Patent Publication Number: US-2023149031-A1

Title: Methods and apparatus for minimally invasive bunion surgery

Description:
CROSS-REFERENCE TO THE RELATED APPLICATION 
     This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Application No. 63/264,246, filed on Nov. 18, 2021, the entire contents of which are incorporated herein by reference 
    
    
     TECHNICAL FIELD 
     The disclosed subject matter relates generally a guide system and method to aid an orthopedic surgeon in translating the distal bone fragment and inserting a k-wire into the bone. 
     BACKGROUND 
     Minimally invasive bunion surgery, also known as percutaneous bunionectomy, is a surgical procedure that seeks to correct a bunion deformity by utilizing a small incision. Hallux Valgus is a deformity of the big toe joint wherein a deviation of the big toe towards the lesser toes results in a prominent bump, or bunion. 
     During a minimally invasive bunion procedure, a surgeon will create an osteotomy in the first metatarsal and then translate a portion of the metatarsal longitudinally prior to installing fixation e.g., Kirschner wire (“k-wires”). Prior art methods require one instrument to be used for translation of the distal bone fragment and another to be used for k-wire targeting. Maintaining adequate translation while applying and using the targeting guide can be cumbersome and represents a challenge to the surgeon. 
     During any surgery, and minimally invasive surgery in particular, surgeons utilize K-wires to both stabilize the position of bones and to serve as guide wires for screw insertion. It is not uncommon for surgeons to require multiple k-wire insertions before they place the guide wire into the desired position. However, repeated k-wire insertions require time, increase frustration during the procedure, and represent micro-injuries to the bone that the body must heal in addition to the surgical correction. 
     Current guides/jigs for use in MIS bunion surgery require the surgeon to continuously hold the translation instrument in place in order to maintain the desired translation while targeting the fixation wires. One example, US Patent Application Publication 2020/0060698 entitled SCREW TARGETING GUIDE SYSTEM AND METHOD describes a handheld targeting guide for MIS bunion surgery, the entirety of which is herein incorporated by reference. The current subject matter presents a jig that combines both features into one instrument and independently maintains the desired translation while the surgeon places the fixation wires. 
     Reducing the number of instruments, maintaining the desired translation, and enabling the surgeon&#39;s hands to focus on k-wire insertion would be beneficial to both the surgeon and patient. Thus, given the deficiencies in the prior art, there remains a need for an improved apparatus to aid in MIS bunion surgery. 
     SUMMARY 
     The embodiments described herein are directed to a system, apparatus, and method for bunion correction utilizing a guide for translating the metatarsal head with respect to the metatarsal shaft subsequent an osteotomy and guiding a k-wire utilized in the fixation of the head and shaft in the relative translated position. In addition to or instead of the advantages presented herein, persons of ordinary skill in the art would recognize and appreciate other advantages as well. 
     In some embodiments, a system for performing a percutaneous bunionectomy is provided. The system including a jig having a body, a shaft contact pad connected to the jig body and conformed to the soft tissue proximate the metatarsal shaft, an arm extending in a longitudinal direction from the jig body, a metatarsal head contact pad connected to the arm and configured to conform to the soft tissue proximate the metatarsal head; a track rigidly connected to the second arm end and movably connected to the jig body and a circular track cooperating with an engagement mechanism of the track, such that a rotation of the track drive results in a lateral movement of the track. The system further includes an alignment guide arm connected to and extending longitudinally from the jig body and a plurality of positioning k-wires, attaching each of the metatarsal head contact pad and the metatarsal shaft contact pad through a multi-dimensional fixation hole to the metatarsal bone. A guide wire is also provided in the system for insertion through the displaced shaft and head of the metatarsal to assist in the subsequent insertion of a fixation screw. 
     In some embodiments, a method is provided, the method including the steps of creating an incision in the soft tissue of the foot, positioning a jig upon the soft tissue surrounding the metatarsal bone; securing the jig to the metatarsal bone and, via the incision cutting the metatarsal bone, creating a first portion of the metatarsal and a second portion of the metatarsal. The method further includes translating the jig track to laterally displace the second portion with respect to the first portion; adjusting the visual alignment guide to a desired trajectory; and inserting a fixation k-wire as a screw guide through the first and second portions of the metatarsal such that a fixation screw may permanently fix the bone portions in the laterally displaced position. In the method, the jig is subsequently removed from the metatarsal and the incision is closed. 
