Abstract:
An interlocking interface retains a screw head in a socket to prevent migration of the screw head out of the socket, or to lock the screw head in the socket. The interlocking interface may retain or lock the screw at various polyaxial angles with respect to the socket. The screw head includes external corrugations. The socket includes an internal corrugated structure which interlocks with the external corrugations of the screw head when the screw is at various polyaxial angles with respect to the socket.

Description:
BACKGROUND 
       [0001]    The present disclosure relates to retention interfaces in medical devices, such as to prevent a screw from migrating, unthreading, “backing out” and the like. This disclosure also relates to interlocking interfaces, such as screw head and device holes, such as bone plate holes. The principles herein are applicable wherever it is desired to prevent a part from migrating relative to a corresponding socket and/or wherever it is desired to lock a part to a socket. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0002]    While examples of the present technology have been shown and described in detail below, it will be clear to the person skilled in the art that variations, changes and modifications may be made without departing from its scope. As such, that which is set forth in the following description and accompanying drawings is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined by the following claims, along with the full range of equivalents to which such claims are entitled. 
           [0003]    In the following Detailed Description, various features are grouped together in several examples for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that examples of the technology require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed example. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate example. 
           [0004]    Identical reference numerals do not necessarily indicate an identical structure. Rather, the same reference numeral may be used to indicate a similar feature or a feature with similar functionality. Not every feature of each example is labeled in every figure in which that example appears, in order to keep the figures clear. Similar reference numbers (e.g., those that are identical except for the first numeral) are used to indicate similar features in different examples. 
           [0005]      FIG. 1  is an isometric view of an interlocking interface between a screw and a socket; 
           [0006]      FIG. 2  is an isometric exploded view of the screw and socket of  FIG. 1 ; 
           [0007]      FIG. 3  is a top view of the screw and socket of  FIG. 1 ; 
           [0008]      FIG. 4A  is another top view of the screw and socket of  FIG. 1 ;  FIG. 4B  is a front cross-sectional view of the screw and socket of  FIG. 1 , taken along section line  4 B- 4 B of  FIG. 4A , a range of positions of the screw relative to the socket is shown by dashed lines; and  FIG. 4C  is a front cross-sectional view of the socket of  FIG. 1 , also taken along section line  4 B- 4 B of  FIG. 4A ; 
           [0009]      FIG. 5  is a top view of the socket of  FIG. 1 ; 
           [0010]      FIG. 6  is an isometric view of another socket; 
           [0011]      FIG. 7A  is a top view of the socket of  FIG. 6 ; and  FIG. 7B  is a front cross-sectional view of the socket of  FIG. 6 , taken along section line  7 B- 7 B of  FIG. 7A ; 
           [0012]      FIG. 8  is an isometric cross-sectional view of the socket of  FIG. 6 , taken along section line  7 B- 7 B of  FIG. 7A ; 
           [0013]      FIG. 9  is an isometric view of another interlocking interface between the screw and yet another socket; 
           [0014]      FIG. 10  is an isometric exploded view of the screw and socket of  FIG. 9 ; 
           [0015]      FIG. 11A  is a top view of the screw and socket of  FIG. 9 ; and  FIG. 11B  is a compound front cross-sectional view of the screw and socket of  FIG. 9 , taken along section line  11 B- 11 B of  FIG. 11A , a first position of the screw shown on the left and a second position of the screw shown on the right; 
           [0016]      FIG. 12  is a top view of the socket of  FIG. 9 ; 
           [0017]      FIG. 13  is a sketch of the cross-sectional geometry of the socket of  FIG. 9 ; 
           [0018]      FIG. 14A  is another top view of the socket of  FIG. 9 ; and  FIG. 14B  is a front cross-sectional view of the socket of  FIG. 9 , taken along section line  14 B- 14 B of  FIG. 11A ; 
           [0019]      FIG. 15A  is a top view of yet another socket; and  FIG. 15B  is a front cross-sectional view of the socket of  FIG. 15A , taken along section line  15 B- 15 B of  FIG. 15A ; 
           [0020]      FIG. 16A  is a front view of the screw of  FIG. 1 ;  FIG. 16B  is a top view of the screw of  FIG. 1 ; and  FIG. 16C  is a front cross sectional view of the screw of  FIG. 1 , taken along section line  16 C- 16 C of  FIG. 16B ; 
           [0021]      FIG. 17A  is a top view of yet another socket;  FIG. 17B  is a front cross-sectional view of the socket of  FIG. 17A , taken along section line  17 B- 17 B of  FIG. 17A ; and  FIG. 17C  is an isometric view of a sweep profile of the socket of  FIG. 17A ; and 
           [0022]      FIG. 18A  is a top view of yet another socket; and  FIG. 18B  is an isometric view of the socket of  FIG. 18A . 
