Patent Description:
The present disclosure relates to a system and method for harvesting a tendon, and in particular for harvesting a Quadriceps Tendon (QT).

The quadriceps tendon is often used as a source of tissue graft for ligament surgery, such as anterior cruciate ligament (ACL) reconstruction. However, graft harvesting from the QT presents several challenges, as the QT is larger and stronger than other tendons, resulting in a tough fibrous bundle of tissue that tends to resists accurate consistent dissection. Furthermore, in order to reduce incisions around the target area, harvesting is preferably performed though a small incision near the knee. This may result in a second person retracting the skin away from the anterior QT surface while the surgeon wrestles with this tendon tissue. Existing devices may require multiple cuts to dissect this tough tissue. The fibrous tendon tissue may deviate related art devices from their intended cutting path, rendering an uneven and potentially useless graft strip cross section. Further difficulty occurs when terminating the graft at the proximal end of the strip, and at the furthest distance from the skin incision near the knee. Without making a larger or second skin incision, this proximal cut may be performed somewhat blind, and therefore time-consuming and risking inadvertent tissue damage. Therefore, there is a need for an improved system and associated method that can consistently remove a target sized strip of tendon tissue from the native tendon, overcoming the issues disclosed herein.

<CIT> relates to a vein harvesting system and method. <CIT> relates to a tendon harvesting system. <CIT> relates to a direct vision subcutaneous tissue retractor and method for use.

Described herein is a system including a plurality of devices for harvesting a tissue graft from surrounding tissue, such as a QT. Defining the entire QT as the native tissue, the system and methods described herein are configured to disconnect a portion or strip of this native tissue from itself. Before being harvested or disconnected, this portion or strip is continuous with and non-discernable from the native tissue. Stated in another way, the portion or strip disconnected by the herein disclosed system is originally continuously coupled to the native tissue, along the entire length of the resultant strip, including at least three side surfaces of the resultant strip. The systems that form the graft strip dissects a continuous length through the native tissue along the entire length of the resulting strip or portion. The shape of the resultant portion or strip is defined by the system disclosed herein and can be altered with differing dimensions and methods of use of the disclosed systems, and cutting tools. Contrary to this, a vessel-harvesting tool for example, disconnects a target vessel from surrounding connective tissue along its length that may include smaller vessels and other connective and fatty tissues that are not remaining native vessel. It follows therefore, that this example harvested strip of vessel tissue (the target vessel) is disconnected from a plurality of tissues that are different from the target native vessel; the target native vessel is not a removed portion of itself along its entire length of the harvested vessel. The target native vessel is discernable from the connective tissue around it. It is coupled along its length to a plurality of tissues, and these tissues are different in composition to the target native vessel. In addition, the vessel itself at least partially defines the shape and size of the harvesting tool or the harvested tissue. As a further example, a polyp removal device disconnects a polyp from a substrate tissue, the polyp and substrate tissue not being the same tissue, and the polyp only coupled to the substrate at a first end of the polyp. In addition, the polyp is discernable from the substrate tissue and a device that disconnects a polyp does not define the boundary of polyp removed. The entire polyp is removed, the polyp defining the boundary.

Disclosed herein is a system that may be used to form a graft strip from the native tendon. It includes a static retractor that is flexible for insertion through a small skin incision, and is self-supporting, once under the skin. Retractor is configured to allow instruments access into a working cavity along the tendon, and may include features for improving access to the tendon. For example, retractor may include a pocket to selectively engage a guide, and place the guide along the tendon. While installed within the retractor, the guide may be configured to guide a trajectory and depth of cut of a dual blade scalpel along the tendon, so as to forms lateral sides of the graft strip. The retractor may also provide access to a proximal end of the tendon, such that a proximal cutter may transect a proximal end of the graft.

Disclosed herein is a retractor that is self-supporting for holding open an anatomic space developed in a patient. The retractor may be configured to hold open an anatomic space adjacent a tendon such as the QT, the space configured for harvesting a tendon graft from a portion of native tendon. The retractor may define an elongate body, with a proximal end, a distal end, a roof that defines a curved surface and a floor that defines a planar surface for engaging a surface of the tendon or tissue adjacent thereto. The retractor may define an elongate working cavity extending from an open distal end. The roof may include at least one opening extending therethrough, defining boundaries of bilateral wings at a distal end of the elongate body. The retractor is configured to be elastically collapsed to insert though a relatively small incision through the skin and into the anatomic space. The retractor may elastically collapse from a first (neutral) configuration to a second configuration that is collapsed or has a smaller profile than the first configuration, by external forces on the bilateral wings body. Release of the external forces on the retractor is configured to relax the retractor towards the first configuration and hold the anatomic space open without external support.

In some example embodiments, the roof may include a roof relief at a proximal end of the elongate body, the roof relief defining a <NUM> degree bounded hole configured to add flexibility to the retractor and thereby further decrease the collapsed profile of the retractor in the second configuration. In some example embodiments, the floor planar surface includes an elongate opening therethrough, the opening having a lateral width sized to provide visibility and tool access to an entire tendon width. In some example embodiments, the retractor also includes a means of engaging a cutting guide and orienting the cutting guide along the working cavity. In this example, the means of engaging and orienting may orient a shaft of the cutting guide along the working cavity, parallel to a longitudinal axis of the elongate body. In this example, the means of engaging and orientating may include a pocket extending from a proximal end of the working cavity, for receiving a cutting guide end therein. In some example embodiments, the retractor may provide audible feedback upon correct engagement of the cutting guide within the pocket. In some example embodiments, the distal end of the retractor defines an entrance into the working cavity, for receiving a guide tool and a harvesting tool simultaneously therethrough.

Another example embodiment of a retractor that is self-supporting is disclosed herein. Retractor may hold open an anatomic space developed in a patient for harvesting a tendon. The retractor may include an elongate body formed of a flexible material and include a proximal end, a distal end, a longitudinal axis, a roof having a curved surface and a floor having a planar surface for engaging a surface of the tendon. The elongate body may define an elongate working cavity extending from an open distal end. The distal end may define bilateral wings having free distal most ends. These bilateral wings are configured to be pinched towards each other, to temporarily reduce a profile of the retractor for easier insertion through a skin incision. Release of the bilateral wings are configured to relax the wings away from each other such that the retractor tents the anatomic space open without external support.

