• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.245-248
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• 1997

Operative interventions for the management of osteonecrosis of the femoral head (ONFH) include core drilling, with or without vascularized fibular bone grafting. Nevertheless, their clinical results have not been consistently satisfactory. Recently, a new surgical procedure that incorporates cementation with polymethylmethacrylate (PMMA) after core drilling has been tried clinically. In this study, a biomechanical analysis using a finite element method(FEM) was undertaken to evaluate surgical methods and their underlying surgical parameter. Our finite element models included five types. They were (1) normal model (Type I), (2) necrotic model (Type II), (3) core decompressed model (Type III). (4) fibular bone grafted model (Type IV), and (5) cemented with PMMA model (Type V). The geometric dimensions of the femur were based on digitized CT-scan data of a normal person. Various physiological loading conditions and surgical penetration depths by the core were used as mechanical variables to study their biomechanical contributions in stress transfer within the femoral head region. In addition. the peak von Mises stress(PVMS) within the necrotic cancellous bone of the femoral head was obtained. The fibular bone grafted method and cementation method provided optimal stress transfer behaviors. Here. substantial increase in the low stress level was observed when the penetration depth was extended to 0mm and 5mm from the subchondral region. Moreover, significant decrease in PVMS due to surgery was observed in the fibular bone grafted method and the cementation method when the penetration depths were extended up to 0 and 5mm from the subchondral region. The drop in PVMS was greater during toe-off than during heel-strike (57% vs. 28% in Type IV and 49% vs. 22% in Type V). Both the vascularized fibular bone grafting method (Type IV) and the new PMMA technique (Type V) appear to be very effective in providing good stress transfer and reducing the peak Von-Mises stress within the necrotic region. Overall results show that fibular bone grafting and cementation methods are quite similar. In light of above results, the new cementation method appears to be a promising surgical alternative or the treatment of ONFH. The use of PMMA for the core can be less prone to surgical complication as opposed to preparation of fibular bone graft and can achieve more immediate fixation between the core and the surrounding region.

• Journal of Microbiology and Biotechnology
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• v.24 no.3
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• pp.394-400
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• 2014

Avascular necrosis of the femoral head (ANFH) is commonly observed in patients treated with excessive glucocorticoid (GC). Single administration of lipopolysaccharide (LPS) has shown to induce immune stimulatory factors. However, the effect of repeated administration of LPS on GC-induced ANFH has not been studied. Thus, the purpose of this study was (i) to examine the cytokine profile induced by repeated LPS administrations and (ii) to test the effect of repeated LPS treatments on GC-induced ANFH. A mouse necrosis model of ANFH was designed by chronic GC administration with co-treatment of LPS. Mice body weights in the LPS/prednisolone (PDN) co-treated group were lower than that of the untreated control group, but spleen weights were greater than the control group. The levels of IL-6, $TNF{\alpha}$, and IL-33 in the liver and spleen of the LPS/PDN group were lower than the untreated control group, whereas $TNF{\alpha}$ level in the femoral head of the LPS/PDN group increased. Collectively, the effect of repeated LPS on the pathogenesis of GC-induced ANFH was associated with the $TNF{\alpha}$ level in the femoral head, but the pathogenesis did not correspond to cytokine levels in immune tissues.

• Journal of Biomedical Engineering Research
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• v.19 no.4
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• pp.341-350
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• 1998

The accurate measurement of the femoral anteversion is important for the derotational osteotomy. To estimate femoral anteversion, following three major parameters are required; the neck axis, the long axis, and the knee axis. Conventional methods on the basis of 2D images are ambiguous to determine these major axes. As the femur has a complex 3 dimensional structure, the 3 dimensional model should be applied for accurate and reliable measurement of femoral anteversion. In this thesis, we model femur and define three parameters. The neck axis is defined from the femoral head and neck model. The long axis is determined from the cylindrical model of the femoral shaft. The knee axis is also determined from the model of femoral condyles. According to the definition of the femoral anteversion, the femoral anteversion is efficiently estimated from these models. 20 specimens were tested by the conventional 2D imaging method and 3D imaging method witch was developed by authors and the new 3D modeling method. The study provides accurate, fast and human factor free measurement for femoral anteversion.

• Archives of Reconstructive Microsurgery
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• v.16 no.1
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• pp.1-5
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• 2007

