Patent Publication Number: US-2022233232-A1

Title: Micro-invasive surgical device and methods of use

Description:
RELATED APPLICATION 
     The present application claims priority to International Patent Application No. PCT/US2020/012682, filed Jan. 8, 2020, and also claims priority to U.S. Provisional Patent Application No. 62/853,930, filed May 29, 2019, the entire contents of each of which are incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to a micro-invasive surgical device. More specifically, the present invention relates to a micro-invasive tissue cutting device having a first blade and a second blade, wherein the second blade is rotatable relative to the first blade. The present invention also provides methods of using the tissue cutting device, including a method of treating trigger finger. 
     BACKGROUND OF THE INVENTION 
     The first annular (“A1”) pulley is a small band of tissue on the palmar side of a person&#39;s hand. In some cases, the flexor tendon thickens and a nodule can get caught on the A1 pulley and cause irritation. The flexor tendon can then become locked in place when a person flexes his or her fingers. This condition is commonly referred to as “trigger finger.” To treat trigger finger, the A1 pulley is typically cut so as to release the tendon. For this purpose, certain devices are known that use a hook blade to perform such a procedure. However, a hook blade tends to slide off the tendon. Moreover, with such conventional devices, an additional, separate device is often required to introduce the hook blade into the person&#39;s skin. 
     As set forth in the present disclosure, it would be desirable to provide a tissue cutting device having a first blade and a second blade, wherein the second blade is rotatable relative to the first blade. In some cases, it would be desirable to provide such a device where the first blade facilitates introducing the tissue cutting device into and through a patient&#39;s skin. It would also be desirable to provide a device having a second blade that is protected by the first blade until the second blade is deployed for a cutting procedure. Additionally, it would be desirable to provide a tissue cutting device that is minimally invasive and that can be used to treat trigger finger. Still further, it would be desirable to provide a tissue cutting device having a lock for selectively controlling rotation of the second blade relative to the first blade. Further yet, it would be desirable to provide a tissue cutting device having one or more break points between the first blade and the second blade, wherein the one or more break points are configured to be disrupted. 
     SUMMARY OF THE INVENTION 
     In some embodiments, the invention provides a tissue cutting device comprising a handle, a first blade, and a second blade. The first blade and the second blade are coupled to the handle. The first blade is an exposed blade. The second blade is rotatable relative to the first blade such that the second blade is configured to rotate between a first position and a second position. The second blade is in a same plane as the first blade when the second blade is in the first position. The second blade is rotated into a different plane from the first blade as the second blade is rotated from the first position toward the second position. The second blade is an unexposed blade when in the first position and is an exposed blade when in the second position. 
     Certain other embodiments of the invention provide a tissue cutting device comprising a handle, a first blade, and a second blade. The first blade extends away from the handle, and the second blade is coupled to the handle. The second blade is rotatable relative to the first blade such that the second blade is configured to rotate between a first position and a second position. The tissue cutting device further includes a cover that is coupled to the handle. The second blade rotates from the first position toward the second position in response to rotation of the handle relative to the cover. 
     Certain other embodiments of the invention provide a tissue cutting device comprising a handle, a first blade, a second blade and one or more break points between the first blade and the second blade, the one or more break points being configured to be disrupted. When the one or more break points are intact, the first blade is connected to the second blade. When each of the one or more break points is disrupted, the first blade is separated from the second blade. In some cases, the one or more break points are configured to be disrupted by either rotational force or shear force. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top perspective view of a tissue cutting device in accordance with certain embodiments of the present disclosure, showing a handle coupled to a housing and a second blade in a first (inactive) position. 
         FIG. 2  is another top perspective view of the tissue cutting device of  FIG. 1 , showing the second blade in the first position. 
         FIG. 3  is a side perspective view of the tissue cutting device of  FIG. 1 , showing the first blade and the second blade lying in the same plane when the second blade is in the first position. 
         FIG. 4  is a top perspective of a tissue cutting device in accordance with certain embodiments of the present disclosure, showing a handle coupled to a housing and a second blade in a second (active) position. 
         FIG. 5  is another top perspective view of the tissue cutting device of  FIG. 4 , showing the second blade in the second position. 
         FIG. 6  is a side view of a tissue cutting device in accordance with certain embodiments of the present disclosure, showing a second blade in a second (active) position. 
         FIG. 7  is a schematic top perspective view of a tissue cutting device in accordance with certain embodiments of the present disclosure. 
         FIG. 8  is a schematic top perspective view of a tissue cutting device in accordance with certain embodiments of the present disclosure. 
         FIG. 9  is a top perspective view of a tissue cutting device in accordance with certain embodiments of the present disclosure. 
         FIG. 10  is an exploded view of a tissue cutting device showing a blade assembly separated from a handle. 
         FIG. 11  is a top perspective view of a tissue cutting device in accordance with certain embodiments of the present disclosure, showing a second blade in a first (inactive) position. 
         FIG. 12  is a top perspective view of the tissue cutting device of  FIG. 11 , with both an actuator and a lock of the tissue cutting device removed, and showing the second blade in a second (active) position. 
         FIG. 13  is an exploded view of the tissue cutting device of  FIG. 11 . 
         FIG. 14  is another exploded view of the tissue cutting device of  FIG. 11 . 
         FIG. 15  is a side perspective view of a lock, an actuator, and a projection of a tissue cutting device in accordance with certain embodiments of the present disclosure. 
         FIG. 16  is a top perspective view of a cover of a tissue cutting device in accordance with certain embodiments of the present disclosure. 
         FIG. 17A  is a top schematic view of an embodiment of a cover in accordance with certain embodiments of the present disclosure. 
         FIG. 17B  is a top schematic view of yet another embodiment of a cover, schematically showing rotation of the second blade between the first and second positions, with the second blade resting on the first blade when the second blade is in the first position. 
         FIG. 18  is a top perspective view of the tissue cutting device of  FIG. 11 , with a top end of the cover removed, and the second blade in the first position. 
         FIG. 19  is a top perspective view of the cutting device of  FIG. 11 , with a portion of the cover removed and showing the second blade in the first position. 
         FIG. 20  is a top perspective view of the cutting device of  FIG. 11 , with a portion of the handle removed, and showing the second blade in the second position. 
         FIG. 21  is a schematic top perspective view of a tissue cutting device having one or more break points in accordance with certain embodiments of the present disclosure. 
         FIG. 22A  is a schematic view of a tissue cutting device having one or more break points in accordance with certain embodiments of the present disclosure. 
         FIG. 22B  is a detailed view of the first and second blades shown in  FIG. 22A . 
         FIG. 23A  is a schematic view of a tissue cutting device having one or more break points in accordance with certain embodiments of the present disclosure. 
         FIG. 23B  is a detailed view of the first and second blades shown in  FIG. 23A . 
         FIG. 24A  is a schematic view of a tissue cutting device having one or more break points in accordance with certain embodiments of the present disclosure. 
         FIG. 24B  is a detailed view of the first and second blades shown in  FIG. 24A . 
         FIG. 25A  is a schematic view of a tissue cutting device having one or more break points in accordance with certain embodiments of the present disclosure. 
