阅读说明：本技术 通过韧带下空间递送治疗材料 (Delivering therapeutic materials through the sub-ligamentous space ) 是由 J·T·威尔塞 K·E·米勒 B·T·里夫斯 于 2019-10-21 设计创作，主要内容包括：提供了一种通过韧带下空间将治疗材料递送至椎间盘的方法。所述方法包含将工具定位在纵向韧带和椎间盘外表面的界面处,其中所述界面是所述韧带下空间。所述工具可以包含第一针和容纳在所述第一针内的第二针。所述第一针的插入端可以包含浅斜端。所述方法包含将所述第一针的所述插入端插入所述韧带下空间中。所述方法包含将所述第二针从所述第一针内展开到所述椎间盘的环和核中的至少一个中。所述方法包含将所述治疗材料递送至所述环和所述核中的至少一个。(A method of delivering a therapeutic material to an intervertebral disc through a sub-ligamentous space is provided. The method includes positioning a tool at an interface of a longitudinal ligament and an outer surface of an intervertebral disc, wherein the interface is the infraligament space. The tool may include a first needle and a second needle received within the first needle. The insertion end of the first needle may comprise a shallow beveled end. The method includes inserting the insertion end of the first needle into the sub-ligamentous space. The method includes deploying the second needle from within the first needle into at least one of the annulus and nucleus of the intervertebral disc. The method comprises delivering the therapeutic material to at least one of the ring and the core.)

1. A method of delivering a therapeutic material to an intervertebral disc through a sub-ligamentous space, the method comprising:

positioning a tool at an interface of a longitudinal ligament and an outer surface of an intervertebral disc, the interface being the sub-ligamentous space, the tool including a first needle and a second needle received within the first needle, and an insertion end of the first needle including a shallow beveled end;

inserting the insertion end of the first needle into the infraligament space;

deploying the second needle from within the first needle into at least one of the annulus and nucleus of the intervertebral disc; and

delivering the therapeutic material to at least one of the ring and the core.

2. The method of claim 1, wherein positioning the tool at the interface comprises guiding the tool through a region of an intervertebral foramen to the intervertebral disc, the region below a spinal nerve root and anterior to a spinal cord;

wherein the longitudinal ligament comprises a posterior longitudinal ligament; and is

Wherein inserting the first needle into the infraligament space comprises inserting the insertion end of the first needle below the posterior longitudinal ligament.

3. The method of claim 2, wherein inserting the first needle into the infraligament space comprises inserting the insertion end of the first needle up to half of a width of the posterior longitudinal ligament.

4. The method of claim 1, further comprising positioning an insertion angle of the second needle into the intervertebral disc by positioning an indicator coupled with the tool at 180 ° from an angle of curvature of the second needle.

5. The method of claim 1, further comprising positioning an opening of the insertion end of the first needle in a direction toward the ring.

6. The method of claim 1, wherein the first needle is an elongated rigid tube, and wherein the insertion end is formed at an angle in a range of 20 to 30 degrees.

7. The method of claim 1, wherein the second needle is an elongated flexible tube having a tactile tip, and wherein the second needle is formed of a shape memory alloy.

8. The method of claim 1, wherein the tool comprises a spring system configured to move the tool from a retracted position to an extended position,

wherein the spring system comprises at least a plate and a switch coupled to each other, the plate being positioned within the tool and coupled to the second pin, the switch being configured to move along an outer surface of the tool, and

wherein the spring plate is configured to deploy and retract the second needle from the first needle based on a direction of movement of the switch.

9. The method of claim 1, wherein the longitudinal ligament comprises an anterior longitudinal ligament; and is

Wherein inserting the first needle into the infraligament space comprises inserting the insertion end of the first needle below the anterior longitudinal ligament.

10. The method of claim 1, wherein positioning the tool at the interface of the longitudinal ligament and disc outer surface comprises positioning the tool parallel to the interface of the longitudinal ligament and disc outer surface.

11. The method of claim 1, wherein positioning the tool at the interface comprises guiding the tool through a Kambin triangle located near the intervertebral disc;

wherein the longitudinal ligament comprises a posterior longitudinal ligament; and is

Wherein inserting the first needle into the infraligament space comprises inserting the insertion end of the first needle below the posterior longitudinal ligament.

12. The method of claim 1, wherein deploying the second needle from within the first needle into at least one of the annulus and the nucleus of the intervertebral disc comprises deploying the second needle through a posterior or posterolateral portion of the intervertebral disc into at least one of the annulus and the nucleus of the intervertebral disc.

13. The method of claim 1, wherein deploying the second needle from within the first needle into at least one of the annulus and the nucleus of the intervertebral disc comprises deploying the second needle through an anterior or anterolateral portion of the intervertebral disc into at least one of the annulus and the nucleus of the intervertebral disc.

14. A method of delivering a therapeutic material to a posterolateral transforaminal foramen of an intervertebral disc, the method comprising:

positioning a tool at an interface of a posterior longitudinal ligament and an outer surface of an intervertebral disc, the interface being a sub-ligamentous space, the tool including a first needle and a second needle received within the first needle, and an insertion end of the first needle including a shallow beveled end;

inserting the insertion end of the first needle into the infraligament space;

deploying the second needle from within the first needle through a posterior or posterolateral portion of the disc into at least one of the annulus and nucleus of the disc; and

delivering the therapeutic material to at least one of the ring and the core.

15. The posterolateral transforaminal method of claim 14, wherein inserting the first needle into the infratough space comprises inserting the insertion end of the first needle up to half of a width of the posterior longitudinal ligament.

16. The posterolateral transforaminal method of claim 14, wherein the first needle is an elongated rigid tube, and wherein the insertion end is formed at an angle in the range of 20 to 30 degrees.

17. The posterolateral transforaminal method of claim 14, wherein positioning the tool at the interface of the longitudinal ligament and an outer surface of an intervertebral disc comprises positioning the tool parallel to the interface of the longitudinal ligament and an outer surface of an intervertebral disc.

18. A method of delivering a therapeutic material to an intervertebral disc, the method comprising:

positioning a tool at an interface of an anterior longitudinal ligament and an outer surface of an intervertebral disc, the interface being a sub-ligamentous space, the tool including a first needle and a second needle received within the first needle, and an insertion end of the first needle including a shallow beveled end;

inserting the insertion end of the first needle into the infraligament space;

deploying the second needle from within the first needle through an anterior or anterolateral portion of the disc into at least one of the annulus and nucleus of the disc; and

delivering the therapeutic material to at least one of the ring and the core.

