Patent Publication Number: US-2023157710-A1

Title: Articulating curette for decorticating a vertebral endplate via a cannula

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This U.S. non-provisional patent application claims the benefit of and/or priority under 35 U.S.C. § 119(e) to U.S. provisional patent application Ser. No. 63/282,343 filed Nov. 23, 2021 titled “Articulating Curette,” the entire contents of which is specifically incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to medical instruments for spine procedures and, more particularly, to medical instruments for decorticating vertebral endplates of vertebrae of a spine via a cannula. 
     BACKGROUND OF THE INVENTION 
     Many people contend with spine issues due to age, disease, trauma, congenital, and acquired complications and conditions. While some spine issues can be alleviated without surgery, other spine issues necessitate surgery. Spine surgery may entail removing vertebral disc material from between adjacent vertebrae. This is now typically accomplished using minimally invasive surgery, micro invasive surgery or similar surgery. All such methods reduce trauma by using surgical instruments that are introduced into the body via one or more small incisions. Certain of these medical instruments are introduced into the body via a separate cannula, endoscope or the like (collectively, cannula) that has been inserted into the body through a small incision and positioned accordingly. The medical instrument is then inserted into the cannula and operated accordingly. 
     In cases where a vertebral disc is to be replaced with an interbody spine implant, the vertebral area needs to be prepared before the interbody spine implant is inserted in the vertebral disc space between the adjacent vertebrae. First, the vertebral disc and/or vertebral disc material is removed from the vertebral disc space of adjacent vertebrae, then the endplates of the adjacent vertebra facing the vacated vertebral disc space are decorticated or prepared for receiving the interbody spine implant. With both procedures, an appropriate medical instrument is used via the cannula. When preparing the vertebral end plates, a medical instrument with a head designed to decorticate the vertebral endplate is extended from the open end of the cannula where the head is manipulated to decorticate/prepare the vertebral endplates. 
     Heretofore, medical instruments for decorticating/preparing vertebral endplates have been limited in efficacy and/or efficiency. In one respect, such prior medical instruments are limited in the amount of vertebral endplate material they can remove in a single swipe. In another respect, such prior medical instruments are limited in their reach relative to the associated cannula. In still another respect, such prior medical instruments are limited in ease of use. Other limitations exist. 
     It would therefore be advantageous to have a better medical instrument for decorticating and/or preparing vertebral endplates through a vertebral disc space via a cannula in a minimally, micro or other surgical spine procedure that reduces surgical complexity. It would furthermore be advantageous to have a medical instrument for a minimally or micro invasive or similar spine procedure that provides greater removal of vertebral endplate material, greater degree of sweep, and extension beyond the perimeter of the cannula used with the medical instrument. 
     The present medical instrument addresses the above and more. 
     SUMMARY OF THE INVENTION 
     A medical instrument in the form of an articulating curette for decorticating and/or preparing a vertebral endplate of a vertebra of a spine, particularly, but not necessarily, during minimally invasive spine surgery, micro invasive spine surgery or similar spine procedure, has a handle, a controller connected to the handle, two opposing arms extending from the controller and defining two arm ends distal to the controller, a control shaft defining a distal control shaft end and a proximal control shaft end and disposed between the two opposing arms, the control shaft proximal end operably coupled to the controller for longitudinally axial movement of the control shaft by the controller relative to the two opposing arms, a decorticating head having a blade for decorticating and/or preparing vertebral endplates of vertebrae and pivotally connected to the two arm ends of the two opposing arms for articulation thereof relative to the two opposing arms, and a pivot mechanism situated on and between the decorticating head and the control shaft distal end for providing controlled articulation of the decorticating head through longitudinally axial movement of the control shaft. 
     Rotational movement of the controller moves the control shaft axially relative to the two opposing arms to articulate the decorticating head relative to the two opposing arms and the control shaft, wherein the decorticating head pivots from and between 0° and 90° positions relative to the longitudinal axis of the control shaft whereby the decorticating head sweeps along an arc beyond a diameter or perimeter of the cannula after the decorticating head has been extended from the cannula. Rotational movement of the controller in a first direction moves the control shaft in a first longitudinally axial direction to sweep the decorticating head from the 0° position to the 90° position, while rotational movement of the controller in a second direction moves the control shaft in a second longitudinally axial direction to sweep the decorticating head from the 90° position to the 0° position. Prepping the vertebral endplate by the decorticating head occurs during movement or swipes of the decorticating head at any position from 0° to 90°. 