         FIG. 25B  is a detailed view of the first and second blades shown in  FIG. 25A . 
         FIG. 26A  is a schematic view of a tissue cutting device having one or more break points in accordance with certain embodiments of the present disclosure. 
         FIG. 26B  is a detailed view of the first and second blades shown in  FIG. 26A . 
         FIG. 27A  is a schematic view of a tissue cutting device having one or more break points in accordance with certain embodiments of the present disclosure. 
         FIG. 27B  is a detailed view of the first and second blades shown in  FIG. 27A . 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The following detailed description is to be read with reference to the drawings, in which like elements in different drawings have like reference numerals. The drawings, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of the invention. Skilled artisans will recognize that the examples provided herein have many useful alternatives that fall within the scope of the invention. 
     Referring to the drawings, and in particular,  FIGS. 1-10 , there is shown a tissue cutting device of the present disclosure generally represented by reference numeral  10 . The tissue cutting device  10  can be used to cut any desired soft tissue structure in the body (e.g., of a human or non-human mammal). Such soft tissue structure includes, but is not limited to, a ligament, fascia, or tendon. In certain preferred embodiments, the tissue cutting device  10  is used to cut an A1 pulley. 
     In some embodiments, the tissue cutting device  10  includes a handle  100 , a first blade  200 , and a second blade  300  that collectively define a blade assembly. The first blade  200  is coupled to the second blade  300  and both blades  200 ,  300  are coupled to the handle  100 . The first blade  200  is an exposed blade. As used in the present disclosure, an exposed blade refers to a blade that is not protected from contact with tissue. In contrast, an unexposed blade, as used in the present disclosure, refers to a blade that is protected from coming into contact with tissue by another structure of the device  10 . The handle  100 , the first blade  200 , and the second blade  300  can have any desired size suitable for performing a particular cutting procedure. In addition, the handle  100  can be formed of any desired medically acceptable material. 
     As shown in  FIGS. 1-5 and 10 , the tissue cutting device  10  can optionally include a housing  120 . In embodiments of this nature, the handle  100  is coupled to the housing  120  and extends outwardly (e.g., from a top end) of the housing  120 . The handle  100  can be either permanently or removably coupled to the housing  120 . Any conventional fastener can be used to couple the handle  100  to the housing  120 , including but not limited to, screws, glue, or the like.  FIGS. 1-5 and 10  show a non-limiting example of an embodiment where the handle  100  is screwed to the housing  120  via screws inserted into screw holes  121 ,  123 . 
     In certain cases, the handle  100  is positionable within the housing  120 . In other embodiments, the handle  100  is coupled to an exterior surface (e.g., top surface) of the housing  120  and does not extend into any portion of the housing  120 . However, a housing  120  is not required in all cases, and it is envisioned that the housing  120  can be omitted in certain embodiments. In any embodiment of the present disclosure that includes the housing  120 , it is preferred that the housing  120  has an ergonomic design configured to facilitate holding of the device  10 . 
     Where the housing  120  is provided, the housing  120  can comprise a single-piece structure. In other instances, the housing  120  comprises multiple sections ( FIG. 10 ), such as a first section  122  and a second section  124  that are coupled together. The sections  122 ,  124  of the housing  120  can be fixedly or removably coupled together. These sections  122 ,  124  can be coupled together in any conventional manner, such as by screws, snaps, glue or other adhesive. Other types of fasteners not explicitly recited herein can be used to couple together sections of the housing  120 , and such alternative fasteners will be readily apparent to skilled artisans. 
     In some embodiments, an interior surface  126  of the housing  120  has a recess  130  formed therein. As can be appreciated by referring to  FIG. 10 , the recess  130  is sized and shaped such that the recess  130  is configured to receive the handle  100  when the handle  100  is coupled to the housing  120 . Where the housing  120  includes the first section  122  and the second section  124 , the recess  130  is formed in at least one of the first section  122  and the second section  124  (and optionally, both sections) of the housing  120 . In certain other embodiments, the housing  120  does not include a recess  130 . 
     In preferred embodiments, the second blade  300  and the handle  100  are integral structures. In some cases, the handle  100 , the first blade  200 , and the second blade  300  are all integral structures. In still further embodiments, the entire tissue cutting device  10  can be a single integral structure so as to define a unibody construction. In such instances, for example, the entire device  10  can comprise a single piece of metal (e.g., surgical grade stainless steel), plastic, or any other suitable material. In addition, the tissue cutting device  10  can be manufactured by any conventional process. As non-limiting examples, the tissue cutting device  10  can be stamped or laser cut. 
     Advantageously, the second blade  300  is rotatable relative to the first blade  200  such that the second blade  300  is configured to rotate between a first (inactive) position  305  ( FIGS. 1-3 and 7-10 ) and a second (active) position  310  ( FIGS. 4-6 ). The second blade  300  is in a same plane as the first blade  200  when the second blade  300  is in the first position  305 . This is perhaps best illustrated in  FIG. 3 , which shows that the first blade  200  and the second blade  300  lie flat (i.e., parallel or substantially parallel) relative to each other when the second blade  300  is in the first position  305 . This arrangement of the tissue cutting device  10  provides a low-profile design that enables the tissue cutting device  10  to be inserted into tight spaces underneath a patient&#39;s skin, adjacent a desired tissue region. 
     The second blade  300  is rotated into a different plane from the first blade  200  as the second blade  300  is rotated from the first position  305  toward the second position  310 . As described in greater detail below, when the second blade  300  is in the first (inactive) position  305 , the second blade  300  is an unexposed blade that is protected (at least in part) by the first blade  200 . The second blade  300  can remain in the first position  305  until needed for a cutting procedure. Then, when it is desired to cut tissue using the second blade  300 , the second blade  300  is rotated into the second (active) position  310 , thereby becoming an exposed blade. 
     In certain embodiments, the tissue cutting device  10  is hingeless. In such embodiments, as shown in  FIGS. 1-10 , the material properties and design (including the shape of device  10 , as well as the thickness and flexibility of the second blade  300 ) allow the second blade  300  to intrinsically bend relative to the first blade  200 . The second blade  300  should be thin enough to allow the second blade  300  to bend to permit its rotation between the first  305  and second  310  positions. The second blade  300  is capable of being bent in a manner that is similar to bending of a paper clip (i.e., whereby twisting an inner portion of a metal paper clip allows the inner portion to be rotated and positioned outside of an outer portion of the paper clip). 
     In other embodiments, the tissue cutting device  10  includes one or more hinges. Any type of conventional mechanical hinge(s) can be used in tissue cutting device  10  to allow second blade  300  to rotate between its first  305  and second  310  positions. In other cases, the second blade  300  is provided with one or more virtual hinges, such as one or more seams that extend (e.g., longitudinally in series) along a longitudinal axis of the second blade  300 . In such instances, the one or more seams extend along the second blade  300  at one or more locations where the second blade  300  is materially coupled to the first blade  200  such that the one or more seams are provided at junction(s)  250  of the first blade  200  and the second blade  300 . The second blade  300  can be thinner in the region where the one or more seams are located so as to reduce resistance of the second blade  300  to bending. In this manner, the one or more seams facilitate folding and bending of the second blade  300  along the second blade&#39;s longitudinal axis for rotating the second blade  300  from its first position  305  toward its second position  310 . Thus, the one or more seams allow the second blade  300  to move from its first position  305  toward its second position  310  without separating the first blade  200  from the second blade  300 . 
