Expression Patterns of PTEN (Phosphatase and Tensin Homologue Deleted on Chromosome 10) in Osteosarcoma / 대한정형외과학회잡지

PURPOSE: To characterize PTEN gene alterations and their expressions during the development of osteosarcoma. MATERIALS AND METHODS: We studied the pattern of deletion, mutation and expression of PTEN in normal bone tissues, tumor samples of 22 patients of osteosarcoma, and 4 osteosarcoma cell lines (HOS, U2-OS, MG-63 and Saos-2). The tissue was analyzed for deletion and mutational inactivation of PTEN by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and direct sequence analysis, and examined for abnormalities in expression by immunohistochemistry. RESULTS: In this study, neither mutation nor deletion of PTEN was found. Expression of PTEN protein was increased, without deletion or mutation of the PTEN gene, in 22 patients of osteosarcoma and in 4 osteosarcoma cell lines. Nuclear staining was more intense than the cytoplasmic staining in normal bone tissues and osteosarcoma cell lines, but in osteosarcoma tissues PTEN was expressed mainly in the cyto-plasm. CONCLUSION: These results suggest that abnormal expressions of PTEN by differential compartmentalization may play a role in the development and progression of osteosarcoma, instead of genetic alterations of PTEN.

Evaluation of Functional Outcomes and Quality of Life Assessments in Patients with Malignant Tumors of the Musculoskeletal System / 대한정형외과학회잡지

PURPOSE: This study was designed to validate the functional evaluation system after surgery of malignant musculoskeletal tumors by ISOLS (International Symposium On Limb Salvage). MATERIALS AND METHODS: The reliability, content and criterion validities of the ISOLS system were investigated using the Nottingham Health Profile, the Medical Outcome Study 36-item Short-Form Health survey and the EuroQol instrument to measure the quality of life of patients with malignant musculoskeletal tumors. Forty nine patients were evaluated Osteosarcoma around knee joint was most commonly. Prosthetic reconstruction was performed in 55.1%. RESULTS: In content validity analysis, no social and psychological domains was found in ISOLS and the domains for functions of the lower extremities had a strong Cronbach's coefficient (0.88). ISOLS exhibited strong correlation in criterion validity. Convergent validity was good but the discriminative validity was poor. ISOLS has reliability with a strong correlation with other golden standard outcome measures. CONCLUSION: Overall reliability and validity of the ISOLS system appeared to be acceptable. However, this system may need further development of its appropriate domains to evaluate the quality of life in patients with malignant musculoskeletal tumors.

The Cytotoxic Effect of Methotrexate Loaded Bone Cement on the Osteosarcoma Cell Lines / 대한정형외과학회잡지

PURPOSE: The purpose of this study is to investigate the feasibility of bone cement as a vehicle of methotrexate, and potent chemotherapeutical drugs for osteosarcoma, and to evaluate the cytotoxic effect of the eluted methotrexate on osteosarcoma cells. MATERIALS AND METHODS: Various amounts of methotrexate were mixed with bone cement to make pellets containing corresponding dosages of methotrexate. The elution experiment was performed. The amount and the rate of elution, the duration of elution, and the elution pattern were checked daily by measuring the absorbance for four weeks. The cytotoxic effect of the eluted methotrexate on SaOS2 and MG63 osteosarcoma cells was examined by MTT assay, and the results were analyzed according to the concentration of the methotrexate and time. RESULTS: The amount of eluted methotrexate was the greatest during the first day, then the amount decreased rapidly until the end of the first week, reaching its plateau in the third week. The amount of eluted methotrexate from the pellets averaged 6.1% during the first week, and 9.6% during the four weeks. The concentration of eluted methotrexate was 130 to 10,000 times higher than the minimum inhibitory concentration throughout the experimental period. As a result of the cytotoxic effect of the eluted methotrexate, the number of viable tumor cells decreased significantly after 72 hours of exposure, and the viable cells were hardly seen after one week. CONCLUSIONS: In conclusion, the methotrexate eluted from the bone cement has sufficient cytotoxic effect on osteosarcoma cells in vitro, and the results suggest that local chemotherapy using a methotrexate loaded cement may be applicable in the management of osteosarcoma after evaluation of its long-term effect.

