Kohei Nakajima

Publications (8)12.41 Total impact

• Source

  Available from: Shuji Taketomi

  Article: Immunohistological analysis of extracted anterior cruciate ligament graft impinged against posterior cruciate ligament.

  So Kato, Atsushi Fukai, Hideki Takeda, Shuji Taketomi, Shuichi Nakayama, Jinso Hirota, Kohei Nakajima, Kozo Nakamura, Takumi Nakagawa
  [show abstract] [hide abstract]
  ABSTRACT: A young female athlete suffered from the residual instability of the knee after anterior cruciate ligament (ACL) reconstruction with hamstring autograft. The 3-dimensional (3-D) CT scan showed the "high noon" positioning of the primary femoral bone tunnel. The revision surgery with anatomic double-bundle technique was performed two years after the primary surgery and the femoral tunnels were created with the assistance of the 3-D fluoroscopy-based navigation. An arthroscopic examination confirmed the ACL graft impingement against posterior cruciate ligament (PCL) when the knee was deeply flexed. The histological analysis of the resected primary ACL graft showed local inflammatory infiltration, enhanced synovial coverage and vascularization at the impinged site. The enhanced expression of vascular endothelial growth factor (VEGF) at the impinged area when compared with non-impinged area was observed on immunohistochemical analysis. Abnormal mechanical stress by the impingement against PCL might have induced chronic inflammation and VEGF overexpression.
  Sports Medicine Arthroscopy Rehabilitation Therapy & Technology 11/2011; 3(1):26.
• Article: Osteochondral autograft for medial femoral condyle chondral lesions in a patient with multiple epiphyseal dysplasia: long-term result.

  Shuji Taketomi, Hisatada Hiraoka, Takumi Nakagawa, Yoshinari Miyamoto, So Kuribayashi, Akira Fukuda, Hideki Takeda, Atsushi Fukai, Jinso Hirota, Kohei Nakajima, Nobuhiko Haga, Kozo Nakamura
  Journal of Orthopaedic Science 05/2011; 17(4):507-11. · 0.84 Impact Factor
• Article: Anatomical placement of double femoral tunnels in anterior cruciate ligament reconstruction: anteromedial tunnel first or posterolateral tunnel first?

  Shuji Taketomi, Takumi Nakagawa, Hideki Takeda, Kohei Nakajima, Shuichi Nakayama, Atsushi Fukai, Jinso Hirota, Yoshinori Kachi, Hirotaka Kawano, Toshiki Miura, Naoshi Fukui, Kozo Nakamura
  [show abstract] [hide abstract]
  ABSTRACT: The purpose of this study was to know which tunnel--the anteromedial (AM) bundle or the posterolateral (PL) bundle--should be prepared first to create the 2 femoral tunnels accurately in anatomic double-bundle (DB) anterior cruciate ligament (ACL) reconstruction. Thirty-four patients were divided into 2 groups of 17 depending on the sequence of preparation of the 2 femoral tunnels. In group A, the AM tunnel was prepared first, whereas the PL tunnel was prepared first in group P. ACL reconstruction was performed using a three-dimensional (3-D) fluoroscopy-based navigation system to place the double femoral tunnels through an accessory medial portal. The double femoral socket positioning was evaluated by 3-D computed tomography (CT) scan image. The non-anatomical placement of the femoral sockets occurred in 5 patients (29%) in group A, whereas the 2 sockets were placed anatomically in all patients in group P (P < 0.05). Evaluation of the AM and the PL socket location on the 3-D CT images using the quadrant method showed more similar values to the laboratory data in a literature in group P than in group A. No complication occurred in group A, whereas complications such as socket communications or back wall blowout occurred in 5 patients (29%) in group P (P < 0.05). The sequence of creating 2 femoral tunnels through accessory medial portal affected the resultant location of the sockets and the rate of the complications. When femoral tunnels are prepared with a transportal technique, PL tunnel first technique seems to be superior to AM first technique regarding anatomic placement. However, PL tunnel first technique accompanies the risk of socket communication.
  Knee Surgery Sports Traumatology Arthroscopy 03/2011; 19(3):424-31. · 2.21 Impact Factor
• Source

  Available from: Shimpei Higo

  Article: Comparison of sex-steroid synthesis between neonatal and adult rat hippocampus.

  Shimpei Higo, Yasushi Hojo, Hirotaka Ishii, Toshihiro Kominami, Kohei Nakajima, Donald Poirier, Tetsuya Kimoto, Suguru Kawato
  [show abstract] [hide abstract]
  ABSTRACT: Sex-steroid synthesis in the hippocampus had been thought to be much more active at the neonatal stage than at the adult stage. However, the detailed comparison between these two stages had not been demonstrated yet. Here we performed the comparison about the mRNA level of steroidogenic enzymes and the rate of steroid metabolism between these two stages of the hippocampus. The relative expression level of P450(17alpha), 17beta- or 3beta-hydroxysteroid dehydrogenase, or P450arom was approximately 1.3-1.5-fold higher at the neonatal than at the adult stage. The rate of sex-steroid metabolism (from dehydroepiandrosterone to estradiol) was 2-7-fold (depending on different steps) more rapid at the neonatal than at the adult stage. Taken together, neonatal steroidogenesis is moderately more active than adult steroidogenesis.
  Biochemical and Biophysical Research Communications 06/2009; 385(1):62-6. · 2.48 Impact Factor
• Article: Intraoperative 3-dimensional imaging-based navigation-assisted anatomic double-bundle anterior cruciate ligament reconstruction.

