• The Korean Journal of Ceramics
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• 제7권1호
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• pp.41-44
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• 2001

A composite of $Ca_3$(PO$_4$)$_2$ and MgAl$_2$O$_4$ spinel is biologically active and has enduring strength. Its strength depends on the spinel phase. The flaws in the spinel depend on the grain size of the calcium phosphate phase and are not altered by dissolution. The calcium phosphate, ${\alpha}$ tri-calcium phosphate, controls the tissue response. Bone bonds to the implant. A design for a bone graft as a replacement for a section of the diaphysis of a canine femur provides for tensile, compressive, torsional and bending load; and for the physiological processes of bonding and remodeling. A bone plate, used to stabilize the implant at time of surgery was removed after about one year. Over seven years of service have been achieved without internal or external fixation.

• 한국정밀공학회지
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• 제26권6호
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• pp.131-135
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• 2009

In this study, we performed the compressive strength test of trabecular bone in knee joint for measuring the elastic modulus and ultimate strength. The main knee joint is femorotibial articulation between the lateral and medial femorotibial condyle. In the case of osteoarthritis, some patients have only medial condylar osteoarthritis. We performed the mechanical test for comparison the difference of the each condylar strength. We used diamond core-drill and linear precision saw for making the specimens. Specimens were cored from both condyle in distal femur and proximal tibia in fresh cadaver (male 10, female 12), and tested by universal test machine with temperature control saline circulation system. Results of the test in distal femoral parts, averaged elastic modulus was $360.61{\pm}159.40MPa$ for male, $150.89{\pm}70.65MPa$ for female. Averaged ultimate strength was $6.79{\pm}2.91MPa$ for male, $2.89{\pm}1.31MPa$ for female. Male was 2.4 times stronger than female. In the proximal tibial parts, averaged elastic modulus was $108.80{\pm}52.88MPa$ for male, $73.45{\pm}55.06MPa$ for female. Averaged ultimate strength was $2.59{\pm}1.39MPa$ for male, $1.75{\pm}1.16MPa$ for female. Male was 1.5 times stronger than female. In the distal femoral condyle, medial condyle had more strength than lateral condyle at middle region. But lateral condyle had more strength than medial condyle at anterior & posterior regions (p<0.02). In the proximal tibial condyle, medial condyle had more strength than lateral condyle. (p<0.01).

• Experimental and Molecular Medicine
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• 제50권12호
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• pp.3.1-3.14
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• 2018

Type 1 diabetes mellitus (T1DM) is a pathological condition associated with osteopenia. $WNT/{\beta}$-catenin signaling is implicated in this process. Trabecular and cortical bone respond differently to $WNT/{\beta}$-catenin signaling in healthy mice. We investigated whether this signaling has different effects on trabecular and cortical bone in T1DM. We first established a streptozotocin-induced T1DM mouse model and then constitutively activated ${\beta}$-catenin in osteoblasts in the setting of T1DM (T1-CA). The extent of bone loss was greater in trabecular bone than that in cortical bone in T1DM mice, and this difference was consistent with the reduction in the expression of ${\beta}$-catenin signaling in the two bone compartments. Further experiments demonstrated that in T1DM mice, trabecular bone showed lower levels of insulin-like growth factor-1 receptor (IGF-1R) than the levels in cortical bone, leading to lower $WNT/{\beta}$-catenin signaling activity through the inhibition of the IGF-1R/Akt/glycogen synthase kinase $3{\beta}$ ($GSK3{\beta}$) pathway. After ${\beta}$-catenin was activated in T1-CA mice, the bone mass and bone strength increased to substantially greater extents in trabecular bone than those in cortical bone. In addition, the cortical bone of the T1-CA mice displayed an unexpected increase in bone porosity, with increased bone resorption. The downregulated expression of WNT16 might be responsible for these cortical bone changes. In conclusion, we found that although the activation of $WNT/{\beta}$-catenin signaling increased the trabecular bone mass and bone strength in T1DM mice, it also increased the cortical bone porosity, impairing the bone strength. These findings should be considered in the future treatment of T1DM-related osteopenia.

• Imaging Science in Dentistry
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• 제33권2호
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• pp.113-119
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• 2003

Purpose : To evaluate the relationship between morphometric analysis of bone microstructure from digital radiographic image and trabecular bone strength. Materials and Methods : One hundred eleven bone specimens with 5 mm thickness were obtained from the mandibles of 5 pigs. Digital images of specimens were taken using a direct digital intraoral radiographic system. After selection of ROI (100 × 100 pixel) within the trabecular bone, mean gray level and standard deviation were obtained. Fractal dimension and the variants of morphometric analysis (trabecular area, periphery, length of skeletonized trabeculae, number of terminal point, number of branch point) were obtained from ROI. Punch sheer strength analysis was performed using Instron (model 4465, Instron Corp., USA). The loading force (loading speed 1 mm/min) was applied to ROI of bone specimen by a 2 mm diameter punch. Stress-deformation curve was obtained from the punch sheer strength analysis and maximum stress, yield stress, Young's modulus were measured. Results: Maximum stress had a negative linear correlation with mean gray level and fractal dimension significantly (p<0.05). Yield stress had a negative linear correlation with mean gray level, periphery, fractal dimension and the length of skeletonized trabeculae significantly (p < 0.05). Young's modulus had a negative linear correlation with mean gray level and fractal dimension significantly (p < 0.05). Conclusions : The strength of cancellous bone exhibited a significantly linear relationship between mean gray level, fractal dimension and morphometric analysis. The methods described above can be easily used to evaluate bone quality clinically.

