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Anatomic Anteversion of the Acetabular Component Correlates with Polyethylene Linear Wear in Total Hip Arthroplasty: The Three-Dimensional Numerical Analysis

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Open Journal of Orthopedics 2016年第6期6卷 126-134页

作者： Ima Kosukegawa Satoshi Nagoya Mitsunori Kaya Mikito Sasaki Shunichiro Okazaki Daisuke Suzuki toshihiko yamashita Department of Orthopedic Surgery Sapporo Medical University Sapporo Japan Department of Musculoskeletal Biomechanics and Surgical Development Sapporo Medical University Sapporo Japan

Background: Although abduction of the acetabular component is considered to predict factors for polyethylene wear attributable to osteolysis, other radiographic factors have yet to be elucidated. The purpose of the present study was to evaluate whether anteversion or change in implantation angle of the acetabular component influences polyethylene linear wear by using standing and supine radiographs of the hip joint. Methods: Standing and supine plain anteroposterior radiographs of 62 hip joints in which cementless total hip arthroplasty was performed were examined for polyethylene linear wear rate (mm/year), pelvic inclination, and radiological inclination and anatomic anteversion of the acetabular component. Results: All correlation coefficients of measurements of polyethylene linear wear, pelvic inclination angle, anatomical anteversion angle and radiological inclination angle were calculated highly. And by the three-dimensional numerical analysis, anatomic anteversion of the acetabular component had at least some effect on the degree of polyethylene wear. Conclusion: This study suggests that increased anteversion of the acetabular component reduces polyethylene linear wear in metal-on-polyethylene total hiparthroplasty.

关键词： Total Hiparthroplasty Polyethylene Linear Wear Standing Position Settingangle of Acetabular Component

Biomechanical Stability of Open-Wedge High Tibial Osteotomy: Comparison of Two Locking Plates

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Open Journal of Orthopedics 2014年第10期4卷 257-262页

作者： Kota Watanabe Tomoaki Kamiya Daisuke Suzuki Hidenori Otsubo Atsushi Teramoto Tomoyuki Suzuki toshihiko yamashita Department of Physical Therapy Sapporo Medical University School of Health Science Sapporo Japan Department of Orthopaedic Surgery Sapporo Medical University School of Medicine Sapporo Japan Department of Musculoskeletal Biomechanics and Surgical Development Sapporo Medical University Sapporo Japan

Introduction: Recently, new plates with locking screws have been developed and used for medial open-wedge high tibial osteotomy (HTO). The purpose of this study was to evaluate and compare biomechanical properties of different internal fixations in open-wedge HTO using the two currently available locking plates. Methods: Eight paired fresh-frozen cadaveric lower extremities were vertically embedded in steel boxes. The axial compression load was applied to the legs using the mechanical testing machine. The axial compression load test from 0 N to 550 N and the failure test were performed before and after HTO. One side of the leg of a specimen was fixed with the Puddu locking plate and the other side was fixed with the TomoFix plate to compare the two plates using the same specimen. A mode of failure and vertical displacement of the medial and lateral parts of the tibia at the osteotomy gap was recorded using a video camera in the failure test. The load–displacement data were analyzed to calculate stiffness, failure load, and displacement at failure. Results: The mean failure load was 1471.4 N and 1692.3 N and total vertical displacement at failure was 3.1 mm and 2.9 mm with the Puddu and TomoFix plates, respectively. During axial compression loading, displacements mainly occurred at the lateral osteotomy gap, while the medial gap was well preserved. No significant differences were observed in the failure load, displacement, or mode of failure between the two plates. Conclusions: The Puddu and TomoFix plates had similar biomechanical properties in open-wedge HTO. The results indicated reliable stability after open-wedge HTO without fibular osteotomy.

