[Designing special prosthesis "spacer"]

Malignant diseases of the medial part of the femur, humerus and tibia, treated with surgical removal of the affected part of the bone and prosthesis fitting special "Spacer". This type of prosthesis is made in the form of the proximal and distal components that connect by screws. The design of endoprosthesis provides without possible rotation linear relationship and allows the transfer of load from the proximal to the distal bone, but the screws that provide connection are not exposed to stress. For pro-per sizing and implementation of a special prosthesis is necessary to determine the geometric parameters of bone mass and disease and then develop a computer model of the prosthesis. Designing a special prosthesis "spacer" is a complex procedure based on the processing of diagnostic images (X-ray, CT or MRI) with the use of specialized software digitized picture elements pixels translate into voxels. In this way a geometric model contains a form of external (KORTEX), and the internal geometry of the bone (medullary canal). On the basis of such a developed computer models is possible accurately determine the part of the bone that is necessary to remove, and the size of medullary canal space that is built into proximal or distal component of special endoprosthesis "Spacer".