22 women and 2 men with a mean age of 75 (51-90) years underwent replacement of the proximal femur for failed total hip arthroplasty by a modular femoral resection endoprosthesis (KMFTR). The indications were bone loss in aseptic loosening (n 8), fracture (n 12) and Girdlestone hips (n 4). After a mean follow-up of 5 (2-10) years, the Harris Hip Score improved from an average of 17 (4-43) to 79 (50-97). In 19 patients, the proximal femur was kept as an autograft and was wrapped around the resection parts of the modular prosthesis as a cortical sleeve. Bone formation in these 19 hips took place in 18 at the dorsal, in 17 at the medial, in 8 at the lateral and in 7 at the ventral aspect of the femur. The bone bridge formed within the first year and persisted in amount and distribution during the time of observation. In the 5 patients without a remaining cortical sleeve around the resection parts of the prosthesis, no bone bridge was formed. These 5 patients showed stress-shielding at the prosthesis-bone-junction. Until now, none of the 24 patients has undergone additional surgery.