Abstract:
A vacuum package system for hydrating and/or rehydrating orthopedic graft materials, such as allograft materials, xenograft materials, and synthetic materials, is described. The system primarily includes a container, which includes a dividing device for dividing the container into first and second compartments and for isolating the compartments from one another, the first compartment containing a liquid component and the second compartment containing either dry porous and/or dehydrated orthopedic graft material under vacuum. An elongated pocket portion extends from, and is in communication with, the second compartment. A vacuum reservoir device is disposed within the pocket portion and is in communication with the second compartment. The vacuum reservoir device is capable of taking up substantially all residual interstitial gases and thereby ensuring thorough infusion of the liquid component into the orthopedic graft material component upon release of the dividing device so as to form either a hydrated and/or rehydrated orthopedic graft material. An optional gas permeable membrane is disposed between the second compartment and the pocket portion.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to orthopedic materials and packaging therefor, and more particularly to a device and method for hydrating and/or rehydrating orthopedic graft materials, such as allograft materials, xenograft materials, and synthetic materials. Specifically, a vacuum package system is provided for dehydrated, e.g., freeze-dried, orthopedic graft materials, as well as dry porous orthopedic graft materials, e.g., calcium-phosphate-based materials, which allows for liquid materials to rapidly and thoroughly infuse within the pores of either type of orthopedic graft material so as to form hydrated and/or rehydrated orthopedic graft materials. 
     BACKGROUND OF THE INVENTION 
     Allografting is one of the most widely used orthopedic transplantation techniques currently being used by orthopedic surgeons. Its main use is in the field of revision joint replacement, particularly total hip replacement, although its use is also widespread in the treatment of many different types of bone defects as well. 
     An allograft is generally defined as a graft of tissue, such as bone tissue, from a donor of one species and grafted into a recipient of the same species. Allograft tissue is typically derived from cadaveric donors (i.e., from deceased donors). 
     One type of allograft tissue is generally referred to as structural allograft tissue, which typically consist of blocks of bone or other types of tissue that can fastened to one or more surfaces of the bone defect. These blocks can also act as bulk supports to orthopedic prostheses or other types of graft tissue. These blocks can be shaped into any number of appropriate shapes and configurations in order to suit the particular clinical needs of the patient. 
     In order to preserve the useful shelf life of allograft tissue, as well as to inhibit bacterial growth within the allograft tissue, it is becoming common practice to dehydrate the allograft tissue, especially by freeze-drying. Freeze-drying quickly removes virtually all of the moisture within the allograft tissue, thus inhibiting any subsequent bacterial growth. However, prior to employing the allograft tissue in a surgical setting, it is generally necessary to re-hydrate the freeze-dried allograft tissue with some sort of fluid, such as sterilized water, saline, or the like. 
     Typically, the freeze-dried allograft tissue is removed from its protective packaging and either introduced into a liquid source or the liquid source is introduced onto the freeze-dried allograft tissue. This is a cumbersome and sometimes sloppy process that unnecessarily exposes the freeze-dried allograft tissue to atmospheric pathogens during the rehydration process. Additionally, this haphazard process does not ensure that the liquid material will thoroughly infuse into the pores of the allograft tissue. 
     Additionally, xenograft materials (e.g., non-human or animal-based graft materials) as well as synthetic materials (e.g., ceramic graft materials such as calcium-based materials, calcium-phosphate-based materials, calcium-sulfate-based materials, calcium-sodium-phosphate-based materials, as well as many others) have been used as orthopedic graft materials as well. However, these materials, must also be either rehydrated, in the case of dehydrated xenografts, or hydrated in the case of dry porous synthetic materials. Therefore, the same general problems described above are also encountered with these materials as well. 
     Therefore, there still exists a need for an apparatus and method for either hydrating dry porous orthopedic graft materials or rehydrating dehydrated orthopedic graft materials such that the respective orthopedic graft materials can be either hydrated and/or rehydrated in a sterile, efficient, and cost-effective manner. 
