Patent Publication Number: US-2013245780-A1

Title: Acetabular Cartilage Implant

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of U.S. patent application Ser. No. 12/915,373 filed on Oct. 29, 2010. This application includes subject matter similar to that disclosed in U.S. patent application Ser. No. 12/915,366, filed on Oct. 29, 2010, published as U.S. Pat. App. Pub. No. 2012/0109328. The entire disclosures of the above applications are incorporated herein by reference. 
    
    
     FIELD 
     An implantable prosthesis to repair or replace a portion of an anatomy, particularly an implantable prosthesis to replace a portion of an articulation region or cartilage of an acetabulum of an anatomy. 
     BACKGROUND 
     This section provides background information related to the present disclosure which is not necessarily prior art. 
     In an anatomy, such as a human anatomy or other animal anatomy, various bones articulate or move relative to one another. At bone articulation regions, the bones are covered with a material and fluid that ease or cushion articulation. The covering, often cartilage, however can wear or be damaged for various reasons. 
     One articulation joint in a human anatomy includes the acetabulum which articulates with the femoral head. The joint between the acetabulum and the femoral head is a substantially weight bearing joint as it connects a torso and legs of a human. Accordingly, damage to the acetabulum can cause pain in movement of the human due to decreased cushioning and smoothness of articulation movement due to the damage in the acetabulum. Generally, upon injury or degradation of an acetabulum, the acetabulum can be reamed and replaced with an acetabular prosthesis. The acetabular prosthesis, however, generally replaces the entire acetabular articulation region regardless of the extent of injury or damage to the cartilage in the acetabulum. 
     SUMMARY 
     This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features. 
     According to various embodiments, an acetabular prosthesis for fixing in an acetabulum is disclosed. The acetabular prosthesis can include a member having a concave articulation surface that is operable to articulate with a natural femoral head. The concave surface is formed of pyrolytic carbon to have physical properties substantially similar to the natural femoral head to substantially reduce wear on the natural femoral head compared to a harder articulation surface. According to various embodiments, the entire member is formed of the same pyrolytic carbon or has a substrate substantially completely covered with the pyrolytic carbon. That is at least any portion that will articulate with the femoral head is covered with the pyrolytic carbon. The acetabular prosthesis can further include a bone connection portion extending away from the articulation surface to engage bone near the concave articulation surface. The concave articulation surface is configured to replace a damaged region of acetabular cartilage in an acetabulum. 
     According to various embodiments, an acetabular prosthesis for fixing in an acetabulum is disclosed. The acetabular prosthesis can include a first region extending away from a first position and having a convex surface on a first side and a second region extending from the first position and having a concave surface on the first side. The prosthesis, therefore, can include both a concave and a convex portion for engagement with a femoral head. The prosthesis can further include a bone connection region on a second side of at least one of the first region and the second region. Generally, the second region is configured to replace a portion of an acetabular cartilage. 
     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 
       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. 
         FIG. 1  is an environmental view of an acetabular prosthesis; 
         FIG. 2A  is a plan view of an acetabular prosthesis; 
       FIG.  2 A′ is a top plan view of the acetabular prosthesis of  FIG. 2A ; 
         FIG. 2B  is a side plan view of an acetabular prosthesis; 
         FIG. 2C  is a side plan view of an acetabular prosthesis; 
         FIG. 2D  is a side plan view of an acetabular prosthesis; 
         FIG. 3A  is a side plan exploded view of an acetabular prosthesis; 
         FIG. 3B  is a side plan exploded view of an acetabular prosthesis; 
         FIG. 3C  is a side plan view of an acetabular prosthesis; 
         FIG. 4A  is a prospective view of an acetabular prosthesis; 
         FIG. 4B  is a prospective view of an acetabular prosthesis; 
         FIG. 5A  is a side plan view of an acetabular prosthesis; 
         FIG. 5B  is a side plan view of an acetabular prosthesis; 
         FIG. 6A  is a top plan view of an acetabular prosthesis; 
         FIG. 6B  is a top plan view of an acetabular prosthesis; 
         FIG. 6C  is a top plan view of an acetabular prosthesis; 
         FIG. 6D  is a top plan view of an acetabular prosthesis; 
         FIG. 7  is a environmental view of an acetabular prosthesis; 
         FIG. 8  is an environmental view of an acetabular and labrum prosthesis; 
         FIG. 9  is an environmental view of an acetabular and labrum prosthesis; 
         FIG. 10  is a top prospective view of an acetabular and labrum prosthesis; 
         FIG. 11  is a cross-sectional and environmental view of the acetabular and labrum prosthesis of  FIG. 10 ; and 
         FIG. 12  is a cross-sectional and environmental view of an acetabular and labrum prosthesis. 
