Seven patients underwent total resection of the femur with replacement by the Kotz modular femur and tibia reconstruction system (KMFTR); three of these operations were for primary malignant tumours and four were salvage procedures after failed limb-sparing surgery. Clinical and radiological results were excellent or good at final follow up at an average of 23 months. A new method of radiological assessment has been used for the acetabular component of bipolar hip endoprosthesis. The polyethylene bush of the hinged knee component may wear. Reattachment of the abductors to the endoprostheses often fails and we now suture the abductors to the fascia lata. The rectus femoris muscle should be saved, if possible, after resection. When total excision of the quadriceps is indicated, the knee should be arthrodesed. The KMFTR is easy to use and has provided good medium to long term results in our cases.