Abstract:
A skeletal implant for replacing a human bone includes an inner reinforcing member and an outer plasticized and fluid resistant layer encasing the inner reinforcing member. A structurally rigid and foamable layer is disposed between the inner reinforcing member and the outer plasticized layer. An end of the outer layer is configured for receiving, in articulated engagement, an end of an adjoining bone. A plurality of ligaments are grafted between the implant and the adjoining bone and proximate the articulated engagement. Conduit passageways are also established between the inner reinforcing member and the end of the outer layer in order to communicate a fluid to an articulating engagement and ligament supporting location with an adjoining bone.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This Application is a Non-Provisional of Provisional (35 USC 119(e)) and claims the priority of U.S. Provisional Patent Application Ser. No. 60/949,051 filed on Jul. 11, 2007, entitled Skeletal Implant for Replacing a Human Bone. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention is a skeletal implant for use in replacing a human bone. In particular, the implant of the present invention is an improvement over prior art implants, typically those constructed of a metallic or other synthetic material, in that it provides for improved in-molding of ligaments (such as for attaching to existing bones) as well as over-molding at selected ends to provide additional support for such attachment, in addition to permitting the introduction of human-replicated fluids into the implant structure and to better assist in replicating the features of a human bone. 
       BACKGROUND OF THE INVENTION 
       [0003]    Prosthetic implants are well known in the art. Such include artificially installed hip joints and the like. 
         [0004]    A disadvantage of known implants includes the inadequate (or non-existent) use of ligaments to assist in incorporating the artificial bone implant into an effectively working component of a skeletal structure. In particular, existing prior art implants do not effectively address the need to incorporate an artificial implant (this replacing an existing/damaged natural bone or prior synthetic implant) in cooperating use with an existing bone, and such as by employing improved ligament connecting and/or lubricating structure in order to achieve a more effective and functional device. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention discloses a skeletal implant for replacing a human bone, and which is an improvement over prior art implants in that it provides for a more effective and dynamically interactive implant, such as when incorporated for use with existing/remaining bone structure. The implant includes an inner reinforcing member and an outer plasticized and fluid resistant layer encasing the inner reinforcing member. 
         [0006]    A structurally rigid and foamable layer is disposed between the inner reinforcing member and the outer plasticized layer. An end of the outer layer is configured for receiving, in articulated engagement, an end of an adjoining bone. 
         [0007]    A plurality of ligaments are grafted between the implant and the adjoining bone and proximate the articulated engagement. Conduit passageways are also established between the inner reinforcing member and the end of the outer layer in order to communicate a fluid to an articulating engagement and ligament supporting location with an adjoining bone. 
         [0008]    Additional features include the inner reinforcing member incorporating a metal insert. An inlet valve is further disposed upon the outer layer and communicates the fluid to at least the inner reinforcing member. The implant end also exhibits a three-dimensional and over-molded configuration, such as which may further include a plurality of alternating peaks and valleys and which, in cooperation with the ligament structure and fluid lubricant supply, ergonomically interact the implant with an existing bone. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    Reference will now be made to the attached drawings, when read in combination with the following detailed description, wherein like reference numerals refer to like parts throughout the several views, and in which: 
           [0010]      FIG. 1  is a cutaway illustration of a skeletal implant according to a preferred embodiment of the present invention; 
           [0011]      FIG. 2  is an enlarged end view illustration of the implant illustrated in  FIG. 1  and further showing the features of the over-molded end for attaching to an existing bone, fluid-holding reinforcement insert and externally attached ligaments; 
           [0012]      FIG. 2A  is an enlarged sectional illustration of the ligament structure of  FIG. 2  established between the skeletal implant and a connecting bone; 
           [0013]      FIG. 2B  is another enlarged sectional illustration of the reinforcing insert of  FIG. 2  which is capable of holding a volume of injected fluid; 
           [0014]      FIG. 3  is an enlarged end view illustration of a skeletal implant according to a further preferred embodiment of the present invention; 
           [0015]      FIG. 3A  is an illustration according to the prior art and which illustrates, in comparison to  FIG. 3 , an existing metal bone; 
           [0016]      FIG. 4  is a further illustration according to the prior art and which illustrates an existing bone-to-bone connection; and 
           [0017]      FIG. 5  is an illustration, similar in presentation to that shown in the prior art illustration of  FIG. 4 , and showing the over-molding of the skeletal implant end in order to provide additional support to the connection to such as an existing bone and according to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0018]    Referring now to  FIG. 1 , a skeletal implant is generally illustrated in cutaway at  10  according to a first preferred embodiment of the present invention. As previously described, the skeletal implant is intended to operate as a replacement for human bone structure (such as resulting from disease, accidents, etc.) and which is further an improvement over existing prosthetic metal implants and the like in that it provides a more effective implant, in particular when incorporated into a joint and ligament supported engagement with existing bone structure. 
