US20080082104A1 - Methods and apparatuses for facilitating percutaneous fusion - Google Patents

Abstract

A delivery mechanism comprising a dilator, catheter, lumen or the like is provided to allow a filler material to be injected to a gap in a partially fused intervertebral disc space to allow correction of the incomplete, partial, or deteriorated fusion.

Description

CLAIM OF PRIORITY UNDER 35 U.S.C. §§119, 120
• The present patent application claims priority to provisional patent application Ser. No. 60/820,558, filed Jul. 27, 2006, titled METHOD AND APPARATUSES FOR FACILITATING PERCUTANEOUS FUSION, the disclosure of which is incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
• None.
CROSS-REFERENCE TO RELATED APPLICATIONS
• None.
FIELD Of THE INVENTION
• The present invention relates to orthopedic fusion and, more particularly, to corrective measures useful to recover from incomplete or partial spinal fusion.
BACKGROUND OF THE INVENTION
• The vertebrae of the spine are arranged in a column with one vertebral body aligned on top of the next (at least when the spine is vertical). Between each vertebral body resides a spongy intervertebral disc that transmits forces between, adjacent vertebral bodies and provides a cushion between the adjacent bodies. The disc provides support for spine flexion, extension, and lateral motions.
• In some cases, intervertebral disc degeneration or other deformities (“diseased disc”) can cause back pain. Conventionally, surgeons treat diseased discs by surgically removing all or a portion of the diseased disc and inserting an implant in the space vacated by the diseased disc, which implant may be bone, PEEK material, or other biocompatible implants as are generally known in the art. The adjacent vertebral bodies are immobilized relative to one another and, eventually, the adjacent vertebral bodies grow into one solid piece of bone completing the fusion.
• For example, a convention method to fuse vertebral bodies includes piercing the intervertebral disc annulus. The surgeon removes all or a part of the disc nucleus. Next the surgeon would implant a fusion implant, such as a milled bone piece, or the like through the incision in the disc annulus.
• Typically, a fusion plate or the like immobilizes the adjacent vertebral bodies. Immobilizing the superior and inferior vertebral bodes with an implant prompts fusion between the superior and inferior bodies into one solid piece of bone.
• As can be appreciated, in some cases for whatever reason, the fusion does not properly occur. These incomplete or partial fusions require the surgery to be re-performed, which is traumatic and risky for the patient, and a drain on otherwise limited resources. Thus, it would be desirous to provide methods and apparatuses to correct incomplete or partial fusions.
SUMMARY OF THE INVENTION
• The technology of the present application provides a method, instrument, and system for facilitating correction of incomplete or partial bone fusion. The method comprises placing a guide having a distal end and a proximate end such that the distal end resides proximate the incomplete or partial bone fusion and the distal end resides external to a skin of the patient. The guide is used to guide a delivery tool to the surgical site. A reservoir having filler material is connected to the delivery tool such that filler material may be injected to the surgical site. The instrument comprises an apparatus for delivering filler material to a bone fusion site to facilitate correcting an incomplete or partial bone fusion. The filler material is contained in a reservoir that has an outlet and a plunger. The deliver mechanism places the reservoir and the surgical site in fluid communication such that depressing a plunger at the reservoir causes filler material to move through the delivery mechanism and be deposited in the surgical site. The system comprises a guide having a proximate end and a distal end, the proximate end adapted to be located external to a patient and the distal end adapted to be located at a surgical site. A delivery mechanism is slidably coupled to the guide and has a distal end adapted to access the surgical site and a proximal end. A reservoir comprising an outlet is coupled to the proximal end and a plunger opposite the proximal end such that the reservoir is in fluid communication with the surgical site through the delivery mechanism. A filler contained in the reservoir is adapted to be injected to the surgical site to promote bone fusion.
• The foregoing and other features, utilities and advantages of the invention will be apparent from the following more particular description of a preferred embodiment of the invention as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
• The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present invention, and together with the description, serve to explain the principles thereof. Like items in the drawings are referred to using the same numerical reference.
• FIG. 1 is a lateral elevation view of an incompletely or partially fused spinal segment with a delivery mechanism consistent with an embodiment of the present invention;
• FIG. 2 is a lateral elevation view ofFIG. 1 after a corrective implant is placed;
• FIG. 3 is a lateral elevation view ofFIG. 2 with the delivery mechanism removed;
• FIG. 4 is a flowchart illustrating a method of using the present delivery mechanism;
• FIG. 5 is a lateral elevation view of a spinal segment where the technology of the present application would be used; and
• FIG. 6 is a lateral elevation view of illustrating a portion of the technology of the present application.
DETAILED DESCRIPTION
