Objective Through retrospective analysis of the thoracotomy of pulmonary metastases form osteogenic sarcomas in order to explore the related factors of prognosis and to improve the outcome of treatment.Methods From October1980to March2003,32cases with pulmonary metastases from sarcoma of bone were reviewed.62of thoractomy were performed for the patients,61of which were accomplished in the department of orthopaedics,and58operations were performed by the authors.There were32males and10females aging from11to61years with an average of 22.1years.The primary tumors of the patients were25oateosarcomas,3chondrosarcomas,2juxtacortical osteogenic sarcomas,and1each of fibrosarcoma and Ewings sarcoma.Of 32cases,21(65.6%)were treated with limb salvage,and11(34.4%)by am puta-tion.According to Enneking system,there wereⅡB in26andⅢB in5.25(78.1%)cases were bi lateral multiple metastases,6(18.8%)cases were unilateral solitary metastasis,and1(3.1%)case was unilateral mul tiple metastases.Most of the procedures of operation were local resection of the tumor ;however,only5cases underwent lobectomy.Results The postoperative complications included1case of severe bleeding cured by exploratory thoracotomy,2cases of lethal infections,and1case of atelectasis.Of 32cases,11sur -vived with out tumor at final follow-up.In25osteosarcoms,16were dead,2were lost from the follow-up;7cases of the other18cases that bilateral resections performed,were alive without tumor (38.9%)with a me di an survival time of 7years and3months.1each of Ewings sarcoma,paraosteal osteosarcoma and,chon-drosarco ma survived without tumor for 22years and5months,19years and3months,and13years and3months respectively.Conclusion Thoracotomy of pulmonary metastases of osteogenic sarcomas is an ef-fective method to salvage the patients life.The procedure of metastasectomy is local resection.The results al-so suggest that newadjurant chemotherapy is a important way to effect the condition of pulmonary metastases of osteogenic sarcomas.

Objective To describe the effect of cannualted rasps in reduc in g the fat embolic risks during preparation for femoral canal in experimental tot al hip arthroplasty. Methods Twelve mongrels were used to perform resection of b ilateral femoral heads, and randomly assigned to one of two groups with six each . In experiment group, impacting cannulated rasp was used in preparing femoral c anal; while, in control group, impacting traditional rasp was used. Both the ras ps were of same shape; however, there was a 4 mm diameter canal inside the cannu lated rasp connecting its two ends. A bone hole was made through the lateral fem oral cortex to the femoral canal at a point 12 cm distal to the greater trochant er in order to measure the intramedullary pressure of femoral canal when the fem oral canal was prepared with either rasp. The pathology of the postmortem pulmon ary tissue was analyzed. Using quantitative morphometry, the size of fat embolus in the lung tissues and the volume proportion of lung tissues occluded by fat w ere measured respectively. The statistical differences between the two groups we re analyzed using t test. Results In control group, the intramedullary pressure during preparation of femoral canal with traditional rasp increased with a peak of (34.5?10.2)kPa, pulmonary fat emboli were found in all mongrels, the volum e proportion of postmortem lung tissue occluded by fat was 0.64%, and pulmonary arterial pressure increased to (2.2?0.4)kPa[the normal value was (0.8?0.3 )kPa]; while in the experiment group, the intramedullary pressure peak increas ed to (22.4?7.7)kPa, significantly lower than that of the control group; the volume proportion of lung tissue occluded by fat was 0.21% which was also signif icantly lower than that of the control group, and pulmonary arterial pressure wa s (1.7?0.4)kPa. The differences between the two groups were significant in al l measured values. Conclusion The present study suggests that conventional prepa ration of canal can cause an increase of intramedullary pressure, which may lead to pulmonary fat embolism and cardiopulmonary impairment. However, the cannulat ed rasp can decrease the volume proportion of lung tissue occluded by fat and al leviate the influence of preparation of canal on cardiopulmonary function.

Objective: To study the super high-dose chemotherapy in drug-resistance Ⅲ B osteasarcoma with autologous bone marrow transplantation. Methods: The chemotherapy was carried out in 4 patients with drug-resistance Ⅲ B osteosarcoma. The autologous bone marrow was harvested before chemotherapy and reinfused after chemotherapy when the serum concentration of methotrexate reduced to 1.0?10~(-7) mol/L. The chemotherapy included ,methotrexate 500 mg/kg , adriamycin 25 - 75 mg/m~2 and vincristine 1.5 mg/m~2 with low dose citrovorum factor rescue. Results: Four patients tolerated the chemotherapy well and felt better than before. The pulmonary metastases had various degrees of reduction in 2 patient and calcified in 1 patient, but progressed in 1 patient. Conclusion: Super high-dose chemotherapy has good response in drug-resistance ⅢB osteosarcoma and is safe with autologous bone marrow transplantation. This regimen is worth to be further studied and be used in ⅡB osteosarcoma.