     
    
    
     Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION 
     Example embodiments will now be described more fully with reference to the accompanying drawings. 
     With reference to  FIG. 1 , the human anatomy can include a pelvis  20 . The pelvis  20  defines an acetabulum  22  which can include a layer of acetabular cartilage  24  having an acetabular articulation surface  24   a  that articulates with a femoral head  26 . The femoral head  26  can also include femoral cartilage or other surface coverings to articulate with the acetabular cartilage surface  24   a . A defect or damaged region  25  may form in the acetabular cartilage  24  when the acetabular cartilage  24  becomes damaged for various reasons, such as injury, disease, natural defect, or the like. Also, the defect or damaged region  25  can be a non-continuous or non-smooth/level region of the acetabular cartilage  24  that causes issues with femoral articulation. Injury to the acetabular cartilage  24  can leave gaps or holes in the acetabular articulation surface  24   a  that can be repaired to allow for pain free and smooth articulation of the femoral head  26  relative to the acetabulum  22 . As discussed above, replacement of the entire acetabulum  22  or even all of the acetabular cartilage  24  with a prosthesis can be performed. However, a point or small prosthesis (also referred to as an implant) or pin  30  can be implanted in the acetabulum  22  and include an articulation surface  32  that can fill the defect to substantially make a continuous acetabular articulation surface  24   a  to articulate with the natural femoral head  26 . The substantially continuous acetabular articulation surface  24   a  is one that that has fewer or no depressions, holes, bumps, or other defects that can harm or wear unevenly with the femoral head  26 . Generally, the articulation surface is generally configured to fit completely within the acetabulum  22  of the pelvis  20  and be, after implantation, continuous with the surrounding and remaining articulation surface of the acetabulum  22 . In other words, the prosthesis  30 , according to various embodiments, is generally positioned to replace or only replace a portion of the acetabular cartilage  24  when undamaged portions of the cartilage can be maintained or salvaged. Furthermore, the prosthesis  30 , according to various embodiments, is positioned substantially completely or entirely within the acetabulum  22 . 
     The surface  32  of the acetabular prosthesis  30  can be formed of a material that allows for smooth articulation of the femoral head  26  without damaging the femoral head  26 . For example, pyrolytic carbon can be used to form the surface  32  of the acetabular prosthesis  30  to allow for an appropriate articulation with the femoral head  26 . Pyrolytic carbon can be used for articulation of multiple implants, as disclosed in U.S. patent application Ser. No. 12/502,642, filed on Jul. 16, 2009, incorporated herein by reference. 
     The acetabular prosthesis  30  can further include a bone fixation mechanism, in a bone connection region or portion such as a pin or a tack point  34  that extends from a base or head  36 . The pin  34 , according to various embodiments including those disclosed herein, can include a geometry and size that is smaller than the dimensions of the head  36 . Further, the pin  34  can be contained completely within a bone portion of the pelvis  20  or the acetabulum  22 , and generally below the level of any of the acetabular cartilage  24 . Thus, as discussed herein, the pin  34 , according to various embodiments, can be formed of a material different than the body  36  or the surface  32  and include a size smaller (e.g. substantially smaller in an external dimension, such as about 10-20% of the external size) than the defect  25  in the acetabular cartilage  24 . 
     According to various embodiments, as discussed herein, the acetabular prosthesis  30  can be positioned at appropriate locations within the acetabulum  22  to repair or replace the defect of the acetabular cartilage  24  without replacing all of the acetabular cartilage  24  within the acetabulum  22 . Accordingly, as discussed herein, the acetabular prosthesis  30  can be used to repair the damaged articulation region defect  25  that is smaller than the whole acetabular cartilage  24  to substantially make whole the acetabular articulation surface  24   a . Generally, the defect  25  may cause the articulation cartilage  24  to have a discontinuous articulation surface. The prosthesis, according to various embodiments, can act to cure or alleviate the defect  25 . 
     With reference to  FIG. 2A , the acetabular prosthesis  30  can include the surface  32  that is formed to substantially match the contour of the acetabular cartilage  24  at the area where it is to be positioned, thus creating at least a local substantially continuous acetabular articulation surface  24   a . Generally, the surface  32  of the acetabular prosthesis  30  defines a concave shape. The surface  32 , however, can be made to match a specific patient based upon image data acquired of the patient prior to performing a procedure or measurements made while forming a procedure. The acetabular prosthesis  30  can be formed of pyrolytic carbon which can be shaped during a procedure to place the acetabular prosthesis within the acetabulum  22  including shaping and polishing of the surface  32 . 