     The second blade  300  rotates between the first position  305  and the second position  310  in response to rotation of the handle  100 . Thus, the second blade  300  and the handle  100  rotate together. The first blade  200  is configured to remain stationary or substantially stationary when the second blade  300  rotates from the first position  305  toward the second position  310 . The second blade  300  is configured to rotate along its longitudinal axis when the second blade  300  rotates between the first position  305  and the second position  310 . In preferred embodiments, the handle  100  is aligned (or substantially aligned) with the longitudinal axis of the second blade  300  such that the second blade  300  defines a linear extension of the handle  100 . 
     The second blade  300  can have any desired degree of rotation as needed to suit a particular cutting procedure. In some instances, the second blade  300  is configured to rotate in a range of between 0 to 180 degrees, including any degree therebetween. In other cases, the second blade  300  is configured to rotate in a range of between 0 and 90 degrees (including any degree therebetween). 
     The first blade  200  is configured to facilitate introduction of the tissue cutting device  10  through the dermis and into subcutaneous tissue of a patient. In this manner, the first blade  200  eliminates the need for the use of a separate, additional device to introduce the tissue cutting device  10  into the skin. Instead, in some embodiments, the tissue cutting device  10  has both the first blade  200  to introduce the device  10  into the skin, and the second blade  300  that can be unexposed and protected until needed to cut or release the tissue of interest. 
     The first blade  200  has a distal end  205 . In some cases, the outer surface of the first blade  200  includes one or more cutting surfaces. In other cases, the distal end  205  of the first blade  200  defines a tip not intended for cutting tissue. For example, in certain cases, the distal end  205  defines a blunt tip (e.g., a rounded, convex end) not intended for cutting tissue. In other cases, the distal end  205  defines a sharp-edged tip intended for cutting tissue. For example, in some cases, the distal end  205  defines a dissecting tip or a cutting tip. The configuration of the distal end  205  of the first blade  200  is not particularly limited. For instance, the distal end  205  of the first blade  200  can include a pointed tip ( FIG. 7 ), a curved edge ( FIG. 8  and  FIG. 21 ), a straight edge of uniform length, an angled surface that is longer on one side than on the other, or can have any other desired configuration. In addition, the one or more cutting surfaces of the first blade  200  (where provided) can extend along the entire outer surface of the first blade  200 , along a major length of the outer surface of the first blade  200  (i.e., along a length that is greater than 50% of a length of the outer surface), or along only a minor portion of the outer surface of the first blade  200 , such as only at the distal end  205 . 
     The second blade  300  also has at least one cutting surface  315 . In some embodiments, the cutting surface  315  of the second blade  300  is less sharp than the cutting surface and/or distal end  205  of the first blade  200 . In other cases, the cutting surface  315  of the second blade  300  is sharper than some (or all) of the outer surface of the first blade  200 . In still yet other cases, the cutting surface  315  of the second blade  300  has the same sharpness as the outer surface (or as the cutting surface) of the first blade  200 . 
     The configuration of the cutting surface  315  of the second blade  300  is also not limited. The cutting surface  315  can be a single cutting surface or one of many cutting surfaces. Also, the cutting surface  315  can be a curved surface, a straight surface (of uniform length), or an angled surface that is longer on one side than on the other side (e.g., a downward-angled cutting surface). In addition, the cutting surface  315  can face toward or away from the handle  100 , or can face toward either side of the tissue cutting device  10 . In some cases, the cutting surface  315  is provided on an interior surface of the second blade  300 . In other cases, the cutting surface  315  is provided on an outer surface of the second blade  300  (e.g., so as to provide a superficial cutting surface). In certain embodiments, the cutting surface  315  of the second blade  300  is a retrograde cutting surface configured to facilitate cutting of tissue when the second blade  300  is moved in a retrograde manner. In other cases, the cutting surface  315  of the second blade  300  is an antegrade cutting surface configured to facilitate cutting of tissue when the second blade  300  is moved in an antegrade manner. In yet other cases, the cutting surface  315  is both a retrograde and antegrade cutting surface. Skilled artisans will understand that the examples identified herein are not limiting, and that any type of cutting surface can be used as cutting surface  315 . Various cutting surfaces  315  are shown in the figures. Skilled artisans will appreciate that the cutting surfaces  315  shown in  FIGS. 22B, 23B, 24B, 25B, 26B, and 27B  can be provided in any embodiment of the present disclosure. 
     Although only one cutting surface  315  is shown in the drawings, the second blade  300  can have any desired number of cutting surfaces  315 , each having any desired configuration. In some cases, the second blade  300  is provided with a single cutting surface  315 . In other cases, the second blade  300  has more than one cutting surface  315  to allow the tissue cutting device  10  to achieve cuts in multiple directions. 
     In any embodiment of the present disclosure, the second blade  300  is optionally echogenic. In embodiments of this nature, the second blade  300  can have a flat superficial surface, etching, or an echogenic coating, with each of these features being designed to improve visualization of the second blade  300  under ultrasound. 
     The tissue cutting device  10  further includes a first arm  400  and a second arm  405 . The first arm  400  and the second arm  405  define opposite sides of the first blade  200 . The first arm  400  is coupled to and extends between the first blade  200  and a first side  105  of the handle  100 . In preferred embodiments, the first arm  400  is coupled directly to the handle  100 . The second arm  405  is coupled to the first blade  200  and extends from the first blade  200  toward a second side  110  of the handle  100 . However, unlike the first arm  400 , the second arm  405  does not contact any portion of the handle  100  (or the second blade  300 ). This space between the second arm  405  relative to both the handle  100  and the second blade  300  defines a gap  415 . As described in greater detail below, the second arm  405  is configured to stabilize the tissue cutting device  10  (particularly the first blade  200  and the first arm  400 ) when the second blade  300  is rotated from the first position  305  to the second position  310 . In particular, the gap  415  allows only a portion of the tissue cutting device to rotate (i.e., the handle  100  and the second blade  300 ), while a remainder of the device  10  is configured to remain stationary or substantially stationary. 
     When the second blade  300  is in the first position  305 , the cutting surface  315  of the second blade  300  is positioned between (e.g., directly between) the handle  100  and the first blade  200 . In more detail, the second blade  300  is located between the handle  100 , the first blade  200 , the first arm  400 , and the second arm  405  when the second blade  300  is in the first position  305 . Thus, the handle  100 , the first blade  200 , the first arm  400 , and the second arm  405  define an outer enclosure  410  surrounding the second blade  300  when the second blade  300  is in the first position  305 . This outer enclosure  410  protects the second blade  300  from contacting tissue when the second blade  300  is in the first position  305 . 
