Modular hip prosthesis

1. A modular hip prosthesis, comprising:

an elongated stem extending from a proximal region to a distal region;

a proximal body having a bore with a threaded section and being removably connectable to the stem;

a neck connectable to the proximal region of the stem;

a separate, discrete, expansible collet lockingly positioned between the stem and proximal body, such that the expansible collet is seated radially within the proximal body; and

a locking member having external threads that threadably engage the threaded section of the proximal body to lock the proximal body and collet together and to the stem, wherein the looking member is seated axially adjacent the expansible collet,

wherein the neck is movable with respect to the proximal body, until being locked into position by the locking member.

2. The modular hip prosthesis of claim 1 wherein the locking member is a cylindrical nut with external threads.

3. The modular prosthesis of claim 2 wherein the collet forms a taper fit with the proximal body below the threaded section.

4. The modular hip prosthesis of claim 1 wherein the neck is rotationally adjustable about the stem.

5. The modular hip prosthesis of claim 4 wherein the neck is removably connectable to the stem.

6. The modular prosthesis of claim 5 wherein the proximal body is axially adjustable about the stem.

7. The modular prosthesis of claim 6 wherein the proximal body is rotationally adjustable about the stem.

8. A modular hip prosthesis, comprising:

a femoral stem extending from a proximal region to a distal region;

a neck being rotationally adjustable about the stem;

a proximal body being both rotationally and axially adjustable about the stem, the proximal body being positioned around the stem;

a separate, discrete, expansible collet lockingly engaged between the stem and the proximal body, such that the expansible collet is seated radially within the proximal body; and

a locking member that engages the proximal body and locks the proximal body to the stem,

wherein the neck is movable with respect to the proximal body, until being locked into the position by the locking member; and

further wherein the proximal body includes a threaded section located along an internal longitudinal bore, and the locking member threadably engages the threaded section of the proximal body.

9. The modular hip prosthesis of claim 8 wherein the locking member is positionable over the stem and includes external threads that threadably engage the threaded section of the proximal body.

10. The modular hip prosthesis of claim 9 wherein the locking member has a ring shape.

11. The modular hip prosthesis of claim 8 wherein the proximal body and Neck are removably connectable to the stem.

12. The modular hip prosthesis of claim 8 wherein the neck locks to the proximal region of the stem.

13. The modular hip prosthesis of claim 12 wherein the proximal body locks to the sleeve.

14. The modular hip prosthesis of claim 8 wherein the locking member is an annular member.

15. The modular hip prosthesis of claim 8 wherein the locking member is seated axially adjacent the flexible sleeve.

16. A modular hip prosthesis, comprising:

a stem extending from a proximal end to a distal end;

a neck being rotationally adjustable about the stem and removably connected to the proximal end of the stem, said neck including a bore that receives the proximal end of the stem;

a proximal body being both rotationally and axially adjustable about the stem, the proximal body being positioned around the stem;

a sleeve separate, discrete, expansible collet lockingly positioned radically between the the stem and the proximal body, wherein the sleeve is radically flexible and includes a purality of longitudinal slots; and

a locking member that engages the proximal body to lock the proximal body and sleeve to the stem,

wherein the neck is movable with respect to the proximal body, until being locked into position by the locking member; and

further wherein the proximal body includes a threaded section located along on internal longitudinal bore, and locking member threadably engages the threaded section of the proximal body.

17. The modular hip prosthesis of claim 16 wherein the proximal body, sleeve, and locking member are separate components.

18. The modular hip prosthesis of claim 17 wherein the proximal body, sleeve, and locking member are removably connectable to the stem.

19. The modular hip prosthesis of claim 16 wherein the locking member is an annular member configured to surround the proximal end of the stem.

20. The modular hip prosthesis of claim 16 wherein the bore in the neck is tapered and is configured to engage a tapered surface on the proximal end of the stem.