caa a22 4500 605456380 CHVBK 20210128100217.0 cr unu---uuuuu 210128e20150601xx s 000 0 eng 10.1007/s00167-014-3194-z doi (NATIONALLICENCE)springer-10.1007/s00167-014-3194-z Different femorotibial contact on the weight-bearing: midflexion between normal and varus aligned knees after total knee arthroplasty [Elektronische Daten] [Eisaku Fujimoto, Yoshiaki Sasashige, Tetsuya Tomita, Kenji Kashiwagi, Amiko Inoue, Mikiya Sawa, Yuki Ota] Purpose: The influence of residual malalignment on biomechanical analysis after total knee arthroplasty (TKA) is currently uncertain. The hypothesis is that postoperative alignment would influence the in vivo kinematics after TKA, under weight-bearing conditions but not under non-weight-bearing condition. The purpose of the present study was to compare weight-bearing and non-weight-bearing conditions and to evaluate the effect of the postoperative alignment on the in vivo kinematics after posterior cruciate ligament-retaining TKA during midflexion using 2-dimensional/3-dimensional registration. Methods: Thirty knees of 30 patients with pre-operative varus deformity were divided into 2 groups according to their postoperative alignment: the normal alignment group (N=21) and the varus alignment group (N=9). Results: Under weight-bearing conditions, the varus alignment group showed a significant posterior displacement of the medial femoral condyle (flexion: 80°, 90° P<0.05) and a significant anterior displacement of the lateral femoral condyle (flexion: 10° P<0.01, 20° P<0.05, and extension: 10°, 20° P<0.01, 30°, 40° P<0.05) as compared with the normal alignment group. In contrast, no significant difference in the medial and lateral femoral condyle positions under non-weight-bearing conditions was observed between the normal and varus alignment groups. Conclusion: The postoperative alignment influenced knee kinematics under weight-bearing conditions. The weight load influenced knee kinematics through posterior tibial slope and induced greater lateral femoral condyle mobility, which might explain the better clinical and functional outcome. These findings contribute to gaining a proper understanding of the in vivo kinematics of the postoperative varus alignment and might be useful for orthopaedic surgeons in the achievement of patient satisfaction. Level of evidence: III. Springer-Verlag Berlin Heidelberg, 2014 Kinematics nationallicence Cruciate-retaining total knee arthroplasty nationallicence 2D/3D registration nationallicence Posterior cruciate ligament nationallicence Postoperative alignment nationallicence Varus nationallicence Screw-home movement nationallicence Fujimoto Eisaku Department of Orthopedic Surgery, Chugoku Rousai Hospital, 1-5-1 Hirotagaya, 737-0193, Kure, Hiroshima, Japan aut Sasashige Yoshiaki Department of Orthopedic Surgery, Chugoku Rousai Hospital, 1-5-1 Hirotagaya, 737-0193, Kure, Hiroshima, Japan aut Tomita Tetsuya Department of Orthopedic Biomaterial Science, Osaka University Graduate School of Medicine, Suita, Osaka, Japan aut Kashiwagi Kenji Department of Orthopedic Surgery, Chugoku Rousai Hospital, 1-5-1 Hirotagaya, 737-0193, Kure, Hiroshima, Japan aut Inoue Amiko Department of Orthopedic Surgery, Chugoku Rousai Hospital, 1-5-1 Hirotagaya, 737-0193, Kure, Hiroshima, Japan aut Sawa Mikiya Department of Orthopedic Surgery, Chugoku Rousai Hospital, 1-5-1 Hirotagaya, 737-0193, Kure, Hiroshima, Japan aut Ota Yuki Department of Orthopedic Surgery, Chugoku Rousai Hospital, 1-5-1 Hirotagaya, 737-0193, Kure, Hiroshima, Japan aut Knee Surgery, Sports Traumatology, Arthroscopy Springer Berlin Heidelberg 23/6(2015-06-01), 1720-1728 0942-2056 23:6<1720 2015 23 167 https://doi.org/10.1007/s00167-014-3194-z text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00167-014-3194-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Fujimoto Eisaku Department of Orthopedic Surgery, Chugoku Rousai Hospital, 1-5-1 Hirotagaya, 737-0193, Kure, Hiroshima, Japan aut NATIONALLICENCE 700 1- Sasashige Yoshiaki Department of Orthopedic Surgery, Chugoku Rousai Hospital, 1-5-1 Hirotagaya, 737-0193, Kure, Hiroshima, Japan aut NATIONALLICENCE 700 1- Tomita Tetsuya Department of Orthopedic Biomaterial Science, Osaka University Graduate School of Medicine, Suita, Osaka, Japan aut NATIONALLICENCE 700 1- Kashiwagi Kenji Department of Orthopedic Surgery, Chugoku Rousai Hospital, 1-5-1 Hirotagaya, 737-0193, Kure, Hiroshima, Japan aut NATIONALLICENCE 700 1- Inoue Amiko Department of Orthopedic Surgery, Chugoku Rousai Hospital, 1-5-1 Hirotagaya, 737-0193, Kure, Hiroshima, Japan aut NATIONALLICENCE 700 1- Sawa Mikiya Department of Orthopedic Surgery, Chugoku Rousai Hospital, 1-5-1 Hirotagaya, 737-0193, Kure, Hiroshima, Japan aut NATIONALLICENCE 700 1- Ota Yuki Department of Orthopedic Surgery, Chugoku Rousai Hospital, 1-5-1 Hirotagaya, 737-0193, Kure, Hiroshima, Japan aut NATIONALLICENCE 773 0- Knee Surgery, Sports Traumatology, Arthroscopy Springer Berlin Heidelberg 23/6(2015-06-01), 1720-1728 0942-2056 23:6<1720 2015 23 167