         [0019]    The implant  10  includes the features of an internally positioned and reinforcing member  12 , the general configuration of which typically corresponds to that of the overall implant  10 . As shown in  FIG. 1 , the inner reinforcing member  12  is typically slightly less in overall dimension (accounting for the ergonomically configuring and ligament defining ends associated with the implant) and is also likely angled/contoured to match the desired overall configuration of the implant. 
         [0020]    In a preferred embodiment, the reinforcing member  12  is a metal reinforcing structure exhibiting a central elongated (and as described above typically a somewhat arcuate shaped) body. In the example illustrated, a plurality of scales  11  or other suitable shaped protuberances are defined along part (or all) of the overall length of the reinforcing member  12 , scales providing both reinforcing and positional stabilizing features to the inner reinforcing member  12 . It is also envisioned that a fluid  13  (such as which is consistent with that associated with normal human bones) can be encapsulated within the reinforced member and/or, as further discussed, also be supplied through a conduit passageway established with an open interior of the reinforcing member  12 . 
         [0021]    It is also envisioned that the reinforcing member  12 , in addition to being a metal such as an aluminum, can be constructed of other materials exhibiting the necessary properties of strength, weight, resiliency, fluid retention/sealing and durability, such as including certain types of plastics or polymers. In one instance, a molding process can be employed by which a powdered thermoplastic resin is formed into a defined shape. Such molding processes can include injection molding, compression molding, reaction injection molding (RIM), as well as other manual/cold molding/pouring processes. The result is a strengthened plastic composite which exhibits properties comparable to those of steel. 
         [0022]    Surrounding and encasing the reinforcing member  12  is an outer layer  14 , this including in one non-limited application such as an antimicrobial plastic material, the purpose of which is to assist in preventing the incidence of bacteria creation and/or infection, such as upon the implant  10  being inserted into the patient&#39;s body. Opposite end sections  16  and  18  of the outer layer  14  can further be constructed of a lubricated plastic composition, the purpose for which (as will be described in reference to succeeding figures) is to facilitate the ability of the ends of the implant  10  to smoothly and durably articulate in cooperation with end-engaging bones (either natural or implanted) in order to provide a maximum degree of comfort and motion. 
         [0023]    Encircling the three-dimensional space between the metal reinforcing member  12  and the outer plastic layer  14  is a plasticized foam  20  which operates to positionally secure and strengthen the construction of the implant, as well as the positional arrangement and retention of the inner reinforcing member  14  in a spatially supported fashion relative to the outer layer  14 . A number of materials are capable of being employed within the foam  20 , these again including any of the molding constructions previously described, and in addition to numerous other potential materials which can be used separately or in combination with a number of foamable plastic compositions. Along these lines, it is also envisioned that an aggregate composition can be incorporated into the foam  20 , such providing varying degrees of durability depending upon the desired implant performance parameters and/or desired application. 
         [0024]    Also illustrated at  22  is the provision of a valve, accessible to the open interior of the reinforcing member  12 , from the surface of the outer layer  14 , and which provides a fluid injection port (location) associated with the inner reinforcing member  12  and/or the encircling foam  20 . In this fashion, a fluid medium (not shown and which can include such as including a naturally reproduced bone fluid generated with natural bone structure) can be recycled for reuse. Other artificial fluids can also be substituted (or intermixed with a natural fluid) in order to provide varying performance characteristics to the implant and as will be subsequently described. 
         [0025]    Referring now to  FIG. 2 , a sectional cutaway end view illustration is shown of an implant  24 , similar to that illustrated in  FIG. 1 , and further showing the features of a composite plastic over-molded end  26  for encircling and receiving an opposing end of an existing bone  28 . In particular, the implant  24  includes a suitable central reinforcing member (or spline)  30  similar to that described in  FIG. 1 , and again within which is contained a volume of a suitable (nourishing and/or lubricating) fluid medium  32 . 
