Abstract:
A pressurizable implant, comprising a body and at least one porous arm extending from and interconnected to the body, the at least one porous arm being configured to accommodate a pressure gradient that is created by a device removably connectable to the body.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is related and claims priority to U.S. Provisional Patent Application Ser. No. 61,533,374 filed on Sep. 12, 2011, the complete and entire disclosure of which is hereby expressly incorporated by reference herein. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention generally relates to a pressurizable implant, at least a portion of which may be composed of a porous or mesh-like material, and more specifically to an implant adapted to create a pressure differential that is configured to encourage tissue ingrowth and/or to allow materials such as medicines, antibiotics, growth factors and blood platelets to be introduced at or around the implantation site. 
       BACKGROUND OF THE INVENTION 
       [0003]    To promote and encourage the ingrowth of surrounding bony and soft tissues, biomedical implants sometimes contain one or more porous surface. In essence, these surfaces function as scaffolds, which provide desirable load-bearing strength at the implantation site as a result of the ingrown tissue. 
         [0004]    While many implants have surfaces conducive to bony ingrowth, the depth of ingrowth penetration associated with these devices is not only limited by various biological factors, but is also limited by the fact that the ingrowth must be achieved without mechanical assistance. Moreover, in addition to promoting bony and soft tissue ingrowth, porous implants may also undesirably introduce microbes and metabolic agents into the implantation site, thereby increasing the potential for an infection to develop. Not only is the risk of infection increased, but the presence of toxins, wound drainage fluid and other substances within the implantation site may further hinder the positive effects of the ingrowth if they become trapped inside the porous material. 
         [0005]    To minimize the increased threat of infection, biological pressure gradients are sometimes utilized during the surgical process. These pressure gradients not only enhance post-surgical recovery and healing (e.g., by assisting with wound closure and the application of suction forces for draining bodily fluids and exudates), but they also directly counter the onset of infectious conditions. Finally, they may also be used to irrigate wound sites by infusing them with pharmacological agents, such as medicines, antibiotics, growth factors and blood platelets. 
         [0006]    The present invention is intended to improve upon and resolve some of these known deficiencies of the art. 
       SUMMARY OF THE INVENTION 
       [0007]    In accordance with one aspect of the present invention, a pressurizable implant is provided and comprises a body and at least one porous arm extending from and interconnected to the body. The at least one porous arm is configured to accommodate a pressure gradient that is created by a device removably connectable to the body. 
         [0008]    In accordance with another aspect of the present invention, a system for pressurizing an implant is provided. According to this aspect of the invention, the system comprises a body having an internal chamber, at least one porous arm extending from and interconnected to the internal chamber via a channel or duct, an airtight seal, and a device configured to removably couple to the airtight seal to distribute a pressure gradient across the at least one porous arm. 
         [0009]    In accordance with still another aspect of the present invention, a method of distributing a pressure gradient across an implant during a surgical procedure is provided. According to this embodiment, the method comprises the steps of providing an implant having a body, an internal chamber and at least one porous arm extending from and interconnected to the internal chamber via a channel or duct; placing an airtight seal in the internal chamber; connecting a device to the airtight seal; and actuating the device to create a pressure differential across at least a portion of the implant. 
         [0010]    Other objects and benefits of the invention will become apparent from the following written description along with the accompanying figures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The above-mentioned aspects of the present invention and the manner of obtaining them will become more apparent and the invention itself will be better understood by reference to the following description of the embodiments of the invention taken in conjunction with the accompanying drawings, wherein: 
           [0012]      FIG. 1  is a perspective view of a pressurizable implant in accordance with the teachings of the present invention; 
           [0013]      FIG. 2  is a front, cross-sectional view of the pressurizable implant taken along line  2 - 2  of  FIG. 1 ; 
           [0014]      FIG. 3  is a front, cross-sectional view of another pressurizable implant in accordance with the teachings of the present invention; 
           [0015]      FIG. 4  is a cross-sectional view of an implanted pressurizable implant in accordance with the teaching of the present invention, the implant accommodating a pressure gradient as a user actuates a syringe connected to the implant; 
           [0016]      FIG. 5  is a front, cross-sectional view of a pressurizable implant in accordance with the present invention and having a humeral head component that is to be fitted into the implant during implantation; 
           [0017]      FIG. 6  is a front, cross-sectional view of the pressurizable implant of  FIG. 5  after the humeral head component has been fitted into the implant; and 
           [0018]      FIG. 7  is a cross-sectional view of a patient&#39;s shoulder having a pressurizable implant in accordance with the teachings of the present invention implanted therein together with a humeral head component. 