• 한국식품영양학회지
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• 제18권1호
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• pp.72-80
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• 2005

본 실험은 칼슘 결핍과 난소 제거로 유발한 골다공증에 대한 한방요법의 효과에 대하여 고찰하였다. 1) 난소 제거로 인한 에스트로겐의 결핍 및 칼슘 결핍은 폐경여성에서 관찰되어지는 것처럼 골강도 및 골밀도의 손실을 일으켰다. 2) 한방 추출물의 투여는 에스트로겐 결핍 및 칼슘 결핍으로 유도된 골강도 및 골밀도 손실에 대한 예방효과가 관찰되었다 3) 난소제거로 인한 에스트로겐의 결핍 및 칼슘 결핍은 골대사의 생화학적 지표들(혈청 중 alkaline phosphatase, acid phosphatase, osteocalcin, 그리고 뇨중 deoxyopyridinoline 농도)에 영향을 미치지 않았다. 4) 한방 추출물의 투여 또한 골 대사의 생화학적 지표들에 영향을 미치지 않았다. 결론적으로, 한방 추출물의 골손실에 대한 예방효과는 한방 추출물의 골다공증 치료제로서의 가능성을 제시하며, 새로운 골다공증 치료제 개발 일환으로 한방추출물의 적용기간 및 농도 변화를 통한 계속적인 연구가 요구되어진다.

• Journal of Nutrition and Health
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• 제41권3호
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• pp.206-215
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• 2008

The purpose of this study was to investigate the effect of manganese (Mn) supplementation on bone status and calcium balance in ovariectomized rats according to the calcium intake levels. Total of 50 Sprague Dawley female rats (6 weeks) were divided into 5 groups and bred for 12 weeks: sham operated control group (SACa), OVX Ca deficiency group (OLCa) with Ca deficiency diet (0.1% Ca modified AIN-93N diet), OVX Ca deficiency & Mn supplement group (OLCaMn), OVX adequate Ca group (OACa; 0.5% Ca AIN-93N diet) and OVX adequate Ca & Mn supplement group (OACaMn). BMD (bone mineral density) of the femur was increased by Mn supplementation in OVX adequate Ca group. However, BMDs of spine, femur and tibia were lowered in OLCa compared to the OLCaMn group. Bone strength of tibia in OLCaMn group was significantly lower than OLCa group. Serum ALP (alkaline phosphatase) and CTx (C-telopeptide of collagen cross-links) levels were significantly higher in ovariectomized rats than those in the sham group, but they were not changed by Mn supplementation. Ca retention rate and Ca absorption rate did not differ among the experimental groups. Urinary Ca excretion was increased by Mn supplementation in Ca deficiency rats. In summary, Mn supplementation resulted in positive effects on bone mineral density ovariectomized rats with which intake adequate Ca. However, Mn supplementation on Ca deficiency ovariectomized rats resulted in decrement of BMO and bone strength by increasing Ca excretion. Therefore, it is encouraged to consider calcium intake levels in supplementation of manganese in order to prevent postmenopausal osteoporosis and to keep bone healthy. (KoreanJNutr2008; 41(3): 206~215)

• 운동영양학회지
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• 제23권4호
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• pp.36-42
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• 2019

[Purpose] The study aimed to determine the effects of bone-specific physical activity on body composition, bone mineral density (BMD), and health-related physical fitness in middle-aged women. [Methods] One hundred eighty-six middle-aged women aged 31-49 years participated in this study. The subjects were divided into tertile groups according to the level of physical activity (low-score group, n=62; middle-score group, n=62; high-score group, n=62). Bone-specific physical activity participation was assessed using the bone-specific physical activity questionnaire. Body composition and BMD were measured using dual-energy X-ray absorptiometry. Health-related physical fitness test included isometric muscle strength (grip strength), muscular endurance (sit-ups), flexibility (sit and reach), and cardiorespiratory fitness (maximal oxygen uptake [VO_2max]). [Results] The high-score group had a significantly higher fat-free mass (p=.045, partial eta-squared value[η_p²]=.033) than the middle- and low-score groups, whereas the high-score group had significantly lower percent body fat (p=.005, η_p²=.056) than the other two groups. Whole-body BMD (p=.034, η_p²=.036) and lumbar BMD (p=.003, η_p²=.060) were significantly higher in the high-score group than in the low-score group. The high-score group performed significantly better for grip strength (p=.0001, η_p²=.101), sit-ups (p=.0001, η_p²=.108), and VO_2max (p=.0001, η_p²=.092) than the other two groups. [Conclusion] The present study suggests that bone-specific physical activity could be useful in improving body composition, BMD, and health-related physical fitness in middle-aged women, significantly enhancing their BMD and health conditions.

