• Title/Summary/Keyword: Plate and screw

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The Use of Special Washers in Bone Plates for Improved Impact-Absorbing Characteristics (충격흡수 특성의 향상을 위하 내고정용 특수 와셔에 관한 연구)

  • 김윤영;김장수
    • Journal of Biomedical Engineering Research
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    • v.16 no.4
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    • pp.457-462
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    • 1995
  • Unlike the usual bone plate and screw fracture fixation, an improved plate fixation method, which can transfer gradually physiological load to bones, is described. The key feature of the present method is to use washers between the plate and the screw. Bio-absorbable materials or non-ferrous materials with good damping characteristics are used to manufacture the washers. The purpose of this paper is to discuss potential advantages of the proposed method, and to show experimentally its improved impact-absorbing characteristics. Vibration experiments are carried out for pig femurs and cow tibias with and without the proposed washers. This experiments show that the washers can drop the first peak value suite substantially in the FRF plots. Although in-vivo experiments have not been conducted, the present fixation method appears to be a simple and effective alternative to the presently used method.

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Applying tilt mechanism for high-resolution image acquisition (고해상도 영상 획득을 위한 틸트 메커니즘 적용 기법)

  • Song, Chun-Ho
    • Journal of the Korea Society of Computer and Information
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    • v.19 no.12
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    • pp.31-37
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    • 2014
  • In this paper, to compensate the degraded performance in high-resolution infrared sensor due to assembling error, the influence of each component was evaluated through the sensitivity analysis of lens assembly, axis mirror, and detector and also suggested detector tilt mechanism for compensation. 3 detector tilt mechanisms were investigated. The first one is 'Shim plate' method which is applying shim on installing plane. The second one is 'Tilting screw' method that is using tilt screw for adjusting detection plane. The last one is 'Micrometer head' method that is installing micrometer on detection plane and acquiring quantitative data. Based on the investigation result, 'Tilting screw' method was applied due to ease of user control, small volume, and real-time controllability, thereby we could acquire high-resolution infrared images. The research result shows that the tilting mechanism is necessary technology for the implementation of high-resolution infrared imaging system.

The Tangential Projection Method for Checking Existence and Nonexistence of Radius Groove Penetration of Screw after Distal Radius Fracture Operation Used the T-type Plate (T형 금속판을 이용한 요골 원위부 골절 수술 후 나사못의 요골구 관통 유무를 확인하기 위한 접선방향 촬영법)

  • Seo, Sun-Youl;Hong, Ki-Jang;Han, Man-Seok;Kim, Yong-Kyun
    • Journal of radiological science and technology
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    • v.33 no.4
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    • pp.335-340
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    • 2010
  • This paper is about a projection method to check existence of radius groove penetration of screw after distal radius fracture operation using the T-type plate. Angle of Radius groove was analyzed by fifty one CT images that contains patients' wrist and twenty cases of radius specimens. After making radius phantom by plaster, we set the screw so that it penetrated 2.4 mm depth of radius groove. Then, we projected the phantom by X-ray in change of the elevation and supination angle of distal radius by 5 degree interval on 0~30 degree. The average value of groove angle in the wrist CT images was 14.4 degree and the radius specimens was 16.3 degree. Screws penetrating radius groove of the phantom have different lengths according to elevation angle and supination angle. Consequently, in order to confirm existence and nonexistence of radius groove penetration of the screw in tangential projection after distal radius fracture operation using the T-type plate, we recommend 5 degree of elevation angle and 20 degree of supination angle.

MANUFACTURE AND CHARACTERISTICS OF SNACK-TYPE PRODUCTS CONTAINING MEAT AND STARCH

  • Cho, Soo-Hyun
    • Proceedings of the Korean Society for Food Science of Animal Resources Conference
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    • 1997.06a
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    • pp.19-39
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    • 1997
  • Extrusion conditions were optimized for blends of ground lamb and starch using a single-screw extruder for the purpose of producing expanded snack-type products. A central composite rotatable response surface methodology(RSM) design was used with variation in feed moisture, process temperature, and screw speed. The three variables significantly affected one or more of the measured physical properties of extrudates. The optimum conditions for minimum shear force values were 26.5% feed moisture, $148^{\circ}C$ process temperature, and 134 rpm screw speed. Lean ground beef, chicken, goat, lamb or mutton was blended with corn starch, and extruded at the optimum condition established from RSM experiments. Physical/rheological properties were generally similar, water activity was low (<0.12) and total aerobic plate counts were <10 for all products. Extrudates containing chicken had the highest ratio of polyunsaturated fatty acids to saturated fatty acids, whereas those containing beef had the highest ratio of monounsaturated fatty acids to saturated fatty acids. Sensory data indicated that texture was acceptable and flavor characteristics were not different among the products.

