• 제목/요약/키워드: bone strength

검색결과 499건 처리시간 0.024초

관절경적 회전근 개 봉합술: 이열 봉합술 및 교량형 봉합술식 (Arthroscopic Rotator Cuff Repair: Double Rows & Suture Bridge Technique)

  • 신상진
    • Clinics in Shoulder and Elbow
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    • 제11권2호
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    • pp.82-89
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    • 2008
  • 이상적인 회전근 개 봉합술은 봉합 초기 높은 고정 강도로 봉합 부위 건-골간 간격 형성을 최소화시키며, 재활 과정 중 발생하는 반복적인 부하에도 견디는 기계적 강도를 나타내어 궁극적으로 건-골 조직의 생물학적 치유를 얻을 수 있는 방법이다. 현재 사용되는 회전근 개 봉합술 중 교량형 봉합술식은 회전근 개 부착 부위를 해부학적으로 복원할 수 있으며, 건-골간 압력 접촉 면적을 증가시키고, 방사형의 봉합 형태를 통하여 회전근 개 전체에 균등하게 압력을 분포함으로 부하를 분산시키며 생물학적 치유를 향상시킨다. 또한 건-골간 간격 형성을 최소화하며 전단 및 회전 응력에 저항력을 주어 정상과 동일한 해부학적 복원력으로 빠른 재활 운동을 가능하게 한다. 그러나 비록 교량형 봉합술식이 다른 술식에 비해 우수한 생역학적 특성을 나타내도 임상적으로 더 좋은 결과를 초래한다는 증거는 없으며, 이열 봉합술과는 비슷한 재파열율이 보고되고 있다. 회전근 개봉합술의 선택은 회전근 개 파열 크기, 파열 양상 및 건의 상태 등을 고려하여 적절하게 선택하여야 할 것으로 사료된다.

하악 우각부 축소를 위한 골절제술의 체계적 고찰 및 증례 보고 (OSTECTOMIES FOR MANDIBULAR ANGLE REDUCTION: A SYSTEMATIC REVIEW AND A REPORT OF CASES)

  • 박준우;최진영;김형욱;김종식;정인원;강진한;홍순민
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제29권4호
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    • pp.340-352
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    • 2007
  • In this systematic review on bone reduction procedures for the correction of the prominent mandibular angle, we collected and sorted the methods. The strength and weakness, indication, complication, and final esthetic result of each method were evaluated. After searching and filtering the literatures on the base of inclusion criteria, 9 eligible case series studies were included in this study. There were 3 types of curved ostectomies and 4 types of lateral cortical ostectomies. Surgical procedures for curved ostectomies were divided into 2 types. One was single curved ostectomy and the other was multistaged curved ostectomy. Lateral cortical ostectomies reported were all similar to sagittal split ramus osteotomy. The complications reported in the included studies were scarce, but curved ostectomies may be able to induce many complications. The prominent mandibular angle must be analyzed in the lateral dimension and frontal dimension, and curved ostectomy can reduce the mandibular angle laterally while lateral cortical ostectomy can reduce the bigonial distance frontally. Because curved ostectomies can induce complications and unnaturally large mandibular angle while can not reduce bigonial distance efficiently, the current trend for the angle reduction procedure is lateral cortical ostectomies.

조기 이유한 흰쥐에서 유단백질의 섭취수준과 조성비가 기관성장과 단백질대사에 미치는 영향 (Effects of Milk Protein levels and Casein/Whey Ratios on Organ Growth and Protein Metabolism in Early Weaned Rats)

