Biomechanical assessment for kinematical alignment TKA

• Project/Area Number: 18K16624
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 56020:Orthopedics-related
• Research Institution: Kobe University
• Principal Investigator: Takayama Koji 神戸大学, 医学研究科, 医学研究員 (80546490)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Project Status: Completed (Fiscal Year 2021)
• Budget Amount: ¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000); Fiscal Year 2021: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2020: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2019: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2018: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
• Keywords: 人工膝関節全置換術 / キネマティックアライメント / バイオメカニクス / 人工膝関節置換術

Outline of Final Research Achievements

The plantar pressure distribution was investigated using a pressure plate during walking and one-leg standing among patients after Kinematical alignment TKA (K-TKA), patients after Mechanical alignment TKA (M-TKA), and healthy controls. Conventional and true mechanical axes (the line from the femoral head to the lowest point of the calcaneus) were evaluated on unipedal standing long-leg radiographs. The M-TKA group showed a medial rearfoot loading pattern during walking. On the contrary, the K-TKA and Healthy groups showed an almost equal pressure distribution between the medial and lateral rearfoot. Moreover, although both mechanical axes in the K-TKA group passed through the knee more medially, a more neutral alignment was achieved in the true mechanical axis compared to that in the M-TKA group. K-TKA results in more neutral weight-bearing through the true mechanical axis and allows patients to walk while maintaining medial and lateral rearfoot pressure more evenly than M-TKA.

Academic Significance and Societal Importance of the Research Achievements

Kinematical alignment TKA（K-TKA）がMechanical alignment TKA（M-TKA）と比較して良好な成績を得られる要因の一つに、M-TKAでは足底圧が内側化し、バランス能力低下に影響を与える可能性があると考えられた。
このようにM-TKAと比較した際のK-TKAの良好な成績のメカニズムが解明されていくことが新規のインプラントデザインや手術法の開発の一助となり、それによりTKAの術後成績向上が得られ、健康寿命の延伸や医療費抑制が可能となるなど社会的意義も大きいと考えられる。

Research Products

• [Journal Article] Comparison of plantar pressure distribution during walking and lower limb alignment between modified kinematically and mechanically aligned total knee arthroplasty (2021)
  • Author(s): Tomoyuki Kamenaga, Naoki Nakano, Koji Takayama, Masanori Tsubosaka, Yoshinori Takashima, Kenichi Kikuchi, Masahiro Fujita, Yuichi Kuroda, Shingo Hashimoto, Shinya Hayashi, Takahiro Niikura, Ryosuke Kuroda, Tomoyuki Matsumoto
  • Journal Title: Journal of Biomechanics Volume: 120 Pages: 110379-110379
  • DOI: 10.1016/j.jbiomech.2021.110379
  • Peer Reviewed
• [Presentation] Kinematically aligned TKA とMechanically aligned TKA の歩行時と起立時の足底圧の比較 (2019)
  • Author(s): 亀長 智幸、松本 知之、高山 孝治、林 申也、橋本 慎吾、壺坂 正徳、高島 良典、菊池 健一、藤田 雅広、黒田 良祐
  • Organizer: 第46回日本臨床バイオメカニクス学会