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Development of Devices of the Diversion Gate in Irrigation Canal (용수로 분수문 개폐장치 개발)

  • Jeon, Jong-Gil;Kim, Kyung-Won;Lee, In-Bok;Chun, Man-Bok
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2003.10a
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    • pp.223-226
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    • 2003
  • Devices of diversion gate used at irrigation canal, as a irrigation structures of agriculture, have shown serious problems such as corrosion, defect, inconvenience of operation, etc. Accordingly, handy devices of diversion gate have been developed and then tested in the laboratory. The operating types of the prototype were a rack-and-pinion type, an improved screw type that only gate plate was moved up and down while the screw axis was unmoved, and a remote control type which can be controlled from 50m away using a remote control system. Those 3 types were developed, and the improved screw type was shown the best operation through the laboratory tests.

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Delayed bladder perforation due to screw loosening after pelvic ring injury surgery: a case report

  • Shon, Hyun-Chul;Kang, Ho-Won;Lim, Eic-Ju;Yang, Jae-Young
    • Journal of Trauma and Injury
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    • v.35 no.1
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    • pp.51-55
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    • 2022
  • Pelvic ring injuries have high mortality and morbidity rates, and they are difficult to treat because accompanying injuries to the pelvic organs, genitourinary organs, and neurovascular tissues are common. Genitourinary injuries are common comorbid injuries that have been reported to occur in 5% to 6% of all pelvic ring injuries. However, these injuries usually occur simultaneously with the pelvic ring injury, whereas relatively little research has dealt with genitourinary injuries that occur after treatment of a pelvic ring injury. To the best of our knowledge, only three cases of delayed bladder perforation due to screw loosening after symphyseal plate fixation in anterior pelvic ring injury have been reported worldwide, and no such cases have yet been reported in Korea. Since the authors experienced this very rare complication after pelvic ring surgery, we report this case along with a literature review.

Cement Augmentation of Dynamic Hip Screw to Prevent Screw Cut Out in Osteoporotic Patients with Intertrochanteric Fractures: A Case Series

  • Rai, Avinash Kumar;Goel, Rajesh;Bhatia, Chirag;Singh, Sumer;Thalanki, Srikiran;Gondane, Ashwin
    • Hip & pelvis
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    • v.30 no.4
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    • pp.269-275
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    • 2018
  • Purpose: The purpose of this study is to describe a method of inserting cement in the femoral head before fixation with dynamic hip screw to prevent screw cut out due to osteoporosis and to evaluate its clinical outcome in these patients. Materials and Methods: In this prospective study, 30 patients aged 60 years and older with intertrochanteric fracture were included. Bone mineral density was measured. After reaming of the femoral head and neck with a triple reamer and polymethyl methacrylate, bone cement was introduced into the femoral head using a customized nozzle and a barrel fitted on a cement gun. A Richard screw was inserted and the plate was fixed over the femoral shaft. Patients were mobilized and clinical outcomes were rated using the Salvati and Wilson's scoring system. Results: More patients included in this study were between 66 and 70 years old than any other age group. The most common fracture according to the Orthopaedic Trauma Association classification was type 31A2.2 (46.7%). The T-score was found to be $-2.506{\pm}0.22$ (mean${\pm}$standard deviation); all patients were within the range of -2.0 to -2.8. The duration of radiological union was $13.67{\pm}1.77$ weeks. Salvati and Wilson's scoring at 12 months of follow up was $30.96{\pm}4.97$. The majority of patients were able to perform their normal routine activities; none experienced implant failure or screw cut out. Conclusion: Bone cement augmentation may effectively prevent osteoporosis-related hardware complications like screw cut out in elderly patients experiencing intertrochanteric fractures.