In some example embodiments, the roof may include an elongate roof opening that defines a roof boundary of the bilateral wings. Pinching of the bilateral wings moves the bilateral wings towards each other and into the elongate roof opening. In some example embodiments, the retractor includes a roof relief at a proximal end, the roof relief defining a <NUM> degree bounded hole configured to further reduce a profile of the retractor during insertion through the skin incision. In some example embodiments, the floor includes an elongate opening therethrough defining a floor boundary of the bilateral wings. In some example embodiments, the retractor includes a pocket extending from a proximal end of the working cavity, for receiving a cutting guide end therein. The retractor may also include a tab opening, configured to engage with the cutting guide upon engagement of the cutting guide within the pocket, the tab opening configured to provide audible feedback upon engagement In some example embodiments, the distal end defines an entrance into the working cavity, for receiving a guide tool and a harvesting tool simultaneously therein.

An example system for harvesting a tendon graft is also disclosed, including a retractor, a guide, and a harvesting tool. The retractor is self-supporting for holding open an anatomic space developed in a patient above the tendon. The retractor comprises a flexible elongate body including a proximal end, a distal end, a longitudinal axis, a roof that is curved and a floor having a planar surface for engaging a surface of the tendon. The retractor defines an elongate working cavity extending from an open distal end. The guide has a handle end, a working end and an elongate shaft extending therebetween. The guide is configured to assemble with the retractor and fix the guide shaft along the working cavity. The guide's working end may define a dissecting leading edge. The harvesting tool includes a handle end and a working end with an elongate shaft extending therebetween. The harvesting tool's working end including a blade edge for cutting into the tendon and a contoured surface for engaging and translating along the guide shaft while in the working cavity. The guide shaft and contoured surface are configured to limit the trajectory and translation extent of the harvesting tool along the tendon.

In some example systems, the retractor may include bilateral wings having free distal most ends. The bilateral wings may be flexed and pinched towards each other to reduce a profile of the retractor temporarily for insertion through a skin incision. Release of the bilateral wings are configured to relax the wings laterally away from each other and tent the anatomic space open without external support. The retractor may include a pocket extending from a proximal end of the working cavity, for receiving the guide's working end therein and thereby orienting the guide shaft along the working cavity. In some example systems, the retractor has a distal opening sized to receive both the guide and the harvesting tool simultaneously therethrough. Some example systems may also include a proximal cutter, configured to extend along the working cavity and transect a tendon graft.

The disclosure will be more fully understood by reference to the detailed description, in conjunction with the following figures, wherein:.

In the description that follows, like components have been given the same reference numerals, regardless of whether they are shown in different examples. To illustrate example(s) in a clear and concise manner, the drawings may not necessarily be to scale and certain features may be shown in somewhat schematic form. Features that are described and/or illustrated with respect to one example may be used in the same way or in a similar way in one or more other examples and/or in combination with or instead of the features of the other examples.

As used in the specification and claims, for the purposes of describing and defining the invention, the terms "about" and "substantially" are used to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. The terms "about" and "substantially" are also used herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue. "Comprise," "include," and/or plural forms of each are open-ended, include the listed parts and can include additional parts that are not listed. "And/or" is open-ended and includes one or more of the listed parts and combinations of the listed parts. Use of the terms "upper," "lower," "upwards," and the like is intended only to help in the clear description of the present disclosure and are not intended to limit the structure, positioning and/or operation of the disclosure in any manner.

Referring now to <FIG>, an overview of an example system <NUM> is illustrated, including a retractor <NUM> and a plurality of instruments including but not limited to a blunt dissector <NUM>, dual blade scalpel <NUM> and proximal cutter <NUM>. All or some parts of the disclosed system may be used, in combination with other instrumentation to harvest a tendon strip or graft from a native tendon. The system <NUM> is configured to remove a strip of tendon tissue from the native tendon, consistently and reliably, according to the predetermined strip length, width and depth. The system <NUM> may be configured to lie between the patient knee and a proximally disposed quadriceps muscle. As such, throughout this disclosure, the term "distal" relative to portions of the system define portions closer to the knee, and the term "proximal" define portions of the system that are closer to the patient thigh or quadriceps muscle, Stated in another way, the terms proximal and distal relate to the patient throughout this specification, rather than the tool use.

The system includes a retractor <NUM> that is self-supporting and may be configured for insertion into a small incision near the knee. Retractor <NUM> is preferably placed subcutaneously and along the surface of the Quadriceps Tendon, hereinafter "QT". The retractor preferably lies on the anterior surface of the QT. The retractor <NUM> forms a working cavity for access to and visibility of the QT. Retractor <NUM> is configured to provide access for the plurality of instruments of the system to the tendon via the working cavity. Retractor <NUM> is configured to hold the working cavity open or tent the skin away from the tendon surface without requiring external forces, and is thereby self-supporting. External forces that are not required include for example a positioning arm or stand, a robot arm, or a second person with a paddle retractor. The retractor <NUM> is configured to receive and/or operatively engage and guide the plurality of instruments, such as dissector <NUM>, harvester <NUM> and proximal cutter <NUM>, while forming the strip of tendon tissue.

The blunt dissector <NUM> may perform a plurality of functions, both independent of other portions of the system <NUM>, and while assembled thereto. For example, the blunt dissector <NUM> may dissect the tissue before the retractor <NUM> is inserted. Blunt dissector <NUM> may also operatively couple to the retractor <NUM> to provide a handle for retractor insertion and manipulation. Blunt dissector <NUM> may also provide a trajectory guide to limit the trajectory of the harvester <NUM>. In some system embodiments, a separate tool may dissect the tissue first. The harvester <NUM> may be configured to form two lateral sides of the tendon strip simultaneously, using portions of the retractor <NUM> and blunt dissector <NUM> as a guide to control the cut trajectory. The proximal cutter <NUM> may slide along the retractor's working cavity and along a partially dissected tendon strip and disconnect the proximal end of the tendon strip from the native tendon.