     In one form, the pivot mechanism includes two opposing slots in a bifurcated proximal end of the decorticating head, the bifurcated proximal end pivotally connected to the two arm ends of the two opposing arms, and a pivot pin on the distal control shaft end that extends into the two opposing slots. The opposing slots are situated at an angle relative to the longitudinal axis of the two opposing arms and control shaft. Longitudinal axially movement of the control shaft moves the pivot pin within the opposing slots to provide the arcuate motion of the decorticating head. 
     In one form, the decorticating head has an opening for collecting shaved vertebral endplate material from the vertebra. 
     The articulating curette is sized for use, preferably, but not necessarily, with a cannula. 
     Further aspects of the present invention will become apparent from consideration of the drawings and the following description of a form of the invention. A person skilled in the art will realize that other forms of the invention are possible and that the details of the invention can be modified in a number of respects without departing from the inventive concept. The following drawings and description are to be regarded as illustrative in nature and not restrictive. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention and its features will be better understood by reference to the accompanying drawings, wherein: 
         FIG.  1    is a view of a medical instrument, fashioned in accordance with the present principles, formed as an articulating curette for decorticating vertebral endplates from a vertebra of a spine during spine surgery using a cannula; 
         FIG.  2    is an enlarged view of a distal end of the articulating curette of  FIG.  1    with a decorticating head thereof in an axially 0° position; 
         FIG.  3    is an enlarged view of the decorticating head of the articulating curette of  FIG.  1    with the decorticating head in an axially straight or 0° position; 
         FIG.  4    is another enlarged view of the decorticating head of the articulating curette of  FIG.  1    with the decorticating head in an axially angled position between 0° and 90°; 
         FIG.  5    is another enlarged view of the decorticating head of the articulating curette of  FIG.  1    with the decorticating head in another axially angled position between 0° and 90°; 
         FIG.  6    is another enlarged view the decorticating head of the articulating curette of  FIG.  1    with the decorticating head in an axially angled 90° position; 
         FIG.  7    is an enlarged side view of the decorticating head of the articulating curette of  FIG.  1    with the decorticating head in the axially straight or 0° position; 
         FIG.  8    is another enlarged side view of the decorticating head of the articulating curette of  FIG.  1    with the decorticating head in an axially angled position between 0° and 90°; 
         FIG.  9    is another enlarged side view of the decorticating head of the articulating curette of  FIG.  1    with the decorticating head in the axially angled 90° position; 
         FIG.  10    is an enlarged end view of only the decorticating head of the articulating curette of  FIG.  1    in the axially 0° position; 
         FIG.  11    is a view of the decorticating head of the articulating curette of  FIG.  1    emerging from a cannula with the decorticating head in the axially 0° position; 
         FIG.  12    is another view of the decorticating head of the articulating curette of  FIG.  1    emerging from the cannula with the decorticating head in an axially angled position between 0° and 90°; 
         FIG.  13    is another view of the decorticating head of the articulating curette of  FIG.  1    emerging from the cannula with the decorticating head in the axially angled 90° position; and 
         FIG.  14    is another view of the decorticating head of the articulating curette of  FIG.  1    fully extended from the cannula with the decorticating head in the axially angled 90° position. 
     
    
    
     For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications in the described embodiment, and any further applications of the principles of the invention as described herein are contemplated as would normally occur to one skilled in the art to which the invention relates. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIG.  1   , there is shown a medical instrument in the form of an articulating curette, generally designated  10 , for decorticating and/or preparing (collectively, decorticating) vertebral endplates (not shown) of vertebrae (not shown) of a spine (not shown) during a surgical spine procedure, particularly, but not necessarily, in minimally invasive spine surgery, micro spine surgery, or the like (surgical spine procedure) with the use of a cannula, endoscope, or the like (collectively, cannula). The articulating curette  10  is made from one or more surgical grade materials, and overall defines a proximal end  60  and a distal end  61 . 
