Patent Publication Number: US-2020289292-A1

Title: Anatomic Shell 2-in-1 Window Trial

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of the filing date of U.S. Provisional Patent Application No. 62/817,209, filed Mar. 12, 2019, the disclosure of which is hereby incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     Joint arthroplasty procedures involve the replacement of a natural joint surface with an artificial joint surface. This generally involves removing a certain amount of native bone and attaching the artificial prosthesis to the resected bone. As joint arthroplasty procedures are often performed on diseased or damaged joints, it is common that the underlying bone to which the joint prosthesis is attached is also diseased or damaged in a way that can affect the structural support needed for proper functioning of the artificial joint prosthesis and for long-term fixation thereof. 
     For example, fixation means, such as bone screws, may be deployed to secure prosthetic components to bone. However, the underlying bone may be weakened in certain areas due to damage or disease, such as osteolysis and the like, such that the bone is not adequate to support the fixation means. Visual inspection can help distinguish regions of healthy bone from those of unhealthy bone so that the operator can utilize the healthy bone to secure the prosthesis thereto. However, currently existing surgical instruments often obscure the underlying bone making it difficult to determine whether or not the means for fixing the prosthesis to the bone has adequate support prior to the deployment of the same. Moreover, such surgical instruments are often configured for one bone or another (i.e., right or left) resulting in a cluttering of the operating theater and a high demand on sterilization resources. Thus, further improvements are desirable. 
     BRIEF SUMMARY OF THE INVENTION 
     In one aspect of the present disclosure, an arthroplasty system includes a first component that includes a convex side configured to engage one of an acetabulum and glenoid cavity, a concave side opposite the convex side, a first component periphery that defines an outer perimeter of the first component and is defined by a convergence of the convex and concave sides, and a tool opening that extends through the first component from the concave side to the convex side and is configured to receive at least one of a bone screw or drill bit. The tool opening includes a center point defined by an axis extending along a length of the tool opening. The system also includes a second component separate from the first component. The second component includes a bone facing side, a visualization side opposite the bone facing side, and a second component periphery that defines an outer perimeter of the second component and that substantially corresponds to the first component periphery. The second component also has first and second support members and a first visualization member. The first and second support members each include a length extending in a direction transverse to an axis that extends through the bone facing and visualization sides within the second component periphery. The first and second support members define a viewing window therebetween that extends through the second component from the visualization side to the bone facing side. The first visualization member extends between the first and second support members and across the viewing window. The first visualization member includes a position relative to the second component periphery that corresponds with a position of the center point of the tool opening relative to the first component periphery. 
     Additionally, the first component may be a drill guide. Alternatively, the first component may be a prosthesis that includes an articular surface at the concave side. The concave side may further include a rim extending at least partially about the concave articular surface. The opening of the first component may extend through the rim and the convex surface. The first support member may partially include the second component periphery. The first and second support members may be arcuate. Also, the first visualization member may be elongate and may extend along a straight longitudinal axis that extends from the first support member to the second support member. The position of the center point of the tool opening may be intersected by the longitudinal axis of the first visualization member when the first component is overlaid with the second component. 
     Continuing with this aspect, the system may further include a second visualization member adjacent the first visualization member. Also, the system may further include a third component that has a tool opening extending therethrough from a convex side to a concave side thereof. The second visualization member may correspond to the tool opening of the third component where the first component may be configured for engagement with a right acetabulum or glenoid cavity and the third component may be configured for engagement with a left acetabulum or glenoid cavity. 
     In another aspect of the present disclosure, a trial template for visualizing the placement of a bone screw includes a bone facing side, a visualization side opposite the bone facing side, a trial periphery defining an outer perimeter of the trial, and first and second support members positioned within the trial periphery. The first and second support members each have a length that extends in a direction transverse to an axis that extends through the bone facing and visualization sides. The first and second support members define a viewing window therebetween that extends through the second component from the visualization side to the bone facing side. The trial template also includes a visualization member that extends between the first and second support members and across the viewing window. The visualization member has a position within the second component periphery that corresponds with a desired bone screw location in a bone. 
