Apparatus for producing relief grooves in pan-shaped bones

Claim 1

Apparatus for producing relief grooves in a pan-shaped bone such as the acetabulum of a human hip joint, comprising: an elongated drive shaft having a free end; a casing arranged at the free end of said drive shaft, said casing having an outside contour of generally hemispherical shape facing away from said drive shaft and which shape is at most coextensive with the pan contour of the bone; cutting means arranged in said casing for movement transversely of the longitudinal axis of said drive shaft, said cutting means having a cutting edge which is movable between a first position inside said casing and a second position outside said casing in a radial direction relative to the longitudinal axis of said drive shaft, said casing having passageways to allow said cutting edge to emerge from said casing toward the second position; and an adjusting bush threadably connected to and arranged concentrically on said drive shaft for radially moving said cutting means, said adjusting bush including a first section having an increasing outer diameter and a second, successively connected section have a decreasing outer diameter in the direction of the longitudinal axis of said drive shaft, the outer circumferential surfaces of said first and said second sections operatively engaging said cutting means.