• Journal of Biomedical Engineering Research
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• v.22 no.5
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• pp.419-424
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• 2001

We intended to evaluate the Young's modulus of trabecular bone of a human distal femur by spherical Indentation test and CT images and to quantify relationships between the direction of load, density. and Young's modulus. The specimens were scanned at 1 mm intervals on CT scanner After scanning the bones were sectioned with diamond saw. producing 8mm cubes of trabecular bone. The tubes were mechanically tested in inferior-superior(IS), anterior-posterior(AP). and medial-lateral(ML) direction with custom-made device. After testing, the real apparent density of specimens were measured. The results of this study showed that the IS modulus was significant1y greater than both the AP and ML modulus and the AP modulus was also greater than ML modulus significantly(p〈0.01) A significant Power relationship between the apparent density and the modulus was also found.

• The Journal of the Korean bone and joint tumor society
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• v.1 no.2
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• pp.164-170
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• 1995

Eight patients with Ewing's sarcoma were treated between September 1983 and September 1992 at medical college, Department of Orthopaedic Surgery, Guro Hospital, Korea University. There were 5 males and 3 femails, with mean age of 28.2 years(ranging from 2-66 years). Three patients with soft tissue Ewing's tumor were excluded from the study. Of the eight patients, two patients presented with multiple metastasis, two cases occurred in the rib, and in the distal femur, mandible, scapular, 3rd, 4th thoracic spine in each patients. Chemotherapy alone was applied in 3 patients, radiotherapy alone in 1 patient, 2 patients were treated with chemotherapy and radiotherapy. Four patients died from the disease itself. Remissions were achieved in the other 4 patients. However, among them two patients relapsed 5 and 36 months later, I patient was not able to be followed, I patient died due to sepsis. The poor prognosis observed for patients with axial lesions should encourage other methods of managing these tumors.

• Journal of Korean Orthopaedic Sports Medicine
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• v.8 no.1
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• pp.60-63
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• 2009

Trevor's disease, also known as dysplasia epiphysealis hemimelica, is rare abnormality characterized by aberrant cartilaginous overgrowth forming one half of epiphysis. Typically the patient is 2 to 14 years of age. Until now only six cases, including a case recurred after surgery, have been reported in Korea. A seven year-old boy complained pain of the left knee. However, any deformity of the knee was not seen. The plain radiographic findings showed multiple ossifications asymmetrically on the medial epiphysis of distal femur. The magnetic resonance imaging (MRI) clearly demonstrated the epiphyseal mass which contained low signal spots corresponding to calcified foci and abnormal cartilaginous overgrowth. We report one additional case with a brief review of literature with the MRI findings.

• Proceedings of the KOSOMBE Conference
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• v.1994 no.12
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• pp.71-74
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• 1994

In cementless total hip arthroplasty(THA), an initial stability of the femoral component is mandatory to achieve bony ingrowth and secondary long term fixation. Bone ingrowth depends strongly on relative micromotion and stress distributions at the interface. Primary stability of the femoral component can be obtained by minimizing the magnitude of relative micromotions at bone-prosthesis interface, Hence an accurate evaluation of interface behavior and stress/strain fields in the bone implant system may be relevant for better understanding of clinical situations and improving THA design. However, complete evaluation of load transfer in the bone remains difficult to assess experimentally, Hence, recently finite element method (FEM) was introduced in orthopaedic research field to fill the gap due to its unique capacity to evaluate stress in structure of complex shape, loading and material behavior. The authors developed the 3-dimensional numerical finite element model which is composed of totally 1179 elements off and 8 node blick. We also analyzed the micromotions at the bone-stem interface and mechanical behavior of existing bone prosthesis for a loading condition simulating the single leg stance. The result indicates that the values of relative motion for this well fit Multilock stem were $150{\mu}m$ in maximum, $82{\mu}m$ in minimum, and the largest relative motion developed in medial region of proximal femur with anterior-posterior direction. The proximal region of the bone was much larger in motion than the distal region and the stress pattern shows high stress concentration on the cortex near the tip of the stem. These findings indicates that the loading in the proximal femoral bone in the early postoperative situation can produce micromotions on the interface and clinically cementless TEA patient should not be allowed weight bearing strictly early in the postoperative period.

• The Korean Journal of Applied Statistics
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• v.31 no.3
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• pp.353-366
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• 2018

This study uses mixed-effects models to predict thigh soft tissue artefact (STA), relative movement of soft tissue such as skin to femur occurring during hip joint motions. The random effects in the model were defined as STA and the fixed effects in the model were considered as skeletal motion. Five male subjects without musculoskeletal disease were selected to perform various hip joint rotational motions. Linear mixed-effects models were applied to markers' position vectors acquired from non-invasive method, photogrammetry. Predicted random effects showed similar patterns of STA among subjects. Large magnitudes of STA appeared on the points near the hip joint regardless of sides; however, small values appeared on the distal anterior.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.13 no.2
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• pp.203-216
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• 1991

