Ninety-three consecutive prosthetic reconstructions performed for limb salvage after the resection of sarcomas of the lower extremity were reviewed to determine how long the reconstructions lasted, how successful they were in avoiding amputation in the long term, how significant a problem was aseptic loosening, and what was the associated patient survival. Reconstruction was of the proximal femur in 16, distal femur in 61 and proximal tibia in 16 patients. Minimum follow-up time was 24 months, with a median of 66 months and mean of 80 months. If any event leading to the removal of the prosthesis is considered a reason for failure, the event-free prosthetic survival at five years for the proximal femur was 88%, distal femur 59%, and proximal tibia 54%. Limb survival at five years was significantly better, with the proximal femur at 88%, distal femur at 88%, and proximal tibia at 78% intact. Aseptic loosening survival was better than the event free prosthetic survival, which demonstrates the influence of factors such as sepsis (hematogenous) or wound necrosis that lead to prosthetic removal. Aseptic loosening survivorship of the proximal femur at five years was 100%; distal femur, 78%; and the proximal tibia, 73%. At five years, patient survival was low for the proximal femur (62%) and distal femur (75%) but notably better for the proximal tibia (93%). Prosthetic, extremity, and patient survival differed depending on the site. Wound necrosis was a significant cause of prosthetic removal and loss of limb early in this series, but the more aggressive use of soft tissue procedures has improved this.(ABSTRACT TRUNCATED AT 250 WORDS)