INTERVERTEBRAL MEMBERS AND METHODS OF USING A BONE REINFORCING COMPOSITION FOR RETAINING THE INTERVERTEBRAL MEMBERS
A method for dispensing a bone reinforcement composition into an intervertebral spacer and at least one adjacent vertebra can help retain the implant in situ. A cannula guide is inserted into a first vertebra guided by a live imaging system. A curved directional composition delivery cannula is inserted through a tubular body of the guide; then positioning the delivery cannula along a desired path, positioning an end using a curved end as a steering mechanism. The delivery cannula passes through a first vertebra, into the intervertebral spacer, and optionally into a second vertebra. A volume of reinforcement composition is dispensed using cyclical steps of incrementally withdrawing the delivery cannula and dispensing of the reinforcement composition until the path is filled with reinforcement composition stabilizing the respective vertebrae and/or interbody devices relative to each other. In an alternate arrangement, the cannula is inserted through a guide integrated into the spacer.
1 . A spinal implant system, comprising:
an implant assembly configured to deliver bone cement into an upper vertebra of a subject and a lower vertebra of the subject, the implant assembly including
an intervertebral body having a bifurcated throughhole, wherein the bifurcated throughhole includes an upper opening and a lower opening, and
a hollow upper anchor configured to be inserted into the upper opening and a hollow lower anchor configured to be inserted into the lower opening to define a continuous bone cement flow path extending along the hollow upper anchor, the hollow lower anchor, and the bifurcated throughhole such that bone cement flows along the continuous bone cement flow path for rigidly locking the spinal implant system together after the hollow upper anchor is positioned in the upper vertebra, the hollow lower anchor is positioned in the lower vertebra, and the intervertebral body is positioned between the upper vertebra and the lower vertebra.
2 . The spinal implant system of claim 1 , wherein
the intervertebral body includes a side wall, wherein the upper opening and the lower opening extend away from the side wall;
the hollow upper anchor is configured to be inserted through the upper opening such that the hollow upper anchor extends into the upper vertebra; and
the hollow lower anchor is configured to be inserted through the lower opening such that the hollow lower anchor extends into the lower vertebra;
the intervertebral body and the hollow upper anchor and the hollow lower anchor define the continuous bone cement flow path such that bone cement flows out of the hollow upper anchor into the upper vertebra, flows out of the hollow lower anchor into the lower vertebra, and forms a continuous cement structure extending through
the hollow upper anchor,
a portion of the intervertebral body between the hollow upper anchor and the hollow lower anchor, and
the hollow lower anchor.
3 . The spinal implant system of claim 1 , wherein at least one of the hollow upper anchor or the hollow lower anchor includes a head and a tubular sidewall, wherein the tubular sidewall has one or more delivery outlets that are positioned outside of the intervertebral body when the head is seated against the intervertebral body.
4 . The spinal implant system of claim 1 , wherein the continuous bone cement flow path extends along an upper passageway of the hollow upper anchor, through a central chamber of the intervertebral body, and along a lower passageway of the hollow lower anchor.
5 . The spinal implant system of claim 1 , wherein
the hollow upper anchor is configured to extend upwardly past a lower endplate of the upper vertebra when the intervertebral body contacts the lower endplate; and
the hollow lower anchor is configured to extend downwardly past an upper endplate of the lower vertebra when the intervertebral body contacts the lower endplate.
6 . The spinal implant system of claim 1 , wherein one or both of the hollow upper anchor and the hollow lower anchor includes through-holes through which the bone cement is capable of flowing to laterally exit the one or both of the hollow upper anchor and the hollow lower anchor.
7 . The spinal implant system of claim 1 , wherein the hollow upper anchor is a first upper anchor, and the hollow lower anchor is a first lower anchor, the spinal implant system further including:
a second upper anchor configured to extend into the upper vertebra; and
a second lower anchor configured to extend into the lower vertebra,
wherein a continuous flow passageway extends through the first upper anchor and the second upper anchor, through the first lower anchor and the second lower anchor, and through a portion of an anchor-receiving bifurcated fixation hole of the intervertebral body, thereby rigidly locking the spinal implant system together after implantation in the subject.
8 . The spinal implant system of claim 1 , wherein the intervertebral body is an intervertebral cage including
a bone-cement flow-through porous region; and
a bone graft receiving region that is configured to hold bone graft material while the bone cement flows through the bone-cement flow-through porous region.
9 . The spinal implant system of claim 1 , further comprising:
a delivery device including a pump and a delivery cannula fluidically connected to the pump, wherein the pump is operable to drive the bone cement through and out of the delivery cannula positioned in the implant assembly.