     The acetabular prosthesis  30  can include the top or body portion  36  from which the bone fixation portion  34  extends. The body portion  36  can be formed to abut or also fit substantially within a blind bore formed in a bone of the pelvis  20  and also to assist in fixation of the acetabular prosthesis  30  to the bone of the pelvis  20 . The body  36  can be generally cylindrical or include a taper to assist in fixation or positioning of the prosthesis  30  within the defect  25  of the bone of the pelvis  20 . 
     The body portion  36  can include a height or thickness  37  appropriate to substantially match a thickness of an adjacent portion of acetabular cartilage  24 . The height  37  can make sure the articulation surface  32  is continuous and substantially non-interrupted with the adjacent acetabular cartilage  24 . Also, as discussed herein the outer perimeter of the body  36  can be substantially round or polygonal. The outer edges of the body can be curved, straight, or have portions that are straight and other portions that are curved. 
     The bone attachment portion  34  can be used to initially place and hold or to increase fixation of the acetabular prosthesis  30  to the bone of the pelvis  20 . As discussed herein, the body portion  36  may also assist in fixation of the acetabular prosthesis  30 . 
     According to various embodiments, all portions of the acetabular prosthesis  30  can be formed of a single material. An exemplary material can include pyrolytic carbon, as discussed above, which includes properties that are substantially similar to bone of a human, including flexibility and hardness. Accordingly, the pyrolytic carbon forming the acetabular prosthesis  30  can articulation with the natural femoral head  26 . Harder materials may wear the natural femur and may not be selected. This can also reduce or eliminate the need or selection of replacing the femoral head  26  with a femoral head prosthesis. 
     The bone fixation section  34  can include a spike or taper defined by a wall  40  of the acetabular prosthesis  30 . The wall  40  can be formed at an angle  42  relative to a long axis or central axis  44  of the bone attachment portion  34 . The central axis  44  can also be a central axis for the surface  32  of the acetabular prosthesis. The angle  42  can be any appropriate angle selected for fixation of the acetabular prosthesis into the pelvis  20 . For example, the angle  42  can be about 1 degree to about 45 degrees to allow for at least initial fixation of the acetabular prosthesis  30  to the bone of the pelvis. The angle  42  can also be about 5 degrees to about 30 degrees, and about 7 degrees to about 25 degrees. 
     The articulation surface  32 , as illustrated in  FIG. 2A , can be substantially concave. The concave surface of the articulation surface  32  can be provided to substantially match or allow for smooth articulation relative to the acetabular cartilage  24  and have a selected radius  48 . Thus, the articulation surface can be formed to have an appropriate radius  48 . Also, a plurality of prosthesis can be provided in a kit each with different radii. Generally, the radius  48  is selected to coincide or be continuous with the curve of the adjacent acetabular cartilage  24 . 
     The articular surface  32  can also be substantial polished to provide a smooth surface for articulation with a femoral head  26 . According to various embodiments, as discussed above, the surface  32  can be formed of pyrolytic carbon. Generally, the acetabular implant  30  will be a xeno graft. Thus, the material forming the acetabular prosthesis  30  is generally not naturally formed from the anatomy from a similar donor anatomy. Nevertheless, pyrolytic carbon can provide an articulation surface that substantially imitates the natural anatomy. Alternatively, the articulator surface  32  can be substantially highly polished biocompatible materials including ultra high molecular polyethylene and metals or metal alloys (e.g. stainless steel, cobalt chromium alloys, titanium alloys, and pure titanium). 
     As illustrated in  FIG. 2A , the acetabular prosthesis  30  can be formed as a substantially single-piece. Accordingly, the articular surface  32 , the body  36 , and the bone attachment portion  34  are a single-piece that are formed unitarily, such as through injection molding, casting, or other formation techniques. It will also be understood that the acetabular prosthesis  30  can be formed as multiple pieces and integrally fixed together into one-piece prior to implantation into the pelvis  20 . For example, the body  36  can be formed and the bone attachment portion  34  can be fixed to the body by using appropriate techniques, such as fusing, adhesives, welding, and the like. Such modular initial construction can still allow the acetabular prosthesis  30  to be implanted as an integral one-piece prosthesis, even if the prosthesis is not unitarily formed as a single-piece. 
     With reference to  FIG. 2B , an acetabular prosthesis  30   a  is illustrated. The acetabular prosthesis  30   a  can include portions that are similar to the acetabular prosthesis  30  including a body  36   a  and an articulation surface  32   a . A bone attachment portion  50 , however, can include one or more barbs, such as a first barb  52  and a second barb  54 . The second barb  54  can be a terminal barb that also includes a distal tip that can be shaped to allow for impaction into the pelvis  20 . The barbs  52 ,  54  can include tapered or conical surfaces that terminate in upper flat surfaces  56  and  58 , respectively. The flat surfaces  56 ,  58  can resist withdrawal of the acetabular prosthesis  30   a  from the pelvis  20  after implantation of the acetabular prosthesis  38 . It will be understood that a plurality of the barbs or a single barb can be provided to assist in holding the acetabular prosthesis  30   a  into the pelvis  20 . The taper angle of the barbs  52 ,  54  can be similar to the angle  42  of the bone connection portion  34 , but could be provided for ease of driving the acetabular prosthesis into the bone due to the positioning of the anti-withdrawal flats  56 ,  58 . 