     In yet another embodiment, a translation and insertion jig for insertion of a k-wire is presented. The jig having a body, a shaft contact pad connected to the jig body and conformed to the soft tissue proximate metatarsal shaft, an arm extending in a longitudinal direction from the jig body, a metatarsal head contact pad connected to the arm and configured to conform to the soft tissue proximate the metatarsal head; a track rigidly connected to the second arm end and movably connected to the jig body and a track drive cooperating with an engagement mechanism of the track, such that a rotation of the track drive results in a lateral movement of the track. The system further includes a lock configured to selectively restrain the track from translation relative to the jig body and an alignment guide arm connected to and extending longitudinally from the jig body 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features and advantages of the present disclosures will be more fully disclosed in, or rendered obvious by, the following detailed descriptions of example embodiments. The detailed descriptions of the example embodiments are to be considered together with the accompanying drawings wherein like numbers refer to like parts and further wherein: 
         FIG.  1    is an isometric illustration of a translation and insertion jig in accordance with some embodiments of the disclosed subject matter; 
         FIG.  2    illustrates the translation and insertion jig positioned on the soft tissue near the metatarsal bone of the foot in accordance with some embodiments of the disclosed subject matter; 
         FIG.  3    illustrates the translation and insertion jig secured to the metatarsal bone via k-wires in accordance with some embodiments of the disclosed subject matter; 
         FIG.  4    illustrates the translation and insertion jig attached to the metatarsal bone subsequent an osteotomy of the metatarsal bone and prior to the lateral displacement of the metatarsal bone head via the jig in accordance with some embodiments of the disclosed subject matter; 
         FIG.  5    illustrates the translation and insertion jig attached to the metatarsal bone subsequent to the lateral displacement of the metatarsal bone head via the jig in accordance with some embodiments of the disclosed subject matter; 
         FIGS.  6 A and  6 B  illustrate in a lateral and A-P view, respectively, the insertion of a guide wire into the metatarsal shaft and laterally displaced head via a visual guide on the translation and insertion jig in accordance with some embodiments of the disclosed subject matter; 
         FIG.  7    illustrates the track drive and released lock in accordance with an embodiment of the disclosed subject matter; and 
         FIG.  8    is a flow chart of a method of performing MIS bunion surgery with the translation and insertion jig in accordance with embodiments of the disclosed subject matter. 
     
    
    
     DETAILED DESCRIPTION 
     The description of the preferred embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description of these disclosures. While the present disclosure is susceptible to various modifications and alternative forms, specific embodiments are shown by way of example in the drawings and will be described in detail herein. The objectives and advantages of the claimed subject matter will become more apparent from the following detailed description of these exemplary embodiments in connection with the accompanying drawings. 
     It should be understood, however, that the present disclosure is not intended to be limited to the particular forms disclosed. Rather, the present disclosure covers all modifications, equivalents, and alternatives that fall within the spirit and scope of these exemplary embodiments. The terms “couple,” “coupled,” “operatively coupled,” “operatively connected,” and the like should be broadly understood to refer to connecting devices or components together either mechanically, or otherwise, such that the connection allows the pertinent devices or components to operate with each other as intended by virtue of that relationship. 
       FIG.  1    illustrates a translation and insertion jig  100  for minimally invasive bunion surgery. The jig includes a body  110  which extends from its first end  112  configured to face the bone to a second end  114 . The jig  100  includes a metatarsal shaft contact pad  122  connected to the first end  112  of the jig body  110 . The shaft contact pad  122  is preferably conformed to the portion of soft tissue (e.g., skin, muscle, fat, fibrous tissue, blood vessels, or other supporting tissue of the body) covering the foot proximate to the metatarsal shaft to which it is intended to engage (e.g. concave). The contour of the shaft contact pad  122  may be conformed during surgery to match the soft tissue surrounding the bone, or pre-contoured. The shaft contact pad  122  may also be selectable by the surgeon from a plurality of different sizes and shapes, such that the jig  100  may have a set of interchangeable contact pads, or pads that attach to the first end  112 . The shaft contact pad  122  along with the head contact pad  124  discussed later, include at least one k-wire insertion hole  126 ,  128  that allows multi-dimensional fixation (i.e., restraint of relative movement in the vertical, lateral and longitudinal directions) of the pads  122 ,  124  to the respective shaft and head of the metatarsal bone (as shown in  FIG.  3   ). 