     The second blade  300  is configured to rotate outside of the outer enclosure  410  when the second blade  300  is rotated from the first position  305  toward the second position  310 . Rotation to the second position  310  allows the second blade  300  to be exposed for cutting tissue, since the second blade  300  is no longer protected by the outer enclosure  410 . In some cases, as shown in  FIGS. 1-10 , the outer enclosure  410  has a convex or substantially convex shape. However, alternative configurations for the outer enclosure  410  are also contemplated and within the scope of the present disclosure. 
     As the second blade  300  rotates from the first position  305  toward the second position  310 , the second arm  405  does not rotate (or at least remains stationary or substantially stationary). This is at least in part due to a greater surface area of the second arm  405  as compared to a surface area of the second blade  300 . In particular, the second blade  300  is thin enough to rotate when introduced subcutaneously into the skin near a tissue region of interest. The second arm  405 , on the other hand, is held down by the tissue or other structure to be cut and therefore is restrained from rotating when the second blade  300  rotates from the first position  305  toward the second position  310 . 
     In some cases, at least one tooth  420  is coupled to an interior surface  425  of at least one of the first arm  400  and the second arm  405 . In some cases, the at least one tooth  420  includes two or more teeth or a plurality of teeth. The at least one tooth  420  can be coupled to the only the first arm  400 , only the second arm  405 , or to both the first arm  400  and the second arm  405 . The at least one tooth  420  is perhaps best shown in  FIGS. 7 and 8 , where it is depicted as two teeth. The at least one tooth  420  is configured to embed into the undersurface of the structure to be cut (e.g., the A1 pulley) to ensure that the device  10  will not slide during use. The cutting surface  315  of the second blade  300  can extend outwardly toward the second arm  405  such that the at least one tooth  420  is positioned on an arm that is nearest the cutting surface  315 . 
     Another exemplary embodiment of a tissue cutting device  900  is shown in  FIG. 21 . Tissue cutting device  900  can optionally include any of the features previously described for  FIGS. 1-10 . This embodiment includes a first blade  200  and a second blade  300  and further includes one or more break points  450  between the first blade  200  and the second blade  300 . The one or more break points  450  are configured to be disrupted. The one or more break points  450  allow an operator to disrupt the one or more break points  450  and separate the first blade  200  from the second blade  300 . When the one or more break points  450  are intact, the second blade  300  is its first position  305 . When force is applied to each of the one or more break points  450  to separate the first blade  200  from the second blade  300 , the second blade  300  assumes its second position  310 . 
     Generally, the first blade  200  is coupled to the handle  100  via the one or more break points  450 , which are configured to break the first blade  200  away from the handle  100 . The second blade  300  is also coupled to the handle  100  but does not include any break points. In other words, the second blade  300  is configured to remain connected to the handle  100  and does not break away from the handle  100 . In some cases, the second blade  300  is integral to the handle  100 . The one or more break points  450  allow an operator to break away or separate the first blade  200  from the handle  100 , thus separating the first blade  200  from the second blade  300  and the handle  100 . In certain cases, the one or more break points  450  are configured to be disrupted when the second blade  300  is rotated from the first position  305  toward the second position  310 . 
     Referring to  FIG. 21 , certain embodiments include a first blade  200  that includes a distal end  205  and a proximal end  210 . The first blade  200  extends for a length “X” along its longitudinal axis from the distal end  205  to the proximal end  210 . The first blade  200  also includes a first arm  400  and a second arm  405 . The first arm  400  and the second arm  405  define opposite sides of the first blade  200 . Each the first arm  400  and the second arm  405  extend along the longitudinal axis between the distal end  205  and a proximal end  210 . 
     The first arm  400  is coupled to the handle  100  at the one or more break points  450 . The second arm  405  is not coupled to the handle  100 . Rather, the second arm  405  does not contact any portion of the handle  100 . A gap  415  is provided between the second arm  405  and the handle  100 . The one or more break points  450  can be provided anywhere along the first arm  400 . In certain cases, the one or more break points  450  are positioned on the first arm  400  such that the one or more break points  450  are adjacent to the proximal end  210 . 
     The one or more break points  450  are configured to break the first arm  400  from the handle  100  upon force. In other words, an operator applies force to the one or more break points  450  to disrupt them and therefore separate the first arm  400  (and thus the first blade  200 ) from the handle  100  (and thus the second blade  300 ). The one or more break points  450  can include any mechanism that allows force to break away the first arm  400  from the handle  100 . In certain cases, each of the one or more break points  450  is formed as a break-away seam. In other cases, each of the one or more break points  450  is formed as a break-away hinge. Such break-away seams or hinges can include snap perforations or frangible bridges that allow force to break away the first arm  400  from the handle  100 . 
     In certain embodiments, an operator uses rotational force to break away the first arm  400  from the handle  100 . For example, an operator rotates the handle  100  in either a clockwise or counterclockwise direction to disrupt the one or more break points  450 . In other embodiments, an operator uses shear force (e.g., a pushing or pulling force). Any number of break away mechanisms are contemplated. 
     Some embodiments also provide one or more flanges that extend outward from the first blade  200 . The one or more flanges are sized and shaped to accommodate an operator&#39;s fingers. An operator can grasp the one or more flanges to assist in manipulating the first blade  200 . In certain cases, the one or more flanges extend radially outward from the longitudinal axis of the first blade  200 . In some cases, the one or more flanges extend generally perpendicular from the longitudinal axis of the first blade  200 . In some cases, the one or more flanges are provided as a first flange and a second flange. The first flange and second flange can extend outward as a pair of wings, similar to flanges of a medical syringe. In other cases, the one or more flanges are provided as a single circular flange that surrounds the first blade  200 . A variety of different types of flanges are contemplated. 
     In the embodiment of  FIG. 21 , the first blade  200  includes a first flange  425  and a second flange  430 . The first flange  425  extends from the first arm  400  and the second flange  430  extends from the second arm  405 . Also, the first flange  425  extends radially outward from the first arm  400  and from the longitudinal axis of the first blade  200 , and the second flange  430  extends radially outward from the second arm  405  and from the longitudinal axis of the first blade  200 . In some cases, the first flange  425  and the second flange  430  can each extend generally perpendicular to the longitudinal axis, although this is not required. 
     As shown in  FIG. 21 , both the first flange  425  and the second flange  430  are positioned near a proximal end  210  of the first blade  200 . The first blade  200  is also provided with a length “X,” which is the length between the distal end  205  and the proximal end  210 . The length “X” is selected to be a maximum length of where the first blade  200  should be inserted into the body. The first flange  425  and the second flange  430  therefore prevent the first blade  200  from being inserted beyond the selected maximum length and therefore prevent it from being inserted too deeply into the body. The flanges  425 ,  430  also allow manipulation and stabilization of the whole device (including the handle  100 , first blade  200  and second blade  300 ) before separation of the first blade  200  from the handle  100 . 