     The articulating curette  10  has a handle  12  defining a proximal end  62  and a distal end  63 , a controller  13  coupled to the distal end  63  of the handle  12 , a shaft assembly  14  defining a proximal end  64  connected to a distal end  80  of the controller  13  opposite the handle  12 , a decorticating head or end  18  at a distal end  65  of the shaft assembly  14  with the decorticating head  18  having a decorticating, shaving, or blade structure  21 , and a pivot mechanism  31  pivotally coupling the decorticating head  18  with the distal end  65  of the shaft assembly  14  for articulating the decorticating head  18  about and relative to the distal end  65  of the shaft assembly  14 . The decorticating head  18  defines a proximal end  66  and a distal end  67 . The shaft assembly  14  has first and second opposing arms  15   a ,  15   b  and a control shaft  16  situated between the first and second opposing arms  15   a ,  15   b , the nomenclature first and second being arbitrary here and throughout unless specifically indicated otherwise. 
     As best depicted in  FIGS.  3 - 6 ,  7 - 9 , and  11 - 14   , once the decorticating head  18  extends beyond the cannula  50 , the decorticating head  18  and therefore the decorticating structure  21 , is able to sweep an arc of 0° to 90° from a longitudinal axis LA of the shaft assembly  14  and beyond the diameter or perimeter of the cannula  50 . Decorticating a vertebral endplate by the decorticating head  18  can occur at any position from 0° to 90°, but is typically accomplished during a sweep of the decorticating head  18  from the 0° position to the 90° position. 
     Turning to  FIG.  2   , the distal end  65  of the shaft assembly  14  with the decorticating head  18  and pivot mechanism  31  is specifically shown. The decorticating head  18  has a body  19  with the decorticating structure  21  situated generally transverse to the longitudinal axis LA of the shaft assembly  14  and essentially on a distal end  67  of the body  19 . The decorticating structure  21  may be slightly curved and includes a first blade  78  on a first underside of the decorticating structure  21 , and a second blade  79  on a second underside of the decorticating structure  21 . The first and second blades  78 ,  79  are configured to scrape against the vertebral endplate during a swipe from 0° to 90°. An opening  20  is adjacent the first and second blades  78 ,  79  that can collect shaven vertebral endplate material and/or allow shaven (decorticated) vertebral endplate material to pass therethrough for collection by another medical instrument (not shown). The body  19  has a bifurcated proximal end  66  that is pivotally connected to the arms  15   a ,  15   b . Particularly, the decorticating head  18  includes a neck  22  that splits into a first leg  23  and a second leg  24  which are opposite each other and defines an opening  36  between the first and second leg  23 ,  24 . The first leg  23  is pivotally attached to a distal, curved end  27  of the second arm  15   b , while the second leg  24  is pivotally attached to a distal, curved end  29  of the first arm  15   a , each by a pivot pin  27  extending through the first leg  23 , the end  27 , the second leg  24 , and the end  29 . A first boss  25  is situated in the distal end of the first leg  23  adjacent the neck  22 , while a second boss  26  is situated in the distal end of the second leg  24  adjacent the neck  22 . A first slot  32  is provided in the first leg  23  that extends at an angle from the first boss  25  relative to the longitudinal axis LA of the shaft assembly  14  towards the proximal end  64  of the shaft assembly  14 . A second slot  33  is provided in the second leg  24  that extends at an angle from the second boss  26  relative to the longitudinal axis LA of the shaft assembly  14  toward the proximal end  64  of the shaft assembly  14 . The angle of the first and second slots  32 ,  33  are the same. 
     The control shaft  16  has a stem  28  on its distal end that is received in the opening  36  between the first and second legs  23 ,  24 . The distal end of the stem  28  has a flange  37  with a pin  30 . The flange  37  is situated in the opening  36 , while the pin  30  extends into the first and second slots  32 ,  33 . Longitudinally axial movement of the control shaft  16  controls articulation of the decorticating head  18  about the first and second arms  15   a ,  15   b . In  FIG.  2   , the control shaft  16  is in its axially most forward or furthermost position wherein the shaving head is in the 0° position (co-axial with the longitudinal axis LA of the shaft assembly  14 ). The pin  30  is at its travel end within the first and second slots  32 ,  33  at the first and second bosses  25 ,  26 . 
