Bone cutting apparatus and method

A prosthetic implant and an apparatus for preparing a bone for receiving the prosthetic implant which prosthetic implant includes a body portion having a predetermined size and a stem portion coupled to the body portion, and with the body portion having a plurality of fins extending outwardly therefrom and with the stem portion having a selected one of at least two different stem sizes, the apparatus comprising:

• a cutter for cutting the bone including means for cutting fin tracks into the bone to prepare the bone for receiving the body portion of the implant;
• at least two rods having different sizes corresponding to the at least two different stem sizes;
• means for coupling a selected rod to the cutter, the selected rod having a size corresponding to the selected size of the stem, the rod being removable from the cutter to permit a rod having a different size to be selectively coupled to the cutter depending upon the selected size of the stem of the implant;
• and
• means coupled to the cutter for driving the cutter and the selected rod into the bone.

An apparatus for preparing a surface of a bone for receiving an implant having a body portion with a predetermined shape including fin portions extending outwardly thereof and a stem portion, the apparatus comprising:

• a cutter for cutting the surface of the bone in a pattern corresponding to the predetermined shape of the body portion as well as cutting fin tracks for receiving the implant;
• a rod coupled to the cutter for locating the cutter relative to the bone;
• a collar with an opening therethrough slidably coupled to the cutter in a predetermined orientation, the collar being configured to engage the bone to determine a proper rotational position of the cutter relative to the bone about a longitudinal axis of the rod;
• and
• means coupled to the cutter for driving the cutter and rod into the bone.

An apparatus for preparing a surface of a bone for receiving an implant having a body portion with a predetermined shape and a stem portion, the apparatus comprising:

• a cutter for cutting the surface of the bone in a pattern corresponding to the predetermined shape of the body portion of the implant;
• a rod coupled to the cutter for locating the cutter relative to the bone;
• a collar slidably coupled to the cutter in a predetermined orientation, the collar being configured to engage the bone to determine a proper rotational position of the cutter relative to the bone about a longitudinal axis of the rod;
• means coupled to the cutter for driving the cutter and rod into the bone;
• wherein the body portion of the implant includes a plurality of fins arranged in a predetermined pattern on the body portion, and the cutter includes a plurality of fins arranged in the same pattern as the plurality of fins on the body portion of the implant so that the cutter cuts the bone in a shape corresponding to the shape of the body portion of the implant;
• and
• wherein the collar is formed to include a plurality of slots for receiving the plurality of fins of the cutter therethrough to align the collar in the predetermine orientation relative to the cutter.

A method of preparing a bone for receiving a prosthetic implant which includes a body potion having a predetermined size and a stem portion coupled to the body portion, the body portion having a plurality of fins extending outwardly therefrom and the stem portion having a selected one of at least two different stem sizes, the method comprising the steps of:

• reaming an intramedullary canal of the bone with a reamer to determine the selected size of the stem;
• selecting a cutter and a rod having sizes corresponding to the sizes of the body portion with its fins and the stem of the prosthetic implant, respectively, from a set of cutters and rods having various sizes;
• coupling the selected cutter and the selected rod together to form a cutting apparatus;
• driving the cutting apparatus into the bone so that the rod enters the reamed intramedullary canal of the bone and the cutter cuts the bone in a pattern to establish the position of the body and fins relative to the bone;
• and
• installing the implant into the bone using the cut pattern as a guide.

A method of preparing a bone for receiving a prosthetic implant which includes a body portion having a predetermined size and a stem portion coupled to the body portion, the stem portion having a selected one of at least two different stem sizes the method comprising the steps of:

• reaming an intramedullary canal of the bone with a reamer to determine the selected size of the stem;
• selecting a cutter and a rod having sizes corresponding to the sizes of the body portion and stem of the prosthetic implant, respectively, from a set of cutters and rods having various sizes;
• coupling the selected cutter and the selected rod together to form a cutting apparatus;
• driving the cutting apparatus into the bone so that the rod enters the reamed intramedullary canal of the bone and the cutter cuts the bone in a pattern to establish the position of the implant relative to the bone;
• installing the implant into the bone using the cut pattern as a guide;
• further comprising the step of rotationally aligning the cutting apparatus relative to the bone prior to the driving step;
• and
• wherein the aligning step includes the step of placing a collar on the cutter in a predetermined orientation and rotating the cutting apparatus about a longitudinal axis of the rod until the collar is substantially parallel to a resected surface of the bone.