     Again, the body  36   a  and the bone attachment portion  50  can be unitarily formed as a single piece or can be formed separately and later connected to form the single piece acetabular prosthesis  30   a . Additionally, the articulation surface  32   a  can be similar to the articular surface  32  of the acetabular prosthesis  30 . Additionally, the acetabular prosthesis  30   a  can be formed of materials that are substantially identical to the acetabular prosthesis  30  to allow for articulation with the femoral head  26  of a natural anatomy and to replace the damaged portion  25  of the acetabular cartilage  24 . 
     According to various embodiments, an acetabular prosthesis  30   b  is illustrated in  FIG. 2C . The acetabular prosthesis  30   b  can include portions similar to the acetabular prosthesis  30  including a body  36   b  and an articulation surface  32   b . The acetabular prosthesis  30   b , however, can include a bone attachment portion  60  that defines one or more twists or threads  62 . The threads  62  can allow for twisting or driving the acetabular prosthesis  30   b  into the bone of the pelvis  20 . It will be understood that the body  36   b  can include a substantially non-circular shape to allow for engagement with a tool. For example, the exterior surface of the body  36   b  can be substantially hexagonal to engage a driving tool. Alternately, the thread  62  can be used to resist withdrawal after the acetabular prosthesis is impacted axially into the bone of the pelvis  20 . Therefore, the bone fixation portion  60  need not require that the prosthesis  30   b  be twisted into the bone, but can be axially impacted, such as with a hammer. 
     The dimensions and configurations and materials of the acetabular prosthesis  30   b  can be substantially similar to those of the acetabular prosthesis  30 . Accordingly, the acetabular prosthesis  30   b  can be formed of pyrolytic carbon or other appropriate materials. Additionally, the body  36   b  can be formed unitarily as a single member with the bone attachment portion  60  or can be formed in two pieces later fixed together using appropriate fusing techniques. Additionally, the thread  62  can be formed in a mold during formation of the acetabular prosthesis  30   b  or can be worked from the bone attachment portion  60 , such as with milling or cutting. 
     An acetabular prosthesis  30   c , illustrated in  FIG. 2D , can include portions that are similar to the acetabular prosthesis  30  illustrated in  FIG. 2A . Thus, the acetabular prosthesis  30   c  can include an articulation surface  32   c  and a body  36   c . The acetabular prosthesis  30   c , however, can include a bone attachment portion  66  that includes one or a plurality of projections  68 ,  70 , according to various configurations. As exemplarily illustrated, the projection  68 ,  70  can be a substantially similar to the bone engaging portion  34  of the acetabular prosthesis  30 . It will be understood, however, that barbs can be provided on the bone attachment portion  66 , threads can be provided on the bone attachment portion  66 , or other removal restrictive mechanisms can be formed on the bone attachment portion  66 . It will be understood, however, that a plurality of projections can be provided in the bone attachment portion extending from the body  36   c  to engage the bone of the pelvis  20 . 
     The acetabular prosthesis  30   c  can be formed of appropriate materials including those discussed above regarding the acetabular prosthesis  30 . For example, the acetabular prosthesis  30  can be formed entirely of pyrolytic carbon to articulate with the natural femoral head  26 . Additionally, the bone attachment portion  66  can be formed unitarily as a single piece with the body  36   c  or can be formed separately and later fused to the body  36   c.    
     With reference to  FIG. 3A , an acetabular prosthesis  30   d  is illustrated. The acetabular prosthesis  30   d  can include an articulating surface  32   d  similar to the articulation surface  32  discussed in relation to the acetabular prosthesis  30 . The articulation surface  32   d , however, can be defined by a first member  76  that is formed to fit onto a second member  78 . The second member  78  can define the bone connection portion  80 , which can be any appropriate bone connection portion, including those discussed above, such as the tapered spike  40  illustrated relative to the acetabular implant  30 . The second member  78  can also form a body portion  82  that is received or fits into a recess  84  formed in the first member  76 . The recess  84  can be substantially complementary to the body connection portion  82  to allow for appropriate fit. 
     The two members, including the first member  76  and the second member  78  can be formed separately to allow for the use of a different material for the two members. For example, the first member or articulating member  76  can be formed of a pyrolytic carbon, similar to that discussed above, to allow for articulation with the natural femoral head  26 . The properties of the pyrolytic carbon can allow for the articulation of the femoral head  26  with the acetabular implant  30   d  with low or no wear on the natural femoral head  26 . 