Turning now to the details of the individual components of system <NUM>, and starting with the retractor <NUM>, a variety of views are illustrated in at least <FIG>. Retractor <NUM> may be a unibody or single molded element, formed of a flexible material. Retractor is configured to be collapsed, or reduced in profile and then inserted through an incision and under the skin. Once inserted, retractor <NUM> is generally self-supporting and configured to hold open the anatomic space it is inserted into for performing minimally invasive surgical procedures. The retractor <NUM> defines an elongate body, with proximal and distal ends, and may have a general arch shape or "C" shaped cross-section, defining a passage and longitudinal working cavity therealong. Retractor <NUM> preferably includes a rounded, tapered or streamlined shape along its length to facilitate insertion along the dissected space anterior of the tendon, with minimized tissue trauma. Retractor <NUM> proximal end <NUM> may be enclosed, with a lower profile than distal end <NUM>. Retractor floor defines a planar lower surface <NUM> along its length, to lie relatively flat on an anterior surface of the QT. The QT may not necessarily be perfectly flat, but is considered mostly planar along its length, to engage a substantial portion of the planer lower surface <NUM>. Retractor <NUM> may be formed of a plastic, and may be translucent to facilitate better tissue visualization. In addition to being formed of a flexible material, retractor <NUM> also includes a plurality of reliefs to improve elastic deformation of the retractor <NUM>, for easier insertion through the incision and under the skin. However, the retractor <NUM> is sufficiently rigid to return towards its non-deformed shape once under the skin, and push the skin up to form a tent or working cavity. This provides the surgeon with a working cavity on the target tendon, the tendon readily visualized through the incision and open distal end <NUM> of retractor <NUM>. Retractor <NUM> may include flanges 1117a, 1117b extending radially from a distal end <NUM> of retractor <NUM>. Flanges 1117a, 1117b may mirror images of each other, either side of the longitudinal axis of the retractor <NUM> and may extend orthogonal to the longitudinal axis. Flanges 1117a, 1117b may maintain a location of retractor relative to the skin incision. Flanges 1117a, 1117b may remain external to and directly adjacent the skin incision when retractor <NUM> is inserted. Flanges 1117a, 1117b may act as a stop, limiting insertion depth of the retractor <NUM> into the anatomical space.

Retractor <NUM> defines a proximal end <NUM> that is tapered and a distal end <NUM> defining an opening for a surgeon to have direct visualization of the target tendon and place instruments therethrough. Retractor <NUM> may be of any length that is suitable for harvesting the QT, and may be generally between <NUM>-<NUM> inches long in its entirety, and define a working cavity having a cross sectional dimension "W" between <NUM>-<NUM> inches. Since the skin incision is as small as possible, preferably no wider than an inch, the retractor is configured to collapse and fit through this small incision and then pop open once inserted.

Retractor <NUM> may define a shell body. Retractor <NUM> may include a plurality of reliefs <NUM> and <NUM>. A proximal relief <NUM> may provide additional retractor flexibility while also providing an access window for an optional scope or light source. These optional instruments may extend through the skin directly adjacent relief <NUM> and then through relief <NUM>. Relief <NUM> may define a <NUM> degree (°) bounded hole, the boundary defined entirely by the retractor <NUM>. Relief <NUM> may be oblong in shape having a longer opening dimension across the width of retractor <NUM>.

Roof relief <NUM> may extend from a distal end <NUM> of retractor <NUM>, up to and including the distal most edge. Roof relief <NUM> therefore defines a slot that has an open distal end. Roof relief <NUM> may define a boundary with elongate ribs <NUM> that extend around at least a portion of the boundary of relief <NUM>. Ribs <NUM> may aid in further tenting the skin and may add some resilience to limit the skin from collapsing the retractor <NUM> when inserted. Roof relief <NUM> defines a medial boundary for bilateral wings 1112a, 1112b either side of the retractor <NUM>. Wings 1112a, 1112b may be squeezed or pinched together during insertion into the skin incision. As shown in <FIG>, wings 1112a, 1112b are sufficiently flexible to touch or nearly touch for easy insertion through a relatively small incision. During pinching, the wings 1112a, 1112b move into the roof relief <NUM> space.

Retractor has a cross sectional width W (<FIG>) that is preferable wider than the QT, to better identify surrounding structures. Retractor <NUM> defines an upper curved roof portion <NUM>, bilateral sidewalls 1125a, 1125b (including the wings 1112a, 1112b), and bilateral stands 1126a, 1126b. The upper curved roof portion <NUM> and bilateral sidewalls 1125a, 1125b are configured to lift or tent the skin. The bilateral stands 1126a, 1126b may define planar surfaces of the floor <NUM> that may engage both the anterior surface of the QT and tissue lateral to the QT. For access to the anterior QT surface, bilateral stands 1126a and 1126b are laterally disposed and define an elongate medial opening <NUM> along the retractor <NUM>. Bilateral stands 1126a and 1126b may define a smaller width opening (G2) towards the proximal end <NUM>. Small width opening G2 may be uniform along its entire length and may extend up to the proximal end of retractor <NUM>. This opening <NUM> may limit a trajectory of a cutting tool along the retractor <NUM> and thereby along the target tendon. Medial opening <NUM> may extend from a distal-most edge of retractor <NUM> and extend along a substantial portion of retractor length, best seen in at least <FIG> and <FIG>. Medial opening <NUM> may be bounded by straight edges 1131a, 1131b, that are parallel to retractor longitudinal axis L-L. Medial opening <NUM> may by coextensive with relief <NUM>. Medial opening is configured to provide access for a harvester <NUM> to the QT anterior surface.

Seen best in at least both <FIG>, <FIG> and <FIG>, proximal end <NUM> includes a nose <NUM>, extending proximally from relief <NUM>. Nose <NUM> includes a pocket <NUM> that is continuous with the working cavity. Pocket <NUM> is configured to selectively operatively engage with a working end of a guide tool such as dissector <NUM>. In some embodiments, a guide tool may aid insertion and general handling of the retractor <NUM>. Guide tool may have a handle end, opposite the working end that extends along the retractor <NUM> and out of retractor distal end <NUM>. Shown in <FIG> pocket <NUM> may operatively engage with a guide tool. Pocket <NUM> may also include a means of positively engaging the example tool. Pocket <NUM> may be sized to slideably receive guide tool working end, with a little clearance except for at a plurality of discrete locations, where crush ribs <NUM> are located. <FIG> illustrates example locations of crush ribs <NUM>, that may extends along the longitudinal axis for a distance. Crush ribs <NUM> are sized to locally reduce the pocket size and more positively engage a guides working end.

Pocket <NUM> may also include a means of providing positive audible feedback to the user that the guide tool is correctly engaged with pocket <NUM>. Aperture <NUM> for example may click as a corresponding mating tab snaps therein and engages the aperture <NUM>. Blunt dissector <NUM> may include a protruding key or tab, shown in at least <FIG> that is received by aperture <NUM>. Aperture <NUM> may define an axis perpendicular to the retractor long axis. Aperture <NUM> may, in combination with tab on dissector <NUM>, increase retention between the retractor <NUM> and blunt dissector <NUM>. Audible feedback, or a clicking feel once correctly inserted may compensate for obscured visibility when engaging the guide tool (dissector <NUM>) while the retractor <NUM> is already inserted. Since the guide tool (dissector <NUM>) defines a trajectory of a cutting tool into the tendon, the correct insertion of the guide tool is important. Removal of the dissector <NUM> from the retractor <NUM> may require deformation of the flexible retractor <NUM> adjacent the aperture <NUM> to remove the mating tab <NUM> from the aperture <NUM>.

