• Journal of Yeungnam Medical Science
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• v.7 no.1
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• pp.81-93
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• 1990

The author fractographically analyized the cause of metal failure(the first time this procedure has been used for this metal failure)and also analyized it clinically. In this study, I selected eight cases which have been analyized fractographically. In all these cases, the analysis was done after treatment of metal failure of implants internally fixed to femur shaft fractures at the Department of Orthopedic Surgery, Yeung-Nam University Hospital during the six year period from May 1983 to September 1989. 1. Metal failure occured in five dynamic-compression plates, one Jewett nail, one screw in Rowe plate, and one interlocking nail. 2. The clinical cause of metal failure was deficiency of medial butress in five cases, incorrect position of implant in one case, and incorrect selection of implant in two cases. 3. The time interval between internal fixation and metal failure was four months in one case, between five months to twelve months in six cases, three years in one case. 4. The fractographically analytical cause of metal failure was ; first, impact failure, one case, second, fatigue failure, six cases, machining mark(stress liser), four cases type : low consistent cyclic fatigue failure irregular cyclic fatigue failure third, stress corrosion crack, one case. 5. 316L Stainless Steel has good resistance to corrosion. However, when its peculiar surface film is destroyed by fretting, it shows pitting corrosion. This is, perhaps, the main cause of metal failure. 6. It is possible that mechanical injury occured in implants during the manufacturing of implants or that making a screw hole is the main cause of metal failure.

• 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.

• Journal of Korean Tunnelling and Underground Space Association
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• v.10 no.3
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• pp.303-312
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• 2008

Multi-axial compression tests have been frequently adopted for the evaluation of material properties of rock cores and rock fracture model tests. Special care has to be applied on the boundary condition between the specimen and loading platen to draw the precise test results of the multi-axial compression tests. With the use of dry steel platen, the stress rotation will occur, due to the frictional restraint from the boundary between the specimen and loading platen. The restraint will deviate the expected test results under the conditions of the given external pressures. Various methods have been applied to reduce the side restraint along the specimen/loading platen interface. The steel brush type loading platen is one example of the attempts. In this paper, a new type of loading platen is introduced to overcome the limitation caused by the use of the brush type loading platen, which requires some internal space for the installation of the brushes. The new type of loading platen, roller supported steel piston type loading platen. is constituted of shot steel pistons which have sufficient stiffness to deliver the external pressure and the shaft type roller installed at the rear of the pistons. The pistons are designed to follow the local deformation of the specimens. In this paper, structural details of the loading platen are presented and frictional and biaxial compression tests results are shown to verify the required functions of the loading platen. Furthermore, calibration process is followed by a comparison between the test results and numerical analyses.

• Archives of Reconstructive Microsurgery
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• v.8 no.2
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• pp.176-183
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• 1999

Chronic osteomyelitis have been treated with wound dressing and antibiotics therapy often results in healing but foul odor pus discharges from the fibrotic soft tissues reactivates and requires appropriate control of the infection. Debridement of the wound, curettage and sequestrectomy, bone graft and immediate free flap transplantation is the curative protocol for the chronic osteomyelitis in the lower extremity. Authors have treated 7 cases of chronic osteomyelitis in the lower extremity with microsurgical free tissue transplantation at Department of Orthopedic Surgery, Chonbuk National University Hospital from December 1993 through February 1998. The results are as follows. 1. The chronic osteomyelitis occurred in tibial shaft in 4 cases, in calcaneus 2 cases and in femur 1 case. 2. Duration of the chronic osteomyelitis was at average 31.6 years. 3. Squamous cell carcinoma in the surrounding fibrotic tissue was biopsied in 1 case. 4. 4 cases had no trauma and occurred through hematogenous infection and 3 cases had fracture trauma. 5. Wound debridement and immediate free muscle transplantation had done in 5 cases and wound debridement, sequestrectomy and immediate free muscle transplantation in 2 cases. 6. Rectus abdominis muscle transplantation had peformed in 4 cases(57.1%), latissimus dorsi mucle 1 case(14.3%), latissimus dorsi myocutaneous 1 case(14.3%) and gracilis 1 case (14.3%). 6 cases of 7 were success(85.7%). 7. 1 case of failed latissimus dorsi musculocutaneous flap in thigh had done above knee amputation and 1 case of chronic posttraumatic osteoarthritis of the ankle joint had done below knee amputation at other hospital.

