Externally threaded expandable orthopedic implant
An expandable screw for orthopedic insertion and expansion between a collapsed state and an expanded state. The screw has an upper externally-threaded body segment, a lower externally-threaded body segment opposite the upper external thread segments, and an expansion member extending along a longitudinal axis thereof. The expansion member connecting the upper externally-threaded body segment to the lower externally-threaded body segment, and configured during the expansion between the collapsed state and the expanded state to separate the upper externally-threaded body segment from the lower externally-threaded body segment.
1. An expandable screw for orthopedic insertion and expansion between a collapsed state and an expanded state, comprising:
an upper externally-threaded body segment;
a lower externally-threaded body segment opposite the upper externally-threaded body segment;
and
an expansion member extending along a longitudinal axis thereof, connecting the upper externally-threaded body segment to the lower externally-threaded body segment, and configured, during the expansion between the collapsed state and the expanded state, to separate the upper externally-threaded body segment from the lower externally-threaded body segment, the expansion member comprising a wedge member, an actuator, and a nose member having a distal end and a proximal end opposite the distal end, the nose member slidably connected to the upper externally-threaded body segment and the lower externally-threaded body segment, extending beyond the upper externally-threaded body segment and the lower externally-threaded body segment, and the nose member having external threads for engaging a bone segment of a patient, the external threads extending from the proximal end toward the distal end.
2. The screw of claim 1 , wherein the expansion member expands the upper externally-threaded body segment from the lower externally-threaded body segment in a single expansion direction.
3. The screw of claim 1 , wherein the expansion member expands the upper externally-threaded body segment from the lower externally-threaded body segment in a single expansion direction without a radial deflection of the upper externally-threaded body segment from the lower externally-threaded body segment.
4. The screw of claim 1 , wherein the expansion member expands the upper externally-threaded body segment from the lower externally-threaded body segment while the upper externally-threaded body segment and the lower externally-threaded body segment remain in a fixed orientation relative to each other.
5. The screw of claim 1 , wherein threads of the upper externally-threaded body segment and the lower externally-threaded body segment are each configured to secure the screw to a bone segment of a patient.
6. The screw of claim 1 , wherein at least one of the upper externally-threaded body segment and the lower externally-threaded body segment comprises an elongated body having an aperture.
7. The screw of claim 1 , wherein threads of the upper externally-threaded body segment and the lower externally-threaded body segment are each configured to secure the screw to a bone segment in a patient, and wherein the threads are disposed on outer peripheral sections of the upper externally-threaded body segment and the lower externally-threaded body segment.
8. An expandable screw for orthopedic insertion and expansion between a collapsed state and an expanded state, comprising:
an upper externally-threaded body segment;
a lower externally-threaded body segment opposite the upper externally-threaded body segment; and
an expansion member extending along a longitudinal axis thereof, connecting the upper externally-threaded body segment to the lower externally-threaded body segment, and configured, during the expansion between the collapsed state and the expanded state, to separate the upper externally-threaded body segment from the lower externally-threaded body segment, the expansion member comprising a wedge member, an actuator, and an externally threaded nose member having a distal end and a proximal end opposite the distal end, the nose member slidably connected to the upper externally-threaded body segment and the lower externally-threaded body segment and extending distally beyond the upper externally-threaded body segment and the lower externally-threaded body segment;
wherein threads of the upper externally-threaded body segment and the lower externally-threaded body segment are each configured to secure the screw to a bone segment in a patient,
wherein the threads are disposed on outer peripheral sections of the upper externally-threaded body segment and the lower externally-threaded body segment, and wherein at least one of the outer peripheral sections of one of the upper externally-threaded body segment and the lower externally-threaded body segment comprises a partially cylindrical shell.
9. The screw of claim 1 , wherein at least one of the upper externally-threaded body segment and the lower externally-threaded body segment comprises an elongated body having a partially cylindrical shape.
10. The screw of claim 9 , wherein the upper externally-threaded body segment, the lower externally-threaded body segment, and the external threads of the nose member are configured to secure the screw to the bone segment in the patient.
11. The screw of claim 1 , wherein the wedge member connects the upper externally-threaded body segment to the lower externally-threaded body segment; and wherein the actuator is disposed between the nose member and the wedge member, for translation of the wedge member along a longitudinal axis of the screw.
12. An expandable screw for orthopedic insertion and expansion between a collapsed state and an expanded state, comprising:
an upper externally-threaded body segment;
a lower externally-threaded body segment opposite the upper externally-threaded body segment; and
an expansion member extending along a longitudinal axis thereof, connecting the upper externally-threaded body segment to the lower externally-threaded body segment, and configured, during the expansion between the collapsed state and the expanded state, to separate the upper externally-threaded body segment from the lower externally-threaded body segment,
wherein the expansion member comprises:
a wedge member connecting the upper externally-threaded body segment to the lower externally-threaded body segment;
a nose member having a distal end and a proximal end opposite the distal end, the nose member slidably connected to the upper externally-threaded body segment and the lower externally-threaded body segment; and
an actuator disposed between the nose member and the wedge member, for translation of the wedge member along a longitudinal axis of the screw,
wherein the actuator, on a first side, is slidably connected to the nose member and, on a second side, is connected to the wedge member; and
wherein translation of the wedge member relative to the upper externally-threaded body segment and the lower externally-threaded body segment displaces the upper externally-threaded body segment and the lower externally-threaded body segment away from each other, thereby expanding the upper externally-threaded body segment away from the lower externally-threaded body segment.
13. The screw of claim 11 , wherein the expansion member further comprises: a pin coupling the actuator to the nose member.
14. The screw of claim 13 , wherein the pin maintains a position of the nose member relative to the actuator once the screw has been assembled.
15. The screw of claim 11 , wherein the actuator is threadably connected to the wedge member such that rotating the actuator translates the wedge member along the longitudinal axis.
16. The screw of claim 11 , wherein the wedge member comprises a first wedge and a second wedge connected together by a rail.
17. The screw of claim 11 , wherein dovetail grooves on the wedge member hold and slidably connect the upper externally-threaded body segment and the lower externally-threaded body segment to the wedge member.
18. The screw of claim 1 , wherein, in the expanded state, windows for bone graft filling are disposed between the upper externally-threaded body segment and the lower externally-threaded body segment.
19. A system comprising the expandable screw of claim 1 and an insertion tool configured to connect to the expandable screw for actuation and expansion of the expandable screw.
20. A method for utilizing an expandable screw for orthopedic insertion and expansion into a bone segment of a patient, the method comprising:
inserting the expandable screw of claim 1 into the bone segment of the patient; and expanding the expandable screw.
21. The screw of claim 1 , wherein, in the expanded state, elongated openings between the upper externally-threaded body segment and the lower externally-threaded body segment form windows for bone graft filling.