19. The method of claim 18, wherein inserting the insertion end of the first needle into the sub-ligamentous space comprises inserting the insertion end of the first needle from a posterolateral side of the intervertebral disc.

20. The method of claim 18, wherein the insertion end of the first needle comprises a curved shape, and

wherein inserting the insertion end of the first needle into the sub-ligamentous space comprises inserting the insertion end of the first needle from an antero-lateral side of the intervertebral disc.

Background

As humans age, the human spine may show more and more signs of degeneration. Generally, early stages of spinal degeneration can be treated by conservative care, while later stages of spinal degeneration may involve structural changes of the spine that require fusion surgery. However, patients in the intermediate stages of spine degeneration often suffer from painful disc degeneration that does not respond to conservative care, which leaves patients with little choice to address their disc-borne pain.

In recent years, several regenerative therapies and treatments have been developed to aid in the biological and chemical recovery of disc degeneration. In these therapies and treatments, therapeutic materials can be delivered to the intervertebral disc to address discogenic pain and/or degeneration in the annulus fibrosus (and specifically, the nucleus pulposus of the intervertebral disc).

Delivery of the therapeutic material to the disc requires puncturing the disc by a needle in at least one of the outer annulus fibrosus or the vertebral endplates. However, the needle delivering the therapeutic material creates a pathway in the disc for the therapeutic material to exit the disc. In view of the significant peak in pressure within the intervertebral disc during the patient's daily activities, the therapeutic material may be expelled from the intervertebral disc at least partially through the needle-created pathway. In addition, the delivery of therapeutic materials through the bone through the endplates of the vertebral bodies may avoid damage to the outer annulus; however, this method of delivery may affect the endplates, which provide the main source of oxygen and nutrients for the almost avascular disc.

Disclosure of Invention

The present disclosure relates generally to devices and methods for treating damaged and/or diseased intervertebral discs. In particular, the present disclosure relates to devices and methods for delivering regenerative drugs and/or therapeutic materials (hereinafter "therapeutic materials") to an intervertebral disc through the sub-ligamentous space.

In one or more embodiments, the disclosed technology relates to a method of delivering a therapeutic material to an intervertebral disc through a sub-ligamentous space. In one or more embodiments, the method includes positioning a tool at an interface of a longitudinal ligament and an outer surface of an intervertebral disc, wherein the interface is the sub-ligament space. In one or more embodiments, the tool includes a first needle and a second needle received within the first needle, and the insertion end of the first needle includes a shallow bevel end. In one or more embodiments, the method includes inserting the insertion end of the first needle into the sub-ligamentous space. In one or more embodiments, the method includes deploying the second needle from within the first needle into at least one of the annulus and nucleus of the intervertebral disc. In one or more embodiments, the method comprises delivering the therapeutic material to at least one of the ring and the core.

In one or more embodiments, the disclosed technology relates to a method of delivering a therapeutic material to the posterolateral transforaminal space of an intervertebral disc. In one or more embodiments, the method comprises positioning a tool at an interface of a posterior longitudinal ligament and an outer surface of an intervertebral disc, wherein the interface is the infraligament space. In one or more embodiments, the tool includes a first needle and a second needle received within the first needle, and the insertion end of the first needle includes a shallow bevel end. In one or more embodiments, the method includes inserting the insertion end of the first needle into the sub-ligamentous space. In one or more embodiments, the method includes deploying the second needle from within the first needle through a posterior or posterolateral portion of the intervertebral disc into at least one of the annulus and nucleus of the intervertebral disc. In one or more embodiments, the method comprises delivering the therapeutic material to at least one of the ring and the core.

In one or more embodiments, the disclosed technology relates to a method of delivering a therapeutic material to an intervertebral disc. In one or more embodiments, the method includes positioning a tool at an interface of an anterior longitudinal ligament and an outer surface of an intervertebral disc, wherein the interface is the infraligament space. In one or more embodiments, the tool includes a first needle and a second needle received within the first needle, and the insertion end of the first needle includes a shallow bevel end. In one or more embodiments, the method includes inserting the insertion end of the first needle into the sub-ligamentous space. In one or more embodiments, the method includes deploying the second needle from within the first needle through an anterior or anterolateral portion of the disc into at least one of the annulus and nucleus of the disc. In one or more embodiments, the method comprises delivering the therapeutic material to at least one of the ring and the core.

The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular descriptions of exemplary embodiments of the invention as illustrated in the accompanying drawings wherein like reference numbers generally represent like parts of the disclosure.

Drawings

The following drawings illustrate specific embodiments of the present disclosure and therefore do not limit the scope of the disclosure. The drawings are not drawn to scale and are intended to be used in conjunction with the explanations in the following detailed description.

FIG. 1A shows a cross-sectional side view of an embodiment of a tool in a default position. FIG. 1B shows a cross-sectional side view of an embodiment of the tool in a deployed position.

Fig. 2 is a side view of a portion of a vertebra showing an embodiment of a posterolateral or transforaminal approach to an intervertebral disc from the posterior or posterolateral portion of the disc.

Fig. 3A is a partial cross-sectional view of a side view of a portion of a vertebra showing an embodiment of a posterolateral or transforaminal approach to an intervertebral disc. Fig. 3B is a posterior view of a portion of a vertebra showing an embodiment of a posterolateral or transforaminal approach to an intervertebral disc.

Fig. 4A is a partial cross-sectional view of a side view of a portion of a vertebra showing an embodiment of an approach to an intervertebral disc from the antero-lateral or anterior aspect of the disc through the anterior longitudinal ligament ("ALL approach"). Figure 4B is a front view of a portion of a vertebra showing an example of an ALL approach to an intervertebral disc.

FIG. 5A shows a cross-sectional side view of an embodiment of a tool in a default position. Fig. 5B shows a cross-sectional side view of an embodiment of the tool in a deployed position. Fig. 5C shows a cross-sectional top view of an embodiment of the tool in a deployed position.

Fig. 6A shows a cross-sectional side view of an embodiment of a tool in a default position. Fig. 6B shows a cross-sectional side view of an embodiment of the tool in a deployed position. FIG. 6C shows an isometric view of the concave side of the insertion end of the tool in a default position. Fig. 6D shows an isometric view of a second needle deployed from the concave side of the insertion end of the tool. Fig. 6E shows an isometric view of a second needle deployed from the concave side of the insertion end of the tool.

Detailed Description

The following discussion omits or only briefly describes certain conventional features that would be apparent to those skilled in the art in connection with treating damaged and/or diseased intervertebral discs. It should be noted that the various embodiments are described in detail with reference to the drawings, wherein like reference numerals represent like parts and assemblies of the present disclosure throughout the several views. References to various embodiments do not limit the scope of the claims appended hereto. Furthermore, any examples set forth in this specification are intended to be non-limiting and set forth only some of the many possible embodiments for the appended claims. Further, particular features described herein can be used in combination with other described features in each of the various possible combinations and permutations.

