COMPLICATIONS AND RESULTS OF HIGH-GRADE O STEOSARCOMA OF THE LOWER-LIMB - A STUDY OF 20 CASES

Over 11 years we treated 30 osteosarcomas : 20 of them were high grade non metastatic osteosarcomas of the lower limb, which were treated by neoadjuvant chemotherapy (Rosen T10, or OS 87 protocol of the French Society for Pediatric Oncology). Material and methods There were 12 ma les and 8 females; the mean age was 19 years (range 12-51). The site o f the tumor was the femoral neck (1 case), femoral diaphysis (2 cases) , distal femur (12 cases), proximal tibia (4 cases), distal tibia (1 c ase), 3 were IIA and 17 IIB according to Enneking system. Conservative treatment was performed in 17 cases : there were 12 knee prostheses, 4 allografts and 1 knee arthrodesis with allograft. Results a) Surgica l complications : Mechanical complications occurred in 10 patients. Th e function was preserved 8 times. In 2 patients the knee became stiff. An infection occurred in 3 patients a conservative treatment was poss ible in 2 of them with a fair result. In the third case, an above-the- knee amputation had to be done. b) Functional results were studied acc ording to Enneking rating. 14 arthroplasties (12 done as first surgica l treatment and 2 after mechanical complication) had a 68, 19 score. c ) Oncologic results 8 patients were good respondents and 12 patients w ere bad respondents to chemotherapy according to Huvos grading. One lo cal relapse was observed which could be treated by mean of a second ch emotherapy and a prosthetic reconstruction. The patient is still alive and disease-free at 7 years (9 years after the diagnosis of the osteo sarcoma). 5 patients had distant metastasis (lung, bones, and brain). One out of 5 was good respondent and 4 out of 5 are presently dead. Us ing Kaplan Meier statistical analysis, the overall survival wzs 76.8 p er cent and the event-free survival was 67,4 per cent at 80 months. Co nclusion We preferred a simple prosthetic reconstruction without osseo us sleeve or an intercalary allograft if possible : these procedures a llow the patient very rapid autonomy to have despite a prolonged chemo therapy.