The Results of Endoprosthetic Reconstruction for Tumors of the Distal Tibia and Fibula / 대한정형외과학회잡지

PURPOSE: We performed this study in order to analyze the surgical and oncological results of prosthetic reconstruction of the distal tibial or fibular tumors and estimate the effectiveness of this kind of reconstruction in that region. MATERIALS AND METHODS: The data of six patients who underwent prosthetic reconstruction for the distal tibial or fibular tumors were reviewed. Diagnoses were osteosarcoma in four patients, parosteal osteosarcoma in one and recurrent giant cell tumor in one. Five tumors occurred at the distal tibia and one at the distal fibula. The age was 26 years (11-46 years). We performed resection and reconstruction using custom made tumor prosthesis. The mean follow-up duration was 5.8 years. RESULTS: Average functional score by ISOLS evaluation system was 24.2 (80.5%). All of the patients were continuously disease free at the final follow up. The complications were one wound infection and one collapse of talar component. CONCLUSION: The results of prosthetic reconstruction in the ankle regions demonstrated acceptable medium term results. It may be considered an option for malignant tumors of the distal tibia or the distal fibula in selected patients.

Immunohistochemical Expression of p53 Protein and P-glycoprotein and its Prognostic Significance in Osteosarcoma / 대한정형외과학회잡지

PURPOSE: The principal cause of treatment failure in osteosarcoma is drug resistance. Multidrug resistance (MDR), mediated by P-glycoprotein (P-gp), is an in vitro phenomenon, resulting in becoming cross-resistant to structurally unrelated drugs. P-gp expression was related to drug resistance, prognosis and recurrence in osteosarcoma. p53 gene regulates genomic stability. Mutant p53 protein causes loss of tumor suppression. Co-expression of mutant p53 protein and P-gp was related to short survival, malignancy and drug resistance in malignant tumors. Wild type p53 protein in SaOS-2 cell line down-regulates the transcription of mdr1 gene. The purpose of this study was to evaluate the expression of mutant p53 protein and P-gp in osteosarcoma and its prognostic significance. MATERIALS AND METHODS: Fifty-two archival pathologic tissues were examined with immunohisto-chemistry. Positive expression was defined if more than 10% of tumor cells were stained. RESULTS: Expression rate of mutant p53 protein was 63% and rate of P-gp was 35%. Correlation between mutant p53 protein and P-gp expression was significant (P=0.0008). Co-expression of mutant p53 protein and P-gp was the strongest prognostic factor for shorter survival by multivariate analysis (P=0.0004). CONCLUSIONS: Nuclear accumulation of mutant p53 protein was significantly related to P-gp expression in osteosarcoma, Co-expression of mutant p53 protein and P-gp is an independent unfavorable prognostic factor in osteosarcoma

Treatment Result of Pediatric Osteosarcoma with Intraarterial Cisplatin / 대한암학회지

PURPOSE: This study was performed to determine the outcome after treatment of osteosarcoma with intraarterial cisplatin as a preoperative chematherapy regimen. MATERIALS AND METHODS: Twenty five patients with extremity osteosarcoma were treated with intraarterial cisplatin at Seoul National University Children's Hospital from January 1987 to April 1996. The dose of cisplatin was 130 mg/m2 and three to six courses were repeated two- to three-week intervals, Systemic doxorubicin was added to six of these patients. This was followed by surgical resection(limb salvage or amputation) and postoperative adjuvant chemotherapy. RESULTS: Limb-salvage was possible in twenty of these twenty five patients. Pulmonary metastasis was present in five patients at diagnosis and developed later in three patients. In six patients treated with systemic doxorubicin, pulmonary metastasis was absent at diagnosis and during follow-up period. Local recurrence after limb salvage was occurred in one patient and treated with amputation and systemic chemotherapy. Seven patients died from pulmonary metastssis and one from unknown cause. The follow-up duration of these patients was three to eighty eight months(median twenty two months) and the overall five-year survival and event free survival rate were 62.1% and 57.5%, respectively. CONCLUSION: These data demonstrate that intraarterial cisplatin can be used as an effective regimen preoperatively for pediatric patients with extremity osteosarcoma. The combined use of systemic doxorubicin is expected to improve survival in patients with pulmonary metastasis.