     Once the first blade  200  is separated from the handle  100 , an operator can move the second blade  300  independently of the first blade  200 . In some cases, an operator can rotate the second blade  300  in a range of between 0 to 360 degrees. Any desired movement is possible since the second blade  300  is independent of the first blade  200 . An operator then uses the handle  100  to manipulate the second blade  300  to perform the desired cutting. Once cutting is completed, the operator pulls the handle  100  and thus the second blade  300  out of the body. The flanges  425 ,  430  also allow manipulation and stabilization of the first blade  200  after separation from the second blade  300 . For example, an operator can grasp the flanges  425 ,  430  with fingers and pull the first blade  200  out of the body. 
     One or more grip-enhancing features  460  can optionally be provided for any tissue cutting device of the present disclosure. The grip-enhancing feature(s)  460  are configured to improve the operator&#39;s ability to grip the tissue cutting device. In some cases, the one or more grip-enhancing features  460  are provided on the handle  100  and/or the flange(s)  425 ,  430 . In some cases, the one or more grip-enhancing features  460  comprise etching, texture, and/or marking indicia (e.g., logos, text, etc.). These examples, however, are by no means limiting, and skilled artisans will appreciate that any grip-enhancing features can be used. In the embodiments shown in  FIGS. 22A, 23A, 24A, 25A, 26A, and 27A , the one or more grip-enhancing features  460  comprise text (e.g., letters) on the handle  100 . 
     In certain embodiments, the first blade  200  comprises a lip  455 . When the second blade  200  is in the first position  305 , the lip  455  is configured to surround the cutting surface  315  of the second blade  300  such that the cutting surface  315  of the second blade  300  rests upon the lip  455 . In this manner, the lip  455  is configured to keep the cutting surface  315  of the second blade  300  from being deflected out of plane with respect to the first blade  200  while the second blade  300  is not intended to be used for cutting. Although the lip  455  is shown only in  FIG. 22B , such a lip can be provided in any embodiment of the present disclosure. 
     Although certain embodiments describing one or more break points  450  have been described, in some cases, the one or more break points  450  are omitted and replaced with one or more hinges. In such cases, the one or more hinges are provided in location(s) where the one or more break points  450  would otherwise be located. In such instances, the one or more hinges enable the second blade  300  to rotate relative to the first blade  200 , but does not allow the first blade  200  to be separated from the second blade  300 . In other words, the first blade  200  is configured to remain connected to the handle  100  and does not break away from the handle  100  (such that the first blade  200  and the second blade  300  also remain connected). In embodiments of this nature, any type of conventional mechanical hinge(s) can be used to allow second blade  300  to rotate between its first  305  and second  310  positions. In other cases, one or more virtual hinges, such as one or more seams, are provided. In such instances, the one or more virtual hinges (e.g., the one or more seams) extend along the first blade  200  at one or more locations where the first blade  200  is materially coupled to the handle  100 . In embodiments where one or more hinges are provided, the second blade  300  is able to rotate relative to the first blade  200  in a similar manner to the other hinge embodiments described herein (e.g. by rotating the handle  100 ). 
     The present disclosure also provides tissue cutting device  500 , shown in  FIGS. 11-20 . As with tissue cutting device  10 , tissue cutting device  500  can be used to cut any desired soft tissue structure in the body (e.g., of a human or non-human mammal). Such soft tissue structure includes but is not limited to, a ligament, fascia, or tendon. In certain embodiments, the tissue cutting device  500  is used to cut an A1 pulley. 
     Similar to cutting device  10 , cutting device  500  has a handle  600 , a first blade  700 , and a second blade  800 . The first blade  700  extends away from the handle  600 . The second blade  800  is coupled to and extends outwardly from the handle  600 . In some cases, the second blade  800  is screwed to the handle  600 . For example, as shown in  FIGS. 13 and 14 , the handle  600  and the second blade  800  can have screw holes  640 ,  803  formed therein for connecting the second blade  800  to the handle  600 . However, it will be appreciated that any conventional fastener, including but not limited to, screws, glue or other adhesive, can be used to couple the second blade  800  to the handle  600 . Furthermore, the handle  600  preferably has an ergonomic design configured to facilitate holding of the device  500 . 
     Similar to cutting device  10 , the handle  600 , the first blade  700 , and the second blade  800  of cutting device  500  can have any desired size suitable for performing a particular cutting procedure. In addition, the handle  600  can be formed of any desired medically acceptable material. 
     The first blade  700  is similar to the first blade  200  of device  10 . In particular, the first blade  700  is configured to facilitate introduction of the tissue cutting device  500  through the dermis and into subcutaneous tissue of a patient. In this manner, the first blade  700  eliminates the need for the use of a separate, additional device to introduce the tissue cutting device  500  into the skin. Instead, in some embodiments, the tissue cutting device  500  has both the first blade  700  to introduce the device  500  into the skin, and the second blade  800  that can be unexposed and protected until needed to cut or release the tissue of interest. 
     The first blade  700  has a shaft  702 . The shaft  702  includes a distal end  705  provided on an outer surface of the first blade  700 . In some cases, the distal end  705  of the first blade  700  includes one or more cutting surfaces. In other cases, the distal end  705  of the first blade  700  defines a blunt tip that is not intended for cutting tissue. The configuration of the distal end  705  of the first blade  700  is not particularly limited. For instance, the distal end  705  of the first blade  700  can include a pointed tip, a curved edge, a straight edge of uniform length, an angled surface that is longer on one side than on the other, or can have any other desired configuration. In addition, the one or more cutting surfaces of the first blade  700  can extend along the entire outer surface of the first blade  700 , along a major length of the outer surface (i.e., greater than 50% of a length of the outer surface) of the first blade  700 , or along only a minor portion of the outer surface of the first blade  700 , such as only at the distal end  705  of the outer surface of the first blade  700 . 
     The second blade  800  of device  500  is similar to the second blade  300  of device  10  and has a cutting surface  815 . In some embodiments, the cutting surface  815  of the second blade  800  is less sharp than the cutting surface and/or distal end  705  of the first blade  700 . In other cases, the cutting surface  815  of the second blade  800  is sharper than some (or all) of outer surface of the first blade  700 . In still yet other cases, the cutting surface  815  of the second blade  800  has the same sharpness as the outer surface (or as the cutting surface) of the first blade  700 . 
     The configuration of the cutting surface  815  of the second blade  800  is also not limited. As shown, the cutting surface  815  can be a curved surface, a straight surface (or uniform length), an angled surface that is longer on one side than on the other side (e.g., a downward-angled cutting surface). In addition, the cutting surface  815  can face toward or away from the handle  600 , or can face toward either side of the tissue cutting device  500 . In some cases, the cutting surface  815  is provided on an interior surface of the second blade  800 . In other cases, the cutting surface  815  is provided on an outer surface of the second blade  800  (e.g., so as to provide a superficial cutting surface). In certain embodiments, the cutting surface  815  of the second blade  800  is a retrograde cutting surface configured to facilitate cutting of tissue when the second blade  800  is moved in a retrograde manner. In other cases, the cutting surface  815  of the second blade  800  is an antegrade cutting surface configured to facilitate cutting of tissue when the second blade  800  is moved in an antegrade manner. Skilled artisans will understand that the examples identified herein are not limiting, and that any type of cutting surface can be used as cutting surface  815 . 
