Faculty Profiles - KOBAYASHI Koichi

Papers - KOBAYASHI Koichi

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Effect on inclined medial proximal tibial articulation for varus alignment in advanced knee osteoarthritis. Reviewed International journal

Mochizuki T, Koga Y, Tanifuji O, Sato T, Watanabe S, Koga H, Kobayashi K, Omori G, Endo N

Journal of experimental orthopaedics 6 ( 1 ) 14 - 14 2019.3

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: The inclination of the medial compartment of the proximal tibia (MCT) is assumed to be a critical factor for varus alignment in advanced knee osteoarthritis (OA). This study was aimed at investigating; (1) whether the inclination of MCT is aligned parallel to the ground under weight-bearing (WB) conditions; (2) whether this is associated with the change in alignment and the relative position between the bones; and (3) whether the tibia or femur mainly contributes to the changes. METHODS: We examined 102 knees (84 women, 18 men; mean 75 years). A three-dimensional (3D) assessment system was applied on biplanar whole lower extremity radiographies using 3D-to-2D image registration technique. The evaluation parameters were 1) MCT angle, 2) femorotibial angle (FTA), 3) medial-lateral femoral location to the tibia (M-L femoral location), 4) WB line passing point, and 5) tibial position to WB line (tibial position) and 6) femoral postion to WB line (femoral position). Each parameter was evaluated in non-WB and WB conditions, and the differences (Δ-parameters). RESULTS: MCT angle in the world coordinate system was larger than that in the tibial coordinate system (p < 0.0001). ΔMCT angle was correlated with ΔFTA (p = 0.002) and ΔM-L femoral location (p = 0.004). The tibial position was the more dominant factor for ΔMCT angle (p = 0.001), ΔFTA (p < 0.0001), and ΔWB line passing point (p < 0.0001) . CONCLUSIONS: The inclination in MCT was aligned parallel to the ground under WB conditions (tibial parallel phenomenon). The parallel phenomenon was associated with the change of alignment and the relative position between the bones in the coronal plane. These phenomena were produced mainly by the tibia, not the femur. LEVEL OF EVIDENCE: Level IV.

DOI： 10.1186/s40634-019-0180-x

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進行期変形性膝関節症患者における脛骨近位内側関節面の水平化機序三次元評価による臥位と立位の比較

望月友晴, 谷藤理, 古賀良生, 森隆弘, 小林公一, 古賀寛, 大森豪, 遠藤直人

日本整形外科学会雑誌 93 ( 3 ) S587 - S587 2019.3

健常例における三次元大腿骨皮質骨幅計測と比較検討若年男女vs.高齢男女

染矢圭一郎, 望月友晴, 穂苅翔, 谷藤理, 遠藤直人, 小林公一

日本整形外科学会雑誌 93 ( 3 ) S743 - S743 2019.3

MRIの3次元撮像法とCine法のイメージマッチングを用いた膝蓋腱の長さ変化測定

近藤達也, 坂本信, 小林公一, 金沢勉, 斉藤宏明

日本放射線技術学会総会学術大会予稿集 75回 149 - 149 2019.3

Ultrasound elastographic assessment of the stiffness of the anteromedial knee joint capsule at varying knee angles. Reviewed International journal

Surangika Wadugodapitiya, Makoto Sakamoto, Kaito Sugita, Yusuke Morise, Masaei Tanaka, Koichi Kobayashi