       
    
    
     DETAILED DESCRIPTION 
       [0019]    The embodiments of the present invention described below are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may appreciate and understand the principles and practices of the present invention. 
         [0020]    Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any method and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the specific methods and materials are now described. Moreover, the techniques employed or contemplated herein are standard methodologies well known to one of ordinary skill in the art and the materials, methods and examples are illustrative only and not intended to be limiting. Furthermore, while the present teachings for the disclosed pressurizable implant are sometimes described in association with a humeral head component and shoulder prosthesis, those skilled in the art will appreciate that the present teachings may be incorporated into various other orthopedic implants for a human body such as knee, hip, and other joints. Therefore, it is to be understood that the present illustrative embodiments are not meant to limit the present invention. 
         [0021]    The following detailed description, beginning with  FIG. 1 , illustrates a pressurizable implant device constructed in accordance with the present teachings and generally identified by reference numeral  10 . The pressurizable implant  10  is generally defined by a housing or body  12  that has an inner surface  14  and an outer surface  16 . A plurality of arms or fins  18  are arranged around the outer surface  16  of the body  12 , and, in accordance with certain embodiments, are formed entirely of a porous material that extends from the inner surface  14  of the body  12  to the outer surface  16 . In certain specific embodiments, the porous material is comprised of a metal selected from one or more of stainless steel, titanium, titanium alloys, cobalt-chromium alloys and other materials that are suited for use in a biocompatible environment. While it should be understood and appreciated herein that the body  12  of the implant  10  may also be formed of a porous material, in accordance with certain aspects of the present invention, the body  12  is at least partially formed of a non-porous material, such as stainless steel, titanium, titanium alloys, cobalt-chromium alloys and other materials that are suited for use in a biocompatible environment. It should also be understood and appreciated herein that the size and shape of the implant can depend on the specific implantation procedure being conducted on the patient. In certain embodiments, however, the body  12  is cylindrical and has an opening at its top to accommodate an internal chamber  20 . 
         [0022]    Referring now to  FIG. 2 , a front, cross-sectional view of the pressurizable implant  10  taken along line  2 - 2  of  FIG. 1  is shown. As can be appreciated from this illustration, the arms or fins  18  are interconnected to the internal chamber  20  of the body  12  by way of one or more channels or ducts  22 . It should be understood herein that those of skill in the art can vary the specific size, number and orientation of the associated channels or ducts  22 , particularly as these properties will largely be dependent upon the specific implantation procedure being performed. However, as will be discussed below, in accordance with certain aspects of the present invention, the channels or ducts  22  are sized so that they accommodate and facilitate the ingrowth of surrounding bony and soft tissues by allowing a pressure gradient to be created and distributed across the implant. In accordance with certain specific aspects of the present invention, the average pore size of the disclosed porous material may be from about 100 microns to about 700 microns, and the average porosity may be from about 40% to about 80%. 
         [0023]      FIG. 3  shows a front, cross-sectional view of another pressurizable implant  10  in accordance with the present invention. In accordance with this alternative aspect of the present invention, the plurality of arms or fins  18  are formed of a porous material, as well as include a series of branched channels  24  that extend from the inner surface  14  of the body  12  to the outer surface  16 . In certain specific embodiments, the porous material is comprised of a metal selected from one or more of stainless steel, titanium, titanium alloys, cobalt-chromium alloys and other materials that are suited for use in a biocompatible environment. While it should be understood and appreciated herein that the arms or fins  18  of the implant  10  may be formed of a porous material, in accordance with certain aspects of the present invention, the arms or fins  18  may also be formed of a non-porous or partially porous material, wherein the branched channels  24  are etched or formed within the arms or fins  18  as desired. Those of skill in the art should understand and appreciate herein that one of the specific benefits of the branched channel configuration shown in  FIG. 3  is that the channels  24  can be specifically designed to mimic the natural vascular shape and structure found within the human body. In addition, because the branched channels  24  can be designed to mimic specific orientations, it is possible to isolate where pharmacological agents are delivered into the body relative to these channels. To design the channels  24  in accordance with the teachings of the present invention, those of skill in the art will understand that known techniques such as additive manufacturing processes can be used. 
