Prosthetic Survival and Functional Evaluation in Prosthetic Reconstruction of Malignant Bone Tumors of the Proximal Tibia

Abstract

Purpose: This study retrospectively analyzed the prosthetic survival and functional results after a prosthetic reconstruction for malignant bone tumors of the proximal tibia. Materials and Methods: Thirty-five patients (32 osteosarcomas and 3 chondrosarcomas) were followedup for an average 72 months (24-167 months). A gastrocnemius flap was transferred in 12 patients and cement fixation of the stem was performed in 10. More than 40% of the bone length was resected in 12 patients. Results: Three patients had died of the disease at the time of the final follow-up. There were one local recurrence and five distant metastases. The major complications were infection (5), aseptic loosening (5) and periprosthetic fractures (1). Gastrocnemius flap affected the incidence of a deep infection in the proximal tibia (17.4% vs. 8.3%) but there were no statistical correlation. A resection of >40% of the involved tibia increased the incidence of aseptic loosening (p=0.002). The rate of prosthetic survival was 72% at 5 years and 58% at 10 years. The functional score at the final follow-up was 81% (43-93%). Conclusion: A prosthetic reconstruction in the proximal tibia showed acceptable oncologic and functional outcomes in patients at an intermediate term follow-up. Infection and loosening were the main factors threatening the survival of the prosthesis.