Bio-medical materials and engineering 30 ( 2 ) 219 - 230 2019

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: In vivo evaluation of the elastic properties of the knee joint capsule has not been adequately performed. OBJECTIVES: To establish a methodology to assess the stiffness of the normal knee joint capsule over a range of knee flexion angles using ultrasound elastography. METHODS: Ultrasound elastography with an acoustic coupler was used to assess the stiffness of the anteromedial capsule of the knee joints of 10 male (mean age 22.63 ± 1.02 years) and 10 female (mean age 21.6 ± 0.8 years) subjects at static knee flexion angles of 0°, 45°, 90°, and 120°. Relative stiffness of the capsule was obtained using the strain ratio (SR), defined as the ratio of the strain in the capsule to that in the acoustic coupler. RESULTS: The intraclass correlation coefficient (1, 3) ranged from 0.95 to 0.96, and the correlation coefficient between examiners (2, 3) was 0.94. SR values decreased significantly as the flexion angle increased (P < 0.01). At 90° and 120°, it was significantly higher in female than in male subjects (P < 0.01). CONCLUSIONS: This study established a feasible and reproducible method to obtain the stiffness characteristics of the anteromedial knee joint capsule using ultrasound elastography with an acoustic coupler.

DOI： 10.3233/BME-191046

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In Vivo Strain Ultrasound Elastographic Assessment of the Stiffness of the Medial Collateral Ligament at Varying Knee Flexion Angles

SAKAMOTO Makoto, WADUGODAPITIYAI Surangika, MORISE Yusuke, TANAKA Masaei, KOBAYASHI Koichi

The Proceedings of Mechanical Engineering Congress, Japan 2019 J02513 2019

DRR画像を用いた二次元画像上の大腿骨・脛骨間の回旋評価法の精度検証

森隆裕, 古賀良生, 小林公一, 古賀寛, 望月友晴, 勝見亮太, 大森豪, PRAMUDITA Jonas Aditya, 田邊裕治

臨床バイオメカニクス 39 125‐129 - 129 2018.10

コーンビームCTによる前歯部の三次元自動歯軸および歯列決定法

坂本信, 坂上勇太, 森清友亮, 亀田剛, 小林公一, 坂井幸子, 遠藤英昭

臨床バイオメカニクス 39 207‐216 - 216 2018.10

核磁気共鳴画像法を用いた母指指節間関節および中手指節関節の三次元生体内接触運動解析

杉田魁人, 坂本信, 森清友亮, 風間清子, 小林公一, 田邊裕治

臨床バイオメカニクス 39 237‐246 - 246 2018.10

骨盤姿勢を考慮した三次元下肢アライメント評価の精度検証

五十嵐良樹, 佐藤卓, 小林公一, 田邊裕治, PRAMUDITA Jonas Aditya

臨床バイオメカニクス 39 149‐152 2018.10

大腿脛骨軟骨間の接触動態と相対滑り量の検討

中原大輔, 小林公一, 坂本信, 佐藤卓, 渡邉聡, 大森豪, 古賀良生, PRAMUDITA Jonas Aditya, 田邊裕治

臨床バイオメカニクス 39 299‐303 2018.10

二方向スロットラジオグラフィを用いた自動イメージマッチング法の開発

岡庭大祐, 中原大輔, 小林公一, 坂本信, 田邊裕治, PRAMUDITA Jonas, Aditya, 佐藤卓, 大森豪, 湊泉, 古賀良生

臨床バイオメカニクス 39 143‐148 2018.10

Analytical solution of axisymmetric indentation of an elastic layer-substrate body Reviewed

Kotaro MIURA, Makoto SAKAMOTO, Koichi KOBAYASHI, Jonas A, PRAMUDITA, Yuji TANABE

Theretical and Applied Mechanics 67 81 - 101 2018.10

Language：English Publishing type：Research paper (scientific journal) Publisher：National Committee for IUTAM

We focus on an elastic contact problem for indentation of a layer-substrate body. An elastic layer assumed to be perfectly bonded to an elastic semi-infinite substrate. The elastic layer is smoothly indented with a flat-ended cylindrical indenter and a spherical indenter. The analytical and exact solutions are obtained by solving an infinite system of simultaneous equations using the method to express a normal contact stress at the upper surface of the elastic layer as an appropriate series. This paper presents not only the axial load but also the distribution of the dimensionless normal contact stress under cylindrical and spherical indentation, the distribution of the dimensionless normal displacement at the upper surface of the elastic layer and the stress singularity factor. Numerical results are given for several combinations of the ratio of shear modulus and Poisson’s ratios of the elastic layer and substrate, and the thickness of the elastic layer.

