Abstract:
A joint implant assembly including a spherical shaped component adapted to securing to an end of a first joint defining bone and a recess shaped component adapted to securing to an end of a second joint defining bone. Each of the components establishes an opposing wear surface, at which microscopic sized particles build up over time resulting from prolonged use of the joint. At least one of the spherical and recess shaped components exhibits a plurality of interior entrapment chambers, each of which including a narrow-most entranceway location communicating with the wear surface. The entrapment chambers further exhibit outwardly widening capture profiles extending within the associated component for securing volumes of the microscopic particles away from a zone defined between the wear surfaces.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This Application claims the benefit of U.S. Provisional Application 61/825,551 filed on May 21, 2013. This Application is a Continuation-in-part of application Ser. No. 12/776,903 filed on May 10, 2010. application Ser. No. 12/776,903 claims the benefit of U.S. Provisional Application 61/183,736 filed on Jun. 3, 2009. application Ser. No. 12/776,903 is a Continuation-in-part of application Ser. No. 12/266,695 filed on Nov. 7, 2008. application Ser. No. 12/266,695 claims the benefit of U.S. Provisional Application 60/986,486 filed on Nov. 8, 2007, the contents of which are incorporated herein in their entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to artificially implantable knee and hip joint assemblies. More specifically, the present invention discloses a variety of implant architectures in which an articulating and inter-abrading profile established between a ball and seat interface includes a plurality of individual debris collection chambers for facilitating secure removal of such as microscopic sized particles and shavings resulting from the articulating motion established between the ball and seat, the composition of which including any of a variety of different materials. 
       BACKGROUND OF THE INVENTION 
       [0003]    The prior art is documented with numerous examples of artificial implant assemblies, such as which are constructed in the attempt to facilitate ease of articulation as well as to reduce long term wear. Examples of such implants include the wear reducing acetabular component of Serbousek U.S. Pat. No. 5,916,269 and prosthetic component of Chan, U.S. Pat. No. 6,866,685, each of which incorporate interruptions in the inter-articulating joint faces. Also noted is the passive lubricating prosthetic joint of Heinz, US 2007/0179613, along with the prosthesis constructions in Taylor, US 2007/0270975 and the ball joint or cap implant for an artificial hip joint depicted in Grundei U.S. Pat. No. 7,771,485. 
         [0004]    A further objective of such artificial implant assemblies is the attempt to remove or isolate debris resulting from abrading contact and associated wear between the articulating surfaces of the joint implant. An example of one such construction is depicted in the debris isolating prosthetic hip joint of Kwong, U.S. Pat. No. 5,702,483 and which, in relevant part, incorporates a capsule configured by first and second surface treatments and in turn defined by the acetabular and femoral components. Each of the surface treatments causes fibrous tissue to attach to the acetabular and femoral components such that any resulting debris particles resulting from wearing of the articulating surfaces is confined within the capsule. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention discloses a joint implant assembly including a spherical shaped component adapted to securing to an end of a first joint defining bone and a recess shaped component adapted to securing to an end of a second joint defining bone. Each of the components establishes an opposing wear surface, at which microscopic sized particles build up over time resulting from prolonged use of the joint. 
         [0006]    At least one of the spherical and recess shaped components exhibits a plurality of interior entrapment chambers, each of which including a narrow-most entranceway location communicating with the wear surface. The entrapment chambers further exhibit outwardly widening capture profiles extending within the associated component for securing volumes of the microscopic particles away from a zone defined between the wear surfaces. 
         [0007]    The implant assembly further includes at least one of a hip or knee joint assembly, in the instance of a hip joint, the assembly further exhibiting a concave shaped seat articulating relative to a spherical shaped ball mounted atop an affixing stem. In the instance of a knee joint, the assembly further exhibiting a concave seat attached to a pedestal supporting stem exhibiting debris capture architecture integrated into each of first and second lateral recessed locations, against which seat opposing and substantially spherical portions associated with an inter-articulating implant component forming a further portion of the knee joint assembly. 