The effect of Autoclaved and Low Heat - treated Autogenous Bone Grafting on the Osteosynthesis in Rabbit / 대한정형외과학회잡지

Heat-treated autogenous bone graft has been utilized in the cases with large hone defects associated with tumors, chronic osteomyelitis, and trauma. Conventional autoclaved autogenous bone grafting, however, has inherent disadvantages that included decreased biomechanical strength, and loss of osteogenesity. In contrast, despite devitalizing the tumor cells, low heat-treatment can render autogenous hone grafts to retain better biomechanical strength as well as to preserve osteogenesity by avoiding destruction of hone morphogenetic protein. To investigate biomechanical strength and osteogenesity of heat-treated autogenous bone grafts, rahbits were classified into three groups: groupl, in-situ implantation of autogenous graft in the diaphyseal defect of the tibia without any heat treatment; group 2, reimplantation of graft after low heattreatment; group 3, reimplantation of graft after autoclaving. Radiological, histological, and scintigraphic examination were performed postoperativeIy at 2nd, 4th, 6th, 9th, 12th weeks. And biomechanical test was performed postoperatively at 6th, 9th, 12th weeks. Biomechanical test revealed that there were no statistical differences among three groups at 6th week and 9th week. However, at 12th week postoperatively, there were significant differences between group 2 and group 3, and between group 1 and group 3. Radiological and histological examinations showed that new bone formation started earlier in groups l and 2, compared to group 3. Also bone remodeling was advanced in group I and 2, com- pored to group 3. Scintigraphically, the increase of 99mTc-MDP uptake was delayed in group3, compared to group l and 2. Based upon above findings, it was concluded that low heat-treated autogenous bone grafting was hetter than autoclaved autogenous bone grafting in promoting bone healing with retained biomechanical strength.

The Clinical Results of Primary Cementless Total Hip Arthroplasties Using Omnifit Microstructured System: A Five-Year Clinical Follow-Up Study and Roentgenographic Analysis / 대한정형외과학회잡지

We reviewed 64 primary cementless porous-coated total hip arthroplasties using Omnifit Microstructured system (Osteonics, Allendale, New Jersey, U.S.A.). They were followed up for an average of 6 years (range, 5 years to 7 years and 11 months). The average Harris score was improved from 60.8 preoperatively to 86.2 postoperatively. The results were excellent in 3i cases(48.4%), good in 22 cases(34.4%), fair in 7 cases(I0.9%) and poor in 4 cases(6.3%). According to the last t'ollow-up radiologic findings, 61 cases(95.3%) were considered to he stable bony fixation and 3 cases(4.7%) to he stahle fibrous fixation. Neither unstahle fixation nor loosening of component was ohserved. But osteolysis was occured in 32 cases(50.0%) around prosthetic stem and in l6 cases(25.0%) around prosthetic cup. The mean linear wear of polyethylene insert was 1.46mm(range, 0.1 mm to 5.83mm). the linear wear rate was 0.23mm/year (range, 0.02mm/year to 0.81mm/year) and the excessive wear more than 2mm was ohserved in 15 cases. Reoperation was required in 18 cases(28. l%) after followup of 6 years (range, 4 years and 3 months to 7 years and 2 months); 11 had been reoperated and 7 were awaiting reoperation. The causes of reoperation were osteolysis and excessive polyethylene wear (more than 2mm) in 15 cases and osteolysis only in 3 cases. The result of primary cementless porous-coated total hip arthroplasties using Omnifit Microstructured system was acceptahle up to 5 years, but then increasing reoperation appeared to he due to polyethylene wear and osteolysis. Therefore, the routine follow-up of cementless porous-coated total hip arthroplasties is essential, especially after 5 years in order to detect and manage such prohlems early. And the modification in materials suhstituting metal-on-polyethylene articulation is required to reduce them.