Details of the blunt dissector <NUM> are illustrated in at least <FIG>. Blunt dissector <NUM> generally includes a handle end <NUM>, working end <NUM> and a shaft <NUM> extending therebetween. Working end <NUM> includes a leading edge <NUM> that may be linear across its extent and is generally blunt, configured to separate tissue layers. Blunt dissector <NUM> may be inserted through incision near the knee and advanced under the skin, to bluntly separate the skin layers from the anterior QT surface. As such, leading edge or dissecting edge <NUM> is preferably not so sharp to cut or pierce tissue. It may however break through connective tissue connecting the QT anterior surface from the skin layers. Blunt dissector <NUM> may be configured to clear away the fat pad under the skin. Blunt dissector <NUM> may perform this separation before inserting the retractor <NUM>.

Handle end <NUM> may be angularly offset from the working end <NUM>. Shaft <NUM> may include a bend, forming the angular offset. Shaft <NUM> defines a distal length portion 1230a, extending directly from handle <NUM>. Shaft distal length portion 1230a may define a first cross section that is circular. Angular offset may be formed along the distal length portion 1230a. Angular offset may be between <NUM>-<NUM> (°) degrees and is configured to align the shaft proximal portion 1230b along the tendon surface while angling the handle <NUM> around a bent knee and out of the way. Shaft proximal length portion 1230b may be non-circular. Proximal length portion 1230b may define a straight linear length, configured to lie on or lie parallel to the relatively flat QT anterior surface. Proximal length portion cross section may include at least one planar surface <NUM> that extends along the proximal length portion 1230b, on a top side thereof, seen best in <FIG>. In some embodiments, cross section defines an inverted "V" cross section or an inverted cropped "V". This cross section including the planar surface <NUM> is configured to engage and guide a translation of a tendon-cutting tool, such as dual blade scalpel <NUM>, described in more detail later. Other possible configurations to guide and limit a trajectory of a cutting tool may include elongate slots or elongate rails along the dissector <NUM> that operatively engage a mating feature of a cutting tool.

Proximal end of blunt dissector <NUM> is shown in more detail in 4D. Shaft proximal length portion 1230b may include length indicators <NUM> to indicate a length of QT or depth of insertion of the dissector <NUM> along the QT. In some embodiments, working end <NUM> may include indicators or markings (not shown) along the leading edge <NUM>, transverse the longitudinal axis of the shaft <NUM> for estimating a width of tissue. Working end <NUM> may be wider than shaft <NUM>, and may be termed a spatula. A tapered edge <NUM> may extend between the shaft proximal length portion 1230b and leading edge <NUM>. Tapered edge <NUM> may extend bilaterally from both sides of the shaft <NUM> and, in some embodiments, may include a scalloped or cutting edge that may dissect connective tissue while retracting the blunt dissector <NUM> (moving it distally). Tapered edge <NUM> may also limit a trajectory extent of a cutting tool, as will be described later.

Top side of working end <NUM> may include a tab or key <NUM> to positively engage a mating feature of retractor <NUM>. Tab <NUM> may be oblong and define a protruding element that inserts into aperture <NUM>. Tab <NUM> may define a major length that is smaller than aperture <NUM>, allowing some lateral movement between the tab <NUM> and aperture <NUM>, while limiting translation along the retractor longitudinal axis. <FIG> shows an example cross section of shaft proximal portion 1230b; including a lower side or surface <NUM> that may be flat to engage the anterior surface of the QT. Superior surface <NUM> is configured to engage and guide trajectory of a cutting tool, as will be explained hereinafter. Superior surface <NUM> may be an inverted "V" or inverted cropped "V" and shaft portion 1230b may defining three surfaces angled relative to each other.

<FIG> illustrate various views of the dissector <NUM> assembled with the retractor <NUM>, the retractor <NUM> translucent in <FIG> for ease of understanding. Working end <NUM> of blunt dissector may be selectively received by pocket <NUM> of retractor <NUM>. Pocket <NUM> may frictionally engage working end <NUM>. Pocket may include a plurality of discrete ribs <NUM> to increase grip between the retractor <NUM> and dissector <NUM>. Pocket <NUM> may be sized relative to the working end <NUM> such that retractor <NUM> may deform or flex to receive working end <NUM> therein. Pocket <NUM> and blunt dissector <NUM> may be coupled to aid insertion of retractor <NUM> along the QT anterior surface. Alternatively, blunt dissector <NUM> may be couplied once the retractor <NUM> is inserted. When inserted along the QT anterior surface, lower surface <NUM> may engage a portion the QT anterior surface and the shaft portion 1230b may align with longitudinal axis or retractor <NUM> and preferably along a target cutting trajectory of the tendon. Blunt dissector <NUM> may help in moving the retractor around while identifying the target cutting trajectory.

<FIG> illustrates various views of a dual blade harvester <NUM>, configured to form two lateral sides of a resulting tendon strip <NUM>' simultaneously, hereafter termed "Harvester". Relative to the patient, harvester <NUM> forms two elongate cuts along the tendon <NUM>, including a lateral and medial cut. Harvester <NUM> includes a handle <NUM> and working end <NUM>, with an elongate shaft <NUM> therebetween. Shaft <NUM> and handle <NUM> may both extend along the same longitudinal axis. In other words, handle <NUM> and shaft <NUM> may not include any bend or angular offset, similar to the blunt dissector <NUM>. Handle <NUM> and shaft <NUM> may include reusable or multi use components, with a detachable working end <NUM>. In some embodiments, the working end <NUM> is coupled to shaft <NUM> via a release sleeve (not shown). In other embodiments, working end <NUM> may define a housing <NUM> fixedly coupled to shaft <NUM> and include engagement means <NUM> to selectively attach to blades <NUM>, illustrated in <FIG>. Engagement means <NUM> may include elongate tabs, one each on lateral external surfaces of housing <NUM>. Engagement means may be oriented at an angle that defines a location of a leading cutting edge of blades <NUM> and thereby depth of cut into the tendon. Blades <NUM> may be standard scalpel blades. It is preferable that blades <NUM> be single use and therefore consistently sharp for each procedure, as sterilization methods for reusable surgical tools tend to dull sharp edges. Harvester <NUM> may be provided in varying configurations that may define selectable widths and depths of cut through and along the tendon. The different configurations may have differing widths and/or place the blades <NUM> at differing angles to define the widths and depths of cut through and along the tendon. The two blades <NUM> may preferably be parallel to each other, and form two equivalent cut depth into and along the QT simultaneously. Example lateral distances between blades <NUM>, defined by housing <NUM> may be between <NUM>-<NUM>, and may more preferably be between <NUM>-<NUM>.

