• Proceedings of the KOSOMBE Conference
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• v.1996 no.11
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• pp.349-350
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• 1996

Using FEM, we analyzed the stress changes on early osteonecrosis of femoral head as the necrotic area increases. A 3D FEM model of proximal femur was made from the CT scam data of fresh frozen adult proximal femur with the material properties from literature. The model consisted of 5994 elements and 5275 nodes. FE analyses were peformed using MSC/NASTRAN. At normal states, stress transmission is mainly along the primary compression trabeculae(PCT). Until 60% involvement of PCT with necrotic lesion, stress transmission is still along the remained PCT. When the PCT involvement is from 60% to 85%, stress transmission is along the PCT and margin of the necrotic lesion. When involvement is more than 85%, stress is mostly transferred to posterior part of femoral head.

• Journal of the Korean Orthopaedic Association
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• v.54 no.6
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• pp.567-573
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• 2019

Slipped capital femoral epiphysis (SCFE) is a rare disorder of the proximal femur in adolescents. The pathogenesis of SCFE is unclear, but it is believed to be the result of a mechanical insufficiency of the proximal femur physis. SCFE appears to caused by mechanical, endocrinal, and immunological abnormalities. Few cases have reported the SCFE associated with endocrine disorder in the domestic literature, particularly in patients over 20 years old. This paper reports two cases of SCFE associated with hypopituitarism in adults over 20 years old.

• Structural Engineering and Mechanics
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• v.72 no.2
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• pp.191-201
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• 2019

Finite element analysis is one of the most used tools for studying femoral neck fracture. Nerveless, consensus concerning either the choice of material characteristics, damage law and /or geometric models (linear on nonlinear) remains unreached. In this work, we propose a numerical quasi-brittle damage model to describe the behavior of the proximal femur associated with two methods to evaluate the Young modulus. Eight proximal femur finite elements models were constructed from CT scan data (4 donors: 3 women; 1 man). The numerical computations showed a good agreement between the numerical curves (load - displacement) and the experimental ones. A very encouraging result is obtained when a comparison is made between the computed fracture loads and the experimental ones ($R^2=0.825$, Relative error =6.49%). All specific numerical computation provided very fair qualitative matches with the fracture patterns for the sideway fall simulation. Finally, the comparative study based on 32 simulations adopting linear and nonlinear meshing led to the conclusion that the quantitatively results are improved when a nonlinear mesh is used.

• 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.

• Journal of Biomedical Engineering Research
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• v.24 no.3
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• pp.233-239
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• 2003

Falling related injuries are categorized as the most serious and common medical problems experienced by the elderly, hip joint fracture, one of the most serious consequences of falling in the elderly, occurs in only about 1% of falling. Nevertheless, hip fracture accounts for a considerable part of the disability, death, and medical costs associated with falling. In this study, we considered the impact angle and displacement rate in falling as another factor affecting femoral strength. Using a fresh-frozen human femur, we developed system to simulate the falling condition and then conducted the experiments changing the impact angle (0$^{\circ}$, 15$^{\circ}$, 30$^{\circ}$) of proximal femur. Also, in order to analyze the relative risk due to falling to normal situation in proximal femur, we did the static test simulating the two-legged stance condition. The results showed that the change in impact angle affected the strain distribution in proximal femur, and that a large deformation in femoral neck than in other sites. Furthermore despite low impact velocity, a large deformation in proximal femur occurred in the impact test and different strain distribution was observed compare to the static case.

• Journal of Trauma and Injury
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• v.30 no.4
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• pp.247-252
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• 2017

Bone-grafting procedures are common in orthopedic trauma surgeries. There are only few reports on the morbidity after proximal tibia harvesting. Here, we report an experience of complication after proximal tibia harvesting while treating subtrochanteric femoral osteomyelitis.

• Journal of the Korean Orthopaedic Association
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• v.55 no.1
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• pp.62-70
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• 2020

