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| General |
| Study Status |
Ongoing |
Application Number /
Requirement Number |
P160036 / PAS001 |
| Date Original Protocol Accepted |
11/29/2019
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| Date Current Protocol Accepted |
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| Study Name |
Hintermann Series H3 TAR Long Term Study
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| Device Name |
Hintermann Series H3 Total Ankle Replacement System
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| General Study Protocol Parameters |
| Study Design |
Prospective Cohort Study
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| Data Source |
Other Data Source
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| Comparison Group |
Historical Control
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| Analysis Type |
Analytical
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| Study Population |
Adult: >21
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| Detailed Study Protocol Parameters |
| Study Objectives |
The objective of this single-center, single arm study is to determine the 10-year survivorship and effectiveness of total ankle arthroplasty using the H3 TAR System in comparison to historical literature controls for a legally marketed mobile bearing ankle.
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| Study Population |
Primary Safety and Effectiveness Cohort from the PMA
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| Sample Size |
All living subjects (n=298) from the Updated PSE cohort that were included in the PMA will continue to be followed until they reach the 10-year postoperative interval.
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| Key Study Endpoints |
The primary effectiveness measurement for this study is a composite of the following parameters:
AOFAS Score
Survivorship (absence of removal/revisions to include polyethylene revision),
Percentage of subjects with a serious device-related adverse event other than a revision or removal.
The primary safety endpoint for this study is the evaluation of reoperations, revisions, or removals of the H3 device occurring within 10 years of surgery.
Additional study endpoints are:
Incidence, occurrence, and types of serious device-related adverse events.
Nature, onset, duration, severity, relationship to the device, and relationship to the operative procedure and outcome of any adverse event.
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| Follow-up Visits and Length of Follow-up |
10 years
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| Interim or Final Data Summary |
| Actual Number of Patients Enrolled |
280 patients enrolled from the Primary Safety & Effectiveness cohort
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| Actual Number of Sites Enrolled |
One (1) site
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| Patient Follow-up Rate |
The follow-up rates were 81.3% (209/257) at 5 years and 78.5% (172/219) at 10 years for subjects with any data; and 30.4% (78/257) at 5 years and 44.3% (97/219) at 10 years for subjects with all data per protocol.
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| Final Safety Findings |
The following results are based on the 10-year Kaplan-Meier analysis. The estimated 10-year removal/revision rate for any metal components was 14.9% (95% CI: 10.5%, 21.0%). The 5-year rate was 6.5% (95% CI: 4.0%, 10.4%). The estimated 10-year removal/revision rate for polyethylene only components was 19.8% (95% CI: 15.1%, 25.8%). The 5-year rate was 13.6% (95% CI: 9.9%, 18.5%). When including metal and polyethylene components, the estimated 10-year removal/revision rate was 31.8% (95% CI: 26.0%,38.4%). The 5-year rate was 19.2% (95% CI:14.9%, 24.5%).
At 10-years post-implantation, 14.6% of subjects reported a serious, device-related adverse event other than a removal or revision.
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| Final Effect Findings |
AOFAS Scores (mean +/- SD): Baseline: 39.3 +/- 12.3 points; 5 years: 79.9 +/- 16.3 points (improvement of 40.1 points); 10 years: 77.2 +/- 17.7 points (improvement of 36.6 +/- 20.63 points).
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| Study Strengths & Weaknesses |
Strengths: The study was a continued follow-up of the premarket cohort with the intent to follow 280 subjects for 10 years post-implantation. The Kaplan-Meier analysis rates are based on a statistical calculation of the probability of device component removal or revision using the available time to additional surgery data of patients enrolled in the study.
Weaknesses: All subjects were enrolled at a single center located outside the US with approximately 80% of implantations performed by the same surgeon, which may limit the generalizability of the study results to US patients and US clinical practice. The study had loss to follow-up or missing data for 69.6% (179/257) of subjects at 5 years and 55.7% (122/219) of subjects at 10 years.
Due to safety concerns (i.e. higher than expected polyethylene (plastic) component fracture) with other available mobile bearing ankle devices, it was not feasible or appropriate in the final report to construct a Performance Goal (PG) as stated in the P160036 Condition of Approval (CoA) for this study. Therefore, the objective of using hypothesis testing to determine the 10-year survivorship and effectiveness of the H3 TAR System in comparison with historical literature controls for other available mobile bearing ankle devices could not be performed as required in the CoA. Hence, the change to the PAS study design (i.e., from hypothesis testing to descriptive analysis) was the most appropriate way to evaluate the final results.
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| Recommendations for Labeling Changes |
A labeling change is recommended to update the device labeling with the final study results to help ensure that patients and providers are aware of the long-term risk of device failure.
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