• Biomaterials and Biomechanics in Bioengineering
• /
• v.3 no.2
• /
• pp.71-84
• /
• 2016

The finite element method is wide used in simulation in the biomechanical structures, but a lack of studies concerning finite element mesh quality in biomechanics is a reality. The present study intends to analyze the importance of the mesh quality in the finite element model results from humeral structure. A sensitivity analysis of finite element models (FEM) is presented for the humeral bone and cartilage structures. The geometry of bone and cartilage was acquired from CT scan and geometry reconstructed. The study includes 54 models from same bone geometry, with different mesh densities, constructed with tetrahedral linear elements. A finite element simulation representing the glenohumeral-joint reaction force applied on the humerus during $90^{\circ}$ abduction, with external load as the critical condition. Results from the finite element models suggest a mesh with 1.5 mm, 0.8 mm and 0.6 mm as suitable mesh sizes for cortical bone, trabecular bone and humeral cartilage, respectively. Relatively to the higher minimum principal strains are located at the proximal humerus diaphysis, and its highest value is found at the trabecular bone neck. The present study indicates the minimum mesh size in the finite element analyses in humeral structure. The cortical and trabecular bone, as well as cartilage, may not be correctly represented by meshes of the same size. The strain results presented the critical regions during the $90^{\circ}$ abduction.

• Proceedings of the Korean Society of Veterinary Pathology Conference
• /
• 2003.10a
• /
• pp.57-57
• /
• 2003

Canine osteosarcoma is the most common bone tumor in dog and is characterized by locally aggressive and highly metastatic behavior [1]. Generally malignant tumors meta stasizes by hematogenious routes and rarely through lymphatic pathway, and the lymph node is uncommon metastatic site [2,3]. In this case, the patient has a typical osteosarcoma on his proximal humerus that is the common form of canine OS [4,5]. But the tumor made severe metastatic form to the right axillary lymph node which has a diffuse contribution of osteoid matrix all of the tissue. So, the case is the valuable topic for evaluate the correlation of metastasis to lymph node which is near the primary tumor region and pro gnosis of canine appendicular osteosarcoma. (omitted)

• Biomaterials and Biomechanics in Bioengineering
• /
• v.3 no.2
• /
• pp.115-127
• /
• 2016

Shoulder pain, injury and discomfort are public health and economic issues world-wide. The function of these joints and the stresses developed during their movement is a major concern to the orthopedic surgeon to study precisely the injury mechanisms and thereby analyze the post-operative progress of the injury. Shoulder is one of the most critical joints in the human anatomy with maximum degrees of freedom. It mainly consists of the clavicle, scapula and humerus; the articulations linking them; and the muscles that move them. In order to understand the behavior of individual muscle during abduction arm movement, an attempt has been made to analyze the stresses developed in the shoulder muscles during abduction arm movement during the full range of motion by using the 3D FEM model. 3D scanning (ATOS III scanner) is used for the 3D shoulder joint cad model generation in CATIA V5. Muscles are added and then exported to the ANSYS APDL solver for stress analysis. Sensitivity Analysis is done for stress and strain behavior amongst different shoulder muscles; deltoid, supraspinatus, teres minor, infraspinatus, and subscapularies during adduction arm movement. During the individual deltoid muscle analysis, the von Mises stresses induced in deltoid muscle was maximum (4.2175 MPa) and in group muscle analysis it was (2.4127MPa) compared to other individual four rotor cuff muscles. The study confirmed that deltoid muscle is more sensitive muscle for the abduction arm movement during individual and group muscle analysis. The present work provides in depth information to the researchers and orthopedicians for the better understanding about the shoulder mechanism and the most stressed muscle during the abduction arm movement at different ROM. So during rehabilitation, the orthopedicians should focus on strengthening the deltoid muscles at earliest.

• The Journal of the Korean bone and joint tumor society
• /
• v.10 no.2
• /
• pp.142-146
• /
• 2004

Bizzare parosteal osteochondromatous proliferation is a rare lesion, tends to frequently recur. It was first described in 1983, when Nora and his colleagues reported 35 examples of a proliferative lesion involving small bones of the hand and the feet. It was regarded as occurring only in the small bones of the hand and the feet initially, but from then on, other authors have been reported cases including those involving long bones, skull and maxilla. We experienced a case of bizzare parosteal osteochondromatous proliferation which affects the humeral shaft in a 14-year-old male patient. Radiographs showed calcified mass measuring $4{\times}3$ cm in size and attached to the underlying cortex, which had a broad stalk base. Histologically, it showed hypercellular cartilage maturation to the trabecular bone and plump amount of fibrous stroma in the spaces around the bony trabeculae. Bizzare parosteal osteochondromatous proliferation is a relatively rare lesion, but has a recurrent behavior and histologically tends to be mistaken for malignancy. It can be treated by excision.

• The Korean Journal of Cytopathology
• /
• v.4 no.1
• /
• pp.45-51
• /
• 1993

A 30-year-old woman who was diagnosed as peripheral neuroblastoma by fine needle aspiration of a soft mass of the right upper arm is described. She presented a slowly growing, soft mass of the right upper arm for 1 month. The right humerus revealed no abnormal finding on X-ray. Ultrasonogram of the right upper arm revealed a well demarcated, smooth marginated solid mass without invasion of adjacent structures. Fine needle aspiration was done under the impression of soft tissue tumor with undetermined biologic behavior. The aspirates were highly cellular and the tumor cells were dispersed both singly and in clusters of varying size. The clusters occasionally showed a central capillary core and rosette-like structures. The tumor cells were small in size and had a small to medium amount of cytoplasm. Some of them revealed slender cytoplasmic processes. The nuclei showed distinct nuclear membranes, finely clumped chromatin and small conspicuous nucleoli. Cellular pleomorphism or mitotic figure was not definite. These cytologic findings were interpreted as a malignant, non-lymphomatous small round cell tumor, most likely representing peripheral neuroblastoma or Ewing's sarcoma. Final diagnosis was confirmed by simple excision as peripheral neuroblastoma.