オカザキ　ケン   Okazaki Ken   岡崎　賢    所属   医学部 医学科（東京女子医科大学病院）    職種   教授・基幹分野長
論文種別	原著
言語種別	英語
査読の有無	査読あり
表題	Effects of tibial baseplate shape on rotational alignment in total knee arthroplasty: three-dimensional surgical simulation using osteoarthritis knees.
掲載誌名	正式名：Archives of orthopaedic and trauma surgery 略　 称：Arch Orthop Trauma Surg ISSNコード：14343916/09368051
掲載区分	国外
巻・号・頁	138(1),pp.105-114
著者・共著者	Ma Yuan, Mizu-Uchi Hideki, Okazaki Ken, Ushio Tetsuro, Murakami Koji, Hamai Satoshi, Akasaki Yukio, Nakashima Yasuharu
発行年月	2018/01
概要	INTRODUCTION:Placement of tibial component is expected to fulfill both maximum surface coverage and recommended anterior-posterior (AP) alignment in total knee arthroplasty (TKA). The purpose of this study is to evaluate the effect of the tibial baseplate shape on AP axis.MATERIALS AND METHODS:Virtual surgery of TKA was performed with three-dimensional bone models reconstructed from 77 osteoarthritis varus knees. Two differently designed tibial baseplates, symmetrically and anatomically, were set to the cut surface under posterior slopes of 0°, 3°, and 7°. The AP axes were defined by connecting the geometrical center of the cut surface with the medial edge (axis MED) and medial 1/3 (axis 1/3MED) of patella tendon attachment. We evaluated the overhang rates as well as the most fitting AP axis which passes through the geometric center.RESULTS:Overhang rates when aligned to axis MED were 12-25% for the symmetrical-type group and 13-22% for the anatomical-type group. Overhang rates when aligned to axis 1/3MED were 42-48% for the symmetrical-type group and 3-7% for the anatomical-type group. The most fitting AP axis of tibial baseplate was located 2.5° external to axis MED for the symmetrical-type group and around 3.3° internal to axis 1/3MED for the anatomical-type group.CONCLUSIONS:Symmetrically or anatomically designed tibial baseplates have their own favored AP axis and specific performance on coverage. When aligned to axis 1/3MED, anatomically designed tibial baseplates will effectively lower the mismatch rates compared to a symmetrically designed tibial baseplate. Orthopaedic surgeons are expected to place the tibial components to the cut surface during TKA with full understanding of the features between different baseplate designs, AP axes, and posterior slopes for an ideal tibial rotational position.
DOI	10.1007/s00402-017-2828-2
PMID	29075841