• The present invention will now he described with reference to the figures. While the present invention is described specifically with respect to spinal fusion, one of ordinary skill in the art will recognize on reading the disclosure that the described minimally invasive procedure could be used to correct any incomplete or partial bone fusion.
• Referring first toFIG. 1, a lateral elevation view of aspinal segment100 is shown.Spinal segment100 includes a superiorvertebral body102 and an inferiorvertebral body104. Between superiorvertebral body102 and inferiorvertebral body104 is anintervertebral space106.Intervertebral space106 may have somebone growth108 as shown, or may not have any bone growth depending on the condition.Bone growth108 may include a portion of the original implant depending on the successfulness or lack thereof of the original fusion procedure. Aplate110 may couple superiorvertebral body102 and inferiorvertebral body104. The existence ofplate110 would largely depend on the original procedure and whetherplate110 was formed of resorbable materials or not.
• Also residing inintervertebral space106 is agap112. The size ofgap112 depends onbone growth108. While the present description contemplates thatgap112 forms due to incomplete or partial fusion, it is possible thatgap112 formed from deterioration of a complete fusion or cracking of a structure (seeFIG. 5). As shown inFIG. 1 in phantom by bone growth108a,bone growth108 may have completely traversedintervertebral space106 in some places, butbone growth108 may not have completely traversed theintervertebral disc space106 at all providing agap112 that traverses theintervertebral space106. While shown inFIG. 1 as having a distinct separation between bone growth areas, the incomplete, partial, or deteriorated fusion area may be a crack, fibrous joint, or hairline fracture500 (seeFIG. 5). Adelivery mechanism114 has adistal end116 and a proximal end118.Distal end116 resides ingap112. Proximal end118 ideally resides above the skin allowing for minimally invasive access togap112.Delivery mechanism114 is generally a pipe or tube and may be formed from a catheter, lumen, or the like. Ideally,delivery mechanism114 has as small an outer diameter D as possible.
• While not specifically shown, prior to inserting thedelivery mechanism114, the surgeon would access the non-union site, which is represented bygap112, using a trochar, guide wire, or the like as is common in the field. If a trochar (such as trochar612) is used, delivery mechanism is inserted via the trochar to thegap112. If a guide wire is used, thedelivery mechanism114 is placed over the guide wire. Once accessed, the opposing sides108band108cofbone growth108 may be roughed up, marred, struck, or the like to induce some bleeding. The bleeding in combination with a filler material described below would facilitate healing and further bone fusion. In many instances, once the bleeding is induced, the surgeon may want to irrigate the area and clear the area of any debris or the like formed from the roughing up of the site. In order to determine the site is properly prepared for the filler material, the surgeon may visually inspect the site using, for example, a fiber optic camera or the like. As can be appreciated, the instrument to induce bleeding has a longitudinal axis in line with the trochar, but may need to expand and contract as thegap112 expands and contracts. Also, the instrument may need to articulate or flex forgaps112 not in line with the longitudinal axis of the trochar. For example, referring toFIG. 6,bone segment600 is shown.Bone segment600 has opposing ends602 and604 withbone growth606 extending from each end. A variable shapedgap608 is shown separating thebone growths606 making the fusion incomplete. As can be seen,gap608 has afirst part608fpwith an axis610 substantially in line with anaxis612 of atrochar614.Gap608 further has asecond part608spwith anaxis616 substantially out of line withtrochar axis612. The various gaps may be misaligned both laterally, vertically, or a combination thereof. Thus, for marring instrument618 to function, it may have a pivot624 or to be flexible to align on multiple axes. Alternatively, or in combination with,trochar614 may be movable, flexible or pivotal to allow multiple axis alignments of marring instrument618. Also,first part608fphas a larger volume thansecond part608sp, thus marring instrument618 should have a sharp marringsurface620 that expands and contracts as necessary. Marringsurface620 is shown as a drum shape, but multiple shapes are possible. In this case,surface620 may induce bleeding via rotational movement, lateral movement, or a combination thereof. Bone segment could be any number of bone to bone surfaces a surgeon desires to fuse into a solid bone mass.
• Depending on the surgical technique,disc annulus120 may reside aboutintervertebral space106. In this case, which is shown,delivery mechanism114 is inserted to gap112 through an incision indisc annulus120. Whiledelivery mechanism114 is shown enteringgap112 from the posterior direction,delivery mechanism114 may enterintervertebral disc space106 from a surgeon selected direction to facilitate placingdistal end116 ingap112. Thus, ifgap112 resided on a lateral side ofintervertebral disc space106,delivery mechanism114 would be inserted through the lateral side.