The purpose of this article to evaluate the availability of the rectus femoris flap in Korean subjects. Material and Methods is that Cadaveric dissections were done on 51 femoral triangles of 26 cadevers. We measured the length of the direct head of rectus femoris from anterior superior iliac spine to patella upper pole, ASIS to lateral border of femoral nerve, and entry point of femoral nerve and vessel branches to rectus. Usually, there were three terminal branches to rectus femoris from the femoral nerve. The entry point of the first branch was at the proximal $17.5{\sim}31.4%$ portion of the rectus femoris. The second and the third branch entered at the proximal $22.5{\sim}40.7%$ and $26.3{\sim}42.3%$, respectively. The vessel entry was at $20.2{\sim}37.3%$. The length from ASIS to femoral nerve was $3.5{\sim}8.5\;cm$. Among the 51 rectus femoris muscles, 44 had one nutrient artery, and 7 had 2 nutrient arteries. The nutrient artery originated from the descending branch of the lateral femoral circumflex artery in 18(40.9%) cases, directly from the lateral femoral circumflex artery in 8(18.0%) cases, and from proximal(6 cases, 13.6%) and distal(12 cases, 27.3%) portion of the deep femoral artery. The average length of the nutrient artery was 29.8 mm and the width was 2.14 mm. The point where it meets the main feeding artery of the rectus femoris was $9.0{\sim}15.0\;cm$ from the ASIS. In all cases, the main artery's entrance was proximal to the first nerve branch. Conclusion is that rectus femoris has available data for functional flap.

• Journal of the Korean Society for Nondestructive Testing
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• v.31 no.5
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• pp.459-465
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• 2011

It has been reported that the femoral morphology has a major correlation to femoral neck fractures(FNF). Previous studies to analyze these correlations have relied on mechanical testing and finite element methods. However, these methods have not been widely applied to various femur samples and models. It is because of the availability of the samples from both patients and cadavers, and also of the geometric limitations in changing the shape of the models. In this study we analyzed femoral neck fractures using a parameterized femoral model that could provide flexibility in changing the geometry of the model for the wide applications of FNF analysis. With the parameterization a variety of models could be generated by changing four major dimensions: femoral head diameter(FHD), femoral neck diameter(FND), femoral neck length(FNL), and neck-shaft angle(NSA). We have performed FEA on the models to compute the stress distributions and reaction forces, and compare them with the data previously generated from mechanical testing. The analysis results indicate that the FND is significantly related with the FNF and the FHD is not significantly related with the FNF.

• The Korean Journal of Physiology
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• v.21 no.2
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• pp.211-223
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• 1987

Head-down tilt (HDT) at $-6^{\circ}$ has been commonly used as the experimental model in both man and animals to induce the blood shift toward the head or central protion of the body, demonstrating similar physiological effect encountered in the weightlessness in the orbital flight. There are few reports about the physiological response upon the cardiovascular regulatory system or the tolerance to the $(-6^{\circ})$ HDT within a relatively short period less than 1 hour. Therefore, the purpose of this study way to observe the effects of $-6^{\circ}$ HDT on cardiovascular system within 30 minutes and to evaluate early regulatory mechanism for simulated hypogravity. Ten mongrel dogs weighing 8-12 kg were anesthetized with the infusion of 1% ${\alpha}-chloralose$ (100 mg/kg) intravenously, and the postural changes were performed from the supine to the $-6^{\circ}$ head-down Position, then from the head-down to the supine (SUP), and each posture was maintained for 30 minutes. Blood flow $({\dot{Q}})$ through common carotid and femoral arteries were determined by the electromagnetic flowmeter. Mean arterial pressure (MAP), heart rate (HR), respiratory rate , and pH, $P_{O_2}$, $P_{CO_2}$ and hematocrit (Hct) of arterial and venous blood were also measured. The peripheral vascular resistance was calculated by dividing respective MAP values by ${\dot{Q}}$ through both sides of common carotid or femoral arteries. The concentration of plasma epinephrine and norepinephrine was determined by Peuler & Johnson's radioenzymatic method. The results are summarized as follows: In the initial 5 minutes in $-6^{\circ}$ HDT, HR was significantly (p<0.05) increased and MAP slightly decreased. Although ${\dot{Q}}$ and carotid peripheral artery resistance were not significantly changed, ${\dot{Q}}$ through femoral artery was diminished and femoral peripheral artery resistance was elevated. In the SUP, the initial changes of MAP and HR were increased (p<0.05), but those of ${\dot{Q}}$ and peripheral vascular resistance through both common carotid and femoral arteries were not significant. After 10 minutes of each postural change in both HDT and SUP, MAP was maintained almost equal to that of the level of pretilting control. During 60 minutes of both postural changes of HDT and SUP, $P_{O_2}$ and Hct were not changed significantly. However pH tended to increase slowly and $P_{CO_2}$ was gradually decreased. The pH and $P_{CO_2}$ seemed to be related to the increased respiratory rate. Plasma epinephrine concentration was not changed significantly and plasma norepinephrine concentration was slightly decreased in the course of HDT and also at 10 minutes of SUP. However these concentration changes were statistically insignificant. From these results, it may be concluded that the effect of $-6^{\circ}$ HDT for 30 minutes on the cardiovascular system and plasma catecholamine levels of the dog is minimum and it is suggestive that the cardiovascular regulatory mechanism, possibly mediated by so called gravity receptors including baroreceptor and volume receptor, has been properly and adequately operated.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.365-366
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• 2002

