Metal on Metal Versus Metal on Highly Crossed Linked Polyethylene Sytem

Study Overview
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Brief Summary
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This trial will evaluate the 36mm or greater metal head on metal hip system and compare it to the 32mm or 28mm metal head on polyethylene (liner) hip system in patients receiving a primary cementless total hip replacement.

Official Title
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A Randomized Multicentre Clinical Trial Comparing The Metal on Metal Hip System Versus The Metal on Highly Crossed Linked Polyethylene System

Conditions
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Osteoarthritis, Avascular Necrosis, Rheumatoid Arthritis, Congenital Dysplasia of the Hip, Ankylosing Spondylitis, Post-traumatic; Arthrosis, Injury of Hip and Thigh

Intervention / Treatment
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* Device: Metal on Metal Hip System
* Device: Highly Cross Linked Polyethylene cup System


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male and non-pregnant female subjects 65 years of age or older Subjects undergoing cementless hip arthroplasty. If a press fit metal articulation acetabulum is not possible; the modular cup system will be utilized with screw fixation and a metal head of the greatest diameter deemed appropriate and safe for the patient will be utilized.(At the discretion of the surgeon). The cup in this situation may have a metal or poly articulation. The patient will be followed as an intent to treat (the patient will be evaluated and included in the group as randomized) Subjects with, but not limited to, original diagnoses of osteoarthritis, avascular necrosis, rheumatoid arthritis, congenital dysplasia of the hip, ankylosing spondylitis, posttraumatic arthritis, and traumatic injury to the hip joint. Subjects who are able and willing to understand the conditions of informed consent, to participate in the study according to the protocol for the length of the expected term of follow-up, and to follow their physician's directions. Exclusion Criteria: Subjects undergoing hip arthroplasty using a cemented femoral component and/or a bipolar prosthesis. Subjects with gross obesity, >45% over ideal body weight for age and height. Refer to Appendix A, Obesity Table. Subjects with active infections. Subjects with malignancy in the area of the involved hip joint. Subjects with a neuromuscular deficit that interferes with the subject's ability to limit weight bearing or places an extreme load on the implant during the healing period. Subjects with a diagnosis of Fibromyalgia Female subjects who are pregnant or may be pregnant. Subjects whom, as judged by the surgeon, are not capable of understanding the informed consent or the requirements of the protocol, or are reasonably unlikely to be compliant with the prescribed postoperative routine and the follow-up evaluation schedule. Subjects who have a known sensitivity to device materials.

Ages Eligible for Study
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Minimum Age: 65 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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Metal on Metal<br>Metal on Metal articulation system | Device: Metal on Metal Hip System<br>* Total hip arthroplasty with a metal on metal component system<br>* Other names: Depuy ASR;|
| Active Comparator: HCLPC<br>THA using Highly Cross Linked Polyethylene cup System | Device: Highly Cross Linked Polyethylene cup System<br>* Total hip arthroplasty with Highly Cross Linked Polyethylene cup System<br>* Other names: Depuy Pinnacle Cup and Marathon liner;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Revision Rate |  | 4 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Wear and osteolysis |  | 5-15 years | 
| Harris Hip Score |  | immediate post-op, 6 months, 1 year, 2 years, 4 years | 
| Dislocation Rate |  | 4 years | 
| Complication Rate | All complications | 4 years | 
| Gait Analysis | Using the Walkabout portable gait monitor | 6 months and 1 year post-op | 
| Metal Ions |  | 4 years |