Surgical universal positioning block and tool guide

1. A positioning block assembly for use in knee replacement surgery comprising:

a surgical tool guide block and a platform engaged to a guide body portion of the positioning block, the surgical tool guide block being slidingly displaceable along the platform, the surgical tool guide block having one of a rack and a pawl of a rack and pawl mechanism and the platform having the other of the rack and the pawl, and the surgical tool guide block having a transversely extending socket receiving a plunger therein, the plunger having said one of a rack and a pawl thereon;

an elastically deflectable blade spring disposed on the surgical tool guide block, the blade spring biasing one of the rack and the pawl such that they are normally engaged together, wherein the surgical tool guide block is slidingly displaceable on the platform when the rack and pawl are disengaged, and fixed relative to each other when the rack and pawl are in engagement; and

the surgical tool guide block and the platform having substantially seamless surfaces that are at least one of substantially exposed and exposable, such that the surfaces can be pressure cleaned and autoclaved to remove biological matter therefrom.

2. The surgical instrument as defined in claim 1 , wherein the platform includes the toothed rack thereon and the surgical tool guide block includes the pawl.

3. The surgical instrument as defined in claim 2 , wherein the pawl is normally biased by the blade spring such that it is in engagement with the toothed rack on the platform.

4. The surgical instrument as defined in claim 3 , wherein the blade spring is integral with the surgical tool guide block.

5. The surgical instrument as defined in claim 4 , wherein the blade spring is formed by two parallel slots disposed in the surgical tool guide block and defining the blade spring therebetween.

6. The surgical instrument as defined in claim 3 , wherein the surgical tool guide block comprises an integral solid stop for protecting the blade spring and limiting displacement thereof.

7. The surgical instrument as defined in claim 1 , wherein the plunger has an integral retention member for retaining the plunger captive within the socket, while nevertheless permitting complete removal of the plunger from the socket when required for cleaning purposes.

8. The surgical instrument as defined in claim 1 , wherein the blade spring has a fixed and a free end, and is engaged at the fixed end to the surgical tool guide block such that the blade spring intersects the socket, permitting the plunger to contact the blade spring near the free end thereof.

9. A positioning block for use in total knee replacement surgery, permitting five degrees-of-freedom movement relative to a bone element to which it is fixed, the positioning block comprising:

a rotational mounting element being removably engageable to the bone element such that the mounting element is selectively rotatable relative to the bone element about at least three substantially perpendicular axes of rotation;

a guide body portion being engaged with the rotational mounting element such that it is translatable relative thereto along a proximal-distal axis and an anterior-posterior axis, while being rotationally fixed relative to the mounting element such that the guide body portion and the mounting element rotate together relative to the bone element; and

a surgical tool guide block engaged to the positioning block, the surgical tool guide block being displaceable on a platform engaged to the guide body portion of the positioning block and which provides support for the surgical tool guide block such that sliding displacement of the surgical tool guide block thereon is permitted, the platform including a toothed rack thereon and the surgical tool guide block having an elastically deflectable blade spring, the surgical tool guide block having a transversely extending socket receiving a plunger therein having a pawl, the pawl being normally biased by the blade spring such that it is in engagement with the toothed rack on the platform, the surgical tool guide block being displaceable relative to the platform when the biased pawl is disengaged from the toothed rack and fixed relative thereto when the pawl is engaged with the toothed rack.

10. The positioning block as defined in claim 9 , wherein the surgical tool guide block and the platform have substantially seamless surfaces that are at least one of substantially exposed or exposable, such that the surfaces are easily pressure cleaned and autoclaved to remove biological matter therefrom.

11. The positioning block as defined in claim 9 , wherein the blade spring is integral with the surgical tool guide block.

12. The positioning block as defined in claim 11 , wherein the blade spring is formed by two parallel slots disposed in the surgical tool guide block and defining the blade spring therebetween.

13. The positioning block as defined in claim 9 , wherein the surgical tool guide block comprises an integral solid stop for protecting the blade spring and limiting displacement thereof.

14. The positioning block as defined in claim 9 , wherein the plunger has an integral retention member for retaining the plunger captive within the socket, while nevertheless permitting complete removal of the plunger from the socket when required for cleaning purposes.

15. The positioning block as defined in claim 9 , wherein the blade spring has a fixed and a free end, and is engaged at the fixed end to the surgical tool guide block such that the blade spring intersects the socket, permitting the plunger to contact the blade spring near the free end thereof.