Osteosarcoma is the most common primary bony malignancy and its survivorship has been progressed markedly through refined chemotherapy and surgery. But still there are many non-responders and analysis of prognostic factors may be helpful for them. Two hundred and sixty-six patients were enlisted between Mar, 1985 and Sep. 1994. Among them our inclusion criteria were: 1)primary, nonmetastatic classical osteosarcoma 2)extremity in location 3)no prior treatment at other institute and completed neoadjuvant chemotherapy and surgery according to our protocol. One hundred and eleven cases were eligible. Analyzed factors were:age, sex, location, tumor size, and pathologic response. Statistical methods were log-rank test for univariate and Cox's test for multivariate analysis. Male to female ratio was 69:42 with an average age of 17.2 years. Locations of tumor were distal femur 59, proximal tibia 29, and proximal humerus 8. Tumor size were measured by its maximal diameter and 48 cases were above 10cm and 47 cases were below 10cm. For pathologic response, 57 cases showed more than 90% and 54 cases were less than that. Limb salvage procedure was 101 cases and amputation was 10 cases and their local recurrence rate were 3.6%. Average follow-up period was 24(9-78.2) months and their final status was CDF 86, AWD 8, NED 5, and DOD 12 cases. In univariate study: type of operation(p=0.005), tumor size(p=0.005), and pathologic response(p=0.02) were significant variables. Pathologic response(p=0.03) and type of operation(p=0.01) were meaningful prognostic factors on multivariate analysis. But the latter result was interpreted as a bias, so pathologic response remained as a sole meaningful prognostic factor. More aggressive chemotherapy will be needed to improve the survival.

Resistance to combination chemotherapy remains challenge in the treatment of osteosarcoma. One of the mechanisms of multiple drug resistance is an increased expression of the multidrug resistance gene(mdr1). Expression of the P-glycoprotein(mdr-1 gene product) was studied immunohistochemically and the mdr-1 gene by in situ hybridization in 33 osteosarcomas relating to various prognostic factors. Thirty cases out of 33 osteosarcomas(90.9%) showed positive cytoplasmic reactions with P-glycoprotein and nineteen instances(57.6%) were strong positive(2+). The older(>20 years) and female patients revealed more intense immunohistochemical reactions rather than those of the younger and male patients. Osteoblastic and chondroblastic osteosarcomas revealed more strong immunohistochemical reactions compared to fibroblastic types. There were no significant staining differences between the type of bony involvement, Broder's grade and the presence of necrosis. On follow-up, the mean survival rate was decreased in the strong positive group, however, this was not statistically significant. In situ hybridization for mdr-1 gene revealed positive signals in 22 cases out of 29 osteosarcomas(75.9%). Chemotherapy was done in 15 cases out of 28 patients(53.6%). The results of immunohistochemistry and in situ hybridization were not correlated with the protocols for chemotherapy. However, this result should be confirmed by a larger scale study about mdr1 mRNA expression.

Prosthetic replacement is one of the most common methods of reconstruction after resection of malignant tumor around the knee. Gait analysis provides a relative objective data about the gait function of patients with prosthesis. The purpose of this study was to compare the gait pattern of the patients who underwent limb salvage surgery with prosthesis for distal femur and that of patients with prosthesis for proximal tibia. This study included ten patients (4 males, 6 females, mean age 22.7 years, range 14-36) who underwent a wide resection and Kotz hinged modular reconstruction prosthesis replacement and six normal adult(Control). The site of bone tumor was the distal femur (Group 1) in six patients and proximal tibia (Group 2) in 4 patients. The follow-up period ranged from 15 to 82 months (mean : 33 months). The evaluation consisted of clinical assessment, radiographic assessment, gait analysis using VICON 370 Motion Analysis System. The gait analysis included the linear parameters such as, walking velocity, cadence, step length, stride length, stance time, swing time, single support and double support time and the three-dimensional kinematics (joint rotation angle, velocity of joint rotation) of ankle, knee, hip and pelvis in sagittal, coronal and transverse plane. For the kinetic evaluation, the moment of force (unit: Nm/kg) and power (unit: Watt/kg) of ankle, knee and hip joint in sagittal, coronal and transverse plane. In the linear parameters, cadence, velocity, step time and single support were decreased in both group 1 and group 2 compared with control. Double support decreased in group 2 compared with control significantly(p<.05). In contrast to our hypothesis, there was no significant difference between group 1 and group 2. In Kinematics, we observed significant difference (p<.05) of decreased knee flexion in loading response (G2

본 서울위생병원 정형외과에서는 제 3 요추의 좌측 추궁판과 하 관절 돌기에서 발생하여 척수 압박 증상을 일으킨 골연골종 1례를 경험하였기에 문헌고찰과 함께 보고하는 바이다.