Surgical Treatment of the Metastatic Tumors of the Femur / 대한정형외과학회잡지

Metastasis to bone with destruction of the skeletal system is a common problem in old patients with malignancy. Destruction of the musculoskeletal system poses major problems for the patients, including uncontrollable pain, forced immmobilization, pathologic fracture and hypercalcemia. The purpose of this study is to evaluate the effectiveness of surgical treatment and to suggest treatment guidelines for impending or established pathologic fractures due to metastasis of the femur. Between 1985 and 1995, thirty six patients who had pathologic or impending fractures in the femur underwent surgical treatment. The indications of surgery for pathologic fractures are 1) the possibility of survival time more than three months, 2) more benefits of sungical treatment than those of conservative treatment, 3) the possibility of rigid internal fixation, 4) patient s general condition allowing surgery, and those in impending fractures are 1) cortical destruction more than 50% or lytic lesion more than 2.5cm. The method of surgery was excision of the tumor and rigid internal fixation to allow early ambulation with or without bone cement augmentation. The results were analyzed by three criteria, the performance status, pain relief and survival time. Pain relief more than Lots was achieved in 80.6% of patients according to the Kaiko's criteria. The performance status improved more than one grade in all patients except one who died of acute respiratory failure and the mean improvement was 1.8 grade by the Functional Classification of the New York Heart Association. Postoperatively, most of the patients had only slight to moderate limitation of physical activities and felt comfortable at rest and ordinary activities. The survival time was 20.9 months in patients with single metastasis and 10.2 months in patients with multiple metastases. But there was no statistical significance due to large deviation of survival time in each case. In summary, surgical stabilization of the pathologic lesion involving the femur provided definite improvement of quality of life including pain relief and early ambulation. In selected patients with single metastasis, low grade malignancy, or good performance status, postoperative survival time may be expected to be prolonged. More aggressive treatment for the metastatic lesion of the femur is suggested.

Results of Limb Salvage Surgery in Primary Malignant Bone Tumors / 대한정형외과학회잡지

Limb salvage operation in primary malignant bone tumors is increasing recently, according to the improvement of diagnostic methods, surgical technique and adjuvant chemotherapy. The purpose of this study is to obtain the interim results of survival rate and the functional grade of the limb in primary malignant bone tumors treated by limb salvage operation. Between 1985 to 1993, 63 primary malignant bone tumors treated by limb salvage operations. Tumor prosthesis arthroplasty was performed in 49 patients, resection arthrodesis in 9 patients, and IM nailing with cement molding in 5 patients. Autoclave autograft was combined in 2 patients. Adjuvant chemotherapy and postoperative radiotherapy were performed in selected patients. The average follow-up period was 50 months(ranged 12 months to 116 months). In the cases of osteosarcoma, estimated survival rate was 61.9% based on Kaplan-Meier survival plot. In the parosteal sarcoma, the survival rate was 87.5% and 80% in chondrosarcoma patients. According to functional grading by Enneking, 66% was excellent, 20% was good, 11% was fair and one patients was poor. Complications occurred in 16 patients:wound infection was developed in 6 patients, local recurrence in 4, peroneal nerve palsy in 2 patients and femoral stem loosening in 2 patients. Fracture in resection arthrodesis and pulmonary metastasis were also occurred. Reoperation was performed in 10 patients at average 31 months after initial operation. Revision tumor persthesis arthroplasty was performed in one patient due to local recurrence and in 2 patients due to femoral stem loosening. Three amputations were done due to recurrence of tumor. IM nailing with cement molding was performed in one patient due to deep infection and repeated arthrodesis was done in a fracture patients. Scheduled custom-made tumor prosthesis arthroplasty was performed within a year in 2 patients treated with IM nailing with cement molding. In conclusion, with the careful preoperative assessment, adjuvant chemotherapy and skillful surgical technique, limb salvage operation would provide the primary malignant bone tumor patients for longer survival and better quality of life.

