A Prospective RSA and Clinical Evaluation of the Trident II Acetabular Cup

Study Overview
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Brief Summary
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The objective of this study is to use radiostereometric analysis (RSA) and clinical outcome measures to evaluate early post-operative implant stability and the clinical performance of Stryker's Trident II Acetabular Cup.

Detailed Description
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The proposed study is a prospective evaluation of data from patients undergoing primary total hip arthroplasty using the Trident II acetabular cup. Fifty patients will be recruited for this study. All patients that qualify for the study per the inclusion-exclusion criteria and provide written informed consent will receive the Trident II acetabular cup and RSA beads. Implant stability, through RSA, will be measured throughout the first two postoperative (post-op) years per the following schedule: immediate post-op and 6 weeks, 3 months, 6 months, 1 year, and 2 years following surgery. Patients will be discharged and seen for follow-up assessments as per standard of care. Adverse events that are related to the index joint will be collected. Health outcome questionnaires will be collected. The health outcome questionnaires will include: EQ-5D, HOOS JR and Harris Hip Score. Health outcome questionnaires will be completed pre-operatively and again at 6 weeks, 3 months, 6 months, 1 year and 2 years following surgery. Conventional x-ray analysis will be performed pre-operatively and again at 6 weeks, 1 year and 2 years following surgery.

Official Title
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A Prospective RSA and Clinical Evaluation of the Trident II Acetabular Cup

Conditions
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Acetabular Cup, Total Hip Arthroplasty

Intervention / Treatment
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* Radiation: Radiostereometric Analysis
* Procedure: total hip arthroplasty with RSA bead implantation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Symptomatic arthritis of the hip indicating surgical intervention Scheduled to undergo a primary total hip arthroplasty Patient is a candidate for the Trident II acetabular cup in accordance with product labeling - Exclusion Criteria: Patients less than 18 years of age, or older than 85 years of age. Severe hip dysplasia (Crowe Type III or IV) in the affected hip History of congenital dislocation Prior arthroplasty of the affected hip Active or prior infection of the affected hip Morbid obesity (BMI > 40) Medical condition precluding major surgery Severe osteoporosis Neuromuscular impairment Patients with known allergy to metals Pregnancy Patients on dialysis or creatinine > 2.0 Patient is immuno-suppressed -

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 85 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Trident II acetabular cup<br>Subjects receive the Trident II acetabular cup and RSA beads and undergo a series of post-operative RSA exams. | Radiation: Radiostereometric Analysis<br>* RSA exams of the operative hip are received post-op day 1, and at 6 weeks, 3 months, 6 months, 1 year and 2 years following surgery<br>Procedure: total hip arthroplasty with RSA bead implantation<br>* Patients receive RSA beads inserted into the bone surrounding the Trident II implant.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Does the Trident II Cup achieve acceptable fixation to the underlying bone? | The Trident II Cup proximal migration will be assessed. Migration of less than 0.2mm at 2 years and without continuous migration between post-operative year 1 and 2 will indicate acceptable fixation. | 3 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| What are the migration patterns of the Trident II acetabular cup over the first two post-operative years? | Migration patterns will be assessed using RSA analysis. | 3 years | 
| Is there a significant difference in health status and functional outcome before and after hip arthroplasty using Trident II Cup? | The health status and functional outcome will be assessed via Harris Hip Score. | 3 years | 
| Is there a significant difference in health status and functional outcome before and after hip arthroplasty using Trident II Cup? | The health status and functional outcome will be assessed via EQ-5D. | 3 years | 
| Is there a correlation between radiolucent lines measured by Charnley-DeLee zone analysis and migration characteristics using RSA? | X-ray radiographs will be taken at pre-op, 6 weeks, 1 year and 2 year appointments. It may take up to 3 years after study start for all patients to reach the 2 year visit mark, depending on how long enrollment takes. | 3 years | 
| Can inducible displacements measured at 1 year post-operative distinguish patients identified by RSA measurements as having inadequate fixation? | Inducible displacements will be measured using RSA exams at the 1 year follow-up. It may take up to 2 years after study start for all patients to reach the 1 year visit mark, depending on how long enrollment takes. | 2 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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RSA, THA, Trident