• Clinics in Shoulder and Elbow
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• 제25권1호
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• pp.5-14
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• 2022

Background: The purpose of this study was to verify the effect of protocatechuic acid (PCA) on tendon healing and fatty degeneration in a chronic rotator cuff model. Methods: Twenty-eight Sprague-Dawley male rats were randomly allocated into two groups: Saline+repair (SR) and PCA+repair (PR). The right shoulder was used for experimental interventions, and the left served as a control. PCA (30 mg/kg/day) was administered intraperitoneally at the site of infraspinatus tendon detachment in rats in the PR group, and the same volume of saline was administered to the same site in the SR group. The torn tendon was repaired 4 weeks after infraspinatus detachment. Four weeks after repair, hematoxylin and eosin (H&E), S100, and CD68 stains were performed to evaluate the degree of fatty degeneration and H&E and Masson trichrome stains were performed to assess tendon healing. Superoxide dismutase (SOD) was measured to test the efficacy of PCA as an antioxidant. Results: Results from histological evaluation indicated that SOD and CD68 levels at the musculotendinous region and collagen fiber parallel to the orientation at the tendon-to-bone junction were not significantly different between the SR and PR groups. The mean load-to-failure of the PR group (20.32±9.37 N) was higher than that of the SR group (16.44±6.90 N), although this difference was not statistically significant (p=0.395). The SOD activity in the operative side infraspinatus muscle of the PR group was higher than that of the SR group, but the difference was not statistically significant (p=0.053). Conclusions: The use of PCA could improve tendon healing and decrease fatty degeneration after rotator cuff repair.

• Clinics in Shoulder and Elbow
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• 제26권2호
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• pp.131-139
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• 2023

Background: Massive rotator cuff tears (RCTs) are complicated by muscle atrophy, fibrosis, and intramuscular fatty degeneration, which are associated with postoperative tendon-to-bone healing failure and poor clinical outcomes. We evaluated muscle and enthesis changes in large tears with or without suprascapular nerve (SN) injury in a rat model. Methods: Sixty-two adult Sprague-Dawley rats were divided into SN injury (+) and SN injury (-) groups (n=31 each), comprising tendon (supraspinatus [SSP]/infraspinatus [ISP]) and nerve resection and tendon resection only cases, respectively. Muscle weight measurement, histological evaluation, and biomechanical testing were performed 4, 8, and 12 weeks postoperatively. Ultrastructural analysis with block face imaging was performed 8 weeks postoperatively. Results: SSP/ISP muscles in the SN injury (+) group appeared atrophic, with increased fatty tissue and decreased muscle weight, compared to those in the control and SN injury (-) groups. Immunoreactivity was only positive in the SN injury (+) group. Myofibril arrangement irregularity and mitochondrial swelling severity, along with number of fatty cells, were higher in the SN injury (+) group than in the SN injury (-) group. The bone-tendon junction enthesis was firm in the SN injury (-) group; this was atrophic and thinner in the SN injury (+) group, with decreased cell density and immature fibrocartilage. Mechanically, the tendon-bone insertion was significantly weaker in the SN injury (+) group than in the control and SN injury (+) groups. Conclusions: In clinical settings, SN injury may cause severe fatty changes and inhibition of postoperative tendon healing in large RCTs. Level of evidence: Level Basic research, controlled laboratory study.

• Smart Structures and Systems
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• 제22권1호
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• pp.57-70
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• 2018

For the long-term structural health monitoring of civil structures, the effect of ambient temperature variation has been regarded as one of the critical issues. In this study, a principal component analysis (PCA)-based algorithm is proposed to filter out temperature effects on electromechanical impedance (EMI) monitoring of prestressed tendon anchorages. Firstly, the EMI monitoring via a piezoelectric interface device is described for prestress-loss detection in the tendon anchorage system. Secondly, the PCA-based temperature filtering algorithm tailored to the EMI monitoring of the prestressed tendon anchorage is outlined. The proposed algorithm utilizes the damage-sensitive features obtained from sub-ranges of the EMI data to establish the PCA-based filter model. Finally, the feasibility of the PCA-based algorithm is experimentally evaluated by distinguishing temperature changes from prestress-loss events in a prestressed concrete girder. The accuracy of the prestress-loss detection results is discussed with respect to the EMI features before and after the temperature filtering.

• Journal of Ginseng Research
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• 제46권4호
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• pp.526-535
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• 2022

Background: During the pathogenesis of tendinopathy, the chronic inflammation caused by the injury and apoptosis leads to the generation of scars. Ginsenoside Rg1 (Rg1) is extracted from ginseng and has anti-inflammatory effects. Rg1 is a unique phytoestrogen that can activate the estrogen response element. This research aimed to explore whether Rg1 can function in the process of tendon repair through the estrogen receptor. Methods: In this research, the effects of Rg1 were evaluated in tenocytes and in a rat model of Achilles tendinitis (AT). Protein levels were shown by western blotting. qRT-PCR was employed for evaluating mRNA levels. Cell proliferation was evaluated through EdU assay and cell migration was evaluated by transwell assay and scratch test assay. Results: Rg1 up-regulated the expression of matrix-related factors and function of tendon in AT rat model. Rg1 reduced early inflammatory response and apoptosis in the tendon tissue of AT rat model. Rg1 promoted tenocyte migration and proliferation. The effects of Rg1 on tenocytes were inhibited by ICI182780. Rg1 activates the insulin-like growth factor-I receptor (IGF1R) and MAPK signaling pathway. Conclusion: Rg1 promotes injured tendon healing in AT rat model through IGF1R and MAPK signaling pathway activation.

