Kinematic Analysis: Posterior Stabilized, Fixed Bearing Total Knee Arthroplasty With Attune Knee System - Phase 2

Study Overview
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Brief Summary
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A better understanding of knee joint kinematics is important to explain the premature polyethylene wear failures within total knee arthroplasties (TKAs) and to help design a prosthesis that most closely approximates the normal knee. Specifically, posterior stabilizing (PS) knees have been found to be associated with lower amounts of posterior femoral rollback, higher occurrence of reverse axial rotation and increased amount of condylar lift-off. The DePuy Synthes Joint Reconstruction's Attune PS fixed bearing (FB) knee system has incorporated subtle changes in its design to address restoration of kinematics that more closely resemble those of a normal knee. To understand if this design is able to effectively restore kinematics in the implanted knee, further in vivo analysis is necessary. This continuation of the study will analyze 30 subjects with the Attune PS FB 3 months post-operatively using the University of Tennessee's mobile fluoroscopy unit while performing three daily activities, level walking, ramp down and deep knee bend.

Official Title
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Kinematic Analysis: Posterior Stabilized, Fixed Bearing Total Knee Arthroplasty With Attune Knee System - Phase 2

Conditions
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Total Knee Arthroplasty, Osteoarthritis

Intervention / Treatment
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* Device: DePuy Attune posterior stabilizing fixed bearing knee system


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: At least three (3) months post-operative with no other surgical procedures conducted within the past six months Between 30-80 years of age Body weight of less than 280 lbs Must be between 160cm (5'3) and 193cm (6'4) tall Body Mass Index (BMI) >18.5 and <35 Judged clinically successful with a Knee Society score (KSS) of greater than 80 Have good-to-excellent post-operative passive flexion with no ligamentous laxity or pain Must be able to walk on level ground without aid of any kind, perform a ramp descent, and a deep knee bend (DKB), all without assistance Will have a DePuy Attune PS TKA Exclusion Criteria: Pregnant or potentially pregnant females will be excluded from the study.

Ages Eligible for Study
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Minimum Age: 30 Years
Maximum Age: 80 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 |
| --- | --- |
| DePuy Attune PS FB knee system<br>Patients implanted with a DePuy Attune posterior stabilizing fixed bearing knee system | Device: DePuy Attune posterior stabilizing fixed bearing knee system<br>* Individuals implanted with the DePuy Attune posterior stabilizing fixed bearing knee system at least three months post-operative.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Femoro-tibial Kinematics - Lateral Anterior/Posterior Motion | Amount of anterior sliding (positive) and/or posterior rollback (negative) of the lateral condyle during DKB, gait, and ramp down | 3 months post-operative | 
| Femoro-tibial Kinematics - Medial Anterior/Posterior Motion | Amount of anterior sliding (positive) and/or posterior rollback (negative) of the medial condyle during DKB, gait, and ramp down | 3 months post-operative | 
| Femoro-tibial Kinematics - Axial Rotation | Amount of axial rotation of the femoral component with respect to the tibial component during DKB, gait, and ramp down. Positive indicated external rotation of femur wrt tibia. | 3 months post-operative | 
| Femoro-tibial Kinematics - Weight-bearing Flexion | Amount of weight-bearing flexion during DKB, gait, and ramp down. All numbers are positive, indicating magnitude. | 3 months post-operative | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Max Ground Reaction Force - Deep Knee Bend | Collected simultaneously with fluoroscopy data, ground reaction forces were obtained using a force plate (fixed to the ground) while subject performed activity. Maximum force measured in the vertical direction measured during the activity was normalized with respect to participant's body weight and has been termed maximum reaction force. | 3 months post-operative | 
| Max Ground Reaction Force - Gait | Collected simultaneously with fluoroscopy data, ground reaction forces were obtained using a force plate (fixed to the ground) while subject performed activity. Maximum force measured in the vertical direction measured during the activity. was normalized with respect to participant's body weight and has been termed maximum reaction force. | 3 months post-operative | 
| Max Ground Reaction Force - Ramp Down | Collected simultaneously with fluoroscopy data, ground reaction forces were obtained using a force plate (fixed to the ground) while subject performed activity. Maximum force measured in the vertical direction measured during the activity. was normalized with respect to participant's body weight and has been termed maximum reaction force. | 3 months post-operative |