Capsule cutter

Description

CLAIM OF PRIORITY

[0001] This patent application claims the benefit of priority to Gregory J. Denham U.S. Patent Application Serial Number 62 / 268,015, entitled "CAPSULE CUTTER," filed on December 16, 2015.TECHNICAL FIELD

[0002] This document pertains generally, but not by way of limitation, to a system for and related methods of piercing an articular capsule.BACKGROUND

[0003] Synovial joints have an articular capsule that surrounds the cartilage separating the bone ends and defines a synovial cavity that contains synovial fluid. The cartilage and other tissue within the synovial cavity can become damaged through overuse or injury requiring resection and removal of the damaged tissue. The damaged tissue can be removed by inserting a blade into the synovial cavity to resect the damaged tissue within the synovial cavity.

[0004] An arthroscopic procedure is frequently used to puncture the capsule tissue and provide an opening through which the blade can be inserted into the synovial cavity. The blade is typically set at an appropriate depth with an arthroscopic camera positioned within the synovial cavity. A switching stick or a Kirschner wire ("K-wire") is inserted through the exterior tissue and to the desired depth within the synovial cavity as visually confirmed by the arthroscopic camera. The switching stick can be used to guide a cannula inserted over the switching stick through the tissue wall into the synovial cavity. The switching stick can then be removed through the cannula and a blade can be inserted through the cannula, where the cannula protects the tissue wall of the synovial cavity from the blade as the blade is inserted within the synovial cavity. The cannula can be partially or entirely removed from the synovial cavity to unsheathe the cavity, which can be then maneuvered to resect the damaged tissue. The cannula can then be reinserted into the synovial cavity and the blade withdrawn through the cannula. After the blade is withdrawn, the switching stick can be reinserted into the cannula to guide removal of the cannula from the body.

[0005] A drawback of this approach is that the exposed blade can inadvertently damage healthy tissue by the fully exposed blade as the blade is maneuvered within the synovial cavity to cut the damaged tissue. Similarly, maneuvering of the cannula to unsheathe and sheathe the blade can cause unnecessary damage to the tissue wall. A related drawback is that the blade is often very thin to be passed through the cannula and can often break off during the resecting of damaged tissue. If the broken off portion of the blade cannot be retrieved through an arthroscopic procedure, a conventional invasive procedure that forms a larger opening the articular capsule could be required to retrieve the broken blade portion. Both the additional arthroscopic procedure and the conventional invasive procedure creates considerable risk for the patient and cause unnecessary damage to the healthy tissue.

[0006] EP2666422A1 discloses an obturator that provides access to a joint through a capsule surrounding the joint. A distal end of the obturator has a first distal location with a first width dimension and a second distal location with a second width dimension, wherein the second distal location is proximal to the first distal location and the second width dimension greater than the first width dimension. A retractable blade can extend from the obturator to be exposed between the first distal location and the second distal location.

[0007] US2011 / 046652A1 discloses instruments for use in minimally invasive carpal tunnel release including a cannula and a cutting member movable longitudinally within the cannula to advance a cutting blade of the cutting member along a longitudinal slot in the cannula to sever a transverse carpal ligament disposed over the slot. A dilating member is provided for creating a subligamentous space to accommodate the cannula and / or for removing adhered synovium from a lower surface of the ligament.

[0008] DE29521451U discloses a surgical instrument for endoscopic treatment that has viewing optics and a tubular member in which a cutting tool can be moved and tilted out beyond a diameter of the tubular member.OVERVIEW

[0009] The present inventors have recognized, among other things, that a problem to be solved can include safely delivering a blade to within a synovial cavity and minimizing risk of a broken or damaged blade. In an example, the present subject matter can provide a solution to this problem, such as by positioning the blade within an inner lumen of a cannula having a cutting port. The blade can be moved within the cannula between a deployed position in which the blade is positioned within the cutting port to permit cutting of tissue through the cutting port and a retracted position in which the blade is pulled away from the cutting port to prevent inadvertent cutting of tissue through the cutting port. The cutting port is positioned in a radial wall of the cannula such that the cannula end is partially closed thereby reducing the risk of a broken portion of the blade becoming lost within the synovial cavity. In at least one example, the partially closed end of the cannula can shield the surrounding tissue from the blade preventing cutting of tissue by the blade except through the cutting port.