  • 박미나
    • Journal of Nutrition and Health
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    • 제30권1호
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    • pp.3-11
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    • 1997
  • This study was conducted to investigate the effects of protein levels and casein/whey ratios on organ growth and protein metabolism in early weaned rats. Premature rats weaned by the 17th day were fed six semipurified synthetic, isocaloric and gel diets that contained three levels (low, medium and high) and two different combinations(casein/whey ; 80 : 20 or 20 : 80) of milk protein for 8 days. On the 25th day postpartum, frest weigth and DNA, RNA and milk protein contents in brain, liver, kidney and muscle were determined to ascertain organ and cellular growth. Futher, with a view to ascertain protein metabolism and renal functions, serum total protein, $\alpha$-amino N, urea N, and creatinine and creatinine and urinary urea N, creatinine and hydroxproline were determined. Total DNA contents of brain, liver and kidney, which may represent as an index of cell numbers in those organs were significantly decreased in the rats fed diets containing low level protein regardless of casein/whey ratio. However, as fat as the rats fed high protein diets were concerned, their fresh weight, protein contents and GFR of kidney were significantly increased. Furthermore, nitrogen components, $\alpha$-amino N, urea N and creatinie in serum and urine were also increassed. Another observation was that high casein/whey ratio significantly facilitated accumulation of porteins in muscle and kidney and urinary hydorxyproline excretion, not affecting the DNA content of those organs. This study showed that low(8%) or high(32%) contents of protein had less desirable effects either on protein metabolism or on organ cellular growth in prematurely weaned rats, whereas there were no effects on general growth and bone strength.

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Absorbable Plate as a Perpendicular Strut for Acute Saddle Nose Deformities

  • Kim, Jong-Gyu;Rhee, Seung-Chul;Cho, Pil-Dong;Kim, Deok-Jung;Lee, Soo-Hyang
    • Archives of Plastic Surgery
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    • 제39권2호
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    • pp.113-117
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    • 2012
  • Background : Nasal pyramid fractures accompanied by saddle nose deformities are not easily corrected by closed reduction. We used an absorbable plate as a perpendicular strut to support the collapsed "keystone area" and obtained good results. Methods : Between September 2008 and June 2011, 18 patients who had nasal pyramid fractures with saddle nose deformities underwent surgery. Pre- and postoperative facial computed tomographic images and photographs were taken to estimate outcomes. The operative technique included the mucoperichondrial dissection of the nasal septum, insertion of an absorbable plate prepared to an appropriate length to support the "keystone area", and fixation of the absorbable plate strut to the cartilaginous septum. Results : Functional and esthetic outcomes were satisfactory in all patients. Eleven patients assessed the postoperative appearance of the external nose as 'markedly improved' and 7 patients as 'improved'. The 5 surgeons scored the results as a mean of 4.5 on a 5-point scale. Conclusions : The use of an absorbable plate as a perpendicular strut requires no additional procedures because the plate is gradually absorbed. The mechanical strength provided by a buttress between the "keystone area" and the maxillary crest lasts for a long time before the strut is absorbed.

여성이 경험한 폐경의 의미 (The Meaning of Menopause Experienced by Women)

  • 김애경;유은광
    • 여성건강간호학회지
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    • 제3권1호
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    • pp.82-92
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    • 1997
  • The purpose of this study was attempted to understand the substance and meaning of menopause experienced by women through informal interviews with oral consent. The informants were 6 perimenopausal women of 50-55 years old who are executing menopause. Colaizz's analytical method, a type of phenomenological analysis, was used to analyze data recorded by audiotape. One professor and a master's degree student who understand phenomenology, and the one who has a master of arts examined the validity between the meanings composed of the clusters of themes. Findings were turned out to be valid through validation process as the last step. The meaning of menopause implied both 'concept about menopause' and 'menopause as a time of change'. Menopause was mostly considered as cessation of menstruation as a physiological, natural, and normal process by aging. However, some people regarded menopause as a loss of youth and womanhood and lessening of every function of the body. Menopause as the time of changes means 'the period of' 'hormonal changes' such as change of menstruation, hot flushes, perspiration, and palpitation ; 'body function changes' of visual acuity, physical strength, sleeping, digestion, thoughts, bone and joints, skin sensibility, sexual pattern and intelligence ; 'emotional changes' such as anxiety, loneliness, gloominess, and nervousness. Menopause is a turning point on the women's life cycle accompanying various kind of changes and health problems. Therefore it is inevitable to develop strategy helping menopausal women pass through the critical successfully by adapting and coping with their critical period toward the healthy and better quality of life individually rather than putting them all into the standardized hormonal replacement protocol.