         [0026]    An end of the implanted reinforcing member  30  communicates with the over-molded/socket end  26  of the implant  24 , such as through communicating passages shown at  34 ,  36 , and  38  (see also enlarged view  FIG. 2B ) and, in this fashion, communicates the fluid medium  32  with a spacing  40  established between the socket end  26  and an opposing surface  42 , such as of the existing bone  28 . As previously stated, it is also envisioned that the implant construction of the present invention can be utilized singularly (such as in cooperation with existing human bone). Alternatively, the implant structure of the present invention is also envisioned to be capable of being provided in articulated pairs (such as upper arm/forearm or femur/lower leg arrangements). 
         [0027]    As again illustrated in  FIGS. 2 and 2A , a series of ligaments  44  extend between (such as outer edge) locations associated with each of the over-molded implant end  26  and the existing bone end  42 . The ligaments  44  can include both the natural variety of material (i.e., that harvested from actual bone and cartilage structure) as well as synthetically produced ligaments which can be implanted along with the skeletal implant structure. 
         [0028]    As further shown in  FIG. 2A , connecting end locations of the ligaments, see as shown at  45 , can be in-molded (or otherwise resistively inter-fitted or engaged) with end locations associated with the over-molded end  26  of the implant  24 . The ligaments  45  in this instance can potentially include natural ligaments associated with an existing bone for which it is desired to establish a substitute joint/socket arrangement with the newly substituted implant  24 . 
         [0029]    As is further known, ligaments are necessary for providing the necessary support and connection between adjoining bones, such as during the range of motion or pivoting of the bones within their socket connection. The ability to over-mold the socket end  26  of the implant  24 , such as which establishes multiple (individual) areas of contact, further provides additional support when engaged with the succeeding bone  28  (either natural or implanted). It is further understood that the over-molded end adopts a three-dimensional configuration which further includes a plurality of alternating peaks and valleys formed along said implant end. 
         [0030]    Referring now to  FIG. 3 , an enlarged end view illustration is shown of a skeletal implant  46  according to a further preferred embodiment of the present invention which includes an alternate variation of inner reinforcing member  48 , encircling foamed plastic layer  50 , and outer (fluid impervious and typically lubricous) composite plastic layer  52 . An additional fluid residing/impregnated layer is again shown at  54  and which, as previously described, can be constructed of a polymer or other composite plastic and which facilitates a range of motion when established in a joint defining relationship with a succeeding and articulating bone. 
         [0031]      FIG. 3A  is an illustration according to the prior art which illustrates, in comparison to  FIG. 3 , an existing metal bone  56 . The purpose of this illustration is to highlight the compositional differences of the implants, such as shown at  10 ,  24  and  46  of the present inventions, in comparison to an existing bone implant according to the prior art. 
         [0032]      FIG. 4  is a further illustration according to the prior art which illustrates an existing bone-to-bone connection as referenced by bones  58  and  60  with connecting ends  62  and  64  and associated ligaments  63 . The bone structure referenced in  FIG. 4 , is estimated as only capable of safely absorbing a minimal (e.g. no more than 50 lb) crosswise directed impact force, at which point the surface attached (non in-molded) ligaments are likely to pull away (disengage from) the attachment locations with each bone  58  and  60 . 
         [0033]    Referring finally to  FIG. 5 , an illustration, similar in presentation to the prior art view shown in  FIG. 4 , and which illustrates an implant  66  with an over-molded and interiorly configured  68  end, this in comparison to the bone  58  shown in the previous prior art illustration, the implant  66  establishing an articulating contact with the end  64  associated with existing bone  60  also referenced in  FIG. 4 . As previously described, the over-molding of the skeletal implant end, such as by the creation of individual and interconnected arcuate configurations  68 ,  70  and  72 , collectively define a recessed interior which interacts with the opposing end configuration  64  of the existing bone  60  to provide additional support to the sockete connection. 
         [0034]    Ligaments are again employed, and which are illustrated at  63 ′, these being similar to those shown at  63  in  FIG. 4 , with the exception that in-molding techniques can be employed (see further at  74 ) for more securely attaching ends of the ligaments to the implant  66 , such as which can extend naturally from the bone  60 . The implant  66  is otherwise constructed in a fashion similar to that described in reference to implants  10 ,  24  and  46 , such that a repetitive description is unnecessary. 
         [0035]    Having described my invention, other and additional preferred embodiments will become apparent to those skilled in the art to which it pertains, without deviating from the scope of the appended claims.