     The first member  76  can then be connected to the second member  78  with any appropriate mechanism, such as an interference fit, adhesives, snap fit, screw fit, taper connection, or the like. The connection of the first member  76  to the second member  78  allows the bone connection mechanism  80  to be formed using the properties of the second material of the second member  78  that may not be possible with the material properties of the first member  76 , such as pyrolytic carbon. For example, a thread or fixation configuration can be formed in the bone contact or fixation portion  80  that can provide additional holding power. For example, certain configurations (e.g. thickness, width) of the second member when formed of a metal may not be appropriate for fixation to bone when the second member is formed of the pyrolytic carbon material of the first member  76 . Although the combination of the first member  76  and the second member  78  can provide similar benefits of the substantially single or uniformly formed material members of the acetabular prostheses discussed and illustrated in  FIGS. 2A-2D . 
     With reference to  FIG. 3B , an acetabular implant  30   e  is illustrated. The acetabular implant  30   e  can include an articulation surface  32   e  similar to the articulation surface  32  illustrated and referenced to the acetabular implant in  FIG. 32A . The acetabular implant  30   e , however, can include a first member  86  and a second member  88 . The second member  88  can include a body portion  90  and a bone connection portion  92 . The second member  88  can also include a recess  94  that is configured and shaped to receive the first member  86  and the first member  86  can be connected to the second member  88  in a manner similar to that of the first member  76  to the second member  78 . This can allow the first member  86  to be formed of a separate material or different material than the second member  88 . The materials of the first member  86  and the second member  88  can be similar to the materials of the first member  76  and the second member  78  of the acetabular implant  30   d  illustrated in  FIG. 3A . Accordingly, the properties of the bone connection portion  92  can be provided based upon the material properties of the second member  88 , which may not be possible with the material properties of the first member  86 . Again, the first member  86  can be formed of a material to articulate with the natural femoral head  26 , such as pyrolytic carbon. Also, the bone connection portion  92  can be formed in any appropriate configuration, including those discussed above, such as interference fit, or a point or spike similar to the taper portion  40  illustrated in  FIG. 2A . 
     With reference to  FIG. 3C , an acetabular prosthesis  30   f  is illustrated. The acetabular prosthesis  30   f  can include a first member  96  and a second member  98 . The second member  98  can include a body portion  100  and a bone connection portion  102 . The body portion  100  can have a perimeter dimension that is substantially equivalent to a perimeter dimension of the first member  96 . The second member  98 , however, can be formed of a different material in the first member  96 . The first member  96  can then be adhered to the second member  98  with any appropriate mechanism, such as adhesives, welding, and the like. The perimeter dimensions that are substantially identical and complementary, allow for the first member  96  to substantially cover the second member  98 , but allows for a complete support of the first member  96  with the second member  98 . The second member  98  can be formed of a different material than the first member  96  and they can be adhered together using appropriate mechanisms, such as adhesives, welding, internal attachment mechanisms (e.g. projections  104  from the first member  96  that engages, in an interference fit with recesses  106  in the second member  98 ). 
     Accordingly, as illustrated in  FIGS. 3A-3C , it will be understood that the acetabular prostheses  30   d - 30   f  illustrate that a pyrolytic carbon articulation portion can be provided to articulate with the natural femoral head  26  while allowing for a second portion to be provided to fit within the acetabulum  22  of the patient. This allows the bone connection portions  80 ,  82 ,  102  to be formed of appropriate materials and selected mechanisms to fixedly hold the respective acetabular implants  30   d - 3   f  within the acetabulum  22 . The respective first members  76 ,  86 ,  96  can be fixed to the respective second members  78 ,  88 , and  98  with appropriate mechanisms including interferences fits, adhesives (e.g. bone cement), and other fixation mechanisms. 
     With reference to  FIG. 4A , an acetabular prosthesis  110  is illustrated. The acetabular implant  110  can be formed to include a porous metal bone fixation portion  112  and an articulation portion or surface  114 . The articulation surface  114  can be formed of appropriate materials, such as highly polished metals, including cobalt chrome alloys, or non-metal materials such as pyrolytic carbon. As discussed above, pyrolytic carbon can be used for articulation substantially with the natural femoral head  26  when the acetabular implant is positioned in the acetabulum  22 . 