         [0008]    The entrapment chambers can further be constructed with any of individual pluralities of circular cross sectional profiles, continuous perimeter extending and coaxially spaced apart boundary profiles, angularly bisecting grid profiles, and ring shaped capture profiles. The spherical and recessed components can also constructed of at least one of a metal, plastic, ceramic or composite thereof. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    Reference will now be made to the attached drawings, when read in combination with the following detailed description, where in like reference numerals refer to like parts throughout the several views, and in which: 
           [0010]      FIG. 1  is a perspective view of a concave seating component forming a portion of a hip joint implant assembly according to a first embodiment and which incorporates a first version of a debris collection architecture for removing microscopic shavings and particles from an inter-abrading and progressive wear profile established between the seat and an opposing ball; 
           [0011]      FIG. 2  is a plan view in cutaway of a spherical or ball shaped component and an opposing and inter-articulating concave seat such as depicted in  FIG. 1 ; 
           [0012]      FIG. 3  is an enlarged partial view taken from  FIG. 2  and better showing the configuration of the integrally formed and individual debris collection chambers defined in the concave seat, such including narrow-most entranceway locations communicating with the abrading wear zone, the individual collection chambers further exhibiting outwardly widening capture chambers extending in a generally outward radial fashion toward a metal substrate layer affixed to the concave seat; 
           [0013]      FIG. 4  is a perspective view of a spherical or ball component forming an opposing portion of a hip joint implant assembly according to a second embodiment and which incorporates another version of a debris collection architecture form incorporated into an inter-abrading and progressive wear profile established with an opposing concave seat; 
           [0014]      FIG. 5  is a plan view in cutaway of the ball in  FIG. 4  in combination with a solid (non-apertured) concave seat; 
           [0015]      FIG. 6  is an enlarged partial view of  FIG. 5  and better showing the configuration of the integrally fowled and individual debris collection chambers defined in the spherical ball, such including narrow-most entranceway locations arranged at the abrading wear zone, with outwardly widening capture chambers extending toward a supporting stem to which the ball is affixed; 
           [0016]      FIG. 7  is a plan view in cutaway of a concave seat component forming a portion of a knee joint implant according to a further embodiment and which exhibits a similar debris capture architecture integrated into each of first and second lateral recessed locations against which seat opposing and substantially spherical portions associated with an inter-articulating implant component; and 
           [0017]      FIGS. 8A-8D  depict in perspective a series of non-limiting examples of concave seating components, such as shown in  FIG. 7 , with each exhibiting a varying debris entrapment profile. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0018]    As previously described, the present invention is directed to a variety of artificially implantable knee and hip joint assemblies, incorporating a variety of implant architectures. As will be further described in detail with regard to the following embodiments, the present invention focuses on an articulating and inter-abrading profile established between such as a ball and seat interface, in which progressive wear results in aggregation of microscopic sized debris particles (such as metal or plastic shavings). The ability to remove even a percentage of microscopic debris and particles from the inter-articulating wear zone defined between the articulating ball and concave seat, such as through the architectural design of the individual debris collection chambers as will be described in additional detail with reference to the succeeding illustrations, provides such artificial implants with greatly extended useful life and concurrent comfort to the patient. 
         [0019]    Referring to  FIG. 1 , a perspective view is generally shown at  10  of a concave seating component forming a portion of a hip joint implant assembly according to a first embodiment. The component can include any material not limited to a plastic, metal or composite (it being understood that it is desirous in many instances to establish a wear profile between two different materials including plastic on metal but which can also envision plastic on plastic or metal on metal wear interfaces). In one non-limiting application the concave seating component  10  can include a first material (a polypropylene or other plastic), with an opposing ball or spherical component  12  (such as mounted to a stem  14  as shown in  FIGS. 2-3 ) being constructed of a second alternating material (e.g. a titanium or other metal, ceramic or other suitable construction). 
         [0020]    Although not further shown, it is understood that the ball and seat elements associated with each of the hip joint variants of  FIGS. 1-3  and  4 - 6 , as well as the knee joint variant of  FIGS. 7-8 , are implanted in situ into reconditioned end surfaces of opposing bones during a suitable medical implantation procedure. Without limitation, it is further understood that the debris collection architecture as further described below can be incorporated into any wear profile associated with a joint assembly not limited to those specifically described and illustrated herein. 
         [0021]    Referring to  FIGS. 1-3  collectively, a first version of a debris collection architecture includes a plurality of individual entrapment or capture chambers which are formed into the architecture of the concave seat and between an inner seating surface  16  and an outer (convex) surface  18  (these defining a generally consistent wall thickness further referenced by outer rim  19  in  FIG. 1 ), over which in turn is mounted a substrate layer  20  ( FIG. 2 ) such as a metal or other suitable material which defines an inner base support of the concave seat and which can be anchored or otherwise secured to a reconditioned recessed profile formed within the associated joint defining bone). As best shown in  FIG. 3 , the architecture of the individual entrapment chambers is further described and includes narrow-most entranceway locations (see circular or other polygonal cross sectional shaped profiles at  22 ,  24 ,  26 , et seq. in  FIG. 3 ) at the abrading wear zone, with outwardly widening capture profiles extending in a generally outwardly radial fashion toward the metal substrate layer  20  (see further at  28 ,  30 ,  32 , et. seq.) affixed to the concave seat. 
         [0022]    In this manner, the microscopic particles and shavings (e.g. metal or plastic) which are not shown but which are understood as inevitably resulting from the constant combined articulating and frictional/rubbing motion established between the spherical or ball shaped component and opposing concave seat component are usually of a microscopic dimension, thus enabling them to captured or retained within the narrowed openings  22 - 26  of the entrapment chambers, with additional captured particles gradually building up within each chamber toward the widened (outer) ends  28 ,  30 ,  32 . It is further understood that the dimensions, shaping or other number of debris/particle capture chambers can be adjusted (such as from a generally conical shaped as generally depicted) and in order to adapt to varying operational parameters associated with the joint. These considerations can include without limitation the type of joint, the composition of the materials employed in the opposing components, and the anticipated size of the inevitable debris/particles which will be created within the joint/wear zone. 
