Capsule cutter

A system and method for cutting tissue within a synovial cavity, which includes a cannula and a blade assembly. The cannula can define an internal lumen and a cutting port for accessing the internal lumen. The blade assembly can include a blade and a blade shall extending from the blade. The blade can be inserted into the internal lumen of the cannula through an access port of the cannula such that the blade is proximate the cutting port. The blade shaft can be operated to move the blade within the internal lumen relative to the cutting port between a retracted position and a deployed position. The blade can be received within the internal lumen in the retracted position and positioned, at least partially, within the cutting port in the deployed position.

TECHNICAL FIELD

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

BACKGROUND

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.

An arthroscopic procedure is frequently used to puncture the capsule tissue and provide an opening through which the blade can he 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 The cannula can then be reinserted into the synovial cavity and the blade withdrawn through the cannula.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.

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.

Overview

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 can be positioned in a radial wall of the cannula such that the cannula end is closed or 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 closed or 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.

In an example, a method for cutting tissue within a synovial cavity can include inserting a proximal end of a guide element into the synovial cavity. The method can also include inserting a proximal end of a cannula into the synovial cavity over the guide element. The cannula can define an internal lumen extending from the proximal end and a distal end and a cutting port for accessing the internal lumen. The method can also include inserting a blade positioned on a blade shaft into the internal lumen through an access port such that the blade is positioned adjacent the cutting portion. The method can also include manipulating the blade shaft to move the blade between a retracted position and a deployed position. The blade is received entirely within the internal lumen in the retracted position and at least a portion of the blade is positioned within the cutting port in the deployed position.

In an example, a system for cutting tissue within a synovial cavity can include a cannula and a blade assembly. The cannula can define an internal lumen extending from a proximal end and a distal end and can also define a cutting port for accessing the internal lumen. The blade assembly can include a blade and a blade shaft extending from the blade. The blade can be inserted into the internal lumen of the cannula through an access port in the distal end of the cannula such that the blade is proximate the cutting port. The blade shaft can be operated to move the blade within the internal lumen relative to the cutting port between a retracted position and a deployed position. The blade can be received within the internal lumen in the retracted position and positioned within the cutting port in the deployed position.

This overview is intended to provide an overview of subject matter of the present patent application. It is not intended to provide an exclusive or exhaustive explanation of the present subject matter. The detailed description is included to provide further information about the present patent application.

DETAILED DESCRIPTION

As depicted inFIG. 1, a capsule cutter10, according to an example of the present disclosure, can include a cannula assembly12and a blade assembly14having at least one blade16(referred to as “the blade16” or “each blade16” herein). The blade assembly14can be partially inserted into the cannula assembly12such that each blade16can be positioned within a cannula18of the cannula assembly. The blade assembly14can be actuated to move each blade16between a deployed position and a retracted position. In the deployed position, each blade16can be positioned within a cutting port20of the cannula18such that tissue can pass through the cutting port20for cutting with the corresponding blade16. In the retracted position, each blade16can be positioned away from the cutting port20to avoid cutting any tissue that enters the cutting port20. In at least one example, the blade assembly14can be configured such that each blade16can be initially positioned at the retracted position when the blade assembly14can be inserted into the cannula assembly12.

As depicted inFIGS. 1, 2B-2D, and 3, the cannula assembly12can include a cannula18having a proximal end22and a distal end24and defining at least one internal lumen22extending from the proximal end22to the distal end24. The cannula18can define at least one cutting port20for accessing the internal lumen22. In an example, the cutting port20can be positioned on a side wall of the cannula18between the proximal end22and the distal end24. In at least one example, the cutting port20can be positioned on a side wall of the cannula18proximal the proximal end22. The cannula18can include a guide port26positioned at the proximal end22and defining a proximal opening of the internal lumen22. In an example, the guide port26can be aligned with a longitudinal axis A-A defined by the internal lumen22of the cannula18. The cannula18can include an access port28proximal the distal end24. In an example, the access port28can be aligned with the longitudinal axis A-A.

As depicted inFIGS. 1, 2B-2D, and 3, the cannula assembly12can include a handle portion30positioned proximal the distal end24of the cannula assembly12. In an example, the handle portion30can define the access port28of the internal lumen22. The handle portion30can be gripped by an operator for positioning and reorienting the cannula18. In an example, the handle portion30can define an engagement feature32for attachment of the blade assembly14to the distal end24of the cannula assembly12.

As depicted inFIGS. 2C-2D, the blade assembly14can include the blade16, a base34, and a shaft36extending between the blade16and the base34. The blade16can be inserted into the internal lumen22through the access port28. In an example, the shaft36can be sized such that the blade16can be proximate the cutting port20when the blade16can be inserted through the access port28and the base34engages the cannula assembly12. In an example, the base34can include a releasable engagement feature38corresponding to the engagement feature32of the handle port30to releasably attach the blade assembly14to the cannula assembly12when the blade16can be inserted into the internal lumen22.

