Comparison of Knee Kinematics for Subjects Implanted With Either a ConforMIS or Traditional Knee Implant
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. Previously, most experimental studies of knee kinematics have involved cadaveric, in vitro analyses, or have not tested the knee in a weight-bearing mode. Others have used exoskeletal linkages and skin markers that permit error due to undesired motions between markers and the underlying bone. More recently, fluoroscopy has been used to assess in vivo kinematics for subjects having a TKA.
ConforMIS has attempted to follow a clearly different path than the major orthopaedic companies. They have chosen to offer patients a personalized knee implant based off of each patient's femoral and tibial bone geometry. The hypothesis is that these subjects will experience a more normal-like kinematic pattern, eliminating paradoxical anterior sliding during weight-bearing knee flexion. Therefore, the objective for this study is to analyze the in vivo kinematics for 25 patients implanted with a personalized ConforMIS TKA and 25 patients implanted with a traditional TKA design to determine if there are any kinematic differences between these TKA designs.
Total Knee Arthroplasties
|Study Design:||Observational Model: Case Control
Time Perspective: Prospective
|Official Title:||In Vivo Determination & Comparison of Knee Kinematics for Subjects Implanted With Either a Personalized ConforMIS or Traditional Knee Implant|
- Patients with ConforMIS implant will experience more normal like kinematic pattern [ Time Frame: at least 6 months post surgery ] [ Designated as safety issue: No ]
|Study Start Date:||August 2012|
|Estimated Study Completion Date:||August 2014|
|Estimated Primary Completion Date:||June 2014 (Final data collection date for primary outcome measure)|
Patients with ConforMIS implants
Standard Total Knee Implant
Patients implanted with standard total knee implant
Each subject will be asked to perform five activities in one continuous sequence: (1) stand up from a chair, (2) walk up stairs, (3) walk down stairs, (4) level walking, and (5) a deep knee bend. Subjects will be video recorded from the waist down while performing the activities. The speed level of each trial will be based on the comfort level of the patient. The fluoroscopic images will be stored digitally for subsequent analysis on secure servers and workstations at the University of Tennessee.
|United States, Tennessee|
|University of Tennessee|
|Knoxville, Tennessee, United States, 37996|
|Tennessee Orthopedic Alliance|
|Nashville, Tennessee, United States, 37203|
|Principal Investigator:||Richard D Komistek, PhD||Univeristy of Tennessee|
|Principal Investigator:||William Kurtz, MD||Tennessee Orthopedic Alliance|