Abstract:
A prosthesis can have a wall portion that deforms to conform to a surface. The deformation of the wall can be plastic (i.e. permanent) or elastic (i.e. able to return to the pre-deformed configuration). The surface can be an anatomical surface.

Description:
FIELD 
       [0001]    The subject disclosure relates to implants, and particularly to implants with at least one deformable surface. 
       BACKGROUND 
       [0002]    This section provides background information related to the present disclosure which is not necessarily prior art. 
         [0003]    When implanting a prosthesis, a prosthetic member can be positioned against a hard, such as a boney, portion of an anatomy. The anatomy can be of any appropriate subject, such as a human patient or an animal patient. Generally, the boney portion is prepared for receiving the prosthetic member by forming the bone to substantially precisely fit or conform to the shape of the preformed prosthetic member. This requires removal of bone mass of the subject. For example, an acetabulum can be reamed with an acetabular reamer to form a curved void to receive an acetabular prosthesis. 
       SUMMARY 
       [0004]    This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features. 
         [0005]    A prosthetic implant can be positioned in the anatomy to replace a portion of an anatomy. The anatomy may be of any appropriate subject, such as a human subject, an animal subject, or any selected subject anatomy. Additionally, a subject includes any portion or member into which a prosthesis or replacement member may be positioned. 
         [0006]    The prosthetic member can be positioned in an anatomy in a generally non-smoothly prepared, partially prepared, or unprepared region. For example, an acetabular prosthesis can be positioned into an acetabulum that is reamed to a non-smooth or non-completely reamed surface. An acetabulum can be prepared without requiring an excessive removal of natural bone or tissue portions of the anatomy and a prosthesis can be positioned within the partially prepared acetabulum to replace the natural acetabulum. Thus, rather than completely reaming an acetabulum to form a substantially curved or hemispherical surface, an acetabular prosthesis can be positioned into an acetabulum where only the diseased or boney portions have been removed. The acetabular prosthesis can then have a wall portion that deforms to conform to the acetabular surface. The deformation can be plastic (i.e. permanent) or elastic (i.e. able to return to the pre-deformed configuration). 
         [0007]    Additionally, prosthetic members can be positioned in or adjacent to and in contact with any appropriate anatomical portions, such as a proximal tibia, proximal femur, glenoid, or other appropriate anatomical surface. Generally, the anatomical surfaces, which can generally include boney surfaces, need not be completely reamed or smooth while still allowing for appropriate contact and connection of the prosthetic member with the anatomy. At least one surface of the prosthetic member may deform to match or conform to the boney surface. 
         [0008]    Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
     
    
     
       DRAWINGS 
         [0009]    The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
           [0010]      FIG. 1  is a perspective view of an acetabular prosthesis assembly, according to various embodiments; 
           [0011]      FIG. 2  is a cross-section of the acetabular prosthesis assembly of  FIG. 1  taken along the line  2 - 2 ; 
           [0012]      FIG. 2A  is a detailed exploded view taken within circle  2 A of  FIG. 2 . 
           [0013]      FIG. 3  is a proximal tibial prosthesis assembly, according to various embodiments; 
           [0014]      FIG. 4  is a cross-section of the tibial prosthesis of  FIG. 3  taken along the line  4 - 4 ; 
           [0015]      FIG. 5  is an environmental view of the acetabular prosthesis of  FIG. 1 ; 
           [0016]      FIG. 6  is an implanted environmental view of the acetabular prosthesis of  FIG. 1 ; and 
           [0017]      FIG. 7  is a detailed cross-sectional view of the implanted acetabular prosthesis taken from  FIG. 6 . 
       
    
    
       [0018]    Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
       DETAILED DESCRIPTION 
       [0019]    Example embodiments will now be described more fully with reference to the accompanying drawings. 
         [0020]    With reference to  FIG. 1  an acetabular prosthesis assembly  18  is illustrated. The acetabular assembly  18  can include an acetabular shell or cup  20 . The acetabular prosthesis assembly  18  and/or cup  20  can be similar to any generally available prosthesis such as the Ringloc® acetabular prosthesis, sold by Biomet, Inc. having a place of business in Indiana, United States. The acetabular prosthesis can generally include an exterior surface  22  an upper rim  24  and an interior surface  26 . Positioned within the interior surface  26  can be a bearing member or prosthetic portion  30 . The bearing member  30  can include an internal articulating surface  32  and an upper rim  34 . The design of the acetabular bearing  30  can be similar to the design of the bearing member of the acetabular prosthesis, as discussed above. 
