Surgical file

1. A surgical file instrument comprising a surgical file having a shaft with a blade on one end thereof and a tang on the other end thereof, the blade defining a curved surface where an apex of the curved surface extends along a midline of the blade, the blade having an upper cutting surface and an underneath smooth surface,

a shield disposed in parallel relationship with said blade and dimensioned to the same width of said blade, the shield having a relatively planar main body and including an elongated dimple centrally formed in a longitudinal direction along the main body, wherein an apex of the elongated dimple extends along the midline of the shield and bears bearing against the underneath smooth surface of the blade such that contact between the surgical file and the elongated dimple maintains alignment between the blade and the shield during operation of the surgical file.

2. The surgical file instrument of claim 1 , wherein each of an opposing side edge of the planar main body extends longitudinally parallel to a longitudinal axis of the shield, each of the side edges being bent in an upward direction to bear against the underneath smooth surface of the blade.

3. The surgical file of claim 2 , wherein a height of each of the opposing side edges bearing against the underneath smooth surface of the blade is less than a height of the apex of the elongated dimple.

4. The surgical file of claim 2 , wherein the shield includes a distal edge that extends laterally between the opposing side edges of the shield, the distal edge being bent in an upward direction to bear against the underneath smooth surface of the blade.

5. The surgical file of claim 4 , wherein the elongated dimple does not extend to the distal edge of the shield.

6. The surgical file instrument of claim 1 , wherein the apex of the elongated dimple bears against the bears against said underneath smooth surface adjacent the apex of the blade,

wherein the elongated dimple includes side walls extending from either side of the dimple apex along a straight line and to the planar main body of the shield.

7. The surgical file instrument of claim 1 , wherein the upper cutting surface of the blade includes a plurality of radial projecting ring-like elements each defining a cutting edge at the top surface thereof.

8. The surgical file instrument of claim 7 , wherein the plurality of radial projecting ring-like elements includes a first radial projecting ring-like element having a first diameter and a second radial projecting ring-like element having a second diameter, the first diameter greater than the second diameter.

9. The surgical file instrument of claim 8 , wherein the second radial projecting ring-like element is located along the apex of the blade.

10. The surgical file instrument of claim 9 , wherein the first radial projecting ring-like element is located between the apex of the blade and one of a side edges of the blade.

11. The surgical file instrument of claim 1 , further including an outer tube casing, the outer tube casing including a central lumen, the surgical file extending therethrough, wherein the shield is coupled to a distal end of the outer tube casing.

12. The surgical file instrument of claim 1 , wherein the blade of the surgical file extends from the shaft at an angle of at least 30 degrees.

13. The surgical file of claim 12 , wherein the tang of the surgical file extends from the shaft at an angle at least 30 degrees such that the file and the tang are generally parallel.

14. A surgical file instrument including a surgical file assembly in combination with a motion converter,

the surgical file assembly including:

an outer tube casing,

a solid plastic rod insert extending within a central lumen of the outer tube casing, and

a surgical file extending through the solid plastic rod, the surgical file having a blade on one end and a tang on the opposite end, the distal end of said file extending beyond the distal end of said solid plastic rod insert and the tang extending beyond said solid plastic rod on the other end, the blade defining a curved surface where an apex of the curved surface extends along a midline of the blade,

a shield is coupled to and extends from a distal end of the outer tube casing, the shield defining a relatively planar main body with an elongated dimple centrally formed thereon extending in a longitudinal direction, the elongated dimple bearing against a smooth underneath surface of the blade;

a battery-operated motor for generating rotary motion; and

the motion converter including:

a planetary gear system rotary connected to said motor,

a cam with a cam slot operatively connected to said planetary gear system,

a drum disposed adjacent to said cam,

a follower operatively connected to said slot for imparting reciprocal motion to said drum,

a connector on said drum connected to said tang for imparting reciprocal motion to said surgical file,

whereby said elongated dimple maintains said blade in line and free from wobbling when in the reciprocating condition.

15. The surgical file instrument of claim 14 , wherein the side edges of said flatten portion are faired in an upward direction and engaging said underneath smooth surface.

16. The surgical file instrument of claim 15 including:

a casing for said planetary gear system, and

a pair of pins extending from casing and into an annular slot formed on said cam for absorbing thrust loads in said planetary gear system.