Faculty Profiles - OZAKI Toshifumi

Posterior spinal fusion using a pedicle nail system with polymethylmethacrylate in a paraplegic patient after vertebral collapse caused by osteoporosis Reviewed

Yoshihisa Sugimoto, Masato Tanaka, Hitoshi Konishi, Tomoyuki Takigawa, Kazuo Nakanishi, Haruo Misawa, Yasuo Ito, Toshifumi Ozaki

Spine Journal 9 ( 1 ) -e8 2009.1

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

Background context: Because posterior decompression and fusion for vertebral collapse in an osteoporotic spine sometimes results in a pullout of the pedicle screw. Several authors reported that fixation of pedicle screws in severely osteoporotic bone could be improved by inserting polymethylmethacrylate (PMMA) into the hole before inserting the screw. However, pedicle screws were not designed to be used with PMMA. Purpose: To report a patient with vertebral collapse who were treated using a novel-concept, pedicle nail using with PMMA. Study design: Case report. Methods: The patient was a 74-year-old female who experienced back pain after some heavy lifting 3 months before. She was laid up for 2 months because of the back pain and weakness of her lower legs. Radiographs and magnetic resonance imaging showed vertebral collapse and neural severe compression from the posterior wall of vertebra T12. The pedicle nail consists of an outer sheath with evenly spaced holes and an internal, removable, threaded component. The outer sheath and the internal component were connected before insertion. The pedicle nail attaches to and is bound by the PMMA through the holes of the outer sheath. We performed a T11-L1 posterior fusion and laminectomy using the pedicle nail, and we used a hydroxyapatite block to perform a transpedicular vertebroplasty of T12. Results: Bone union was observed on a lateral radiograph without pedicle nail loosening. Conclusions: The authors speculate that posterior spinal fusion and vertebroplasty using the pedicle nail will be a reasonable choice for delayed paraplegia after osteoporotic vertebral fracture. © 2009 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.spinee.2007.10.036

PubMed

Cutting Tool Protects for Soft Tissues in Bone-Milling Machining. Reviewed

Naohiko Sugita, Taiga Nakano, Takayuki Osa, Yoshikazu Nakajima, Kazuo Fujiwara, Nobuhiro Abe, Toshifumi Ozaki, Masahiko Suzuki, Mamoru Mitsuishi

IJAT 3 ( 2 ) 185 - 192 2009

Publishing type：Research paper (scientific journal) Publisher：Fuji Technology Press Ltd.

Minimally invasive orthopedic surgery using a milling machine presents challenges. The milling machine we developed has a redundant axis to minimize cutting-tool contact with surrounding soft tissue. Important components are modeled based on physical requirements, and model-based geometric optimization improves performance. Here we discuss the protective mechanism, hardware, and software we developed to cover the nonworking cutting-edge portion and to protect against soft-tissue damage. We evaluated the effectiveness of this approach using cadaveric bone.

DOI： 10.20965/ijat.2009.p0185

Interference Free Tool Path Generation in Multi-Axis Milling Machine for Orthopedic Surgery. Reviewed

Taiga Nakano, Naohiko Sugita, Takeharu Kato, Kazuo Fujiwara, Nobuhiro Abe, Toshifumi Ozaki, Masahiko Suzuki, Mamoru Mitsuishi

IJAT 3 ( 5 ) 514 - 522 2009

Publishing type：Research paper (scientific journal) Publisher：Fuji Technology Press Ltd.

Tool interference causes serious damage to surrounding soft tissue in minimally invasive orthopedic surgery with a milling robot. The objective of this study is to avoid the collision of cutting tool with complicated shapes, and a novel approach of interference-free toolpath generation in a short intraoperative time is proposed. In order to resolve this issue, we propose the following two methods: intraoperative modeling of soft tissues as an interference area and interference-free toolpath generation based on the model. A model is constructed to represent the opening area and the internal tissues by using a 3-dimensional optical position sensor to measure them. Based on the constructed model, interference-free toolpath is immediately determined by the preliminary definition of evacuating direction. The effectiveness of the proposed method is evaluated with artificial models on the system that the authors have developed so far. A tool contact force against the model was measured by a force sensor mounted on the cutting tool. The result revealed that the tool interference was greatly reduced by implementing the proposed method.

DOI： 10.20965/ijat.2009.p0514

Tool path generation to protect soft tissue with multi-axis milling machine Reviewed

Nakano T, Sugita N, Nakajima Y, Kato T, Fujiwara K, Abe N, Ozaki T, Suzuki M, Mitsuishi M

Proceedings of the 5th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2009 2009

Publishing type：Research paper (international conference proceedings)

Tool interference causes damage to surrounding soft tissue in minimally invasive orthopedic surgery with a milling robot. The objective of this study is to avoid the collision of cutting tool with complicated shapes, and a novel approach of interference-free tool path generation is proposed: intraoperative modeling of tissues and interference-free tool path generation. A model is constructed by using a 3-dimensional optical position sensor. Based on the model, interference-free tool path is immediately determined by preliminary definition of evacuating direction. The effectiveness of the proposed method is evaluated with artificial models on the system that we have developed so far.