Objective To determine the applicability of locally continuo u s application of alendronate for the prevention of prosthesis aseptic loosening. Methods Using the method of in vitro cell culture to detect the influence of a lendronate with different concentrations(1?10－11mol/L,1?10－9mol/L,1?10－7mo l/L,1?10－6mol/L,1?10－5mol/L) on the proliferation, secretion and osteogenesi s of human osteoblasts as well as the effect of the motility, respiration, phago cytosis and bactericidal ability. Results Higher concentration of alendronate(1 ?10－6mol/L,1?10－5mol/L) improved local antiinfection ability, but inhibited osteogenesis (1?10－5mol/L). Lower concentration(1?10－11mol/L,1?10－9mol/L,1 ?10－7mol/L) inhibited the bactericidal effect of neutrophils, but stimulated o steogenesis(1?10－11mol/L,1?10－9mol/L). Conclusion Locally continuously usin g alendronate around prosthesis to prevent and treat aseptic loosening must be h andled with discretion. Its concentration should not be below 1?10－6mol/L in the early period after arthroplasty operation, but the concentration should be 1?10－11mol/L or 1?10－9mol/L in the late period.

Objective To investigate the effects of medullary reaming on respiratory and circulatory system in dog model during total hip replacement. Methods Twelve mongrels were randomly divided into two groups. In control group, femoral necks were cut while femoral canals were not disturbed. In experimental group, femoral canals were reamed with femoral rasps as done in total hip replacement. The changes of hemodynamics and pulmonary function were monitored during perioperative period. The postmortem pulmonary tissues were studied by pathological examination. Results No fat embolus was found in any lung sections of control group. Meanwhile, pulmonary fat emboli were found in all of experimental group. After fat embolism happened, cardiopulmonary effects included increased pulmonary artery pressure, pulmonary shunt and pulmonary vascular resistance accompanying a decrease in partial pressure of oxygen and cardiac output. There is statistically significant difference in response between the two groups. Conclusion The present study showed that embolic events and intraoperative pulmonary impairment are common during reaming of femoral medullary canal in total hip replacements. Further research can be made with this model in order to reduce the risk of fat embolism syndrome.

Objective To investigate the feasibility of abdominal aorta or common iliac artery occlusion by balloon catheter dilatation to decrease blood loss and promote operation safety during resection of sacral tumors and hip bone metastatic tumors. Methods From March 2003 to March 2005, 4 cases each of high level sacral tumors (3 of giant cell tumor and 1 of chordoma) and hip bone metastatic tumors (3 of lung cancer and 1 of osteosarcoma ) were resected after occlusion of the distal abdominal aorta or unilateral common iliac artery with balloon catheter dilatation in reducing intraoperative hemorrhage, the blocking time were 40 to 70 mins each with an interval of 15 to 20 mins. A balloon catheter was introduced through femoral artery at radiographic department one hour before the index operation. The balloon catheter was positioned proximal to the bifurcating of common iliac artery in lower abdominal aorta between superior mesenteric artery and renal artery confirmed by arteriography, or located in affected side common iliac artery. Results After the occlusion of abdominal aorta or unilateral common iliac artery, there was much less intraoperative hemorrhage (the amount of bleeding, 100 to 300 ml) and needed no hemostasis during the resection and curettage of the tumors. It possessed the similar effects as using the tourniquet in the operations of the extremities. The operating field was clean and the anatomic structures were exposed clearly. It was easy to define the boundary of the tumors and enable to perform complete tumor excisions and reduce contamination in the operative field. All the patients had smooth blood pressures during the operations. 1 case of sciatic nerve paralysis occurred in sacral giant cell tumor postoperation, but recovered 3 weeks later. Conclusion Occlusion of major blood supply arteries with balloon catheter dilatation can effectively reduce operative hemorrhage during the resection of sacral and hip tumors and it can promote the safety of the operations.

