Pivoting spinal fixation devices
View Patent ↗Disclosed embodiments relate to connector systems comprising a linking element, a rod connection element partially received in the linking element. In an embodiment, the rod connection element is operable to rotate about the first longitudinal axis relative to the linking element. A fastener is operable to be received in the rod connection element, wherein the fastener is operable to actuate a connection mechanism to substantially fix the rod connection element in a rotational orientation relative to the first longitudinal axis and substantially fix the rod in a longitudinal position relative to the rod connection element.
1. An orthopedic connector system comprising:
a linking element having:
a rod-like cylindrical end portion operable to be securable within a pedicle screw; and
an aperture defined in a flat lower surface in an offset portion of the linking element offset from the end portion, the aperture extending along a first longitudinal axis;
a rod connection element having a solid lower portion and an upper portion operable to be received in the aperture, wherein the linking element is operable to rotate about the first longitudinal axis relative to the rod connection element and comprises:
an opening defined in the upper portion of the rod connection element, the opening extending longitudinally along and circumferentially about the first longitudinal axis; and
an elongated slot defined in the solid lower portion of the rod connection element, the elongated slot operable to seat a rod therein;
wherein the rod is operable to be received within the rod connection element from the opening in the upper portion to the elongated slot in the lower portion; and
a fastener operable to be received in the aperture of the linking element and the opening of the rod connection element, wherein
the fastener is operable to actuate a connection mechanism to substantially fix the linking element in a rotational orientation relative to the rod connection element about the first longitudinal axis and substantially fix the rod in a longitudinal position relative to the rod connection element.
2. The connector system of claim 1 , wherein the connection mechanism comprises:
a first compression force exerted by the fastener on the upper portion of the rod connection element against an inner wall of the offset portion to substantially fix the linking element in a rotational orientation relative to the rod connection element about the first longitudinal axis; and
a second compression force exerted by the fastener on the rod against the elongated slot to substantially fix the rod in a longitudinal position relative to the elongated slot.
3. The connector system of claim 2 , wherein the upper portion of the rod connection mechanism and the offset portion of the linking element comprise mating ridges defined therein, and the first compression force is operable to allow the mating ridges to engage each other.
4. The connector system of claim 1 , wherein the offset portion of the linking element comprises a ring disposed in a groove defined in an inner wall of the offset portion of the linking element, and the ring is operable to snap into a mating groove defined in the upper portion of the rod connection element.
5. The connector system of claim 4 , wherein the groove in the inner wall has a larger diameter than a diameter of the ring such that the ring is operable to expand into the groove in the inner wall as the linking element is placed over the rod connection element.
6. The connector system of claim 1 , wherein the upper portion of the rod connection element comprises outer recessed areas defined therein and extending circumferentially, the outer recessed areas operable to mate with an inner wall of the offset portion of the linking element.
7. The connector system of claim 1 , wherein the elongated slot is configured to have an undercut geometry that mates with a geometric profile of the rod.
8. The connector system of claim 7 , wherein the rod connection element comprises a latch proximate to the elongated slot.
9. The connector system of claim 1 , wherein the fastener comprises a set screw.
10. The connector system of claim 1 , wherein the rod connection element comprises tapering tabs extending upwardly from the upper portion of the rod connection element.
11. The connector system of claim 10 , wherein the tabs are operable to guide the linking element down to the upper portion of the rod connection element for engagement.
12. The connector system of claim 10 , wherein the tabs are operable to be broken off.
13. An orthopedic connector system comprising:
a linking element having:
a rod-like cylindrical end portion operable to be securable within a pedicle screw; and
an aperture defined in an offset portion of the linking element offset from the end portion, the offset defined by a flat lower surface, a flat upper surface, and an inner wall enclosing the aperture, the aperture extending along a first longitudinal axis;
a rod connection element having an upper portion operable to be received in the aperture defined by the inner wall, wherein the linking element is operable to rotate about the first longitudinal axis relative to the rod connection element and comprises:
an opening defined in the upper portion of the rod connection element, the opening extending longitudinally along and circumferentially about the first longitudinal axis; and
a tapered flexible lower portion operable to clamp onto a rod;
a fastener operable to be received in the opening of the rod connection element, wherein a rotation of the fastener is operable to effect a translation of the rod connection element upwardly towards the upper surface of the offset portion and a compression of the tapered flexible lower portion of the rod connection element against the inner wall of the offset portion of the linking element, the compression operable to substantially fix the linking element in a rotational orientation relative to the rod connection element about the first longitudinal axis and substantially fix the rod in a longitudinal position relative to the rod connection element;
wherein the rod connection element is operable to engage the rod via the tapered flexible lower portion before being received in the inner wall enclosing the aperture via the upper portion.
14. The orthopedic connector system of claim 13 , wherein the fastener comprises a head portion operable to latch against the upper surface of the offset portion and a body portion operable to be received in the opening of the rod connection element.
15. A method of assembling a connector system for connecting a medical fastener to a rod in an offset orientation, comprising:
connecting a rod connection element to an implanted construct rod, wherein the rod connection element is rotatable about an axis formed by the implanted construct rod after engaging the implanted construct rod;
providing a linking element having:
a rod-like cylindrical end portion operable to be securable within a pedicle screw; and
an aperture defined in an offset portion of the linking element offset from the end portion, the offset defined by a flat lower surface, a flat upper surface, and an inner wall enclosing the aperture, the aperture extending along a first longitudinal axis;
connecting the linking element the rod connection element, and the implanted construct rod such that an upper portion of the rod connection element is disposed in the aperture, wherein the linking element is circumferentially rotatable about the first longitudinal axis after the connecting;
positioning the linking element in a rotational orientation about the first longitudinal axis relative to the rod connection element;
disposing a fastener in the aperture of the linking element and an opening defined in the upper portion of the rod connection element, the opening extending longitudinally along and circumferentially about the first longitudinal axis; and
rotating the fastener to substantially fix the rotational orientation of the linking element relative to the rod connection element and substantially fix the rod in a longitudinal position relative to the rod connection element.
16. The method of claim 15 , wherein rotating the fastener causes:
a first compression force exerted by the fastener on the upper portion of the rod connection element against the inner wall of the offset portion to substantially fix the rotational orientation of the linking element relative to the rod connection element about the first longitudinal axis; and
a second compression force exerted by the fastener on the rod against an elongated slot of the rod connection element to substantially fix the rod in a longitudinal position relative to the elongated slot.
17. The method of claim 15 , wherein the rod connection element comprises a tapered flexible lower portion operable to clamp onto a rod, and the fastener comprising:
a head portion operable to latch against the upper surface of the offset portion; and
a body portion operable to be received in the opening of the rod connection element; and
wherein rotating the fastener causes a translation of the rod connection element upwardly towards the upper surface of the offset portion and a compression of the tapered flexible lower portion of the rod connection element against the inner wall of the offset portion, the compression operable to substantially fix the rotational orientation of the linking element relative to the rod connection element and substantially fix the rod in a longitudinal position relative to the rod connection element.
18. The method of claim 15 , wherein disposing the upper portion of the rod connection element in the aperture is performed before connecting the rod to the rod connection element.
19. The method of claim 15 , wherein disposing the upper portion of the rod connection element in the aperture is performed after connecting the rod to the rod connection element.
20. The method of claim 15 , wherein the fastener comprises a set screw.