Hinged Polyaxial Screw and methods of use
A bone-anchoring device is provided. The device may include a substantially rigid shaft having a threaded portion configured to engage bone. The bone-anchoring device may further include a head portion securely attached to the shaft and a cap portion having a hinged connection with the head portion. A substantially spherical cavity may be formed between the head portion and the cap portion.
1 . A bone-anchoring device, comprising:
a substantially rigid shaft having a threaded portion configured to engage bone;
a head portion securely connected to the shaft;
a cap portion having a hinged connection with the head portion; and
a substantially spherical cavity formed between the head portion and the cap portion.
2 . The device of claim 1 , further including a fastening device for securing the cap to the head.
3 . The device of claim 2 , wherein the hinged connection is located on a first side of the cap with respect to the spherical cavity, and the fastening device is located on a second side of the cap with respect to the spherical cavity.
4 . The device of claim 2 , wherein the hinged connection and the fastening device are located on the same side of the cap with respect to the spherical cavity.
5 . The device of claim 2 , wherein the fastening device includes a screw.
6 . The device of claim 2 , wherein the fastening device includes a bolt.
7 . The device of claim 2 , wherein the fastening device includes a press-fit fastener.
8 . The device of claim 1 , wherein the hinged connection includes a hinge fastener.
9 . The device of claim 8 , wherein the hinge fastener includes a screw.
10 . The device of claim 8 , wherein the hinge fastener includes a bolt.
11 . The device of claim 8 , wherein the hinge fastener includes a press-fit fastener.
12 . The device of claim 1 , wherein the head portion includes a lower edge forming greater than 180 degrees of the substantially spherical cavity.
13 . The device of claim 1 , wherein the head portion includes a lower edge forming less than or equal to 180 degrees of the substantially spherical cavity.
14 . The device of claim 1 , wherein the head portion is configured to form a snap-fit connection with a substantially spherical member.
15 . The device of claim 14 , wherein the head portion includes one or more grooves.
16 . The device of claim 14 , wherein the head portion is formed of a material selected from the group including titanium, a steel, cobalt-chrome, stainless steel, and a polymeric material.
17 . A bone-anchoring system, comprising:
an anchor, including:
a substantially rigid shaft having a threaded portion configured to engage bone;
a head portion securely connected to the shaft;
a cap portion having a hinged connection with the head portion; and
a substantially spherical cavity formed between the head portion and the cap portion; and
a substantially spherical member configured to engage a rod and to be securely disposed within the substantially spherical cavity.
18 . The system of claim 17 , further including a fastening device for securing the cap to the head.
19 . The system of claim 18 , wherein the hinged connection is located on a first side of the cap with respect to the spherical cavity, and the fastening device is located on a second side of the cap with respect to the spherical cavity.
20 . The system of claim 18 , wherein the hinged connection and fastening device are located on the same side of the cap with respect to the spherical cavity.
21 . The system of claim 18 , wherein the fastening device includes a screw.
22 . The system of claim 18 , wherein the fastening device includes a bolt.
23 . The system of claim 18 , wherein the fastening device includes a press-fit fastener.
24 . The system of claim 17 , wherein the hinged connection includes a hinge fastener.
25 . The system of claim 24 , wherein the hinge fastener includes a screw.
26 . The system of claim 24 , wherein the hinge fastener includes a bolt.
27 . The system of claim 24 , wherein the hinge fastener includes a press-fit fastener.
28 . The system of claim 17 , wherein the head portion includes a lower edge forming greater than 180 degrees of the substantially spherical cavity.
29 . The system of claim 17 , wherein the head portion includes a lower edge forming less than or equal to 180 degrees of the substantially spherical cavity.
30 . The system of claim 17 , wherein the head portion is configured to form a snap-fit connection with the substantially spherical member.
31 . The system of claim 30 , wherein the head portion includes one or more grooves.
32 . The system of claim 30 , wherein the head portion is formed of titanium.
33 . The system of claim 17 , wherein the substantially spherical member is configured to removably engage a rod.
34 . The system of claim 17 , wherein the substantially spherical member is configured to slidingly engage a rod.
35 . The system of claim 17 , wherein the substantially spherical member is configured to rigidly engage a rod.
36 . The system of claim 17 , wherein the substantially spherical member is configured to permanently engage a rod.
37 . The system of claim 17 , wherein the substantially spherical member rotates within the substantially spherical cavity of the anchor.
38 . The system of claim 17 , wherein the anchor is configured to be connected to the substantially spherical member at a range of angles with respect to the rod.
39 . The system of claim 17 , wherein the substantially spherical member is compressible.
40 . The system of claim 17 wherein the substantially spherical member comprises a ring.
41 . The system of claim 17 , wherein the substantially spherical member includes at least one notch.
42 . The system of claim 17 , wherein the substantially spherical member includes at least one surface gap.
43 . The system of claim 17 , wherein the rod is configured to treat a curvature of the spine.
44 . The system of claim 17 , wherein the rod is configured to facilitate spinal fusion.
45 . The system of claim 17 , wherein the rod is configured to secure an implantable treatment system.