Femoral prosthesis with insertion/extraction feature

1. A femoral prosthesis system, comprising:

a femoral prosthesis including

a femoral stem with a proximal end portion defining a proximal stem axis,

a neck portion located proximally of the proximal end portion, and

an insertion/extraction cavity extending distally from a proximal surface of the neck portion, the cavity defining an insertion/extraction cavity axis which, when projected onto a coronal plane including the proximal stem axis, is not parallel with the proximal stem axis; and

an insertion/extraction instrument including

a distal end portion configured to couple with the insertion/extraction cavity, and

a shaft defining an impact axis and configured such that the impact axis is parallel with the insertion/extraction cavity axis when the insertion/extraction instrument is coupled with the femoral prosthesis, wherein the impact axis is aligned with the insertion/extraction cavity axis when the insertion/extraction instrument is coupled with the femoral prosthesis.

2. The system of claim 1 , wherein when the insertion/extraction cavity axis is projected onto the coronal plane the insertion/extraction cavity axis extends proximally and medially from the proximal stem axis.

3. The system of claim 2 , wherein when the insertion/extraction cavity axis is projected onto the coronal plane the insertion/extraction cavity axis extends proximally and medially from the proximal stem axis at an angle in the range of approximately one degree through approximately forty-five degrees.

4. The system of claim 2 , wherein when the insertion/extraction cavity axis is projected onto the coronal plane the insertion/extraction cavity axis extends proximally and medially from the proximal stem axis at an angle of about twelve degrees.

5. The system of claim 2 , wherein the femoral stem is substantially straight.

6. The system of claim 1 , wherein:

the insertion/extraction cavity includes a first keyed portion;

the insertion/extraction instrument includes a second keyed portion; and

the first and second keyed portions are configured to mate with each other in a keyed relationship.

7. The system of claim 6 , wherein the first keyed portion includes a first keyed portion surface arranged substantially orthogonally relative to the insertion/extraction cavity axis.

8. The system of claim 6 , wherein the insertion/extraction cavity further includes a threaded portion configured to receive a threaded portion of the insertion/extraction instrument.

9. The system of claim 8 , wherein the threaded portion of the insertion/extraction instrument is rotatable with respect to the second keyed portion.

10. A method of inserting a femoral prosthesis comprising:

coupling an insertion/extraction instrument with an insertion/extraction cavity that is located at a proximal portion of a femoral component and defines an insertion/extraction cavity axis, said coupling being performed such that an impact axis defined by a shaft of the insertion/extraction instrument is aligned with the insertion/extraction cavity axis and not parallel with a longitudinal axis defined by a proximal stem portion of the femoral prosthesis;

inserting a distal end portion of the femoral prosthesis into a femur; and

impacting a proximal end portion of the insertion/extraction instrument.

11. The method of claim 10 , wherein coupling the insertion/extraction instrument with the insertion/extraction cavity comprises:

threadedly engaging a threaded portion of the insertion/extraction cavity with a threaded portion of the insertion/extraction instrument.

12. The method of claim 11 , wherein threadedly engaging the threaded portion of the insertion/extraction cavity with the threaded portion of the insertion/extraction instrument comprises:

rotating the proximal end portion of the insertion/extraction instrument with respect to a housing of the insertion/extraction instrument.

13. The method of claim 12 , wherein coupling the insertion/extraction instrument with the insertion/extraction cavity comprises:

inserting a keyed portion of the insertion/extraction instrument into a keyed portion of the insertion/extraction cavity.

14. The method of claim 13 , wherein threadedly engaging the threaded portion of the insertion/extraction cavity with the threaded portion of the insertion/extraction instrument occurs prior to inserting the keyed portion of the insertion/extraction instrument into the keyed portion of the insertion/extraction cavity.