Spinal connectors and related methods
In some embodiments, a connector can be configured to couple a first fixation element (e.g., a first rod) to a second fixation element (e.g., a second rod). One or both of the first and second fixation elements can be included with the connector, or one or both can be separately provided. In some instances, at least one of the fixation elements is previously implanted in a patient. The connector can provide one or more degrees of freedom between the first and second fixation elements. The connector can also include a locking element configured to (1) lock one or more of the fixation elements to the connector, and (2) lock one or more of the degrees of freedom between the fixation elements. The connector can be configured to snap onto or otherwise engage a fixation element in a manner that provides tactile and/or audible feedback to the surgeon.
1 . A connector, comprising:
a first spinal rod that extends along a length from a first end to a second end, the first spinal rod having a central opening formed thereon that is offset from the length at the first end thereof, the central opening defining a central longitudinal axis therethrough; and
a connection assembly having a clamp configured to receive a second spinal rod therein and a nut that engages the clamp to selectively lock an orientation of the first spinal rod relative to the connection assembly and an orientation of the connection assembly relative to the second spinal rod disposed within the clamp;
wherein the central opening is configured to rotatably couple the first spinal rod to the connection assembly, and
wherein the second spinal rod is received in the clamp at a location that is collinear with the central longitudinal axis of the central opening.
2 . The connector of claim 1 , wherein the nut is configured to: (1) lock the position and orientation of the connector relative to the second spinal rod; and (2) lock first and second rotational degrees of freedom of the first spinal rod relative to the second spinal rod.
3 . The connector of claim 1 , wherein the clamp further comprises a proximally-protruding stud portion and a distally extending pair of opposed arms coupled to one another at a hinge portion.
4 . The connector of claim 3 , wherein each of the opposed arms includes an inner surface for mating to the second spinal rod.
5 . The connector of claim 4 , wherein the opposed arms are configured to be positionable between an unlocked configuration in which a slot formed between the arms has substantially parallel sidewalls and the clamp is movable with respect to the second spinal rod disposed between the inner surfaces of the arms and a locked configuration in which the opposed arms are deflected towards one another about the hinge portion and in which the second spinal rod disposed between the inner surfaces of the arms is locked to the clamp to resist or prevent rotation or sliding movement of the second spinal rod relative to the clamp.
6 . The connector of claim 5 , wherein the second spinal rod is disposed between the inner surfaces such that a longitudinal axis A 3 of the second spinal rod extends perpendicular to a longitudinal axis of the stud portion and to a longitudinal axis along which the nut is advanced.
7 . The connector of claim 3 , wherein the stud portion further comprises a threaded surface on at least a portion thereof, the threaded surface being configured to threadably engage a corresponding thread formed on the nut to transition the connector between an unlocked configuration and a locked configuration.
8 . The connector of claim 3 , wherein the central opening is configured to receive at least a portion of the stud portion therethrough such that the central opening is rotatable about a central longitudinal axis of the stud portion until the nut is selectively locked.
9 . The connector of claim 8 , wherein the clamp is configured to be rotatable about a transverse axis A 2 of the central opening.
10 . The connector of claim 8 , wherein the clamp is configured to be rotatable about a longitudinal axis A 1 of the central opening.
11 . The connector of claim 3 , wherein the central opening is configured to allow positioning of the stud portion therein at a plurality of angles.
12 . The connector of claim 11 , wherein a longitudinal axis of the stud portion is collinear with the longitudinal axis of the central opening or the longitudinal axis of the stud portion extends at an oblique angle with respect to the longitudinal axis of the central opening.
13 . The connector of claim 1 , wherein the connection assembly further comprises a washer disposed between the clamp and the nut.
14 . The connector of claim 13 , wherein the central opening includes a lower surface configured to engage a shoulder formed on the clamp and an upper surface configured to engage the washer.
15 . The connector of claim 14 , wherein the upper surface includes first and second cylindrical protrusions with a plurality of teeth formed thereon that are configured to be engaged by corresponding surface features of the washer to lock a relative angle between the stud portion of the clamp and a ring-shaped structure formed integrally with the first spinal rod in which the central opening is defined about a transverse axis A 2 of the central opening.
16 . The connector of claim 1 , wherein at least the first spinal rod is bendable.
17 . A surgical method, comprising:
positioning a connector relative to a surgical site, the connector having:
at least a first spinal rod that extends from a first end to a second end, the first spinal rod having a central opening formed thereon that is offset from the length at the first end thereof, the central opening defining a central longitudinal axis therethrough; and
a clamp having an inner surface defined between a pair of opposed arms for mating to a second spinal rod therebetween at a location that is collinear with the central longitudinal axis of the central opening, and a nut;
positioning the second spinal rod between the inner surface;
rotating the first spinal rod to a desired position about one or more of a longitudinal axis A 1 of a ring-shaped structure formed integrally with the first spinal rod in which the central opening is defined, or a transverse axis A 2 of the ring-shaped structure; and
moving the clamp to a desired orientation with respect to the second spinal rod; and
engaging the clamp using the nut to selectively lock an orientation of the first spinal rod relative to the connector and an orientation of the connector relative to the second spinal rod disposed within the inner surface.
18 . The method of claim 17 , further comprising actuating the nut to: (1) lock the orientation of the connector relative to a second spinal rod; and (2) lock first and second rotational degrees of freedom of the first spinal rod relative to the second spinal rod.
19 . The method of claim 18 , wherein actuating the nut squeezes the ring-shaped structure of the first spinal rod into firm engagement with a shoulder of a stud portion that extends proximally from the clamp to resist or prevent the first spinal rod from rotating about the longitudinal axis A 1 of the ring-shaped structure or the transverse axis A 2 of the ring-shaped structure with respect to the stud portion.
20 . The method of claim 19 , further comprising retracting the nut proximally away from the shoulder to allow the arms to spread apart and move towards an unlocked configuration.
21 . The method of claim 19 , wherein the connector couples to the second spinal rod such that a longitudinal axis of the stud portion extends in an anterior-posterior direction relative to the surgical site in a patient.
22 . The method of claim 19 , wherein the connector couples to the second spinal rod such that a longitudinal axis of the stud portion extends in a medial-lateral direction relative to the surgical site in a patient.
23 . The method of claim 17 , wherein the second spinal rod comprises a previously-implanted spinal rod in the surgical site.