     The bone fixation portion  112  that can be formed of a porous metal that can allow for bone ingrowth for fixation of the acetabular implant  110 . Porous metal portions can include Regenerex™ sold by Biomet, Inc. The porous metal bone fixation portion  112  can define substantially an entire surface of the acetabular implant  110  for fixation in the acetabular  22 . The articulation surface  114  can be similar to the articulation surface  32 , as discussed in relation to the acetabular implant  30  in  FIG. 2A . Accordingly, the articulation surface  114  can be substantially concave to fill a void or defect in the acetabular cartilage  24 . The pyrolytic carbon or other material used to form the articulation surface  114  can be mated to the porous metal portion  112 . The articulation surface  114  can be mated to the porous metal portion  112  by interdigitation of the articulation surface into the porous metal portion  112 , adhesives, or similar fixation mechanisms. Thus, the acetabular implant  110  can be integrated as one-piece for implantation into the acetabulum during an operative procedure. The articulation surface  114  can be substantially polished to allow for smooth articulation of the femoral head  26 . 
     With reference to  FIG. 4B , an acetabular prosthesis  120  is illustrated that includes a bone attachment portion  122  that can include a bone piercing region  124  (e.g. spikes, barbs, etc.) and a bone contacting region  126 . The bone piercing and bone contacting regions  124 ,  126  can be formed of a porous metal, such as a Regenerex™ sold by Biomet, Inc. The porous metal can allow for boney ingrowth to form a selected and long term fixation of the acetabular prosthesis  120  relative to the acetabulum  22 . 
     An articulation surface  128  can be formed on the acetabular prosthesis  120  and can be formed of materials for articulation with the femoral head  26 . For example, the articulation surface  128  can be metal alloys, such as cobalt chromium alloys, that are highly polished. Alternatively, the articulation surface  128  can be pyrolytic carbon to allow for articulation with the natural femoral head  26  and substantial reduction or elimination of possible wear of the femoral head  26 . 
     The acetabular implant  110 ,  120  illustrated in  FIGS. 4A and 4B  can allow for fixation to the acetabulum  22  in the pelvis  20  using the porous ingrowth properties of the porous metals. Porous metals allow for ingrowth throughout a volume of the bone fixation regions  112 ,  122  for long term fixation of the acetabular implants  110 ,  120  relative to the pelvis  20 . In addition, the acetabular implants  110 ,  120  can be formed to fill the defect  25  in the acetabular cartilage  24  that does not fill the entire acetabulum  22  of the patient. 
     With reference to  FIG. 5A , an acetabular implant  130  is illustrated. The acetabular implant  130  can be any of the acetabular implants illustrated and discussed in  FIGS. 2A-4B . The acetabular prosthesis  130 , however, can include a bone fixation region  132  that has a central or long axis  134  that forms an angle  136  relative to a body or contacting surface  138  of a body portion  140  of the acetabular prosthesis  130 . The body portion  140  can include a dimension, such as an edge to edge dimension  142  and a central axis  144  that generally divides the dimension  142  in half. The acetabular prosthesis  130  can also include an articulation surface  146  to articulate with the femoral head  26 . 
     The angle  136  can allow for a selected position of the acetabular prosthesis  130  in the acetabulum and for selected fixation properties. For example, the acetabular prosthesis  130  can be driven at an angle into the acetabulum  22  to allow for fixation of the acetabular prosthesis  130  within the acetabulum  22  once the femoral head  26  is positioned back into the acetabulum  22  and articulates with the acetabular prosthesis  130 . The angle  136  can allow for a pressure or force to be applied to the acetabular prosthesis  130  generally along the axis  134  after the femoral head  26  is positioned back into the acetabulum  22 . In one example, the defect  25  may be in a position in the acetabulum  22  where the angle  136  of the bone fixation region  132  can be aligned with a natural axis of force from the femoral head  26  once the femur is placed back into the acetabulum  22 . The axis of force of the femur may be the vertical axis or inferior-to-superior axis of force through the femoral head  26  to the acetabulum  22 . The angle  136  can be selected and formed in the acetabular prosthesis  130  according to the location of the defect  25  and the anatomy of the patient. Accordingly, it will be understood that the angle  136  can be formed based upon a particular anatomy of the patient and the position of the defect  25  relative to the acetabulum  22 . 
     With reference to  FIG. 5B , an acetabular prosthesis  150  is illustrated. The acetabular prosthesis  150  can include a bone connection region  152  that substantially defines a long axis or axis  154  that can form an angle  156  with a bottom surface  158  of a body portion  160  of the acetabular prosthesis  150 . A cross dimension  162  can define a distance from edge to edge of the acetabular prosthesis  150  and an axis  164  can generally divide the distance  162  in half. As illustrated in  FIG. 5B , the axis  154  of the bone fixation region  152  need not intersect the dividing axis  164  at the bottom surface  158  of the body region  160 . Accordingly, the bone fixation region  152  may be offset from a center of the acetabular prosthesis  150  for fixation into the acetabulum  22 . 