       
    
    
     DETAILED DESCRIPTION 
       [0023]    Standard medical planes of reference and descriptive terminology are employed in this specification. A sagittal plane divides a body into right and left portions. A mid-sagittal plane divides the body into bilaterally symmetric right and left halves. A coronal plane divides a body into anterior and posterior portions. A transverse plane divides a body into superior and inferior portions. Anterior means toward the front of the body. Posterior means toward the back of the body. Superior means toward the head. Inferior means toward the feet. Medial means toward the midline of the body. Lateral means away from the midline of the body. Axial means toward a central axis of the body. Abaxial means away from a central axis of the body. Ipsilateral means on the same side of the body. Contralateral means on the opposite side of the body. These descriptive terms may be applied to an animate or inanimate body. 
         [0024]    Referring to  FIGS. 1-5 , a locking interface  10  includes a head  20  and a socket  40 . 
         [0025]    With reference to  FIGS. 1-5  and  16 A- 16 C, the head  20  is an external feature which may be formed on any medical device component, such as a fastener, connector, rod, link, bone-contacting component, articular component, and the like. The head  20  shown in  FIG. 1  is an external feature formed on a proximal end  22  of a fastener  24 . The fastener  24  includes a distal portion  26  which may include bone fixation features, such as external threads, ribs, porous coating, and the like; however, for simplicity, a smooth cylindrical distal portion  26  is shown in  FIGS. 1-2 , and  4 B; a distal portion  26  with an external thread  54  is shown in  FIGS. 16A and 16C . The head  20  may include an instrument connection feature  28 . The instrument connection feature  28  may be an internal or external feature; a hexagonal internal feature is shown in  FIGS. 1-4A  and a hexalobular internal feature is shown in  FIG. 16B . The internal feature may be a slot, a cruciform indentation or Phillips socket, a polygonal indentation, a hexalobular or Torx socket, a circular hole, and the like. Any of these features may be expressed as an external feature as well. The instrument connection feature  28  may be shaped and sized for complementary connection with an instrument (not shown). The connection feature  28  may couple the head  20  to an instrument so that compressive, tensile, torque, and/or other forces may be transmitted between the head  20  and the instrument. The connection may be a slip fit, a line-to-line fit, an interference fit, an interlocking undercut fit, threads, a snap fit, a taper fit, or any other connection. 
         [0026]    Referring to  FIG. 16C , the head  20  may be formed by revolving a profile  56  about a longitudinal axis of revolution  36 , which may also be described as a longitudinal axis  36  of the head  20 . The revolved profile  56  may be formed by one or more lines, curves, or other two-dimensional shapes. The head  20  may be cylindrical, multi-cylindrical, frustoconical, multi-conical, spherical, cylindro-spherical, ovoid, and the like. The head  20  may also have a faceted perimeter. In the example shown in  FIG. 16C , the revolved profile  56  of the head  20  extends at least between a proximal point  58  and a distal point  60  to define an outermost shape of the head  20 . The illustrated profile  56  includes a proximal line segment  62  which is parallel to the axis  36 , and a distal arc segment  68  which is tangent to the line segment  62 . A center point  66  of the arc segment  68  may lie on the axis  36  as shown or may be offset from the axis  36 . When revolved about the axis  36 , arc segment  68  forms a spherical portion of the head  20  by virtue of having center point  66  on the axis  36 . 