[0010] In accordance with the present invention, there is provided a system as set out in claim 1. Optional features are set out in the dependent claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In the drawings, which are not necessarily drawn to scale, like numerals may describe similar components in different views. Like numerals having different letter suffixes may represent different instances of similar components. The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document. Figure 1 is a perspective view of a capsule cutter system according to the present invention. Figure 2A is a schematic view of insertion of a switching stick into a synovial cavity according to an example of the present disclosure. Figure 2B is a schematic view of insertion of a cannula assembly according to an example of the present disclosure over the switching stick depicted in Figure 2A. Figure 2C is a schematic view of insertion of a blade assembly according to an example of the present disclosure within the cannula assembly depicted in Figure 2B such that the blade is positioned in the retracted position. Figure 2D is a schematic view of actuation of the blade assembly to deploy a blade through a cutting port of the cannula assembly according to an example of the present disclosure. Figure 3 is a partial cross-sectional view of attachment of a blade assembly to a cannula assembly according to an example of the present disclosure. Figure 4 is a diagram of a method of transporting a blade safely into a synovial cavity and deploying the blade within the synovial cavity according to an example of the present disclosure. DETAILED DESCRIPTION

[0012] As depicted in FIG. 1, a capsule cutter 10, according to the present invention includes a cannula assembly 12 and a blade assembly 14 having at least one blade 16 (referred to as "the blade 16" or "each blade 16" herein). The blade assembly 14 can be partially inserted into the cannula assembly 12 such that each blade 16 can be positioned within a cannula 18 of the cannula assembly. The blade assembly 14 can be actuated to move each blade 16 between a deployed position and a retracted position. In the deployed position, each blade 16 can be positioned within a cutting port 20 of the cannula 18 such that tissue can pass through the cutting port 20 for cutting with the corresponding blade 16. In the retracted position, each blade 16 can be positioned away from the cutting port 20 to avoid cutting any tissue that enters the cutting port 20. In at least one example, the blade assembly 14 can be configured such that each blade 16 can be initially positioned at the retracted position when the blade assembly 14 can be inserted into the cannula assembly 12.

[0013] As depicted in FIGS. 1, 2B-2D, and 3, the cannula assembly 12 includes a cannula 18 having a distal end 22 and a proximal end 24 and defining at least one internal lumen 23 extending from the distal end 22 to the proximal end 24. The cannula 18 defines at least one cutting port 20 for accessing the internal lumen 23. In an example, the cutting port 20 can be positioned on a side wall of the cannula 18 between the distal end 22 and the proximal end 24. According to the present invention, the cutting port 20 is positioned on a side wall of the cannula 18 proximal the distal end 22. The cannula 18 includes a guide port 26 positioned at the distal end 22 and defining a proximal opening of the internal lumen 23. In an example, the guide port 26 can be aligned with a longitudinal axis A-A defined by the internal lumen 23 of the cannula 18. The cannula 18 includes an access port 28 proximal the proximal end 24. In an example, the access port 28 can be aligned with the longitudinal axis A-A.

[0014] As depicted in FIGS. 1, 2B-2D, and 3, the cannula assembly 12 can include a handle portion 30 positioned proximal the proximal end 24 of the cannula assembly 12. In an example, the handle portion 30 can define the access port 28 of the internal lumen 23. The handle portion 30 can be gripped by an operator for positioning and reorienting the cannula 18. In an example, the handle portion 30 can define an engagement feature 32 for attachment of the blade assembly 14 to the proximal end 24 of the cannula assembly 12.

[0015] As depicted in FIGS. 2C-2D, the blade assembly 14 includes the blade 16, a base 34, and a shaft 36 extending between the blade 16 and the base 34. The blade 16 is insertable into the internal lumen 23 through the access port 28. In an example, the shaft 36 can be sized such that the blade 16 can be proximate the cutting port 20 when the blade 16 can be inserted through the access port 28 and the base 34 engages the cannula assembly 12. In an example, the base 34 can include a releasable engagement feature 38 corresponding to the engagement feature 32 of the handle port 30 to releasably attach the blade assembly 14 to the cannula assembly 12 when the blade 16 can be inserted into the internal lumen 23.

