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| General |
| Study Status |
Completed |
| 522 Number / Requirement Number |
PS110038 / PSS001 |
| Date Original Plan Accepted |
09/28/2012
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| Date Current Plan Accepted |
09/22/2013
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| Study Name |
Metal ion levels
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| Device Name |
Depuy pinnacle metal-on-metal acetabular cup liners
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| Root Document Number |
K080991
K003523
K073413
K070359
K082239
K040627
K093646
K083642
K002883
K023786
K062426
K090998
K073570
K070554
K042992
K061221
K082585
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| General Study Protocol Parameters |
| Study Design |
Cross-Sectional Study
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| Data Source |
New Data Collection
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| Comparison Group |
No Control
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| Analysis Type |
Analytical
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| Study Population |
Transit. Adolescent B (as adults) : 18-21 yrs,
Adult: >21
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| Detailed Study Protocol Parameters |
| Study Objectives |
"Metal ions and ALTR assessed in cross-sectional multi-center manner. It is anticipated that most subjects will only require one visit; subjects that have an ALTR or possible ALTR diagnosed will be followed for one year or until revision, whichever occurs first.
The primary objective of this clinical evaluation is to estimate chromium and cobalt blood ion levels (serum and whole blood) in the patient population from pre-operatively through 8 years post-operatively. Means for each year, pre-op through 8 years (5 years for the ASR) will be summarized with summary statistics and 95% confidence intervals.
Null Hypothesis Ho: The ion level means at pre-op and each year 1 through 8 years (ASR: 2 through 6 years) post-operatively are all identical
Alternative Hypothesis Ha: The ion level means at pre-op and each respective post-operative time period in the analysis are not all identical"
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| Study Population |
Patients who received Pinnacle and ASR total hips
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| Sample Size |
Pinnacle arm: 9 sites, 250 patients; ASR Arm 6 sites, 150 patients
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| Key Study Endpoints |
Cobalt and chromium ions, Adverse Local Tissue Reactions (ALTR), clinical (incl. Harris hip score), radiographic, MARS MRI
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| Follow-up Visits and Length of Follow-up |
None for most patients; up to 1 year of follow-up for ALTR patients
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| Interim or Final Data Summary |
| Interim Results |
completed
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| Actual Number of Patients Enrolled |
Actual number of subjects enrolled: 256 (50 pre-operative controls; 206 post-op and 203 non- revised at consent) for the Pinnacle study. For the ASR study there were 135 post-op subjects and 101 non-revised subjects at consent. The same pre-operative control group from the Pinnacle study was employed in the ASR study.
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| Actual Number of Sites Enrolled |
Actual number of study sites enrolled: 8 for the Pinnacle study and 7 for the ASR study.
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| Patient Followup Rate |
Not applicable in general as the study design was cross-sectional.
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| Final Safety Findings |
Pinnacle Study - An appreciable increase in mean and median metal ion levels was noted comparing post-operative and pre-operative levels. No clear patterns or trend was observed over the time span of 1 to 8 years post-op. Chromium whole blood, chromium serum, cobalt whole blood and
cobalt serum levels were all appreciably greater in bilateral metal-on-metal hip patients than in their unilateral metal-on-metal hip counterparts. Chromium whole blood, chromium serum, cobalt whole blood and cobalt serum levels were all significantly greater in metal-on-metal hip patients with an assessment of adverse local tissue reaction than in their counterparts without an assessment of adverse local tissue reaction.
In total, there were 49 (24%, 95% CI: 18%, 31%) subjects on initial screening that had the determination of “Suggestive of adverse local tissue reaction (ALTR)”. A total of 10 of 49 (20%, 95%CI: 10%, 34%) patients who were suggestive of ALTR underwent revision in 1 year of follow- up. The estimated mean was higher (not statistically significant though) for each metal ion for unrevised subjects who were exhibiting pain or functional symptoms for the Harris Hip Score compared to unrevised subjects who did not exhibit pain or functional symptoms for both the initial metal ion level and the highest recorded value.
The average metal ion levels were generally higher, not necessarily statistically significant, in subjects who experienced at least one operative site adverse event or complication compared to subjects who did not experience an operative site adverse event or complication.
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| Final Effectiveness Findings |
The majority of metal-on-metal hip patients in the study had Harris Hip Scores, a recognized measure of device effectiveness, in the good to excellent range.
ASR Study - An appreciable increase in mean and median metal ion levels was noted comparing post-operative and pre-operative levels. No clear patterns or trend was observed over the time span of 4 to 6 years post-op. Chromium whole blood, chromium serum, cobalt whole blood and cobalt serum levels were all appreciably greater in bilateral metal-on-metal hip patients than in their unilateral metal-on-metal hip counterparts. Chromium whole blood, chromium serum, cobalt whole blood and cobalt serum levels were all significantly greater in metal-on-metal hip patients with an assessment of adverse local tissue reaction than in their counterparts without an assessment of adverse local tissue reaction.
In total, there were 46 (46%, 95%CI: 36%, 56%) subjects that had the determination of “Suggestive of ALTR’; 14 of the 46 (30%, 95%Ci: 18%, 46%) underwent a revision within one year of the determination. The reasons for revision could be categorized into two main areas: post-operative hip pain and revision due to ALTR. The estimated mean was higher for each metal ion for subjects who were revised compared to subjects who were not revised, although the results were not statistically significant possibly due to small sample size.
The average ion levels were generally higher in subjects who experienced at least one operative site adverse event or complication compared to subjects who did not experience an operative site adverse event or complication.
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| Study Strengths and Weaknesses |
A major strength of the overall study is the use of MRI examination, the gold standard, to detect adverse local tissue reaction (ALTR). A weakness of the study is its cross-sectional nature, with the absence of long-term follow-up of individual patients. For the ASR™-XL system, only 4- 6 years post-op data were collected for the cross-sectional data analysis. Of note, metal ion levels and clinical symptoms were both factored into the determination of the ALTR, therefore, any observed association between metal ion levels and the occurrence of ALTR in this study needs to be interpreted with caution.
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| Recommendations for Labeling Changes |
no labeling change is recommended since the devices are no longer marketed in the US.
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