Spinal fixation device
View Patent ↗An enclosure device connecting a pedicle fixation device with an elongated spinal fixation member. The enclosure device can include an enclosure member and an elongated guide member affixed to the enclosure member and defining a fracture region for breaking off the guide member from the enclosure member. The enclosure member can have a spherical outer surface rotatably received within a receiver portion of the pedicle fixation device. The enclosure member can include an internal bore capable of slidably receiving the fixation member.
1. An enclosure device for connecting a pedicle fixation device with an elongated spinal fixation member, the enclosure device comprising:
an enclosure member having an outer surface and an internal bore adapted for slidably receiving the spinal fixation member, the enclosure member received within a U-shaped receiver portion of the pedicle fixation device; and
an elongated guide wire having a terminal end fixedly attached to a portion of the outer surface of the enclosure member to guide the enclosure member into the pedicle fixation device, the guide wire having a fracture region for breaking off the guide wire from the enclosure member, the fracture region dimensioned such that the portion of the guide wire that remains attached to the enclosure member after the guide wire breaks from the enclosure member is fully contained within the pedicle fixation device.
2. The enclosure device of claim 1 , wherein the fracture region is a region of reduced cross-section of the guide wire.
3. The enclosure device of claim 1 , wherein the fracture region is a region of reduced fracture resistance in torsion of the guide wire.
4. The enclosure device of claim 1 , wherein the fracture region is a region of increased stress concentration in torsion of the guide wire.
5. The enclosure device of claim 1 , wherein the fracture region is defined by rounded groove in the guide wire.
6. The enclosure device of claim 1 , wherein the fracture region is defined by sharp notch in the guide wire.
7. The enclosure device of claim 1 , wherein the fracture region is adjacent to enclosure member.
8. The enclosure device of claim 1 , wherein the outer surface of the enclosure member is substantially spherical.
9. The enclosure device of claim 8 , wherein the internal bore is cylindrical.
10. The enclosure device of claim 1 , wherein the enclosure member is resilient and includes a gap.
11. A pedicle fixation device comprising:
a U-shaped receiver portion having a transverse opening formed from a proximal-most end of the receiver portion to an area adjacent to a distal end of the receiver portion;
a resilient enclosure member having an outer surface and an internal bore, the enclosure member rotatably received within the receiver portion such that the internal bore is aligned with the transverse opening of the receiver portion, the internal bore slidably receiving a spinal fixation member; and
an elongated guide wire having a terminal end fixedly attached to a portion of the outer surface of the enclosure member for guiding the enclosure member into the receiver portion, the guide wire having a fracture region for breaking off the guide wire from the enclosure member.
12. The pedicle fixation device of claim 11 , wherein the outer surface of the enclosure member is substantially spherical and the internal bore of the enclosure member is cylindrical.
13. The pedicle fixation device of claim 12 , wherein the fracture region is a V-shaped notch.
14. A pedicle fixation device comprising:
a U-shaped receiver portion defining a transverse opening for receiving an elongated spinal fixation member;
an enclosure member having an outer surface, an internal bore and a gap, the enclosure member rotatably received within the receiver portion such that the internal bore is aligned with the transverse opening of the receiver portion;
an elongated guide wire having a terminal end fixedly attached to a portion of the outer surface of the enclosure member to guide the enclosure member into the receiver portion, the guide wire comprising a fracture region for breaking off the guide wire from the enclosure member; and
a cannulated locking member engageable with an inner surface of the receiver portion above the enclosure member, the locking member defining a bore, the guide wire passable through the bore of the locking member,
wherein the fracture region is dimensioned such that the portion of the guide wire that remains attached to the enclosure member after the guide wire breaks off is fully contained within the bore of the locking member.
15. The pedicle fixation device of claim 14 , further comprising an elongated fixation member slidably received through the internal bore of the enclosure member and extending along the transverse opening of the receiver portion.
16. The pedicle fixation device of claim 14 , wherein the outer surface of the enclosure member is substantially spherical.
17. The pedicle fixation device of claim 16 , wherein the internal bore of the enclosure member is cylindrical.
18. The pedicle fixation device of claim 17 , wherein the fracture region is a V-shaped notch.
19. The pedicle fixation device of claim 14 , wherein the receiver portion defines and a longitudinal opening, and further comprising a pedicle fastener passing through the longitudinal opening.