     Within or upon the jig body  110  is a linear track  140  extending in the lateral direction, the track  140  rigidly connected to the second end  134  of the extending arm  130  and movably connected to the jig body  110 . The linear track  140  includes an engagement mechanism, which, shown in  FIGS.  1 - 7   , is the rack of a rack and pinion mechanism which includes a toothed surface  142 . The track  140  alternatively may have a threaded surface such as in a lead screw mechanism. The track  140  is retained to the jig body to allow only lateral movement.  FIG.  4    illustrates a groove  117  in the jig body  110  that retains the track  140  in one embodiment, of course other known retention methods are also envisioned. The track  140  may be incremented to enable the surgeon to ascertain the amount of lateral translation and may be further indexed to move one increment (click) at a time, via indentations and ball stops (not shown), or other indexing mechanism known in the art. 
     The jig  100  has a longitudinal extending arm  130 , a second end  134  of the arm  130  attached to a track  140 . As with the shaft contact pad  122  and the head contact pad  124  discussed later, the extending arm  130  may be contourable, pre-contoured, or modular such that different sizes and shapes may be selected by the surgeon to be attached directly or indirectly to the track  140 . On the other end  132  of the extending arm  130  is a second contact pad  124  for the engagement of the soft tissue surrounding the metatarsal head proximate the pad  124 . The contour of the head contact pad  124  may also be conformed during surgery to a shape that matches the soft tissue proximate the bone (e.g. concave) or pre-contoured. The head contact pad  124  may also be selectable by the surgeon from a plurality of different sizes and shapes, such that the jig  100  may have a set of interchangeable contact pads, or pads inserts that attach to the first end  132  of the arm  130 . The arm  130  may include a longitudinal section  131 , a lateral section  133  and a vertical section  135  to position the head contact pad  124 . The longitudinal section  131  and the vertical section  135  may be adjustable by the surgeon to adjust the position of the head contact pad  124 , or alternatively may be selectable from a plurality of sizes and shapes in the same manner discussed above. 
     A track drive  150  (see also,  FIGS.  4 ,  7   ), including a manual knob  155 , dial, or wheel is rotatably connected to the jig body  110 , at least a portion of the knob or dial wheel extending outside the jig body  110  to be accessible for manual engagement. The track drive cooperating with the engagement mechanism of the track  140 . As shown in  FIGS.  1  and  7   , the track drive  150  includes a circular gear with intermeshing teeth  157  that functions as a pinion in a rack and pinion mechanism, the rack and pinion may also engage frictionally with high friction surfaces on the pinion  150  and cooperating track  140 . Alternatively, the track drive may be a worm drive, an internally threaded wheel of a lead screw mechanism, or a ball thread drive, each of which translates rotation of the knob, dial or wheel into linear lateral advancement of the track  140  (i.e., rotation of the track drive moves the track  140  and arm  130  laterally. Each increment of rotation of the circular drive (pinion) or length of track (rack) may be biased into position with known methods such as stop points achieved using teeth or ball plungers so that the track clicks into a plurality of positions laterally spaced from the jig body. Additionally, each increment may be of a predetermined measurement such as a mm or fraction thereof. 
