Devices and methods for bone fixation using axial implants
The invention comprises a method for fixating bones in the foot by aligning the bones in their desired position, inserting a screw in the aligned bones, inserting at least one transverse element near the head or tip of the screw, and tightening the screw to compress the bones. The screw comprises a shaft having first and second ends with spirally wound screw threads beginning near the first end and extending along the shaft. Advantageously, the screw is cannulated and screw threads are formed on an interior surface of the cannulation. Illustratively, the transverse elements may be staples, open-ended washers, or open-ended nuts. Reduction instruments and drill guides used in the invention are also disclosed.
1. A method for compressing at least a first and second bones comprising:
aligning the first and second bones in a desired alignment;
inserting a screw member into a borehole extending through the aligned first and second bones, the screw member comprising an elongated body extending from a first end to a second end, wherein the elongated body includes threads near the first end and a head at the second end;
after inserting the screw member into the borehole, inserting a first transverse element into the first bone or the second bone transversely to a length of the screw member at a first position thereby engaging the elongated body of the screw member such that the screw member can be rotated with respect to the first transverse element; and
rotating the screw member to compress the first and second bones.
2. The method of claim 1 , wherein the first and second bones that are compressed are in a human foot.
3. The method of claim 1 , wherein the step of aligning the first and second bones comprises the step of: inserting a guide wire through the first and second bones.
4. The method of claim 1 , wherein the screw member is cannulated and the step of inserting the screw member into the borehole comprises:
mounting the screw member on a guide wire in the borehole; and
inserting the screw into the borehole on the guide wire.
5. The method of claim 1 , wherein the step of inserting the first transverse element at the first position comprises the steps of:
forming first and second holes through the first bone or the second bone, said first and second holes passing on either side of the screw member at the first position; and
inserting the first transverse element into the first and second holes.
6. The method of claim 1 further comprising the step of: inserting a second transverse element into the first bone or the second bone transversely to the length of the screw member at a second position.
7. The method of claim 6 , wherein the steps of inserting the first transverse element at the first position and inserting the second transverse element at the second position comprise the steps of:
drilling first and second holes through the first bone or the second bone, said first and second holes passing on either side of the screw at the first position;
drilling third and fourth holes through the first bone or the second bone, said third and fourth holes passing on either side of the screw at the second position;
inserting the first transverse element into the first and second holes; and
inserting the second transverse element into the third and fourth holes.
8. The method of claim 6 , wherein the first transverse element is inserted into the first bone, wherein the first transverse element engages the treads of the elongated body of the screw member at the first position, wherein the second transverse element is inserted into the second bone, wherein the second transverse element engages the second end of the elongated body of the screw member at the second position, and wherein rotating the screw member brings the first and second transverse elements closer together thereby compressing the first and second bones.
9. The method of claim 1 , wherein the first transverse element is a staple, open washer, or open nut.
10. The method of claim 1 , wherein the first transverse element comprises two spaced-apart legs connected using a middle portion, wherein the two spaced-apart legs engage the opposite sides of the elongated body of the screw member.
11. The method of claim 1 , wherein the first transverse element engages the threads of the screw member at the first position.
12. The method of claim 1 , wherein the first transverse element engages the elongated body near the second end.
13. The method of claim 1 , wherein the first transverse element engages the elongated body right below the head of the screw member.
14. The method of claim 1 , wherein the elongated body of the screw member comprises a recess that circumscribes the elongated body at the first position, and wherein the recess receives the first transverse element.
15. The method of claim 1 , wherein the threads of the elongated body engage the first bone, wherein the head of the elongated body engages the second bone, wherein the first transverse element is inserted into the first bone, wherein the first transverse element engages the threads of the elongated body of the screw member at the first position, and wherein rotating the screw member brings the head and the first transverse element closer together thereby compressing the first and second bones.
16. The method of claim 1 , wherein the threads of the elongated body engage the first bone, wherein the first transverse element is inserted into the second bone, wherein the first transverse element engages the elongated body near the second end at the first position, and wherein rotating the screw member compresses the first and second bones.
17. A method for compressing at least a first and second bones comprising:
aligning the first and second bones in a desired alignment;
forming a borehole through the aligned first and second bones;
inserting a screw member into the borehole;
attaching a guide element to the screw member;
using the guide element to drill first and second holes, said first and second holes passing on either side of the screw member at a first position transversely to a length of the screw member;
after inserting the screw member into the borehole, inserting a first transverse element into the first and second holes thereby engaging the elongated body of the screw member such that the screw member can be rotated with respect to the first transverse element; and
rotating the screw member to compress the bones.
18. The method of claim 17 further comprising the steps of:
using the guide element to drill third and fourth holes, said third and fourth holes passing on either side of the screw at a second position transversely to the length of the screw member; and
inserting a second transverse element into the third and fourth holes.
19. The method of claim 18 further comprising the step of: using the guide element at the first and/or second position to guide an osteotome in cutting bone around the screw.
20. The method of claim 17 , wherein the screw is cannulated and the step of inserting the screw member into the borehole comprises:
mounting the screw on a guide wire in the borehole; and
inserting the screw into the borehole on the guide wire.