As depicted inFIGS. 2C-2D and 3, in an example, the shaft36can be slidably received within a channel38defined by the base34such that the shaft36can be slidable relative to the base34to move the blade16between a retracted position and a deployed position. As depicted inFIG. 2C, in the retracted position, the blade16can be moved away from the cutting port20such that the blade16can be primarily received within the internal lumen22. In this configuration, the cannula18protects the surrounding tissue from the blade16. As depicted inFIG. 2D, in the deployed position, the blade16can be moved into the cutting port20such that a portion of the blade16can be exposed through the cutting port20.

In an example, the shaft36can include a button40that can be manipulated to move the blade16between the retracted and deployed positions. In at least one example, the base34can include a spring42positioned within the channel38to bias the shaft36toward the retracted position. In this configuration, the blade assembly14can be attached to the cannula assembly12and the blade16inserted into the internal lumen22such that the blade16can be initially positioned in the retracted position. Upon manipulation by the operator, the blade16can be moved to the deployed position in order to position the blade16for cutting.

As depicted inFIGS. 2A-2D and 4, a method100for cutting tissue within a synovial cavity can comprise guide insertion and positioning102; cannula insertion over guide104; blade insertion into cannula106; blade deployment into cutting portion of the cannula108; and tissue cutting procedure110.

As depicted inFIG. 2A, the guide insertion and positioning102can include insertion of a K-wire112, switching stick or other guide element into the synovial cavity. The K-wire112can be inserted such that a proximal end114of the K-wire112can be positioned to a pre-determined depth within the synovial cavity. As illustrated inFIG. 2B, in an example, the pre-determined depth can be sufficient to such that the cutting port20is fully within the synovial cavity when the cannula18can be inserted into the synovial cavity along the K-wire112and such that the proximal end22of the cannula18approximate the proximal end114of the K-wire112.

As depicted inFIG. 2B, cannula insertion over guide104can include feeding a distal end116of the K-wire112into the guide port26of the cannula18and inserting the cannula18through the tissue along the K-wire112. In this configuration, the longitudinal axis A-A of the cannula18is generally parallel to the K-wire112as the cannula18is inserted through the tissue. In an example, the cannula18can be inserted such that the proximal end22of the cannula18approximate the proximal end114of the K-wire112.

As depicted inFIG. 2C, the blade insertion into cannula106can include insertion of the blade16and at least a portion of the blade shaft36of blade assembly14through the access port28in the handle assembly12. In an example, the releasable attachment feature38of the blade assembly14can be engaged to the attachment feature32to attach the blade assembly14to the handle assembly12. In an example, the blade shaft36can be sized such that the blade16can be initially positioned in the retracted position when the blade assembly14can be attached to the handle assembly12as depicted inFIG. 2C. In at least one example, the K-wire112can be removed from the tissue by drawing the K-wire112from the cannula18through the access port28prior to the insertion of the blade assembly14.

As depicted inFIG. 2D, the blade deployment108can include manipulating the button40of the blade shaft36to move the blade16axially such that the blade16can be moved into the deployed position and positioned within the cutting port20. In an example, the spring42can be compressed as the blade16is moved into the deployed position such that the spring42biases the blade16toward the retracted position when the blade16is released.

In the tissue cutting procedure110, the handle30can be manipulated to move the proximal end22of the cannula18and the blade16contained therein to position tissue within the cutting port20for cutting with the blade16. In an example, the button40can remain depressed while the tissue is being cut and released to retract the blade16when tissue cutting is completed.

VARIOUS NOTES & EXAMPLES

Example 1 can include subject matter, such as can include a method for cutting tissue within a synovial cavity, including inserting an inserted end of a guide element112into the synovial cavity. The method can include inserting a proximal end22of a cannula18into the synovial cavity over the guide element112. The cannula18defines an internal lumen22extending from the proximal end22and a distal end24and a cutting port20for accessing the internal lumen22. The method can include inserting a blade16positioned on a blade shaft36into the internal lumen22through an access port28such that the blade16can be positioned adjacent the cutting port20. The method can also include manipulating the blade shaft36to move the blade16between a retracted position and a deployed position. The blade16can be received entirely within the internal lumen22in the retracted position and at least a portion of the blade16can be positioned within the cutting port20in the deployed position.

Example 2 can include, or can optionally be combined with the subject matter of Example 1, to optionally include that the guide element112can comprise at least one of K-wire and a switching stick.

Example 3 can include, or can optionally be combined with the subject matter of one or any combination of Examples 1 or 2 to optionally include withdrawing the guide element112from the synovial cavity and the internal lumen22of the cannula18through the access port28in the cannula18.

Example 4 can include, or can optionally be combined with the subject matter of Example 3, to optionally include that the guide element112can be withdrawn from the internal lumen22of the cannula18prior to insertion of the blade16.

Example 5 can include, or can optionally be combined with the subject matter of one or any combination of any one of the preceding claims to optionally include that the cannula18defines a guide port26at the proximal end22of the cannula18. The guide element112can be inserted into the guide port26to align the cannula18with the guide element112as the cannula18can be inserted over the guide element112.

