The classic book of Professor Gerhard Küncher, a German surgeon who, back in the 40s of the XX century, substantiated the biomechanical principles of intramedullary osteosynthesis and developed techniques for operations on all segments of the limbs, which continue to be improved and applied to this day. Kuncher's contribution to the development of traumatological and orthopedic science cannot be overestimated; he can rightfully be called the founding father of intramedullary osteosynthesis. The book was co-written with Richard Matz.