         [0027]    The head  20  includes external corrugations  30  which may be described as forming alternating peaks  32  and valleys  34 . The corrugations  30  may be formed in the head  20  so that the peaks  32  lie upon, or follow, the surface of the head. The valleys  34  may also follow the surface of the head at a fixed offset so that there is a constant valley depth. Alternately, the valleys  34  may follow at a variable offset, so that valley depth varies along the head. The peaks  32  and/or valleys  34  may be sharp or blunt. The external corrugations  30  may be intact or uninterrupted throughout their extent along the head  20 . 
         [0028]    The socket  40  is a noncircular hole, such as the rounded rectangular hole illustrated in  FIGS. 1-5 . The socket  40  may have a longitudinal axis  52 . The socket  40  may be formed in any medical device component, such as a plate, washer, rod, link, bone-contacting component, articular component, and the like. The socket  40  may extend completely through a component, or only partially through the component. The socket  40  may be multi-sided; the example of  FIGS. 1-5  has four flat sides  42  and four rounded corners  44 . The socket  40  may include two or more sides in a polygonal arrangement, such as an oval, triangle, rectangle, pentagon, hexagon, heptagon, octagon, and so on. In this specification, a polygon may have sides that deviate from perfectly straight, for example by bulging or bending inward or outward. The corners  44  may be sharp or rounded. In other examples, the socket  40  may have a poly-lobular profile such as a starburst shape with three or more points or corners  44 . The points  44  may be sharp or rounded, and the sides  42  may bulge toward the interior of the socket in these examples. Examples of poly-lobular profile profiles include pentagram, hexalobe, hexagram, and other star-shaped shapes. Another example may be described as a spline. The socket  40  may have a constant cross-sectional geometry over the full depth of the socket  40 , as seen best in  FIG. 4B . Alternatively, the socket  40  may taper or bulge along its length. The socket  40  may have a spherical or partial spherical interior. The socket  40  may twist along its depth. 
         [0029]    The socket  40  includes an internal corrugation  46  which includes alternating peaks  48  and valleys  50  along the depth of the socket  40 , or a portion thereof. The peaks  48  and/or valleys  50  may be sharp or blunt. The peaks  48  may lie upon, or follow, the interior surface of the socket  40 . The valleys  50  may be described as indentations into the interior surface of the socket  40 , and thus the valleys  50  may also follow the interior surface of the socket  40 , albeit offset below the interior surface. The valleys  50  may follow the interior surface exactly with a constant offset, or generally, with a variable offset. The internal corrugation  46  may be intact, or uninterrupted, throughout its extent so that all of the peaks  48  and valleys  50  are intact. This configuration may reduce socket stresses compared to designs with interrupted threads or other discrete protrusions in the socket. 
         [0030]    The internal corrugations  46  may be formed by a single indentation, or valley  50 , which winds around the socket  40  while progressing longitudinally within the socket  40 . This arrangement is best seen in  FIG. 2 . More than one indentation may be present. Additional indentations may wind around the socket  40  with the single indentation. The longitudinal progression per circuit around the socket  40  may be constant or variable. 
         [0031]    In use, the head  20  may be inserted into the socket  40  with the axes  36 ,  52  aligned or coaxial. This arrangement is shown in  FIGS. 1-2  and in  FIG. 4B  in solid lines. The external corrugations  30  of the head  20  may engage with the internal corrugation feature  46  of the socket  40  so that the peaks  32  rest in the valleys  50  and the peaks  48  rest in the valleys  34 . This engagement may resemble a traditional threaded engagement. However, the incongruent shapes of the head  20  and socket  40  provide alternating zones of contact and clearance between the head  20  and the socket  40 , as can be seen best in  FIG. 3  with reference to  FIG. 5 . Contact occurs between the sides  42  and the head  20 , and clearance occurs between the corners  44  and the head  20 . 
