Faculty Profiles - KOBAYASHI Koichi

透視X線画像を用いた人工膝関節単顆置換術前後の三次元運動解析

Other Link： http://hdl.handle.net/10191/26369

透視X線画像を用いた人工膝関節単顆置換術前後のTEAからみた三次元運動解析

望月友晴, 佐藤卓, 山際浩史, 渡辺聡, 谷藤理, 小林公一, 大森豪, 古賀良生, 遠藤直人

JOSKAS 36 ( 4 ) 332 - 332 2011.6

望月友晴, 佐藤卓, 山際浩史, 谷藤理, 小林公一, 古賀良生, 大森豪, 松枝宗則, 遠藤直人

日本整形外科学会雑誌 85 ( 3 ) S352 - S352 2011.3

Experimental validation of femorotibial contact behavior assessed by the image matching method

豊田貴嗣, 小林公一, 坂本信

Japanese journal of clinical biomechanics 32 483 - 487 2011

Estimation of in-vivo quadriceps forces of the KNEE - A combined in-vivo patellofemoral joint kinematics measurement and finite element prediction Reviewed

Koichi Kobayashi, Guoan Li

ASME 2011 Summer Bioengineering Conference, SBC 2011 851 - 852 2011

TKAにおけるTransepicondylar Axisからみた大腿骨顆部形状変化

望月友晴, 佐藤卓, 山際浩史, 小林公一, 渡辺聡, 谷藤理, 大森豪, 古賀良生, 遠藤直人

日本人工関節学会誌 40 592 - 593 2010.12

Language：Japanese Publisher：(一社)日本人工関節学会

従来の方法で人工膝関節全置換術(TKA)を施行した大腿骨における、大腿骨上顆軸(TEA)からみた三次元的な関節表面までの距離とインプラントの三次元的設置角度を評価し、Single radius型のインプラント設置法を再検討した。TKAを施行した40例40膝を対象とした。TKA後、下肢全長2方向CR像に骨とインプラントの三次元形状モデルを重ね合わせ、実際の設置状態を正確に再現した骨-インプラントの三次元モデル複合体を生成した。術後の大腿骨インプラント内外側穎部最遠位点からTEAまでの距離(遠位径)と同最後方点からのTEAまでの距離(後方径)と、インプラント三次元設置角度を評価した。内側においては遠位径-後方径間に有意差は認めなかったが、外側においては後方径が遠位径に比して有意に短かった。内外反・屈曲伸展は概ね良好であったが、回旋角度がTEAに対して内旋傾向であった。

Accuracy of image-matching in a setting method for the stem during total hip arthroplasty using a three-dimension leg alignment assessment systems

KUBOTA Yosuke, SAKAMOTO Makoto, KOBAYASHI Koichi, KOGA Yoshio, MINATO Izumi, ITO Tomoyuki, SEITOKU Norio

Japanese journal of clinical biomechanics 31 313 - 319 2010.9

Development of Automatic Method for Construction of Joint Coordinate System on Tibial 3D Bone Model

KAI Shin, SASAGAWA Keisuke, KOGA Yoshio, SATO Takashi, TANIFUJI Osamu, SAKAMOTO Shin, KOBAYASHI Koichi, TANABE Yuji

Japanese journal of clinical biomechanics 31 333 - 340 2010.9

Transmission characteristics of near-infrared light in articular cartilage

MATSUMOTO Go, ODASHIMA Koki, KIKUCHI Tatsuya, KOBAYASHI Koichi, SAKAMOTO Makoto, TANABE Yuji, KOGA Yoshio

Japanese journal of clinical biomechanics 31 73 - 77 2010.9

In Vivo Structural Analysis of Trabecular Bone of Talus and Calcaneus Using Magnetic Resonance Imaging

SAKAMOTO Makoto, SASAGAWA Keisuke, KUBOTA Yosuke, KOBAYASHI Koichi, YOSHIDA Hidenori

Japanese journal of clinical biomechanics 31 13 - 20 2010.9

Analysis of contact behavior of knee joint using image registration method

ODAGAWA Kenichi, TOYODA Takatsugu, KOBAYASI Koichi, TANIFUJI Osamu, SASAGAWA Keisuke, SATO Takashi, SAKAMOTO Makoto, KOGA Yoshio, TANABE Yuji, OMORI Go