Turning now to <FIG> and <FIG>, housing <NUM> defines a lower surface that may include an elongate channel <NUM>, the channel having a cross section that receives and operatively slides with guide proximal shaft 1230b therein. Channel <NUM> may define a cross section shape that may form a sliding fit with shaft 1230b of guide <NUM>, as illustrated in <FIG>. Channel <NUM> may mate and slide along mating surface <NUM> of blunt dissector. The channel <NUM> and blunt dissector shaft 1230b are configured to guide the trajectory and depth of cut of the harvester <NUM> and thereby the blades <NUM> along the retractor <NUM> and into the tendon. The lower surface <NUM> of blunt dissector <NUM> may engage the tendon anterior surface. In other embodiments, only the retractor lower surface may engage the QT anterior surface. Depth D of cut may therefore be defined and controlled by the configuration of blades <NUM>, the working end <NUM> and shaft 1230b.

<FIG> illustrates the retractor <NUM> placed on the tendon anterior surface <NUM>, with the dissector <NUM> assembled and iinserted into retractor pocket <NUM> and the harvester <NUM> entering the retractor distal end <NUM> and cutting into the tendon <NUM>. <FIG> illustrates the harvester <NUM> after translation along the tendon <NUM>, at a proximal end of the retractor <NUM>. <FIG> illustrates a view of retractor proximal end <NUM> with housing <NUM> visible through relief <NUM>. <FIG> illustrates the harvester <NUM> and dissector <NUM> in a position similar to the shown in both <FIG> and <FIG>, with the retractor <NUM> removed for simplicity of understanding. In this location, blunt dissector <NUM> may abut a surface of the harvester <NUM> to limit the extent of this trajectory, thus proximally limiting the harvester translation. Tapered edge <NUM> of dissector <NUM> for example may be configured to limit the trajectory of harvester <NUM>, by abutting a distal surface <NUM> and thereby blocking further translation. In other embodiments, a surface of the retractor may limit translation of harvester <NUM>.

<FIG> illustrate a cross section of the harvester <NUM> engaging the dissector <NUM> in a first position corresponding to <FIG>. Harvester <NUM> may be at a distal end <NUM> of retractor. <FIG> illustrate a cross section of the harvester <NUM> engaging the dissector <NUM> in a second position corresponding to <FIG> where the harvester <NUM> has translated along the guide <NUM> towards the proximal end of retractor <NUM>. Comparing <FIG> with <FIG>, it can be seen that the harvester angle α reduces as the harvester <NUM> translates further into the retractor's working cavity. Channel <NUM> is preferable contoured along its longitudinal axis to at least partially compensate for the changing angles of approach and maintain a substantially contact cut depth. For example, in the first position, the harvester is orientated at a larger angle of approach (angle α) relative to the shaft <NUM> and tendon anterior surface <NUM>. A proximal contoured surface portion 1324a of channel <NUM> (shown in <FIG>) engages the dissector shaft 1230b. Contoured surface portion 1324a may define a convex curved surface, coextensive with blade leading edge 1340a. In the second position, the harvester <NUM> is orientated at a shallower angle of approach (angle α) and a distal contoured surface portion 1324b of channel <NUM> engages the dissector shaft 1230b. Contoured surface portion 1324b may define a linear surface, axially spaced and distal from blade leading edge 1340a. Contoured surface portions 1324a and 1324b define a cutting depth "D" that is the same, despite the variation in the angle of approach, provided the contoured surface portions engage the surface <NUM> of dissector <NUM>.

The system <NUM> may also include a proximal cutter <NUM>, configured to separate a proximal end of tendon strip from native tendon <NUM>, details of which are shown in at least <FIG>. This cutting operation occurs furthest from the skin incision making reliable cuts in the target area more difficult to achieve, Without the proximal cutter <NUM>, this cut end may be an uneven, jagged end, frustrating later suturing and coupling techniques. Proximal cutter <NUM> forms a clean and uniform cut end, which makes later handling of the tendon graft easier. Proximal cutter <NUM> includes a replaceable blade <NUM> that is selectively operatively coupleable to a distal end of proximal cutter shaft <NUM>. Having a fresh blade <NUM> for each procedure ensures a consistent sharp edge and a more consistent and precise uniform slice through the fibrous tendon tissue. Sterilization methods of reusable instrument may tend to dull sharp edges.

Proximal cutter <NUM> includes a handle end <NUM> and a guillotine style cutter at a working end <NUM> of the cutter <NUM>. A shaft <NUM> extends between the working end <NUM> and handle end <NUM>. Shaft <NUM> may include length estimation markers therealong and may include a static outer shaft and axially moveable inner pull rod <NUM>, which may be coaxially disposed along outer shaft. A blade housing <NUM> may extend from shaft <NUM>. Blade housing <NUM> may bilaterally extend from shaft <NUM>, the shaft longitudinal axis centrally disposed relative to the blade housing <NUM>. Blade housing <NUM> may define a longitudinal axis that is coincident with and parallel to a shaft longitudinal axis. Stated in another way, blade housing <NUM> longitudinal axis is preferably not angularly offset from shaft longitudinal axis.

Blade <NUM> defines a generally thin planar element with a connecting end <NUM> and cutting end <NUM> extending therefrom. Cutting end <NUM> includes an aperture <NUM> configured to receive a strip of tendon therethrough. Aperture <NUM> may define a <NUM> degree (°) bounded opening, with curved edges. Aperture <NUM> may be oblong and sized to receive a tendon strip that includes a bone block therethough. Aperture <NUM> may therefore define a cross section larger than the target graft strip width or cross section, as the bone block may be slightly larger and more rigid than the graft strip. This is termed a full thickness graft. Aperture <NUM> may have an effective diameter configured to receive a graft and bone block up to <NUM>. Aperture boundary may define an arc length 1412a that is sharp. Arc length 1412a may be transition to a less sharp arc length 1412b. Arc lengths 1412a and 1412b may generally face each other, with the sharp arc length 1412a along a furthest edge from handle <NUM>, defining a proximal side of the aperture <NUM>. In operation, a tendon strip is slid through aperture <NUM> and the working end <NUM> is slid along the tendon strip to a prepared tendon strip proximal end. Tension on the tendon strip while positioning the working end <NUM> tends to slide the tendon strip along a distal edge or arc length 1412b of aperture <NUM>. There may be some weaker tissue bridges forming some snagging discrete connections between a posterior surface of the tendon strip and anterior surface of remaining native tendon. Therefore, while arc length 1412b may be preferably less sharp than 1412a to avoid any unintended damage to the graft strip while placing the working end <NUM> at a strip proximal end, the distal side of aperture 1412b may be configured to break these snagging tissue bridges is preferable. Arc length 1412b may therefore have some sharpness, sufficient to break these tissue bridges along the tendon while advancing the cutter <NUM>.

