The purpose of this clinical study is to evaluate blood metal ion levels as a function of time of implantation for the ASR-XL MoM system.
Study Type
OBSERVATIONAL
Enrollment
146
All patients that are post-operative will have undergone total hip arthroplasty with the ASR-XL Metal-on-Metal device.
Unnamed facility
Fort Collins, Colorado, United States
Unnamed facility
Glenview, Illinois, United States
Unnamed facility
Rockford, Illinois, United States
Unnamed facility
Las Vegas, Nevada, United States
Change in Chromium serum ion level across time intervals
To compare the chromium serum ion levels in the patient population from pre-operatively through 6 years post-operatively in a 1-way ANOVA. This is a cross-sectional study so each time interval (2 through 6 years) will be a different cohort of patients. Notes: Pre-operative values are being collected via a separate protocol. There is no 1 year data available for this product due its withdrawal from the market.
Time frame: Pre-operatively through 6 years
Change in Chromium whole blood ion level across time intervals
To compare the chromium whole blood ion levels in the patient population from pre-operatively through 6 years post-operatively in a 1-way ANOVA. This is a cross-sectional study so each time interval (2 through 6 years) will be a different cohort of patients. Notes: Pre-operative values are being collected via a separate protocol. There is no 1 year data available for this product due its withdrawal from the market.
Time frame: Pre-operatively through 6 years
Change in Cobalt serum ion level across time intervals
To compare the cobalt serum ion levels in the patient population from pre-operatively through 6 years post-operatively in a 1-way ANOVA. This is a cross-sectional study so each time interval (2 through 6 years) will be a different cohort of patients. Notes: Pre-operative values are being collected via a separate protocol. There is no 1 year data available for this product due its withdrawal from the market.
Time frame: Pre-operatively through 6 years
Change in Cobalt whole blood ion level across time intervals
To compare the cobalt whole blood ion levels in the patient population from pre-operatively through 6 years post-operatively in a 1-way ANOVA. This is a cross-sectional study so each time interval (2 through 6 years) will be a different cohort of patients. Notes: Pre-operative values are being collected via a separate protocol. There is no 1 year data available for this product due its withdrawal from the market.
Time frame: Pre-operatively through 6 years
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Unnamed facility
Durham, North Carolina, United States
Unnamed facility
Cincinnatti, Ohio, United States
Unnamed facility
Austin, Texas, United States
Poolability of data across stem types
Within each of the primary analyses, the poolability of the data across stem types will be confirmed with a 2-way ANOVA model in which both time interval and stem type are independent variables. Note: Pre-operative data is being collected via a separate protocol.
Time frame: Pre-operatively through 6 years post-operatively
Incidence of adverse local tissue reaction (ALTR)
To determine trends in the incidence of ALTR over time.
Time frame: Pre-operatively through 6 years post-operatively
Implant survivorship
To determine implant survivorship, where an implant is considered to be surviving when none of the total hip replacement (THR)system components have been removed or replaced, so that the original system with metal-on-metal (MoM) articulating surfaces remains intact. Implant survivorship will be analyzed in two ways: 1) for all revisions (for any reason)and 2) for revisions due to ALTR.
Time frame: Through 6 years post-operatively
To identify the incidence of ALTR among unrevised subjects
To identify the incidence of ALTR among unrevised subjects through physical examination and imaging.
Time frame: Through 6 years post-operatively
Ion levels among revised subjects
To compare cobalt and chromium ion level (prior to revision) vs. baseline for subjects who are revised. Note: Pre-operative levels are being obtained via a separate protocol.
Time frame: Pre-operatively through 6 years post-operatively
Harris Hip and HOOS analysis for pain, function and total score
To identify the incidence of pain or functional symptoms among unrevised subjects with a Harris Hip and HOOS evaluation. To compare cobalt and chromium ion levels for unrevised subject who are exhibiting pain or functional symptoms vs. unrevised subject who are not exhibiting pain or functional symptoms.
Time frame: Through 6 years post-operatively
To determine the association of adverse events with elevated ion levels
To investigate the association of adverse events with elevated cobalt and chromium ion levels. For each respective adverse event, to compare cobalt and chromium ion levels for subjects who have vs. subjects who have not exhibited the adverse event. For each respective adverse event category, to present summary statistics of cobalt and chromium ion levels for subjects who have vs. subjects who have not exhibited the adverse event, stratified by post-op time cohort.
Time frame: Through 6 years post-operatively
Trending
Trends (over time since initial implant) will be evaluated for : 1) revisions (survivorship), 2) adverse events, 3) pain or functional symptoms (via Harris Hip and HOOS evaluations), 4) incidence of ALTR in unrevised subjects
Time frame: Through 6 years post-operatively
Patient history and demographics and association with outcomes
Patient demographic and subject history will be evaluated for association with: 1) higher metal ion levels and 2) risk of revision
Time frame: Throughout 6 years post-operatively
Modes and causes of implant failure
To evaluate modes and causes of implant failure based on an analysis of reasonably available explanted retrieved devices.
Time frame: Through 6 years post-operatively
Metal ion levels and association with reason for revision
To compare cobalt and chromium levels across the different reasons for revision.
Time frame: Through 6 years post-operatively
Comparison of metal ion levels across subjects with vs. without ALTR
Cobalt and chromium ion levels will be compared for unrevised subjects who were not diagnosed with an ALTR vs. unrevised subjects who were diagnosed with an ALTR.
Time frame: Through 6 years post-operatively
Ion level vs. baseline for ALTR subjects
To compare cobalt and chromium ion level vs. baseline for subjects who are diagnosed with ALTR. Note: Baseline measurements are being captured via a separate protocol.
Time frame: Through 6 years post-operatively
Ion level change from first measurement for ALTR subjects
Cobalt and chromium ion levels will be compared from first measurement to the time of revision (prior to revision) or the time of last follow-up visit in the study, whichever comes first, for subjects who are diagnosed with an ALTR.
Time frame: Through 6 years post-operatively