Method and apparatus for performing minimally invasive arthroscopic procedures

1. A surgical instrument, said surgical instrument comprising:

a hollow shaft having a distal end and a proximal end;

a handle disposed at said proximal end of said hollow shaft;

a flexible distal end segment disposed at said distal end of said hollow shaft, said flexible distal end segment comprising a distal end and a proximal end, with said proximal end of said flexible distal end segment being mounted to said distal end of said hollow shaft;

at least one tensioning member extending between said distal end of said flexible distal end segment and said handle for manipulating said distal end of said flexible distal end segment relative to said hollow shaft whereby to provide curvilinear bending of said flexible distal end segment relative to said hollow shaft;

an outer cutting window member rotatably mounted to said distal end of said flexible distal end segment;

an inner extension tube extending through said hollow shaft and said flexible distal end segment for selectively rotating said outer cutting window member relative to said flexible distal end segment, said inner extension tube having a distal end and a proximal end, said distal end of said inner extension tube being mounted to said outer cutting window member and said proximal end of said inner extension tube extending to said handle;

an inner cutting member rotatably disposed within said outer cutting window member; and

a rotational element for rotating said inner cutting member relative to said outer cutting window member, said rotational element comprising a distal end connected to said inner cutting member and a proximal end extending to said handle;

wherein:

said surgical instrument provides at least the following independent degrees of freedom: curvilinear bending of said flexible distal end segment relative to said flexible distal end segment, rotation of said outer cutting window member relative to said flexible distal end segment, and rotation of said inner cutting member relative to said outer cutting window member; and

said independent degrees of freedom occur relative to a stationary position of said hollow shaft.

2. A surgical instrument according to claim 1 wherein said flexible distal end segment comprises a plurality of vertebrae which are interconnected with one another by at least one web.

3. A surgical instrument according to claim 2 wherein said at least one web deflects in the manner of a beam when subjected to bending forces.

4. A surgical instrument according to claim 2 wherein said plurality of vertebrae are interconnected with one another by two webs of the at least one web.

5. A surgical instrument according to claim 4 wherein said two webs are diametrically opposed from one another.

6. A surgical instrument according to claim 2 wherein said flexible distal end segment comprises a single, integral piece.

7. A surgical instrument according to claim 1 wherein said flexible distal end segment comprises at least one opening extending therethrough, and further wherein said at least one tensioning member extends through said at least one opening.

8. A surgical instrument according to claim 1 wherein said flexible distal end segment comprises at least one passageway extending therethrough, and further wherein said inner extension tube extends through said at least one passageway.

9. A surgical instrument according to claim 1 wherein said at least one tensioning member comprises two tensioning members.

10. A surgical instrument according to claim 9 wherein said two tensioning members each comprise a distal end and a proximal end, and further wherein said distal ends of said two tensioning members are secured to said distal end of said flexible distal end segment and said proximal ends of said two tensioning members extend to said handle.

11. A surgical instrument according to claim 9 wherein said two tensioning members are diametrically opposed from one another as they extend along said flexible distal end segment and said hollow shaft.

12. A surgical instrument according to claim 9 further comprising a bending cam mounted to said handle for selectively applying tension to said two tensioning members, and further wherein said proximal ends of said two tensioning members are secured to said bending cam.

13. A surgical instrument according to claim 1 further comprising a rotation control knob movably mounted to said handle, said proximal end of said inner extension tube being mounted to said rotation control knob.

14. A surgical instrument according to claim 13 wherein said rotational element comprises a flexible actuating cable.

15. A surgical instrument, said surgical instrument comprising:

a hollow shaft having a distal end and a proximal end;

a handle disposed at said proximal end of said hollow shaft;

a flexible distal end segment disposed at said distal end of said hollow shaft, said flexible distal end segment comprising a distal end and a proximal end, with said proximal end of said flexible distal end segment being mounted to said distal end of said hollow shaft;

at least one tensioning member extending between said distal end of said flexible distal end segment and said handle for manipulating said distal end of said flexible distal end segment relative to said hollow shaft whereby to provide curvilinear bending of said flexible distal end segment relative to said hollow shaft;

an outer cutting window member rotatably mounted to said distal end of said flexible distal end segment;

an inner extension tube extending through said hollow shaft and said flexible distal end segment for selectively rotating said outer cutting window member relative to said flexible distal end segment, said inner extension tube having a distal end and a proximal end, said distal end of said inner extension tube being mounted to said outer cutting window member and said proximal end of said inner extension tube extending to said handle;

at least one spring for yieldably biasing said inner extension tube proximally so as to yieldably bias said outer cutting window member proximally against said distal end of said flexible distal end segment;

an inner cutting member rotatably disposed within said outer cutting window member; and

a rotational element for rotating said inner cutting member relative to said outer cutting window member, said rotational element comprising a distal end connected to said inner cutting member and a proximal end extending to said handle;

wherein said surgical instrument is configured so as to provide at least the following independent degrees of freedom: curvilinear bending of said flexible distal end segment relative to said flexible distal end segment and a stationary position of said hollow shaft, rotation of said outer cutting window member relative to said flexible distal end segment and said stationary position of said hollow shaft, and rotation of said inner cutting member relative to said outer cutting window member and said stationary position of said hollow shaft.

16. A surgical instrument according to claim 15 wherein said at least one spring is disposed at said proximal end of said hollow shaft.

17. A surgical instrument according to claim 16 wherein said handle comprises a rotation control knob mounted to said proximal end of said inner extension tube, wherein said rotation control knob can be used to selectively rotate said outer cutting window member relative to said flexible distal end segment, and further wherein said at least one spring is mounted to said rotation control knob so as to yieldably bias said rotation control knob proximally, whereby to yieldably bias said inner extension tube proximally, whereby to yieldably bias said outer cutting window member proximally against said distal end of said flexible distal end segment.

18. A surgical instrument according to claim 15 wherein said at least one spring is disposed at said distal end of said hollow shaft.

19. A surgical instrument according to claim 18 wherein said hollow shaft comprises an inner flange, said inner extension tube comprises an outer flange, and further wherein said at least one spring is disposed between said inner flange of said hollow shaft and said outer flange of said inner extension tube so as to yieldably bias said inner extension tube proximally relative to said hollow shaft, whereby to yieldably bias said outer cutting window member proximally against said distal end of said flexible distal end segment.