Patent ID: 8454609

Claim:
An acetabular reamer for reaming an acetabulum, reaction forces being exerted onto said acetabular reamer by said acetabulum when said acetabulum is reamed, said acetabular reamer comprising: a body, said body defining a rotation axis about which said acetabular reamer is rotatable; a reaming element operatively coupled to said body so as to be movable between a reaming element inner position and a reaming element outer position relatively thereto, said reaming element being positioned further away from said rotation axis in said reaming element outer position than in said reaming element inner position; an actuator operatively coupled to said reaming elements for moving said reaming elements between said reaming element inner and outer positions; and a reaming element lock configurable between a locked configuration and an unlocked configuration, said reaming element lock being operatively coupled to said reaming element in a manner such that when said reaming element lock is in said unlocked configuration, said reaming element is freely movable by said actuator between said reaming element inner and outer positions, and when said reaming element lock is in said locked configuration, said reaming element lock prevents said reaming element from moving relatively to said body; said reaming element lock being configured, sized and operatively coupled to said reaming element and said body in a manner such that when said reaming element lock is in said locked configuration and said reaction forces are exerted onto said reaming element, a larger portion of said reaction forces is transmitted to said body than to said actuator; said actuator including a reaming element mounting portion for mounting said reaming element thereto, said reaming element mounting portion including a radially central portion and an arm extending outwardly from said radially central portion, said reaming element being mounted to said arm, said actuator also including a mounting portion support for supporting said reaming element mounting portion, said reaming element support being mounted to said body so as to be longitudinally movable therealong; said arm and said reaming element being configured and sized such that said reaming element is moved between said reaming element inner and outer portions when said mounting portion support is moved longitudinally along said body, said mounting portion support being longitudinally movable along said body with said arm keeping a constant circumferential orientation relatively to said body, said mounting portion support defining a threaded section extending longitudinally therealong, said actuator including a nut threaded onto said threaded section so as to be rotatable thereabout, said nut being operatively coupled to said body so as to be longitudinally fixed relatively to said body, whereby rotating said nut relatively to said body moves said mounting portion support longitudinally along said body.