     A track lock  160  is attached to the jig body  110  configured to selectively restrain the track from translation relative to the jig body  110 . The track lock  160  when engaged prevents the track  140  from retracting laterally and in some embodiments prevents any lateral translation irrespective of direction. The track lock  160  may take the form of a ratchet, allowing the track to advance but not retract, an interlock  162  (as shown in  FIG.  7   ) in which the lock  160  does not allow any translation. The track lock  160  is preferably biased in a locking position, freeing the surgeon from holding the jig to maintain the bone displacement. The track lock  160  may directly engage the track  140  to prevent its translation, or may engage the track drive  150  preventing it from rotating and thus restrict translating. The track lock  160  may alternatively be a threaded restraint screw (not shown) tightened to frictionally engage either the track  140  or drive  150 , and loosened to release the same, or vice versa. The track lock  160 , shown in  FIGS.  3  and  6   , is biased in the locked position by a spring  163  and released by pressing button  164  removing the interlock  162  from the pinion gears  157 , as shown in  FIG.  7   . With respect to alternative embodiments in which the track drive  150  is a lead screw or worm drive, the mechanical configuration largely limits the need for a track lock  160  since the track  140  cannot drive the track drive  150 , thus locking the track  140  in place. 
     An alignment/targeting guide arm  170  is removably attached to the jig body  110  and extends longitudinally from the jig body  110 . A post  172  extends vertically from an end of the alignment guide arm, and visual alignment rod  174  is attached to the post which is selectively rotatable about a vertical axis with respect to the alignment guide arm  170  for establishing the desired trajectory in the A-P plane. Although not shown a second visual alignment rod which is selectively rotatable about a horizontal axis with respect to the alignment guide arm may also be beneficial in establishing the desired trajectory in the lateral plane. The post  172  may feature one or more holes  176   a,b  aligned with the alignment rod  174 . These holes  176   a,b  may be beneficially sized to accept 3.0 mm and/or 4.0 mm MICA Screw k-wires, for insertion into the metatarsal portions using the jig  100 . The visual alignment rod  174  may be created via hole in the vertical post  172  through which a k-wire is inserted to serve as the visual alignment rod  174  when fluoroscopy is used. The alignment guide  170  may also incorporate sleeves through which k-wires are inserted to ensure the wires enter the bone at the proper trajectory. 
       FIG.  2    illustrates the jig  100  positioned on the soft tissue (not shown) proximate the metatarsal  210  of a foot  201 . The shaft contact pad  122  is positioned upon the soft tissue covering the metatarsal shaft  211  and the head contact pad  124  is positioned upon the soft tissue covering the metatarsal head  212 . As shown in  FIG.  1   , the track  140  and arm  130  are in the retracted or initial position. The extending arm  130  may be configured with respect to the anticipated incision location so as not to interfere with the osteotomy instruments access to the metatarsal bone  210  via the incision. As shown in  FIG.  2   , the shape of the extending arm  130  leaves an access area  280  to the metatarsal  210  between  270  and  360  degrees. 
       FIG.  3    illustrates the attachment of the jig  100  to the metatarsal bone  210  via k-wires  324  and  322 . The respective k-wires  322  and  324  are inserted through holes  126  and  128  in contact pads  124  and  122  respectively through the soft tissue and into the shaft  211  and head  212  of the metatarsal  210 . The holes  126  and  128  are preferably oriented to direct the k-wires into the bone to ensure multi-dimensional fixation of each of the contact pads  122  and  124  to the shaft  211  and head  212  of the metatarsal bone  210 . The multi-dimensional fixation of each portion of the metatarsal bone  210  is desirable to ensure the jig  100  remains secured to the respective bone portions subsequent the osteotomy. 
     In  FIG.  4   , the jig  100  positioned on the metatarsal bone  210  is shown subsequent to the osteotomy  410 . As a result of the osteotomy  410 , the metatarsal  210  is divided into a shaft portion  412 , including the shaft  211 , being attached to the shaft contact pad  122  and a head portion  414  including the head  212  being attached to the head contact pad  124 . The track  140  and extending arm  130  are shown in a retracted position or initial position prior to the translation of the head portion  414  with respect to the shaft portion  412  via the jig  100 . 
       FIG.  5    illustrates the jig  100  with the track  140 , arm  130  and the head contact pad  124  extended to the desired location selected by the surgeon. As can be seen in  FIG.  5   , at the osteotomy  410 , the head portion  414  has been translated laterally from the shaft portion  412  by λ. The track  140  is configured to laterally translate from a first position as shown in  FIGS.  2 ,  3  and  4    to a fully translated position including any intermediate surgeon selectable position as shown in  FIGS.  5  and  6 B . The track  140  is restrained to a predetermined path, typically a straight line, however, it may be beneficial in some circumstances for the path to be curved or not linear. 