         [0032]    In another method of use, the head  20  may be inserted into the socket  40  with the axes  36 ,  52  misaligned. The axes  36 ,  52  may be intentionally or unintentionally misaligned. Two examples of this arrangement are shown in  FIG. 4B  in dashed lines. The external corrugations  30  of the head  20  may engage with the internal corrugation feature  46  of the socket  40  to lock the head  20  at a range of angles with respect to the socket  40 . This arrangement is facilitated by the zones of contact and clearance between the head  20  and the socket  40 , which permit the corrugations  30  to skip over a zone of clearance instead of encountering an interfering peak  48  in the socket. The dashed line representations in  FIG. 4B  show two possible angular orientations of the head  20  with respect to the socket  40  out of a range of possible angular orientations extending in a conical field around the axis  52  of the socket  40 . The locking interconnection between the head  20  and the socket  40  may be described as polyaxial for this reason. 
         [0033]      FIGS. 6-8  show another socket  70  for use with the head  20  in a polyaxial locking interconnection. Socket  70  is another noncircular hole, which may have a longitudinal axis  72 . The socket  70  may be formed in any medical device component, such as a plate, washer, rod, link, bone-contacting component, articular component, and the like. The socket  70  may extend completely through a component, or only partially through the component. The socket  70  may include two or more sides in a polygonal or poly-lobular arrangement. The socket  70  may have six flat sides  74  and six rounded corners  76 , however the corners  76  may be sharp instead. The socket  70  may have a constant cross-sectional geometry over the full depth of the socket  70  as seen best in  FIG. 7B . Alternatively, the socket  70  may taper or bulge along its length. The socket  70  may have a spherical or partial spherical interior. The socket  70  may twist along its depth. 
         [0034]    The socket  70  includes an internal corrugation  78  which includes alternating peaks  80  and valleys  82  along the depth of the socket  70 , or a portion thereof. The peaks  80  and/or valleys  82  may be sharp or blunt. The peaks  80  may lie upon, or follow, the interior surface of the socket  70 . The valleys  82  may be described as indentations into the interior surface of the socket  70 , and thus the valleys  82  may also follow the interior surface of the socket  70 , albeit offset below the interior surface. The valleys  82  may follow the interior surface exactly with a constant offset, or generally, with a variable offset. The internal corrugation  78  may be intact, or uninterrupted, throughout its extent so that all of the peaks  80  and valleys  82  are intact to minimize stress concentrations. 
         [0035]    The internal corrugations  78  may be formed by a single indentation, or valley  82 , which winds around the socket  70  while progressing longitudinally within the socket  70 . This arrangement is best seen in  FIG. 7B . More than one indentation may be present. Additional indentations may wind around the socket  70  with the single indentation. The longitudinal progression per circuit around the socket  70  may be constant or variable. 
         [0036]    In use, the head  20  may be inserted into the socket  70  with the axes  36 ,  72  aligned or coaxial, or misaligned, as described above for socket  40 . In either arrangement, the external corrugations  30  of the head  20  may engage with the internal corrugation feature  78  of the socket  70  to lock the head  20  at a range of angles with respect to the socket  70 . The incongruent shapes of the head  20  and socket  70  provide alternating zones of contact and clearance between the head  20  and the socket  70 . Contact occurs between the sides  74  and the head  20 , and clearance occurs between the corners  76  and the head  20 . 