Neurilemoma of Trunk and Extremities / 대한정형외과학회잡지

Neurilemoma is benign never-sheath tumor which has been described as painless mass and is usually discovered incidentally. It is the most common tumor of peripheral nerve origin and may arise in any nerve where Schwann cells occur. There are few domestic reports which were clinically evaluated in tens of cases of neurilemoma so far. We evaluated on the 56 cases of neurilemoma confined to the trunk and extremities, in the aspect of clinical characteristics, radiology, pathology, EMG, surgical treatment and postoperative results, who were surgically treated at the Department of Orthopedic Surgery of Seoul National University from 1984 to 1994. Among 56 patients, male were 29 and female were 27, and there was no sexual difference. The average age at surgical intervention was 46.4 years (16–83yrs) and 46.4% of patients were in the age of fourties and fifties. The anatomical locations of the tumors were as followed: upper extremities in 22(39%) cases, neck and supraclavicular area in 15(27%) cases, sacrum and lower extremities in 14(25%) cases and trunk in 5(9%) cases. Symptoms were palpable mass in 55 cases, local tenderness in 14, radiating pain in 11, pain in 10, paresthesia in 11, motor weakness in 2 cases. The average follow up period was 19.1 months(13–56 month). Median nerve was involved most frequently(14%), then ulnar nerve(11%). There was no cases which occurred in multiplicity or associated with neurofibromatosis. Marginal excision was done in 51 cases(91%), incisional biopsy only in 4 cases(7%), wide excision in 1 case. The size of the tumors in the longest axis was smaller than 2cm in 9 cases, between 2 and 4cm in 31 cases, between 4 and 6cm in 13 cases and more than 6cm in 3 cases. Malignant change or recurrence was not found in all cases.

Flowcytometric DNA Analysis of Osteosarcoma Cells / 대한정형외과학회잡지

Flowcytometry is a very important technique for the analysis of cell properties, with the advantages of simultaneous multiparameter analysis of large cell population in a short time. Recent advances in computer science and techniques in cell preparation and staining make it more valuable for the study of cell biology and its clinical application. This study was performed to establish the techniques of flowcytometry analysis of osteosarcoma cells, to evaluate the results of the characteristics of the DNA and specific cell cycle phase of osteosarcoma cells obtained by preparation of paraffin-embedded tissue blocks, and to analyze any possible difference between cell populations lacated apart from each other in the tumor mass for making a base for further clinical application. Paraffin-embedded tissue blocks were obtained from 10 cases of primary osteosarcoma, which had undergone amputation without chemotherapy or radiotherapy. Tissue blocks obtained from the most superficial and the deepest portions of the tumor mass from the skin surface were selected respectively in each cases. To evaluate the technique and results obtained, analysis of the whole sample were performed twice in a separate setting. Satisfactory DNA histogram was obtained from 14 of 20 tissue blocks, with the values of distribution in the specific cell cycle phases. DNA aneuploidy was found in 2 cases with a DNA index of 1.6 and 1.3, and no difference in DNA ploidy by the location in tumor mass. The S-phase and G2+M phase fraction were 13.2±8.5 and 6.2±3.1 respectively, reflecting the increased cell proliferation compared with normal cell population. There was no statistically significant difference of these values between superficial and deep portions, but the difference was 9.0±9.7 with a maximum of 26.6, much greater than the difference 3.3±3.6, between the first and second set of analysis. Flowcytometry is a very useful technique in the analysis of the DNA and cell cycle phase properties, and the characteristics of DNA and cell proliferation status of osteosarcoma cells were successfully evaluated by this technique. Unsatisfactory DNA histograms were thought to be the result of inappropriate samples. To adequately evaluate the changes in the tumor mass, standardization in obtaining tumor tissue about the location in the tumor mass is suggested for future studies with flowcytometry about the properties of tumor cells.