Example 6 can include, or can optionally be combined with the subject matter of one or any combination of any one of the preceding claims to optionally include that the cannula18further includes an engagement feature32.

Example 7 can include, or can optionally be combined with the subject matter of Example 6, to optionally include that the blade shaft36includes a base34including a releasable engagement feature38. The releasable engagement feature38can be engaged to the engagement feature32when the blade16is inserted into the internal lumen22to prevent removal of the blade16from the internal lumen22of the cannula18.

Example 8 can include, or can optionally be combined with the subject matter of Example 7, to optionally include manipulating the releasable engagement feature38to disengage the blade16from the cannula18; and drawing the blade16from the cannula18through the access port28.

Example 9 can include, or can optionally be combined with the subject matter of one or any combination of any one of the preceding claims to optionally include depressing a button attached to the blade shaft36to move the blade16into the deployed position.

Example 10 can include, or can optionally be combined with the subject matter of Example 9, to optionally include that the base34includes a spring42compressible as the blade16can be moved into the deployed position to bias the blade16toward the retracted position.

Example 11 can include, or can optionally be combined with the subject matter of one or any combination of Examples 9 or 10, to optionally include manipulating the cannula18to maneuver the proximal end22and cutting port20of the cannula18to draw tissue into the cutting port20.

Example 12 can include, or can optionally be combined with the subject matter of Example 11, to optionally include that the button40can be depressed as the tissue can be drawn into the cutting port20to cut the tissue with the blade16.

Example 13 can include, or can optionally be combined with the subject matter of Example 11, to optionally include that the button40can depressed after the tissue can be drawn into the cutting port20to move the blade16into the deployed position and cut tissue drawn into the cutting port20.

Example 14 can include subject matter, such as can include a system for cutting tissue within a synovial cavity that can include a cannula18and a blade assembly. The cannula18can define an internal lumen22extending from a proximal end22and a distal end24and defining a cutting port20for accessing the internal lumen22. The blade assembly can include a blade16and a blade shaft36extending from the blade16. The blade16can inserted into the internal lumen22of the cannula18through an access port28in the distal end24of the cannula18such that the blade16can be proximate the cutting port20. The blade shaft36can be operated to move the blade16within the internal lumen22relative to the cutting port20between a retracted position and a deployed position. The blade16can be received within the internal lumen22in the retracted position. The blade16can be positioned within the cutting port20in the deployed position.

Example 15 can include, or can optionally be combined with the subject matter of Example 14, to optionally include that the cutting port20can be positioned in a radial side wall of the cannula18.

Example 16 can include, or can optionally be combined with the subject matter of one or any combination of Examples 14 or 15 to optionally include that the proximal end22can be closed.

Example 17 can include, or can optionally be combined with the subject matter of one or any combination of Examples 14-16 to optionally include that the cannula18defines a guide port26in the proximal end22for receiving a guide element112.

Example 18 can include, or can optionally be combined with the subject matter of Example 17, to optionally include that the guide element112can comprise at least one of K-wire and a switching stick.

Example 19 can include, or can optionally be combined with the subject matter of one or any combination of Examples 17 or 18 to optionally include that the guide element112is removable through the access port28in the distal end24of the cannula18.

Example 20 can include, or can optionally be combined with the subject matter of one or any combination of Examples 17-19 to optionally include that the wide element112can be withdrawn from the internal lumen22of the cannula18prior to insertion of the blade16.

Example 21 can include, or can optionally be combined with the subject matter of one or any combination of Examples 17-20 to optionally include that the cannula18further includes an engagement feature32.

Example 22 can include, or can optionally be combined with the subject matter of Example 21, to optionally include a base34including a releasable engagement feature38. The releasable engagement feature38can be engaged to the engagement feature32when the blade16can be inserted into the internal lumen22to prevent removal of the blade16from the internal lumen22of the cannula18.

Example 23 can include, or can optionally be combined with the subject matter of one or any combination of Examples 17-22 to optionally include that the blade shaft36can further include a button operable to move the blade16into the deployed position via the blade shaft36.

Example 24 can include, or can optionally be combined with the subject matter of Example 23, to optionally include that the base34can further include a spring42compressible as the blade16can be moved into the deployed position to bias the blade16toward the retracted position.

Example 25 can include, or can optionally be combined with the subject matter of one or any combination of Examples 23 or 24 to optionally include manipulating the cannula18to maneuver the proximal end22and cutting port20of the cannula18to draw tissue into the cutting port20.

Example 26 can include, or can optionally be combined with the subject matter of Example 25, to optionally include that the button40can be depressed as the tissue is drawn into the cutting port20to cut the tissue with the blade16.

Example 27 can include, or can optionally be combined with the subject matter of Example 25, to optionally include that the button40can be depressed after the tissue is drawn into the cutting port20to move the blade16into the deployed position and cut tissue drawn into the cutting port20.

Each of these non-limiting examples can stand on its own, or can be combined in any permutation or combination with any one or more of the other examples.