Abstract: In a long bone endoprosthesis, the anchoring shaft on at least a part of its length has a cross section of generally rectangular or other polygonal shape and with rounded corners and straight side sections allowing the anchoring shaft to fit more closely with the bone when the anchoring shaft is inserted into a bone recess cut with a rotary cutting head having a minimum radius, the rounded corners of the anchoring shaft having radii equal to or greater than the minimum radius of the cutter head.

Abstract: A plate arrangement for the osteosynthesis of fractured tubular bones is made of two plate sections each connectable to associated bone sections or fragments by fastening screws passing through the plate parts. The plate parts are slidable relative to one another by means of a telescope arrangement connecting the two parts, and holes formed in the two parts for attaching the parts to bone sections or fragments are elongated in the direction perpendicular to the telescope axis to allow fastening screws to be inserted at different angles allowing the surgeon some choice in selecting a most favorable position at which to insert each screw into the associated bone fragment.