The sliding wear behavior of ultra high molecular weight polyethylene (UHMWPE) was examined on a novel low temperature degradation-free zirconia/alumina composite material and conventional alumina and zirconia ceramics used for femoral head in total hip joint replacement. The wear of UHMWPE pins against these ceramic disks was evaluated by performing linear reciprocal sliding and repeat pass rotational sliding tests for one million cycles in bovine serum. The weight loss of polyethylene against the novel low temperature degradation-free zirconia/alumina composite disks was much less than those against conventional ceramics for all tests. The mean weight loss of the polyethylene pins was more io the linear reciprocal sliding test than in the repeal pass rotational sliding lest for all kinds of disk materials. Neither the coherent transfer film nor the surface damage was observed on the surface of the novel zirconia/alumina composite disks during the test. The observed r,'stilts indicated that the wear of the polyethylene was closely related to contacting materials and kinematic motions. In conclusion, the novel zirconia/alumina composite leads the least wear of polyethylene among the tested ceramics and demonstrates the potential as lhe alternative materials for femoral head in total hip joint replacement.

• Journal of Korean Foot and Ankle Society
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• v.11 no.1
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• pp.111-114
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• 2007

Open calcaneal fracture with more than lateral half of bone loss and soft tissue defect occurred in 17 year-old male patient due to motor vehicle accident. Soft tissue defect included heel pad, peroneal tendon. Bone loss involved mainly most part of inferior tuberosity but not subtalar joint. Open dressing and debridement were done daily in operating room and antibiotics administration was started. After granulation tissue formed, femoral head allograft was performed and fixed with 6.0 mm screws to replace bone defect. Soft tissue defect was covered with latissimus dorsi musculocutaneous free flap. No sign of infection nor major osteolysis was observed in 15 months follow up period. Soft tissue defect was covered with latissimus dorsi musculocutaneous free flap.

• Journal of Veterinary Clinics
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• v.18 no.3
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• pp.243-248
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• 2001

Radiographic findings of degenerative joint disease (DJD) in the coxofemoral joints were studied in 108 dogs referred to Veterinary Medical Teaching Hospital, College of Veterinary Medicine, Seoul National University. Radiographic findings were identified with a extended ventrodorsal projection. Clinical signs such as pain in the affected joint, exercise intolerance, lameness, crepitation on flexion and extension of the joint and decreased range of motion, were shown in 40% and radiographic changes of bilateral coxofemoral joints were identified in 69% of a group of dogs. There are no sex predilections. Thirty-seven dogs were diagnosed as canine hip dysplasia (CHD; 10 cases), avascular necrosis of the femoral head (Legg-Calves-Perthes disease [LCPD]; 12 cases), fracture of the acetabulum (1 case), luxation(10 cases) and subluxation (15 cases), however, luxation and subluxation were identified in 11 dogs affected with CHD and LCPD. Causes of DJD in others (71case) were not identified. Radio-graphic findings identified included osteophyte formation at the attachment of the joint capsule (70%), sclerosis of the subchondral bone of the cranial acetabular edge (47%), remodeling of the femoral head (34%), thickening of the femoral neck(31%), perichondral osteophyte formation (31%), joint laxity (30%) and so on. All of the dogs diagnosed as CHD were large breed such as Retriever, Germain Shepherd, and Weimaraner and their age was under 1 year. This condition occurred bilaterally in 70% of affected animals. Dogs diagnosed as LCPD were young (under 1 year), small breed dogs. The incidence of LCPD is greater in Yorkshire Terrier, Miniature Pinscher and Poodle. This condition occurred unilaterally in 67% of affected animals. Clinical signs of dogs with unknown cause were shown in 15% and this condition occurred bilaterally in 75% of affected animals. Radiographic findings varied with patient's age and breed, however, the most common finding was osteophyte formation at the attachment of the joint capsule.

• IMMUNE NETWORK
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• v.22 no.3
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• pp.25.1-25.11
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• 2022

IL-34 can promote osteoclast differentiation and activation, which may contribute to steroid-induced osteonecrosis of the femoral head (ONFH). Animal model was constructed in both BALB/c and IL-34 deficient mice to detect the relative expression of inflammation cytokines. Micro-CT was utilized to reveal the internal structure. In vitro differentiated osteoclast was induced by culturing bone marrow-derived macrophages with IL-34 conditioned medium or M-CSF. The relative expression of pro-inflammation cytokines, osteoclast marker genes, and relevant pathways molecules was detected with quantitative real-time RT-PCR, ELISA, and Western blot. Up-regulated IL-34 expression could be detected in the serum of ONFH patients and femoral heads of ONFH mice. IL-34 deficient mice showed the resistance to ONFH induction with the up-regulated trabecular number, trabecular thickness, bone value fraction, and down-regulated trabecular separation. On the other hand, inflammatory cytokines, such as TNF-α, IFN-γ, IL-6, IL-12, IL-2, and IL-17A, showed diminished expression in IL-34 deficient ONFH induced mice. IL-34 alone or works in coordination with M-CSF to promote osteoclastogenesis and activate ERK, STAT3, and non-canonical NF-κB pathways. These data demonstrate that IL-34 can promote the differentiation of osteoclast through ERK, STAT3, and non-canonical NF-κB pathways to aggravate steroid-induced ONFH, and IL-34 can be considered as a treatment target.