  Takumi Nakagawa, Hideki Takeda, Kohei Nakajima, Shuichi Nakayama, Atsushi Fukai, Yoshinori Kachi, Hirotaka Kawano, Toshiki Miura, Kozo Nakamura
  [show abstract] [hide abstract]
  ABSTRACT: In anatomic double-bundle anterior cruciate ligament (ACL) reconstruction, it is more technically demanding, even for experienced surgeons, to place 2 femoral tunnels within the ACL attachment than to place 2 tibial tunnels. We describe a technique using a three-dimensional (3-D) fluoroscopy-based navigation system to place 2 femoral tunnels accurately. After a reference frame is rigidly attached to the femur, an intraoperative image of the distal femur is obtained. The image is transferred to a navigation system and reconstructed into a 3-D image. During the placement of guidewires for the femoral tunnels through an accessory medial portal, a femoral guide with a tracker feeds back to the surgeons the direction of the guidewire on the 3-D femur bone surface image in real-time. The femoral guide is placed at the center of the footprint with the aid of visual guidance of the navigation and an arthroscopic view. The flexion angle of the knee is then adjusted to prevent posterior blowout on the computer screen during insertion of the guidewire. The length of the femoral tunnel can also be estimated before overdrilling the guidewire. This technology allows surgeons to place 2 femoral tunnels precisely without any complication during anatomic double-bundle ACL reconstruction.
  Arthroscopy The Journal of Arthroscopic and Related Surgery 11/2008; 24(10):1161-7. · 3.02 Impact Factor
• Article: Addition of an arch support improves the biomechanical effect of a laterally wedged insole.

  Kohei Nakajima, Wataru Kakihana, Takumi Nakagawa, Hiroyuki Mitomi, Atsuhiko Hikita, Ryuji Suzuki, Masami Akai, Tsutomu Iwaya, Kozo Nakamura, Naoshi Fukui
  [show abstract] [hide abstract]
  ABSTRACT: In order to examine if the addition of an arch support could improve the biomechanical effect of the laterally wedged insole, three-dimensional gait analysis was performed on 20 healthy volunteers. Kinetic and kinematic parameters at the knee and subtalar joints were compared among the following four types of insoles; a 5-mm thick flat insole, a flat insole with an arch support (AS), a 6 degrees inclined laterally wedged insole (LW), and a laterally wedged insole with an arch support (LWAS). The knee adduction moment averaged for the entire stance phase was reduced by the use of LW and LWAS by 7.7% and 13.3%, respectively, from that with FLAT. The difference in knee adduction moment between LW and LWAS was most obvious in the late stance, which was ascribed to the difference in the progression angle between those insoles. The analyses also revealed that LW tended to increase step width, and that such an increase was completely eliminated by the addition of an arch support to LW. This reduction of step width could be another mechanism for the further reduction of the moment with LWAS. The analyses of biomechanical parameters at the subtalar joints suggested that LWAS allowed the subject to walk in a more natural manner, while exerting greater biomechanical effects than LW. Thus, the addition of an arch support to the laterally wedged insole reduced knee adduction moment more efficiently, possibly through the elimination of potential negative effects of the laterally wedged insole.
  Gait & posture 10/2008; 29(2):208-13. · 2.58 Impact Factor
• Article: Soft textural and emulsifiable gelatin formed by conjugating with fatty-acylated saccharide.

  Kohei Nakajima, Mai Sato, Makoto Hattori, Tadashi Yoshida, Keiji Yoshimura, Koji Takahashi
  [show abstract] [hide abstract]
  ABSTRACT: Ossein gelatin (OG) and low-molecular-weight ossein gelatin (LOG) were conjugated with a glucose/fructose stearic acid monoester (GE/FE), which had been prepared from the hydrolysate of a sucrose stearic acid diester, by the Maillard reaction to improve their physical properties. The molar ratio of each conjugate (GE/FE-OG or GE/FE-LOG) was about 1:1, and the conjugation resulted in a decreased isoelectric point. The GE/FE-OG gel showed a lower storage modulus, melting temperature, and enthalpy change than those for the OG gel at both the early and late stages of gelation, and each gel at pH 3.0 showed somewhat lower characteristics than those at pH 7.0. The conjugates acquired superior emulsifying ability, GE/FE-LOG in particular exhibiting markedly higher emulsifying ability in the acidic pH range, in the presence of NaCl, and over a wide temperature range. It is thus expected that conjugation with GE/FE could be effective for providing a new type of gelatin with a soft texture, easy melting, and emulsifying ability.
  Bioscience Biotechnology and Biochemistry 03/2008; 72(2):295-302. · 1.28 Impact Factor
• Article: [Non-surgical treatments for Gonarthrosis].

  Hisatada Hiraoka, Kohei Nakajima, Hiromi Oda
  [show abstract] [hide abstract]
  ABSTRACT: The cause or progression of gonarthrosis have multifactor. Many varieties of treatments for this degenerative disease exist and indications of the treatments are complicated. Non-surgical treatments for gonarthrosis including quadriceps strengthen exercise and insole therapy were summarized. Further, force distribution in foot prints wearing one of three type of insole, lateral wedged, arch supported or combined insoles, were investigated using F-scan system, and different dynamic mechanisms of three types of insoles were revealed.
  Clinical calcium 02/2002; 12(1):92-7.