Housing <NUM> defines a slot <NUM> extending through the housing longitudinal axis, for receiving the blade's connecting end <NUM> therethough. Blade connecting end <NUM> extends through to a distal or handle side of the housing <NUM> to couple to pull rod <NUM>. Housing <NUM> may include a curved leading edge <NUM> that may be sharp to cooperate with blade <NUM> while transecting the tendon strip. Leading edge <NUM> may also aid in breaking snagging tissue bridges while advancing the proximal cutter <NUM> along the strip <NUM>', in combination with aperture arc length 1412b. Housing <NUM> includes a lead-in to slot <NUM> to receive the blade <NUM> therein. Slot leading edge may be asymmetric, seen best in <FIG>, having a first distal edge surface <NUM> on a first side of the slot that is disposed on a first side of the blade <NUM> that is tapered and axially spaced from a second distal edge surface <NUM>. Second distal edge surface <NUM> is disposed on a second opposing side of the blade <NUM> and may extend further along blade <NUM>. This offset in distal edge surfaces (<NUM>, <NUM>) forms a lead in for the blade <NUM>.

Housing <NUM> includes an arced opening defined at least partially be edge <NUM> that may approximately match aperture <NUM> in size and shape. In operation, cutter <NUM> has two configurations. A first configuration shown in <FIG>, defining an open configuration, for receiving the tendon strip through aperture <NUM> When in the target location, retraction of the blade <NUM> may move the blade distally, towards the handle and into the housing <NUM> to transect the tendon strip. In this second or cut configuration the aperture, <NUM> is preferably reduced to beyond zero, such that arc length 1412a may be recessed or covered by housing <NUM>.

Actuation of the handle <NUM> retracts blade <NUM> to cut the tendon tissue. Handle <NUM> may include two levers 1432a, 1432b pivotally coupled to each other and may include at least one biasing member <NUM> therebetween. Lever 1432a may be fixed or static. Lever 1432b may be operatively coupled to a first end of pull rod <NUM> and activation (motion) of lever 1432b may axially retract pull rod <NUM> and thereby retract blade <NUM>. Handle <NUM> may define a pistol grip handle <NUM>. Lever 1432b may include a slot <NUM> that receives a pull rod pin <NUM> therethough, such that rotation of lever 1432b towards lever 1432a slides pin <NUM> and retracts pull rod <NUM>. Release of actuation forces on lever 1432b may spring lever 1432b back, to move the blade <NUM> to the open configuration, courtesy of biasing member <NUM>. Other mechanical constructs are contemplated by the inventors, known in the art that may retract a pull rod. In other embodiments, either or both lever arm may move relative to each other. Activation of handle is configured to move the blade <NUM> from a position that may receive the tendon therethrough to a position that covers the entire blade aperture <NUM> with housing <NUM>. Therefore, in some example embodiments, housing <NUM> may move and the blade <NUM> may be stationary. In other embodiments, both the housing <NUM> and blade <NUM> may move towards each other.

Handle <NUM> may include a lock out <NUM> configured to hinder inadvertent actuation of handle. Lock out <NUM> may be operatively coupled to a torsion spring <NUM>, configured to maintain lock out <NUM> in a position that prevents actuation of handle 1432b. An example mechanism is shown in <FIG> illustrating a surface <NUM> of lock out <NUM> that may engage a surface 1435b of handle 1432b, and thereby limit handle rotation. Rotation of locking out <NUM> moves surface <NUM> away from handle surface 1435b, allowing actuation thereof, shown in <FIG>.

Proximal cutter <NUM> defines a longitudinal axis L, and levers 1432a, 14232b extend along a first plane through longitudinal axis L. Housing <NUM> defines a maximum width Wm for receiving a corresponding maximum width of blade <NUM> therein. This orients aperture <NUM> such that a central axis through aperture <NUM> is perpendicular to the first plane. In use, this orientation preferably orients levers laterally away from graft strip longitudinal axis. Relative to the patient anatomy, this orients the levers 1432a, 1432b either medially or laterally to the patient anatomy. This lever orientation preferably keeps the levers away from the knee joint and out of the field of view along the tendon <NUM>. In addition, guillotine blade <NUM> defines a thin planar element have planar surfaces that define the blade thickness, the planar surface extending along a plane that is parallel to shaft longitudinal axis L. Cutting edge 1412a axially translates during actuation, to move towards the handle end <NUM>. Cutting edge 1412a moves along a plane that is parallel to the first plane and parallel to the shaft longitudinal axis. Cutting edge 1412a defines a segment (arc length) of a <NUM>° (degree) bounded aperture <NUM> through the blade thickness, sized to receive an entire cross section of a tendon strip <NUM>' therethrough. <NUM>° (degree) bounded aperture <NUM> may also include an arc length 1412b that is configured to dissect tissue, but not as sharp as cutting edge. Arc lengths 1412a, 1412b may be opposite each other and may have an extent that is approximately equal in length to each other.

Blade <NUM> may operatively couple and detach from pull rod <NUM>. Connecting portion <NUM> may extend along lateral slots of outer shaft <NUM> and selectively couple to pull rod <NUM>. Connecting portion <NUM> and pull rod <NUM> may include a means to selectively couple and detach from each other. Connecting portion <NUM> may include at least one lateral tab <NUM> that may aid in detaching the connecting portion <NUM> from pull rod <NUM>. Connecting portion <NUM> may include bilateral tabs <NUM>. Connecting portion <NUM> may include aperture <NUM> disposed between the tabs <NUM> for engaging with a pin or protrusion on pull rod <NUM>, seen best in cross section image shown in <FIG>. Tab(s) <NUM> may provide a handle to manipulate the blade <NUM>, connect, and disconnect it from the pull rod from blade <NUM>. Tab(s) therefore define a boundary with blunt edges and may be held by the users hand.

In alternative embodiments, housing <NUM> and blade <NUM> may both be single use, replaceable sub-assembly. In some embodiments, the entire cutter <NUM> may be single use. In other embodiments the blade <NUM> may be stationary during cutting and housing <NUM> may move and advance over the blade <NUM>.

Proximal cutter <NUM> is configured to fit within retractor <NUM>, with both the guide <NUM> and harvester <NUM> removed. Housing width Wm may approximate a width W of retractor. Proximal cutter <NUM> may slide along graft strip and along retractor <NUM> to the proximal end of tendon, seen best in <FIG>.

<FIG> disclose a second system embodiment configured to harvest a tendon. This system includes a retractor <NUM> for improving visualization of the tendon, in a manner similar to retractor <NUM>. The system <NUM> may also include at least one modular insert (<NUM>, <NUM>), a dual harvester <NUM> and a proximal cutter <NUM>. Retractor <NUM> includes a means to couple with modular inserts (<NUM>, <NUM>), that guide the formation of a consistent graft strip from a native QT.