关键词： High Tibial Osteotomy Puddu Plate TomoFix Cadaver Biomechanics

Clinical Features of Giant Cell Tumor of Bone in Elderly Patients

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Open Journal of Orthopedics 2021年第9期11卷 257-268页

作者： Hiroyuki Tsuchie Makoto Emori Hiroyuki Nagasawa Yasutaka Murahashi Emi Mizushima Junya Shimizu toshihiko yamashita Naohisa Miyakoshi Department of Orthopedic Surgery Akita University Graduate School of Medicine Hondo Japan Department of Orthopedic Surgery Sapporo Medical University School of Medicine Chūō-ku Japan

Background: Giant cell tumor of the bone (GCTB) occurs most often in younger individuals aged between 20 and 40 years. However, it also occurs in a small proportion of elderly people. Therefore, it is necessary to determine the clinical characteristics of GCTB in elderly people, as only few reports have completely examined the characteristics of GCTB in elderly patients. Methods: This retrospective study enrolled 69 patients with benign GCTB. Patients’ information on age, sex, anatomical location and size, Campanacci grade, pathological fracture, treatment for primary tumors, local and distant relapse, and outcome was collected. We compared these clinical courses between the younger and older groups. We divided the age groups into three subgroups: ≤54 years and ≥55 years, ≤59 years and ≥60 years, and ≤64 years and ≥65 years. We compared the two groups in each subgroup. In addition, we examined factors affecting local recurrence and distant metastasis. Results: Tumor size was significantly larger in the older group between the two subgroups of 55 and 60 years. Kaplan-Meier curves for local recurrence-free survival and distant metastasis-free survival between the two subgroups of 65 years showed significant differences (p = 0.0183 and p

关键词： Giant Cell Tumor Bone Elderly Local Recurrence

Analysis of Degenerative Discs in Lumbar Spondylolisthesis Using MRI T2 Mapping

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Open Journal of Radiology 2012年第3期2卷 77-80页

作者： Tsuneo Takebayashi Hiroyuki Takashima Mitsunori Yoshimoto Yoshinori Terashima Hajime Tsuda Kazunori Ida toshihiko yamashita Department of Orthopedic Surgery School of Medicine Sapporo Medical University Sapporo Japan

Background: Spinal instability, including lumbar degenerative spondylolisthesis (DS), mainly results from degeneration of intervertebral discs (IVD) and the facet joints (FJ). Characterization of the relationship between IVD degeneration in cases of lumbar degenerative spondylolisthesis (DS), and T2 values may be useful for accurate noninvasive evaluation and subsequent treatment. Thus, the goal of this study was to measure T2 values of IVDs in cases with (DS) and without (NS) spondylolisthesis, and to characterize changes of IVDs in DS. Methods: A total of 40 subjects who presented with L4 spondylolisthesis comprised the DS group. Another 40 subjects who did not have lumbar spondylolisthesis, constituted the NS group. T2 values of IVDs were measured and compared in these groups. Results: T2 values for IVDs tended to be lower in the DS group than in the NS group, and these values were significantly different (p < 0.01) within the anterior annulus fibrosus (AF). No significant differences in T2 values between Meyerding grades I and II were observed in any areas of IVDs. Conclusions: It is speculated that in the early stages, the degeneration of the anterior AF develops and is related to the onset of lumbar spondylolisthesis, while in later stages, degeneration of facet joints influences the progression of spondylolisthesis.

关键词： Degenerative Spondylolisthesis Intervertebral Disc T2 Mapping

BEHAVIOR OF MATERIALS DISCHARGED FROM THE ISHIKARI RIVER TO THE SEA IN THE SNOWMELT SEASON

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BEHAVIOR OF MATERIALS DISCHARGED FROM THE ISHIKARI RIVER TO ...

Superior Retinacular Artery Did Not Occlude in a Rat Model of the Non-Traumatic Osteonecrosis of the Femoral Head

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作者： toshihiko yamashita Tsuyoshi Suganuma Harukuni Tachibana Daisaku Saitou Shin-ichi Yamazaki Associate Professor Graduate School of Engineering Hokkaido University Kita 13 Nishi 8 SapporoHokkaido 060-8628 Japan Graduate Student Graduate School of Engineering Hokkaido University Associate Professor Graduate School of Engineering Hokkaido University Ishikari River Development and Construction Department Hokkaido Development Bureau Civil Engineering Research Institute of Hokkaido

＜正＞Field observations were performed at the basin and coastal sea area of the Ishikari River during the 2000 snowmelt flood. The concentrations of suspended solids （SS） and nutrients （nitrogen, phosphorus, etc.） in the river increase greatly with discharge. They can be roughly estimated from the discharge. When the river discharge increases, the concentrations of SS, nitrogen and phosphorus in the sea increase in the range up to 10 km or more from the river mouth. Materials supplied from the river repeat the process of precipitation, removal, and accumulation in the sea area more than 10 km from the estuary and influence the bottom sediment environment in the large sea area. The smaller is the grain size of the bottom sediment, the higher is the nutrient salt content.