PURPOSE : For the reconstruction of large bone defect after tumor resection, it is possible to reuse the bone involved by tumor with some treatment to it. Several bone-reusing methods have been reported such as autoclaving, low-heat treatment(pasteurization) and intraoperative radiotherapy. We have used extracorporeally radiated autogenous bone graft for reconstruction after tumor resection, and analyzed the periods for junctional union, functional results and complications to know the indications of this method. METHODS : From Dec. 1993 to Sept. 1995, nine patients had taken autogenous bone graft with extracorporeal irradiation. Eight cases were osteosarcoma and 1 giant cell tumor. The graft sites were 5 in femur, 3 proximal tibia and 1 femur and tibia. Stage 3 was 1 case(GCT), Stage IIB 3 and Stage IIIB 5. After wide resection, surrounding soft tissue and intramedullary and extramedullary portion of the tumor were removed. Radiation was done in 5000cGy to the resected bone. Ender nails and bone cement were inserted and filled into the medulla to prevent fracture. RESULTS : Average follow-up period was 12.3(4 to 21) months. Average junctional union period in simple X-ray was 6.5 months in 4 cases. Average functional score following Enneking's criteria was 19(12-27). Complications were as follows ; condylar fractures and femur neck fracture in 4 cases, subluxation of the knee joint 3 and infection 1. Although local recurrence was detected in 1 case, the site of recurrence was not in the radiated bone but surrounding soft tissue. At final follow-up, no recurrence was found in one case(GCT), CDF 2, AWD 2, DOD 3, and died of chemotherapy related sepsis 1. CONCLUSIONS : Extracorporeally radiated bone autograft is considered to be a method for reconstruction of the large bone defect made by tumor resection, especially in the reconstruction around the joint.

The pasteurization of bone tumor shows necrosis of tumor tissue and it is used widely as one of the options of limb salvage operation. However malignant tumors of the extremities commonly involve major neurovascular structures and pasteurization of this structure will make limb salvage operation much easier and safer than autogenous vein graft or artificial vessel graft. So the purpose of this study is to evaluate that the pasteurization can be applied in the limb salvage surgery of malignant tumor involving major vessels by means of studying the patency of pasteurized femoral vessels of the dogs. The right femoral arteries of 5 to 7 mm in diameters and veins of 7 to 10 mm in diameters of five dogs were pasteurized with sterile $60^{\circ}C$ saline for 30 minutes. Contralateral femoral vessels were evaluated for the control study. After one month, the changes in the pasteurized femoral vessels were evaluated by physical examinations, femoral angiography, gross findings, and pathologic findings on the each side. One month after pasteurization, the pulse of the femoral and popliteal arteries was palpated with normal tone on the each side of the all five experimental animals, and there was no gross swelling or necrotic changes in the legs. Femoral angiography showed a good patency of femoral and popliteal arteries. On the gross examinations at time of sampling of the specimen for the pathologic examinations, there was a good patency of femoral artery and vein, and mild fibrous adhesion was noted around the pasteurized femoral vessels. On the pathologic examinations, the more fibrotic adhesion and neocapillarization were noted in the outer layer of adventitia of the pasteurized femoral arteries and veins than the control sides. The vascular lumina were also patent in all cases. With these results, we suggest that the malignant tumor of the extremity involving major vessels is possibly treated by the limb salvage operation using the pasteurization of the involved vessels.

During the last decade, the use of primary amputation has decreased, and a larger number of patients are being treated with resection and reconstruction with limb preservation. The advantage of chemotherapy, improvements in diagnostic imaging methods and newer techniques for reconstruction have made limb salvage an alternative to amputation for most patients with malignant bone tumor. Clinical results and functional results of the limb salvage operation of bone tumors treated at the Department of Orthopaedic Surgery, Guro Hospital, Korea university was reviewed. Eighteen bone tumors(seven giant cell tumors and eleven malignant bone tumors.) were studied over a period of five years. The limb salvage group included fourteen endoprothesis, two pasteurized autograft, one near total scapulectomy and one rotationplasty. Functional evaluation was performed according to the Enneking's modified system. The results were as followed; 1. At a mean follow-up of thirty two months (15-77 months), fourteen(83%) of the eighteen patients with limb salvage procedures had been continuously disease free. 2. There are no local recurrence but deep infection developed in two patients and three patients with distant metastasis. 3. Thirteen(87%) of the fifteen patients showed above 60% of functional results. 4. Fourteen(93%) of the fifteen patients were satisfied with the limb salvage procedures.