Unless otherwise explicitly defined herein, all terms are to be given their broadest possible interpretation, including meanings implied from the specification and meanings understood by those skilled in the art and/or defined in dictionaries, papers, etc. It must also be noted that, as used in the specification and the appended claims, the singular forms "a" and "an" and "the" include plural referents unless otherwise specified, and the term "comprises and/or" comprising "when used in this specification specifies the presence of stated features, elements, and/or components, but does not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof.

Embodiments of the present disclosure generally relate to devices and methods, for example, for treating damaged and/or diseased intervertebral discs. In particular, embodiments of the present disclosure relate to devices and methods for delivering regenerative drugs and/or therapeutic materials (hereinafter "therapeutic materials") to an intervertebral disc through a sub-ligamentous space. In one or more embodiments, the therapeutic material can comprise cells, such as stem cells, intervertebral disc cells, platelet rich plasma, blood, bone marrow concentrate, and other cell containing compositions; proteins, such as cytokines, growth and differentiation factors, and the like; pH standardized solutions such as buffer, saline, hyaluronic acid, and the like; and tissues such as micronized autologous and/or allogeneic discs, cartilage, or other therapeutic tissues. Embodiments of the apparatus and method are described below with reference to fig. 1A-5C.

Fig. 1A shows a cross-sectional side view of an embodiment of the tool 100 in a default position 114. Fig. 1B shows a cross-sectional side view of an embodiment of the tool 100 in the deployed position 116.

In one or more embodiments, the tool 100 can include a handle 102, a first needle 104, and a second needle 106. The handle 102 is connected to the first needle 104 and may be configured to receive at least a portion of the second needle 104. The handle 102 may be attached to a syringe or other device capable of storing and providing therapeutic material to the first needle 104 and/or the second needle 106.

The first needle 104 is configured to receive at least a portion of the second needle 106. The first needle 104 may be an elongated rigid tube having an insertion end 112 positioned on an end opposite the end connected to the handle 102. The insertion end 112 of the first needle 104 may include a sharp and shallow beveled end. In one or more instances, the angle of the beveled end of the first needle 104 may be formed to be 20 to 60 degrees, and more preferably 20 to 30 degrees. The first needle 104 may be formed of a radiopaque material, such as surgical grade stainless steel, or may be formed of a polymer or the like that may be radiopaque or radiolucent to varying degrees. In one or more embodiments, the first needle 104 can be used to access a sub-ligamentous space between the longitudinal ligament and the vertebral body.

The second needle 106 may be an elongated flexible tube configured to retract and deploy from within the first needle 104. The insertion end 120 of the second needle 106 may include a tactile tip. The gauge of the second needle 106 may be a variety of sizes that can be retracted and deployed from within the first needle 104, and more preferably, may be a minimum gauge that allows delivery of the selected therapeutic material. In one or more embodiments, the second needle 106 is configured to enter the intervertebral disc. The second needle 106 may be configured to deliver a therapeutic material to a location, such as a target intervertebral disc. The second needle 106 may be formed of a shape memory alloy such as nitinol and may be configured to bend. In one or more instances, the second needle 106 is configured to bend in a direction opposite the switch 108 connected to the handle 102. By bending the second needle 106 in a direction opposite to the switch 108, the user may use the switch 108 as a reference point to properly position and guide the second needle 106 to a location, such as a target disc. In one or more other cases, the second pin 106 can be configured to bend in another direction relative to the switch 108, such as a direction toward the switch 108, a direction perpendicular to the switch 108, a direction between base points relative to the switch 108 (e.g., northeast, southeast, southwest, or northwest), or at another angle relative to the position of the switch.

The tool 100 may be configured to be in a default position 114 (i.e., a retracted position) and an extended position 116. With the tool 100 in the default position 114, the second needle 106 is received within the first needle 104 such that the insertion end 120 of the second needle 106 does not extend beyond the opening of the insertion end 112 of the first needle 104. With the tool 100 in the deployed position 116, the second needle 106 is deployed from the insertion end 112 of the first needle 104. In the deployed position 116, the insertion end 120 of the second needle 106 may extend beyond the insertion end 112 of the first needle 104.

In one or more instances, the tool 100 may be moved between the default position 114 and the deployed position 116 by a spring system contained in the handle 102. The spring system may be positioned within the handle 102. The spring system may include a spring 110, a switch 108, and a spring plate 118. The spring 110 may be positioned around a portion of the second needle 106 positioned within the handle 102. The switch 108 may be positioned on an outer surface of the handle 102. The switch 108 may be configured to move along an outer surface of the handle 102. A spring plate 118 may be coupled to the switch 108 and positioned within the handle 102. The end 106a of the second pin 106 may be coupled to a spring plate 118.

In one or more instances, when the switch 108 is moved toward the proximal end 102a of the handle 102, the spring plate 118 moves simultaneously with the switch 108, thereby moving the second needle 106 out of the first needle 104 and into the deployed position 116. The switch 108 may move along a track formed in the handle 102. When switch 108 is moved toward proximal end 102a of handle 102, spring plate 118 compresses spring 110 toward proximal end 102a of handle 102.

The user may control the deployed length of second needle 106 based on the distance the user moves switch 108 along handle 102. For example, if the user moves the switch 108 a distance of 10% of the track, the second needle 106 may be deployed at a length that is 10% of the full deployed length of the second needle 106. In another example, if the user moves the switch 108 100% of the way along the track, the second needle 106 may be fully deployed. In one or more instances, the track may include a deployment length indicator to indicate the deployment distance of the second needle 106. For example, if the switch 108 is aligned with a 10% indicator on the track, the deployed length indicator may indicate that the second needle 106 may be deployed at a length that is 10% of the full deployed length of the second needle 106. Once in the deployed position 116, the switch 108 may be configured to lock in place on the handle 102 to maintain the tool 100 in the deployed position 116 and facilitate delivery of the treatment material. When the switch 108 is retracted, the spring may exert a force on the spring plate 118 to help return the tool to the default position 114. In one or more other cases, no spring may be included in the spring system.