     Additionally, the trial template may include a template portion that defines the trial periphery. Also, the trial periphery may be rounded. The first support member may include a portion of the trial periphery, and the second support member may be offset radially inwardly from the first support member. The visualization member may be one of a plurality of visualization members that each extend from the first support member to the second support member and across the viewing window. The visualization members may be spaced at predetermined intervals such that each visualization member corresponds to a desired bone screw location in the bone. 
     In a further aspect of the present disclosure, a method of implanting a prosthesis into a bone cavity includes placing a template over the bone cavity such that a visualization member thereof is positioned over a first location. The visualization member may extend between first and second support members and across a viewing window defined by first and second support members. The method also includes assessing a quality of bone at the first location by looking through the viewing window adjacent the visualization member, removing the template from the bone cavity, inserting a prosthesis into the bone cavity, and inserting a bone screw into the bone at the first location and through a screw opening of the prosthesis. 
     Additionally, the bone cavity may be one of an acetabulum or glenoid. Also, the placing step may include inserting a convex portion of the template into the cavity such that the convex portion abuts the bone within the bone cavity. Further, the placing step may include sliding the template over an elongate shaft extending from the bone. The removing step may also include sliding the template off of the elongate shaft. The method may also include reaming the bone cavity prior to the placing step, and also marking the bone relative to a reference mark on the template. Inserting the prosthesis into the bone cavity may include aligning a reference mark on the prosthesis with the marking on the bone. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings in which: 
         FIG. 1A  is a side elevational view of a prosthesis according to an embodiment of the present disclosure. 
         FIG. 1B  is a front elevational view of the prosthesis of  FIG. 1A . 
         FIG. 1C  is a rear elevational view of the prosthesis of  FIG. 1A . 
         FIG. 2A  is a front elevational view of a template according to an embodiment of the present disclosure. 
         FIG. 2B  is a rear elevational view of the template of  FIG. 2A . 
         FIG. 2C  is a side elevational view of the template of  FIG. 2A . 
         FIG. 2D  is a top view of the template of  FIG. 2A . 
     
    
    
     DETAILED DESCRIPTION 
     When referring to specific directions in the following discussion of certain implantable devices, it should be understood that such directions are described with regard to the implantable device&#39;s orientation and position during exemplary application to the human body. Thus, as used herein, the term “proximal” means close to the heart and the term “distal” means more distant from the heart. The term “inferior” means toward the feet and the term “superior” means toward the head. The term “anterior” means toward the front of the body or the face, and the term “posterior” means toward the back of the body. The term “medial” means toward the midline of the body, and the term “lateral” means away from the midline of the body. Also, as used herein, the terms “about,” “generally” and “substantially” are intended to mean that slight deviations from absolute are included within the scope of the term so modified 
       FIGS. 1A-1C  depict a first component or shell prosthesis  10  according to an embodiment of the present disclosure. In the particular embodiment depicted, shell prosthesis  10  is an acetabular shell of an acetabular cup prosthesis which would also include a polymer insert (not shown). However, it should be understood that other forms of shell prostheses, such as those configured for a glenoid cavity, may be utilized without departing from the present invention. Prosthesis  10  generally includes a convex side or bone contact side  20  and a concave side or articular side  30 . Convex side  20  includes a convex surface or bone contact surface  22 . Bone contact surface  22  may include a structure to promote bone ingrowth when cup prosthesis is press-fit into a cavity of a bone. 
     Concave side  30  of prosthesis includes a shell opening  34  which is configured to receive the polymer insert for articulation with a corresponding prosthesis, such as a femoral or humeral prosthesis. Shell opening  34  is defined by a concave inner surface  36 . In the particular embodiment depicted a rim  32  extends about shell opening  34  of concave side  30 . The convergence of concave side  30  and convex side  20  defines a periphery of prosthesis which in turn forms a perimeter  12  of both concave side  30  and convex side  20 . Such perimeter  12  is at least partially defined by rim. Rim  32  has a tapering width in its extension both clockwise and counterclockwise about shell opening  34 . Such width is defined between perimeter  12  and shell opening  34 . 
