Arthroscopic devices and methods

1. A cutting member for use in a rotational cutting device, said cutting member comprising:

a ceramic body having cutting edges, said cutting body formed of a ceramic composite including alumina, zirconia and cerium, wherein the alumina has a grain size ranging between 0.5 micron-1.5 microns and the zirconia has a grain size ranging between 0.1 micron-1.0 micron, wherein the ceramic composite comprises no more than 25 wt % alumina but no less than 15 wt % alumina, no more than 85 wt % zirconia but no less than 75 wt % zirconia, and no more than 5 wt % cerium but no less than 1 wt % cerium.

2. The cutting member of claim 1 , wherein the alumina grain shape and zirconia grain shape are non-elongated.

3. The cutting member of claim 1 , wherein the alumina grain shape and zirconia grain shape are each substantially round.

4. The cutting member of claim 1 , wherein the ceramic has a fracture toughness of at least 10 Mpam 1/2 .

5. The cutting member of claim 1 , wherein the ceramic composite has a thermal expansion coefficient ranging from 4 ppm/° C. to 6 ppm/° C.

6. The cutting member of claim 1 , wherein the ceramic composite has a bulk density ranging from 5 to 7.

7. The cutting member of claim 1 , wherein the ceramic composite has at least 20 wt % of alumina.

8. The cutting member of claim 1 , wherein the ceramic composite has at least 80 wt % of zirconia.

9. The cutting member of claim 1 , wherein the ceramic composite has less than 5 wt % of cerium.

10. A medical device for cutting bone and soft tissue, said medical device comprising:

a shaft including a rotating component having a working end; and

a cutting member as in claim 1 , carried on the working end of the rotating component.

11. The medical device of claim 10 , further comprising an electrode on the working end of the shaft.

12. The medical device of claim 11 , wherein the electrode is disposed between cutting edges of the cutting member.

13. The medical device of claim 11 , wherein the cutting member has at least one window therein which opens to an interior channel in the shaft.

14. The medical device of claim 13 , wherein the interior channel is configured to removably connect to a negative pressure source.

15. The medical device of claim 11 , further comprising a motor configured to couple to the proximal end of the shaft to rotate the cutting member.

16. A medical device for cutting bone and soft tissue, said medical device comprising:

an elongated shaft having a longitudinal axis, a proximal end, and a distal end;

a cutting member with cutting edges rotatably attached to and extending distally from the distal end of the elongated sleeve, said cutting member formed of a ceramic composite including alumina and zirconia; and

a motor configured to couple to the proximal end of the sleeve to rotate the cutting member,

wherein the alumina has a grain shape which is round with a diameter ranging between 0.5 micron-1.5 microns,

wherein the zirconia has a grain shape which is round with a diameter ranging between 0.1 micron-1.0 micron,

wherein the ceramic composite comprises no more than 25 wt % alumina but no less than 15 wt % alumina, no more than 85 wt % zirconia but no less than 75 wt % zirconia, and no more than 5 wt % cerium but no less than 1 wt % cerium.

17. The medical device of claim 16 , wherein the ceramic composite has a fracture toughness of at least 10 Mpam 1/2 .

18. The medical device of claim 16 , wherein the ceramic composite has a thermal expansion coefficient ranging from 4 ppm/° C. to 6 ppm/° C.

19. The medical device of claim 16 , wherein the ceramic composite has a bulk density ranging from 5 to 7.

20. The medical device of claim 16 , wherein the cutting member carries an electrode.

21. The medical device of claim 16 , wherein the electrode is disposed between cutting edges of the cutting member.