         [0021]    The exterior surface  22  can have a substantially curved surface, and may be substantially hemispherical, according to various designs. Additionally, the exterior surface  22  can have a boney ingrowth portion, such as a porous titanium or other porous metal construct, including Regenerex® porous metal sold by Biomet, Inc. Additionally, a plasma coating or other porous coating can be provided on the exterior surface  22  of the acetabular prosthesis  20 . Further, screw holes or other fixation features can be provided to interconnect the acetabular prosthesis  20  with the selected subject. Various implantation and fixation mechanisms will not be described in detail here. 
         [0022]    With continuing reference to  FIG. 1  and additional reference to  FIG. 2 , the acetabular prosthesis  20  can be formed such that the bearing member  30  is fixed within the inner or relative to the inner surface  26  via a ring locking member  36  that is received within a first groove  38  of the bearing member  30  and a second groove  40  of the prosthesis  20 . The second groove  40  can be formed in the surface  26  of the prosthesis member  20  in an appropriate location relative to the upper rim  24 . 
         [0023]    The upper rim  24  can be formed to have a plurality of regions extending between the exterior surface  22  and the interior surface  26 . For example, a first or exterior region  50  of the upper rim  24  can extend between the exterior surface  22  of the prosthesis  20  and a first boundary or region  52  that is generally defined by an internal wall surface  22   a  of the prosthesis  20 . A second region  54  can extend from the first boundary  52  to a second boundary  56  that is generally defined by a second internal surface  26   a  of the prosthesis  20 . An internal or third region  58  can extend from the second boundary  56  to the internal surface  26  of the prosthesis  20 . Defined between the first inner surface  22   a  and the second inner surface  26   a  can be a void or opening  70 . The void  70  can be substantially enclosed by the prosthesis  20  between the external surface  22  and the internal surface  26 , and at least a portion of the upper rim wall  24 . The void  70  defines an open area or void area into which an outer wall  72 , that defines the surfaces  22 ,  22   a  can compress or deform into, as discussed further herein. 
         [0024]    The upper rim wall  24 , including the second region  54 , is generally substantially rigid. The rigid upper rim wall  24 , including the middle or intermediate region  54  can include appropriate thickness or other physical property or feature so that it will not substantially deform during implantation and positioning of the prosthesis  20  within a subject. As discussed herein, the outer wall  72  can deform into the void  70 , but the upper rim wall  24  will remain substantially rigid such that the upper rim wall  24  does not deform. The void  70  can include any appropriate dimension, for example, a dimension  80  that extends between the first region  42  and the second region  56 . The outer wall  72  can further include a thickness  82  that can allow the outer wall  72  to deform into the void  70 , as discussed further herein. The prosthesis  20 , therefore, can further include an internal wall  84  that defines the inner surface  26  and includes a thickness  86 . Generally, the thickness  82  of the outer wall  72  is less than the thickness  86  of the inner wall  84 . However, it is understood, that the thickness  82  of the outer wall  72  can be substantially equivalent or identical to the thickness  86  of the inner wall  84 . 
         [0025]    The acetabular prosthesis  20  can be formed of various materials, such as appropriate biocompatible metals. For example, titanium and cobalt-chromium alloys can be used to form the acetabular prosthesis  20 . Additionally, the prosthesis member  20  can be formed of an appropriate polymer material to be positioned within the anatomy. Appropriate bearing materials can be used for the bearing member  30 , such as high molecular weight polyethylene that is formed into a selected shape to be positioned within the prosthesis  20 . The inner surface  26  can be formed to appropriately receive the bearing member  30 , such as being formed with a highly polished or mirrored polished surface. 
         [0026]    The various thicknesses, such as the thickness of the outer wall  72  and the inner wall  84  can vary depending upon the material selected for forming the prosthesis  20 . The thickness of the outer wall  72  is generally selected to allow for deformation by contact with bone and a force provided by a user, such as a human surgeon. Thus, the thickness is generally selected to allow for a user to deform the outer wall  72 . For example, a prosthesis having an outer wall formed of titanium may have the outer wall  72  have a thickness  82  of about 0.25 millimeters (mm) to about 1.0 mm. The inner wall  84  can have the thickness  86  of about 2.5 mm to about 4 mm. The dimension of the void  70 , such as the dimension  80  near the upper rim  24  can include a dimension of 0.5 mm to about 1.5 mm to allow for an appropriate amount of deformation of the outer wall  72  during implantation. 
