Massive bone defects often are caused by radical resection of bone tumors. Reconstruction of the defect by reimplantation of the resected bone segment after it has been devitalized is advantageous because of its ability to match the size of the defect. In addition, this technique carries a low risk for local recurrence of the tumor, avoids immunologic reaction, and is low in cost. However, limited osteogenic potential of the devitalized bone often leads to delayed union, gradual resorption, and mechanical weakness of the reimplanted segment. We applied rhBMP-2 in a biodegradable polymer delivery system to the devitalized bone. Middiaphyseal bone defects were created by resection in rat femurs. The resected segments were autoclaved at 135 degrees C for 15 minutes, coated with a rhBMP-2-retaining paste on the outer surface, and then reimplanted into the defects. In a brief time, newly formed bone was seen on the surface of the devitalized bone. After 12 weeks, a solid bone mass encasing the dead bone segments was consistently formed and abundant new bone formation was visible in the segments as they were remodeled. The amount of new bone formed could be regulated by the amount of the rhBMP-2-retaining paste applied to the bone segments. This method presents a new approach for the reconstruction of bone defects.