DOI： 10.11345/nctam.64.81

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Correlation between posterior tibial slope and sagittal alignment under weight-bearing conditions in osteoarthritic knees Reviewed International journal

Mochizuki Tomoharu, Tanifuji Osamu, Koga Yoshio, Sato Takashi, Kobayashi Koichi, Watanabe Satoshi, Fujii Toshihide, Yamagiwa Hiroshi, Katsumi Ryota, Koga Hiroshi, Omori Go, Endo Naoto

PLOS ONE 13 ( 9 ) e0202488 2018.9

脛骨近位内側関節面傾斜の健常者と進行期変形性膝関節症患者の三次元評価―臥位と立位での変化―

望月友晴, 谷藤理, 古賀良生, 森隆裕, 佐藤卓, 渡辺聡, 大森豪, 小林公一, 西野勝敏, 田邊裕治, 遠藤直人

日本整形外科学会雑誌 92 ( 8 ) S2016 - S2016 2018.8

Analysis of in vivo static contact surface motion of thumb interphalangeal joint Reviewed

Yusuke MORISE, Makoto SAKAMOTO, Kaito SUGITA, Kiyoko KAZAMA, Koichi KOBAYASHI, Yuji TANABE

Advenced Experimental Mechanics 3 209 - 214 2018.8

Contribution of sex and body constitution to three-dimensional lower extremity alignment for healthy, elderly, non-obese humans in a Japanese population. Reviewed International journal

Katsumi R, Mochizuki T, Sato T, Kobayashi K, Watanabe S, Tanifuji O, Endo N

Journal of experimental orthopaedics 5 ( 1 ) 32 - 32 2018.8

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Humans support their bodies exclusively by vertical balance in bipedal locomotion, and the body, especially the lower extremity, generally changes with age. Sex and body constitution are assumed to be associated with lower extremity alignment, but this association remains to be elucidated. This study sought to clarify this association in healthy, elderly, non-obese humans in a Japanese population. METHODS: The present study investigated 55 healthy volunteers (mean age: 70 ± 6 years). A 3D extremity alignment system was applied under weight-bearing conditions on biplane long lower extremities X-rays using a 3D-to-2D image registration technique. The evaluation parameters included 3D hip-knee-ankle angle (3DHKA) alignment in the coronal (coronal alignment) and sagittal planes (sagittal alignment) and rotational alignment between the femur and tibia. The influences of sex and body constitution on all the alignment were analyzed. RESULTS: Multiple linear regression analysis with the dependent variable of each alignment showed that sex was the dominant factor for coronal and rotational alignment (coronal: p < 0.01; rotational: p < 0.01), and body weight was the dominant factor for sagittal alignment (p < 0.01). CONCLUSIONS: The association of sex with coronal and rotational alignment and of body constitution with sagittal alignment were proved in healthy, elderly, non-obese humans in a Japanese population. This finding can lead to further understanding of the etiology of many diseases and age-related changes.

DOI： 10.1186/s40634-018-0147-3

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Extrinsic Factors as Component Positions to Bone and Intrinsic Factors Affecting Postoperative Rotational Limb Alignment in Total Knee Arthroplasty Reviewed

Tomoharu Mochizuki, Takashi Sato, Osamu Tanifuji, Satoshi Watanabe, Koichi Kobayashi, Naoto Endo

Journal of Arthroplasty 33 ( 7 ) 2100 - 2110 2018.7

関節のバイオメカニクス核磁気共鳴画像法による示指中手指節関節の三次元生体内接触運動の解析

坂本信, 小林公一, 春日勇人, 風間清子

非破壊検査 67 ( 4 ) 174‐179 - 179 2018.4

An analytical solution for the axisymmetric problem of a penny-shaped crack in an elastic layer sandwiched between dissimilar materials Reviewed

Miura Kotaro, Sakamoto Makoto, Kobayashi Koichi, Pramudita Jonas A, Tanabe Yuji

MECHANICAL ENGINEERING JOURNAL 5 ( 3 ) 18 - 00125-18-00125 2018

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