MR Imaging of Soft Tissue Hemangioma of the Extremity

PURPOSE: To analyse the MR imaging characteristics of the soft tissue hemagiomas of the extremity. MATERIALS AND METHODS: We retrospectively reviewed histopathologically proven 18 cases of hemangiomas of the extremity including 15 cavernous hemangiomas, 2 venous hemangiomas and 1 capillary hemangioma. The lesions were frequent in female and low extremity. We analyzed the site, extent, margin, signal intensity, enhancement pattern, the homogeniety of internal architecture, and abnormal vessels near the lesion. RESULTS: The extensive lesions involving multiple muscle and tissue layers were more frequent than localized lesions (12/18). Twelve cases had ill defined margin. In most cases, the lesion was heterogeneous mass composed of nodular and septal components. The nodular component showed intermediate signal intensity in T1WI and hign signal intensity in T2WI. The setal component showed mixed inconstant signal intensity. One case of capillary hemangioma showed relatively homogeneous signal intensity than cavernous hemangioma and the main portion of 2 venous hemangiomas had mutilple tubular signal voids. At least some portion of the lesion was enhanced in all enhanced cases. CONCLUSION: The soft tissue hemangiomas of the extremity showed characteristic MR findings and MRI would be an useful method in the diagnosis of the soft tissue hemangiomas of the extremity.

MR Imaging of Soft Tissue Hemangioma of the Extremity

PURPOSE: To analyse the MR imaging characteristics of the soft tissue hemagiomas of the extremity. MATERIALS AND METHODS: We retrospectively reviewed histopathologically proven 18 cases of hemangiomas of the extremity including 15 cavernous hemangiomas, 2 venous hemangiomas and 1 capillary hemangioma. The lesions were frequent in female and low extremity. We analyzed the site, extent, margin, signal intensity, enhancement pattern, the homogeniety of internal architecture, and abnormal vessels near the lesion. RESULTS: The extensive lesions involving multiple muscle and tissue layers were more frequent than localized lesions (12/18). Twelve cases had ill defined margin. In most cases, the lesion was heterogeneous mass composed of nodular and septal components. The nodular component showed intermediate signal intensity in T1WI and hign signal intensity in T2WI. The setal component showed mixed inconstant signal intensity. One case of capillary hemangioma showed relatively homogeneous signal intensity than cavernous hemangioma and the main portion of 2 venous hemangiomas had mutilple tubular signal voids. At least some portion of the lesion was enhanced in all enhanced cases. CONCLUSION: The soft tissue hemangiomas of the extremity showed characteristic MR findings and MRI would be an useful method in the diagnosis of the soft tissue hemangiomas of the extremity.

Percutaneous Needle Biopsy of Bony Lesions: Diagnostic Accuracy and Clinical Utility

PURPOSE: To evaluate the diagnostic accuracy and clinical utility of percutaneous needle biopsy of the bony lesions. MATERIALS AND METHODS: Among 100 consecutive patients who underwent percutaneous needle biopsy of bony lesions, 96 patients who were diagnosed ultimately by surgery, or by clinical and radiological follow-up over 6 months were reviewed in this study. Biopsy sites were in the long bones in 51, axial bones in 45. Twelve biopsies were performed under CT guidance and the remainder were guided under fluoroscopy. The categories for the suspected diagnosis included 25 primary malignant tumors, 21 benign tumors, 31 metastases, 13 infections, and 6 miscellaneous lesions. RESULTS: Of the 96 biopsies, 86(89.6%) were adequate for the diagnosis out of which 81 were ultimately confirmed as true-positive or true-negative with the overall diagnostic accuracy rate of 94.2%. Diagnostic accuracy according to the suspected diagnosis was 91.3% in primary malignant tumors, 90.3% in metastases, and 100% in infections, benign tumors, and miscellaneous lesions. Respective diagnostic yield was 90.3% in metastases, 84.6% in infections, 84% in primary malignant tumors, 71.4% in benign tumors, and 100% in miscellaneous lesions. Both diagnostic accuracy and diagnostic yield differed little with the lesion location. No complication was observed in our series. CONCLUSION: Percutaneous needle biopsy of bony lesion is a safe procedure, offering high diagnostic accuracy and high clinical utility.