Similar to retractor <NUM>, retractor <NUM> is preferably flexible and may be collapsed and then placed through an incision under the skin. Upon release, retractor <NUM> forms a "tent", providing the surgeon visualization of the surgical site. Retractor <NUM> may be tapered along its length, having the larger distal opening <NUM> for inserting instruments and modular inserts therethrough. Retractor proximal end <NUM> may be closed so that tissue and fluid cannot enter the working cavity <NUM>. Retractor base <NUM> may engage an anterior surface of the QT and may include means to engage modular inserts (<NUM>, <NUM>). Base <NUM> may include rails <NUM> for example that received inserts (<NUM>, <NUM>) therein to assist the surgeon in performing the incisions required to harvest the tissue.

More specifically, the system may include a retractor <NUM>, a longitudinal floor insert <NUM>, a proximal floor insert <NUM>, a double blade harvester <NUM> for use with the longitudinal floor insert <NUM> and a proximal cutter or scalpel <NUM> for use with the proximal floor insert <NUM>.

A method of use may include making an incision through patient's skin near the patella and inserting a proximal end <NUM> of retractor <NUM> through the incision and advancing it along an anterior surface of the QT. The retractor <NUM> may be reduced in profile or collapsed for easier insertion through a skin incision, smaller than the neutral profile of the retractor <NUM>. Proximal end <NUM> may include a lip <NUM> that is inserted proximally beyond an end of QT. Retractor base <NUM> slides along and lies on the QT anterior surface. Advancing occurs until open end <NUM> is adjacent the initial skin incision and may be external to the patient skin, or slightly inserted within and under the skin, while maintaining the incision open. This provide improved visibility of the target tissue and improved access for insertion of instrument and modular inserts. A longitudinal floor <NUM> may then be inserted along the base (<FIG>). This floor <NUM> may slide along rails <NUM> of base <NUM>. Floor <NUM> may sit on a planar surface of retractor base <NUM>. Floor <NUM> may include an elongate slot <NUM> therethrough that may be selected based on the desired graft width and length. Floor <NUM> may include markings <NUM> to indicate a length. This slot <NUM> may define the graft width and length, and may come in a variety of sizes. A cutting tool or harvester, such as harvester <NUM> may then be inserted into the retractor's working cavity <NUM> and through elongate slot <NUM> to dissect a portion of the tendon from the native tendon. Edge surfaces <NUM> of elongate slot <NUM> may guide trajectory of harvester <NUM> Elongate slot may define a <NUM> degree bounded aperture that may limit translation of harvester <NUM> in a proximal and distal direction.

Harvester <NUM> may be a double bladed tool, similar to harvester <NUM> and may form two parallel cuts into and long the QT simultaneously. The two blades 2252a and 2252b may be parallel with each other and spaced apart laterally from each other to define a desired width of QT to be cut. At least one of the blades 2252a or 2252b may slide along one of the edge surfaces <NUM> of slot <NUM> to keep the cut aligned along the QT. A planar surface <NUM> of the harvester <NUM> may engage and slide along a top surface <NUM> of floor <NUM> to control a depth of cut into the QT.

Longitudinal floor <NUM> and harvester <NUM> may then be removed from base <NUM> and through distal opening <NUM>. Both a posterior side and patella end of the graft may then be cut, by using a scalpel to release the QT graft except for a proximal most end of the remaining graft strip. Proximal floor <NUM> may then be installed with base <NUM> (<FIG>). The patella end of graft may be lifted to slide proximal floor <NUM> under the graft tissue <NUM>' (see <FIG>). Proximal floor <NUM> includes a graft elevation ramp <NUM> at a proximal end that extends at an angle to the floor <NUM>. Ramp <NUM> extends across the width of floor <NUM> and includes a slot <NUM>. A scalpel <NUM> may then slide along top surface of floor <NUM> and through slot <NUM> to amputate the proximal end of graft <NUM>. Scalpel blade <NUM> may disposed at a non-zero angle to a shaft and handle, and blade <NUM> may be flush on a lower side <NUM> to ride along top surface of floor <NUM>.

A method of forming a graft is disclosed in <FIG>. The method may begin with making a minimally invasive incision at the superior pole of the patella. This incision <NUM> may be between <NUM>-<NUM> inches in length. Blunt dissector <NUM> may then be inserted through incision <NUM> to dissect around the tendon <NUM> (<FIG>). Blunt dissector <NUM> may clear away the fat pad under the skin. Blunt dissector <NUM> may perform this separation before inserting the retractor <NUM>. A dissecting edge <NUM> may be configured to separate the tissue layers. Length indicators along a shaft <NUM> of blunt dissector <NUM> may be used to verify that sufficient length of the tendon <NUM> has been separated from the subcutaneous layers of the skin. Blunt dissector <NUM> may then be removed from under the skin and may be coupled to retractor <NUM> (<FIG>). Retractor <NUM> may include a pocket <NUM> configured to receive working end <NUM> of blunt dissector <NUM> therein. Pocket <NUM> may include a plurality of discrete crush ribs <NUM> that form a local interference fit between the working end <NUM> and pocket <NUM>, to improve the grip. Once correctly engaged with each other, the user may receive positive feedback, such as an audible click. Pocket <NUM> may include an opening <NUM> that receives a tab <NUM> upon correct insertion, the insertion of this tab <NUM> into the opening <NUM> providing the audible feedback. Retractor <NUM> is preferably formed of a flexible material and pocket <NUM> may both elastically and plastically deform while operatively coupling to blunt dissector working end <NUM>. For example, the crush ribs <NUM> may plastically deform, while the pocket <NUM> may elastically deform. Coupling the blunt dissector <NUM> to the retractor <NUM> orients a guiding surface of the blunt dissector <NUM> along a length of the retractor <NUM>. The guiding surface is configured to guide a trajectory and translation extent of harvesting tools and thereby form a consistent graft tendon strip. Optionally a guide tool, different than blunt dissector1200 may be coupled to the retractor <NUM> to orient a guiding surface along the retractor. For example, a modular insert similar to floor <NUM> may be operatively coupled to a base of a retractor <NUM>.

