Papers by Author: Hirotaka Mutsuzaki

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Authors: Shinobu Kobayashi, Masataka Sakane, Hirotaka Mutsuzaki, Hiromi Nakajima, M. Tanaka, Yutaka Miyanaga, Naoyuki Ochiai
Abstract: We hybridized calcium phosphate (CaP) with human semitendinosus and gracilis (ST/G) tendon grafts using an alternate soaking process. To evaluate quantitatively and histologically assess the CaP hybridized human ST/G tendon grafts, we classified them into three groups according to their soaking time – number of soaking cycle: 30 sec – 20 cycles (Group A), 1 min – 15 cycles (Group B), 3 min – 5 cycles (Group C). The tendon grafts were divided into three parts: tibial end (TE), femoral end (FE) and intra-articular (IA) portion. TE was secured using the Krackow technique with No. 2 nonabsorbable sutures, and an Endobutton-CL (Smith & Nephew, USA) was passed through the looped FE, as performed clinically. Then, the IA portion was covered with the sleeve of a rubber glove to prevent CaP hybridization. More soaking cycles induced greater deposition of CaP in the tendon grafts when the total soaking time was the same. Covering the IA portion with a rubber sleeve prevented of CaP deposition. A large amount of CaP in TE was deposited because suture holes increased the total contact area with the solutions.
Authors: Hirotaka Mutsuzaki, Masataka Sakane, Yumi Katayoshi, Sinya Hattori, Hiromi Nakajima, M. Tanaka, Naoyuki Ochiai
Abstract: Calcium phosphate (CaP) hybridized to a whole tendon graft delayed cell repopulation in anterior cruciate ligament (ACL) reconstruction in rabbits. However, a tendon graft masked with an adhesive tape at the intra-articular (IA) portion to prevent CaP hybridization did not delay cell repopulation. Synovial tissues can adhere to the tendon graft and can invade the tendon graft masked at the IA portion. The masking induced an effect similar to that of the unhybridized tendon graft. The CaP hybridized tendon grafts masked at the IA portion showed cell repopulation 2 weeks earlier than the unmasked CaP hybridized tendon grafts.
Authors: Yu Sogo, Atsuo Ito, Hirotaka Mutsuzaki, Ayako Oyane, M. Onoguchi, Noboru Ichinose, Masataka Sakane, Naoyuki Ochiai
Abstract: A FGF-2-apatite composite layer (FGF-AP layer) was formed on the surface of Ti screws in a supersaturated calcium phosphate solution supplemented with FGF-2. By an in vitro study using fibroblastic NIH3T3 cells, it was confirmed that FGF-2 was immobilized in the layer without complete denaturation although the composite layer was formed at 37°C. When Ti screws with the FGF-AP layer were percutaneously implanted in the proximal tibial metaphysis of 16 rabbits, no osteomyelitis was observed in any rabbits although a FGF-2-free AP layer allowed osteomyelitis in some cases in our previous study. These results suggest that a FGF-AP layer formed on Ti screws is useful for resisting bacterial infection during external fixations.
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