         [0037]      FIGS. 9-14B  show another locking interface  90 , which includes the head  20  and yet another socket  100 . Socket  100  is another noncircular hole, which may have a longitudinal axis  102 . The socket  100  may be formed in any medical device component, such as a plate, washer, rod, link, bone-contacting component, articular component, and the like. The socket  100  may extend completely through a component, or only partially through the component. The socket  100  may include two or more sides in a polygonal or poly-lobular arrangement. The socket  100  may have five sides  104  and five rounded corners  106 , however the corners  106  may be sharp instead. The sides  104  may bulge slightly toward the interior of the socket  100 .  FIG. 13  shows a sketch depicting the geometry used to define the five-sided socket  100 . The other sockets disclosed herein may employ similar sketches. The socket  100  may have a constant cross-sectional geometry over the full depth of the socket  100 . Alternatively, the socket  100  may taper ( FIGS. 11B and 14B ) or bulge along its length. The socket  100  may have a spherical or partial spherical interior. The socket  100  may twist along its depth. 
         [0038]    The socket  100  includes an internal corrugation  112  which includes alternating peaks  108  and valleys  110  along the depth of the socket  100 , or a portion thereof. The peaks  108  and/or valleys  110  may be sharp or blunt. The peaks  108  may lie upon, or follow, the interior surface of the socket  100 . The valleys  110  may be described as indentations into the interior surface of the socket  100 , and thus the valleys  110  may also follow the interior surface of the socket  100 , albeit offset below the interior surface. The valleys  110  may follow the interior surface exactly with a constant offset, or generally, with a variable offset. The internal corrugation  112  may be intact, or uninterrupted, throughout its extent so that all of the peaks  108  and valleys  110  are intact. 
         [0039]    The internal corrugations  112  may be formed by a series of indentations, or valleys  110 , which are patterned longitudinally within the socket  100 . This arrangement is best seen in  FIG. 14B . The longitudinal progression per valley  100  along the socket  100  may be constant or variable.  FIG. 14B  includes a sketch of the geometry used to define the internal corrugations  112 , which illustrates a variable longitudinal progression. 
         [0040]    In use, the head  20  may be inserted into the socket  100  with the axes  36 ,  102  aligned or coaxial ( FIG. 11B , left), or misaligned ( FIG. 11B , right), as described above for socket  40 . In either arrangement, the external corrugations  30  of the head  20  may engage with the internal corrugation feature  112  of the socket  100  to lock the head  20  at a range of angles with respect to the socket  100 . The incongruent shapes of the head  20  and socket  100  provide alternating zones of contact and clearance between the head  20  and the socket  100 . Contact occurs between the sides  104  and the head  20 , and clearance occurs between the corners  106  and the head  20 . 
         [0041]    Socket  100  may provide a more uniform polyaxial connection with the head  20  than that provided by the previous sockets  40 ,  70 . Socket  100  is shown with five sides  104 , while socket  40  is shown with four sides  42 , and socket  70  is shown with six sides  74 . Sockets with an even number of sides have facing sides and facing corners. The internal width of the socket is less between facing sides than it is between facing corners. The resistance to head engagement in the socket when the head is angled toward a corner is less than the resistance when the head is angled toward a side. In contrast, the socket  100  has an odd number of sides. Each side  104  faces a corner  106 . The resistance to head engagement may be less directional for socket  100  than for sockets  40  or  70 . 
         [0042]      FIGS. 15A-B  show yet another socket  120  for use with the head  20  in a polyaxial locking interconnection. Socket  120  illustrates a principle that applies to any of the sockets disclosed herein. The sockets  40 ,  70 , and  100  are all shown extending perpendicular to, or normal to, a device surface surrounding the socket. It will be appreciated that this is a design convenience. Any of the sockets disclosed herein may extend into a device at an acute angle which, in this specification, is defined as an angle which is greater than zero degrees and less than ninety degrees.  FIG. 15A-B  show that socket  120  extends into a device at an acute angle  114 . Otherwise, socket  120  is the same as socket  100 , and may provide the same advantages with regard to uniform head  20  insertion effort at various head insertion angles. 