With shaft and handle end of blunt dissector <NUM> extending from retractor end <NUM>, retractor <NUM> may be inserted through skin incision <NUM> and along tendon <NUM> (<FIG>). Retractor <NUM> is preferably flexible, and as such, inserting the retractor <NUM> may include collapsing or deforming the retractor, using external forces, to fit through the skin incision. These external forces may come from a device, a surgeon's hand and/or the patient's anatomy. For example, wings 1112a, 1112b may be flexed medially during insertion (illustrated in <FIG>). Flexing the wings 1112a, 1112b allows the retractor <NUM> to b e reduced in profile and pass through a relatively smaller incision. Retractor wings 1112a, 1112b may be released once mostly under the skin <NUM> and within the subcutaneous layer between the tendon anterior surface <NUM> and below the skin. Blunt dissector <NUM> may be used to position the retractor <NUM> along the tendon in the target orientation with the retractor end <NUM> adjacent or coincident with skin incision <NUM>. Release of external forces on the retractor <NUM> tents the skin away from the tendon anterior surface <NUM>. This presents the surgeon with a retracted opening at the skin incision, corresponding with distal opening <NUM> with a tented working cavity and access to the tendon. Preferably, the retractor <NUM> remains stationary and defines a working cavity at least as long as the target tendon strip length, and wider than the target graft strip width. Preferably, the working cavity is wider than the entire width of the target tendon. Insertion may be complete when a distal radial flange (1117a, 1117b) abuts the incision <NUM>. Flanges 1117a, 1117b may engage outer skin surface, limiting further retractor translation under the skin.

Optionally the retractor <NUM> may be inserted at least partially through the incision without the blunt dissector <NUM> assembled, and the blunt dissector <NUM> may be inserted after the retractor <NUM> is mostly in place. The retractor <NUM> may be more fully collapsed or reduced in profile when free of the blunt dissector <NUM>, which may allow the skin incision to remain smaller. Collapsing of the retractor to a minimal profile is facilitated by the combination of the plurality of openings and reliefs through the retractor <NUM> together with the retractor flexibility. Following along with this example method, the retractor <NUM> may be at least partially inserted through the skin incision in the collapsed configuration and once mostly under the skin, may be released to tent the skin away from the QT anterior surface. The blunt dissector <NUM> may then be inserted through the skin incision <NUM>, along the retractor <NUM> and into the pocket <NUM>. The user may be manipulate the dissector <NUM> within the pocket <NUM> until a feedback is detected indicating that tab <NUM> has been engaged with opening <NUM>, and therefore the blunt dissector <NUM> is correctly inserted within pocket <NUM>.

Optionally, shown in <FIG>, a second port through the skin <NUM> at a proximal end of tendon <NUM> may be formed and a scope <NUM> and/or light source may be placed through an aperture <NUM> of retractor <NUM>. A target width and depth of tendon strip may then be determined, and a working end of a harvester <NUM> may then be selected and assembled, corresponding to these targeted values. For example, a harvester <NUM> may be chosen, configured to form two lateral cut sides of the tendon strip <NUM>', defining a tendon strip width of about <NUM>. Other widths may include a <NUM> wide strip, or a <NUM> wide strip. Harvester <NUM> may then be inserted through retractor end <NUM> and into working cavity (<FIG>). Harvester <NUM> engages shaft <NUM> of dissector <NUM> to guide trajectory of blades <NUM> into and along the tendon <NUM>. This forms both lateral sides of the graft strip simultaneously. Harvester <NUM> may include a channeled surface <NUM> disposed between the two blades <NUM> that slides along a superior surface of the dissector shaft <NUM> to limit the depth of cut into the tendon and also the trajectory of the two lateral cuts along the tendon <NUM> to the proximal end of the tendon. In other embodiments, the harvester <NUM> may include a single blade, and only one lateral side may be formed at this stage. The dissector shaft <NUM> may engage an anterior surface of the tendon <NUM> while the harvester <NUM> is translated. The retractor end <NUM> allows access to both the dissector <NUM> and harvester <NUM> simultaneously, while providing visibility therethrough of the target tendon. The blunt dissector <NUM> may include at least one edge <NUM> that limits the extent of the harvester proximal trajectory. The harvester <NUM> therefore may slide along the dissector shaft up until it abuts this edge <NUM>. The harvester <NUM> may define arced blade edges such that retraction along the dissector shaft, towards the knee may also form lateral sides of the graft strip, or at least separate some remaining tissue bridges between the graft strip lateral sides and remaining tendon <NUM>. The harvester channel <NUM> may be contoured such that a depth of cut into the tendon <NUM> is relatively consistent along the length of the cuts, despite the angle of approach of the harvester <NUM>. The harvester <NUM> may begin cutting at a distal end at a first angle of approach, with a distal curved contoured portion of the channel <NUM> engaging the shaft <NUM>. The angle of approach may gradually become shallower as the harvester is advanced proximally such that a linear surface 1324b of the channel <NUM> may engage the shaft to limit a depth of cutting into to QT.

The dissector <NUM> and harvester <NUM> may then be removed, leaving the retractor <NUM> in situ. As shown in the graphic in <FIG> the two lateral side surfaces of the strip <NUM>' are now separated from the native tendon <NUM>. The distal and posterior separation may then be performed, represented in <FIG>, such that the graft strip <NUM>' is only coupled at a proximal most end to the native tendon <NUM>. This separation may be performed with a scalpel, with the retractor <NUM> remaining in place. Distal end of graft strip may then be threaded through an aperture <NUM> of proximal cutter <NUM> (<FIG>). Graft strip may be fed through aperture <NUM> and working end of proximal cutter <NUM> may extend through retractor end <NUM> along strip to the proximal end of graft strip, illustrated in <FIG> illustrates a close up of proximal cutter <NUM> with the strip <NUM>' extending through aperture and the retractor <NUM> removed for simplicity of understanding. Levers of proximal cutter <NUM> may extend either medially or laterally away from knee for improved visibility. Lock out member <NUM> of proximal cutter <NUM> may then be moved and the proximal cutter <NUM> actuated to amputate the graft strip <NUM>'. Blade <NUM> is retracted into housing <NUM> to amputate the graft strip <NUM>' Graft strip <NUM>', proximal cutter <NUM> and retractor <NUM> may then be removed.

Claim 1:
A retractor (<NUM>) that is self-supporting for holding open an anatomic space developed in a patient for harvesting a tendon therein, said retractor (<NUM>) comprising;
an elongate body defining a proximal end (<NUM>), a distal end (<NUM>), a roof that defines a curved surface and a floor (<NUM>), the elongate body defining an elongate working cavity extending from the distal end (<NUM>);
characterized in that the roof includes at least one opening defining bilateral wings (1112a, 1112b) at a distal end (<NUM>) of the elongate body, and wherein the elongate body is configured to be elastically collapsed from a neutral configuration to a collapsed configuration by external forces on the bilateral wings (1112a, 1112b), for insertion through a skin incision, and upon release of the external forces the elongate body is configured to relax towards the neutral configuration and hold the anatomic space open without external support,
wherein the floor (<NUM>) defines a planar surface (<NUM>) for engaging an anterior surface of the tendon.