[0016] As depicted in FIGS. 2C-2D and 3, in an example, the shaft 36 can be slidably received within a channel 38 defined by the base 34 such that the shaft 36 can be slidable relative to the base 34 to move the blade 16 between a retracted position and a deployed position. As depicted in FIG. 2C, in the retracted position, the blade 16 can be moved away from the cutting port 20 such that the blade 16 can be primarily received within the internal lumen 23. In this configuration, the cannula 18 protects the surrounding tissue from the blade 16. As depicted in FIG. 2D, in the deployed position, the blade 16 can be moved into the cutting port 20 such that a portion of the blade 16 can be exposed through the cutting port 20.

[0017] In an example, the shaft 36 can include a button 40 that can be manipulated to move the blade 16 between the retracted and deployed positions. In at least one example, the base 34 can include a spring 42 positioned within the channel 38 to bias the shaft 36 toward the retracted position. In this configuration, the blade assembly 14 can be attached to the cannula assembly 12 and the blade 16 inserted into the internal lumen 23 such that the blade 16 can be initially positioned in the retracted position. Upon manipulation by the operator, the blade 16 can be moved to the deployed position in order to position the blade 16 for cutting.

[0018] As depicted in FIGS. 2A-2D and 4, a method 100 for cutting tissue, not forming part of the claimed invention, within a synovial cavity can comprise guide insertion and positioning 102; cannula insertion over guide 104; blade insertion into cannula 106; blade deployment into cutting portion of the cannula 108; and tissue cutting procedure 110.

[0019] As depicted in FIG. 2A, the guide insertion and positioning 102 can include insertion of a K-wire 112, switching stick or other guide element into the synovial cavity. The K-wire 112 can be inserted such that a distal end 114 of the K-wire 112 can be positioned to a pre-determined depth within the synovial cavity. As illustrated in FIG. 2B, in an example, the pre-determined depth can be sufficient to such that the cutting port 20 is fully within the synovial cavity when the cannula 18 can be inserted into the synovial cavity along the K-wire 112 and such that the distal end 22 of the cannula 18 approximate the distal end 114 of the K-wire 112.

[0020] As depicted in FIG. 2B, cannula insertion over guide 104 can include feeding a proximal end 116 of the K-wire 112 into the guide port 26 of the cannula 18 and inserting the cannula 18 through the tissue along the K-wire 112. In this configuration, the longitudinal axis A-A of the cannula 18 is generally parallel to the K-wire 112 as the cannula 18 is inserted through the tissue. In an example, the cannula 18 can be inserted such that the distal end 22 of the cannula 18 approximate the distal end 114 of the K-wire 112.

[0021] As depicted in FIG. 2C, the blade insertion into cannula 106 can include insertion of the blade 16 and at least a portion of the blade shaft 36 of blade assembly 14 through the access port 28 in the handle assembly 12. In an example, the releasable attachment feature 38 of the blade assembly 14 can be engaged to the attachment feature 32 to attach the blade assembly 14 to the handle assembly 12. In an example, the blade shaft 36 can be sized such that the blade 16 can be initially positioned in the retracted position when the blade assembly 14 can be attached to the handle assembly 12 as depicted in FIG. 2C. In at least one example, the K-wire 112 can be removed from the tissue by drawing the K-wire 112 from the cannula 18 through the access port 28 prior to the insertion of the blade assembly 14.

[0022] As depicted in FIG. 2D, the blade deployment 108 can include manipulating the button 40 of the blade shaft 36 to move the blade 16 axially such that the blade 16 can be moved into the deployed position and positioned within the cutting port 20. In an example, the spring 42 can be compressed as the blade 16 is moved into the deployed position such that the spring 42 biases the blade 16 toward the retracted position when the blade 16 is released.

[0023] In the tissue cutting procedure 110, the handle 30 can be manipulated to move the distal end 22 of the cannula 18 and the blade 16 contained therein to position tissue within the cutting port 20 for cutting with the blade 16. In an example, the button 40 can remain depressed while the tissue is being cut and released to retract the blade 16 when tissue cutting is completed.

[0024] The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the present subject matter can be practiced. These embodiments are also referred to herein as "examples." Such examples can include elements in addition to those shown or described. However, the present inventors also contemplate examples in which only those elements shown or described are provided. Moreover, the present inventors also contemplate examples using any combination or permutation of those elements shown or described (or one or more aspects thereof), either with respect to a particular example (or one or more aspects thereof), or with respect to other examples (or one or more aspects thereof) shown or described herein.

[0025] In the event of inconsistent usages between this document and any documents so referenced, the usage in this document controls.