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Open Journal of Orthopedics 2016年第6期6卷 144-149页

作者： Shunichiro Okazaki Satoshi Nagoya Junya Shimizu Nobuyuki Takahashi Keisuke Mizuo Hideki Hyodoh Kenji Tateda Ima Kosukegawa Satoshi Watanabe toshihiko yamashita Department of Musculoskeletal Biomechanics and Surgical Development Sapporo Medical University Sapporo Japan Department of Legal Medicine Sapporo Medical University Sapporo Japan Department of Orthopedic Surgery Sapporo Medical University Sapporo Japan

Non-traumatic osteonecrosis of the femoral head (ONFH) is believed to be avascular necrosis. Certainly, a disruption of a supplying artery induces necrosis in the supplying artery-dominant region. However, when an abnormality such as cell apoptosis, or another reason, is developed in the supplying artery-dominant region, it induces a disruption of the supplying artery. Therefore, to prove that ONFH is avascular necrosis, it is necessary to demonstrate the disruption of the supplying artery prior to histological osteonecrosis development. Here we investigate histologically, using a rat model, whether disruption of the supplying artery occurs before the initial development of ONFH following corticosteroid treatment. Rats were given imiquimod and methylprednisolone, and were sacrificed 1, 2, 3, 7 or 14 days after the last injection. At the sacrifice, the rat was perfused with 20 ml black Indian ink through the left ventricle. ONFH was observed in the Imiquimod + Methylprednisolone group at 7 and 14 days. The osteonecrotic area was not stained with perfused black Indian ink. However, the lateral portion of the femoral head near the superior retinacular artery was stained with the ink. In conclusion, the present study shows that the superior retinacular artery did not occlude before the initial development of ONFH histologically in rats.

关键词： Osteonecrosis of the Femoral Head Corticosteroid Rat Avascular

Stick–slip behavior of Indian gabbro as studied using a NIED large-scale biaxial friction apparatus

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Earthquake Science 2015年第2期28卷 97-118页

作者： Tetsuhiro Togo toshihiko Shimamoto Futoshi yamashita Eiichi Fukuyama Kazuo Mizoguchi Yumi Urata State Key Laboratory of Earthquake Dynamics Institute of Geology China Earthquake Administration Geological Survey of Japan AIST Tsukuba Central 7 National Research Institute for Earth Science and Disaster Prevention (NIED) Central Research Institute of Electric Power Industry

This paper reports stick-slip behaviors of Indian gabbro as studied using a new large-scale biaxial friction apparatus, built in the National Research Institute for Earth Science and Disaster Prevention （NIED）, Tsukuba, Japan. The apparatus consists of the existing shaking table as the shear-loading device up to 3,600 kN, the main frame for holding two large rectangular prismatic specimens with a sliding area of 0.75 m^2 and for applying normal stresses an up to 1.33 MPa, and a reaction force unit holding the stationary specimen to the ground. The shaking table can produce loading rates v up to 1.0 m/s, accelerations up to 9.4 m/s^2, and displacements d up to 0.44 m, using four servocontrolled actuators. We report results from eight preliminary experiments conducted with room humidity on the same gabbro specimens at v = 0.1-100 mm/s and an = 0.66-1.33 MPa, and with d of about 0.39 m. The peak and steady-state friction coefficients were about 0.8 and 0.6, respectively, consistent with the Byerlee friction. The axial force drop or shear stress drop during an abrupt slip is linearly proportional to the amount of displacement, and the slope of this rela- tionship determines the stiffness of the apparatus as 1.15 × 10^8 N/m or 153 MPa/m for the specimens we used. This low stiffness makes fault motion very unstable and the overshooting of shear stress to a negative value was recognized in some violent stick-slip events. An abrupt slip occurred in a constant rise time of 16-18 ms despite wide variation of the stress drop, and an average velocity during an abrupt slip is linearly proportional to the stress drop. The use of a large-scale shaking table has a great potential in increasing the slip rate and total displacement in biaxial friction experiments with large specimens.