       FIGS.  3 - 6    depict a sequence of articulation of the decorticating head  18  from its 0° position to its 90° position. In  FIG.  3   , the control shaft  16 , through manipulation the controller  13 , is in its furthermost axial position wherein the decorticating head  18  is in the 0° position. In  FIG.  4   , the control shaft  16 , through manipulation of the controller  13 , has been axially moved rearward (towards the handle  12  or the proximal end of the medical instrument  10 ). Since the decorticating head  18  is fixed in position relative to the first and second arms  15   a ,  15   b , axially rearward movement of the control shaft  16 , axially moves the stem  28  and thus the pin  30  rearward. The pin  30  thus pulls against the decorticating head  18  via the first and second slots  32 ,  33  such that the decorticating head  18  is caused to articulate (pivot) downward.  FIG.  4    depicts the decorticating head  18  at an angle α relative to the 0° position. Further longitudinally axial movement of the control shaft  16  towards the handle  12  further causes the pin  30  to pull against the first and second slots  32 ,  33  to further articulate the decorticating head  18  downward. This is depicted in  FIG.  5    where the decorticating head  18  has now been articulated into an angle β relative to the 0° position, with angle β greater than angle α. Still further, longitudinally axial movement of the control shaft  16  towards the handle  12  further causes the pin  30  to pull against the first and second slots  32 ,  33  to further articulate the decorticating head  18  downward. This is depicted in  FIG.  6    where the decorticating head  18  has now been articulated into a final angular position of 90°. At this point, vertebral endplate bone material has been removed (decorticated) from the vertebral endplate, with the removed vertebral endplate bone material accumulating in the opening  20  of the decorticating head  18 . Moving the control shaft  16  in the opposite longitudinally axial direction swings the decorticating head  18  from the 90° position to the 0° position. 
       FIGS.  7 - 9    show the articulation (pivoting) of the decorticating head  18  from the 0° position to the 90° position with an intermediate angular position of angle Δ. The decorticating head  18 , pivot mechanism  31 , and distal end of the control shaft  16  are shown with the first arm  15   b  removed. 
       FIG.  10    depicts a perspective view of the distal end  65  of the shaft assembly  14  with the end in sectional. The control shaft  16  is slidingly connected to a main shaft  15  by a dovetail configuration that extends from the controller  13 . The main shaft  15  has a dovetail groove  40  extending along the longitudinal length of the main shaft  15 . The control shaft  16  has a dovetail flange  38  that is received in the dovetail groove  40 . This provides a positive engagement of the control shaft  16  to the main shaft  15 . 
       FIGS.  11 - 14    show the decorticating head  18  emerging from the cannula  50 , such as during a minimally or micro invasive spine procedure. The cannula  50  has a longitudinal bore  52  and a slanted distal end  51 . Movement of the decorticating head  18  through the cannula  50  is designated by the double-headed arrow adjacent the cannula/shaving head.  FIG.  11    shows the decorticating head  18  beginning to emerge from the end  51  of the cannula  50 . The decorticating head  18  is at the 0° position.  FIG.  12    shows the decorticating head  18  emerged from the end  51  of the cannula  50  and positioned at the angle α.  FIG.  13    shows the decorticating head  18  positioned at the 90° angle.  FIG.  14    shows the decorticating head  18  at the 90° position and fully extended from the end  51  of the cannula  50 . Retraction of the decorticating head  18  into the cannula  50  is by the reverse process. 
     One method of removing vertebral endplate material from a vertebral endplate of a vertebra of a spine (decorticating a vertebral endplate) includes positioning the cannula  50  adjacent a vertebral disc space (not shown) or vertebral endplate (not shown) of a spine (not shown); inserting the articulating curette  10  into the cannula  50 ; manipulating the controller  13  to longitudinally axially move the decorticating head  18  into position as depicted in Figs. 11 - 14 ; removing vertebral endplate material or decorticating a vertebral endplate from the vertebral endplate (not shown) of the vertebra (not shown) of the spine (not shown); retracting the decorticating head  18  into the cannula; and removing the articulating curette  10  from the cannula  50 . 
     While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only a preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected. It should be understood that while the use of words such as preferable, preferably, preferred or more preferred utilized in the description above indicate that the feature so described may be more desirable, it nonetheless may not be necessary and embodiments lacking the same may be contemplated as within the scope of the invention.