|
General |
Study Status |
Completed |
Application Number / Requirement Number |
P050016 / PAS001 |
Date Original Protocol Accepted |
07/03/2007
|
Date Current Protocol Accepted |
11/04/2008
|
Study Name |
Long Term Study
|
Device Name |
CORMET HIP RESURFACING SYSTEM
|
General Study Protocol Parameters |
Study Design |
Prospective Cohort Study
|
Data Source |
New Data Collection
|
Comparison Group |
No Control
|
Analysis Type |
Analytical
|
Study Population |
Transit. Adolescent B (as adults) : 18-21 yrs,
Adult: >21
|
Detailed Study Protocol Parameters |
Study Objectives |
The study is a multi-center, non-randomized, cohort study, which includes the extended follow-up of the premarket cohort.
|
Study Population |
Study population is as per device indication.
|
Sample Size |
The sample size is up to 448 patients.
|
Key Study Endpoints |
Data collection includes patient demographic data and medical history. A functional evaluation will be performed including a Harris Hip Score. Radiographic examination will encompass anteroposterior (AP) and lateral plain film studies.
|
Follow-up Visits and Length of Follow-up |
Patients will receive clinical and radiographic examination at 3, 4, 5, 8 and 10 postoperative years. In addition, patients will receive brief questionnaires at 6, 7, and 9 postoperative years. 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.
|
Interim or Final Data Summary |
Interim Results |
At 60 post-operative months, 94.5% of study participants attained a good-excellent Harris Hip Score.. Reported serious adverse events in the study population included 1 case of femoral fracture, 1 case of acetabular component loosening, and 1 case of dislocation.
|
Actual Number of Patients Enrolled |
A total of 258 hips in 231 subjects were enrolled in the study.
|
Actual Number of Sites Enrolled |
A total of 5 study sites were enrolled.
|
Patient Follow-up Rate |
The follow-up rate was 81.7% at 10 post-operative years
|
Final Safety Findings |
Female gender and relatively smaller component size were risk factors for device revision. Metal ion results at 5+ post-operative years were as follows: mean whole blood cobalt: 2.509 microg/L and mean whole blood chromium: 2.408 microg/L.
|
Final Effect Findings |
Calculated composite clinical success at 10 post-operative years was 88.2% without imputation and 73.2% with imputation.
|
Study Strengths & Weaknesses |
Study strengths included the use of the Harris Hip Score, a recognized and validated measure of device performance and the use of radiographic examination that allowed the detection of adverse events that are not detectable on history and physical examination. An important weakness of the post-approval study was the limited number of patients who received the device because of an underlying diagnosis other than osteoarthritis (e.g. avascular necrosis).
|
Recommendations for Labeling Changes |
The label of the device should be revised to include the results of this post-approval study
|