Patient-specific design for articular surface conformity to preserve normal knee mechanics in posterior stabilized total knee arthroplasty

Article type: Research Article

Authors: Koh, Yong-Gon^{a; †} | Son, Juhyun^{b; †} | Kwon, Oh-Ryong^a | Kwon, Sae Kwang^a | Kang, Kyoung-Tak^b;

Affiliations: [a] Joint Reconstruction Center, Department of Orthopaedic Surgery, Yonsei Sarang Hospital, Seoul, Republic of Korea | [b] Department of Mechanical Engineering, Yonsei University, Seoul, Republic of Korea

Correspondence: [*] Corresponding author: Kyoung-Tak Kang, Ph.D. Department of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea. Tel.: +82 2 2123 4827; Fax: +82 2 362 2736; E-mail: tagi1024@gmail.com

Note: [†] Yong-Gon Koh and Juhyun Son contributed equally to this work and should be considered co-first authors.

Abstract: Background:Contemporary total knee arthroplasty (TKA) provides remarkable clinical benefits. However, the normal function of the knee is not fully restored. Recent improvements in imaging and manufacturing have utilized the development of customized design to fit the unique shape of individual patients. Objective:The purpose of the present study is to investigate the preservation of normal knee biomechanics by using specific articular surface conformity in customized posterior stabilized (PS)-TKA. Methods:This includes customized PS-TKA, PS-TKA with conforming conformity (CPS-TKA), medial pivot conformity with PS-TKA (MPS-TKA), and PS-TKA with mimetic anatomy femoral and tibial articular surface (APS-TKA). In this study, kinematics, collateral ligament force and quadriceps force were evaluated using a computational simulation under a deep knee bend condition. Results:A conventional TKA did not provide the normal internal tibial rotation with flexion leading to abnormal femoral rollback. The APS-TKA exhibited normal-like femoral rollback kinematics but did not exhibit normal internal tibial rotation. However, APS-TKA exhibited the most normal-like collateral ligament and quadriceps forces. Conclusions:Although the APS-TKA exhibited more normal-like biomechanics, it did not restore normal knee biomechanics owing to the absence of the cruciate ligament and post-cam mechanism.

Keywords: Patient-specific implant, total knee arthroplasty, conformity, finite element analysis

DOI: 10.3233/BME-180998

Journal: Bio-Medical Materials and Engineering, vol. 29, no. 4, pp. 401-414, 2018