         [0024]    With reference to  FIG. 4 , the arms or fins  18  of the present invention are configured to create and distribute a pressure differential or gradient by way of a device that is capable of altering the associated pressurization properties of the implant  10 . Here, the implant device  10  is placed inside a humerus  40  as part of a shoulder procedure, and a syringe  30  is connected to the implant  10  device by way of a tube  32 . To create and distribute a negative pressure gradient across the implant  10 , a seal  34  (e.g., a rubber stopper or similar device) is placed inside or on top of the internal chamber  20  so that it seals against the inner surface  14  of the body  12 , thereby creating an airtight seal. In turn, the tube  32  is advanced into a channel or bore that passes through the seal  34  and exits into the internal chamber  20 . When a user actuates the plunger  31  of the syringe  30  by pulling it upward, air within the chamber  20  and the arms or fins  18  is removed, evacuated or sucked from the implant  10 , thereby creating and distributing a negative pressure gradient across the implant  10  and its arms or fins  18 . This negative pressure gradient created across the implant system facilitates and encourages (into the implant and its porous arms), the ingrowth of surrounding bony and soft tissues. Moreover, in the negative pressure gradient mode, fluid, toxins, microbes and other metabolic or biologic components can be drained from the implantation site, thereby reducing associated infection risks, as well as promoting post-surgical healing. 
         [0025]    In addition to the negative pressure gradient mode, the present invention is also configured to create and distribute across the implant  10  a positive pressure gradient in accordance with certain embodiments. To create and distribute a positive pressure gradient across the implant  10 , a seal  34  (e.g., a rubber stopper or similar device) is placed inside the internal chamber  20  so that it seals against the inner surface  14  of the body  12 , thereby creating an airtight seal. In turn, a tube  32  is connected to a syringe  30  and then advanced into a channel or bore that passes through the seal  34  and then exits into the internal chamber  20 . When a user actuates the plunger  31  of the syringe  30  by pushing it downward, liquid can be introduced into the chamber  20  and the arms or fins  18  and ultimately pushed out of the implant  10 , thereby creating and distributing a positive pressure gradient across the implant  10  and its arms or fins  18 . In a positive pressure gradient mode, the arms or fins  18  are configured to act as a manifold for distributing a pharmacological agent throughout the implantation site. In other words, the syringe  30  is capable of delivering a pharmacological agent through the airtight seal  34  and into the internal chamber  20 , where the agent can in turn leach out into the arms or fins  18  to displace bodily fluids and toxins occupying the interstitial spaces in the arms and fins  18 , thereby reducing or eliminating an environment in which microbes and metabolic products can develop and infect the implantation site. It should be understood and appreciated herein that various types of pharmacological agents can be used in accordance with the teachings of the present invention, including, but not limited to, one or more of medicines, antibiotics, growth factors and blood platelets. 
         [0026]    As mentioned above, the biological pressure gradients that can be created in accordance with the present invention not only enhance post-surgical recovery and healing (e.g., by assisting with wound closure and the application of suction forces for draining bodily fluids and exudates), but they also directly counter the onset of infectious conditions. Moreover, the pressure gradients may also be used to irrigate wound sites by infusing them with the various pharmacological agents discussed above. 
         [0027]    As is also mentioned above, the disclosed pressurizable implants of the present invention are intended to be useful for various orthopedic procedures, including, but not limited to, shoulders, knees, hips, and various other joints.  FIGS. 5-7 , for instance, illustrate the use of the pressurizable implant device  10  as part of a stemless shoulder system. In accordance with this illustration, a humeral head component  50  is fitted inside a top portion of the internal chamber  20  of the body  12 . In essence, the humeral head component  50  is shaped to fit into the same space that the airtight seal  34  would temporarily reside when a user is pressurizing the implant as described above. After the appropriate pressure gradient has been created and distributed across the implant, the humeral head component  50  is fitted into the implant (see  FIG. 6 ) and then surgically implanted into the humerus  40  as a pressurized shoulder prosthesis (see  FIG. 7 ). 
         [0028]    It should be understood and appreciated herein that while the present disclosure includes various embodiments showing the biological pressure gradients being created with a standard syringe device, other devices capable of achieving a negative and/or positive pressure gradient may also be used including, but not limited to, standard operating room suction devices, air pumping apparatuses, vacuum devices, etc. Accordingly, the present invention is not intended to be limited herein. 
         [0029]    It should also be understood and appreciated herein that in accordance with certain aspects of the present invention, it may be desirable to utilize a biological surface coating (e.g., a titanium porous plasma spray (PPS®) surface coating or a biomimetic coating (e.g., BoneMaster® coating), both of which are commercially available from Biomet), with the porous or nonporous surfaces to create a barrier to particulate debris (metallic, polyethylene or PMMA) and/or to further promote and increase the fixation of the bony ingrowth. 
         [0030]    While an exemplary embodiment incorporating the principles of the present invention has been disclosed hereinabove, the present invention is not limited to the disclosed embodiments. Instead, this application is intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.