         [0027]    The prosthesis  20  can further include an opening or connection  90  that can be formed in any appropriate configuration to allow for connection of a supply device  250  ( FIG. 6 ), such as a syringe. The supply device  250  can supply an appropriate material into the void  70 . Appropriate materials can include hardening materials, such as polymerizing or polymerizable materials. The material can fill the void  70  to provide additional rigidity to the outer wall  72  at a selected point in time. The material can fill the void  70  to provide for physical contact between the first surface  22   a  and the second surface  26   a.    
         [0028]    With continued reference to  FIG. 2  and additional reference to  FIG. 2A , the prosthesis  20  can be formed in any appropriate manner. For example, the exterior wall  72  and interior wall  84  can be formed as two separate members that are interconnected with a top wall  92 , which is also separate from the exterior wall  72  and the interior wall  84 , that forms the upper rim  24 . The three wall portions  72 ,  84  and  92  can be interconnected within an appropriate connection mechanism including welding, adhesives, brazing, spin welding, or other appropriate mechanism. Accordingly, each separate portion of the prosthesis  20  can be formed separately according to appropriate manufacturing techniques, with selected dimensions, physical properties, and/or various materials. For example, as discussed above, the exterior wall  72  can be formed to deform during implantation and positioning of the prosthesis  20 . Accordingly, the exterior wall  72  can be formed of a material that is different than the interior wall  84  and/or the upper wall  92 . Furthermore, each of the wall portions can be formed at different thicknesses, plurality of thicknesses for each of the wall portions, or other appropriate dimensions or physical properties. 
         [0029]    It is also understood that the interconnection of the wall members can occur at any appropriate time, such as during manufacturing of the prosthesis  20  such that the prosthesis  20  is provided to a user, such as a surgeon, as a single connected member or piece. Nevertheless, each of the wall portions,  72 ,  84 , and  92  can be formed separately and interconnected. In addition, it is understood that the upper wall  92  can be formed integrally as a single piece with either one of the inner wall  94  or the exterior wall  72  and only the other wall connected to the appropriate wall  92 . Thus, the prosthesis  20  can be formed of a plurality of pieces including three pieces, two pieces, or formed as a single one piece member. 
         [0030]    With reference to  FIGS. 3 and 4 , a tibial tray prosthesis assembly  100  is illustrated. The tibial prosthesis  100  can be similar to the Vanguard® Knee System sold by Biomet, Inc. It is understood that a knee system can further include a distal femoral prosthetic member that can engage a distal femur to articulate with the tibial prosthesis assembly  100 . The tibial prosthesis assembly  100  can include a tibial tray member or portion  102  and a bearing member  104 . The tibial tray member  102  can further include various engaging portions to engage the bearing member  104 . For example, a posterior engagement portion or ledge  108  can include a finger or engagement ledge  110  to engage the bearing member  104 . Additionally, anterior engagement fingers or portions  112  and  114  can further include engagement ledges or fingers  116  and  118  to engage the bearing member  104 . It is further understood that the various locking bars or members, not specifically illustrated, can be provided to interconnect the bearing member  104  with the tibial tray portion  102 . 
         [0031]    Generally, an upper surface  120  of the tray member  102  can be polished, such as with a mirror polished surface to contact the bearing member  104 . The bearing member  104  can further include cut-outs or receiving grooves  122  and/or  124  to engage or contact with the finger members  110  and/or  116 ,  118 . The bearing member  104  can be held substantially immobile or be mobile relative to the tibial tray  102 . The bearing member  104  can be formed of an appropriate material, such as a polymer material including the high molecular weight polyethylene as discussed above for the bearing portion  30 . Further, the tibial tray member  102  can be formed of appropriate materials, such as metals, polymers, or other appropriate materials similar to the prosthesis  20  as discussed above. 
         [0032]    The tibial tray  102  can be positioned against a tibia  130  as illustrated in phantom in  FIG. 4 . The tibia can include a proximal surface  132  that is prepared or partially prepared to receive the tibial tray  102 . As is understood to one skilled in the art, the proximal tibial surface  132  can generally be substantially resected to provide a substantially smooth or flat surface for engagement with a tibial tray. Alternatively, the proximal surface  132  can be resected to only remove disease or a selected minimal amount of bone such that the surface is not completely flat for engagement with an external surface  140  of the tibial tray  102 . The external surface  140  can be an external surface of a bottom or external wall  142  that can have a thickness  144 . The tibial tray  102  can further have a second or upper wall  146  that has a second thickness  148 . The first wall  142  can have a first internal surface  142   a  and the second wall  146  can have a second internal surface  146   a.  Defined between the surfaces  142   a  and  146   a  can be a void  150 . A dimension  152  of the void  150  between the first surface  142   a  and the second surface  146   a  can be initially provided and can be selected to allow for deformation of the external wall  142  into the void  150 , as discussed further herein. 
