title: The effect of rotating platform TKA on strain distribution and torque transmission on the proximal tibia.
abstract: Limited experimental data exist comparing the mechanical response of the tibial cortex between fixed and rotating platform (RP) total knee arthroplasty (TKA), particularly in the revision setting. We asked if RP-TKA significantly affects tibiofemoral torque and cortical stain response in both the primary and revision settings. Fixed and RP tibial trays were implanted into analogue tibias and biomechanically tested under axial and torsional loading. Torque and strain response were analyzed using digital image correlation. Fixed bearing designs exhibited 13.8 times greater torque (P<0.01), and 69% (P<0.01) higher cortical strain than RP designs. Strain response was similar in the primary and revision cohorts. The decrease in torque transfer could act as a safeguard to reduce stress, micromotion and torsional fatigue in scenario of poor bone stock.
authors.affiliation: Joint Replacement Surgeons of Indiana Foundation, Inc., Mooresville, Indiana.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Malinzak
authors.affiliation: Joint Replacement Surgeons of Indiana Foundation, Inc., Mooresville, Indiana.
authors.forename: Scott R
authors.initials: SR
authors.lastname: Small
authors.affiliation: Department of Applied Biology and Biomedical Engineering, Rose-Hulman Institute of Technology, Terre Haute, Indiana.
authors.forename: Renee D
authors.initials: RD
authors.lastname: Rogge
authors.affiliation: Department of Applied Biology and Biomedical Engineering, Rose-Hulman Institute of Technology, Terre Haute, Indiana.
authors.forename: Derek B
authors.initials: DB
authors.lastname: Archer
authors.affiliation: Department of Applied Biology and Biomedical Engineering, Rose-Hulman Institute of Technology, Terre Haute, Indiana.
authors.forename: Jordan W
authors.initials: JW
authors.lastname: Oja
authors.affiliation: Joint Replacement Surgeons of Indiana Foundation, Inc., Mooresville, Indiana.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Berend
authors.affiliation: Joint Replacement Surgeons of Indiana Foundation, Inc., Mooresville, Indiana.
authors.forename: Merrill A
authors.initials: MA
authors.lastname: Ritter
mesh_terms: D019645:Arthroplasty, Replacement, Knee; D001696:Biomechanical Phenomena; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology* / Q000601:surgery; D007720:Knee Prosthesis; D008962:Models, Theoretical; D011474:Prosthesis Design; D012086:Reoperation; D013314:Stress, Mechanical; D013977:Tibia / Q000503:physiopathology* / Q000601:surgery; D019415:Torque
keywords: TKA; digital image correlation; mobile bearing; rotating platform; strain; torque