title: Biomechanical comparison of fixed- and mobile-bearing for unicomparmental knee arthroplasty using finite element analysis.
abstract: Unicomparmental knee arthroplasty (UKA) is a popular alternative to total knee arthroplasty (TKA) and high tibial osteotomy for unicompartmental knee conditions, especially in young patients. However, failure of UKA occurs due to either progressive osteoarthritis (OA) in the other compartment or wear on the polyethylene (PE) insert. This study used finite element (FE) analysis to investigate the effects of PE insert contact pressure and stress in opposite compartments for fixed- and mobile-bearing UKA. Analysis was performed using high kinematics displacement and rotation inputs, which were based on the kinematics of the natural knee. ISO standards were used for axial load and flexion. The mobile-bearing PE insert had lower contact pressure than the fixed-bearing PE insert. With the mobile-bearing UKA, lower stress on the opposite compartment reduces the overall risk of progressive OA in the knee. The fixed-bearing UKA increases the overall risk of progressive OA in the knee due to higher stress on the opposite compartment. However, the PE insert of mobile-bearing showed pronounced backside stress at the inferior surface.
authors.affiliation: Joint Reconstruction Center, Department of Orthopaedic Surgery, Yonsei Sarang Hospital, 478-3, Bangbae-dong, Seocho-gu, Seoul, Republic of Korea.
authors.forename: Oh-Ryong
authors.initials: OR
authors.lastname: Kwon
authors.forename: Kyoung-Tak
authors.initials: KT
authors.lastname: Kang
authors.forename: Juhyun
authors.initials: J
authors.lastname: Son
authors.forename: Sae-Kwang
authors.initials: SK
authors.lastname: Kwon
authors.forename: Seung-Bae
authors.initials: SB
authors.lastname: Jo
authors.forename: Dong-Suk
authors.initials: DS
authors.lastname: Suh
authors.forename: Yun-Jin
authors.initials: YJ
authors.lastname: Choi
authors.forename: Ho-Joong
authors.initials: HJ
authors.lastname: Kim
authors.forename: Yong-Gon
authors.initials: YG
authors.lastname: Koh
mesh_terms: D000328:Adult; D019645:Arthroplasty, Replacement, Knee; D001696:Biomechanical Phenomena; D020342:Finite Element Analysis; D006801:Humans; D007719:Knee Joint; D007720:Knee Prosthesis; D008297:Male; D008953:Models, Anatomic; D020370:Osteoarthritis, Knee; D020959:Polyethylene
chemical_list: D020959:Polyethylene
keywords: contact pressure; finite element analysis; osteoarthritis; polyethylene wear; unicomparmental knee arthroplasty