Abstract: An apparatus and method for making one or more grooves in the medullary canal surface of a bone to secure and reduce the risk of rotational failure of implanted orthopedic endoprostheses. The apparatus includes a head and, attached thereto, a body adapted for insertion into the medullary canal of a bone. The apparatus also includes a channel therethrough that is enclosed in the head and open in the body. One or more grooves is made in the medullary canal surface of a bone by placing the body of the apparatus in the medullary canal, inserting a cutting device in the channel, and then using the cutting device to remove an amount of bone tissue sufficient to form a groove or grooves. The risk of rotational failure of implanted orthopedic endoprostheses is reduced by implanting prostheses that engage and are secured in place by the groove or grooves.