Other Link： http://orcid.org/0000-0002-1369-0747

Dynamic controlled milling process for bone machining Reviewed

Sugita N, Nakano T, Nakajima Y, Fujiwara K, Abe N, Ozaki T, Suzuki M, Mitsuishi M

Journal of Materials Processing Technology 209 ( 17 ) 5777 - 5784 2009

Publishing type：Research paper (scientific journal)

Optimal control of the machining process in orthopedic surgery can not only increase productivity but also ensure safety during tool usage. The authors have developed a technology for a force control system. The system has two modes of operation: the "air-cutting mode" and the "force control mode." In the air-cutting mode, tool feed is scheduled by predicting the air and bone-cutting zones from the CAD/CAM system. In the force control mode, the software monitors the cutting force and the cutting temperature, and it controls the feed override according to the difference between the real and the desired cutting force. The software is installed on a robot controller, and its effectiveness is evaluated with a urethane bone. © 2009 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jmatprotec.2009.06.008

Other Link： http://orcid.org/0000-0002-1369-0747

A Case of Stem Fracture Following Bipolar Head Prosthesis

Minagawa Hiroshi, Mitani Shigeru, Endo Hirosuke, Tetsunaga Tomonori, Ozaki Toshifumi, Fujiwara Kazuo

The Journal of the Chugoku-Shikoku Orthopaedic Association 21 ( 1 ) 83 - 88 2009

Language：Japanese Publisher：The Chugoku-Shikoku Orthopaedic Association

Cases of a fracture of the hydroxyapatite (HA)-coated stem in patients who underwent total hip arthroplasty have occasionally been reported. This article describes a case of stem fracture seen in a 61-year-old female patient more than 11 years after cementless bipolar head prostheses performed at this hospital. The patient had idiopathic avascular necrosis of the right femoral head, and at the age of 48, she underwent cementless bipolar head prosthesis using a titanium, HA-coated MCF stem (Kyocera Corporation, Kyoto, Japan). The stem was successfully implanted, and the postoperative clinical progress was uneventful. Eleven years and 10 months after operation, the patient had acute weakness of the right hip when she stood up, resulting in gait disturbance. Hip radiography revealed a fracture of the basal portion of the stem neck, and a revision hip arthroplasty was performed. Analysis showed that the fracture developed from the site of a rectangular notch serving as a gripper made at the stem neck. Therefore, the fracture might be caused by stress concentration at the rectangular part and the resultant metal fatigue. Implants with such design may be associated with breakage even a long time after bipolar head prostheseis.

DOI： 10.11360/jcsoa.21.83

CiNii Article

Growth suppression and apoptosis induction in synovial sarcoma cell lines by a novel NF-κB inhibitor, dehydroxymethylepoxyquinomicin (DHMEQ) Reviewed

Keisuke Horiuchi, Hideo Morioka, Kazumasa Nishimoto, Yoshihisa Suzuki, Michiro Susa, Robert Nakayama, Akira Kawai, Hiroshi Sonobe, Hironari Takaishi, Toshifumi Ozaki, Hiroo Yabe, Kazuo Umezawa, Yoshiaki Toyama

Cancer Letters 272 ( 2 ) 336 - 344 2008.12

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

Synovial sarcoma is a relatively common soft tissue sarcoma with an aggressive clinical course. Although surgery is currently the first treatment modality, improvement of adjuvant chemotherapy is deemed essential to improve the clinical outcome. Nuclear factor-κB (NF-κB) is constitutively activated in various cancer cells and has emerged as a potential therapeutic molecular target
however, the possible involvement of NF-κB in the pathology of sarcomas remains to be clarified. Herein we examined the effects of a novel NF-κB inhibitor, dehydroxymethylepoxyquinomicin (DHMEQ) on two synovial sarcoma-derived cell lines, HS-SY-II and SYO-1. The growth of both cell lines was completely inhibited by DHMEQ and apoptosis was induced at 10 μg/ml. Additionally, we found that DHMEQ showed additive effects when used in combination with other cytotoxic agents. These observations indicate that inhibition of NF-κB activity may serve as a potential therapeutic target for synovial sarcoma. © 2008 Elsevier Ireland Ltd. All rights reserved.