• 콘크리트학회논문집
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• 제20권6호
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• pp.697-704
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• 2008

이 논문은 외부 강선으로 보강된 PSC 교량의 시공단계가 고려된 비선형거동 예측을 위한 연구이다. 해석시 비부착 텐던 요소와 유연도법에 근거한 보-기둥 요소를 사용하였다. 비부착 텐던 모델은 PSC 구조물의 콘크리트내의 텐던의 거동을 모사하며 포스트텐션 (posttensioned) 구조물의 프리스트레싱력과 전달을 효율적으로 모사할 수 있다. 이 모델은 여러 절점과 세그먼트로 구성되며 PSC 구조물내의 같은 위치의 텐던을 하나의 텐던 요소로 모사할 수 있다. 보-기둥 요소는 분산균열 개념에 기초한 철근콘크리트 비선형 재료모델을 포함하고 있다. 유연도법에 근거하여 유도된 보-기둥 요소의 각각의 파이버는 콘크리트와 철근의 일축 거동을 모사한다. 보-기둥요소와 비부착 텐던 요소는 RC 및 PSC 구조물의 상세 비선형해석을 수행할 수 있는 RCAHEST (reinforce concrete analysis in higher evaluation system technology)에 이식하였다. 외부 강선으로 보강된 PSC 구조물에 대한 수치기법은 신뢰성 있는 실험 결과와 비교하여 검증하였다.

• Journal of the Optical Society of Korea
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• 제19권2호
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• pp.175-181
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• 2015

Optical coherence tomography (OCT) is a noninvasive technique for microscopic investigation of tissue. We thought that the OCT method could be a potential tool for monitoring the healing process of a tendon. In this study we used two rat models, denervated and non-denervated groups, to observe a variety of healing phases of Achilles tendon (AT) injury. We made samples of AT injury lesions, to take OCT images and to make histopathological samples of serial sectional tissue. In an OCT image the denervated rat showed no specific finding, but the non-denervated rat showed a large defect lesion that was scaffolding tissue. OCT findings combined with pathologic findings showed advantages in visualization of tendon microstructure over other imaging modalities such as MRI and US, and OCT is beneficial to making a treatment plan, especially the timing and intensity of rehabilitation. Therefore a multimodal platform using OCT for evaluation of tendon injury may be potentially useful for many applications.

• 한국정보처리학회논문지
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• 제6권12호
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• pp.3435-3446
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• 1999

CAD툴을 손 재활수술에 응용하는 것은 새로운 시도이다. 현재까지 힘줄이식수술과 같은 복잡한손 재활 수술에 있어서 외과의사를 보조할 수 있는 시스템은 거의 없는 것으로 사료된다. 대부분의 힘줄 이식수술은 의사의 다년간 시술로 축적된 의학적 지식과 경험에 의해 행해지는 것이 보통이다. 그러나 힘줄이식수술에 이러한 힘줄경로설계를 위한 CAD 툴을 활용한다면 최선의 시술계획과 평가가 가능하게 될 것이다. 이 연구의 목적은 힘줄이식수술이 좀더 객관적이고 정량적으로 행해질 수 있도록 환자의 손을 기구학적으로 모델링한 후 표준 그래픽스 라이브러리를 사용하여 프로토타입 힘줄경로설계용 CAD툴을 디자인하는데 있다.

• Advances in nano research
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• 제14권6호
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• pp.591-602
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• 2023

In the present study, capability of nanobiotics in repairing tendon injuries commonly occur in Taekwondo sport is investigated and some approaches are proposed. In this regard, a brief review on the types and application of nanobiotics is presented. Their capabilities and limitation are discussed. Next, different type of tendon injuries in Taekwondo athletes are discussed along with their treatment approaches. Based on the presented data, a nano-scale feasible robot model carrying nanobiotics is proposed for repairing tendons. Finite element simulations is also conducted to show the effectiveness of the repairing process using nanorobots equipped with nanobiotics. This repairing procedure is a combination of mechanical and chemical treatments. The results indicated that using nanobiotics on nanorobots arms in the repair of tendon injuries has many benefits. First, drug delivery is directly injected to the target section. Second, Due to the nanorobots small sizes more acute treatment is possible. Finally, since the control of the nanorobots are assisted with computers, the possibility of human error reduces significantly. The proposed method of the present study could be utilized by other scientists and technological industry in developing final nanorobots with nanobiotics carrying capacity.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 추계학술대회 논문집
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• pp.979-980
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• 2010

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1992년도 추계학술대회논문집
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• pp.46-53
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• 1992

Finger movements in the sagittal plane mainly consist of flexion and extension about the metacarpophalangeal(MCP) and proximal interphalangeal(PIP) joints. A kinematic finger model was developed with the assumption of constant tendon moment arms. Equations of static equilibrium were derived for the finger model using the principle of virtual work. Equations of static equilibrium for the finger model were indeterminate since only three equations were available for five unknown variables(forces). The number of variables was reduced based on information on muscular activities in finger movements. Then the amounts of forces which muscles exerted to maintain static equilibrium against external loads were computed from the equilibrium equations. The muscular forces were expressed mathematically as functions of finger positions, tendon moment arms, lengths of phalanges, and the magnitude and direction of external load. The external finger strength were computed using the equations of muscular forces and anatomical data. Experiments were performed to measure finger strengths. Measurements were taken in combinations of four finger positions and four directions of force exertions. Validation of the finger models and of procedure to estimate finger strengths was done by comparing the results of computations and experiments. Significang differences were found between the predicted and measured finger strengths. However, the trends of finger strengths with respect to finger positions were similar inboth the predicted and measured. These findings indicate that the finger model and the procedure to predict finger strengths were correctly developed.