Japanese journal of clinical biomechanics 31 349 - 355 2010.9

Accuracy Estimation of Three-Dimensional Lower Extremity Alignment Assessment System Using MRI Models for Bone and Cartilage

SASAGAWA Keisuke, SAKAMOTO Makoto, KOBAYASHI Koichi, KOGA Yoshio, TANABE Yuji, OMORI Go, SATO Takashi

Japanese journal of clinical biomechanics 31 341 - 348 2010.9

Numerical analysis of pressure on cup surface after THA Reviewed

Kai S, Sakamoto M, Kobayashi K, Minato I, Koga Y, Tanabe Y

Journal of the Japanese Society of Experimental Mechanics 10 ss251 - ss255 2010.8

Language：English Publishing type：Research paper (scientific journal) Publisher：The Japanese Society for Experimental Mechanics

Estimation of the artificial hip joint contact area and pressure distribution during motions of daily life is important in predicting joint degeneration mechanism and implant wear. The purpose of this study was to develop a method of applying discrete element analysis (DEA) based on a rigid body spring model to artificial hip joint, and to analyze contact area and pressure distribution during different motions. Post-operative motion analyses of four basic motions, such as fast walking, slow walking, standing up and sitting down were performed by using VICON system and Kistler force plate. Implant orientation was obtained by matching the contours of 3D bone model and implant CAD model to those of the biplanar CR images. Triangular mesh at interior surface of cup model was considered as liner surface and used for applying DEA to artificial hip joint.Because stem model was considered to be a rigid body and consequential transformations occurred only inside the liner model, triangular mesh was considered to be a compressive spring respectively.The change of contact area and the pressure distribution under dynamic condition were calculated easily through these considerations, and rapid increase accompanied with change of area was observed in knee bending motions.

DOI： 10.11395/jjsem.10.s251

In vivo contact areas of tibiotalar joint measured with magnetic resonance imaging Reviewed

Other Link： http://hdl.handle.net/10191/26374

Sakamoto M, Nodaguchi Y, Tanabe Y, Sasagawa K, Kubota Y, Kobayashi K

Journal of the Japanese Society of Experimental Mechanics 10 ss247 - ss250 2010.8

Accuracy verification of image-matching in a setting method for the stem during total hip arthroplasty Reviewed

Kubota Y, Sakamoto M, Kobayashi K, Koga Y, Tanabe Y

Journal of the Japanese Society of Experimental Mechanics 10 ss234 - ss239 2010.8

Language：English Publishing type：Research paper (scientific journal) Publisher：The Japanese Society for Experimental Mechanics

Currently, stem insertion during total hip arthroplasty (THA) is not well controlled. The present study investigated a method for improving stem setting in accordance with preoperative planning using a three-dimensional (3-D) computed tomography (CT) model of the femur and RGB images of the excised femoral head. We utilized three femoral heads removed during THA and modeled each head using three spherical acrylic markers. Each femoral head was osteotomized using a parallel jig and three rectangular images of the osteotomized head were taken using a CCD camera. Each femoral head was then set on a camera base and RGB images were taken from three orthogonal directions using the CCD camera. The B-images of the femoral head and the 3-D bone model were processed through image-matching software using an automatic outline extraction and downhill simplex method. The position of the contralateral side of the jig, related to the femur, was measured using a 3-D measuring system in order to validate the accuracy of the image-matching. However, since validation of the accuracy of the image-matching is difficult once the femoral head is excised, a six-degree-of-freedom board was used to facilitate the accuracy validation.

DOI： 10.11395/jjsem.10.s247

Three-dimensional In vivo contact analysis of the wrist joint during wrist motion Reviewed

Other Link： http://hdl.handle.net/10191/26371

Sasagawa K, Sakamoto M, Yoshida H, Kobayashi K, Tanabe Y

Journal of the Japanese Society of Experimental Mechanics 10 ss261 - ss266 2010.8

Language：English Publishing type：Research paper (scientific journal) Publisher：The Japanese Society for Experimental Mechanics

The wrist joint is condyloid and capable of movement through two axes: palmar/dorsal flexion and radial/ulnar deviation. Knowledge of in vivo joint mechanics is important for understanding pathological mechanisms and the treatment of various joint problems. The purpose of this study was to investigate the in vivo wrist joint mechanism during wrist motion. In vivo wrist joint contact and the kinematics of the scaphoid and lunate during palmar/dorsal flexion and radial/ulnar deviation were examined using magnetic resonance imaging (MRI). The wrist joints of 15 healthy young volunteers were scanned at 8 positions (.30 deg of palmar flexion; neutral; 30, 60, and 90 deg of dorsal flexion; .20 deg of radial deviation; neutral; and 20 deg of ulnar deviation). Contact of the wrist joint was estimated quantitatively from the derived MR images. Using three-dimensional surface models of the carpal bones, the kinematics of the scaphoid and lunate were analyzed three-dimensionally.

