In Vivo Kinematics Comparison of Stryker or Zimmer Total Knee Arthroplasty

Completed

Interventions: Device: Stryker posterior cruciat retaining (PCR) total knee arthroplasty (TKA)
Device: Zimmer PCR TKA

Brief Summary: 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: 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.

Recruitment & Eligibility

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

Arm && Interventions

Group	Intervention	Description
Patients with a Stryker Triathlon CR TKA	Stryker posterior cruciat retaining (PCR) total knee arthroplasty (TKA)	Patients implanted with a Stryker Triathlon Posterior Cruciate Retaining Total Knee Arthroplasty.
Patients with a Zimmer PCR TKA	Zimmer PCR TKA	Patients implanted with a Zimmer NexGen Posterior Cruciate Retaining Total Knee Arthroplasty.

Primary Outcome Measures

Name	Time	Method
Kinematics - Ramp up Activity	3 months post-operative	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
Kinematics - Deep Knee Bend Activity	3 months post-operative	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
Kinematics - Ramp Down Activity	3 months post-operative	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

Secondary Outcome Measures

Name	Time	Method

Locations (4): Dougherty Engineering Building, Room M007
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Knoxville, Tennessee, United States
Perkins Hall, The University of Tennessee
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Knoxville, Tennessee, United States
Science and Engineering Research Facility
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Knoxville, Tennessee, United States
Tennessee Orthopaedic Clinic, Tennessee Orthopaedic Foundation for Education & Research
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Knoxville, Tennessee, United States