Surgical navigation instrument

1. An instrument for navigating a surgical device, the instrument defining a proximal end and comprising: a hollow shaft having a longitudinal axis, at least a portion of the hollow shaft comprising a flexible section; a handle at the proximal end of the instrument, the handle comprising a first handle portion and a second handle portion; an articulation surface positioned distally with respect to the first handle portion and the second handle portion, and positioned proximally with respect to the flexible section, the handle being polyaxially displaceable relative to the articulation surface and relative to the longitudinal axis of the hollow shaft; at least one tensioning element in operable communication with the handle and the flexible section to bend the flexible section in response to polyaxial displacement of the handle relative to the longitudinal axis of the hollow shaft; an outer sleeve extending from the first handle portion; and an inner sleeve extending from the second handle portion and into the outer sleeve, the inner sleeve axially displaceable relative to the outer sleeve between a distal locked position, in which the inner sleeve bears against the articulation surface to lock the flexible section in a fixed configuration, and a proximal unlocked position, in which the inner sleeve does not engage the articulation surface to allow the flexible section to bend in response to polyaxial displacement of the handle relative to the longitudinal axis of the hollow shaft.

2. The instrument of claim 1 , wherein the handle comprises at least one disc extending in a plane that is substantially perpendicular to the longitudinal axis of the hollow shaft.

3. The instrument of claim 1 , wherein the articulation surface comprises a rounded bearing surface.

4. The instrument of claim 1 , wherein the articulation surface comprises a spherical shaped surface.

5. The instrument of claim 1 , wherein the articulation surface comprises a sphere.

6. The instrument of claim 1 , wherein the at least one tensioning element comprises a first pair of cables that are diametrically opposed to one another relative to a diameter of the hollow shaft.

7. The instrument of claim 6 , wherein the at least one tensioning element further comprises a second pair of cables that are diametrically opposed to one another relative to said diameter of the hollow shaft.

8. The instrument of claim 7 , wherein the first and second pairs of cables are radially offset 90 degrees from one another relative to the diameter of the hollow shaft.

9. The instrument of claim 1 , wherein the at least one tensioning element extends inside the hollow shaft.

10. The instrument of claim 1 , wherein the flexible section comprises a first interlocking section and a second interlocking section.

11. The instrument of claim 10 , wherein each of the first interlocking section and second interlocking section has at least one pin and at least one socket.

12. The instrument of claim 11 , wherein each pin is substantially triangular shaped, and each socket is substantially triangular shaped.

13. The instrument of claim 11 , wherein the at least one pin on the first interlocking section has a circumferential width that increases as said at least one pin on the first interlocking section extends from an outer surface of the shaft to an inner surface of the shaft, so that said at least one pin on the first interlocking section becomes gradually wider toward the inner surface.

14. The instrument of claim 11 , wherein the at least one pin on the second interlocking section has a circumferential width that decreases as said at least one pin on the second interlocking section extends from an outer surface of the shaft to an inner surface of the shaft, so that said at least one pin on the second interlocking section becomes gradually narrower toward the inner surface.

15. The instrument of claim 10 , wherein the first and second interlocking sections are cut at opposing angles to create at least one inward angled surface and at least one outward angled surface, said at least one inward angled surface being adjacent to the at least one outward angled surface.

16. The instrument of claim 1 , wherein the handle is pivotable on the articulation surface to apply variable amounts of tension to the at least one tensioning element to bend the flexible section.

17. The instrument of claim 1 , wherein the instrument defines a longitudinal passage through the hollow shaft, the articulation surface and the handle, the longitudinal passage adapted to receive a surgical instrument shaft into the handle and direct said surgical instrument shaft to a distal end of the flexible section.

18. The instrument of claim 1 , wherein the outer sleeve and the inner sleeve are connected by a threaded engagement, and the first handle portion is rotatable relative to the second handle portion to axially displace the inner sleeve relative to the outer sleeve between the locked and unlocked positions.

19. The instrument of claim 18 , wherein the first handle portion is rotatable relative to the second handle portion about the longitudinal axis of the hollow shaft to axially displace the inner sleeve relative to the outer sleeve.

20. The instrument of claim 1 , wherein the at least one tensioning element is coupled to the outer sleeve to connect the handle in operable communication with the flexible section.

21. The instrument of claim 1 , wherein in the distal locked position, the inner sleeve does not engage the at least one tensioning element.

22. The instrument of claim 1 , wherein the outer sleeve is integrally attached to the first handle portion, and the inner sleeve is integrally attached to the second handle portion.