In Vivo Kinematics Comparison of Stryker or Zimmer Total Knee Arthroplasty

Study Overview
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Brief Summary
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This study will compare the kinematics data collected from patients with implants created by different manufacturers to see which of these implants provides a more normal-like kinematic pattern compared to the normal knee.

Detailed Description
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A better understanding of knee joint kinematics is important to explain premature polyethylene wear failures within knee implants and to help design a prosthesis that most closely approximates the normal knee. Therefore, the objectives for this study are to compare the in vivo kinematic patterns for subjects implanted with either a Stryker Triathlon Posterior Cruciate Retaining (PCR) Total Knee Arthroplasty (TKA) or Zimmer NexGen PCR TKA design to determine if there are any kinematic differences between these TKA designs. Each subject will be asked to undergo a fluoroscopic evaluation while performing weight-bearing activities under surveillance using the University of Tennessee's new mobile tracking fluoroscopic unit while performing deep knee bend and ramp up and ramp down activities. The mobile fluoroscopy unit is approved for use by the State of Tennessee on a study-by-study basis after IRB approval is obtained for each study.

Official Title
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In Vivo Comparison of Kinematics for Patients Implanted With Either a Stryker or a Zimmer Posterior Cruciate Retaining Total Knee Arthroplasty

Conditions
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Knee Prosthesis

Intervention / Treatment
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* Device: Stryker posterior cruciat retaining (PCR) total knee arthroplasty (TKA)
* Device: Zimmer PCR TKA


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Must be at least 3 months post-operative with no other surgical procedures conducted within the past 6 months Must have body weight of less than 250 lbs Must have Body Mass Index of less than 38 Must be judged clinically successful with a Knee Society Score >90 Must have 100% post-operative passive flexion with no ligamentous laxity or pain Must be able to walk on level ground without aid of any kind Must be able to ascend and descend a ramp with a 10 degree incline with no assistance Must be willing to sign both Informed Consent and HIPAA forms Must be between 160 cm (5'3) and 193 cm (6'4) tall Exclusion Criteria: Pregnant or potentially pregnant females Unwilling to sign Informed Consent or HIPAA forms

Ages Eligible for Study
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Minimum Age: 40 Years
Maximum Age: 70 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Patients with a Stryker Triathlon CR TKA<br>Patients implanted with a Stryker Triathlon Posterior Cruciate Retaining Total Knee Arthroplasty. | Device: Stryker posterior cruciat retaining (PCR) total knee arthroplasty (TKA)<br>* The fluoroscopy procedure itself is used as a means of data collection and is not the intervention under investigation; therefore, the study is observational and not interventional.<br>* Other names: Triathlon PCR TKA;|
| Patients with a Zimmer PCR TKA<br>Patients implanted with a Zimmer NexGen Posterior Cruciate Retaining Total Knee Arthroplasty. | Device: Zimmer PCR TKA<br>* The fluoroscopy procedure itself is used as a means of data collection and is not the intervention under investigation; therefore, the study is observational and not interventional.<br>* Other names: Zimmer NexGen PCR TKA;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Kinematics - Deep Knee Bend Activity | Lateral Anterior Posterior (LAP) and Medial Anterior Posterior (MAP) translations, and Axial Rotation (AR) and maximum flexion of medial femoral condyles during deep knee bend (DKB) activity | 3 months post-operative | 
| Kinematics - Ramp up Activity | Lateral Anterior Posterior (LAP) [during 3 moments - 0-33%, 33-66% and 66-100%] and Medial Anterior Posterior (MAP) [during 3 moments - 0-33%, 33-66% and 66-100%] translations, and Axial Rotation (AR) [during 3 moments - 0-33%, 33-66% and 66-100%] of medial femoral condyles during ramp up activity | 3 months post-operative | 
| Kinematics - Ramp Down Activity | Lateral Anterior Posterior (LAP) [during 3 moments - 0-33%, 33-66% and 66-100%] and Medial Anterior Posterior (MAP) [during 3 moments - 0-33%, 33-66% and 66-100%] translations, and Axial Rotation (AR) [during 3 moments - 0-33%, 33-66% and 66-100%] of medial femoral condyles during ramp down activity | 3 months post-operative | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Knee Prosthesis, Total Knee Arthroplasty, Cruciate Retaining, Posterior Cruciate Retaining