DOI： 10.11395/jjsem.10.s261

Other Link： http://hdl.handle.net/10191/26375

人工膝関節単顆置換術適応症例における術前の三次元膝運動解析

望月友晴, 佐藤卓, 山際浩史, 谷藤理, 小林公一, 古賀良生, 大森豪, 遠藤直人

JOSKAS 35 ( 4 ) 312 - 312 2010.6

Three-dimensional lower extremity alignment in the weight-bearing standing position in healthy elderly subjects Reviewed

Akihiro Ariumi, Takashi Sato, Koichi Kobayashi, Yoshio Koga, Go Omori, Izumi Minato, Naoto Endo

JOURNAL OF ORTHOPAEDIC SCIENCE 15 ( 1 ) 64 - 70 2010.1

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER TOKYO

Although assessment of lower extremity alignment is important for the treatment and evaluation of diseases that present with malalignment of the lower extremity, it has generally been performed using only plain radiographs seen in two dimensions (2D). In addition, there is no consensus regarding the criteria for quantitative three-dimensional (3D) evaluation of the relative angle between the femur and tibia. The purpose of this study was to establish assessment methods and criteria for quantitatively evaluating lower extremity alignment in 3D and to obtain reference data from normal elderly subjects.
The normal alignment of 82 limbs of 45 healthy elderly subjects (24 women, 21 men; mean age 65 years, range 60-81 years) was analyzed in 3D with regard to flexion, adduction-abduction, and rotational angle of the knee in the weight-bearing, standing position. The obtained computed tomography (CT) and biplanar computed radiography (CR) data were used to define several anatomical axes of the femur and tibia as references.
In the sagittal plane, the mean extension-flexion angle was significantly more recurvatum in women than in men. In the coronal plane, the mean 3D hip-knee-ankle angle was more varus by several degrees in this Japanese series than that in a Caucasian series reported previously. Regarding rotational alignment, the mean angle between the anteroposterior axis of the tibia and the transepicondylar axis of the femur in this series was slightly larger (externally rotated) than that of previously reported Japanese series examined in the supine position.
These data are believed to represent important references for 3D evaluation of morbid lower extremity alignment in the weight-bearing, standing position and are important for biomechanical research (e.g., 3D analyses of knee kinematics) because the relative angles between the femur and tibia are assessed three-dimensionally.

DOI： 10.1007/s00776-009-1414-z

Web of Science

PubMed

Automated image registration for assessing three-dimensional alignment of entire lower extremity and implant position using bi-plane radiography Reviewed

Koichi Kobayashi, Makoto Sakamoto, Yuji Tanabe, Akihiro Ariumi, Takashi Sato, Go Omori, Yoshio Koga

JOURNAL OF BIOMECHANICS 42 ( 16 ) 2818 - 2822 2009.12

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCI LTD

An automated image-matching technique is presented to assess alignment of the entire lower extremity for normal and implanted knees and the positioning of implants with respect to bone. Sawbone femur and tibia and femoral and tibial components of a total knee arthroplasty system were used. Three spherical markers were attached to each sawbone and each component to define the local coordinate system. Outlines of the three-dimensional (3D) bone models and component computer-aided design (CAD) models were projected onto extracted contours of the femur, tibia, and implants in frontal and oblique X-ray images. Three-dimensional position of each model was recovered by minimizing the difference between the projected outline and the contour. Median values of the absolute error in estimating relative positions were within 0.5 mm and 0.6 degrees for the femur with respect to the tibia, 0.5 mm and 0.5 degrees for the femoral component with respect to the tibial component, 0.6 mm and 0.6 degrees for the femoral component with respect to the femur, and 0.5 mm and 0.4 degrees for the tibial component with respect to the tibia, indicating significant improvements when compared to manually obtained results. (C) 2009 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.jbiomech.2009.08.022

Web of Science

PubMed