关键词： Stick-slip in gabbro - Biaxial frictionapparatus - Shaking table Friction experiment Faultmechanics

Optical recordings reveal the differential distribution of glutamatergic transmission in the cochlear and vestibular nuclei in the newborn mouse brainstem

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Journal of Otology 2009年第2期4卷 106-114页

作者： Doi Tadashi Kaneko toshihiko Matsumoto Ayumi Asako Mikiya yamashita Toshio Department of Otolaryngology Kansai Medical University

Objective Using optical imaging in brainstem slices, we studied evoked responses in the mouse cochlear (CN) and vestibular (VN) nuclei. Methods The use of optical imaging allowed us to visualize the spatiotemporal patterns of excitatory propagation in the CN and VN. Optical recordings can differentiate excitatory propagation in the ventral CN(VCN) from that in the dorsal CN(DCN). Furthermore, we assessed the relative distribution of NMDA and non-NMDA receptors in these regions using the glutamate antagonists APV (NMDA receptor antagonist) and CNQX (non-NMDA receptor antagonist) in mouse brainstem slices during postnatal days 1 to 3. Results The average sensitivity to APV was 99.1% in the VCN, 76.0% in the DCN and 64.9% in the VN. The average sensitivity to CNQX was 0.9% in the VCN, 24.0% in the DCN and 35.1% in the VN. These results indicate that the effect of APV dominated in the VCN, while both APV and CNQX were effective antagonists in the DCN and VN. In the VN, the distribution of APV-and CNQX-sensitive cells was almost completely uniform. However, in the DCN the distribution of APV-and CNQX-sensitive cells was highly complex. The area that was more sensitive to CNQX was located in the superficial layer of the DCN while the area with a higher sensitivity to APV was located progressively in the deep layer. Conclusion This optical recording data suggests that there is a differential distribution of NMDA and non-NMDA receptor mediated neurotransmission in the VCN, DCN and VN.

关键词： voltage-sensitive dye NMDA non-NMDA photo diode array

Direct cholangioscopy combined with doubleballoon enteroscope-assisted endoscopic retrograde cholangiopancreatography

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World Journal of Gastroenterology 2012年第28期18卷 3765-3769页

作者： Tatsuya Koshitani Shogo Matsuda Koji Takai Takayuki Motoyoshi Makoto Nishikata Yasuhide yamashita toshihiko Kirishima Naomi Yoshinami Hiroyuki Shintani Toshikazu Yoshikawa Department of Gastroenterology Kyoto City Hospital Kyoto 6048845 Japan Department of Molecular Gastroenterology and Hepatology Kyoto Prefectural University of Medicine Graduate School of Medical Science Kyoto 6028566 Japan

Double-balloon enteroscope (DBE)-assisted endoscopic retrograde cholangiopancreatography (ERCP) is an effective endoscopic approach for pancreatobiliary disorders in patients with altered gastrointestinal anatomy. Endoscopic interventions via DBE in these postoperative settings remain difficult because of the lack of an elevator and the use of extra-long ERCP accessories. Here, we report the usefulness of direct cholangioscopy with an ultra-slim gastroscope during DBE-assisted ERCP. Three patients with choledocholithiasis in postoperative settings (two patients after Billroth Ⅱ gastrojejunostomy and one patient after Roux-en-Y gastrojejunostomy) were treated. DBE was used to gain access to the papilla under carbon dioxide insufflation, and endoscopic sphincterotomy was performed with a conventional sphincterotome. For direct cholangioscopy, the enteroscope was exchanged for an ultra-slim gastroscope through an incision in the overtube, which was inserted directly into the bile duct. Direct cholangioscopy was used to extract retained bile duct stones in two cases and to confirm the complete clearance of stones in one case. Bile duct stones were eliminated with a 5-Fr basket catheter under direct visual control. No adverse events were noted in any of the three cases. Direct cholangioscopy with an ultra-slim gastroscope facilitates subsequent treatment within the bile duct. This procedure represents another potential option during DBE-assisted ERCP.

关键词： Direct cholangioscopy Double-balloon enteroscope Endoscopic retrograde cholangiopancreatography