     Prosthesis  10  also includes a plurality of tool openings  38   a - e  that extend entirely through prosthesis  10  from rim  32  to bone contact surface  22 . In addition, tool openings  39  extend entirely through prosthesis  10  from concave inner surface  36  to bone contact surface  22 . Such tool openings  38 ,  39  are configured to receive a drill bit so as form a pilot hole in the bone, and a bone screw so as to securely fix prosthesis  10  to underlying bone. 
       FIGS. 2A-2D  depict a second component or window/trial template  100  according to an embodiment of the present disclosure. Trial template  100  generally includes a convex side or bone facing side  110  and concave or visualization side  120 . Convex and concave sides  110 ,  120  converge at a template periphery that defines a perimeter  102  of convex and concave sides  110 ,  120 . Such perimeter  102  corresponds to perimeter  12  of prosthesis  10  such that template  100  has virtually the same geometry and peripheral dimensions as that of prosthesis  10 . 
     Trial template  100  also includes a first support member  122 , second support member  126 , and convex portion or distal portion  110 . First and second support members  122 ,  126  are connected such that they form a proximal portion  119  of template  100 , and distal portion  118  extends distally from first and second support members  122 ,  126 . First and second support members  122 ,  126  are both circular such that they collectively define perimeter  102  which is correspondingly circular. First support member  122  has a cross-sectional dimension smaller than that of second support member  126 . First support member  122  is positioned within second support member  126  in an offset relationship such that first and second support members  122 ,  126  are not concentric with each other. In this regard, first and second support members  122 ,  126  define a crescent-shaped viewing window or first viewing window  108   a  that extends between portions of first and second support members  122 ,  126 . In the embodiment depicted, first viewing window  108   a  is located at a superior end or first end of template  100  while at an inferior end or second end of template  100  first and second support members  122 ,  126  converge into each other such that first viewing window  108   a  tapers to an end at their interface. First and second support members  122 ,  126  are both hollow such that a second viewing window  108   b,  which is defined by an inner surface of first support member  122 , extends entirely through template  100  in a proximal-distal direction. Similarly, first viewing window  108   a  extends entirely through template  100 . 
     First and/or second support members  122 ,  126  include alignment markings  104   a - b  that can be aligned with markings on the bone, particular anatomy, or general directions such as superior and inferior in order to help set the alignment/rotational orientation of trial template  100  relative to the bone. As shown, in  FIG. 2A , a first alignment marking  104   a  is configured to help properly orient template in a first bone, such as a right acetabulum or glenoid, and a second alignment marking  104   b  is configured to help properly orient template  100  in a second bone, such as a left acetabulum or glenoid. 
     Trial template  100  also includes a plurality of visualization members  124 ,  125 , as best shown in  FIGS. 2A and 2B . Visualization members  124 ,  125  are depicted as elongate beams that extend between first and second support member  122 ,  126  and across first viewing window  108   a.  Visualization members  124 ,  125  are located within the periphery of trial template  100  such that they each correspond to a tool opening in a prosthesis, such as tool openings  38   a - e.  More particularly, trial template includes a first set of visualization members  124   a - e  that are located relative to first alignment marking  104   a  such that the first set of visualization members  124   a - e  are configured for use relative to a right variant of a bone, while a second set of visualization members  125   a - e  are located relative to second alignment marking  104   b  such that they are configured for use relative to a left variant of a bone. In other words, when first alignment marking  104   a  is aligned with a marking or particular anatomy of a right variant of bone, the first set of visualization members  124   a - e  are in a predetermined position for that bone. Second visualization members  125   a - e  and alignment marking  104   b  are similarly configured for a left variant of bone. In this regard, template  100  is universal to left and right variants of a bone and thus minimizes the total number of instruments present in an operating theater. Indicia  106  on trial member helps an operator determine which visualization members  124 ,  125  are for which bone. 
