• Clinics in Shoulder and Elbow
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• v.16 no.2
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• pp.170-177
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• 2013

Total elbow arthroplasty is still in its infancy compared with other arthroplasties, such as knee or hip arthroplasties. Implant design has been evolving with clinical experiences; however, there are only limited data on the long-term clinical outcome of elbow arthroplasty in the literature. The design of total elbow prostheses can be divided into three categories: linked (constrained or semi-constrained), unlinked (unconstrained), and convertible types. The choice between an unlinked (unconstrained) implant and a linked (semi-constrained) implant depends on joint stability and adequacy of the bone stock. Linked elbow arthroplasty has provided high patient satisfaction, and pain relief thanks to proper patient selection, advancement of implant design, improvement in cement techniques, meticulous surgical technique, and appropriate postoperative rehabilitation. Concerns remain about the use of this implant in young or high-demand patients. This article focuses on the linked (semi-constrained) prostheses, which provides an overview of the current state of linked total elbow arthroplasty.

• Journal of the Korean Society of Safety
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• v.12 no.3
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• pp.178-184
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• 1997

Many mathematical techniques have been developed to determine the muscle forces and force distribution in biomechanical human model, because it is so important to understand internal forces resisting external loading. However, a three-dimensional mathematical model of wrist joint, which is essential to develop solid modeling and artificial wrist joint, has not been well developed. This study proposed to define three-dimensional mathematical model of distal radius and ulna of the human wrist and to develop a detailed two-dimensional finite element through comparisons to existing analytical models and experimental tests. This mathematical model were accurately recreated, allowing the internal tendon force as well as force transmission and distribution through the distal radios and ulna during dynamic loadings. The results found in this study indicate and support the findings of other investigator that cyclic loading condition results in higher compression force on distal radius and ulna and may be source of wrist disorder.

• Transactions of the KSME C: Technology and Education
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• v.1 no.2
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• pp.153-165
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• 2013

The established gait analysis studies have regarded leg as one single spring. If we can design a knee-ankle actuating mechanism as a primary actuator for supporting knee extension, it might be possible to revolutionary store or release elastic strain energy, which is consumed during the gait cycle, and as a result leg stiffness is expected to increase. An ankle joint actuating mechanism that stores and releases the energy in ankle joint is expected to support and solve excessive artificial leg stiffness caused by the knee actuator (primary actuator) to a reasonable extent. If unnecessary kinematic energy is released with the artificial speed reduction control designed to prevent increase in gait speed caused by increase in time passed, it naturally brings question to the effectiveness of the actuator. As opposed to the already established studies, the authors are currently developing knee-ankle two actuator system under the concept of increasing lower limb stiffness by controlling the speed of gait in relative angular velocity of the two segments. Therefore, the author is convinced that compensatory mechanism caused by knee actuating must exist only in ankle joint. Ankle joint compensatory mechanism can be solved by reverse-examining the change in metatarso-phalangeal joint (MTPJ) tilt angle (${\theta}_1=0^{\circ}$, ${\theta}_2=17^{\circ}$, ${\theta}_3=30^{\circ}$) and the effect of change in gait speed on knee activity.

• Journal of the Korean Orthopaedic Association
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• v.56 no.3
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• pp.277-281
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• 2021

Iliac vein compression syndrome, which results in thrombosis of the left iliac veins, was first described by May and Thurner in 1957. May-Thurner syndrome should be considered when deep vein thrombosis-like symptoms appear, especially in the left lower extremities without an invasive procedure. The authors encountered an interesting case of a middle-aged female patient, who presented with sudden pain, swelling and skin color changes to the left lower extremity after right total knee arthroplasty and was diagnosed May-Thurner syndrome by computed tomography venography. This case is of clinical significance in that the early diagnosis of May-Thurner syndrome in the left lower extremity was made, which might have been overlooked after right total knee arthroplasty. This case is reported with a review of the literature review.

• Journal of Korean Foot and Ankle Society
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• v.25 no.4
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• pp.181-184
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• 2021

End-stage ankle arthritis is a debilitating condition that causes functional limitations and consequently a poor quality of life. Total ankle replacement arthroplasty is a good alternative to arthrodesis for preserving the ankle's range of motion. However, many complications can occur in patients with rheumatoid arthritis and with poor soft tissue and bone conditions. A 61-year-old female experienced spacer subluxation after surgery, which was not reduced by medial soft tissue release and spacer change. Buttress plating was found to be a good treatment option to prevent spacer subluxation and can be considered in patients with rheumatoid arthritis with bone erosion and soft tissue damage.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.7
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• pp.31-37
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• 2009

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1570-1574
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• 2008

Various mechanical test were conducted on conventional and crosslinked ultra-high molecular weight polyethylene(UHMWPE) all prepared from the same lot of medical grade GUR 1050 for artificial joint. The conventional materials were not irradiated and treated by heating. The cosslinked materials were irradiated with $25kGy{\sim}200kGy$ by gamma-ray andthen annealed or remelted. Gamma-ray irradiation and heat treatment process were found to significantly impact the crystallinity, and hence the mechanical behavior, of the highly crosslinked UHMWPE. The radiation dose and heating conditions were key predictors of the uniaxial yielding, plastic flow, and failure properties of conventional and highly crosslinked UHMWPE. The correlation model from experiments would be the basic information to enhance the were resistance of artificial joint liner.

• Annual Conference of KIPS
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• 2022.11a
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• pp.600-602
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• 2022

2차원 이미지 또는 영상을 통한 자세 추정의 경우, 영상 내에서 발생할 수 있는 탐지 오류, 피사체 잘림, 폐색(Occlusion) 등으로 인해 자세 추정 정확도가 감소할 수 있다. 본 논문에서는 4장 이상의 다양한 각도로 촬영한 이미지를 NeRF(Neural Radiance Fields)를 통해 이미지 합성(Image synthesis)을 진행하여 3차원 모델을 생성한다. 이후 DeepLabCut을 사용하여 관절 좌표와 골격(Skeleton)을 구축한다. 구축한 골격을 인공지능에 학습시킨 뒤 2차원 영상에서의 관절 좌표 인식, 골격 구축, 자세 추정을 진행한다. 2차원 영상 테스트 데이터를 통해, 3차원 모델을 사전 학습한 인공지능 모델과 기존 2차원 이미지를 사용하여 학습한 인공지능 모델의 자세 추정 정확도를 비교한다.

• The Academic Congress of Korean Shoulder and Elbow Society
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• 2003.11a
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• pp.175-180
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• 2003

상완골 근위부 골절의 치료를 위해서 실시하는 상완골 두 치환술은 고난도의 수술이다. 그러나 수술 수기에 만전을 기하고 골절을 위해서 특별하게 고안된 치환물을 사용하면 통증을 해소되는 것은 물론이며 대부분의 견관절 기능도 회복이 가능하다고 생각한다. 또한 보다 좋은 결과를 얻기 위해서는 치환물과 수술 수기 등에 대해서 지속적인 개선이 매우 중요하다고 생각한다.

• The Academic Congress of Korean Shoulder and Elbow Society
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• 1999.03a
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• pp.41-47
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• 1999