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|
| General |
| Study Status |
Completed |
| 522 Number / Requirement Number |
PS110005 / PSS001 |
| Date Original Plan Accepted |
02/13/2012
|
| Date Current Plan Accepted |
06/14/2013
|
| Study Name |
Metal Ion Levels
|
| Device Name |
Porous titanium acetabular augments, m2a magnum 12/14 taper inserts and one-piece modular heads
|
| Root Document Number |
K052888
K061423
K062994
K062995
K063002
K063514
K070274
K073637
K062998
K993438
K002379
K011110
K042037
K042774
K042841
K050124
K043547
K082446
K090757
K050251
K050441
K093235
K852351
|
| General Study Protocol Parameters |
| Study Design |
Cross-Sectional 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 |
A cross-sectional study to evaluate metal ions and ALTR among cohorts of patients established for each year post implant for metal ion level evaluation. Patients from each cohort, defined by the number of years post implant, will have a one-time assessment on metal ion levels. The objectives of the Metal Ion Levels studies focus on determining whether the presence of high blood and serum cobalt and chromium ion concentrations generally increase over time and if those concentrations are related to increased pain, adverse local tissue reactions (ALTRs), or revision; they also include analyses of explanted devices and the adverse events collected on study subjects.
|
| Study Population |
Patients who have received one of two Biomet implant types; a MOP primary THA or Biomet MOM primary THA devices (M2a Ringloc, M2a Taper, M2a 38 or the M2a Magnum) and who are not contraindicated for MRI.
|
| Sample Size |
Approximately 308 to 436 patients at five centers
|
| Key Study Endpoints |
For Postoperative Group patients only, the data listed below will be collected: Patient-reported outcomes. Harris Hip Score and hip physical exam. Patient questionnaire to collect contact information for follow-up. Patient questionnaire to collect occupational and/or environmental exposures to metal ions, general medical and physical history and description of any problems or pain. For Postoperative Group patients only, the following tests will also be performed: MRI - Magnetic Resonance Imaging will be utilized to determine the presence of soft tissue changes. Radiographic evaluation: cross-table lateral and AP films will be taken to assess component position and determine the presence of any radiographic changes. Metal Ion Testing: levels of both cobalt and chromium in whole blood and chromium in serum
|
| Follow-up Visits and Length of Follow-up |
Not applicable.
|
| Interim or Final Data Summary |
| Interim Results |
According to this 522 study results, device safety for the following Biomet Metal-on-Metal Hip Arthroplasty devices: M2a 38mm, M2a Magnum, M2a Ringloc, and M2a Taper, is consistent with the expected safety of MoM hip arthroplasty devices in general. No unexpected adverse events were identified in association the devices under review. However, some Musculoskeletal and Neurological AEs appeared to occur earlier in the MoM vs. MoP; the rate of Allergy/ Immunological AEs was higher in the MoM group.
Both Cr and Co levels were significantly associated with revision. The Implant type (MoM vs. MoP) was shown to affect the metal ion levels; the MoM (but not MoP) patients with an ALTR had higher metal ion levels. A number of variables (e.g., gender, bilateral status) were shown to correlate with metal ion levels. While no significant predictors were identified in the analysis based on a conventional threshold of >7 ppb, in the >2.5 ppb based regression model, “high” ion levels were predicted by the MoM implants, bilateral implants, younger age, longer post- implantation time (year since surgery), and occurrence of pain or functional symptoms. Although the latter analysis should be viewed as exploratory, these results suggest that lowering the currently accepted cut-off of 7ppb may benefit the risk assessment of possible metal debris related complications. In addition to the correlation between taper wear and development of pseudotumors, as identified in the Biomet explant analysis, the current clinical study emphasized the role of MRI in the assessment of pseudotumors. These findings are particularly important for the management of asymptomatic patients with MoM THR.
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| Actual Number of Patients Enrolled |
302 patients
|
| Actual Number of Sites Enrolled |
4 sites
|
| Final Safety Findings |
According to this 522 study results, device performance for the following Biomet Metal-on-Metal Hip Arthroplasty devices: M2a 38mm, M2a Magnum, M2a Ringloc, and M2a Taper, is consistent with that of MoM hip arthroplasty devices in general.
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| Study Strengths and Weaknesses |
Additional information on the role of metal ion levels that was derived from this study can help with optimizing management of patients with MoM THA arthroplasty. However, further studies are needed for addressing the remaining questions that were beyond the scope of the study, e.g., confirmation of metal reactivity in MoM THA associated adverse events as well as development of working recommendations for implementing clinically meaningful cut-off criteria for metal ion levels. Taken together with the results of corresponding Explant Analysis, the current study raises the need for consideration of the updated criteria for MoM THA related metal ion blood/serum measurements. As more meaningful metal ion related trends were identified when the threshold of 2.5 ppb (and not 7 ppb) was used, further studies are needed for exploring the utility of a lower threshold when interpreting the metal ion levels in clinical setting.
|
| Recommendations for Labeling Changes |
No labeling change is being recommended because Biomet
MoM THA devices are no longer marketed.
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