         [0043]      FIGS. 17A-17C  show yet another socket  130  for use with head  20 . Socket  130  is another noncircular hole, which may have a longitudinal axis  132 . The socket  130  may be formed in any medical device component, such as a plate, washer, rod, link, bone-contacting component, articular component, and the like. The socket  130  may extend completely through a component, or only partially through the component. The socket  130  may include two or more sides in a polygonal or poly-lobular arrangement. The socket  130  may have five sides  134  and five rounded corners  136 , however the corners  136  may be sharp instead. The sides  134  may bulge toward the interior of the socket  130 . The socket  130  may have a constant cross-sectional geometry over the full depth of the socket  130 . Alternatively, the socket  130  may taper ( FIG. 17B ) or bulge along its length. The socket  130  may have a spherical or partial spherical interior. The socket  130  may twist along its depth. 
         [0044]    The socket  130  includes an internal corrugation  138  which includes alternating peaks  140  and valleys  142  along the depth of the socket  130  or a portion thereof. The peaks  140  and/or valleys  142  may be sharp or blunt. The peaks  140  may lie upon, or follow, the interior surface of the socket  130 . The valleys  142  may be described as indentations into the interior surface of the socket  130 , and thus the valleys  142  may also follow the interior surface of the socket  130 , albeit offset below the interior surface. The valleys  142  may follow the interior surface exactly with a constant offset, or generally, with a variable offset. The internal corrugation  138  may be intact, or uninterrupted, throughout its extent so that all of the peaks  140  and valleys  142  are intact. 
         [0045]    The internal corrugations  138  may be formed by a single indentation, or valley  142 , which winds around the socket  130  while progressing longitudinally within the socket  130 . This arrangement is best seen in  FIG. 17B . More than one indentation may be present. Additional indentations may wind around the socket  130  with the single indentation. The longitudinal progression per circuit around the socket  130  may be constant or variable.  FIG. 17C  shows a sketch depicting a sweep profile  144  for the corrugation  138 . Sockets  40 ,  70  may each employ a similar sweep profile for the corrugations  46 ,  78 . Where more than one indentation is present, a similar number of sweep profiles may be included. 
         [0046]    In use, the head  20  may be inserted into the socket  130  with the axes  36 ,  132  aligned or coaxial, or misaligned, as described above for socket  40 . In either arrangement, the external corrugations  30  of the head  20  may engage with the internal corrugation feature  138  of the socket  130  to lock the head  20  at a range of angles with respect to the socket  130 . The incongruent shapes of the head  20  and socket  130  provide alternating zones of contact and clearance between the head  20  and the socket  130 . Contact occurs between the sides  134  and the head  20 , and clearance occurs between the corners  136  and the head  20 . Socket  130  may provide the same advantages with regard to uniform head  20  insertion effort at various head insertion angles as does socket  100 . 
         [0047]      FIGS. 18A-18B  show yet another socket  150  for use with the head  20  in a polyaxial locking interconnection. Socket  150  is another noncircular hole, which may have a longitudinal axis  152 . The socket  150  may be formed in any medical device component, such as a plate, washer, rod, link, bone-contacting component, articular component, and the like. The socket  150  may extend completely through a component, or only partially through the component. The socket  150  may include two or more sides in a polygonal or poly-lobular arrangement. The socket  150  may have six sides  154  and six rounded corners  156 , however the corners  156  may be sharp instead. The sides  154  may bulge toward the interior of the socket  150 . The socket  150  may have a constant cross-sectional geometry over the full depth of the socket  150 . Alternatively, the socket  150  may taper ( FIG. 18A ) or bulge along its length. The socket  150  may have a spherical or partial spherical interior. The socket  150  may twist along its depth. 
         [0048]    The socket  150  includes an internal corrugation  158  which includes alternating peaks  160  and valleys  162  along the depth of the socket  150  or a portion thereof. The peaks  160  and/or valleys  162  may be sharp or blunt. The peaks  160  may lie upon, or follow, the interior surface of the socket  150 . The valleys  162  may be described as indentations into the interior surface of the socket  150 , and thus the valleys  162  may also follow the interior surface of the socket  150 , albeit offset below the interior surface. The valleys  162  may follow the interior surface exactly with a constant offset, or generally, with a variable offset. The internal corrugation  158  may be intact, uninterrupted, throughout its extent so that all of the peaks  160  and valleys  162  are intact. 