         [0023]      FIGS. 4-6  illustrate a reverse embodiment as compared to  FIGS. 1-3 , see as generally shown at  34  in  FIG. 4 , and in which the debris capture architecture is configured within a redesigned ball or sphere forming a portion of a hip joint implant assembly according to a second embodiment. As with the first embodiment, a plurality of integrally formed and individual debris collection chambers are defined in the spherical ball, these best depicted in the enlarged cutaway of  FIG. 6  and including narrow-most entranceway locations  36 ,  38 ,  40 , et seq. at the abrading wear zone established with a surrounding concave seat  42 , with outwardly widening capture chambers  44 ,  46 ,  48 , et. seq. extending toward the stem  14  to which the ball is affixed. 
         [0024]    Also, and as with the initial embodiment of  FIGS. 1-3 , the individual debris entrapment chambers can be distributed in any desired spatial manner across either or both of the opposing and inter-articulating convex and concave surfaces associated with the ball/sphere and seat, respectively. This can further include varying the number and distribution of the entrapment chambers, as well as additionally or alternatively varying the size or dimension of the debris isolation chambers (such further contemplating having both smaller and larger sized chambers arranged in an inter-mixed fashion in order to better capture and remove a desired percentage of the microscopic sized wear debris or particles). 
         [0025]    It is also envisioned that subset numbers of the debris capture or isolation chambers can vary in other manners not limited by the present description and which can be designed to enhance ongoing and continues particle debris removal over the life of the artificial implant. Otherwise, the embodiment of  FIGS. 4-6  operates identically to that previously described in  FIGS. 1-3 , with the exception that the progressive debris entrapment occurs along the inter-articulating surface of the ball/sphere  34  in  FIG. 4 , and as opposed to occurring at the concave seat  10  of  FIG. 1 . 
         [0026]    Referring to  FIG. 7 , a plan view in cutaway is shown of a concave seat component  50  (this as shown attached to a pedestal supporting stem  52  which can be anchored into a reconditioned bone end) and forming a portion of a knee joint implant according to a further embodiment. As depicted, the seat component  50  exhibits a similar debris capture architecture integrated into each of first and second lateral recessed profiles or locations, see at  54  and  56  and against which seat opposing and substantially spherical or convex shaped portions (generally depicted at  53  with convex surfaces  55  and  57  in spatially arrayed fashion relative to the concave seat component  50 ) associated with an inter-articulating implant component forming a further portion of a knee joint assembly. The captures pockets referenced in  FIG. 7  are shown extending to a supporting surface of a planar base component  59  formed with the stem  52 , it being understood that the depth and shape of each capture pocket (such as which are defined by any of an inner sleeve shape or other closed polygonal, arcuate or circular cross sectional profile defined in the concave seat or ball) can vary without shape or limitation. 
         [0027]    Finally, and referencing  FIGS. 8A-8D , depicted are a series of non-limiting examples of concave seating components, such as shown in  FIG. 7 , with each successive seating component exhibiting a varying debris entrapment profile. These include, initially referring to  FIG. 8A , a first variant  58  in which individual pluralities of debris entrapment chambers  60  and  62  similar to those previously depicted are formed into each of the laterally arrayed and recessed (or pseudo-concave) seating surfaces (corresponding to those shown at  564  and  56  in the variant of  FIG. 7 ) and which again include narrowed diameter inlet locations proximate the joint wear interface for admitting or capturing the microscopic sized wear particles, with communicating and widening capture pockets extending inwardly into the body of the supporting component for securely retaining the volumes metal or plastic wear particulate. 
         [0028]      FIG. 8B  depicts the variant shown at  50  in  FIG. 7  and in which the entrapment chambers extend as continuous perimeter extending and generally concentrically spaced apart and individually perimeter defining and enclosing boundaries, see individual pluralities  64 ,  66 ,  68 , et seq. and  70 ,  72 ,  74 , et seq. respectively defined in the exposed and laterally arrayed and recessed/concave support surfaces of the seat  50 . The concentric profile shown can include any of generally circular shaped or, as depicted, modified arcuate profiles. 
         [0029]      FIG. 8C  depicts a yet further variant  76  in which angularly bisecting grid patterns, see individual pluralities of generally grid intersecting slots as depicted at  78 ,  80 ,  82 , et seq. and  84 ,  86 ,  88 , et seq. for each associated recessed concave seating surface, are respectively integrated into recessed support surfaces  90  and  92 . Finally,  FIG. 8D  depicts an additional and non-limiting variant  94  in which pluralities of ring shaped capture profiles are defined at  96 ,  98 ,  100 , et. seq. and  102 ,  104 ,  106 , et. seq., in each of first and second recessed support surfaces  108  and  110 . As further shown, the ring shaped entrapment chambers are shown in an intercommunicating arrangement along selected and arcuate extending boundary locations, it being understood that some or all of the profiles can be segregated or isolated in any fashion desired. 
         [0030]    Having described our invention, other and additional preferred embodiments will become apparent to those skilled in the art to which it pertains, and without deviating from the scope of the appended claims.