• Oncedistal end116 ofdelivery mechanism114 is placed, afiller material202 is used to fillgap112 as shown inFIG. 2.FIG. 2 does not showplate110 for convenience.Filler material202 may be connected to proximal end118 ofdelivery mechanism114 using a syringe or the like. In particular,filler material202 is provided in a reservoir220 having an outlet222 connected to the proximal end118 ofdelivery mechanism114 and a plunger224 connected to reservoir220 opposite the outlet222. Plunger224 provide force to drivefiller material202 out outlet224 and throughdelivery mechanism114 to gap112 (sometimes referred to as the surgical site). The size ofdelivery mechanism114 is related, in part, to the viscosity offiller material202. Filler material202 a biocompatible adhesive, cement, polymer, resin, putty, biologics, or like. However, it is believedfiller material202 comprising a bone morphogenetic protein (“BMP”), other bone growth promoting biologics or pharmaceuticals, or the like as are generally know in the art would work well. Whilefiller material202 may be used alone, other bonegrowth promoting agents204 may be injected intogap112. For example,gap112 may be packed with bone chips as bonegrowth promoting agents204. Bone chips and BMPs may be used in isolation or in combination to facilitate bone growing into thegap112. While bonegrowth promoting agents204 andfiller material202 may be applied togap112 separately,filler material202 may include bonegrowth promoting agents204 as particulate held in a solution. Furthermore, other biologics and pharmaceuticals may be included in the filler material, such as, for example, antibiotic agents or the like.
• Referring now toFIG. 3,delivery mechanism114 is removed fromgap112. Ifannulus120 was pierced or cut (as shown by incision302), the incision302 may be closed using, for example, suture304, a scarring material306 (such as, for example, cotton or the like) or a combination thereof as necessary. Alternatively, anexpandable closure device308 may be inserted. However, the closure of incision302 is optional as incision302 should be relatively small in most cases.
• Referring now toFIG. 4, aflowchart400 describing the above procedure is provided. While shown in a particular order, one of ordinary skill in the art on reading the disclosure would now recognize alternative orders are possible. First, the surgeon identifies an incomplete, partial, or deteriorating fusion between a superior and an inferior vertebral body,step402. Next, the surgeon places a tool such as, a trochar, guide wire, dilator, catheter, lumen or the like through the skin of the patient until the tool abuts agap112 inintervertebral disc space106, step404. If disc annulus120 (or other membrane) is intact, the surgeon may need to make an incision in302 to access the non-union site, step406 (optional). The cutting instrument may be passed to the non-union site using the trochar, guide wire, dilator, catheter, lumen, or the like described above. Alternatively, the trochar may have a cutting edge to make the incision. Once the non-union site is accessed, the surgeon prepares the opposing surfaces or sides of the site for treatment,step408. Preparing the opposing side for treatment may involve, for example, aligning an instrument, such as instrument618 with the non-union site and scarring the opposing surfaces using rotational motion, lateral motion, other motion, or a combination thereof depending on the tool. Preparing the opposing sides for treatment also may include irrigating and suctioning the area to clear it of debris or excessive fluids. Once the area is prepared, the distal end of thedelivery mechanism114 is placed ingap112,step410. The proximal end of delivery mechanism remains outside the body of the patient and accessible by the surgeon.Delivery mechanism114 may be inserted through the trochar, a dilator, catheter, lumen, or the like or the guide tool above, such as, a dilator, catheter, turners, or the like may also function as thedelivery mechanism114. Optionally, bone growth promoting agents are packed intogap112, step412. Next, afiller material202 is injected to gap112 from a fluid supply (such as a syringe) that is connected to the proximal end ofdelivery mechanism114, step414. Filler material may comprise a fluid or a fluid containing particulate. It is envisioned thatfiller material202 may comprises BMPs, other bone growth promoting biologics or pharmaceuticals, or a combination thereof.
• Although described in the context of a spinal fusion, the methods and apparatuses described herein could be used in a number of fusion procedures. For example, the process could he used to facilitate postereolateral fusion, posterior fusions, odontoid fusions (failed fusions or chronic fractures), cracked crowns, other bones (especially long bones), or the like.
• Moreover, the above described methods an apparatuses could be used to facilitate a fusion procedure. For example, a surgeon may elect to fuse facet joints of a spinal segment to augment an anterior vertebral body fusion. In particular, a conventional anterior vertebral body fusion may be performed by a surgeon and, for a variety of reasons (including a fear of as incomplete or partial fusion of the segment), the surgeon may desire to augment the anterior fusion by fusing the facet joints or by performing another type of posterior fusion procedure. Currently, the posterior operation would require a second invasive incision of the patient along with dissection and resection of muscle and other tissue. The second procedure increases trauma and risk to the patient. However, using the above described procedure, the anterior fission could be augments by percutaneously accessing, for example, the facet joints, preparing the opposing surfaces, and applying the filler material.
• While the invention has been particularly shown and described with reference to embodiments thereof. It will be understood by those skilled in the art that various other changes in the form and details may be made without departing from the spirit and scope of the invention.