     SUMMARY OF THE INVENTION 
     In accordance with one embodiment of the present invention, a container for storing orthopedic graft materials is provided, comprising: (1) a dividing device for dividing the container into first and second compartments and for isolating the compartments from one another, the first compartment capable of receiving a liquid component and the second compartment containing an orthopedic graft material under vacuum; and (2) a vacuum reservoir device in communication with the second compartment, the vacuum reservoir device being capable of taking up substantially all residual interstitial gases and thereby ensuring thorough infusion of the liquid component into the orthopedic graft material component upon release of the dividing device so as to form a hydrated orthopedic graft material. 
     In accordance with a second embodiment of the present invention, a container for storing orthopedic materials is provided, comprising: (1) a dividing device for dividing the container into first and second compartments and for isolating the compartments from one another, the first compartment containing a liquid component and the second compartment containing an orthopedic graft material under vacuum; and (2) a vacuum reservoir device in communication with the second compartment, the vacuum reservoir device being capable of taking up substantially all residual interstitial gases and thereby ensuring thorough infusion of the liquid component into the orthopedic graft material component upon release of the dividing device so as to form a hydrated orthopedic graft material. 
     In accordance with a third embodiment of the present invention, a container for storing orthopedic graft materials is provided, comprising: (1) a dividing device for dividing the container into first and second compartments and for isolating the compartments from one another, the first compartment containing a liquid component and the second compartment containing an orthopedic graft material under vacuum; (2) an elongated pocket portion extending from and in communication with the second compartment; (3) a gas permeable membrane disposed between the second compartment and the pocket portion; and (4) a vacuum reservoir device disposed within the pocket portion and being in communication with the second compartment, the vacuum reservoir device being capable of taking up substantially all residual interstitial gases and thereby ensuring thorough infusion of the liquid component into the orthopedic graft material component upon release of the dividing device so as to form a rehydrated orthopedic graft material. 
     In accordance with a fourth embodiment of the present invention, a method for hydrating an orthopedic graft material is provided, comprising: (1) providing a container, including: (a) a dividing device for dividing the container into first and second compartments and for isolating the compartments from one another, the first compartment capable of receiving a liquid component and the second compartment containing an orthopedic graft material under vacuum; and (b) a vacuum reservoir device in communication with the second compartment, the vacuum reservoir device being capable of taking up substantially all residual interstitial gases and thereby ensuring thorough infusion of the liquid component into the orthopedic graft material component upon release of the dividing device so as to form a hydrated orthopedic graft material; and (2) releasing the dividing device, whereupon the liquid component rapidly migrates into the second compartment and thoroughly infuses into the orthopedic graft material component so as to form a hydrated orthopedic graft material. 
     In accordance with a fifth embodiment of the present invention, a method for hydrating an orthopedic graft material is provided, comprising: (1) providing a container, including: (a) a dividing device for dividing the container into first and second compartments and for isolating the compartments from one another, the first compartment containing a liquid component and the second compartment containing the orthopedic graft material under vacuum; and (b) a vacuum reservoir device in communication with the second compartment, the vacuum reservoir device being capable of taking up substantially all residual interstitial gases; and (2) releasing the dividing device, whereupon the liquid component rapidly migrates into the second compartment and thoroughly infuses into the orthopedic graft material component so as to form a hydrated orthopedic graft material. 
     In accordance with a sixth embodiment of the present invention, a method for hydrating an orthopedic graft material is provided, comprising: (1) providing a container, including: (a) a dividing device for dividing the container into first and second compartments and for isolating the compartments from one another, the first compartment containing a liquid component and the second compartment containing the orthopedic graft material under vacuum; (b) an elongated pocket portion extending from and in communication with the second compartment; (c) a gas permeable membrane disposed between the second compartment and the pocket portion; and (d) a vacuum reservoir device disposed within the pocket portion and being in communication with the second compartment, the vacuum reservoir device being capable of taking up substantially all residual interstitial gases; and (2) releasing the dividing device, whereupon the liquid component rapidly migrates into the second compartment and thoroughly infuses into the orthopedic graft material component so as to form a hydrated orthopedic graft material. 