     Although only one cutting surface  815  is shown in the drawings, the second blade  800  can have any desired number of cutting surfaces  815 , each having any desired configuration. In some cases, the second blade  800  is provided with a single cutting surface  815 . In other cases, the second blade  800  has more than one cutting surface  815  to allow the tissue cutting device  500  to achieve cuts in multiple directions. 
     The second blade  800  is rotatable relative to the first blade  700  such that the second blade  800  is configured to rotate between a first (inactive) position  805  ( FIGS. 11, 18, and 19 ) and a second (active) position  810  ( FIGS. 12 and 20 ). The second blade  800  is in a same plane as the first blade  700  when the second blade  800  is in the first position  805 . The second blade  800  is in a different plane from the first blade  700  when the second blade  800  is rotated from the first position  805  toward the second position  810 . This can be appreciated by comparing  FIG. 11  with  FIG. 12 . 
       FIGS. 11, 18 and 19  show that both the first blade  700  and the second blade  800  lie flat (i.e., parallel or substantially parallel) relative to each other when the second blade  800  is in the first position  805 . This arrangement of the tissue cutting device  500  provides a low-profile design that enables the tissue cutting device  500  to be inserted into tight spaces underneath a patient&#39;s skin, adjacent a desired tissue region. 
     The second blade  800  is rotated into a different plane from the first blade  700  as the second blade  800  is rotated from the first position  805  toward the second position  810 . As described in greater detail below, when the second blade  800  is in the first (inactive) position  805 , the second blade  800  is an unexposed blade that is protected from contacting tissue. The second blade  800  can remain in the first position  805  until needed for a cutting procedure. Then, when it is desired to cut tissue using the second blade  800 , the second blade  800  is rotated into the second (active) position  810 , thereby becoming an exposed blade. 
     In preferred embodiments, the first blade  700  is in contact (e.g., direct physical contact) with the second blade  800  when the second blade  800  is in the first position  805 . This configuration is shown schematically in  FIG. 17B . In some cases, the shaft  702  of the first blade  700  has a recessed area (not shown) in an upper surface  704  thereof configured to receive the shaft  802  of the second blade  800 . This arrangement allows the second blade  800  to be recessed into the first blade  700 . The depth of the recessed area in the shaft  702  of the first blade  700  is variable such that the extent to which the first blade  700  is recessed into the second blade  800  is also variable. The recessed area in the shaft  702  of the first blade  700  can be an imprint formed in any conventional manner, e.g., by stamping. In certain embodiments, the first blade  700  is entirely recessed within the second blade  800  when the second blade  800  is in the first position  805 . In such cases, when the second blade  800  is rotated from the first position  805  toward the second position  810 , at least a portion of the second blade  800  rotates out of the recessed area of the first blade  700 . In other cases, the shaft  702  of the first blade  700  does not include a recessed area. Instead, the second blade  800  is positioned so as to lie on top of, and directly contact, the upper surface  704  of the first blade  700 . 
     In still yet other cases, the first blade  700  and the second blade  800  are not in direct contact when the second blade  800  is in the first position  805  such that a gap is formed between the first  700  and second  800  blades. However, since tissue may become trapped within the gap, it is preferable that the gap (where present) be as small as possible. 
     In certain embodiments, the tissue cutting device  500  is hingeless. In such embodiments, as shown in  FIGS. 11-20 , the material properties and design (including the shape of device  500 , as well as the thickness and flexibility of the second blade  800 ) allow the second blade  800  to intrinsically bend relative to the first blade  700 . This optional hingeless feature of device  500  is similar to certain hingeless embodiments of device  10 . 
     In other embodiments, the tissue cutting device  500  includes one or more hinges. Any type of conventional mechanical hinge(s) can be used in tissue cutting device  500  to allow second blade  800  to rotate between its first  805  and second  810  positions. In other cases, the second blade  800  is provided with one or more virtual hinges, such as one or more seams that extend (e.g., longitudinally in series) along a longitudinal axis of the second blade  800 . In such instances, the one or more seams extend along the second blade  800  at location(s) where the second blade  800  is materially coupled to the first blade  200  such that the one or more seams are provided at junction(s) of the first blade  700  and the second blade  800 . The second blade  800  can be thinner in the region where the one or more seams are located so as to reduce resistance of the second blade  800  to bending. In this manner, the one or more seams facilitate folding and bending of the second blade  800  along the second blade&#39;s longitudinal axis for rotating the second blade  800  from its first position  805  toward its second position  810 . 
     The second blade  800  rotates between the first position  805  and the second position  810  in response to rotation of the handle  600 . Thus, the second blade  800  and the handle  600  rotate together. The first blade  700  is configured to remain stationary or substantially stationary when the second blade  800  rotates from the first position  805  toward the second position  810 . The second blade  800  is configured to rotate along its longitudinal axis when the second blade  800  rotates between the first position  805  and the second position  810 . 
     The second blade  800  can have any desired degree of rotation as needed to suit a particular cutting procedure. In some instances, the second blade  800  is configured to rotate in a range of between 0 and 360 degrees, including any degree therebetween. In other cases, the second blade  800  is configured to rotate in a range of between 0 and 180 degrees, including any degree therebetween. In still other cases, the second blade  800  is configured to rotate in a range of between 0 and 90 degrees, including any degree therebetween. In certain embodiments, the degree of rotation of the second blade  800  can be adjustable. Such adjustability can advantageously help account for anatomic variations between patients. 
     The handle  600  defines a housing having an interior surface  626 . In some cases, the handle  600  comprises a single-piece structure. In other instances, the handle  600  comprises multiple sections, such as a first section  622  and a second section  624  that are coupled (e.g., molded) together. In some embodiments, the interior surface  626  of the handle  600  has a recess  630  formed therein. The recess  630  is sized and shaped such that the recess  630  is configured to receive a shaft  802  of the second blade  800 . Where the handle  600  includes the first section  622  and the second section  624 , the recess  630  is formed in at least one of the first section  122  and the second section  124  (and in some cases, both sections) of the handle  600 . The coupling of the second blade  800  and the handle  600  ensures that the handle  600  and the second blade  800  rotate together. 
     The handle  600  has an interior  604 . In some cases, the interior  604  of the handle  600  includes vertical side walls  606  and a medial wall  608  coupled to and extending horizontally between at least two of the vertical side walls  606 . The vertical side walls  606  and the medial wall  608  define a chamber  610  within the interior  604  of the handle  600 . 
     In certain embodiments, the tissue cutting device  500  further comprises a lock  860  ( FIGS. 13, 14, and 15 ). The lock  860  has a locked configuration and an unlocked configuration. When the lock  860  is in the unlocked configuration, the second blade  800  is rotatable from the first position  805  toward the second position  810 . When the lock  860  is in the locked configuration, the lock  860  is configured to restrain the second blade  800  from rotating relative to the first blade  700 . The second blade  800  is locked in the first position  805  when the lock  860  is in the locked configuration. 