         [0049]    The internal corrugations  158  may be formed by a single indentation, or valley  162 , which winds around the socket  150  while progressing longitudinally within the socket  150 . This arrangement is best seen in  FIG. 19B . More than one indentation may be present. Additional indentations may wind around the socket  150  with the single indentation. The longitudinal progression per circuit around the socket  150  may be constant or variable. 
         [0050]    In use, the head  20  may be inserted into the socket  150  with the axes  36 ,  152  aligned or coaxial, or misaligned, as described above for socket  40 . In either arrangement, the external corrugations  30  of the head  20  may engage with the internal corrugation feature  158  of the socket  150  to lock the head  20  at a range of angles with respect to the socket  150 . The incongruent shapes of the head  20  and socket  150  provide alternating zones of contact and clearance between the head  20  and the socket  150 . Contact occurs between the sides  154  and the head  20 , and clearance occurs between the corners  156  and the head  20 . Socket  150  may provide the same advantages with regard to uniform head  20  insertion effort at various head insertion angles as does socket  100 . 
         [0051]    While the present disclosure has been made with reference to regularly shaped sockets  40 ,  70 ,  100 ,  120 ,  130 ,  150 , these sockets may also be irregularly formed so that the spacing and size of each feature in a socket may be different. For example, each corner may have a unique radius. This applies to each feature described and shown herein. Any of the sockets disclosed herein may transform over its length from a first polygon shape to a second shape. The second shape may be a different polygon shape, a circle, or another profile. 
         [0052]    The components disclosed herein may be fabricated from metals, alloys, polymers, plastics, ceramics, glasses, composite materials, or combinations thereof, including but not limited to: PEEK, titanium, titanium alloys, commercially pure titanium grade 2, ASTM F67, Nitinol, cobalt chrome, stainless steel, ultra high molecular weight polyethylene (UHMWPE), biocompatible materials, and biodegradable materials, among others. Different materials may be used for different parts. Coatings may be present. Different materials may be used within a single part. Any component disclosed herein may be colored, coded or otherwise marked to make it easier for a user to identify the type and size of the component, the setting, the function(s) of the component, and the like. 
         [0053]    It should be understood that the present systems, kits, apparatuses, and methods are not intended to be limited to the particular forms disclosed. Rather, they are to cover all combinations, modifications, equivalents, and alternatives falling within the scope of the claims. 
         [0054]    The claims are not to be interpreted as including means-plus- or step-plus-function limitations, unless such a limitation is explicitly recited in a given claim using the phrase(s) “means for” or “step for,” respectively. 
         [0055]    The term “coupled” is defined as connected, although not necessarily directly, and not necessarily mechanically. 
         [0056]    The use of the word “a” or “an” when used in conjunction with the term “comprising” in the claims and/or the specification may mean “one,” but it is also consistent with the meaning of “one or more” or “at least one.” The term “about” means, in general, the stated value plus or minus 5%. The use of the term “or” in the claims is used to mean “and/or” unless explicitly indicated to refer to alternatives only or the alternative are mutually exclusive, although the disclosure supports a definition that refers to only alternatives and “and/or.” 
         [0057]    The terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”) and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a method or device that “comprises,” “has,” “includes” or “contains” one or more steps or elements, possesses those one or more steps or elements, but is not limited to possessing only those one or more elements. Likewise, a step of a method or an element of a device that “comprises,” “has,” “includes” or “contains” one or more features, possesses those one or more features, but is not limited to possessing only those one or more features. Furthermore, a device or structure that is configured in a certain way is configured in at least that way, but may also be configured in ways that are not listed. 
         [0058]    In the foregoing Detailed Description, various features are grouped together in several examples for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the examples of the invention require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed example. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate example.