Fusion plate with directional holes and implant system employing the same
A fusion plate for use in fusing two bones together can include directional fastener bores that restrict the angle at which the fasteners can be positioned when inserted through the fastener bores. The fusion plate can be used in conjunction with a spacer, which may include a cavity into which the fusion plate can rest. The fusion plate can be coupled to the spacer using a coupling mechanism.
1. An intervertebral implant comprising:
a spacer configured to fit between the opposing endplates of two vertebrae to promote fusion of the two vertebrae, the spacer comprising a proximal end including a recess defined at least in part by two opposing members that each extend in a proximal direction, each of the two opposing members comprising a sidewall including a convex curvature in a plane formed by the proximal end;
a fusion plate coupleable to the proximal end comprising:
a body portion comprising a forward face, a rearward face opposed to the forward face, and opposing concave lateral sidewalls extending from the forward face to the rearward face of the body portion, the opposing concave lateral sidewalls connecting a first extension and a second extension of the body portion;
the first extension including a first bore extending from the rearward face to the forward face; and
a first fastener extendable through the first bore to couple the implant to an endplate of a first vertebra;
wherein the body portion of the fusion plate is directly receivable between the two opposing members of the recess and the convex sidewalls of the two opposing members matingly engage the concave lateral sidewalls of the body portion of the fusion plate.
2. An implant configured to be interposed between opposing faces of two bones to be fused together, the implant comprising:
a spacer configured to fit between the opposing sides of the two bones to promote fusion of the two bones, the spacer comprising a forward portion, a rearward portion, a top, a bottom, and two side portions, the rearward portion comprising at least one cavity defined in part by two opposing members that each extend in a rearward direction, each of the two opposing members comprising a convex cavity sidewall, wherein the convex cavity sidewall includes a convex curvature in a plane formed by the rearward portion;
a fusion plate coupleable to the spacer comprising:
a main body portion comprising a forward face, a rearward face opposed to the forward face, and opposing concave lateral sidewalls extending from the forward face to the rearward face of the main body portion;
a first extension side portion comprising a forward face and a rearward face opposed to the forward face and extending away from a first side of the main body, wherein the first extension side portion is configured to extend beyond at least one of the top or the bottom of the spacer; and
a first bore in the first extension side portion extending from the rearward face to the forward face, the bore comprising
a first opening in the rearward face comprising a first diameter extending from a first side of the first opening closest to the main body to an opposing side of the first opening;
a second opening in the forward face comprising a second diameter extending from a first side of the second opening closest to the main body to an opposing side of the first opening; and
a throat portion located intermediate the first opening and the second opening and comprising a third diameter extending from a first side of the throat portion closest to the main body to an opposing side of the throat portion;
wherein the third diameter is shorter than the first diameter and the second diameter; and
a plurality of fasteners comprising at least a first fastener extendable through the first bore to exit out of the second opening and configured to couple the implant to an endplate of a first bone;
wherein the main body portion of the fusion plate is directly receivable between the two opposing members of the at least one cavity and the convex cavity sidewalls of the two opposing members matingly engage the concave lateral sidewalls of the main body portion of the fusion plate.
3. The implant of claim 2 , wherein the first diameter of the first opening has a first end proximate the main body and a second end opposite the first end and the second diameter of the second opening has a first end proximate the main body and a second end opposite the first end, and wherein the first end of the first diameter of the first opening is positioned closer to the main body than the first end of the second diameter and wherein the second end of the first diameter is positioned closer to the main body than the second end of the second diameter.
4. The implant of claim 2 , wherein:
the first bore includes a first side wall portion proximate the main body and a second side wall portion opposite the first side wall portion;
the first side wall portion includes an angled portion extending from the first opening to a first point intermediate the first opening and the second opening and a vertical wall portion extending from the first point to the second opening; and
the second side wall portion includes a vertical portion extending from the first opening to a second point intermediate the first opening and the second opening and an angled portion extending from the second point to the second opening.
5. The implant of claim 2 , wherein the spacer further comprises a spacer bore extending from the forward portion to the rearward portion and wherein the main body portion of the fusion plate further comprises a fusion plate bore extending from the forward face to the rearward face and the fusion plate is coupled to the spacer with a fastener that extends through the fusion plate bore and the spacer bore.
6. The implant of claim 5 , wherein the fusion plate bore and the spacer bore are coaxially aligned when the fusion plate is disposed in the cavity.
7. The implant of claim 2 , wherein the first bore limits movement of the at least one fastener extending therethrough in a direction perpendicular to a longitudinal axis of the fusion plate.
8. The implant of claim 2 , further comprising a recess formed in the rearward face of the main body and the first extension side portion and adapted for receiving a cover plate.
9. The implant of claim 4 , wherein the first side wall angled portion is oriented parallel with the second side wall angled portion.
10. The implant of claim 4 , wherein the second point is closer to the rearward face than the first point.
11. The implant of claim 2 , wherein the first extension side portion includes a second bore identical to the first bore.
12. The implant of claim 11 , wherein the second bore is located lateral to the second bore.
13. The implant of claim 2 , wherein the fusion plate further comprises a second extension side portion extending away from a second side of the main body portion that is opposite the first side of the main body portion.
14. The implant of claim 13 , wherein the second extension side portion comprises a first bore identical to the first bore in the first extension side portion.