Objective To study the clinical features and treatment of multiple schwannomas (neurilemmomas). Methods 9 patients with multiple schwannomas treated with surgery from 1975 to 1999 were reviewed retrospectively. Results In 7 of the 9 cases of schwannomas, the number of tumor lesions was seen more than that diagnosed preoperatively. All the patients had surgical resection; 5 had enucleation and 4 had tumors excised with the invovled nerve. Recurrence occured in 4 patients. Conclusion Because of the difficulty in predetermination of the exact lesional number, thoroughly preoperative examination including MRI is nessesary. Enucleation is recommended to those tumors involving important nerves. There is a high rate of recurrence.

Object iv e To observe the intermediate-term results of the H /G total hip arthroplast y.Methods Thirty-fivecases(40hips)with the H /G THA were reviewed with an average of 7.5years fol-low-up(range,6to10.2years).In th is grou p,the primary lesions of hip included avascular necrosis of femoral head(1 2hips,10cases),congenital dysplasia of hip(9hips,8cases),femoral ne ck fracture(8hips,8cases),osteoarthritis(4hips,4cases),reversion(3 hips,3cases)and ankylosing spondylitis(4hips,2cas-es).The clinical res ults were scored with Harris methods.The roentgenographic results were analyzed with Am stutz meth ods.Results Theclinical average Harris scores were95in3-year follow-up,89in5-year fol-low-up,83in7.5-year follow-up. Roentgenographic results of femoral components showed20hips with in-tra medu llary ossification,18hips with cortical hypertrophy around the distal prosthe ses,25hips with lo cal re-di olucent line,10hips with osteolysis in femu r calar and2hips with implants subsiding less than7mm.Roentgenographic resul ts of acetabular component revealed20hips with radi olucent line(8compo n ents with around radiolu cent,12components with local radiolucent ),7hips with osteolysis and1hip with polyethylene lining defluxion.Conclusion Theresul ts of clinical and roentgenographic performance in mid-dle-term is not as go od as that in short-term.The abnormal bone reaction is evidently higher in mid dle-term than in short-term.Though the above-mentioned manifestation is only restricted on the roentgenogram with-out clinic symptom,however,further fol low-up is need ed.It should be noted that one case had revi sion be-cause of the polyethylene lining defluxion resulted from clip loosening on the metal ace tabular com po nent ;although this seldom happens both at home and abroad,more attention should be paid to the revi sion case re-sulted from the mechanical m alfunction not from the prosthesis loosening.

Objectives　To illustrate the functions of oblique films in observing the position of pedicle and fixing the screw through the study of preoperative and postoperative oblique films,and to determine a new,accurate and safe method of fixation.　Methods　In 30 cadavers, 8 had vertebral aortographies and 6 aortographies and myegraphies. According to preoperative films and anatomic marks, transpedicular screws were fixed (diameter 3.5 mm, length 24 mm, 160 stenless steel screws） for (C2)C3-C6(C7). The screw placement position and direction were compared in postoperative onlique film with CT,　and 　thus the result of 　X-ray oblique films was confirmed. Results　152 screws were in right placement and direction, which were confirmed by oblique films and CT. Five screws were estimated by oblique films as deflection outboard of the pedicle (3 by CT), and 3 screws as deflection inboard of the pedicle (2 by CT).　Conclusions　The position and direction of pedicle of the cervical spine cand be detecte by oblique films and may exactly estimate the transpedicular screw placement to see whether it enters the vertebra artery or spinal canal. The difference between oblique films and CT may be related to the scanning angle of CT and pseudomorph in CT.

Objectives　To illustrate the functions of oblique films in observing the position of pedicle and fixing the screw through the study of preoperative and postoperative oblique films,and to determine a new,accurate and safe method of fixation.　Methods　In 30 cadavers, 8 had vertebral aortographies and 6 aortographies and myegraphies. According to preoperative films and anatomic marks, transpedicular screws were fixed (diameter 3.5 mm, length 24 mm, 160 stenless steel screws） for (C2)C3-C6(C7). The screw placement position and direction were compared in postoperative onlique film with CT,　and 　thus the result of 　X-ray oblique films was confirmed. Results　152 screws were in right placement and direction, which were confirmed by oblique films and CT. Five screws were estimated by oblique films as deflection outboard of the pedicle (3 by CT), and 3 screws as deflection inboard of the pedicle (2 by CT).　Conclusions　The position and direction of pedicle of the cervical spine cand be detecte by oblique films and may exactly estimate the transpedicular screw placement to see whether it enters the vertebra artery or spinal canal. The difference between oblique films and CT may be related to the scanning angle of CT and pseudomorph in CT.