title: Dynamic contact mechanics on the tibial plateau of the human knee during activities of daily living.
abstract: Despite significant advances in scaffold design, manufacture, and development, it remains unclear what forces these scaffolds must withstand when implanted into the heavily loaded environment of the knee joint. The objective of this study was to fully quantify the dynamic contact mechanics across the tibial plateau of the human knee joint during gait and stair climbing. Our model consisted of a modified Stanmore knee simulator (to apply multi-directional dynamic forces), a two-camera motion capture system (to record joint kinematics), an electronic sensor (to record contact stresses on the tibial plateau), and a suite of post-processing algorithms. During gait, peak contact stresses on the medial plateau occurred in areas of cartilage-cartilage contact; while during stair climb, peak contact stresses were located in the posterior aspect of the plateau, under the meniscus. On the lateral plateau, during gait and in early stair-climb, peak contact stresses occurred under the meniscus, while in late stair-climb, peak contact stresses were experienced in the zone of cartilage-cartilage contact. At 45% of the gait cycle, and 20% and 48% of the stair-climb cycle, peak stresses were simultaneously experienced on both the medial and lateral compartment, suggesting that these phases of loading warrant particular consideration in any simulation intended to evaluate scaffold performance. Our study suggests that in order to design a scaffold capable of restoring 'normal' contact mechanics to the injured knees, the mechanics of the intended site of implantation should be taken into account in any pre-clinical testing regime.
authors.affiliation: Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021, United States.
authors.forename: Susannah
authors.initials: S
authors.lastname: Gilbert
authors.affiliation: Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021, United States.
authors.forename: Tony
authors.initials: T
authors.lastname: Chen
authors.affiliation: Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021, United States.
authors.forename: Ian D
authors.initials: ID
authors.lastname: Hutchinson
authors.affiliation: Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021, United States.
authors.forename: Dan
authors.initials: D
authors.lastname: Choi
authors.affiliation: Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021, United States.
authors.forename: Clifford
authors.initials: C
authors.lastname: Voigt
authors.affiliation: Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021, United States.
authors.forename: Russell F
authors.initials: RF
authors.lastname: Warren
authors.affiliation: Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021, United States. Electronic address: mahers@hss.edu.
authors.forename: Suzanne A
authors.initials: SA
authors.lastname: Maher
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D001696:Biomechanical Phenomena; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D007719:Knee Joint / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D013977:Tibia / Q000502:physiology*
keywords: Functional scaffolds; Gait; Knee contact mechanics; Stair-climb