     Turning to  FIGS.  6 A and  6 B , the insertion of the guide wire  601  through the shaft portion  412  and head portion  414  of the metatarsal  210  is shown. With the translation λ established and maintained via the jig  100 , the k-wire  601  is placed through the k-wire hole ( 176   a,b ) in the post  172  and inserted into the metatarsal  210  following the trajectory established by visual guide rod  174 . A screw may then be guided by the guide wire  601  into the shaft portion  412  and head portion  414  of the metatarsal to fix the translation λ throughout the healing period. Because of the lock  160  or the inherent nature of the track drive  150 , the displacement λ is maintained by the jig  100  without the necessity of surgeon&#39;s attention or hands, which are freed for the insertion of the guide wire  601  and ultimately the fixation screw (not shown). 
     The visual guide  174  enables the surgeon to visualize the relative position of the surgical k-wire  601  within both portions of the bone  210 .  FIG.  6 B  illustrates an anterior posterior (A-P) view, i.e. looking down upon the foot  201 . The visual guide rod  174  is coincident with the surgical k-wire  601  when the k-wire  601  is following the prescribed trajectory in the A-P view as shown in  FIG.  6 B . If a second visual guide is provided, it would be coincident with the surgical k-wire  601  when the k-wire  601  is following the prescribed trajectory in the lateral view, generally shown in  FIG.  6 A . Thus the location and movement of the inserted k-wire  601  in the A-P view may be represented by the visual guide rod  174 , additionally, the visual guide rod  174  may also be rotatable with respect to the horizon and thus act as an insertion guide in the lateral plane (i.e. the plane normal to the lateral direction), though it requires the surgeon to account for the vertical offset in the lateral view. Likewise, in  FIG.  6 A , the second guide rod (not shown) may govern movement of the inserted k-wire  601  in the lateral plane. Thus between the top and side views of  FIGS.  6 A and  6 B  respectively, the location and trajectory of the inserted k-wire  601  may be represented in three dimensions and thus monitored and controlled using one or two visual guide rods. 
       FIG.  8    illustrates a method  800  for performing a percutaneous bunionectomy using the jig  100 . First, as is common in a conventional percutaneous bunionectomy, an incision in the soft tissue of the foot  201  of a patient is created by the surgeon as shown in Block  802 . The jig  100  is positioned upon the soft tissue (not shown) proximate the metatarsal bone  210  of the foot  201  as shown in Block  804  (see also  FIG.  2    which illustrates the jig  100  on the soft tissue proximate the metatarsal  210 ). As properly positioned, the shaft contact pad  122  and a head contact pad  124  of the jig  100  are proximate the shaft  211  and head  212  respectively of the metatarsal bone  210 . 
     In Block  806 , the jig  100  is secured to the metatarsal bone  210  as illustrated in  FIG.  3   . In  FIG.  3   , the jig  100  is secured to the bone via k-wires  322  and  324  inserted through the contact pads, soft tissue and into the bone, however it is envisioned other fastening devices (i.e. screws, pins, clamps etc.) may also have beneficial applications. 
     In Block  808 , the metatarsal bone is accessed through the incision and is cut creating first and second portions  412  and  414  of the metatarsal  210 , the result of the osteotomy  410  is illustrated in  FIG.  4   . The jig track  140  is then translated by manually rotating knob  155  of the track drive  150  such that the desired displacement λ is achieved between the two portions as shown in Block  810 .  FIG.  5    illustrate the track  140 , arm  130 , head contact pad  124  and head portion  414  of the metatarsal with the desired displacement λ. As noted above, the locking mechanism  160  or the mechanical configuration of the track drive  150  prevents the track  140  from retracting, thus in some embodiments, the locking mechanism must be activated subsequent translation, or in the case where the locking mechanism  160  is biased in a locking position, the locking mechanism would be released to allow the translation of the track  140 . 
