Semiotics of osteonecrosis and sequestration in femur has been studied on the basis of the data from roentgenography, linear tomography and computer tomography in 39 patients with transformation of acute hematogenous osteomyelitis into chronic one with the purpose of revealing the possible and most typical variants of proliferative changes in bone. It was established that during the process of assimilation the periosteal layers can convert into both compact bone and spongy bone. The average extent of periosteal layers in the shaft zone exceeded the size of destruction by 6.1±2.1 cm and the border of endosteal borders corresponded to that of periosteal layers. In metaphyseal zone the border of periosteal layers corresponded to the border of periosteal cambial layer and was not visualized by destruction spreading: the border of destruction could be located both proximally and distally to the periosteal layers' border.