Geert Peersman1,2, Josh Slane3, Philippe Vuylsteke4, Susanne Fuchs-Winkelmann5, Philipp Dworschak5, Thomas Heyse5, Lennart Scheys3. 1. Institute for Orthopaedic Research and Training, KU Leuven, Campus Pellenberg, Louvain, Belgium. geert.peersman@telenet.be. 2. Department of Orthopaedic Surgery, Ziekenhuis Netwerk Antwerp, Campus Stuivenberg, Antwerp, Belgium. geert.peersman@telenet.be. 3. Institute for Orthopaedic Research and Training, KU Leuven, Campus Pellenberg, Louvain, Belgium. 4. Department of Orthopaedic Surgery, Ziekenhuis Netwerk Antwerp, Campus Stuivenberg, Antwerp, Belgium. 5. Center of Orthopedics and Trauma Surgery, University Hospital Marburg, Marburg, Germany.
Abstract
INTRODUCTION: Fixed-bearing unicompartmental knee arthroplasty (UKA) closely replicates native knee kinematics. As few studies have assessed kinematics following mobile-bearing (MB) UKA, the current study aimed to investigate whether MB UKA preserves natural knee kinematics. MATERIALS AND METHODS: Seven fresh-frozen full-leg cadaver specimens were prepared and mounted in a kinematic rig that allowed all degrees of freedom at the knee. Three motion patterns, passive flexion-extension (0°-110° flexion), open-chain extension (5°-70° flexion) and squatting (30°-100° flexion), were performed pre- and post-implantation of a medial MB UKA and compared in terms of rotational and translational knee joint kinematics in the different anatomical planes, respectively. RESULTS: In terms of frontal plane rotational kinematics, MB UKA specimens were in a more valgus orientation for all motion patterns. In the axial plane, internal rotation of the tibia before and after UKA was consistent, regardless of motion task, with no significant differences. In terms of frontal plane, i.e., inferior-superior, translations, the FMCC was significantly higher in UKA knees in all flexion angles and motor tasks, except in early flexion during passive motion. In terms of axial plane, i.e., anteroposterior (AP), translations, during open-chain activities, the femoral medial condyle center (FMCC) tended to be more posterior following UKA relative to the native knee in mid-flexion and above. AP excursions of the FMCC were small in all tested motions, however. There was substantial AP translation of the femoral lateral condyle center during passive motion before and after UKA, which was significantly different for flexion angles > 38°. CONCLUSIONS: Our study data demonstrate that the kinematics of the unloaded knee following MB UKA closely resemble those of the native knee while relative medial overstuffing with UKA will result in the joint being more valgus. However, replacing the conforming and rigidly fixed medial meniscus with a mobile inlay may successfully prevent aberrant posterior translation of the medial femoral compartment during passive motion and squatting motion.
INTRODUCTION: Fixed-bearing unicompartmental knee arthroplasty (UKA) closely replicates native knee kinematics. As few studies have assessed kinematics following mobile-bearing (MB) UKA, the current study aimed to investigate whether MB UKA preserves natural knee kinematics. MATERIALS AND METHODS: Seven fresh-frozen full-leg cadaver specimens were prepared and mounted in a kinematic rig that allowed all degrees of freedom at the knee. Three motion patterns, passive flexion-extension (0°-110° flexion), open-chain extension (5°-70° flexion) and squatting (30°-100° flexion), were performed pre- and post-implantation of a medial MB UKA and compared in terms of rotational and translational knee joint kinematics in the different anatomical planes, respectively. RESULTS: In terms of frontal plane rotational kinematics, MB UKA specimens were in a more valgus orientation for all motion patterns. In the axial plane, internal rotation of the tibia before and after UKA was consistent, regardless of motion task, with no significant differences. In terms of frontal plane, i.e., inferior-superior, translations, the FMCC was significantly higher in UKA knees in all flexion angles and motor tasks, except in early flexion during passive motion. In terms of axial plane, i.e., anteroposterior (AP), translations, during open-chain activities, the femoral medial condyle center (FMCC) tended to be more posterior following UKA relative to the native knee in mid-flexion and above. AP excursions of the FMCC were small in all tested motions, however. There was substantial AP translation of the femoral lateral condyle center during passive motion before and after UKA, which was significantly different for flexion angles > 38°. CONCLUSIONS: Our study data demonstrate that the kinematics of the unloaded knee following MB UKA closely resemble those of the native knee while relative medial overstuffing with UKA will result in the joint being more valgus. However, replacing the conforming and rigidly fixed medial meniscus with a mobile inlay may successfully prevent aberrant posterior translation of the medial femoral compartment during passive motion and squatting motion.
Authors: Mustafa Hariri; Georg Hauer; Maria Smolle; Patrick Sadoghi; Andreas Leithner; Benjamin Panzram; Christian Merle; Tobias Renkawitz; Tilman Walker Journal: Arch Orthop Trauma Surg Date: 2022-09-28 Impact factor: 2.928
Authors: Geert Peersman; Orcun Taylan; Joshua Slane; Ben Vanthienen; Jeroen Verhaegen; Lyne Anthonissen; G Harry van Lenthe; Thomas Heyse; Lennart Scheys Journal: Clin Orthop Relat Res Date: 2020-09 Impact factor: 4.755
Authors: K Sekiguchi; S Nakamura; S Kuriyama; K Nishitani; H Ito; Y Tanaka; M Watanabe; S Matsuda Journal: Bone Joint Res Date: 2019-04-02 Impact factor: 5.853