In one or more other embodiments, the tool 100 may be a three-layer needle. The tri-layer needles may include an innermost needle, a middle needle, and an outermost needle. The outermost needle is configured to receive the middle needle and the innermost needle. The middle needle is configured to receive the innermost needle. The middle needle is configured to retract and deploy from the outermost needle. The innermost needle is configured to retract and deploy from the outermost needle and the middle needle. The insertion end of the outermost needle may include a blunt or tactile tip for reaching and/or "feeling" the lateral edge of the posterior longitudinal ligament 304 and/or the anterior longitudinal ligament 302. The end of the intermediate needle may include a sharp beveled end similar to the insertion end 112 that is configured to wedge under the posterior longitudinal ligament 304 and/or the anterior longitudinal ligament 302. The innermost needle may include one or more of the same features as the second needle 106.

Fig. 2 is a side view of a portion of a vertebra 200 illustrating an embodiment of a posterolateral transforaminal approach into an intervertebral disc 206 from the posterior or posterolateral portion of the intervertebral disc 206. Fig. 3A is a partial cross-sectional view of a side view of a portion of a vertebra 200 illustrating an embodiment of a posterolateral transforaminal approach to an intervertebral disc 206. Fig. 3B is a posterior view of a portion of the vertebra 200, illustrating an embodiment of a posterolateral transforaminal approach to the intervertebral disc 206. It should be noted that the portion of the vertebra 100 depicted in fig. 2-4B relates to the lumbar region of the spine; however, it should be noted that the embodiments discussed herein may relate to other portions of the spine, such as cervical and thoracic portions.

Vertebra 234a comprises vertebral body 202, which is positioned on an anterior side 208 of vertebra 234 a. The vertebral body 202 includes an endplate 218a positioned on an upper horizontal portion of the vertebral body 202 and an endplate 218c positioned on a lower horizontal portion of the vertebral body 202. Similarly, vertebra 234b comprises vertebral body 204, which is positioned on an anterior side 208 of vertebra 234 b. Vertebral body 204 includes endplate 218b positioned on an upper horizontal portion of vertebral body 202 and endplate 218d positioned on a lower horizontal portion of vertebral body 202 (shown in fig. 3A).

The vertebra 234a includes a posterior vertebral arch 236 positioned on the posterior side 210 of the vertebra 234 a. The posterior vertebral arch 236 includes the spinous process 228, lamina (lamina), left and right superior articular processes 220, left and right transverse processes 226, and left and right pedicles (pedicles), such as the left pedicles 230a and 230 b. It should be noted that the spinous process 228, the left superior articular process 220, the left transverse process 226, and the left pedicles 230a and 230B are shown in fig. 2-4B, and the discussion herein describes features of the left side of the spine; however, the discussion of features applies equally to the right side of the spine. The lamina extends from one end of the spinal canal 238 to the spinous process 228. A left pedicle 230a is attached to the vertebral body 202 and extends outward away from the vertebral body 202. The left superior articular process 220 is located between the lamina and the left pedicle 230 a. The posterior vertebral arch 236 and vertebral bodies 202 form a spinal canal 238 through which the spinal cord 214 passes. Similarly, vertebra 234b includes a posterior vertebral arch on the posterior side 210 of vertebra 234b, wherein the posterior vertebral arch includes one or more features similar to posterior vertebral arch 236.

The intervertebral foramen 224 may be a hollow arch of bone created by the pedicle 230a of vertebra 234a and the pedicle 230b of vertebra 234 b. The intervertebral foramen 224 creates a passageway for the spinal nerve root 216 to pass from the spinal cord 214 through the intervertebral foramen 224 and outward toward the corresponding part of the body, such as an organ, muscle, and/or sensory structure of the body. The Kambin triangle 222 is formed in the region of the intervertebral foramen 224 below the spinal nerve root 216, in front of the spinal cord 214, and has no vascular structure in an anatomically typical patient.

Intervertebral disc 206 is positioned within an intervertebral disc space 212 between two adjacent vertebral bodies, such as vertebral body 202 and vertebral body 204. The intradiscal space 212 is the region of the spinal column between two adjacent vertebral bodies. The intervertebral disc 206 connects two adjacent vertebral bodies and allows movement of a portion of the vertebra 200. The intervertebral disc 206 is composed of an annulus fibrosus 306 ("annulus 306") and a nucleus pulposus 308 ("nucleus 308"). The annulus 306 surrounds the nucleus 308 and connects to the vertebral endplates 218c and 218 b.

The posterior longitudinal ligament 304 extends along the posterior surface of each vertebra in the longitudinal direction of the spine. The width of the posterior longitudinal ligament 304 in the intradiscal space 212 is greater than the width of the posterior longitudinal ligament 304 in the area above the vertebral body (e.g., vertebral body 202). In one or more instances, the sub-ligamentous space 310 may be the area where the posterior longitudinal ligament 304 interfaces with the outer surface of the disc 206 and/or annulus 306. In one or more other instances, the sub-ligamentous space 310 of the posterior longitudinal ligament 304 may be a region located between an outer surface of a vertebral body (e.g., the vertebral body 202) and an inner surface of the posterior longitudinal ligament 304.

The anterior longitudinal ligament 302 extends along the anterior surfaces of the vertebrae in the longitudinal direction of the spinal column. The anterior longitudinal ligament 302 in the intradiscal space 212 has a width that is greater than the width of the anterior longitudinal ligament 302 in the area above the vertebral body (e.g., vertebral body 202). In one or more instances, the sub-ligamentous space 312 may be the area where the anterior longitudinal ligament 302 interfaces with the outer surface of the disc 206 and/or annulus 306. In one or more other instances, the sub-ligamentous space 312 of the anterior longitudinal ligament 302 can be a region located between an outer surface of a vertebral body and an inner surface of the anterior longitudinal ligament 304.

In one or more embodiments, the tool 100 can penetrate a target disc, such as disc 206, through the sub-ligamentous space 310. That is, the tool 100 may access the nucleus 308 or other internal structure of the intervertebral disc 206 by accessing the annulus 306 beneath the posterior longitudinal ligament 304 or the anterior longitudinal ligament 302.

In one or more instances, to initiate a posterolateral or transforaminal approach as shown in fig. 2-3B, the user may perform a light anesthesia at the injection site. The light anesthesia may allow the patient to provide feedback to the user to assist the first needle 104 of the tool 100 in safely passing under the spinal nerve 216 and under the lateral edge of the posterior longitudinal ligament 304 and into the infraligamentous space 310. For example, if the patient feels paresthesia or discomfort (which would indicate to the user that the tool 100 may have contacted a portion of the spinal nerve 216), the patient may notify the user.