• The Journal of the Korean bone and joint tumor society
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• v.16 no.2
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• pp.80-86
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• 2010

Purpose: The skeleton is commonly affected by metastatic cancer. The purpose of this study was to evaluate the results of treating metastatic pathologic fractures in lower extremities using locking plates. Materials and Methods: Between 2004 and 2010, we evaluated 12 patients (13 cases) of metastatic pathologic fractures in lower extremities, treated with the locking plate. Mean patient age was 62.2 years (range, 50-81 years), the locations of the fractures were; proximal femur in 2 cases, femoral mid-shaft in 3, distal femur in 3, proximal tibia in 4, and distal tibia in 1 case. The interval to wheelchair ambulation, pain relief and complications were evaluated. Additionally, we assessed operation time and postoperative blood loss. Results: Mean time from operation to wheelchair ambulation was 3.2 days (range, 1-6 days). Mean VAS scores improved from a preoperative score of 8.1 points (range, 7-9 points) to a score of 2.7 points (range, 2-4 points) at 1 week postoperatively. No early complications associated with surgery were encountered. Mean operation time was 88.4 minutes (range, 70-105 minutes), and mean postoperative blood loss was 246.5 ml (range, 130-320 ml). Conclusion: Internal fixation of metastatic pathologic fractures using a locking plate in the lower extremity can be an effective treatment option in the meta- or diaphyseal area of long bones with massive bony destruction or poor bone stock by offering early ambulation, pain relief and low postoperative complications.

• The Journal of the Korean bone and joint tumor society
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• v.1 no.2
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• pp.154-163
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• 1995

With the development of anticancer chemotherapy and improved radiographic imaging studies, limb salvage operation became possible in the treatment of malignant and aggressive benign tumors. High grade sarcomas of the shoulder or the upper extremity can be surgically treated with a forequarter amputation, shoulder disarticulation or limb salvage surgery such as Tikhoff-Linberg procedure, segmental resection and replacement with endoprosthesis, segmental resection and replantation, or segmental resection and free vascularized bone graft. Among them the limb salvage surgery showed not only preservation of the remained upper extremity but also the excellent functional results. When comparing amputation and limb salvage operation while performing anticancer chemotherapy in both cases, 5 year survival rate, local recurrence, and distant metastasis did not show much difference. We studied 13 cases of limb salvage for the malignant and aggressive benign bone tumor of the upper extremity from March 1986 to December 1993 at Severance hospital. The summarized results were as follows. 1. There were 21 cases of malignant bone tumors and 5 cases of benign aggressive ones. 2. Of the 26 cases of malignant and benign aggressive bone tumors, limb salvage procedures such as Tikhoff-Linberg operation(8 cases), endoprosthetic replacement(2 cases), segmental resection and replantation(2 cases), and segmental resection and free vascularized fibular graft(l case) were done in 13 cases. 3. In 13 patient on whom the limb salvage procedure was performed, there were 3 osteosarcomas, 4 chondrosarcomas, 3 giant cell tumors, 1 Ewing's sarcoma, 1 leiomyosarcoma and 1 chondroblastoma. 4. In 13 patients, there was no local recurrence nor distant metastasis except one who had a segmental resection of the entire humerus part including glenoid and then postoperative anticancer chemotherapy for the treatment of the Ewing's sarcoma of the entire shaft of the humerus with pathological fracture. Local recurrence occurred 2 years and 6 months postoperatively in this Ewing's sarcoma patient, so forequarter amputation was performed and the irradiation and the anticancer chemontherapy were performed, but multiple bony metastasis developed and died of the disease 22 months after local recurrence. 5. The patients were followed-up for I year to 7 years and 5 months(average 4 years 5 months). 6. In 8 cases in which Tikhoff-Linberg procedure was performed, the function of the hand was almost normal. 7. Segmental resection and endoprosthetic replacement was performed in 2 cases, and the function of the remained upper extremity was good with no evidence of aseptic loosening or nerve palsy. 8. In 1 case of segmental resection and free vascularized fibular graft for the patient of the chon drosarcoma in the humerus, the function of the shoulder, elbow and hand was nearly normal. 9. In I case of leiomyosarcoma which involved both forearm muscles and bone near wrist joint, segmental resection and replantation was performed, and the patient has useful hand function.