    
    
     A more complete appreciation of the present invention and its scope can be obtained from the following detailed description of the invention, the drawings, and the appended claims. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
     FIG. 1 illustrates a perspective view of a packaging system for orthopedic graft materials, in accordance with one embodiment of the present invention; 
     FIG. 1 a  illustrates a perspective view of a packaging system for morselized orthopedic graft materials, in accordance with one embodiment of the present invention; 
     FIG. 1 b  illustrates a perspective view of a packaging system for machined shape synthetic orthopedic graft materials, in accordance with one embodiment of the present invention; 
     FIG. 2 illustrates a top plan view of a packaging system for orthopedic materials, in accordance with one embodiment of the present invention; 
     FIG. 3 illustrates a side elevational view of a packaging system for orthopedic materials, in accordance with one embodiment of the present invention; 
     FIG. 4 illustrates an exploded view of a clamp of the packaging system for orthopedic materials, in accordance with one embodiment of the present invention; 
     FIG. 5 illustrates a partial cross-sectional view of the clamp of the packaging system for orthopedic materials, in accordance with one embodiment of the present invention; 
     FIG. 6 illustrates a perspective view of a material introduction device on the packaging system for orthopedic materials, in accordance with one embodiment of the present invention; 
     FIG. 7 illustrates a top plan view of the initial infusion process of the dehydrated orthopedic graft material, in accordance with one embodiment of the present invention; 
     FIG. 8 illustrates a perspective view of the initial infusion process of the dehydrated orthopedic graft material, in accordance with one embodiment of the present invention; 
     FIG. 9 illustrates a top plan view of the completion of the infusion process of the dehydrated orthopedic graft material, in accordance with one embodiment of the present invention; 
     FIG. 10 illustrates a perspective view of the completion of the infusion process of the dehydrated orthopedic graft material, in accordance with one embodiment of the present invention; 
     FIG. 11 illustrates a perspective view of the opening of the packaging system for orthopedic materials, in accordance with one embodiment of the present invention; and 
     FIG. 12 illustrates a perspective view of the rehydrated orthopedic graft material being removed from the packaging system for orthopedic materials, in accordance with one embodiment of the present invention. 
    
    
     The same reference numerals refer to the same parts throughout the various Figures. 
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention is useful for the hydration and rehydration of any number of different orthopedic graft materials, such as but not limited to allograft materials (e.g., human-based graft materials), xenograft materials (e.g., non-human or animal-based graft materials), and synthetic materials (e.g., ceramic graft materials such as calcium-based materials, calcium-phosphate-based materials, calcium-sulfate-based materials, calciumsodium-phosphate-based materials, as well as many others). 
     These various orthopedic graft materials, especially the synthetic materials, can be shaped into any number of configurations, including but not limited to blocks, rings, struts, machined shapes, chips, morsels, granules, and so forth. 
     Furthermore, ceramic cements, such as but not limited to tetracalcium phosphate/tricalcium phosphate cement, calcium sodium phosphate cement, and calcium sulfate, may also be used as orthopedic graft materials. The powder portion would typically be mixed with a citric acid solution or a citrate salt solution in order to form a thick paste which hardens in 5 to 15 minutes. 
     By the term “orthopedic graft material,” as that term is used herein, it is meant any orthopedic material that is capable of either being hydrated and/or rehydrated. By the term “rehydrated,” as that term is used herein, it is meant either hydrated and/or rehydrated. 
     The hydrating and/or rehydrating material may be comprised of any number of aqueous-based liquids, such as water, saline, or the like. Additionally, biologically active materials (e.g., therapeutic and/or prophylactic), such as but not limited to antibiotics, platelet concentrates, bone growth factors, may be introduced into the hydrating and/or rehydrating material, or alternatively, may comprise a portion of, or the entire volume of, the hydrating and/or rehydrating material. 
     Referring now to FIGS. 1-3, a packaging system for orthopedic materials is shown designated generally by the reference numeral  10 . The packaging system  10  is somewhat similar to the packaging systems described in U.S. Pat. Nos. 5,370,221 and 5,398,483, the entire specifications of which are incorporated herein by reference. 
     The packaging system  10  of the present invention primarily includes a preferably flexible container  12 , a divider or clamp  14 , a tubular portion  16 , a vacuum reservoir  18 , and an optional gas permeable membrane  20 . Preferably, the optional gas permeable membrane  20  is also substantially liquid impermeable. By way of a non-limiting example, the material to be stored can be either substantially solid allograft materials (FIG.  1 ), morselized allograft materials (FIG. 1 a ), xenograft materials (not shown), synthetic materials (FIG. 1 b ), as well as other types of orthopedic graft materials. 