In one or more embodiments, to access the posterior or posterolateral portion of the disc 206 via a posterolateral or transforaminal approach, a user inserts the tool 100 configured to be in the default position 114 into a portion of the patient's back at or near the target disc. Using image guidance, such as X-rays to view the injection site and the area surrounding the target disc, the user may guide the tool 100 through the inferior-anterior aspect of the intervertebral foramen 224 at the target disc level. That is, the user may guide tool 100 through Kambin triangle 222. In one or more embodiments, nerve monitoring sensors may be included on the insertion end 112 to detect whether the tool 100 contacts the spinal cord 214 and/or spinal nerve roots 216. The trajectory of the tool 100 may be maintained in front of the spinal cord 214. The user may guide the insertion end 112 of the first needle 104 from the posterolateral side of the intervertebral disc 206 to the sub-ligamentous space 310. The insertion end 112 may be parallel to the interface of the posterior longitudinal ligament 304 and the outer surface of the intervertebral disc 206. The user may guide the insertion end 112 of the first needle 104 in the sub-ligamentous space 310 (i.e., below the posterior longitudinal ligament 304) up to half the width of the posterior longitudinal ligament 304 while remaining in the sub-ligamentous space 310. For example, from the posterolateral side of the disc 206, the user may guide the insertion end 112 of the first needle 104 under the posterior longitudinal ligament 304 and toward the midline of the posterior longitudinal ligament 304. In one or more embodiments, the user can guide the insertion end 112 of the first needle 104 in the sub-ligamentous space 310, preferably without creating a needle track in the posterior longitudinal ligament 304. In one or more embodiments, the user can guide the insertion end 112 of the first needle 104 in the sub-ligamentous space 310 without moving an outside edge of the posterior longitudinal ligament 304 or by moving an outside edge of the posterior longitudinal ligament 304 with a retractor.

The user may optionally rotate the tool 100 to position the insertion angle of the second needle 106 into the intervertebral disc 206. In one or more instances, the user may rotate the tool 100 within the sub-ligamentous space 310 to position the angle of insertion of the second needle 106. The user may align the angle of insertion of the second needle 106 using the switch 108 as a guide. For example, for a user inserting the first needle 104 into the sub-ligamentous space 310 with the opening of the insertion end 112 facing the posterior longitudinal ligament 304, the user may rotate the tool 100 such that the switch 108 may be positioned at 180 ° from the angle of curvature of the second needle 106 in the deployed position 116. That is, the switch 108 may be positioned in a manner that indicates that the opening of the insertion end 112 of the first needle 104 faces in a direction toward the ring 306. In one or more other instances, indicia, such as an arrow or a point, may be positioned on the handle 102 in a manner that indicates that the opening of the insertion end 112 of the first needle 104 faces in a direction toward the ring 306.

After positioning the insertion angle of the second needle 106, the user may configure the tool 100 to the deployed position 116. To configure the tool 100 to the deployed position 116, a user may move the switch 108 along the outer surface of the handle 102, thereby deploying the second needle 106 from the first needle 104. The deployed second needle 106 may puncture at least a portion of the ring 306. In one or more embodiments, the insertion end 120 of the second needle 106 is configured to enter at least a portion of the nucleus 308 with the switch 108 moved to a fully deployed length of the second needle 106 (e.g., 100% of the distance that the switch 108 is moved within the handle 102) or near the fully deployed length (e.g., 65% to 99% of the distance that the switch 108 is moved within the handle 102). Having accessed at least a portion of core 308, the user may apply a therapeutic material to core 308. In one or more embodiments, the insertion end 120 of the second needle 106 is configured to be positioned within a portion of the loop 306 with the switch 108 partially moved into the deployed position 116 (e.g., the switch 108 moved within the handle 102a distance of 10% to 64% of the track), thereby allowing the user to annularly administer the therapeutic material. Once the insertion end 120 of the second needle 106 is positioned within the intervertebral disc 206, the therapeutic material is delivered to the intervertebral disc 206 through the second needle 106, for example, by being attached to a syringe plunger (such as plunger 626A in fig. 6A) by pressing down.

After completing delivery of the treatment material, the user may move the switch 108 to the default position 114 to retract the second needle 106 into the first needle 104. When the tool 100 is configured in the default position 114, the first needle 104 may be withdrawn from the patient. The user may withdraw first needle 104 along the same path anterior to spinal cord 214 and through Kambin triangle 222.

In one or more embodiments, by removing the first needle 104 from the sub-ligament space 310, the posterior longitudinal ligament 304 may seal or partially seal the needle track, thereby acting as an endogenous bandage to allow the needle track to heal and ensure that all or substantially all of the dose of therapeutic material remains within the intervertebral disc 206. For the case where the second needle 106 fully penetrates the annulus 306 and into the nucleus 308, the stiff collagenous structure of the posterior longitudinal ligament 304 may be used to occlude the full-thickness trans-annular needle track created by the second needle 106.

Fig. 4A is a partial cross-sectional view of a side view of a portion of the vertebra 200 illustrating an embodiment of an approach to the intervertebral disc 206 ("ALL approach") from the antero-lateral or anterior aspect of the intervertebral disc 206 through the anterior longitudinal ligament 302. Fig. 4B is an anterior view of a portion of vertebra 200, illustrating an example of an ALL approach to an intervertebral disc 206.

In one or more instances, to initiate an ALL approach as shown in FIGS. 4A-4B, the user may place a light anesthesia on the injection site. The light anesthesia may allow the patient to provide feedback to the user to assist the first needle 104 of the tool 100 in safely passing under the lateral edge of the anterior longitudinal ligament 302 and into the sub-ligamentous space 312. For example, if the patient feels paresthesia or discomfort (which would indicate to the user that the tool 100 may have contacted a portion of the spinal nerve 216), the patient may notify the user.

In one or more embodiments, to access the antero-lateral or anterior portion of the disc 206 via an ALL approach, a user inserts the tool 100 configured in the default position 114 into a portion of the patient's back at or near the target disc. Using image guidance, such as X-rays to view the injection site and the area surrounding the target disc, the user may guide the tool 100 (and in particular, the insertion end 112 of the first needle 104) from the posterolateral side of the disc 206 to the sub-ligamentous space 312. The insertion end 112 may be parallel to the interface of the anterior longitudinal ligament 302 and the outer surface of the intervertebral disc 206. The user may guide the insertion end 112 of the first needle 104 in the sub-ligamentous space 312 (i.e., below the anterior longitudinal ligament 302) up to half the width of the anterior longitudinal ligament 302 while remaining in the sub-ligamentous space 312. In one or more embodiments, the user can guide the insertion end 112 of the first needle 104 in the sub-ligamentous space 312, preferably without creating a needle track in the posterior longitudinal ligament 304. In one or more embodiments, the user can guide the insertion end 112 of the first needle 104 in the sub-ligamentous space 312 without moving the outer side edge of the anterior longitudinal ligament 302 or by moving the outer side edge of the anterior longitudinal ligament 302 with a retractor.

