• Title/Summary/Keyword: bone strength

Search Result 499, Processing Time 0.032 seconds

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

  • Shin, Sang-Jin
    • Clinics in Shoulder and Elbow
    • /
    • v.11 no.2
    • /
    • pp.82-89
    • /
    • 2008
  • Ideal rotator cuff repair is to maintain high fixation strength and minimize gap formation for optimizing the environment of biologic healing of tendon to bone. Among the current repair techniques, the suture bridge technique is superior to single- or double-row repair in ultimate load to failure, gap formation, restoring anatomical footprint and achieving pressurized contact area. The suture bridge technique also minimizes gap formation and has rotational and torsional resistances allowing early rehabilitation. However, despite superior biomechanical characteristics of the suture bridge technique, there is no evidence that these mechanical advantages result in better clinical outcomes. Furthermore, there is no difference in failure rates between the double-row repair and suture bridge techniques. An appropriate repair technique should be determined based on tear size and pattern and tendon quality.

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

  • Park, Jun-Woo;Choi, Jin-Young;Kim, Hyung-Wook;Kim, Jong-Sik;Choung, In-Won;Kang, Jin-Han;Hong, Soon-Min
    • Maxillofacial Plastic and Reconstructive Surgery
    • /
    • v.29 no.4
    • /
    • pp.340-352
    • /
    • 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.

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

  • 박미나
    • Journal of Nutrition and Health
    • /
    • v.30 no.1
    • /
    • pp.3-11
    • /
    • 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.

  • PDF

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
    • /
    • v.39 no.2
    • /
    • pp.113-117
    • /
    • 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.

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

  • Kim, Ae-Kyung;Yoo, Eun-Kwang
    • Women's Health Nursing
    • /
    • v.3 no.1
    • /
    • pp.82-92
    • /
    • 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.

  • PDF

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

  • Chung, Hyun Kee;Choi, Choong Hyeok;Kim, Jong Heon;Kim, Jae Young
    • Journal of the Korean Arthroscopy Society
    • /
    • v.3 no.1
    • /
    • pp.30-34
    • /
    • 1999
  • We report the case of a 30-year-old man who was presented with transient calcification on the graft shortly after anterior cruciate ligament(ACL) reconstruction using a autogenous bone patellar tendon. The patient underwent ACL reconstruction with two incisional technique and six month later, calcific density was seen radiologically around the graft. On postoperative 13 months follow-up radiographic films, the calcific density disappeared. After two months of operation, Lachman and pivot shift test were negative and one millimeter side to side difference was detected in KT-1000 with 20 Ibs strength. But 6 months after the reconstruction, mild anterior instability was detected with the calcific density around the grafted tendon. However the anterior stability was recovered according to the disappearance of calcific density.

  • PDF

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

  • Oh, Seung-Han
    • The Journal of the Korean dental association
    • /
    • v.48 no.2
    • /
    • pp.106-112
    • /
    • 2010
  • Tissue engineering has been enhanced by advance in biomaterial nature, surface structure and design. In this paper, I report specifically vertically aligned titania ($TiO_2$) nanotube surface structuring for optimization of titanium implants utilizing nanotechnology. The formation, mechanism, characteristics of titania nanotubes are explained and emerging critical role in tissue engineering and regenerative medicine is reviewed. The main focus of this paper is on the unique 3 dimensional tubular shaped nanostructure of titania and its effects on creating epochal impacts on cell behavior. Particularly, I discuss how different cells cultured on titania nanotube are adhered, proliferated, differentiated and showed phenotypic functionality compared to those cultured on flat titanium. As a matter of fact, the presence of titania nanotube surface structuring on titanium for dental applications had an important effect improving the proliferation and mineralization of osteoblasts in vitro, and enhancing the bone bonding strength with rabbit tibia over conventional titanium implants in vivo. The nano-features of titania nanotubular structure are expected to be advantageous in regulating many positive cell and tissue responses for various tissue engineering and regenerative medicine applications.

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

  • In Yong;Bahk Won-Jong;Park Jong-Beom;Hong Seung-Hwan
    • Journal of the Korean Arthroscopy Society
    • /
    • v.6 no.1
    • /
    • pp.60-63
    • /
    • 2002
  • Purpose : The purpose of this study was to introduce new femoral fixation technique using a cross-pin and a bioabsorbable interference screw in hamstring ACL reconstruction. Method : Semitendinosus and gracilis were harvested for quadrapled graft. After tibial tunnel had been made, femoral tunnel was made 35 mm in depth. Then the graft passed through the tunnels. Cross-pin was fixed through the drill hole which had been made through upper sleeve of the Rigidfix system. While pulling the graft, bioabsorbable interference screw was fixed through the anteromedial portal. Conclusion : We introduced the new femoral fixation technique using a cross-pin and a bioabsorbable interference screw as a good method with high fixation strength and tight graft-bone contact.

  • PDF

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

  • Rots, Jan G.;Invernizzi, Stefano;Belletti, Beatrice
    • Computers and Concrete
    • /
    • v.3 no.4
    • /
    • pp.213-233
    • /
    • 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
    • Korean Journal of Materials Research
    • /
    • v.24 no.2
    • /
    • pp.111-115
    • /
    • 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.