         [0033]    As discussed above, the void  150  can allow for deformation of the external wall  142  into the void when contacting the surface  132  of the tibia  130 . The external wall  142  can deform into the void  150  when contacting the surface  132  with an appropriate force. Specifically, the surface  142   a  moves into at least a portion of the initial volume of the void  150 . 
         [0034]    An outer edge or wall  160  can be provided with an appropriate thickness and dimension and may be substantially rigid during contacting of the external wall  142  with the upper tibial surface  132 . As discussed above, regarding the upper rim wall  24  of the acetabular prosthesis  20  the exterior wall  160  of the tibial tray  102  can be substantially rigid so as to not move or change dimensions (i.e. deform) when contacting the tibia  130  to deform the external wall  142 . For example, the external or perimeter wall  160  can extend from the exterior surface  140  to first region  162  that is generally equivalent with the inner surface  142   a  and then to a second region  164  that is generally equivalent with the second inner surface  146   a.  Accordingly, the external wall  160  may be provided to at least be substantially rigid for the area between the first region  162  and the second region  164 . Thus, the external wall  142  can deform into the void  150  while the external wall  160  maintains substantially rigid and undeformed. 
         [0035]    Additionally, a connection  170  can be provided to allow for connection of a supply, such as a material supply as discussed above. A material can be placed within the void  150  to allow for a physical contact between the first surface  142   a  and the second surface  146   a  to provide additional rigidity when the external wall  142  is deformed into the void  150 . It is understood, however, that filling the void  150  with a material is not required. 
         [0036]    It is further understood that the tibial tray prosthesis  102  can be formed in a manner similar to the acetabular prosthesis  20  discussed above. In particular, the first wall  142  and the second wall  146  can be formed separately from the external perimeter wall  160 . All three of the walls  142 ,  146 , and  160  can then be connected together with an appropriate connection mechanism such as welding, brazing, adhesives, or other appropriate connection mechanism. Moreover, the external perimeter wall  160  can be formed with at least one of the first wall  142  or the second wall  146  and the other of the first wall  142  or the second wall  146  can be connected thereto. Alternatively, all of the walls  142 ,  146 , and  160  can all be formed as a single piece to provide the tibial tray prosthesis  102 . Regardless of the mechanism for providing the tibial tray  102 , the wall  142  is generally provided to deform relative to the tibial surface  132  such that at least the external surface  140  of the external wall  142  will conform, such as mirror, the shape and geometry of the tibial surface  132 . 
         [0037]    Returning reference to  FIGS. 1 and 2  and with additional reference to  FIGS. 5-7 , the acetabular prosthesis  20  can be positioned within an acetabulum  200  of a pelvis  202  of a selected patient. The acetabulum  200  can be prepared to receive the acetabular prosthesis  20  according to any appropriate procedure. For example, a user, such as a surgeon, can prepare the acetabulum  200  by removing selected portions of the acetabulum  200 . However, a reamer and/or other bone removal tools may not be required to form a substantially smooth or congruent surface of the acetabulum  200 . A prepared smooth surface is a surface that has only minor variations from a single line. The acetabulum  200  can, however, have a prepared surface  210  that is not substantially smooth or perfectly curved. 
         [0038]    The prepared surface  210  of the acetabulum  200  can include valley or depression regions  212  and peak regions  214 . The valley regions  212  and the peak regions  214  can be understood to be formed along the entire three-dimensional surface or region of the acetabulum  200 , and is illustrated in two dimensions in  FIG. 5  simply for the current discussion. The prepared acetabular surface  210 , therefore, can contact the external surface  22  of the acetabular prosthesis  20  when the acetabular prosthesis  20  is positioned into the acetabulum  200 . An appropriate implantation tool  220  can be used to position the acetabular prosthesis  20  into the prepared acetabulum  200 . The implantation tool  220  can be any appropriate configuration. For example, the implantation tool can include an internal surface contacting region  222  and a rim contacting region  224  that is interconnected with a handle or elongated member  226 . Various impaction instruments, such as a hammer, can be used to impact the acetabular prosthesis  20  into the acetabulum  200 . An appropriate force can be provided through the implantation tool  220  to impact the acetabular prosthesis  20  into the prepared acetabulum  200 . 
