Estimation of defect volume in segmental defects of the tibia and femur

Background: With the advent of modern limb salvage techniques, segmental bo ne loss in the lower extremity has become more common. Methods: To aid preoperative planning when dealing with segmental bone loss in the femur and tibia, we performed a cadaveric study to estimate the vol ume of autogenous or allograft material required to fill defects located in various areas of the bones. Results: The greatest volume was generally required in metaphyseal defects, with an average of 12 cc/cm in the distal femur and proximal tibia, 11 cc/ cm in the proximal femur, and 6 cc/cm in the distal tibia, Diaphyseal defec ts were found to have the least variability with regard to the volume of gr aft material required for different specimens. Femoral diaphyseal defects r equired 7 cc/cm and tibial diaphyseal defects required 5 cc/cm, A slightly larger volume of allograft material was needed to fill all defects compared with autograft, Conclusion: This method allows one to estimate the amount of graft required for a defect of the femur and the tibia.