     Also, in the particular embodiment depicted, each of the first and second sets of visualization members  124   a - e,    125   a - e  includes five visualization members which each correspond to a respective tool opening in a prosthesis. However, it should be understood that more or less visualization members  124 ,  125  may be utilized depending on the tool openings of the prosthesis that are desirable for visualization via trial template  100 . In the depicted embodiment, it is desired to visualize tool openings  38   a - e  of prosthesis  10 . Thus, second set of visualization members  125   a - e  are arranged to correspond to tool openings  38   a - e  of prosthesis as prosthesis  10  is configured for a left acetabulum as are visualization members  125   a - e.  However, first set of visualization members  124   a - e  correspond to tool openings of a second prosthesis or third component (not shown) that is configured for a right acetabulum and is basically a mirror image of prosthesis  10 . Such correspondence means that, where template  100  is overlaid onto a corresponding prosthesis, such as prosthesis  10 , visualization members  124   a - e  or  125   a - e,  depending on the prosthesis, would dissect its corresponding tool opening such that each visualization member  124   a - e  or  125   a - e  intersects the center point of the respective tool opening. The center point of each tool opening, such as openings  38   a - e,  is coincident with a central axis of such opening. So, while not every tool opening extends through its prosthesis in the same orientation (i.e., parallel with each other), such tool openings nonetheless have a center point at the proximal side or concave side of the prosthesis. For example, visualization members  125   a - e  are configured to align with the center points of tool openings  38   a - e  at this proximal side  30  of prosthesis  10 , rather than the distal or convex side  20  of prosthesis. Stated differently, tool openings  38   a - e  may extend through prosthesis  10  at different angles such that a center point of each tool opening  38   a - e  at proximal side  30  of prosthesis  10  is offset relative to that of distal side  20 . Visualization members  125   a - e  are configured to align with the center point at proximal side  30  of prosthesis  10 . Visualization members  124   a - e  are similarly configured to a second prosthesis. Thus, each visualization member  124 ,  125  is spaced at predetermined intervals relative to each other with the viewing window  108   a  surrounding each visualization member  124 ,  125 . The low profile nature of visualization members  124 ,  125  provides visual clearance for an operator to inspect the underlying bone through window  108   a  directly underneath such visualization members  124 ,  125 . This allows the operator to determine the health of the bone at the precise location through which a bone screw will be driven. In addition, it allows the operator to inspect the seating of the distal and proximal portions  118 ,  119  of template  100  relative to the bone to determine if further refinements of the resected bone surfaces are needed to appropriately receive prosthesis  10 . 
     Distal portion  118  of template has a convex exterior such that it has a convex curvature similar to that of bone contact surface  22  of prosthesis  10 . However, distal portion  118  has a concave interior. Distal portion  118  is comprised of a plurality of arm members  114  that extend from the proximal portion  119  of template  100  and curve inwardly to a distal apex  111  where arm members  114  intersect. In the embodiment depicted, there are three arm members  114   a - c  which define a cylindrical opening  116  at the distal apex  111 . It should be understood that more or less arm members  114  may be utilized. However, three arm members  114   a - c  is preferable as it allows for three points of contact for stability while simultaneously maximizing the viewing space around such arm members  114   a - c  to visualize underlying bone. Cylindrical opening  116  is configured to receive a guide shaft (not shown) which may be pre-positioned within the bone so as to guide template  100  to a predetermined position relative to the bone. However, in some embodiments, cylindrical opening  116  may be absent. 
     Prosthesis  10  and trial template  100  may be included in a kit. Such kit may also include other prostheses and trial templates of different sizes. Moreover, the kit can include a third component or second shell prosthesis (not shown). Second prosthesis is similar to first shell prosthesis  10  with the difference being that it is configured for implantation in an opposite sided bone. In this regard, second prosthesis is a mirror image of first prosthesis  10 . Thus, the kit may include first prosthesis  10 , the second prosthesis, and trial template  100  where trial template  100  corresponds to both the first and second prostheses and where the first and second prostheses are configured for opposing variants of a bone. In addition, multiples of this grouping (i.e., first and second prostheses and trial template  100 ) may be provided with differing sizes to accommodate patients of all sizes. Thus, it should be clear that the more sizes that are provided in the kit, the less clutter trial template  100  minimizes relative to a trial that is not universal. However, it is contemplated that a trial template, similar to template  100 , may be provided that is configured only for one variant of bone (i.e., right or left) without departing from the scope of this disclosure. In this regard, the template would not include members  124   a - e  or  125   a - e  creating more space for visualization. 
