Hook with rotating saddle and rotatable mono axial pedicle screw
View Patent ↗Disclosed herein are a hook with rotating saddle and a rotatable mono axial pedicle screw. In an embodiment, the disclosed hook may include at least one body comprising a hook member and a saddle member. The hook member and saddle member may be rotatably mounted to one another so as to rotate with respect to each other only about a common axis, and the saddle member may be configured for connection to an end of a connecting member. A surgical screw system may include receiver and screw members engagable with one another such that when engaged, only rotation of the receiving member about the longitudinal axis of the screw member and restrain against substantially all other translational or rotational movement.
1. A surgical hook apparatus comprising:
at least one body comprising a hook member and a saddle member, the hook member and the saddle member each provided with a cavity defined therein,
a compression member having a first diameter, the compression member being operable to be received within the cavity of the hook member and the cavity of the saddle member,
a set screw operable to be threaded within a connecting cavity defined in an upper portion of the cavity of the saddle member, and
a plurality of balls disposed in a channel defined in and between the hook member and saddle member, wherein the channel is sized to retain the balls,
wherein the hook member and saddle member are rotatably mounted to one another so as to rotate with respect to each other only about a common axis,
wherein the saddle member is configured to receive and connect to a first connecting member,
wherein the hook member is configured to receive and connect to a second connecting member,
wherein when the set screw is provided in engagement within the saddle member and against the first connecting member, the first connecting member is operable to allow the compression member to be disposed at a second diameter in outwardly-biased engagement with at least one of the hook member and the saddle member, the second diameter being greater than the first diameter,
wherein the outwardly-biased engagement compressively retains the plurality of balls in the channel so as to rotatably mount the hook member and saddle member to one another and to restrain against substantially all other translational or rotational movement between the hook member and the saddle member.
2. The surgical hook apparatus of claim 1 , wherein the saddle member is received within the cavity of the hook member.
3. The surgical hook apparatus of claim 2 , wherein the compression member comprises a spring that provides force outwardly upon the saddle member.
4. The surgical hook apparatus of claim 1 , wherein the first connecting member has a first end and a second end and is connected at its first end within the connecting cavity of the saddle member.
5. The surgical hook apparatus of claim 4 , further comprising a second body joined to a second end of the first connecting member.
6. The surgical hook apparatus of claim 1 , wherein the first or second connecting members are non-linear.
7. The surgical hook apparatus of claim 6 , wherein the first or second connecting members comprise a first segment, a second segment and a third segment,
wherein the first segment is connected to the second segment and the second segment is connected to the third segment, and
wherein the first segment is oriented substantially normal to the second segment and substantially parallel to the third segment.
8. The surgical hook apparatus of claim 6 , wherein the first or second connecting members comprise a first segment, a second segment and a third segment,
wherein the first segment is connected to the second segment and the second segment is connected to the third segment, and
wherein the first segment is oriented at a substantially 45 degree angle to the second segment and substantially parallel to the third segment.
9. The surgical hook apparatus of claim 1 , further comprising a pressure cap disposed in the cavity of the hook member, wherein:
the compression member further comprises a lower surface,
the pressure cap further comprises a shoulder extending outward from the lower region of the pressure cap, the shoulder having an upper surface substantially parallel with the lower surface of the compression member, and
when the set screw is provided in engagement within the saddle member and against the first connecting member, the force exerted on the saddle member by the first connecting member allows the lower surface of the compression member to contact the upper surface of the shoulder, such that when the set screw is tightened, contact between the lower surface and the upper surface of the shoulder allows the compression member to be disposed at the second diameter.
10. The surgical hook apparatus of claim 9 , the connecting cavity having one or more walls defined in the saddle member for receiving therein a first end of the first connecting member.
11. The surgical hook apparatus of claim 10 , wherein the walls are provided with threads for engagement with complementary threads provided on the first connecting member.
12. The surgical hook apparatus of claim 10 , further comprising a set screw mounted in a through hole defined in the hook member so as to bear against the second connecting member, such that when the set screw mounted in a through hole defined in the hook member is tightened, the position of the hook member relative to the saddle member is locked.