     The positioning of the bone fixation region  152  can allow for positioning of the acetabular prosthesis  150  into the acetabulum and for maintaining fixation of the acetabular prosthesis  150  and into the acetabulum  22 . Again, based upon the anatomy of the patient, the femoral head  26  articulates with an articulation surface  166  and the pressure of the femoral head  26  against the articulation surface  166  can assist in holding the acetabular prosthesis  150  in the acetabulum  22 . The offset distance or position of intersection of the axis  154  of the bone connection region  152  with the dividing axis  164  can be selected based upon the position of the acetabular prosthesis  150  within the acetabulum  22  and the remaining anatomy, such as the configuration and placement of the femoral head  26  within the acetabulum  22 . The selected position can assist in fixation and maintaining a fixation position of the acetabular prosthesis  150  once positioned in the acetabulum  22 . The angle  156 , amount and position of the offset, and other features or positions of the bone fixation portion  152  can be selected for applying a force along the axis  154  similar to the fixation types as discussed in relation to the acetabular prosthesis  130 . 
     With reference to  FIGS. 6A-6D , acetabular prosthesis, according to various embodiments can be included in selected shapes. As illustrated in  FIGS. 6A-6D , a plurality of shapes can be provided, and those exemplarily illustrated are provided for illustration purposes only. Accordingly, an acetabular prosthesis can be included in appropriate shapes including substantially circular shapes illustrated above and the irregular or regular geometric shapes illustrated in  FIGS. 6A-6D . 
     In particular, an acetabular prosthesis  170 , illustrated in  FIG. 6A , can include an oval shape. Accordingly, the acetabular prosthesis  170  can include a minor axis  172  and a major axis  174 . The minor and major axes  172 ,  174  can be selected based upon the size of the defect  25  in the acetabulum  22 . It will be understood that the shape and size of the acetabular prosthesis can be selected preoperatively using various techniques, such as exploratory surgery or imaging, or can be provided in a kit of a plurality of sizes and dimensions to be selected by a user during an operative procedure. Nevertheless, an oval exterior perimeter  176  can be provided to fill a selected defect shape. 
     With reference to  FIG. 6B , an acetabular prosthesis  180  is illustrated to have rectangular perimeter  182 . The perimeter  182  can include a long side  184  and a short side  186 . Although  FIG. 6B , illustrates a substantially regular rectangle, it will be understood that a trapezoid or other irregular shapes can also be provided. Similarly, a square can be provided with equal length sides. 
     With reference to  FIG. 6C , a partial circle or oval and convex acetabular prosthesis  190  is illustrated. The acetabular prosthesis  190  can include a first portion  192  that has a small radius and a second portion  194  that has a large radius. The large radius portion  194  can be substantially convex in the acetabular prosthesis  190 . It will be understood, however, as illustrated in  FIG. 6D , that a second portion  200  having a large radius can form a substantially concave region or portion of an acetabular prosthesis  202 . The acetabular prosthesis  202  can include the first portion  192  that is substantially similar in radius to the first portion  192  of the acetabular prosthesis  190 . Thus, a concave or a convex configuration can be formed for the acetabular prosthesis as selected. 
     As illustrated in  FIG. 7 , an irregularly shaped acetabular prosthesis can be used to fill the acetabulum  22  in various irregular shapes and/or substantially along an edge of the acetabulum  22 . For example, as illustrated in  FIG. 7 , the acetabular prosthesis  190  can have the first portion  192  that extends into the acetabulum and the second portion  194  that is generally positioned along the edge of the acetabulum  22 . Thus, the acetabular prosthesis, according to various embodiments, can be positioned on an edge of the acetabulum  22  and have a non-uniform shape to conform with the acetabulum  22 . 
     It will be understood that the acetabular prosthesis can be provided as one member or as a plurality within the acetabulum  22  of the patient. Thus, one or more of the acetabular prostheses can be provided in the acetabulum  22  to fill one or a plurality of defects  25 . For example, as illustrated in  FIG. 7 , a round acetabular prosthesis, such as the acetabular prosthesis  30 , can also be provided within the acetabulum  22 . Thus, a plurality of acetabular prosthesis can be provided in a single acetabulum  22  to fill multiple or a large defects without requiring replacement of the entire acetabulum, such as with an acetabular implant. 
     With reference to  FIGS. 8 and 9 , the acetabulum  22 , as generally understood by one skilled in the art, includes a labrum  210  that generally surrounds the socket and cartilage region  24 . The labrum  210  can be damaged through injury, use, age, and the like and a labrum prosthesis  220  can be used to replace a portion or all of the labrum  210 . The labrum prosthesis  220  can include a portion that defines a labrum portion  222  that extends out of the cartilage region  24  of the acetabulum  22 . Labrum implants can include those disclosed in U.S. patent application Ser. No. 12/915,366, filed on Oct. 29, 2010, published as U.S. Pat. App. Pub. No. 2012/0109328, incorporated herein by reference. The labrum prosthesis  220  can also include an articular cartilage region  224  extending into the region that generally articulates with the femoral head  26 . 
