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

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 pilot study will analyze 5 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. Since this is a pilot study, there is no hypothesis.

Official Title
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Kinematic Analysis: Posterior Stabilized, Fixed Bearing Total Knee Arthroplasty

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 Must be willing to sign the Informed Consent (IC) and HIPAA forms to participate in the study 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 TKA<br>Individuals implanted with the DePuy Attune posterior stabilizing fixed bearing knee system implanted by a single surgeon at least three months post-operative. | Device: DePuy Attune posterior stabilizing fixed bearing knee system<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Femoro-tibial Kinematics - Translation and Lift-off for Deep Knee Bend | Amount of translation and lift-off for implanted knee in vivo under fluoroscopic surveillance during deep knee bend activity. | 3 months post-operative | 
| Femoro-tibial Kinematics: Translation and Lift-off for Gait | Amount of translation and lift-off for implanted knee in vivo under fluoroscopic surveillance during gait activity. | 3 months post-operative | 
| Femoro-tibial Kinematics: Translation and Lift-off for Ramp Down | Amount of translation and lift-off for implanted knee in vivo under fluoroscopic surveillance during ramp down activity. | 3 months post-operative | 
| Femoro-tibial Kinematics - Deep Knee Bend | Degree of axial rotation and weight-bearing range-of-motion for implanted knee in vivo under fluoroscopic surveillance during deep knee bend activity. | 3 months post-operative | 
| Femoro-tibial Kinematics - Gait | Degree of axial rotation and weight-bearing range-of-motion for implanted knee in vivo under fluoroscopic surveillance during gait activity. | 3 months post-operative | 
| Femoro-tibial Kinematics - Ramp Down | Degree of axial rotation and maximum weight-bearing range-of-motion for implanted knee in vivo under fluoroscopic surveillance during ramp down activity. | 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 described activity, then normalized with respect to participant's body weight. As such, the data are presented as the percentage of the individuals' body weight that was supported on the implanted knee using a force plate (fixed to the ground) 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 described activity, then normalized with respect to participant's body weight. As such, the data are presented as the percentage of the individuals' body weight that was supported on the implanted knee using a force plate (fixed to the ground) 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 described activity was normalized with respect to participant's body weight. As such, the data are presented as the percentage of the individuals' body weight that was supported on the implanted knee using a force plate (fixed to the ground) and has been termed maximum reaction force. | 3 months post-operative |