Hook with rotating saddle and rotatable mono axial pedicle screw
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 screw system, comprising:
a screw member having a head portion, a body portion and a longitudinal axis;
a receiver member having upper and lower portions;
wherein the upper portion is provided with a receiving slot defined therein for receiving a surgical rod;
wherein the receiver member is provided with a retaining means for engagement with the head portion of the screw member;
wherein the receiver member is mountable to the screw member by application of a force in a direction parallel to the longitudinal axis and towards the body portion so as to engage the retaining means with a receiving surface of the screw member;
and wherein when mounted to the head portion the retaining means and receiver member are positioned to slide about the receiving surface to allow rotation of the receiver member about only the longitudinal axis of the screw member and prevent other translational or rotational movement of the receiver member relative to the screw member.
2. The surgical screw system of claim 1 , wherein the retaining means comprises an annular gasket,
wherein a channel sized to the gasket is defined within a surface of one or more of the receiver member and the head portion,
and wherein when mounted to the head portion, the gasket is positioned to slide about the receiving surface of the screw member to permit rotation of the receiver member about only the longitudinal axis of the screw member but prevent all other translational or rotational movement of the receiver member relative to the screw member.
3. The surgical screw system of claim 1 , wherein the retaining means comprises an annular retaining ring.
4. The surgical screw system of claim 1 , further comprising a biasing member disposed between the receiver member and head portion, the biasing member being arranged to apply a retention force between the receiver member and head portion when the receiver member is mounted to the head portion.
5. The surgical screw system of claim 4 , wherein the biasing member is a coil spring or wave spring.
6. A surgical screw system, comprising:
a screw member having a head portion, a body portion and a longitudinal axis;
a receiver member having an upper portion, a lower portion, and a bottom;
wherein the upper portion is provided with a receiving slot defined therein for receiving a surgical rod;
a pressure cap engaged with the head portion of the screw and disposed to engage the surgical rod when the surgical rod is received in the slot;
a retaining means disposed between the head portion of the screw member and the bottom of the receiver member; and
a biasing member biasing the pressure cap toward the head portion of the screw member and biasing the head portion toward the retaining means, the retaining means and receiver member being configured to allow rotation of the receiver member about only the longitudinal axis of the screw member and prevent other translational or rotational movement of the receiver member relative to the screw member.
7. The surgical screw system of claim 6 , wherein when mounted to the head portion the retaining means is positioned to slide about a portion of the screw member to allow the receiver member to rotate only about the longitudinal axis of the screw member, and to prevent other translational or rotational movement of the receiver member relative to the screw member.
8. The surgical screw system of claim 6 , wherein the retaining means comprises an annular gasket,
wherein a channel sized to the gasket is defined within a surface of one or more of the receiver member and the head portion,
and wherein when mounted to the head portion, the gasket is positioned to slide about a receiving surface of the screw member, the gasket and receiver member permitting rotation of the receiver member about only the longitudinal axis of the screw member but restraining against all other translational or rotational movement of the screw member.
9. The surgical screw system of claim 6 , wherein the retaining means comprises an annular retaining ring.
10. The surgical screw system of claim 6 , wherein the biasing member is a coil spring or wave spring.
11. A surgical screw system, comprising:
a screw member having a head portion, a body portion and a longitudinal axis;
a receiver member having an upper portion and a lower portion;
wherein the upper portion is provided with a receiving slot defined therein for receiving a surgical rod;
an annular engagement feature engaged with one of an exterior surface of the head portion of the screw member and an interior surface of the receiver member;
wherein at least one of the receiver member and the head portion comprises an annular channel or annular receiving surface for engagement with the annular engagement feature;
wherein the receiver member is mountable to the screw member by application of a force in a direction parallel to the longitudinal axis and towards the body portion so as to engage the annular engagement feature with the annular channel or annular receiving surface;
and wherein when the head portion is mounted to the receiver member, the annular engagement feature is positioned to slide about the annular channel or annular receiving surface, the receiver member and annular engagement feature being configured to allow rotation of the receiver member about only the longitudinal axis of the screw member and prevent other translational or rotational movement of the receiver member relative to the screw member.
12. The surgical screw system of claim 11 , wherein the annular engagement feature comprises an annular gasket.
13. The surgical screw system of claim 11 , wherein the annular engagement feature comprises an annular retaining ring.
14. The surgical screw system of claim 11 , further comprising a biasing member or compression member situated between the receiver member and head portion, that applies a retention force between the receiver member and head portion when the receiver member is mounted to the head portion.
15. The surgical screw system of claim 14 , wherein the biasing member or compression member is a coiled spring or wave spring.