Osteosarcoma-Thirteen-Year Experience / 대한정형외과학회잡지

Osteosarcoma is the most common primary malignant tumor in the orthopaedic field. Recently, the management of osteosarcoma was evolved in many aspects and the improved results were reported in many articles. The purpose of this study is to evaluate the changes of clinical findings and management modalities in osteosarcoma since 1980. We reviewed 127 osteosarcomas managed from 1980 to 1992. The Enneking surgical stage was as follows; stage I 12 cases, stage II 98 cases and stage III 17 cases. They were subclassified into classic(97 cases), parosteal(12 cases), telangiectatic(5 cases), secondary(4 cases), periosteal(2 cases), gnathic(2 cases), high grade surface(1 cases) and undetermined(4 cases). The disease-free survival rate was evaluated for the patients of stage II classic osteosarcomas treated with amputation(27 cases) or limb-salvage operation(23 cases), and average follow up period of them was 49 months. In 27 cases of amputation adjuvant chemotherapy was administered in 23 cases. And in 23 patients treated with limb-salvage operation, neoadjuvant and adjuvant chemotherapy were done in 19 cases and only adjuvant chemotherapy in 2 cases. The clinical changes since 1980 were as follows: (1) The mean duration from symptom onset to diagnosis was decreased gradually from 6.5 months(1980) to 3.1 months(1992). (2) The proportion of curative surgery was increased from 40%(1980) to 87%(1992) in stage I and II. (3) The proportion of limb-salvage operation was rapidly increased upto 88% since 1985. The 5 year disease-free survival rate of stage II classic osteosarcoma was 36% with amputation and 67% with limb-salvage operation.

Chondrosarcoma / 대한정형외과학회잡지

Recently there has been remarkable improvement in the treatment of chondrosarcoma, accompanied with the development of diagnostic tools, operative technique, replacement materials and designs, anticancer-chemotherapy and radiotherapy. In well-deferentiated chondrosarcom, wide excision is the only treatment required. Nevertheless, in dedifferentiated chondrosarcoma, anticancerchemotherapy or radiotherapy is usually recommended after the wide excision. From 1984 to 1994, 22 patients diagnosed as chondrosarcoma had been treated at Seoul National University Hospital. We analysed anatomic distributions, size, methods of treatment and their results. The avereage age was 38 years and 10 months(15 years 73 years) and the average follow-up period was 3 years and 10 months(1 year and 6 months

A 5- to 13-year Follow-up of High Tibial Osteotomy / 대한정형외과학회잡지

High tibial osteotomy is a satisfactory surgical method of treatment for knees with unicompartmental osteoarthritis and angular deformity. This procedure has been found to reiieve pain, improve function and delay the progress of the condition by realigning the joint and thereby shifting the line of weight-bearing to the compartment with preserved articular cartilage. We reviewed clinically and radiologically the long-term results of the high tibial osteotomy performed on 17 medially osteoarthritic knees in 15 patients at Seoul National University Hospital from October 1980 to June 1989. We excluded the cases whose medical records were not complete or the follow-up was less than 5 years. There were 14 females and 1 male, and the average age of the patients were 59 years(range, 50 to 67 years), and the mean follow-up period was 7.3 years(range, 5 to 13.1 years). The clinical results were evaluated using Insall knee-rating scale. Excellent or good result was obtained in 14 knees(82%) at 2- and 5-year follow-up and in 13 knees(76%) at the final follow-up evaluation. Preoperative mean varus angle was 6.6 degrees. Postoperative corrected tibiofemoral angle decreased with time; immediate postoperative and final follow-up valgus angles were 10.2 and 8.5 degrees respectively. The clinical results based on the valgus angle achieved immediately after operation was 75 points(below valgus 10 degrees), 84 points(valgus 10 to 14 degrees), and 76 points(above valgus 15 degrees). Preoperative radiologic stage of osteoarthritis was evaluated using modified Ahlback classification(range, stage I to IV). The knee rating score at the final follow-up was 82 points in grade I(5 knees), 80 points in grade II(6 knees), 77 points in grade III(5 knees) and 72 points in grade IV(1 knee) degenerative arthritis. This study revealed that the best results were seen in knees with preoperative grade I or II degenerative arthritis and with 10 to 14 degrees of valgus immediately after osteotomy. Although there were some deterioration of clinical results and loss of correction with time after osteotomy, we concluded that appropriate selection of patients and careful surgical technique will provide good to excellent long-term results of high tibial osteotomy.