Nerve allografts as a bridge of regeneration is useful in the repair of peripheral nerve defect resulting from trauma, and leprosy. But immunological rejection and complicated scar formation is an unavoidable problem in the application of allogeneic nerves. This article is intended to study of the regeneration of allogeneic nerve grafts in rats with histopathologically, scanning electron microscopically. 24 adult male Sprague-Dawley rats were used as the experimental animals. A 2cm skin incision was made on the lateral aspects of limb, parallel to femur. Segments of sciatic nerve trunk taken from rats, 10mm was resected at the middle of the thigh, nerve graft was inserted between the ends of gaps with perineural and epineural suture method with 10-0 prolene. Obsrevation was made simultaneously at 3 day, 1, 2, 3, 4, 5, 6, 8 weeks after surgery. The results were as follows. 1. In light and electronic microscopic studies, marked degenerative change of the graft nerves were observed at 2 weeks after surgery. 2. After surgery, blood clot fromation was observed at 3 day, granualtion tissue formation was observed at 2 week, and fibrous tissue proliferation was observed at 3 week. 3. In change of nerve fiber, there were Wallerian degeneration at early stage, decrease in degeneration at 4 week but degeneration of myeline was continuded at 8 week. 4. At 4 week, schwann cells proliferate at its cut ends to join with the distal and proximal stump of the damaged nerve. 5. Fibrous scar tissues are formed at 2 weeks and increased progressively in 8 weeks, which was interrupted the regeneration of grafted nerve.

• The Journal of the Korean bone and joint tumor society
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• v.16 no.1
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• pp.42-46
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• 2010

Angiomyxolipoma is a rare variant of lipoma, which is described by Mai, 1996, at first. The nine cases of which have been reported to date. Microscopically, the lesion consists of adipose tissue with the paucicellular myxoid areas and fat tissue with numerous thin, dilated, and congestive blood vessels. The reported cases mostly located to the superficial layer on the scalp, subungual, extremities in adults. We report one case of angiomyxolipoma located in the submuscular and parosteal area in the distal femur around knee joint in a child.

• Journal of Genetic Medicine
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• v.12 no.2
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• pp.123-127
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• 2015

Distal limb deformities are congenital malformations with phenotypic variability and high genetic heterogeneity. Split hand/foot malformation, also known as ectrodactyly, is a congenital limb malformation characterized by a defect of the central rays of the hands and/or feet. Split hand/foot malformation with long-bone deficiency (SHFLD) is a rare condition related to a 17p13.3 duplication. Recently, genomic duplications encompassing BHLHA9 have been associated with SHFLD. We report a case of SHFLD presenting with campomelia of the right femur, bilateral agenesis of fibulae, bilateral club feet, and oligosyndactyly of the hands and feet, that was associated with a 17p13.3 duplication, as determined prenatally using array comparative genomic hybridization.

• The Journal of the Korean bone and joint tumor society
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• v.3 no.1
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• pp.1-8
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• 1997

Osteosarcoma is the most common primary bony malignancy and its survivorship has been progressed markedly through refined chemotherapy and surgery. But still there are many non-responders and analysis of prognostic factors may be helpful for them. Two hundred and sixty-six patients were enlisted between Mar, 1985 and Sep. 1994. Among them our inclusion criteria were: 1)primary, nonmetastatic classical osteosarcoma 2)extremity in location 3)no prior treatment at other institute and completed neoadjuvant chemotherapy and surgery according to our protocol. One hundred and eleven cases were eligible. Analyzed factors were:age, sex, location, tumor size, and pathologic response. Statistical methods were log-rank test for univariate and Cox's test for multivariate analysis. Male to female ratio was 69:42 with an average age of 17.2 years. Locations of tumor were distal femur 59, proximal tibia 29, and proximal humerus 8. Tumor size were measured by its maximal diameter and 48 cases were above 10cm and 47 cases were below 10cm. For pathologic response, 57 cases showed more than 90% and 54 cases were less than that. Limb salvage procedure was 101 cases and amputation was 10 cases and their local recurrence rate were 3.6%. Average follow-up period was 24(9-78.2) months and their final status was CDF 86, AWD 8, NED 5, and DOD 12 cases. In univariate study: type of operation(p=0.005), tumor size(p=0.005), and pathologic response(p=0.02) were significant variables. Pathologic response(p=0.03) and type of operation(p=0.01) were meaningful prognostic factors on multivariate analysis. But the latter result was interpreted as a bias, so pathologic response remained as a sole meaningful prognostic factor. More aggressive chemotherapy will be needed to improve the survival.

• The Journal of the Korean bone and joint tumor society
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• v.18 no.1
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• pp.45-49
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• 2012

Skip lesion is not uncommon feature in osteosarcoma and considered to be importantly associated with poor prognosis factor, and thus, should be excised with the main mass. The accurate pre-operative evaluation of the intramedullary extent of osteosarcoma is essential, because it determines the level of bone resection. Among the reliable detection methods, bone scan has a drawback of high rate of false negative results and regional MRI has a difficulty to cover the whole involved lesions without clinical suspicion. The authors report a case of osteosarcoma of the distal femur with a proximal skip lesion that was not detected by either regional MR imaging or by bone scan, but which was visualized by FDG-PET/CT.