DOI： 10.1016/j.canlet.2008.07.021

PubMed

Isolation of a mRNA Preferentially Expressed in Synoviocytes from Rheumatoid Arthritis That is Identical with Lumican, which Encodes a Collagen Binding, Extracellular Matrix Protein Reviewed

Hiroki Mori, Keiichiro Nishida, Toshifumi Ozaki, Hajime Inoue, Tohru Nakanishi

JOURNAL OF HARD TISSUE BIOLOGY 17 ( 3 ) 125 - 130 2008.12

Language：English Publishing type：Research paper (scientific journal) Publisher：JOURNAL HARD TISSUE BIOLOGY

Rheumatoid arthritis (RA) is a complex disease including autoimmune disorder and resulting in inflammation. It also shows progressive proliferation of synoviocytes, and these synoviocytes destroys articular structure. In order to understand the mechanism of this abnormal proliferation of RA-originated synoviocytes in molecular level, we analyzed the gene expression profiles by using DNA chips that contain more than 10,000 genes. Comparing the expression profiles of normal and RA-originated synoviocytes, we found several genes that are highly expressed in RA-originated synoviocytes than normal synoviocytes. Among these genes, we focused on one hypothetical protein, cDNA of which contains one reading frame in its DNA fragment, indicating that this fragment is a part of large mRNA structure. The expression of this gene in RA-originated synoviocytes is about three times higher than that in normal synoviocytes by DNA chip analysis. After cDNA cloning of this mRNA, we found that the gene is identical with lumican, which encodes a collagen binding, extracellular matrix protein. This mRNA was widely distributed in many tissues but its alternatively spliced forms are differently expressed in various tissues.

CentPillar GB HA stemの短期成績

鉄永智紀, 三谷茂, 藤原一夫, 遠藤裕介, 皆川寛, 尾崎敏文

日本人工関節学会誌 38 522 - 523 2008.12

下肢人工関節置換術後の静脈血栓症の予防に対するアリクストラ(Fondaparinux Sodium)の使用経験

皆川寛, 三谷茂, 阿部信寛, 遠藤裕介, 鉄永智紀, 藤原一夫, 尾崎敏文

日本人工関節学会誌 38 652 - 653 2008.12

SAPHO syndrome associated spondylitis Reviewed

Tomoyuki Takigawa, Masato Tanaka, Kazuo Nakanishi, Haruo Misawa, Yoshihisa Sugimoto, Tomohiro Takahata, Hiroyuki Nakahara, Shinnosuke Nakahara, Toshifumi Ozaki

EUROPEAN SPINE JOURNAL 17 ( 10 ) 1391 - 1397 2008.10

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

The concept of synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome has been well clarified, after Chamot et al. suggested this peculiar disorder in 1987. The most commonly affected site in SAPHO syndrome is the anterior chest, followed by the spine. However, the clinical course and taxonomic concept of SAPHO spinal lesions are poorly understood. This study was performed to analyze: (1) the detailed clinical course of spinal lesions in SAPHO syndrome, and (2) the relationship between SAPHO syndrome with spinal lesions and seronegative spondyloarthropathy. Thirteen patients with spondylitis in SAPHO syndrome were analyzed. The features of spinal lesions were a chronic onset with a slight inflammatory reaction, and slowly progressing non-marginal syndesmophytes at multi spinal levels, besides the coexistence of specific skin lesions. SAPHO syndrome, especially spinal lesions related to palmoplantar pustulosis, can be recognized as a subtype of seronegative spondyloarthropathy.

DOI： 10.1007/s00586-008-0722-x

SAPHO syndrome with rapidly progressing destructive spondylitis: two cases treated surgically Reviewed

Tomoyuki Takigawa, Masato Tanaka, Shinnosuke Nakahara, Yoshihisa Sugimoto, Toshifumi Ozaki

EUROPEAN SPINE JOURNAL 17 S331 - S337 2008.9

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

The authors present two cases of synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome with rapidly progressing destructive spondylitis treated surgically. The spinal lesions in SAPHO syndrome generally have a good prognosis and rarely cause the structural destruction or neurological deterioration. Case 1: a 63-year-old female had palmoplantar pustulosis for 2 years. At first, she only felt a pain in the nape with no inducing factor. Two months later, she had incomplete quadriplegia (ASIA scale C). Magnetic resonance imaging showed destruction of C4-C7, kyphotic deformity, and severe compression of the spinal cord. Decompression and reconstruction surgery using anterior and posterior approach improved her paralysis. Case 2: a 69-year-old female complained of persistent back pain. Magnetic resonance imaging revealed spondylitis of T7-T9. Although there were no typical skin lesions, we diagnosed SAPHO syndrome by hyperostosis of the stemocostoclavicular joint and sacral joint. Destruction with kyphotic deformity of the spine progressed gradually for 3 months. Curettage and reconstruction surgery using thoracic endoscope relieved her pain and prevented the destruction of the spine. The histopathology of the specimen obtained surgically showed non-specific inflammation in both cases. Spondylitis in SAPHO syndrome may cause severe destruction and kyphotic deformity followed by paralysis.

DOI： 10.1007/s00586-008-0663-4