• The Journal of the Korean bone and joint tumor society
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• v.16 no.1
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• pp.1-7
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• 2010

Purpose: With advances in various treatment modalities, limb salvage surgery has been commonly used in osteosarcoma of extremities. An alternative method for skeletal reconstruction is reimplantation of the tumor bearing bone following extracorporeal irradiation (ECI). We report the long-term results of ECI autograft in aspect of the oncological and functional outcomes, and complications. Materials and Methods: We retrospectively reviewed 31 osteosarcoma patients who underwent reconstruction with ECI between July 1995 and January 2006. There were 24 males and 7 females with a mean age of 24 (7-74 years) and a mean follow-up of 117 months (17-177 months). Twenty-five cases were reconstructed with ECI autograft, 6 cases with ECI autograft-prosthesis composite. The pathologic subtypes were conventional in 29 cases, periosteal in 1 case, and parosteal in 1 case. The most common location of tumor was distal femur (15 cases) followed by humerus (3), proximal fibula (3) and proximal tibia (3). Musculoskeletal Tumor Society (MSTS) score was used for functional evaluation. The overall survival rate, local recurrence, complications were analyzed. Results: The overall survival rate was 80.6% and the disease-free survival rate was 64.5%. Five patients died of distant metastasis. One patient required above-knee amputation due to local recurrence. All of them, twenty-three complications occurred, which included nonunion in 7 cases, deep infection in 5 cases, joint instability in 4 cases, metal failure in 2 cases, Limb-length discrepancy (LLD) in 2 cases, periprosthetic fracture in 1 case, epiphyseal collapse in 1, local recurrence in 1 case. The mean MSTS functional score was 62.5%. Conclusion: Extracorporeal irradiated autograft can be achieved relatively good result in aspect of oncological and functional aspect, but is needed to be additional research about occurring many complications. The reconstruction with ECI after intercalary or fragmentary resection is effective reconstruction in aspect of oncological and functional result, complications.

• The Journal of the Korean bone and joint tumor society
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• v.8 no.1
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• pp.1-11
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• 2002

Purpose : We evaluated the radiological and functional results of prosthetic reconstruction for locally aggressive benign and malignant tumor in the lower extremity. Materials and Methods : Eighty eight patients were followed up for an average 76 months(22~174). We examined the survival rate of prosthesis, and evaluated the final result by MSTS functional score and ISOLS radiological implants evaluation system. They were statistically analyzed according to the age(<20 year vs. ${\geq}$20 year), fixation methods, amount of bony resection, chemotherapy, local recurrence, and presence of metastasis. Results : The 5 year prosthetic survival rates were 100% in the proximal femur, 83.3% in the distal femur, 81.9% in the proximal tibia. Mean total functional scores were 73.3%, 72%, 68.7%, respectively. In distal femur, the non-chemotherapeutic group was superior in the prosthetic survival rate. Recurrence or metastasis affected the functions in the distal femur and proximal tibia. In the radiological evaluation of the distal femur, older patients over 20 years of age and with cement fixation were superior in bone remodeling(p<0.05). Postoperative infection and radiological loosening were the main causes of the prosthetic failure. Conclusion : The prosthetic reconstruction in the lower extremity led to good clinical and radiological results. Amount of bony resection, chemotherapy, recurrence and metastasis seemed to influence the prosthetic survival, and long-term follow-up will be necessary to investigate more significant prognostic factors.

• Journal of Biomedical Engineering Research
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• v.25 no.4
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• pp.261-268
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• 2004

Osteoporosis is a clinical condition in which the amount of bone tissue is reduced and the likelihood of fracture is increased. It is known that the electrical property of the bone is related to its density, and, in particular, the electrical resistance of the bone decreases as the bone loss increases. This implies that the electrical property of bone may be an useful parameter to diagnose osteoporosis, provided that it can be readily measured. The study attempted to evaluate the electrical conductivity of bone using a technique of electrical impedance tomography (EIT). It nay not be easy in general to get an EIT for the bone due to the big difference (an order of 2) of electrical properties between the bone and the surrounding soft tissue. In the present study, we took an adaptive mesh regeneration technique originally developed for the detection of two phase boundaries and modified it to be able to reconstruct the electrical conductivity inside the boundary provided that the geometry of the boundary was given. Numerical simulation was carried out for a tibia phantom, circular cylindrical phantom (radius of 40 mm) inside of which there is an ellipsoidal homeogenous tibia bone (short and long radius are 17 mm and 15 mm, respectively) surrounded by the soft tissue. The bone was located in the 15 mm above from the center of the circular cross section of the phantom. The electrical conductivity of the soft tissue was set to be 4 mS/cm and varies from 0.01 to 1 ms/cm for the bone. The simulation considered measurement errors in order to look into its effects. The simulated results showed that, if the measurement error was maintained less than 5 %, the reconstructed electrical conductivity of the bone was within 10 % errors. The accuracy increased with the electrical conductivity of the bone, as expected. This indicates that the present technique provides more accurate information for osteoporotic bones. It should be noted that tile simulation is based on a simple two phase image for the bone and the surrounding soft tissue when its anatomical information is provided. Nevertheless, the study indicates the possibility that the EIT technique may be used as a new means to detect the bone loss leading to osteoporotic fractures.