title: Femoral condylar contact points start and remain posterior in high flexing patients.
abstract: This study compares kinematic patterns of 136 patients following total knee arthroplasty with high post-operative knee flexion (HighFlex) versus kinematics of 114 patients with limited knee flexion (LowFlex) using a blocked stratified random sampling study design to reduce confounding and bias. The kinematics was collected using fluoroscopy and 2D to 3D registration for a weight-bearing deep knee bend activity. Both the lateral and the medial condylar contact positions for the HighFlex subjects were significantly more posterior than the LowFlex subjects at full extension and remained that way at all flexion angles. The amount translation of the contact points, axial orientation angle and axial rotation were found to be similar for the two groups. Lift-off was significantly higher in the LowFlex indicating mid-flexion instability.
authors.affiliation: Center for Musculoskeletal Research, University of Tennessee, Knoxville, Tennessee.
authors.forename: Adrija
authors.initials: A
authors.lastname: Sharma
authors.affiliation: Department of Biomedical Engineering, University of Tennessee, Knoxville, Tennessee; Department of Orthopedics, University of Colorado School of Medicine, Denver, Colorado; University of Denver, Denver, Colorado.
authors.forename: Douglas A
authors.initials: DA
authors.lastname: Dennis
authors.affiliation: Center for Musculoskeletal Research, University of Tennessee, Knoxville, Tennessee.
authors.forename: Sumesh M
authors.initials: SM
authors.lastname: Zingde
authors.affiliation: Center for Musculoskeletal Research, University of Tennessee, Knoxville, Tennessee.
authors.forename: Mohamed R
authors.initials: MR
authors.lastname: Mahfouz
authors.affiliation: Center for Musculoskeletal Research, University of Tennessee, Knoxville, Tennessee.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Komistek
mesh_terms: D019645:Arthroplasty, Replacement, Knee; D001696:Biomechanical Phenomena; D005269:Femur / Q000503:physiopathology / Q000601:surgery*; D005471:Fluoroscopy; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology* / Q000601:surgery; D016059:Range of Motion, Articular
keywords: fluoroscopy; kinematics; multicenter; randomized; total knee arthroplasty