Purpose: External tibia torsion and proximal tibial vara have been reported in severe varus deformed osteoarthritis, which is a tibio-femoral angle of more than 20°. The radiology measurements were compared with those of control group and the preoperative and follow-up radiology and clinical results were examined. Materials and Methods: From January 2007 to March 2016, 43 knees from 37 persons, who underwent total knee arthroplasty for a severe varus deformity of more than 20° on the tibio-femoral angle on the standing radiographs and had a follow-up period more than two years, were examined. The mean follow-up period was 45.7 months. The control group, who underwent conservative treatments, had Kellgren-Lawrence grade three osteoarthritis and a tibio-femoral angle of less than 3° varus. The external tibial torsion of enrolled patients and control group were estimated using the proximal tibio-fibular overlap length and the tibial torsion values on computed tomography. The proximal tibia vara was measured using the proximal tibial tilt angle. The preoperative and postoperative proximal tibio-fibular overlap length, tibial torsion value, proximal tibial tilt angle, and hospital for special surgery (HSS) score were evaluated. Results: The mean proximal tibio-fibular overlap length was 18.6 mm preoperatively and 11.2 mm (p=0.031) at the follow-up. The control group had a mean proximal tibio-fibular overlap length of 8.7 mm (p=0.024). The mean tibial torsion value was 13.8° preoperatively and 14.0° (p=0.489) at the follow-up. The control group had a mean tibial torsion value of 21.9° (p=0.012). The mean proximal tibial tilt angle was 12.2° preoperatively and 0° (p<0.01) at the follow-up. The control group had a mean proximal tilt angle of 1.2° (p<0.01). The preoperative tibiofemoral angle and mechanical axis deviation were corrected from preoperative 28.3° and medial 68.4 mm to postoperative 0.7° and medial 3.5 mm (p<0.01, p<0.01), respectively. The HSS scores increased from 34 points of preoperatively to 87 points at the last follow-up (p=0.028). Conclusion: Patients with advanced osteoarthritis with a severe varus deformity of more than 20° had significant increases in the external tibial torsion and varus of the proximal tibia. The tibial torsion value before and after surgery in the enrolled patients was not changed statistically, but good clinical results without complications were obtained.

• The Korean Journal of Nuclear Medicine Technology
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• v.27 no.1
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• pp.9-10
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• 2023

A 78-year-old female patient referred by the department of obstetrics and gynecology was recommended for orthopedic surgery because a cystic lesion was found in the left femoral proximal area in the bone mineral densitometry. CT scan and general X-ray performed in the orthopedic department found benign tumors later. Intra-medullary nail was operated. Curettage and bone graft were performed. Radiotechnologist is also important for the morphological observation of femur in the femoral BMD. It provides a lot of benefits to the patient.

• Journal of Veterinary Clinics
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• v.20 no.3
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• pp.328-333
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• 2003

This study was performed to investigate the effects of electrical stimulation on femoral fracture healing in dogs. Eight healthy dogs from 4 to 5 $\beta^3$ were used in this experiment. In the treatment group, anode and cathode were connected to proximal and distal site apart from the fracture line by 2 cm and electrical stimulation was applied to the fracture site for l5minutes by 2 V, 25 Hz and for a month. The control group was connected to electrostimulator as the treatment group, but no electrical stimulation was applied. Various parameters were evaluated including radiograph and serum levels of total-ALP(TALP), bone-ALP(BALP) and osteocalcin. The radiography revealed more rapid callus formation in the treatment group than in the control by about a week. The total-ALP levels of the treatment group were higher than those of the control group from the 2nd to the 24th day(p< 0.05). The bone-ALP levels of the treatment group were significantly higher than those of the control from the 2nd to the 24th day(p< 0.05). The bone-ALP/ total-ALP ratios of the treatment group were higher than those of control throughout this experiment but there were no significance. There were no significance in the osteocalcin levels between two groups. In conclusion, the electrical stimulation on femoral fracture site was effective for bone healing in dogs.

• The Korean Journal of Pain
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• v.31 no.4
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• pp.261-267
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• 2018

Background: To compare the effects of adding two different doses of dexamethasone on the duration and quality of the fascia iliaca block in patients undergoing proximal femoral fracture surgery. Methods: A total of 60 patients (age 18-70 years) undergoing proximal femoral nailing surgery under spinal anesthesia were given fascia iliaca block after random assignment to one of the two groups: Group H received an injection of levobupivacaine (0.5%) 28 ml with 2 ml (8 mg) dexamethasone, and Group L received an injection of levobupivacaine (0.5%) 28 ml with dexamethasone 1 ml (4 mg) with 1 ml normal saline. Assessment of the duration of analgesia and the total tramadol requirement over 48 hours were noted after a successful block. Results: The duration of analgesia was found to be significantly longer in Group H ($17.02{\pm}0.45h$) than in the Group L patients ($14.29{\pm}0.45h$) with a p-value of 0.000. Postoperative analgesic requirement (amount of tramadol in mg) was significantly higher in Group L (Q2: 200.0; IQR: 100.0, 200.0) as compared to Group H (Q2: 100.0; IQR: 100.0, 200.0) with a p-value of 0.034. No patient showed any sign of neurotoxicity. Conclusions: Dexamethasone, in a dose of 8 mg, is superior to 4 mg when used as an adjuvant with levobupivacaine in the FIB. Though both prolonged analgesia and were effective in reducing oral/intravenous analgesics, 8 mg dexamethasone can be recommended as a more efficacious adjuvant to local anesthetics in the FIB.