Open AccessEffect of tibial component alignment on knee kinematics and ligament tension in medial unicompartmental knee arthroplasty
Author(s) -
Kenichi Sekiguchi,
Shinichiro Nakamura,
Shinichi Kuriyama,
Kohei Nishitani,
Hiromu Ito,
Yoshihisa Tanaka,
Mutsumi Watanabe,
Shinya Matsuda
Publication year - 2019
Publication title -
bone and joint research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.639
H-Index - 31
ISSN - 2046-3758
DOI - 10.1302/2046-3758.83.bjr-2018-0208.r2
Subject(s) - sagittal plane , coronal plane , unicompartmental knee arthroplasty , medicine , posterior cruciate ligament , tibia , orthodontics , femur , valgus , anterior cruciate ligament , osteoarthritis , kinematics , anatomy , ligament , knee joint , surgery , physics , pathology , classical mechanics , alternative medicine
Objectives Unicompartmental knee arthroplasty (UKA) is one surgical option for treating symptomatic medial osteoarthritis. Clinical studies have shown the functional benets of UKA; however, the optimal alignment of the tibial component is still debated. The purpose of this study was to evaluate the effects of tibial coronal and sagittal plane alignment in UKA on knee kinematics and cruciate ligament tension, using a musculoskeletal computer simulation.Methods The tibial component was first aligned perpendicular to the mechanical axis of the tibia, with a 7° posterior slope (basic model). Subsequently, coronal and sagittal plane alignments were changed in a simulation programme. Kinematics and cruciate ligament tensions were simulated during weight-bearing deep knee bend and gait motions. Translation was defined as the distance between the most medial and the most lateral femoral positions throughout the cycle.Results The femur was positioned more medially relative to the tibia, with increasing varus alignment of the tibial component. Medial/lateral (ML) translation was smallest in the 2° varus model. A greater posterior slope posteriorized the medial condyle and increased anterior cruciate ligament (ACL) tension. ML translation was increased in the > 7° posterior slope model and the 0° model.Conclusion The current study suggests that the preferred tibial component alignment is between neutral and 2° varus in the coronal plane, and between 3° and 7° posterior slope in the sagittal plane. Varus > 4° or valgus alignment and excessive posterior slope caused excessive ML translation, which could be related to feelings of instability and could potentially have negative effects on clinical outcomes and implant durability. Cite this article: K. Sekiguchi, S. Nakamura, S. Kuriyama, K. Nishitani, H. Ito, Y. Tanaka, M. Watanabe, S. Matsuda. Bone Joint Res 2019;8:126–135. DOI: 10.1302/2046-3758.83.BJR-2018-0208.R2.