         [0039]    Turning reference to  FIGS. 6 and 7 , the impacted or placed acetabular prosthesis  20  once positioned within the prepared acetabulum  200  can include an external deformed surface  22 ′ that can substantially conform or match the shape (e.g. form a mirror match) of the prepared acetabular surface  210 . The deformation of the external surface  22 ′ can be substantially identical or may closely match the prepared acetabular surface  210 . For example, a gap or space between the prepared acetabular surface  210  and the external surface  22 ′ can generally be less than about 0.5 mm, including about 1.5 mm. It is understood that the external conformed surface  22 ′ would be substantially deformed to match the shape of the prepared acetabular surface  210  and need not include a perfect or smooth arc or curved surface from one rim portion to another rim portion going through a central axis  20   a  of the acetabular prosthesis  20 . 
         [0040]    With particular reference to  FIG. 7 , the peak region  214  can engage the exterior surface  22 ′ to deform the exterior surface  22 ′ into the void  70  of the acetabular prosthesis  20 . The bone peak  214  can form a valley  230  in the deformed external surface  22 ′. The valley  230  can also be a depression that is substantially a point depression within the external wall  72  of the acetabular prosthesis  20 . The depression or valley  230  can be surrounded or adjacent to peak regions  232  and  234 . The void  70  allows the external wall  72  to be deformed into the void  70  while allowing the wall  84  and/or the interior surface  26  of the acetabular prosthesis  20  to remain substantially unchanged such that the inner wall  84  is substantially not deformed. In other words, the inner wall  84  and/or the surface  26  remain substantially in an original or provided configuration. The internal surface  26 , as discussed above, is configured, such as with an initial configuration, to contact the bearing member  30 . Accordingly, the bearing member  30  is formed to have a surface that engages the internal surface  26  of the acetabular prosthesis  20  in a selected manner. Maintaining the internal surface  26  in a non-deformed configuration, therefore, allows for the internal surface  26  to receive the bearing member  30  in an appropriate manner for replacing the acetabulum  200  of the patient. The outer wall  72  and/or the surface  22 ′ may be irreversibly or plastically deformed. 
         [0041]    Regarding reference to  FIG. 6 , a supply  250  can engage the connection  90  to fill the void  70  with a selected material, such as a bone cement material. The bone cement can be any appropriate polymerizing or hardening material that can fill the void  70  and provide a physical rigidness between the inner surface  26   a  and the inner surface  22   a.  The additional rigidity can assist in maintaining the shape of the external wall  72  once the acetabular prosthesis  20  is implanted in to the acetabulum  200 . Accordingly, the initially deformed shape of the external wall  72  can be maintained for the life of the acetabular prosthesis  20 . 
         [0042]    It is further understood that the tibial tray prosthesis  100  can be implanted and the external wall  142  can be deformed in a manner similar to the acetabular prosthesis  20 , as illustrated in  FIGS. 6 and 7  for the acetabular prosthesis  20 . It is further understood that selected additional prosthetic members, such as glenoid prostheses, and other prosthetic members can also include walls that can be deformed when contacting or engaged into the anatomy of a subject. Accordingly, the exemplary embodiments of an acetabular prosthesis  20  and the tibial tray prosthesis  102  are merely exemplary and not the limiting examples. Additionally, it is understood that the external surface of an appropriate prosthetic member can engage a substantially smooth or fully resected receiving surface, such as a fully reamed acetabulum  200 . The external wall may deform, even if to a lesser degree than illustrated above, when the acetabulum or other appropriate surface is completely resected or reamed to prepare the selected surface, for implantation of a prosthetic member. The deformation of the external wall may still allow for a greater contact of the prosthetic member with the surface, prepared to any extent or with no preparation to assist in maintaining and achieving a greater longevity of the prosthetic member, reduced possibility of loosening of the prosthetic member, and a reduced possibility or requirement for revision procedure in the future. Additionally, the deformation can allow for greater loading of the contacted bone to assist in resisting resorption of the bone and assist in allowing bone growth and/or bone ingrowth into the prosthetic member after implantation. 
         [0043]    The prosthesis, according to the various disclosed embodiments, can be formed without seams, such as formed as a single member with an internal void. Thus, the wall may be formed as a continuous portion. Further, the prosthesis formed with a deformable wall can be provided in a single size to fit a broader range of patient sizes. For example, a single prosthesis need not be provided for multiple joint gaps, thicknesses, etc. This can also reduce inventory of a supplier, such as a hospital inventory, and related costs. Moreover, the deformation allows for variability of an individual prosthetic member, thus user selection of a single prosthetic member can be more variable and allow greater intra-procedure customization by a user, such as a surgeon. Also, a limiting feature can be provided to limit or eliminate deformation. Thus, a user can select to engage the limiting feature to limit or elimination deformation of a prosthetic member, for selected purposes. 
         [0044]    The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.