Bone screw with selectively securable washer

Abstract

A screw assembly (10) for insertion into a bone region (12A) (12B) includes a screw body (14) and a washer (16). The screw body (14) includes a distal end (218), a proximal end (224), and a distal threaded area (220), and a proximal threaded area (226). The distal threaded area (220) is positioned near the distal end (218) and the proximal threaded area (226) is positioned near the proximal end (224). The washer (16) includes a washer threaded area (238) that engages the proximal threaded area (226) to selectively secure the washer (16) to the screw body (14). With this design, the washer (16) can be selectively attached to the screw body (14) and different sized washers (16) can be alternatively and selectively secured to the screw body (14). As a result thereof, the person inserting the screw assembly (10) can pick the washer (16) size best suited to retain the bone region (12A) (12B) in which the screw assembly (10) is being inserted.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of this invention, as well as the invention itself, both as to its structure and its operation, will be best understood from the accompanying drawings, taken in conjunction with the accompanying description, in which similar reference characters refer to similar parts, and in which:

FIG. 1 is a simplified side illustration of a pair of bone regions, in cut-away, that are fused together with a compression screw assembly having features of the present invention;

FIG. 2A is a side view of the screw assembly of FIG. 1;

FIG. 2B illustrates a side view of the washer;

FIG. 2C illustrates an end view of the washer;

FIG. 2D illustrates a cut-away view of the washer 16 taken on line 2D-2D in FIG. 2C;

FIG. 2E is a cut-away view taken on line 2E-2E from FIG. 2A;

FIGS. 2F and 2G are alternative cut-away views of a portion of the screw assembly;

FIG. 3A is a perspective view of a second embodiment of a screw assembly having features of the present invention;

FIG. 3B is a side view of the screw assembly of FIG. 3A;

FIG. 3C is a side view of a screw body;

FIG. 3D is a cut-away view taken on line 3D-3D of FIG. 3B;

FIGS. 3E and 3F are alternative cut-away views of a portion of the screw assembly;

FIG. 4A is a perspective view, and FIG. 4B is an exploded perspective view of another embodiment of a screw assembly having features of the present invention;

FIG. 5 is a perspective view of yet another embodiment of a screw assembly having features of the present invention;

FIG. 6A is a perspective view, and FIG. 6B is an exploded perspective view of still another embodiment of a screw assembly having features of the present invention;

FIGS. 7A and 7B are alternative perspective views of another embodiment of a screw assembly having features of the present invention;

FIGS. 8A and 8B are alternative perspective views of yet another embodiment of a screw assembly having features of the present invention;

FIG. 9A is a perspective view, FIG. 9B is an end view, FIG. 9C is a side view, and FIG. 9D is a cut-away view of still another embodiment of a screw assembly having features of the present invention;

FIGS. 10A-10C are alternative views of a washer having features of the present invention;

FIGS. 11A and 11B are alternative views of a screw body having features of the present invention; and

FIGS. 12A and 12B are alternative views of another embodiment of a screw body having features of the present invention.

Claims

1. A screw assembly for insertion into a bone region, the screw assembly comprising: a screw body including a distal end, an opposed proximal end, and a distal threaded area that is positioned near the distal end; anda washer that engages the screw body near the proximal end to selectively and fixedly secure the washer to the screw body.

2. The screw assembly of claim 1 wherein the screw body includes a proximal threaded area positioned near the proximal end, and the washer includes a washer threaded area that engages the proximal threaded area to selectively secure the washer to the screw body.

3. The screw assembly of claim 2 wherein the proximal threaded area includes an externally threaded surface and the washer threaded area includes an internally threaded surface.

4. The screw assembly of claim 2 wherein the proximal threaded area has a PTA length that is greater than a washer thickness of the washer.

5. The screw assembly of claim 4 wherein the washer is selectively locked onto the proximal threaded area with a portion of the proximal threaded area exposed for engaging the bone region.

6. The screw assembly of claim 2 wherein the proximal threaded area includes a threaded BT region that engages the bone region, and a threaded WT region that is engaged by the washer threaded area, the threads of the BT region being different from the threads of the WT region.

7. The screw assembly of claim 1 wherein the washer includes a washer slit that allows the washer to be slid onto the washer body from a side of the washer body.

8. The screw assembly of claim 1 wherein the washer includes at least one washer tooth that facilitates cutting by the washer into the bone region.

9. The screw assembly of claim 1 wherein the washer includes a washer fill region that provides an area for bone growth from the bone region.

10. The screw assembly of claim 1 wherein at least one of the screw body and the washer includes a tapered area so that washer fixedly engages the screw body.

11. A screw assembly for insertion into a bone region, the screw assembly comprising: a screw body including a distal end, an opposed proximal end, and a distal threaded area that is positioned near the distal end; anda washer combination including a first washer having a FW outer diameter and a second washer having a SW outer diameter that is larger that the FW outer diameter, wherein each of the washers can be alternatively and selectively secured to the screw body near the proximal end.

12. The screw assembly of claim 11 wherein each of the washers can be alternatively threaded onto the screw body.

13. The screw assembly of claim 12 wherein the first washer includes a washer threaded area that is substantially identical to a washer threaded area of the second washer.

14. The screw assembly of claim 12 wherein screw body includes an externally threaded proximal threaded area and each washer includes an internally threaded washer threaded area that engages the proximal threaded area.

15. The screw assembly of claim 14 wherein the proximal threaded area has a PTA length that is greater than a washer thickness of the washer.

16. The screw assembly of claim 14 wherein the washer is selectively locked onto the proximal threaded area with a portion of the proximal threaded area exposed for engaging the bone region.

17. The screw assembly of claim 12 wherein the proximal threaded area includes a threaded BT region that engages the bone region, and a threaded WT region that is engaged by the washer threaded area, the threads of the BT region being different from the threads of the WT region.

18. The screw assembly of claim 11 wherein at least one of the washers includes at least one washer tooth that facilitates cutting by that washer into the bone region.

19. The screw assembly of claim 11 wherein at least one of the washers include a washer fill region that provides an area for bone growth from the bone region.

20. The screw assembly of claim 11 wherein at least one of the screw body and the washers includes a tapered area so that the washers can be alternatively and selectively secured to the screw body near the proximal end.

21. A method of engaging a bone region, the method comprising the steps of: providing a screw body including a distal end, an opposed proximal end, a distal threaded area positioned near the distal end;fixedly securing a washer to the screw body near the distal end; andinserting the screw body into the bone region.

22. The method of claim 21 wherein the step of providing a screw body includes the screw body having a proximal threaded area, and the step of fixedly securing includes the step of threading the washer onto the proximal threaded area.

23. The method of claim 21 wherein the step of providing a screw body includes the screw body having a proximal tapered area, and the step of fixedly securing includes the step of pushing the washer onto the proximal tapered area.

24. The method of claim 21 wherein the step of fixedly securing includes the step of pushing a washer tapered area of the washer onto the screw body near the proximal end.