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슬관절 전방 십자 인대 재건술 후 발생한 이식 건의 일과성 석회화 - 증례 보고 - (Transient Calcification of Autogenous Grafted Patellar Tendon in Anterior Cruciate Ligament Reconstruction - A Case Report -)

  • 정현기;최충혁;김종헌;김재영
    • 대한관절경학회지
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    • 제3권1호
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    • pp.30-34
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    • 1999
  • 30세의 남자환자로 자가 슬개골 건을 이용한 전방 십자 인대 재건술 후 이식건에 발생한 일과성 석회화 1례를 보고 하고자 한다. 환자는 양측 절개술의 관절경하 전방 십자 인대 재건술을 시행 받았으며 술 후 6개월 방사선 필름 상, 이식 건 주위로 석회화 음영이 나타났으며 술 후 13개월 석회화 음영이 사라졌다. 술 후 2개월 Lachman 검사와 pivot shift 검사에서 음성을 보였으며. KT-1000 Arthrometer 검사 상 20 Ibs에서 건측과 1mm의 차이를 보였으나, 술 후 6개월에 이식 건 주위로 석회화 음영이 나타났을 때는 경도의 전방 불안정성이 관찰되었으며, 이후 석회화 음영이 없어지면서 슬관절의 전방 불안정도 회복되었다.

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임상가를 위한 특집 2 - 티타늄 임플란트 표면처리에서의 나노테크놀로지 (Nanotechnology in the Surface Treatment of Titanium Implant.)

  • 오승한
    • 대한치과의사협회지
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    • 제48권2호
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    • pp.106-112
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    • 2010
  • 아직까지 나노관련 기술이 티타늄 임플란트에 직접적으로 사용되는 부분이 상당히 미약하다. 하지만, 수직으로 정렬된 구조를 가지는 티타니아 나노튜브는 생체 내 대부분의 임플란트 재료로 사용되는 티타늄의 차세대 개발에 있어서 가장 중요한 영향을 미칠 것이다. 본문에 설명되어 있는 내용들 뿐 만이라, 티타니아 나노튜브는 파골세포의 골 흡수성 방지, 줄기세포의 특정 성체세포로의 분화, 연골세포의 재분화, 간세포를 이용한 생물 반응기(bio-reactor) 개발 등 생체재료의 여러 분야에서 많이 연구되고 있다. 특히, 줄기세포에 관한 연구는 차세대 임플란트 개발에 있어서 가장 중요한 연구 분야 중의 하나로서, 골을 형성하는 조골세포와 골을 파괴하는 피골세포 모두 줄기세포 로부터 만들어진다는 것을 유념해야 할 것이다. 만약, 티타니아 나노튜브의 독특한 나노구조를 이용하여 줄기세포의 조골세포로의 직접 분회를 제어하는 기술이 개발되어 상업화된다면, 이 기술을 기반으로 하여 현 재까지 개발된 모든 표면 증착 및 코팅 기술을 새롭게 이용하는 차세대 티타늄 임플란트의 개발을 위한 초석이 되리라고 본다.

슬괵건을 이용한 전방십자인대 재건술시 횡고정 핀과 간섭나사를 이용한 대퇴터널 고정술 -수술 수기- (Cross-Pin and Interference Screw Femoral Fixation in Anterior Cruciate Ligament Reconstruction using Hamstring Tendon -Technical Note-)