Similar to positioning the insertion angle of the second needle 106 in the posterior transforaminal approach, the user may optionally rotate the tool 100 to position the insertion angle of the second needle 106 into the intervertebral disc 206. In one or more instances, the user may rotate the tool 100 within the sub-ligamentous space 312 to position the angle of insertion of the second needle 106. The user may align the angle of insertion of the second needle 106 using the switch 108 as a guide. In one or more other instances, indicia, such as an arrow or a point, may be positioned on the handle 102 in a manner that indicates that the opening of the insertion end 112 of the first needle 104 faces in a direction toward the ring 306.

After positioning the insertion angle of the second needle 106, the user may configure the tool 100 to the deployed position 116. To configure the tool 100 to the deployed position 116, a user may move the switch 108 along the outer surface of the handle 102, thereby deploying the second needle 106 from the first needle 104. The deployed second needle 106 may puncture at least a portion of the ring 306. In one or more embodiments, the insertion end 120 of the second needle 106 is configured to enter at least a portion of the nucleus 308 with the switch 108 moved to a fully deployed length of the second needle 106 (e.g., 100% of the distance that the switch 108 is moved within the handle 102) or near the fully deployed length (e.g., 65% to 99% of the distance that the switch 108 is moved within the handle 102). Having accessed at least a portion of core 308, the user may apply a therapeutic material to core 308. In one or more embodiments, the insertion end 120 of the second needle 106 is configured to be positioned within a portion of the loop 306 with the switch 108 partially moved into the deployed position 116 (e.g., the switch 108 moved within the handle 102a distance of 10% to 64% of the track), thereby allowing the user to annularly administer the therapeutic material. Once the insertion end 120 of the second needle 106 is positioned within the intervertebral disc 206, the therapeutic material is delivered to the intervertebral disc 206 through the second needle 106, for example, by being attached to a syringe plunger (such as plunger 626A in fig. 6A) by pressing down.

After completing delivery of the treatment material, the user may move the switch 108 to the default position 114 to retract the second needle 106 into the first needle 104. When the tool 100 is configured in the default position 114, the first needle 104 may be withdrawn from the patient. The user may withdraw the first needle 104 along the same path that the first needle 106 entered the sub-ligamentous space 312. In one or more embodiments, by removing the first needle 104 from the sub-ligament space 312, the anterior longitudinal ligament 302 can seal or partially seal the needle track, thereby acting as an endogenous bandage to allow the needle track to heal and ensure that all or substantially all of the dose of therapeutic material remains within the disc 206. For the case where the second needle 106 fully penetrates the annulus 306 and into the nucleus 308, the stiff collagenous structure of the anterior longitudinal ligament 302 may be used to occlude the full-thickness trans-annular needle track created by the second needle 106.

In one or more other embodiments, to access the antero-lateral or anterior portion of the disc 206 via another ALL approach, the user may insert a bending tool into the anterior or antero-lateral portion of the patient's abdomen near the target disc level. The bending tool may include one or more of the same features as tool 100. However, the outer needle of the bending tool has a curved shape that is the inverse of the straight shape of the first needle 104. The curved shape of the outer needle may facilitate entry into the sub-ligamentous space 312 from the antero-lateral side of the disc 206. When the bending tool is inserted into the patient, the bending tool may be positioned such that the bending tool bends towards the intervertebral disc 206. Once the user guides the bending tool to the sub-ligament space 312, the user may guide the outer needle of the bending tool into the sub-ligament space 312 in an arc-shaped manner and/or a curved trajectory. In one or more embodiments, the inner needle of the bend tool may include one or more features in common with the second needle 106. The inner needle may be configured to bend away from the curvature of the outer needle, forming an "S" like shape when the bending tool is configured in the deployed position. When configured in the deployed position, the inner needle may enter the disc 206 from the antero-lateral or anterior portion of the disc 206. In the deployed position, the inner needle may puncture at least a portion of the ring 306. In one or more embodiments, the insertion end of the inner needle is configured to enter at least a portion of the nucleus 308 with the switch of the bending tool moved to the fully deployed length.

Fig. 5A shows a cross-sectional side view of an embodiment of a tool 500 in a default position 514. Fig. 5B shows a cross-sectional side view of an embodiment of the tool 500 in the deployed position 516. Fig. 5C shows a cross-sectional top view of an embodiment of the tool 500 in the deployed position 516.

In one or more embodiments, the tool 500 can include a handle 502, a first needle 504, and a second needle 506. The handle 502 is connected to the first needle 504 and may be configured to receive at least a portion of the second needle 504. The handle 502 may be attached to a syringe or other device capable of storing and providing therapeutic material to the first needle 504 and/or the second needle 506. In one or more embodiments, the tool 500 may be used in place of the tool 100 for a posterolateral or transforaminal approach as described herein to access the disc 206 from the posterior or posterolateral portion of the disc 206 or for an ALL approach to access the disc 206 from the antero-lateral or anterior portion of the disc 206. The discussion of fig. 5 herein discusses an exemplary embodiment of a posterolateral or transforaminal approach to the disc 206 from the posterior or posterolateral portion of the disc 206.

It should be noted that the handle 502, the second needle 506, and the spring system comprising the spring 510, the switch 508, and the spring plate 518 comprise one or more of the same features as described with respect to the handle 102, the second needle 106, and the spring system comprising the spring 110, the switch 108, and the spring plate 118. Therefore, the description of these features will not be repeated.

The first needle 504 is configured to receive at least a portion of the second needle 506. The first needle 504 may be an elongated rigid tube having an insertion end 512 positioned on an end opposite the end connected to the handle 502. The insertion end 512 of the first needle 504 may be a flat tissue lifter configured to separate the anterior longitudinal ligament 302 and/or the posterior longitudinal ligament 304 from the vertebral body. For example, a flat tissue elevator may be formed in a shape similar to the insertion end of a Penfield # 4 dissector. The insertion end 512 may facilitate blunt detachment of the anterior longitudinal ligament 302 and/or the posterior longitudinal ligament 304 from the annulus 306. The insertion end 512 may be formed in a concave shape. The first needle 504 may be formed of a radiopaque material, such as surgical grade stainless steel, or may be formed of a polymer or the like that may be radiopaque or radiolucent to varying degrees. In one or more embodiments, the first needle 504 can be used to access a sub-ligamentous space. In one or more embodiments, the second needle 506 can be configured to bend with the curvature of the insertion end 512. That is, the second needle 506 may curve with the concave shape of the insertion end 512 such that the path of the second needle 506 may follow a portion of the path of the concave end of the first needle 504.

