title: The biomechanical effect of increased valgus on total knee arthroplasty: a cadaveric study.
abstract: The effects of valgus load on cadaveric knees following total knee arthroplasty (TKA) were investigated using a custom testing system. TKAs were performed on 8 cadaveric knees and tested at 0°, 30°, and 60° knee flexion in both neutral and 5° valgus. Fuji pressure sensitive film was used to quantify contact areas and pressures and MCL strain was determined using a Microscribe digitizing system. Lateral tibiofemoral pressures increased (P < 0.05) at all knee flexion angles with valgus loading. Patellofemoral contact characteristics did not change significantly (P > 0.05). Significant increases in strain were observed along the anterior and posterior border of the MCL at all knee flexion angles. These findings suggest that valgus loading increases TKA joint contact pressures and MCL strain with increasing knee flexion which may increase implant instability.
authors.affiliation: Orthopaedic Biomechanics Laboratory VA Long Beach Healthcare System, California; University of California, Irvine.
authors.forename: Brandon J
authors.initials: BJ
authors.lastname: Bryant
authors.affiliation: Orthopaedic Biomechanics Laboratory VA Long Beach Healthcare System, California; University of California, Irvine.
authors.forename: Justin U
authors.initials: JU
authors.lastname: Tilan
authors.affiliation: Orthopaedic Biomechanics Laboratory VA Long Beach Healthcare System, California; University of California, Irvine.
authors.forename: Michelle H
authors.initials: MH
authors.lastname: McGarry
authors.affiliation: Orthopaedic Biomechanics Laboratory VA Long Beach Healthcare System, California; University of California, Irvine.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Takenaka
authors.affiliation: Orthopaedic Biomechanics Laboratory VA Long Beach Healthcare System, California; University of California, Irvine.
authors.forename: William C
authors.initials: WC
authors.lastname: Kim
authors.affiliation: Orthopaedic Biomechanics Laboratory VA Long Beach Healthcare System, California; University of California, Irvine.
authors.forename: Thay Q
authors.initials: TQ
authors.lastname: Lee
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee; D001696:Biomechanical Phenomena; D060751:Bone Retroversion / Q000503:physiopathology*; D002102:Cadaver; D005269:Femur / Q000503:physiopathology; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology* / Q000601:surgery; D017888:Medial Collateral Ligament, Knee / Q000503:physiopathology*; D057071:Patellofemoral Joint / Q000503:physiopathology; D016059:Range of Motion, Articular; D013314:Stress, Mechanical; D013977:Tibia / Q000503:physiopathology
keywords: MCL strain; patellofemoral contact; tibiofemoral contact; total knee arthroplasty; valgus