[0026] In this document, the terms "a" or "an" are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of "at least one" or "one or more." In this document, the term "or" is used to refer to a nonexclusive or, such that "A or B" includes "A but not B," "B but not A," and "A and B," unless otherwise indicated. In this document, the terms "including" and "in which" are used as the plain-English equivalents of the respective terms "comprising" and "wherein." Also, in the following claims, the terms "including" and "comprising" are open-ended, that is, a system, device, article, composition, formulation, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms "first," "second," and "third," etc. are used merely as labels, and are not intended to impose numerical requirements on their objects.

[0027] Method examples described herein can be machine or computer-implemented at least in part. Some examples can include a computer-readable medium or machine-readable medium encoded with instructions operable to configure an electronic device to perform methods as described in the above examples. An implementation of such methods can include code, such as microcode, assembly language code, a higher-level language code, or the like. Such code can include computer readable instructions for performing various methods. The code may form portions of computer program products. Further, in an example, the code can be tangibly stored on one or more volatile, non-transitory, or nonvolatile tangible computer-readable media, such as during execution or at other times. Examples of these tangible computer-readable media can include, but are not limited to, hard disks, removable magnetic disks, removable optical disks (e.g., compact disks and digital video disks), magnetic cassettes, memory cards or sticks, random access memories (RAMs), read only memories (ROMs), and the like.

[0028] The above description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more aspects thereof) may be used in combination with each other. Other embodiments can be used, such as by one of ordinary skill in the art upon reviewing the above description. The Abstract is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features may be grouped together to streamline the disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim.

[0029] The scope of the present subject matter should be determined with reference to the appended claims.

Claims

1. A system (10) for cutting tissue within a synovial cavity, comprising: a cannula (18) defining an internal lumen (23) extending from a proximal end (24) to a partially closed distal end (22) and defining a cutting port (20) positioned in a radial side wall of the cannula (18) proximal to the distal end (22), an access port (28) in the proximal end (24) of the cannula and a guide port (26) in the distal end (22) of the cannula (18), all for accessing the internal lumen (23); and a blade assembly (14) including a blade (16) and a blade shaft (36) extending from the blade, wherein the blade (16) is insertable into the internal lumen (23) of the cannula (18) through the access port (28) in the proximal end of the cannula (18) such that the blade is positioned adjacent the cutting port (20), wherein the blade shaft (36) is operable to move the blade (16) within the internal lumen (23) relative to the cutting port (20) between a retracted position and a deployed position, wherein the blade (16) is received within the internal lumen (23) in the retracted position and the blade is positioned within the cutting port in the deployed position such that tissue can pass through the cutting port (20) for cutting with the blade and wherein the system further comprises a guide element (112), the guide element (112) configured to be received in the guide port (26) in the distal end (22) of the cannula to align the cannula with the guide element (112).

2. The system of claim 1, wherein the guide element (112) comprises at least one of a K-wire and a switching stick.

3. The system of claim 1 or 2, wherein the guide element (112) is removable through the access port (28) in the proximal end of the cannula (18).

4. The system of any of claims 1 to 3 , wherein the internal lumen (23) of the cannula (18) is sized such that the guide element (112) is withdrawn from the internal lumen prior to insertion of the blade (16).

5. The system of any of the claims 1 to 4, wherein the cannula (18) further includes an engagement feature (32).

6. The system of claim 5, wherein the blade assembly further includes: a base (34) including a releasable engagement feature; wherein the releasable engagement feature is engagable to the engagement feature when the blade is inserted into the internal lumen to prevent removal of the blade from the internal lumen of the cannula.

7. The system of any of claims 1-6, wherein the blade shaft further comprises: a button (40) operable to move the blade into the deployed position via the blade shaft.

8. The system of claim 7, wherein the base further comprises: a spring (42) compressible as the blade is moved into the deployed position to bias the blade toward the retracted position.

9. The system of claims 7 or 8, wherein the proximal end of the cannula is configured to be manipulated to maneuver the distal end (22) and cutting port of the cannula to draw tissue into the cutting port.

10. The system of claim 9, wherein the button is configured to move the blade when depressed such that the blade cuts the tissue as the tissue is drawn into the cutting port.

11. The system of claim 9, wherein the button is configured to move the blade into the deployed position when depressed to cut tissue drawn into the cutting port.