Injuries of unstable pertrochanteric fractures of the upper femur represent a contingent with high multi-morbidity at highest average age. The only successful procedures within biologically set boundaries, would be those of an early and weight-bearing resistive osteo-synthesis. Starting in 1979 till the middle of 1982, we treated 70 unstable pertrochanteric fractures out of 350 proximal femur fractures, with this compression hip screw. Because of its underlying bio-mechanical principle, its advantageous operative handling, as well as high durability of the material used, this version of an osteosynthesis showed few complications. We found neither head penetration and pseudoarthrosis, nor did we find any implant bending and breaking so far. Although averaging almost 80 years, 63% of our patients could be released after hospitalization for an average of 39 days, leaving at full mobility. The set goal of an early weight-bearing with elderly patients was fully achieved by means of this version of osteo-synthesis, since dynamic compression of even comminuted fracture zones permitted a statically sound and unhindered possibility at weight-bearing.