     As shown in Block  812 , the visual guide rod  174  of the alignment guide  170  is adjusted to the desired trajectory.  FIG.  6 B  illustrates the visual guide rod  174  aligned along the surgeon selected trajectory. In Block  814 , a guide wire is inserted through the first and second portions  412  and  414  of the metatarsal  210  to fix the first and second portions in the laterally displaced position.  FIG.  6 A  illustrates the k-wire  601  inserted through the shaft portion  412  and the head portion  414  when they are displaced by λ. The surgical k-wire  601  is positioned through one of the guide holes  176 a,  176 b and into the soft tissue of the foot  201 . The k-wire  601  is advanced while aligning it with the visual guide rod  174  in the A-P plane, and if a second guide rod is provided, then aligning the k-wire  601  with the other guide rod in the lateral plane. The surgeon may check the position in both A-P and lateral planes to determine trajectory of surgical k-wire and adjust as needed. These latter steps typically require use of fluoroscopy to confirm intended trajectory has been achieved. The surgical k-wire  601  is advanced into the bone while maintaining the desired trajectory in the lateral and A-P planes with reference to the respective visual guides. The surgical k-wire may be advanced incrementally and its position and orientation again verified via the visual guide as it is advanced. As noted, a fluoroscope is preferably used to visualize the bone and the surgical k-wire with reference to the visual guide. Thus, it is preferable that the visual guide rod  174  is not X-ray permeable, so it will appear on the fluoroscope. As shown in Block  816 , the jig  100  is removed from the metatarsal  210 . Subsequent removal of the jig  100 , the surgeon may use a depth gage placed over the guide k-wire  601  to measure screw length. The surgeon then places a drill over the k-wire  601  with a cannulated drill, then inserts a fixation screw over the k-wire to properly fixate the osteotomy. The guide wire  601  is then removed. A second screw may also be placed lateral to this screw depending on patient anatomy and needs. The incision is closed in Block  818 . 
     The visual guide  170 , as discussed above, may have one or more guide rods that extend parallel to the surgical k-wire and serve as representations of the surgical k-wire within the respective planes, to assist in its proper insertion. 
     Another aspect of the disclosed subject matter is that the visual guides may be any narrow elongated straight rod, strip or bar that achieve the desired goal of visually referencing the position of the surgical k-wire being inserted. Examples may be rods formed from plastic, ceramic, metal or organic material, or composites thereof. For materials that are x-ray permeable, non-permeable material may be added to enable the guide to be visible under a fluoroscope. 
     While the jig  100  shown in  FIGS.  1 - 7   , is configured for the left foot, it is equally envisioned that the jig could be likewise configured for the right foot, or even configured for universal use on both the left and right feet with minor adjustments as understood by one skilled in the art. Additionally, although the disclosed subject matter is described with respect to a rack and pinion system (i.e. the track is the rack and the drive is the pinion) other configurations are also envisioned, such as a worm drive for translating the track, ball-screw drive system, or a lead screw system. Additionally, while the lock is described with respect an interlock key, other configurations, such as a frictional lock or ratcheting lock are also envisioned. 
     The method shown in  FIG.  8   , describes the positioning and securing of the jig  100  prior to the creation of the incision, and/or the osteotomy. However, one or both of the incision and the osteotomy may be performed prior to the positioning and/or securing of the jig  100 . In the case where the osteotomy is preformed prior to the securing of the jig  100 , the jig  100  need not account for access  280  to the bone  210 , other than for the guide wire  601  and subsequent fixation screw. 
     Another aspect of the disclosed subject matter is that although the jig  100  is described in view of minimally invasive bunion surgery, it may also be useful in other osteotomies in which portions of a bisected bone are displaced relative to one another, as may be appreciated by those skilled in the art. 
     Although the methods described above are with reference to the illustrated flowchart, it will be appreciated that many other ways of performing the acts associated with the methods can be used. For example, the order of some operations may be changed, and some of the operations described may be optional. 
     The foregoing is provided for purposes of illustrating, explaining, and describing embodiments of these disclosures. Modifications and adaptations to these embodiments will be apparent to those skilled in the art and may be made without departing from the scope or spirit of these disclosures.