title: Multiobjective optimization of cartilage stress for non-invasive, patient-specific recommendations of high tibial osteotomy correction angle - a novel method to investigate alignment correction.
abstract: Medial opening wedge high tibial osteotomy (MOWHTO) is a surgical procedure to treat knee osteoarthritis associated with varus deformity. However, the ideal final alignment of the Hip-Knee-Ankle (HKA) angle in the frontal plane, that maximizes procedural success and post-operative knee function, remains controversial. Therefore, the purpose of this study was to introduce a subject-specific modeling procedure in determining the biomechanical effects of MOWHTO alignment on tibiofemoral cartilage stress distribution. A 3D finite element knee model derived from magnetic resonance imaging of a healthy participant was manipulated in-silico to simulate a range of final HKA angles (i.e. 0.2°, 2.7°, 3.9° and 6.6° valgus). Loading and boundary conditions were assigned based on subject-specific kinematic and kinetic data from gait analysis. Multiobjective optimization was used to identify the final alignment that balanced compressive and shear forces between medial and lateral knee compartments. Peak stresses decreased in the medial and increased in the lateral compartment as the HKA was shifted into valgus, with balanced loading occurring at angles of 4.3° and 2.9° valgus for the femoral and tibial cartilage respectively. The concept introduced here provides a platform for non-invasive, patient-specific preoperative planning of the osteotomy for medial compartment knee osteoarthritis.
authors.affiliation: School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006, Australia; Sydney Orthopaedic Research Institute, Chatswood, NSW 2067, Australia.
authors.forename: Keke
authors.initials: K
authors.lastname: Zheng
authors.affiliation: Sydney Orthopaedic Research Institute, Chatswood, NSW 2067, Australia.
authors.forename: Corey J
authors.initials: CJ
authors.lastname: Scholes
authors.affiliation: School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006, Australia.
authors.forename: Junning
authors.initials: J
authors.lastname: Chen
authors.affiliation: Sydney Orthopaedic Research Institute, Chatswood, NSW 2067, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Parker
authors.affiliation: School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006, Australia. Electronic address: qing.li@sydney.edu.au.
authors.forename: Qing
authors.initials: Q
authors.lastname: Li
mesh_terms: D000328:Adult; D002358:Cartilage, Articular; D019245:Compressive Strength; D006801:Humans; D008297:Male; D010027:Osteotomy; D057285:Precision Medicine; D013314:Stress, Mechanical; D013977:Tibia / Q000601:surgery*
keywords: High tibial osteotomy; Hyperelastic model; Non-linear FEA; Optimization; Patient-specific