Limb salvage surgery for primary bone sarcoma of the lower extremities: long-term consequences of endoprosthetic reconstructions.

Abstract

Adjuvant chemotherapy and endoprosthetic replacement for bone sarcomas of the lower extremity is well established. The specific long-term consequences of these endoprosthetic reconstructions for the patient's affected limb are unknown. The oncologic results and the survival of the endoprostheses were reviewed in 32 patients with primary bone sarcoma of the femur or proximal tibia. There were 26 high-grade sarcomas, and 6 low-grade sarcomas. A proximal femoral endoprosthesis was used for reconstruction in 4 patients, a total or push-through femoral endoprosthesis in 11 patients, a distal femoral endoprosthesis in 15 patients, and a proximal tibial endoprosthesis in two patients. Median survival was 10 years (range, 1.1 to 18.9 years) for patients with high-grade sarcoma, and 8.1 years (range, 7.1 to 10 years) for patients with low-grade sarcomas. Distant metastases developed in seven patients (22%), all with stage IIB sarcoma, with concomitant local recurrence in 3 patients (9%). Five-year overall and disease-free survival rates for high-grade sarcomas were 81% and 73%, respectively. The overall endoprosthetic survival rate was 87% at 5 years, 80% at 10 years, and 56% at 15 years. Median follow-up of the original endoprostheses was 8.3 years (range, 0.6 to 18.7 years). Endoprosthesis-related complications occurred in 13 patients (41%); most complications were mechanical failures. The highest complication rate was found in distal femoral replacements (60%); amputation was necessary in both patients treated with a proximal tibial endoprosthesis. Five endoprostheses (16%) were revised. An amputation of the involved limb was performed in four patients (13%): in two patients because of local recurrence and in the other two patients because of infection. For patients alive at follow-up, the median functional Enneking evaluation score was 22 points (range, 12 to 28 points), with the highest functional scores in patients with a distal femoral endoprosthesis, and the lowest functional scores in patients with total or push-through femoral replacements. Endoprosthetic reconstructions gave satisfying functional results in most patients after long-term survival. However, the proximal tibial and distal femoral endoprosthesis are particularly at risk for long-term endoprosthetic complications requiring additional surgical procedures.