure that well-designed post-approval studies (PAS) are conducted effectively and efficiently and in the least burdensome manner.
CDRH has established an automated, internal tracking system that efficiently identifies the reporting status of active PAS studies ordered since January 1, 2005 based on study timelines incorporated in study protocols and agreed upon by the CDRH and applicants. This system represents CDRH's effort to ensure that all PAS commitments are fulfilled in a timely manner.
In addition, CDRH launched this publicly available webpage to keep all stakeholders informed of the progress of each PAS. The webpage displays general information regarding each PAS, as well as the overall study status (based on protocol-driven timelines and the adequacy of the data) and the applicant's reporting status for each submission due.
Transit. Adolescent B (as adults) : 18-21 yrs,
Detailed Study Protocol Parameters
Study Design Description
The study is a multi-center, prospective cohort study. The first null hypothesis of the study
is that the 24 month cumulative revision rate is more than 0.126. The second null hypothesis is that the 24 month composite clinical success rate is less than 0.81.
Study Population Description
Study population is as per device indication.
The sample size is 160 procedures.
For both primary efficacy endpoints (freedom from revision and composite clinical success), the primary objective
will be met by way of estimation using 95% exact binomial confidence intervals. Device survival will be illustrated by life tables and the plotting of a Kaplan-Meier curve.
Followup Visits and Length of Followup
Patients will be evaluated preoperatively, and at 6 weeks, 6 months, 12 months and 24
months postoperatively. The length of patient follow-up is two years.
Final Study Results
Actual Number of Patients Enrolled
A total of 147 patients and 160 hips were enrolled in the study.
Actual Number of Sites Enrolled
A total of six study sites enrolled patients into the study.
Patient Followup Rate
Follow-up in the study was 81.8% at 24+months.
Final Safety Findings
The percentage of study subjects who achieved Composite Clinical Success (CCS), 92.5%, in the unilateral
analysis groups for the Post-Approval (PAS) study was higher than that for the Pre-Market study,
Final Effectiveness Findings
A pronounced increased in Harris Hip Scores, a measure of device effectiveness, was observed post-
operatively. The mean Harris Hip Score pre-operatively was 53.9 for unilateral patients and 60.2 for bilateral patients. The mean Harris Hip Score at 24+ post-operative months was 96.1 for unilateral patients and 93.5 for bilateral patients.
Study Strengths and Weaknesses
A strength of the study was that it was appropriately powered for the study endpoints.
An additional strength of the study was the fact that a broad cross-section of clinical sites participated in the study. A study weakness was the absence of a concurrent control group.
Recommendations for Labeling Changes
Labeling changes are recommended. The sponsor should be instructed to submit a labeling change supplement
for the post-approval study that encompasses the findings regarding the post-approval study that are delineated above.