ALIF spine implant with cam screws for inhibiting bone anchor backout
A spine implant for an ALIF procedure includes anchoring members being either a bone screw or flexible barb, each having a head on one end of a shaft, and a tip on another end of the shaft. The spine implant includes a porous cage having a front, rear, central cavity, and three angled bores in the front that extend into the central cavity configured to receive one of the plurality of anchoring members such that the tip of the anchoring member extends from one or another side of the cavity with its head retained in the front. The spine implant further includes two retention members configured for insertion into the front such that a portion of the two retention members are positioned over the heads of two, adjacent anchoring members to inhibit bone anchor backout via cam action between the retention member and the heads of the anchoring members.
1. A spine implant for an ALIF procedure, the spine implant comprising:
a plurality of anchoring members each having a shaft, a head on one end of the shaft, and a tip on another end of the shaft;
a porous cage having a front, a rear, a central cavity, an upper surface, a lower surface, a first angled bore in a first lateral side of the front that extends into the central cavity, a second angled bore in a second lateral side of the front that extends into the central cavity, and a third angled bore in the front between the first angled bore and the second angled bore that extends into the central cavity, the first angled bore extending from proximate the upper surface to through the lower surface, the second angled bore extending from proximate the upper surface to through the lower surface, and the third angled bore extending from the lower surface to through the upper surface, wherein each of the first, second, and third angled bores is configured to receive one of the plurality of anchoring members therethrough in a manner such that the tips of the anchoring members are directed out of the cavity; and
two retention members each having a retention member head and configured for insertion into the front in a manner such that at least a portion of the retention member heads of each retention member is located over the head of adjacent anchoring members, and wherein the retention member head of each retention member is further configured to inhibit backout of the adjacent anchoring members in the porous cage via cam action onto the heads of the adjacent anchoring members.
2. The spine implant of claim 1 , wherein the retention members further include a retention member shaft, and wherein an underside portion of each retention member head rests upon the heads of the adjacent anchoring members.
3. The spine implant of claim 2 , wherein each retention member head further includes two opposing sides that are greater in length than remaining sides of the retention member head.
4. The spine implant of claim 2 , wherein the front further includes a first threaded retention member receiving portion located between the first angled bore and the third angled bore, wherein the threaded retention member receiving portion is configured to receive and retain a threaded distal end of the retention member therein.
5. The spine implant of claim 4 , further comprising a second threaded retention member receiving portion located between the second angled bore and the third angled bore, and wherein the second threaded retention member receiving portion is configured to receive and retain a second retention member therein.
6. The spine implant of claim 1 , wherein the porous cage has a first lateral side and a second lateral side that are both unitary with the front and the rear of the porous cage.
7. The spine implant of claim 6 , wherein the first and the second lateral sides contain windows.
8. The spine implant of claim 1 , wherein the plurality of anchoring members further comprise barb-type anchoring members.
9. The spine implant of claim 1 , wherein the porous cage consists of titanium alloy.
10. The spine implant of claim 1 , wherein the head of each anchoring member is located near the front of the porous cage and the tip of each anchoring member is located closer toward the rear of the porous cage, being angled away from the porous cage.