After resection of a bone tumor, reconstruction can be performed with use of a variety of techniques, including large-segment allografts, allograft-prosthetic composites, endoprostheses, and other types of tissue-transfer procedures1-5. All of these options rely on healthy native bone and soft tissues. The difficulty of achieving a successful outcome increases as the segment of remaining normal bone decreases6,7. For example, endoprosthetic implants with stems require a sufficient length of bone to achieve either press-fit or cemented fixation. Similarly, allografts and vascularized bone transfers require healthy bone to achieve adequate fixation8. When short segments of bone remain after tumor resection, traditional implants will not fit, and the surgeon has to rely on alternatives such as allograft-prosthetic composites, custom implants, or replacement of the entire bone (as with total replacement of the femur). Determining what constitutes sufficient bone to perform a reconstruction is not known and depends on the surgeon’s experience, the implants that are available, the patient’s acceptance of surgical risks, and the resources available for postoperative rehabilitation. To the best of our knowledge, there are no studies in the literature that specifically provide information or guidance on how to perform an endoprosthetic reconstruction of the femur when only the proximal metaphysis is intact. We present a case of a seventy-five-year-old man who underwent successful endoprosthetic replacement of the entire femur, distal to the lesser trochanter and including the knee joint, after complications associated with a chondrosarcoma resection. This case demonstrates a novel technique with use of a compression osseointegration implant for preservation of the native hip joint while replacing almost the entire femur. The patient was informed that data concerning the case would be submitted for publication, and he provided consent. A seventy-five-year-old man presented with a four-to-six-month history of pain …