     The tissue cutting device  500  also includes a cover  510 . The cover  510  is coupled to an upper end  605  of the handle  600 . The handle  600  is rotatable relative to the cover  510  to permit the second blade  800  to rotate from the first position  805  toward the second position  810 . In embodiments that include the lock  860 , the handle  600  is rotatable relative to the cover  510  when the lock  860  is in the unlocked configuration, whereas the handle  600  is restrained from rotating relative to the cover  510  when the lock  860  is in the locked configuration. 
     In certain embodiments, the cover  510  has a notch  512  formed therein (e.g., in a side surface thereof). The lock  860  is received in the notch  512  when the lock  860  is in the locked configuration. Then, the lock  860  can be disengaged from the notch  512  when the operator desires to cut a desired tissue. This in turn disengages the cover  510  from the handle  600  and allows the handle  600  to rotate relative to the cover  510 . In some cases, the cover  510  and the handle  600  are connected via snap fit notches that allow free rotation of the handle  600  relative to the cover  510  when the lock  860  is in the unlocked configuration. 
     In certain embodiments (not shown), the cover  510  includes more than one notch  512 . The cover  510  can include any desired number of notches  512 . Multiple notches  512  allow the operator to control axial rotation of the second blade  800  within a specified range (i.e., between adjacent notches  512 ) that is dictated by the notches  512 . For example, the cover  510  can include four notches  512 , each spaced equally apart about a perimeter of the cover  510 . In this non-limiting example, by rotating the second blade  800  between one or more adjacently positioned notches  512 , the operator is able to lock the second blade  800  in place after rotating the second blade  800  exactly 90 degrees, exactly 180 degrees, exactly 270 degrees, or exactly 360 degrees. 
     A top end  515  of the cover  510  has both a first opening  520  and a second opening  525  formed therein. The first opening  520  is configured to receive the first blade  700 . The second opening  525  is configured to receive the second blade  800 . In certain preferred embodiments, the first blade  700  is mounted within a slot defined by the first opening  520 . In some cases, the first blade  700  is glued within the slot. This, however, is by no means required. For instance, the first blade  700  can be mounted in the slot of the first opening  520  in any conventional manner. 
     In preferred embodiments, the first opening  520  is laterally offset from the second opening  525  so as to arrange the blades  700 ,  800  in an L-shaped configuration. This arrangement, which is shown in  FIG. 17A , helps prevent the entrapment of tissue, and allows the second blade  800  to rotate without interference from the first blade  700 . In other cases, the first opening  520  is centered between opposite sides of the cover  510 , such that the first  700  and second  800  blades are arranged in a T-shaped configuration. 
     The tissue cutting device  500  also includes a biasing member  530 . The biasing member  530  is positionable within the interior  604  of the handle  600 , particularly within the chamber  610 . In certain embodiments, the biasing member  530  is operably coupled to the lock  860  so as to resiliently bias the lock  860  into the locked configuration. In other cases (e.g., in embodiments where there is no lock  860 ), the biasing member  530  merely biases the handle  600  toward the cover  510 . In some embodiments, as shown in  FIGS. 13, 14, and 20 , the biasing member  530  is a spring. 
     Certain embodiments of the tissue cutting device  500  further include a projection  540 . The projection  540  is attached to the lock  860 . The projection  540  is also positionable within the interior  604  of the handle  600 , particularly within the chamber  610 . When in an uncompressed state, the biasing member  530  is configured to urge against the projection  540  so as to provide upward force to the lock  860  to retain the lock  860  in the locked configuration. The projection  540  is also configured to apply a counterforce to the biasing member  530  (so as to compress the biasing member  530 ) when the lock  860  is moved from the locked configuration to the unlocked configuration. In preferred cases, the lock  860  (whether in the locked or unlocked configuration) is positioned nearer to the cover  510  than is the projection  540 . 
     In some embodiments, the tissue cutting device  500  includes an actuator  550 . The actuator  550  is coupled to the lock  860  and is configured to move the lock  860  between the locked and unlocked configurations. In certain embodiments, the handle  600  has a slot  602  formed in an outer surface  603  thereof. The actuator  550  is slidably mounted in the slot  602  and is movable between a first position and a second position (e.g., using the operator&#39;s thumb or other finger). Slidable movement of the actuator  550  between its first and second positions causes the lock  860  to move between its locked and unlocked configurations. In more detail, when the actuator  550  is in the first position, the lock  860  is in the locked configuration. When the actuator  550  is in the second position, the lock  860  is in the unlocked configuration. When the lock  860  is received in the notch  512  of the cover  510 , the notch  512  is aligned with the slot  602 . 
     In certain embodiments, the lock  860  is positioned between the projection  540  and the actuator  550 . However, in alternative embodiments, the lock  860  and the projection  540  can be vertically aligned with respect to each other and each coupled to the actuator  550 . 
     In certain embodiments, to use tissue cutting device  500 , the operator pulls the actuator  550  toward a bottom end  680  of the handle  600  (i.e., a proximal end of the device  500 ). This in turn causes the lock  860  to be pulled away from (and out of) the notch  512 . Thus, the actuator  550  can be pulled to disengage the lock  860 , thus allowing the second blade  800  to rotate from the first position  805  toward the second position  810 . 
     An outer surface  570  of the actuator  550  can optionally comprise a material, or include surface features, configured to facilitate gripping of the actuator  550 . For instance, in some embodiments, the outer surface  570  of the actuator  550  comprises rubber or another suitable gripping material. In addition or alternatively, the outer surface  570  of the actuator  550  can include surface features, such as textured ridges, to facilitate sliding of the actuator  550  between its first and second positions. 
     In alternative embodiments, the cover  510  is devoid of an actuator  550  and notches  512 , and instead is merely activated by friction. In such cases, the tissue cutting device  500  can include at least one tooth (e.g., a plurality of teeth) or any high-friction surface (e.g., rubber). The teeth or high friction surface of device  500  are configured to restrain the handle  600  from rotating relative to the cover  510  such that the handle  600 , when rotated, can be locked into any position along a 360-degree arc about the cover  510 . The teeth (or high-friction surface) can be provided on the cover  510 , on the handle  600 , or on both the handle  600  and the cover  510 . Where the teeth (or high-friction surface) are provided on the cover  510 , the handle  600  is restrained from rotating relative to the cover  510  when the teeth (or high-friction surface) are in contact with an adjacent surface of the handle  600 . Where the teeth (or high-friction surface) are provided on the handle  600 , the handle  600  is restrained from rotating relative to the cover  510  when the teeth (or high-friction surface) are in contact with an adjacent surface of the cover  510 . In use, the handle  600  is pulled away from the cover  510  to compress the biasing member  530 . The handle  600  can then be rotated any desired degree relative to the cover  510  to rotate the second blade  300  any desired degree from the first position  805  toward the second position  810 . 
     The dimensions of tissue cutting device  10 , tissue cutting device  500 , and tissue cutting device  900  are not limited to the particular dimensions shown, but instead, can have any dimensions needed to suit a particular cutting procedure. For instance, a width and/or length of the first blade  200 ,  700 , the second blade  300 ,  800 , the handle  100 ,  600 , and/or the housing  120  can be varied as desired. 