Claims (24)

1. A method of correct incomplete or partial bone fusions in patients, the method comprising the steps of:

placing a guide having a distal end and a proximate end such that the distal end resides proximate the incomplete or partial bone fusion and the distal end resides external to a skin of the patient;

guiding a distal end of a delivery tool to a surgical site using the guide;

providing a reservoir of filler material at a proximate end of the delivery tool, the filler material adapted to promote bone fusion;

injecting the filler material to the surgical site;

removing the delivery tool from the guide; and

removing the guide from the patient.

2. The method ofclaim 1, further comprising the steps of:

accessing the incomplete or partial bone fusion site with a surgical tool adapted to prepare the site for treatment;

treating the site to promote bone fusion; and

removing the surgical tool prior to guiding the distal end of the delivery tool to the surgical site.

3. The method ofclaim 2, wherein the step of treating the site to promote bone fusion comprises causing bleeding in the surgical site.

4. The method ofclaim 3, wherein the step of treating the site to promote bone fusion comprises scarring the surgical site.

5. The method ofclaim 1, further comprising the step of packing the surgical site with bone growth promoting agents.

6. The method ofclaim 1, wherein the packing the surgical site with bone growth promoting agents comprises inserting hone chips in the surgical site.

7. The method ofclaim 1, further comprising the steps of:

inserting a cutting tool through, the guide to make an incision in a disc annulus; and

incising the disc annulus,

8. The method ofclaim 7, further comprising the step of:

closing the incision after the delivery tool is removed from the guide.

9. The method ofclaim 8, wherein the step of closing the incision comprises suturing the disc annulus.

10. An apparatus for delivering filler material to a bone fusion site to facilitate correcting an incomplete or partial bone fusion, the apparatus comprising;

a reservoir adapted to contain filler material that promotes bone fusion, the reservoir having an outlet and a plunger opposite the outlet; and

a delivery mechanism having a proximal end and a distal end, the proximal end coupled to the outlet and in fluid communication with the reservoir, the distal end in fluid communication with the proximal end.

11. The apparatus ofclaim 10, wherein the filler material comprises at least one an agent to promote bone fusion selected from the group of agents consists of: an adhesive, a cement, a polymer, a resin, a putty, biologic agents, or an osteo-conductive material.

12. The apparatus ofclaim 10, wherein the filler material comprises at least a bone morphogentic protein.

13. The apparatus ofclaim 12, wherein the bone morphogentic protein comprises a bone morphogentic protein consisting of: BMP2, BMP7, or BMP 14.

14. The apparatus ofclaim 12, wherein the filler material comprises at least an osteo-inductive material.

15. The apparatus ofclaim 14, wherein the osteoinductive material comprises bone chips.

16. A system for correcting incomplete or partial bone fusions, comprising:

a guide having a proximate end and a distal end, the proximate end adapted to be located external to a patient and the distal end adapted to be located at a surgical site;

a delivery mechanism slidably coupled to the guide, the delivery mechanism having a distal end adapted to access the surgical site and a proximal end;

a reservoir comprising an outlet coupled to the proximal end and a plunger opposite the proximal end, the reservoir in fluid communication with the surgical site through the delivery mechanism; and

a filler, the filler contained in the reservoir and adapted to be injected to the surgical site, such that as the plunger is moved towards the outlet, the filler is injected to the surgical site.

17. The system ofclaim 16, further comprising:

a marring instrument, slidably coupled to the guide, the instrument having a distal end adapted to access the surgical site and mar the surgical site to induce bleeding.

18. The system ofclaim 16, wherein the filler comprises a bone fusion promoting agent selected from a group of hone fusion promoting agents consisting of: an adhesive, a cement, a polymer, a resin, a putty, biologic agents, or an osteo-conductive material.

19. The system ofclaim 16, wherein further comprising osteo-inductive material adapted to be injected to the surgical site.

20. The system ofclaim 17, wherein the marring instrument comprises a rotating marring surface.

21. The system ofclaim 17, wherein the marring instrument is flexible.

22. The system ofclaim 17, wherein the marring instrument comprises at least one pivot.

23. The system ofclaim 16, wherein the guide is a guide wire.

24. The system ofclaim 16, wherein the guide is a trochar.

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