Steerable spine implants
A spine implant (e.g., for a TLIF surgical procedure) is configured to be steered into place during implantation in conjunction with a complementary insertion instrument. The cage of the implant is constrained to a limited range of rotation about a post carried by the cage. The insertion instrument is configured to hold the post while controllably rotating the cage relative to the post in order to angularly position the implant during implantation. Range of rotational motion is controlled by the configuration of a groove in the post. A retaining pin of the implant extends from the cage into the groove of the post to rotationally connect the cage to the post.
1. A spine implant comprising:
a post comprising a hole configured to receive a rod of an installation instrument;
a cage having an upper side, a lower side, a first lateral side, a second lateral side, a nose, a rear, and a central cavity, wherein the rear of the cage includes a first bore extending from the upper side towards the lower side, a second bore extending from the first lateral side into the first bore, and a radial slot providing access for the rod to attach to the hole in the post, wherein the post is inserted into the cage through the first bore such that the post is disposed in the rear of the cage and the cage is rotatable about the post; and
a retaining component received in the second bore of the cage and configured to engage the post to constrain the cage to a range of rotation about the post.
2. The spine implant of claim 1 , wherein:
the post has a radial groove of a given length about its exterior surface; and
the retaining component engages the radial groove, wherein range of rotational movement of the cage relative to the post is controlled by the given length of the radial groove of the post.
3. The spine implant of claim 2 , wherein the given length of the radial groove determines amount of cage angulation.
4. The spine implant of claim 2 , wherein the retaining component comprises a pin that is inserted in the second bore and at least partially disposed in the radial groove on the post.
5. The spine implant of claim 2 , wherein the radial slot is configured to allow the cage to pivot to one side relative to the post when the post is connected to the rod of the installation instrument that extends through the radial slot.
6. The spine implant of claim 5 , wherein the post is cylindrical, and the cage has a notch adjacent the rear that is configured to receive an angulation component of the installation instrument that controls angular position of the cage.
7. A kit for an interbody procedure, the kit comprising:
an implant comprising:
a post having an outer surface with a bore;
a cage having an upper side, a lower side, a first lateral side, a second lateral side, a nose, a rear, and a radial slot in the rear, the post disposed in the rear of the cage such that the cage is rotatable about the post and the bore of the post is accessible through the radial slot of the cage; and
a retaining pin received in the cage and in communication with the post to constrain the cage to a range of rotation about the post; and
an installation instrument comprising:
a first handle supporting a hollow shaft;
a rod extending through the hollow shaft and having a first end, a second end, and a knob on the second end, the first end of the rod configured to be received in the bore of the post through the slot in the rear of the cage, wherein manipulation of the knob engages and disengages the first end of the rod with and from the bore of the post; and
a sleeve extending about the hollow shaft and connected to a slidable first member disposed in a first outside groove of the hollow shaft, wherein rotation of the sleeve translates the first member, and wherein the position of the first member relative to the cage is configured to allow or inhibit the attached cage to rotate about the post;
wherein the installation instrument further comprises a second member opposite the slidable first member, and wherein the position of the slidable first member relative to the second member allows rotation of the cage about the post.
8. The kit of claim 7 , wherein the slidable first member is detained in the first outside groove of the hollow shaft via a dove-tailed configuration.
9. The kit of claim 7 , wherein the first pusher is detained in the first outside groove of the hollow shaft via a dove-tailed configuration.
10. The kit of claim 7 , wherein:
the post further comprises a radial groove of a given length about is exterior surface; and
the retaining pin is in communication with the radial groove, wherein range of rotational movement of the cage relative to the post is controlled by the given length of the radial groove of the post.
11. The kit of claim 10 , wherein the given length of the radial groove determines amount of cage angulation.
12. The kit of claim 7 , wherein:
the bore in the post is a threaded bore; and
the first end of the rod is threaded
the radial slot provides access to the threaded bore of the post to allow the threaded first end of the rod of the installation instrument to attach to the threaded bore of the post.
13. The kit of claim 7 , wherein the radial slot is configured to allow the cage to pivot to one side relative to the post when the post is connected to the first end of the rod of the installation instrument that extends through the radial slot.
14. The kit of claim 7 , wherein the cage has a notch adjacent the rear that is configured to receive an angulation component of the installation instrument that controls angular position of the cage.
15. A method of implanting an implant, the method comprising the steps of:
providing an implant comprising:
a post having an outer surface with a bore;
a cage having an upper side, a lower side, a first lateral side, a second lateral side, a nose, a rear, and a radial slot in the rear, the post disposed in the rear of the cage such that the cage is rotatable about the post and the bore of the post is accessible through the radial slot of the cage; and
a retaining component received in the cage and in communication with the post to constrain the cage to a range of rotation about the post;
providing an installation instrument for implanting the implant, the instrument comprising:
a first handle supporting a hollow shaft;
a rod extending through the hollow shaft and having a first end, a second end, and a knob on the second end, the first end of the rod configured to be received in the bore of the post through the radial slot in the rear of the cage, wherein manipulation of the knob engages or disengages the first end of the rod to and from the bore of the post; and
a sleeve extending about the hollow shaft and connected to a slidable first member disposed in a first outside groove of the hollow shaft, wherein rotation of the sleeve translates the slidable first member to allow or inhibit the attached cage to rotate about the post and change its angular position; and
steering the implant into a space using the installation instrument;
wherein the installation instrument further comprises a second member opposite the slidable first member, and wherein the position of the slidable first member relative to the second member allows or prevents rotation of the cage about the post.
16. The method of claim 15 , wherein:
the post further comprises a radial groove of a given length about is exterior surface; and
the retaining component is at least partially engaged with the radial groove, such that a range of rotational movement of the cage relative to the post is controlled by the given length of the radial groove of the post.
17. The method of claim 16 , wherein the given length of the radial groove determines amount of cage angulation.