The tool 500 may be configured to be in a default position 514 (i.e., a retracted position) and an extended position 516. With the tool 500 in the default position 514, the second needle 506 is received within the first needle 504 such that the insertion end 520 of the second needle 506 does not extend beyond the opening of the insertion end 512 of the first needle 504. With the tool 500 in the deployed position 516, the second needle 506 is deployed from the insertion end 512 of the first needle 504. In the deployed position 516, the insertion end 520 of the second needle 506 may extend beyond the insertion end 512 of the first needle 504.

In one or more embodiments, to access the posterior or posterolateral portion of the disc 206, a user inserts the tool 500 configured to be in the default position 514 into a portion of the patient's back at or near the target disc. Using image guidance, such as X-rays to view the injection site and the area surrounding the target disc, the user may guide the tool 500 through the inferior-anterior aspect of the intervertebral foramen 224 at the level of the target disc. That is, the user may guide tool 500 through Kambin triangle 222. The trajectory of the tool 500 may be maintained in front of the spinal cord 214. The user may guide the insertion end 512 of the first needle 104 to the lateral edge of the posterior longitudinal ligament 304 and separate the lateral edge of the posterior longitudinal ligament 304 from the intervertebral disc 206. The insertion end 512 of the first needle 504 may be configured to facilitate insertion between the anterior longitudinal ligament 302 and the annulus 306 of the intervertebral disc 206. The insertion end 512 of the first needle 504 may be inserted between the two types of tissue and, through a rocking motion, the two tissues may be separated and advanced into the sub-ligament space 312. In one or more instances, the user may guide the insertion end 512 of the first needle 104 from the posterolateral side of the intervertebral disc to the lateral edge of the posterior longitudinal ligament 304. The insertion end 512 may be parallel to the interface of the posterior longitudinal ligament 304 and the outer surface of the intervertebral disc 206. The insertion end 512 may be bent away from the annulus 306 when separating the lateral edge of the posterior longitudinal ligament 304 from the target disc 206.

After separating the lateral edge of the posterior longitudinal ligament 304 from the target intervertebral disc 206, the user may rotate the insertion end 512 to bend toward the annulus 306 to facilitate insertion of the second needle 506 into the sub-ligamentous space 310. The user may position the insertion angle of the second needle 506 in a similar manner as positioning the insertion angle of the second needle 106 and using the switch 108 as a guide. The user may configure the tool 500 to the deployed position 516. The user may deploy the second needle 506 in a manner similar to that described with respect to deploying the second needle 106. Similar to switch 108, a user may move switch 508 along handle 502 to control the penetration depth of second needle 506, which may range from full layer penetration of the treatment material applied to ring 306 within a shallow ring of treatment material and deposition of the treatment material into core 308.

After completing delivery of the therapeutic material, the user may move the switch 508 to the default position 514 to retract the second needle 506 into the first needle 504. When the tool 500 is configured to be in the default position 514, the first needle 504 may be withdrawn from the patient. The user may withdraw first needle 504 along the same path anterior to spinal cord 214 and through Kambin triangle 222. In one or more embodiments, by removing the first needle 504 from the sub-ligament space 310, the posterior longitudinal ligament 304 can seal or partially seal the needle track, thereby acting as an endogenous bandage to allow the needle track to heal and ensure that all or substantially all of the dose of therapeutic material remains within the disc 206. For the case where the second needle 506 penetrates the annulus 306 completely and into the nucleus 308, the stiff collagenous structure of the posterior longitudinal ligament 302 may be used to occlude the full-thickness trans-annular needle track created by the second needle 506.

Fig. 6A shows a cross-sectional side view of an embodiment of a tool 600 in a default position 614. Fig. 6B shows a cross-sectional side view of an embodiment of the tool 600 in the deployed position 616. Fig. 6C shows an isometric view of the concave side 620 of the insertion end 612 of the tool 600 in the default position 614. Fig. 6D shows an isometric view of the second needle 606 deployed from the concave side 620 of the insertion end 621 of the tool 600. Fig. 6E shows an isometric view of the deployment of the second needle 606 from the convex side 622 of the insertion end 612 of the tool 600.

In one or more embodiments, the tool 600 can include a handle 602, a first needle 604, and a second needle 606. The handle 602 is connected to a first needle 604 and may be configured to receive at least a portion of a second needle 606. The handle 602 may be attached to a syringe 626 or other device capable of storing and providing therapeutic material to the first needle 604 and/or the second needle 606. The plunger 626a may be depressed toward the syringe 626, thereby creating pressure within the syringe 626 and moving the treatment material out of the second needle 606. In one or more embodiments, the tool 600 may be used in place of the tool 100 for a posterolateral or transforaminal approach as described herein to access the disc 206 from the posterior or posterolateral portion of the disc 206 or for an ALL approach to access the disc 206 from the antero-lateral or anterior portion of the disc 206. The discussion of fig. 6 herein discusses an exemplary embodiment of an ALL approach to the disc 206 from the antero-lateral or anterior aspect of the disc 206.

It should be noted that handle 602, second pin 606, and the spring system comprising spring 610, switch 608, and spring plate 618 include one or more of the same features as described with respect to handle 102, second pin 106, and the spring system comprising spring 110, switch 108, and spring plate 118. Therefore, the description of these features will not be repeated.

The first needle 604 is configured to receive at least a portion of the second needle 606. The first needle 604 may be an elongated rigid tube having an insertion end 612 positioned on an end opposite the end connected to the handle 602. The insertion end 612 of the first needle 604 may be a flattened tissue lifter configured to separate the anterior longitudinal ligament 302 and/or the posterior longitudinal ligament 304 from the vertebral body. For example, a flat tissue elevator may be formed in a shape similar to the insertion end of a Penfield # 4 dissector. The insertion end 612 may facilitate blunt detachment of the anterior longitudinal ligament 302 and/or the posterior longitudinal ligament 304 from the annulus 306.

The tool 600 can include a cannula 624 positioned within at least a portion of the first needle 604 and/or at least a portion of the handle 602. The second needle 606 may reside within a cannula 624, thereby providing a track for the second needle 606 to deploy and retract from the first needle 604. The sleeve 624 may be configured to protrude into at least a portion of the concave side 620 or at least a portion of the convex side 622. In one or more instances, the distal end of the cannula 624 may be curved such that the second needle 606 is deployed on a curved path from the insertion end 612. In one or more other instances, the distal end of the cannula 624 may be straight such that the second needle 606 is deployed along a straight path from the insertion end 612. The second needle 606 may be flexible to accommodate bending within the cannula 624. In one or more instances, the insertion end 612 of the tool 600 can include a concave side 620 and a convex side 622 disposed on opposite sides of the insertion end 612 of the first needle 604 from one another. In one or more other instances, the insertion end 612 may include a flat surface instead of the concave surface of the concave side 620 and the convex surface of the convex side 622, which are disposed on opposite sides of the insertion end 612 from one another.