Optimization of Screw Pumping System (SPS) for Mass Production of Entrapped Bifidus

  • Ryu, Ji-Sung;Lee, Yoon-Jong;Choi, Soo-Im;Lee, Jae-Won;Heo, Tae-Ryeon
    • Food Science and Biotechnology
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    • v.14 no.5
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    • pp.566-571
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    • 2005
  • Process of screw-pumping system (SPS) was optimized for mass production of encapsulated bifidus. SPS entrapment device was composed of feeding component, with optimized nozzle size and length of 18G (0.91 cm) and 4 mm, respectively, screw pump, and 37-multi-nozzle. Screw component had five wing turns [radius (r)=26 to 15 mm] from top to bottom of axis at 78-degree angle from middle of the screw, and two wings were positioned at screw edge to push materials toward nozzle. For nozzle component, 37 nozzles were attached to 20-mm round plate. Air compressor was attached to SPS to increase productivity of encapsulated bifidus. This system could be operated with highly viscous (more than 300 cp) materials, and productivity was higher than $1128\;{\pm}\;30\;beads/min$. Viability of encapsulated bifidus was $5.45\;{\times}\;10^8\;cfu$/bead, which is superior to that of encapsulated bifidus produced by other methods ($2.51{\times}10^8\;cfu$/bead). Average diameter of produced beads was $2.048\;{\pm}\;0.003\;mm$. Survival rate of SPS-produced encapsulated bifidus was 90% for Simulator of the Human Intestinal Microbial Ecosystem test and 88% in fermented milk (for 14 days). These results show SPS is effective for use in development of economical system for mass production of viable encapsulated bifidus.

Ultrasonographic Diagnosis of Extensor Tenosynovitis Caused by Dorsal Screw Prominence after Volar Plate Fixation of Distal Radius Fracture: Case Report (원위 요골 골절의 수장측 금속판 고정술 후 발생한 신전건 활막염에 대한 초음파를 이용한 진단: 증례 보고)

  • Lim, Tae Kang;Kim, Sang Yeol;Kang, Hong Je;Hah, Dae Ho
    • The Journal of Korean Orthopaedic Ultrasound Society
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    • v.6 no.2
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    • pp.60-64
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    • 2013
  • After volar locking plating of distal radius fracture, complications arising from unrecognized dorsally prominent screws penetrating the extensor compartments are increasingly reported. However, standard radiography and fluoroscopy may not adequately visualize screw lengths, because of complex shape of dorsal cortex of the distal radius. We presented case of ultrasonography diagnosis of extensor tenosynovitis caused by dorsal screw prominence after volar plate fixation of distal radius fracture.

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Open Reduction of Proximal Interphalangeal Fracture-Dislocation through a Midlateral Incision Using Absorbable Suture Materials

  • Lee, Jae Jun;Park, Hyoung Joon;Choi, Hyun Gon;Shin, Dong Hyeok;Uhm, Ki Il
    • Archives of Plastic Surgery
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    • v.40 no.4
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    • pp.397-402
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    • 2013
  • Background Fracture-dislocation of the proximal interphalangeal (PIP) joint is a relatively common injury. Various treatments for fracture-dislocation of the PIP joint have been reported. In the present study, we performed open reduction through a midlateral incision using absorbable sutures to reduce the small bone fragments and performed volar plate repair. Methods We treated nine patients with fracture-dislocation of the PIP joint with small fractured bone fragments too small for pinning or screw fixation. Patients with volar plate injury were treated with open reduction and volar plate repair at the periosteum of the middle phalangeal bone base by the modified Kessler method using absorbable sutures. All patients were placed in a dorsal aluminum extension block splint, which maintained the PIP joint in approximately 30 degrees of flexion to avoid excessive tension on the sutured volar plate. Results At a mean final follow-up of postoperative 9 months, all patients were evaluated radiographically and had adequate alignment of the PIP joint and reduction of the displaced bone fragments. Range of motion was improved and there were no complications. Conclusions This technique is an excellent alternative to the current method of treating patients with fracture-dislocations that include small fragments that are too small for pinning or screw fixation. It is a less invasive surgical method and enables stable reduction and early exercise without noticeable complications.