Apparatus for the working of a bone which is to be provided with a shell prosthesis

Claim 1

Apparatus for the working of a bone, especially the femur head of a human hip joint, which bone is to be provided with a shell-shaped endoprosthesis, comprising: a drivable drive shaft having a free end; a pot-shaped cutting head arranged on the free end of said drive shaft, said cutting head has an inner end face which faces away from said drive shaft free end and surrounds the axis of said drive shaft, and a circular free edge on said cutting head which edge is concentric with the axis of said drive shaft; first cutting means arranged at the inner end face of said cutting head for defining an arcuately shaped surface on the bone which surface corresponds to the inner surface of the shell-shaped endoprosthesis which is to be applied to the bone; second cutting means including uniformly spaced cutting teeth arranged at said free edge of said cutting head for defining a cylindrical jacket on the bone; third cutting means extending from said inner end face of said cutting head away from said drive shaft for providing a cylindrical bore in the bone concentric with the axis of said drive shaft, said third cutting means having a central guiding bore extending in the axial direction of said drive shaft; and a guiding pin for cooperating with said guiding bore to guide said cutting head through the bone, said guiding pin to be arranged in a bone section treated such that said pin protrudes from the bone and is alignable with said guide bore.