     The labrum prosthesis  220  can includes two regions where the labrum region  222  is convex and the acetabular cartilage region  224  is concave. The two differently shaped regions can allow the labrum implant  210  to be positioned to replace both a damaged region of the labrum and an adjoining damaged region of the acetabular cartilage region  24 . Thus, the labrum implant  210  can be provided to replace all appropriate damaged regions of the acetabulum  22  for articulation with the femoral head  26 . 
     The labrum prosthesis  220  can be formed of appropriate material such as pyrolytic carbon, including those discussed above. The pyrolytic carbon can be provided to articulate with the natural femoral head  26  with only minimal wear due to the properties of the pyrolytic carbon. Additionally, however, the labrum prosthesis  220  can be formed of other appropriate materials, including metals and metal alloys such as cobalt metal alloys. Metal alloys can be highly polished to articulate smoothly with natural anatomical portions, such as the femoral head  26 . 
     With reference to  FIGS. 10 and 11 , a labrum acetabular prosthesis  230  is illustrated. The labrum acetabular prosthesis  230  is exemplarily illustrated and substantially operable to replace an entire labrum portion of an acetabular region of the patient. It will be understood, however, that the labrum implant  230  can be sized to replace only a portion of the labrum and the acetabulum  22 , similar to the dimension illustrated in  FIGS. 8 and 9 . Nevertheless, the labrum prosthesis  230  can include a labrum portion  232  and an acetabular cartilage region  234 . The labrum acetabular prosthesis  230  can be fixed to the acetabulum  22  of the patient with a porous metal fixation portion  236 . 
     As illustrated in  FIG. 11 , the acetabular cartilage prosthesis portion  234  extends into the acetabulum  22  of the patient and replaces a portion of the natural cartilage  24  in the acetabulum  22 . The porous metal fixation portion  236  can be fitted against bone relative to the acetabulum  22  to allow for bone ingrowth and fixation of the labrum prosthesis  230 . The labrum portion  232  can then extend above or out of the acetabulum  22  to contact the femoral head  26  in a substantially natural limiting matter. Accordingly, the acetabular and labrum prosthesis  230  can include both the concave portion defined by the acetabular cartilage replacement portion  234 , and the convex portion defined by the labrum replacement portion  232 . Again, it will be understood that the labrum portion  232  can be formed of pyrolytic carbon as can the acetabular cartilage replacement portion  234 . The porous metal portion  236  can be fixed to the pyrolytic carbon portion in any appropriate manner, such as with adhesives, welding, or interdigitation by the pyrolytic carbon portions. 
     With reference to  FIG. 12 , the labrum and acetabular prosthesis can be fixed to the pelvis  20  with appropriate bone fixation portions, including a spike or projection  240 . The spike  240  can extend from a base plate  242  or from a bottom of a labrum and acetabular prosthesis  230 . Other fixation mechanisms can also be used, such as separate screws, barbs, rivets, etc. The base plate  242  can include a second projection or labrum engaging projection  244  to assist in fixation and stiffen of the labrum portion  232  of the labrum and acetabulum prosthesis  230 . The bone connection projections can be driven directly into the bone of the pelvis  20  or can be fitted into pre-drilled or pilot holes in the pelvis  20 . It will be understood that additional fixation mechanisms can be provided, such as adhesives (e.g. bone cement) to allow for initial or permanent fixation of the acetabulum and labor prosthesis  230 . 
     It will be understood that the acetabular prosthesis or the acetabular labrum prosthesis can be provided in appropriate dimensions based upon defects in the patient to be replaced. Additionally, a kit including two or more of the different types of acetabular prostheses, sizes of the acetabular prostheses, or shapes of the acetabular prostheses, or labrum acetabular prosthesis can also be provided. Accordingly, during an operative procedure, a user, such as a surgeon can determine or select an appropriately sized prosthesis for filling a determined or formed defect in the acetabulum  22  of the patient. Alternatively, or in addition to providing a plurality of prostheses in a kit, preoperative planning can be used to identify the appropriate size, shape, and type of prosthesis that can be selected for a selected procedure. The preoperative planning can include imaging or exploratory surgery of the patient to investigate the acetabulum  22  of the patient to identify the defect  25  in the acetabulum  22  to replace with an appropriate prosthesis. Accordingly, it will be understood that one or more of the prostheses can be provided during a single operative procedure and one or more of the prostheses can be selected to be put into the acetabulum  22  to treat one or more defects in the acetabulum  22 . 
     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.