Effect of Stay-suture on Peripheral Nerve Tension / 대한정형외과학회잡지

The purpose of this study is to confirm the effectiveness of stay-suture which is commonly used in the procedure of end to end anastomosis, to find out general biomechanical properties of peripheral nerve with gradual stretching and to evaluate the histological difference after breakage of the nerve. The sciatic nerves of adult rabbits were excised and they were grouped by I and II. Group I was composed of 14 normal sciatic nerves and group II, 14 sciatic nerves sutured with 5-0 nylon after transection. They were stretched on the "Instron" universal testing machine at a constant rate of 200mm/min until breakage took place and the results were compared. The mean maximal tensile strength was 13.6N in group I and 2.1N in group II, representing about one seventh value. The mean ultimate tensile strength was 4.2MPa in group I and 0.9MPa in group II, representing about one fifth value. In load-elongation curve of group I, viscoelastic property was noted as all other biological tissues have. The mean modulus of elasticity was 19 in normal sciatic nerves, which is somewhat lower value than other tissues, indicating superior elastic property of peripheral nerves. Transverse histologic examination showed that epineurium lost its continuity earlier than perineurium, implying perineurium is a more resistant structure than epineurium. However, to confirm this, it is thought to be necessary to examine the nerves serially during distraction at each different status. In conclusion, stay-suture provided about one fifth of ultimate tensile stress, implying its usefullness of resisting excessive tension in end to end anastomosis of peripheral nerves. Normal sciatic nerves showed viscoelastic property with mean modulus of elasticity of 19.

Limb / 대한정형외과학회잡지

Tumors involving the proximal humerus confront the surgeon with the problem of both eradicating the osseous lesions and restoring shoulder joint function. This problem is magnified because of the biomechanical complexity of the shoulder, its anatomic configuration, and its inherent lack of stabillity. With the increased interest in limb-sparing resection for lesions in the area, efforts are being made to improve the reconstructive techniques. These include leaving a flail shoulder, an being made to improve the reconstructive techniques. These include leaving a flail shoulder, an arthrodesis using intercalery graft between the scapula and the remaining humerus, or if the glenoid is preserved, an arthroplasy. From January 1984 to December 1993, 23 patients with a malignant or locally aggressive bone tumor in the proximal humerus were treated by limb-sparing surgery in Seoul National University Hospital. Histologic diagnosis included osteosarcoma(6), chondrosarcoma(2), Ewing's sarcoma(1), metastatic bone tumor(11), and recurred giant cell tumor(3). Options for reconstruction following limb-sparing resection in our cases were 10 prosthetic arthroplasties, 3 arthrodeses with an living fibula graft, and 10 arthroplasties with intramedullary nailing and cementization. We performed a retrospective analysis in view of tumor eradication and performance status with modified functional evaluation system of Musculoskeletal tumor Society. In 7 cases(74%), good or fair performance status was acquired with average 3.6 years follow-up(6 months-11 years). Each option for reconstruction resulted in relatively good outcome but rather better result was acquired in giant cell tumor and chondrosarcoma. Estimated survival rates by Kaplan-Meier's method, 5 year survival rate was 81% in primary malignant bone tumors(12), 76% in stage Ⅱ B malignancies(5) with 4 years and 4 months follow-up. There was no regional recurrence in primary malignant bone tumors but there were three cases in which distant pulmonary metastases were found in follow-up. Complicationss were one soft tissue infection, two nonunions in arthrodesis with a living fibula graft and one dislodgement of prosthesis in prosthetic arthroplasty. In summary, each option for limb-sparing surgery in malignant bone tumor of proximal humerus might result in rather satisfactory outcome in performance and survival rate when effective preoperative and postoperative chemotherapy were performed in adequately selected cases.