Expandable spinal interbody spacer and method of use
An expandable spinal implant configured for positioning within a space between adjacent vertebral bodies includes an upper body, a lower body, a ratchet mechanism, and a plurality of bone screws. The upper body and lower body are pivotably affixed at a first end and are capable of movement relative to each other. The ratchet mechanism is slidably disposed on one of the upper and lower body and is capable of engaging the opposite one of the upper and lower body thereby permitting movement of the upper and lower body relative to each other in a first direction, but not in a second direction. An insertion instrument capable of being attached to the expandable spinal instrument and a method of performing spinal surgery is also disclosed.
1. A method of performing surgery, comprising:
positioning an upper body and a lower body of a spinal implant in a first, approximated position relative to each other, the upper body and lower body pivotably coupled at a first end and capable of movement relative to each other, wherein each of the upper body and the lower body is dimensioned to be installed between first and second vertebral bodies, the outer surfaces of each of the upper body and the lower body are adapted to engage a corresponding end plate of the first and second vertebral bodies;
preparing an intervertebral space between the first and second vertebral bodies to receive the spinal implant;
inserting the spinal implant into the prepared intervertebral space;
articulating the upper body and lower body relative to each other to effectuate a desired lordosis of a spine of the patient;
inserting a plurality of bone screws that are capable of being attached to bone through a plurality of screw holes defined through the outer surface and an adjacent side surface of the upper body and through the outer surface and an adjacent side surface of the lower body, wherein the screw holes are oriented towards a respective adjacent one of the first and second vertebral bodies at an oblique angle; and
locking a ratchet mechanism slidably disposed on one of the upper and lower bodies, to lock the position of the upper body and lower body relative to each other, the ratchet mechanism capable of engaging the opposite one of the upper and lower bodies thereby permitting movement of the upper and lower bodies relative to each other in a first direction, but not in a second direction.
2. The method of claim 1 , wherein inserting the spinal implant includes first securing the spinal implant to an insertion device.
3. The method of claim 1 , wherein locking the ratchet mechanism includes rotating a ratchet screw disposed within an annular groove defined within the upper body in a first direction, wherein the ratchet screw includes a head and a threaded shank extending therefrom, the ratchet screw being threadably engaged within a threaded through-bore defined through the ratchet mechanism, wherein rotating the ratchet screw effectuates movement of the ratchet mechanism in a first direction thereby causing the ratchet mechanism to engage the lower body and lock the position of the lower body relative to the upper body.
4. The method of claim 1 , wherein positioning the upper body and lower body in a first, approximated, position includes engaging a first plurality of teeth defined on a surface of the ratchet mechanism with a second plurality of teeth defined on an opposing surface of the lower body, thereby permitting articulation of the upper body relative to the lower body in a first direction, but not in a second direction.
5. The method of claim 4 , wherein locking the ratchet mechanism further includes further rotating the ratchet screw the first direction, thereby causing the first and second pluralities of teeth to further engage, thereby locking the position of the upper body and the lower body relative to each other.
6. The method of claim 1 , further including packing a lumen defined in each of the upper body and lower body with bone in-growth material.
7. The method of claim 1 , further including packing a lumen defined in each of the upper body and lower body with drugs.
8. The method of claim 1 , wherein positioning the upper body and lower body includes positioning the upper body and lower body in a desired articulated position relative to each other.
9. A method of treatment of a spinal condition, comprising:
inserting a spinal implant into an intervertebral space between a first vertebral body and a second vertebral body;
articulating an upper body and a lower body of the spinal implant relative to each other to a desired one of a plurality of articulated arrangements, the upper and lower bodies being positioned to define a different respective angle therebetween in each of the plurality of articulated arrangements;
after the step of articulating the upper and lower bodies, and while the upper and lower bodies are positioned in the desired articulated arrangement with the respective angle therebetween, actuating a locking mechanism of the spinal implant by moving the locking mechanism from an unlocked configuration to a locked configuration, so as to lock the positions of the upper and lower bodies relative to each other in the desired articulated arrangement with the respective angle therebetween; and
anchoring the spinal implant to the first and second vertebral bodies with a plurality of screws, at least a first one of the screws extending through an outer surface of the upper body and into the adjacent first vertebral body, and at least a second one of the screws extending through an outer surface of the lower body and into the adjacent second vertebral body.
10. The method of claim 9, wherein the first and second screws extend at an oblique angle through the outer surfaces of the respective upper and lower bodies.
11. The method of claim 9, wherein actuating the locking mechanism includes rotating a screw.
12. The method of claim 9, wherein the locking mechanism is disposed in the implant during the step of inserting the spinal implant into the intervertebral space.
13. The method of claim 9, wherein actuating the locking mechanism includes moving a portion of the locking mechanism into engagement with grooves formed in the upper body or the lower body to prevent articulating movement of the upper and lower bodies relative to each other in at least one direction.
14. The method of claim 13, wherein actuating the locking mechanism includes moving a ratchet mechanism into engagement with the grooves formed in the upper body or the lower body.
15. The method of claim 9, wherein inserting the spinal implant includes securing a proximal end of the spinal implant to an insertion instrument.
16. The method of claim 15, wherein, during the step of inserting the spinal implant into the intervertebral space, the upper and lower bodies of the spinal implant are arranged in an approximated configuration, such that a projecting portion of one of the upper and lower bodies at the proximal end of the spinal implant is received within a recessed portion of the other of the upper and lower bodies at the proximal end of the spinal implant.
17. The method of claim 15, wherein securing the proximal end of the spinal implant to the insertion instrument comprises securing the insertion instrument to at least one threaded bore in the proximal end of the spinal implant.
18. The method of claim 15, wherein articulating the upper body and the lower body relative to each other comprises articulating the upper and lower bodies about a hinge axis disposed at a distal end of the spinal implant.