     The present disclosure also provides a method of using the cutting devices  10 ,  500 ,  900  to cut the soft tissue (e.g., ligament, fascia, or tendon) of a patient. In certain embodiments, the present disclosure provides a method of performing an A1 pulley release procedure to treat trigger finger. However, it should be understood that the present methods can be used to cut any soft tissue structure. 
     Generally, the method of the present disclosure includes the steps of (a) providing a soft tissue cutting device  10 ,  500 ,  900 ; (b) advancing the tissue cutting device  10 ,  500 ,  900  to a body region; (c) rotating the second blade  300 ,  800  from the first position  305 ,  805  to the second position  310 ,  810 ; and (d) cutting soft tissue in the body region using the second blade  300 ,  800  when the second blade  300 ,  800  is in the second position  310 ,  810 . Unless stated otherwise, for any method of the present disclosure, any of tissue cutting devices  10 ,  500 , or  900  can be used. As described below, the step of advancing the tissue cutting device  10 ,  500 ,  900  to the body region involves using the first blade  200 ,  700  to introduce the tissue cutting device  10 ,  500 ,  900  into the body region. 
     In preferred embodiments, the method includes applying anesthetic to the patient&#39;s skin. Thereafter, the device  10 ,  500 ,  900  is placed through and into the patient&#39;s skin adjacent a desired tissue plane. In some cases, the device  10 ,  500 ,  900  is placed deep to the desired tissue plane such that the tissue to be cut is positioned above the cutting device  10 ,  500 ,  900 . However, the exact positioning of the device  10 ,  500 ,  900  will depend on the configuration of the first blade  200 ,  700  and the second blade  300 ,  800 , as well as on the type of cutting procedure to be performed. 
     For the methods of the present disclosure, a small incision is made in the patient&#39;s skin. In some cases, this incision can be made by using the first blade  200 ,  700  where the outer surface of the first blade  200 ,  700  includes a cutting blade. In other cases, particularly where the outer surface of the first blade  200 ,  700  is a blunt end, a separate device (i.e., a device other than device  10 ,  500 , or  900 ) is used to make the incision. 
     The first blade  200 ,  700  is then placed into subcutaneous tissue of the patient such that the outer surface of the first blade  200 ,  700  is adjacent a desired tissue plane. Preferably, this placement is performed under ultrasound guidance. During the insertion and initial placement of the device  10 ,  500 ,  900  into the patient&#39;s body, the second blade  300 ,  800  remains in the first position  305 ,  805 . Then, when it is desired to cut the tissue, the handle  100 ,  600  can be rotated to cause the second blade  300 ,  800  to rotate from its first position  305 ,  805  toward its second position  310 ,  810  so as to become an exposed blade. A cutting surface  315 ,  815  of the second blade  300 ,  800  is then used to cut the tissue in a customary manner. As discussed above, the manner of cutting using the second blade  300 ,  800  will vary depending on the particular type of cutting surface  315 ,  815 , and its location on the second blade  300 ,  800 . For example, the second blade  300 ,  800  may need to be pushed or pulled to cut the tissue. Once the tissue is cut, the device  10 ,  500 ,  900  is pulled out of the incision to complete the surgical procedure. The device  10 ,  500 ,  900  can optionally be discarded after use. 
     Use of embodiments of the device  900  shown in  FIG. 21  may include steps in addition to those noted above. For example, when inserting the device  900 , the flanges  425 ,  430  help prevent the operator from inserting the device  900  too far into the body region. Once the device  900  is positioned, an operator can apply rotational force to the second blade  300  (for example, by rotating the handle  100 ) to cause the one or more break points  450  to disrupt, thereby separating the first blade  200  from the second blade  300 . In certain embodiments, the operator can apply shear force (e.g., by pulling or pushing) the handle  100  to cause the one or more break points  450  to disrupt, thereby separating the first blade  200  from the second blade  300 . The first blade  200  and the second blade  300  thereby become separate devices. The operator can then freely move and rotate the second blade  300  to perform cutting. After cutting, the operator can grasp the handle  100  and pull the second blade  300  to remove it from the body region. The first blade  200  can remain in the body until after the second blade  300  is removed. The operator can then grasp the flanges  425 ,  430  of the first blade  200  with fingers and then pull the first blade  200  to remove it from the body region. 
     Due to the presence of actuator  550  in certain embodiments of device  500 , use of device  500  may include steps in addition to those noted above. In particular, once the positioning of device  500  is confirmed (e.g., under ultrasound), the operator can slide the actuator  550  from the first position to the second position to disengage the lock  860  from the notch  512 . The operator then rotates the handle  600  to rotate the second blade  800  from the first position  805  toward the second position  810 . Cutting of the tissue of interest (e.g., the A1 pulley) can then be performed by moving the second blade  800  in a conventional manner against the tissue. For embodiments that do not include the actuator  550  or notch(es)  512 , the handle  600  is merely pulled away from the cover  510  to compress the biasing member  530 , and the handle  600  is then rotated any desired degree relative to the cover  510 . 
     In some cases, the method is an A1 pulley release procedure for treating trigger finger. In such cases, the distal end  205 ,  705  of the first blade  200 ,  700  is placed deep to (i.e., below) the A1 pulley and superficial to (i.e., above) the flexor tendon group. The device  10 ,  500 ,  900  is initially flat (i.e., parallel to the patient&#39;s hand) and placed distal to proximal to the A1 pulley such that the distal end  205 ,  705  of the first blade  200 ,  700  faces toward the patient&#39;s wrist. In such cases, the device  10 ,  500 ,  900  is properly positioned when the first blade  200 ,  700  is located above the tendon, the second blade  300 ,  800  is located above the first blade  200 ,  700  and below the A1 pulley, and the patient&#39;s skin is located above the A1 pulley. Thereafter, the handle  100 ,  600  is rotated so as to rotate the second blade  300 ,  800  from its first position  305 ,  805  toward its second position  310 ,  810 . This rotation exposes the second blade  300 ,  800  to the A1 pulley. The second blade  300 ,  800  is then used to cut the A1 pulley, for example, by moving the second blade  300 ,  800  in a retrograde manner (i.e., proximal to distal) against the A1 pulley. 
     For the above-described methods, and with respect to devices  10  and  900  in particular, upward force from the tendon, as well as a counterforce from the A1 pulley, help keep the second arm  405  parallel to the plane of the A1 pulley while the second blade  300  rotates from the first position  305  to the second position  310 . 
     While tissue cutting devices  10 ,  500 , and  900  have been described as having first and second blades, skilled artisans will appreciate that alternative cutting mechanisms can be used. For example, in some embodiments, the first blade, second blade, or both can be replaced with a cutting mechanism configured to use electricity, heat, radiofrequency, or laser to cut soft tissue. Except for the type of cutting mechanism, such tissue cutting devices are otherwise the same as those that have been described above and can generally be used in a similar manner. 
     While some preferred embodiments of the invention have been described, it should be understood that various changes, adaptations and modifications may be made therein without departing from the spirit of the invention and the scope of the appended claims.