  • 인용;박원종;박종범;홍승환
    • 대한관절경학회지
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    • 제6권1호
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    • pp.60-63
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    • 2002
  • 목적 : 네 겹의 슬괵건을 이용한 전방십자인대 재건술시 대퇴터널을 횡고정 핀과 흡수성 간섭나사로 함께 고정하는 수기를 소개하고자 한다. 수술 술기 : 반건양건과 박건을 채취하여 네 겹으로 준비하였다. 경골터널과 대퇴터널을 만드는데 대퇴터널의 깊이는 35 mm로 하였다. Rigidfix system의 가이드를 삽입하고 가이드의 위쪽 관에만 구멍을 내었다. 이식건을 통과시킨후 횡고정 핀 을 고정하였다. 이후 이식건을 경골쪽으로 당기면서 흡수성 간섭 나사로 고정하였다. 결론 : 슬괵건 전방십자인대 재건술시 횡고정 핀과 흡수성 간섭나사를 이용한 대퇴터널 고정은 강한 초기 고정과 이식건의 골통합을 촉진시킬 수 있는 좋은 방법으로 사료되어 소개하였다.

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Saw-tooth softening/stiffening - a stable computational procedure for RC structures

  • Rots, Jan G.;Invernizzi, Stefano;Belletti, Beatrice
    • Computers and Concrete
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    • 제3권4호
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    • pp.213-233
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    • 2006
  • Over the past years techniques for non-linear analysis have been enhanced significantly via improved solution procedures, extended finite element techniques and increased robustness of constitutive models. Nevertheless, problems remain, especially for real world structures of softening materials like concrete. The softening gives negative stiffness and risk of bifurcations due to multiple cracks that compete to survive. Incremental-iterative techniques have difficulties in selecting and handling the local peaks and snap-backs. In this contribution, an alternative method is proposed. The softening diagram of negative slope is replaced by a saw-tooth diagram of positive slopes. The incremental-iterative Newton method is replaced by a series of linear analyses using a special scaling technique with subsequent stiffness/strength reduction per critical element. It is shown that this event-by-event strategy is robust and reliable. First, the model is shown to be objective with respect to mesh refinement. Next, the example of a large-scale dog-bone specimen in direct tension is analyzed using an isotropic version of the saw-tooth model. The model is capable of automatically providing the snap-back response. Subsequently, the saw-tooth model is extended to include anisotropy for fixed crack directions to accommodate both tensile cracking and compression strut action for reinforced concrete. Three different reinforced concrete structures are analyzed, a tension-pull specimen, a slender beam and a slab. In all cases, the model naturally provides the local peaks and snap-backs associated with the subsequent development of primary cracks starting from the rebar. The secant saw-tooth stiffness is always positive and the analysis always 'converges'. Bifurcations are prevented due to the scaling technique.

Effect of Milling Time on Pore Size and Distribution of Ti-Nb-Zr Biomaterials with Space Holder Consolidated by Spark Plasma Sintering

  • Kim, Dong-Gun;Woo, Kee-Do;Kang, Dong-Soo;Lee, Tack
    • 한국재료학회지
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    • 제24권2호
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    • pp.111-115
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    • 2014
  • Titanium and its alloys are useful for implant materials. In this study, porous Ti-Nb-Zr biomaterials were successfully synthesized by powder metallurgy using a $NH_4HCO_3$ as space holder and $TiH_2$ as foaming agent. Consolidation of powder was accomplished by spark plasma sintering process(SPS) at $850^{\circ}C$ under 30 MPa condition. The effect of high energy milling time on pore size and distribution in Ti-Nb-Zr alloys with space holder($NH_4HCO_3$) was investigated by optical microscope(OM), scanning electron microscope(SEM) & energy dispersive spectroscopy(EDS) and X-ray diffraction(XRD). Microstructure observation revealed that, a lot of pores were uniformly distributed in the Ti-Nb-Zr alloys as size of about $30-100{\mu}m$ using mixed powder and milled powders. In addition, the pore ratio was found to be about 5-20% by image analysis, using an image analyzer(Image Pro Plus). Furthermore, the physical properties of specimens were improved with increasing milling time as results of hardness, relative density, compressive strength and Young's modulus. Particularly Young's modulus of the sintered alloy using 4h milled powder reached 52 GPa which is similar to bone elastic modulus.