     In a method of using trial template  100 , an operator gains access to a bone cavity that comprises a joint, such as a hip or shoulder joint. The acetabulum, or glenoid, is prepared, such as by using a reamer to resect the bone for reception of prosthesis  10 . Once the bone is prepared and ready for trialing, trial template  100  is placed into the bone cavity such that arm members  114   a - c  contact the underlying bone. Such placement may be aided with a guide rod extending from the acetabulum. In this regard, trial template  100  may be placed over the guide rod such that the guide rod extends through cylindrical opening  116 . Trial template  100  is rotated into an appropriate orientation relative to the bone using alignment markings  104   a  or  104   b,  depending on the bone it is being inserted into. In this regard, where trial template  100  is placed into a left acetabulum, second alignment marking  104   b  may be oriented so that such marking points in a superior direction or is aligned with a marking previously made in the bone, for example. Alternatively, where trial template  100  is placed into a right acetabulum, first alignment marking  104   a  may be oriented in a similar manner 
     Once the trial template  100  is appropriately oriented, operator views the underlying bone via viewing windows  108   a - b  to assess the bone quality beneath template  100  and to assess the fit of trial  100  within the bone. Moreover, when viewing the underlying bone through first window  108   a,  the operator can visualize the locations in which bone screws will be inserted by looking at visualization members  124  or  125  relative to the bone. The center point of their insertion lies along the visualization members  124  or  125 . Thus, the operator can assess the bone quality around visualization members  124  or  125  to determine the bone quality at the insertion locations of the bone screws to determine if remedial measures should be taken. Once trial  100  is removed from the bone, prosthesis  10  is inserted into the bone at the same orientation as that of trial template  100  so that tool openings  38   a - e  are positioned at the previously visualized screw insertion regions. Pilot holes may then be drilled into the bone through prosthesis  10  and bone screws inserted therein in order to fix prosthesis  10  to the bone. 
     As described above, trial template  100  includes visualization members  124 ,  125  that correspond to tool openings of alternative prostheses. However, visualization members  124 ,  125  may also correspond to tool openings of one or more drill guides. In other words, in some embodiments, no pilot holes are pre-drilled into bone, or, in other embodiments, a pilot hole is drilled through prosthesis  10  after such prosthesis  10  has been press-fit or otherwise temporarily secured to the underlying bone. In either circumstance, the prosthesis  10  itself at least partially acts as a drill guide. However, in other circumstances, a drill guide with multiple drill openings may be used separately to drill pilot holes at predetermined locations as dictated by the structure of the guide before prosthesis  10  is implanted and secured to the bone. An exemplary drill guide can be found in U.S. Pat. No. 5,769,856, the disclosure of which is incorporated herein by reference in its entirety. In this regard, template  100  may be used similarly to visualize the underlying bone before the drill guide is used to drill pilot holes. Thus, where a drill guide is utilized, visualization members  124  or  125  would correspond to both the tool openings  38  of the prosthesis as well as tool openings of the drill guide. 
     In addition, while trial template  100  was described as including visualization members  124   a - e  or  125   a - e  that correspond to tool openings  38   a - e,  but not tool openings  39 , another embodiment of trial template  100  can include further visualization members (not shown) to correspond to tool openings  39 . In this regard, visualization members may extend between an arm member  114   a - c  of distal portion  118  of trial  100  and either first or second support members  122 ,  126  of proximal portion  119  so as to indicate a line along which bone screws may be inserted into the bone. This would allow an operator to utilize second visualization opening  108   b  to inspect the bone through which bone screws extending through tool openings  39  would be inserted. 
     Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.