In one or more instances, the insertion end 612 of the first needle 604 may be configured such that the second needle 606 may be deployed from either the concave side 620 (as shown in fig. 6D) or the convex side 622 (as shown in fig. 6E). For the case where the second needle 606 is configured to deploy from the concave side 620, the distal end of the cannula 624 may be positioned toward the concave side 620, as shown in fig. 6C. For the case where the second needle 606 is configured to deploy from the convex side 622, the distal end of the cannula 624 may be positioned toward the convex side 622. In one or more instances, the tool 600 can be configured such that a user can selectively deploy the second needle 606 from the concave side 620 or from the convex side 622. For the case where the second needle 606 can be selectively deployed from either the concave side 620 or the convex side 622, the cannula 624 can be formed with two distal ends that branch off from the main body of the cannula 624, where the cannula 624 can be formed in a "Y" shape or a branch-like shape. One distal branch end of the cannula 624 may be positioned toward the concave side 620 and the other distal branch end of the cannula 624 may be positioned toward the convex side 622. The user may selectively deploy the second needle 606 to either the distal branch end of the cannula 624 on the concave side 620 or the distal branch end of the cannula 624 on the convex side 622.

The first needle 604 may be formed of a radiopaque material, such as surgical grade stainless steel, or may be formed of a polymer or the like that may be radiopaque or radiolucent to varying degrees. In one or more embodiments, the first needle 604 can be used to access a sub-ligamentous space. In one or more embodiments, the second needle 606 can be configured to bend with the curvature of the insertion end 612. That is, the second needle 606 may curve with the concave shape of the insertion end 612 such that the path of the second needle 606 may follow a portion of the path of the concave end of the first needle 604.

In one or more instances, to initiate an ALL approach as shown in FIGS. 6A-6B, the user may place light anesthesia at the injection site. The light anesthesia may allow the patient to provide feedback to the user to assist the first needle 604 of the tool 600 in safely passing under the lateral edge of the anterior longitudinal ligament 302 and into the sub-ligamentous space 312. For example, if the patient feels paresthesia or discomfort (which would indicate to the user that the tool 600 may have contacted a portion of the spinal nerve 216), the patient may notify the user.

In one or more embodiments, to access the antero-lateral or anterior portion of the disc 206 via an ALL approach, a user inserts the tool 600 configured in the default position 614 into a portion of the patient's back at or near the target disc. Using image guidance, such as X-rays to view the injection site and the area surrounding the target disc, the user may guide the tool 600 (and in particular, the insertion end 612 of the first needle 604) from the posterolateral side of the disc 206 to the sub-ligamentous space 312. The insertion end 612 of the first needle 604 may be configured to facilitate insertion between the anterior longitudinal ligament 302 and the annulus 306 of the intervertebral disc 206. The insertion end 612 of the first needle 604 may be inserted between the two types of tissue and, through a rocking motion, the two tissues may be separated and advanced into the sub-ligament space 312. The insertion end 612 may be parallel to the interface of the anterior longitudinal ligament 302 and the outer surface of the intervertebral disc 206. The user may guide the insertion end 612 of the first needle 604 in the sub-ligamentous space 312 (i.e., below the anterior longitudinal ligament 302) up to half the width of the anterior longitudinal ligament 302 while remaining in the sub-ligamentous space 312. In one or more embodiments, the user can guide the insertion end 612 of the first needle 604 in the sub-ligamentous space 312, preferably without creating a needle track in the posterior longitudinal ligament 304. In one or more embodiments, the user can guide the insertion end 612 of the first needle 604 in the sub-ligamentous space 312 without moving the outer side edge of the anterior longitudinal ligament 302 or by moving the outer side edge of the anterior longitudinal ligament 302 with a retractor.

Similar to using the tool 100 to position the insertion angle of the second needle 606 in the posterior transforaminal approach, the user may optionally rotate the tool 600 to position the insertion angle of the second needle 606 into the intervertebral disc 206. In one or more instances, the user may rotate the tool 600 within the sub-ligamentous space 312 to position the angle of insertion of the second needle 606. The user may align the angle of insertion of the second needle 606 using the switch 608 as a guide.

After positioning the insertion angle of the second needle 606, the user may configure the tool 600 to the deployed position 616. To configure the tool 600 to the deployed position 616, a user may move the switch 608 along an outer surface of the handle 602, thereby deploying the second needle 606 from the first needle 604. The deployed second needle 606 may puncture at least a portion of the ring 306. In one or more embodiments, the insertion end 621 of the second needle 606 is configured to enter at least a portion of the core 308 if the switch 608 is moved to a fully deployed length of the second needle 606 (e.g., the switch 608 is moved 100% of the way within the handle 602) or near the fully deployed length (e.g., the switch 608 is moved 65% to 99% of the way within the handle 602). Having accessed at least a portion of core 308, the user may apply a therapeutic material to core 308. In one or more embodiments, the insertion end 621 of the second needle 606 is configured to be positioned within a portion of the loop 306 with the switch 608 partially moved into the deployed position 616 (e.g., the switch 608 is moved within the handle 602 a distance of 10% to 64% of the track), thereby allowing the user to annularly administer the therapeutic material. Once the insertion end 621 of the second needle 606 is positioned within the intervertebral disc 206, the therapeutic material is delivered to the intervertebral disc 206 through the second needle 606.

After completing delivery of the therapeutic material, the user may move the switch 608 to the default position 614 to retract the second needle 606 into the first needle 604. When the tool 600 is configured in the default position 614, the first needle 604 may be withdrawn from the patient. The user may withdraw the first needle 604 along the same path that the first needle 606 entered the sub-ligamentous space 312. In one or more embodiments, by removing the first needle 604 from the sub-ligament space 312, the anterior longitudinal ligament 302 can seal or partially seal the needle track, thereby acting as an endogenous bandage to allow the needle track to heal and ensure that all or substantially all of the dose of therapeutic material remains within the intervertebral disc 206. For the case where the second needle 606 penetrates the annulus 306 completely and into the nucleus 308, the stiff collagenous structure of the anterior longitudinal ligament 302 may be used to occlude the full-thickness trans-annular needle track created by the second needle 606.