• 대한의용생체공학회:의공학회지
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• 제23권6호
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• pp.451-458
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• 2002

골다공증이란 골량의 감소에 의해 야기되며. 해면골 미세구조의 골밀도가 감소하는 질병이다. 약물치료(부갑상선 호르몬)법은 골소주의 두께 및 골의 강도를 어느 정도 증가시킬 수 있는 호르몬 치료법이다. 척추성형술은 골다공성 척추 압박 골절의 치료를 위하여 척추 해면골에 주사기를 통하여 골 시멘트를 주입하는 최소 침습적 수술법이다. 임상적으로 골 시멘트의 물성치에 영향을 미치더라도 점성 감소와 주입 시간 확보를 위해 중합비율을 변경하여 사용한다. 본 연구의 목적은 골 시멘트 중합비율 변경에 따른 척추 해면골의 역학적 특성을 알아보고자 한다. 본 논문에서 는 수정된 보로노이 도형을 이용하여 척추 해면골의 유한요소 모델을 생성하고, 골 시멘트의 중합비율(0.40~l.07$m\ell$/g)에 따른 척추 해면골의 강도회복 정도를 비교하였다. 또한 골다공증 치료에서 호르몬 치료와 골 시멘트 치료의 상대적인 영향을 비교 분석하였다. 분석결과 골 시멘트 치료모델의 탄성계수와 강도는 정상 상태의 약 50%로 회복되었으며, 이 값은 호르몬 치료 모델의 약 2배이다. 0.53$m\ell$/g의 중합비율에서 골 시멘트의 탄성계수와 강도가 최고이며 1.07$m\ell$/g의 중합비율에서 최소의 탄성계수와 강도(각각 42%와 49%)이지만 약물 치료보다는 더 효과적임을 알 수 있다. 척추성형술시 제작사에서 추천하는 중합비율과 다른 비율을 사용할 경우 골 시멘트의 물성치 감소뿐만 아니라 환자의 골 밀도에 따라서 해면골의 강도회복에 문제가 발생할 수 있다는 것을 알 수 있었다.

• 한국콘텐츠학회논문지
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• 제9권5호
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• pp.214-223
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• 2009

운동프로그램이 농촌지역의 여성노인의 악력, 균형 그리고 골밀도에 미치는 영향을 파악하기 위하여 실험군 56명과 대조군 38명을 선정한 후 실험군은 2005년 10월 3일부터 12월 29일까지 주2회, 1회 60분, 13주간 운동프로그램을 실시한 후 운동프로그램에 20회 이상 참석한 33명을 실험군으로, 그리고 대조군 중 2차 측정에 응한 23명이 최종 연구대상이 되어 신체기능 및 골밀도 검사를 실시하여 분석하였으며 그 결과는 다음과 같다. 운동 실시 후 실험군의 악력이 대조군보다 유의하게 향상되었으며(p<0.05), 동적평형성은 실험군이 대조군 보다 유의하게 증가되었고(p<0.01), 골밀도 역시 실험군이 대조군 보다 유의하게 향상되었다(p<0.01) 본 운동프로그램은 여성노인들의 근력, 평형성 및 골밀도 향상에 효과적임을 확인 할 수 있었다.

• 성인간호학회지
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• 제25권1호
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• pp.105-112
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• 2013

Purpose: The purpose of this study was to examine the effects of Tai Chi exercise on muscle strength, balance, flexibility and bone mineral density among community dwelling elderly women. Methods: A quasi-experimental pretest-posttest design with a nonequivalent comparison group was utilized, Elderly women were recruited from the community settings and assigned to either the treatment group (n=30) or the comparison group (n=34). Both groups completed the pretest and the posttest measures at six months with an 29.7% of dropouts. Tai Chi exercise was performed for 60 minutes, three times a week for 24 weeks. The study participants were referred to the sports clinic of the university hospital where an exercise therapist and a technician measured muscle strength, balance, flexibility, and bone mineral density without the knowledge of the group assignment. Data were collected from June 14, 2010 to May 27, 2011. Results: At the completion of 6 month Tai Chi exercise, the experimental group showed a significant difference in knee flexor strength (t=3.26 p=.002), flexibility (t=-2.93, p=.005), and bone mineral density in femur (t=2.20, p=.032), compared to the control group. Conclusion: Tai Chi exercise could be performed safely to community dwelling elderly women and effective for preventing declining in physical function in this population. Whether or not this health benefits would lead fall prevention will require further study.