10 . The spinal implant system of claim 9 , wherein the delivery device is configured to hold and dispense a therapeutically effective amount of the bone cement to therapeutically reinforce the at least one of the upper vertebra or the lower vertebra.
11 . The spinal implant system of claim 9 , wherein a distal portion of the delivery cannula is configured to be moved through a passageway of at least one of the hollow upper anchor or the hollow lower anchor.
12 . The spinal implant system of claim 9 , wherein the delivery device is configured to expel the bone cement while being moved proximally along the continuous bone cement flow path.
13 . The spinal implant system of claim 1 , wherein the intervertebral body includes bifurcated fixation hole, an upper opening for facing the upper vertebra, and a lower opening for facing a lower vertebra, wherein the bifurcated fixation hole includes an angled passageway having a generally V-shaped configuration for connecting the upper opening to the lower opening through a central chamber of the intervertebral body.
14 . The spinal implant system of claim 1 , wherein the hollow upper anchor and the hollow lower anchor each include a curved segment configured to follow an arcuate path when inserted into the respective upper vertebra and lower vertebra.
15 . The spinal implant system of claim 1 , wherein the intervertebral body has a first porous region with a first average porosity and a second porous region with a second average porosity different from the first average porosity.
16 . The spinal implant system of claim 15 , wherein a ratio of the first average porosity to the second average porosity is greater than 2 .
17 . The spinal implant system of claim 15 , wherein the first porous region is an outer region and the second porous region is inside region, and wherein the first average porosity is substantially less than the second average porosity.
18 . The spinal implant system of claim 1 , further comprising:
a delivery device including a pump and a delivery cannula fluidically connected to the pump, wherein the pump is operable to cause the delivery device to eject cement through a hole in the delivery cannula, wherein the delivery cannula is rotatable within a passageway of one of the hollow upper anchor or the hollow lower anchor to direct cement through a specific hole in the one of the hollow upper anchor or the hollow lower anchor.
19 . A spinal implant system, comprising:
an implant assembly configured to deliver bone cement into an upper vertebra of a subject and a lower vertebra of the subject, the implant assembly including
an intervertebral body including interconnected passageways extending from an upper opening facing the upper vertebra and a lower opening facing the lower vertebra, the interconnected passageways defining a continuous bone cement flow path along which the bone cement flows between the upper opening and the lower opening and through the intervertebral body.
20 . The spinal implant system of claim 19 , wherein the interconnected passageways include a bifurcated fixation hole configure to receive a plurality of bone anchors.
21 . The spinal implant system of claim 19 , wherein the interconnected passageways includes
an upper passageway extending from the upper opening to a sidewall face of the intervertebral body, and
a lower passageway extending from the lower opening to the sidewall face of the intervertebral body.
22 . The spinal implant system of claim 21 , wherein
the intervertebral body is configured to be positioned between the upper vertebra and the lower vertebra and includes a side wall, wherein the bifurcated fixation hole extends from the side wall and includes an upper opening and a lower opening;
a hollow upper anchor of the plurality of bone anchors is configured to be received by the upper opening such that the hollow upper anchor extends into the upper vertebra; and
a hollow lower anchor of the plurality of bone anchors is configured to be received by the lower opening such that the hollow lower anchor extends into the lower vertebra;
the intervertebral body and the hollow upper anchor and the hollow lower anchor define the continuous bone cement flow path such that bone cement flows out of the hollow upper anchor into the upper vertebra, flows out of the hollow lower anchor into the lower vertebra, and forms a continuous cement structure extending through
the hollow upper anchor,
a portion of the intervertebral body between the hollow upper anchor and hollow lower anchor, and
the hollow lower anchor.
23 . The spinal implant system of claim 21 , wherein
the hollow upper anchor is configured to extend upwardly past a lower endplate of the upper vertebra when the intervertebral body contacts the lower endplate; and
the hollow lower anchor is configured to extend downwardly past an upper endplate of the lower vertebra when the intervertebral body contacts the lower endplate.
24 . The spinal implant system of claim 23 , wherein the hollow upper anchor is a first upper anchor, and the hollow lower anchor is a first lower anchor, the spinal implant system further including:
a second upper anchor configured to extend into the upper vertebra; and
a second lower anchor configured to extend into the lower vertebra,
wherein a continuous flow passageway extends through the first upper anchor and the second upper anchor, through the first lower anchor and the second lower anchor, and through a portion of an anchor-receiving bifurcated fixation hole of the intervertebral body, thereby rigidly locking the spinal implant system together after implantation in the subject.