The use of megaprostheses for knee reconstruction after distal femur resection in young bone sarcoma patients has become popular since early ′80. The authors reviewed their experience with different distal femur megaprostheses in children. Clinico-radiographic evolution in a consecutive series of 113 children, that had implanted below age 15 (range 6-14) a distal femur megaprosthesis in the period 1984-2007, was analized. A modular implant was used in 97 cases with uncemented femoral stem (three different models along the period). The implant presented fixed-hinge joint in 78 cases while rotating-hinge knee was utilized in 19 cases. In 39 cases the fixed-hinge joint had a tibial component with a polished stem to allow the residual growth of proximal tibia; in two cases a mechanically extendable prosthesis was used. A custom-made noninvasive extendable prosthesis with cemented femoral stem and smooth uncemented tibial stem was used in 15 cases since 2002. Radiological and functional results were analysed and a statistical comparison of implant outcome according different stems was obtained.Aim
Method
Prognostic stratification of patients with non-metastatic osteosarcoma may improve the clinical management and the design of clinical trials. Data from 773 patients [median age 15 years (3-40)] treated at our Institute from 1983 to 2000 with high-dose methotrexate, cisplatin, doxorubicin and ifosfamide (neoadjuvant chemotherapy) were analyzed. After multivariate analysis including age, site, tumour volume (cut-off 200 mL), serum LDH and Alkaline Phosphatase (SAP), histology (osteoblastic and chondroblastic vs others), high LDH and SAP, osteoblastic and chondroblastic histotypes resulted independent prognostic factors of DFS. Patients were grouped according to a score from 0 (absence) to 3 (one to 3 adverse factors). The scoring system was implemented by the addition of PgP expression and grade of chemotherapy-induced necrosis. A score of 0, 1, 2, 3 was given to 14%, 38%, 32% and 16% of patients respectively.10-year DFS was 80% (95%CI 72-89) for score of 0, 58% (95%CI 52-64) for 1, 53% (95%CI 46-59) for 2 and 40% (95%CI 32-50) for 3 (p= 0.001). PgP expression (168 patients) identified patients with 100% probability of DFS (score of 0 and negative PgP) and patients with 18% (95%CI 52-64) DFS (score of 3 and positive PgP). Good (GR) and poor responder (PR) patients had the same probability of DFS in case of score of 0 [GR82% (95% CI 72-91), PR79% (95% CI 65-93)] and score of 3 [GR43% (95% CI 32-55) PR36% (95% CI 21-51)]. Different probability of DFS in case of score of 1 [GR64% (95% CI 57-72) PR47% (95% CI 36-59)] and score of 2 [GR63% (95% CI 55-71) PR36% (95% CI 21-51)]. It is possible to stratify outcomes of patients with non metastatic osteosarcoma of the extremity by means of a simple score based on easily available clinical parameters. This scoring system is worth to be validated on larger series.
