Rotationplasty was used in two cases of failed limb salvage in adults after tumor resection and reconstruction. Each patient had distal femoral osteosarcoma, one treated with osteoarticular allograft reconstruction, the other with a custom endoprosthetic reconstruction. Both patients had failure attributable to infection, and after multiple surgeries, elected to have rotationplasty. Both had complications associated with the rotationplasty but went on to have functional limbs with Musculoskeletal Tumor Society functional scores of 67% and 87%. One patient died of metastatic disease 29 months after rotationplasty, the other had no problems 50 months after rotationplasty. Although rotationplasty offers a functional improvement over transfemoral amputation in the salvage of failed tumor reconstructions, only 10 such cases have been reported in adults. Rotationplasty should be considered in selected patients for whom an amputation is being considered after failed limb salvage surgery.