title: Simulated normal gait wear testing of a highly cross-linked polyethylene tibial insert.
abstract: Polyethylene wear can compromise long-term performance of total knees. We investigated articular and backside wear rate of tibial inserts made from conventional vs highly cross-linked polyethylenes. The inserts were tested on a knee simulator at a frequency of 1.1 Hz using normal gait kinematics with a 7 degrees posterior slope for 7 million cycles. Gravimetrically, the combined articular and backside wear rate was 23 +/- 6 and 4.6 +/- 2 mm(3) per million cycles for the conventional and cross-linked inserts, respectively. We independently measured articular surface wear rates, which were 15 +/- 4 and 5 +/- 2 mm(3) per million cycles for conventional and cross-linked inserts, respectively. Electron beam cross-linked and subsequently melted polyethylene reduced the wear rate of polyethylene on articular and backside surfaces in a cruciate-retaining total knee design when tested on a knee simulator under simulated normal gait.
authors.affiliation: Orthopaedic Biomechanics and Biomaterials Laboratory, Massachusetts General Hospital, Boston, Massachussetts.
authors.forename: Orhun K
authors.initials: OK
authors.lastname: Muratoglu
authors.forename: Harry E
authors.initials: HE
authors.lastname: Rubash
authors.forename: Charles R
authors.initials: CR
authors.lastname: Bragdon
authors.forename: Brian R
authors.initials: BR
authors.lastname: Burroughs
authors.forename: Anna
authors.initials: A
authors.lastname: Huang
authors.forename: William H
authors.initials: WH
authors.lastname: Harris
mesh_terms: D005269:Femur / Q000502:physiology; D005684:Gait; D006801:Humans; D007720:Knee Prosthesis; D008422:Materials Testing; D020959:Polyethylene; D011474:Prosthesis Design; D012399:Rotation
chemical_list: D020959:Polyethylene