     The container  12  preferably includes a front panel  22  and a rear panel  24 , each made of a thin generally impervious flexible film or laminate. The exact nature of the thin generally impervious flexible film or laminate to be used with the container  12  of the present invention depends upon the nature of the materials to be stored and the conditions under which the materials will be combined and used. For many applications and materials, films and/or laminates of polyethylene, TEFLON, polyester, nylon, ethyl vinyl alcohol, metal foil, laminated glass and various combinations of the foregoing materials may be used. However, it will be appreciated that other suitable materials may also be used as well. 
     Additionally, while the container  12  is shown as being substantially rectangular, it is to be understood that the present invention is applicable to flexible containers of other shapes, such as square, triangular or trapezoidal and may have curved edges. 
     The panels  22  and  24  can be formed from a single sheet of flexible film sealed to each other at a bottom edge  26  and side edges  28  and  30 . 
     As noted, the container  12  further includes a tubular portion  16  which is sealed along its continuous edge  32  similar to the edges  26 ,  28 , and  30 . Disposed within the tubular portion  16  is the vacuum reservoir device  18 , the purpose of which will be more fully explained herein. 
     The clamp  14  is arranged to provide a temporary seal of the inner surfaces of the panels  20  and  22  to each other along a line extending from an initial point  34  on the sealed edge  28  to a terminal point  36  on the sealed edge  30  to form a first or upper compartment  38  and a second or lower compartment  40 . As will be appreciated by those skilled in the art, the clamp  14  is preferably placed on the container  12  prior to being filled with either the liquid component or the orthopedic graft material component. 
     Referring to FIGS. 4-5, the clamp  14  comprises a C-shaped outer retention member  42  and an I-shaped inner retention member  44  which partially fits within the hollow of the C-shaped outer retention member  42 . When the clamp  14  is assembled with respect to the container  12  as shown in FIG. 5, the outer retention member  42  is positioned on the outside of the rear panel  22  and the inner retention member  44  is positioned on the outside of the front panel  20  such that the panels  20  and  22  are pinched together along a pair of parallel lines extending from the initial point  34  to the terminal point  36 . The inner retention member  44  has a contoured upper end which fits within the inner hollow of outer retention member  42  and has a thickness substantially equal to the inner distance between the open ends of the C-shaped section of the outside retention member  42  so that a double thickness of panels  20  and  22  is tightly compressed along a pair of parallel lines to form an effective seal or divider. The outer retention member  42  is made of a resilient material so that the inner retention member  44  may be forced into position therein by placing it over the entire length of the opening of the outer retention member  42  and then pressing it into place. Inner retention member  44  has a contoured upper end which can open the open ends of the C-shaped section of the outside retention member  42  to accommodate the inner retention member  44 . 
     The nature of the clamp  14  may also vary. The clamp  14  described in connection with the present invention consisting of an I-shaped inner retention member  44  and a C-shaped outer retention member  42 , is preferred because of its simplicity and ease of handling. However, other types of clamps suitable for applying pressure to the container  12  may also be used. In addition, it is possible to replace the clamp  14  with an additional separation seal or divider (not shown). In this embodiment, the separation seal can be either a heat seal or an adhesive seal to separate the upper compartment  38  from the lower compartment  40 . The strength of this separation seal must be such that it can be broken by placing pressure on either of the compartments  38  and  40  without damaging the panels  20  and  22 . This separation seal may also be used in conjunction with the clamp  14 . 
     The method of packaging the components of the orthopedic graft materials within the packaging  12  will now be described. The side edges  26  and  28  of the front panel  20  and the rear panel  22  are typically secured together by heat sealing, although other means of sealing may be used as well, such as adhesives. The clamp  14  is then placed over the front panel  20  and the rear panel  22  so as to form a temporary seal between the front panel  20  and the rear panel  22  and partially form the upper compartment  38  and the lower compartment  40  under environmentally controlled conditions. In certain circumstances, it will be necessary to position the orthopedic graft material D within the lower compartment  40  prior to heat sealing of the respective edges of the lower compartment  40  due, in part, to the size and configuration of the orthopedic graft material. In that circumstance, once the orthopedic graft material D is properly positioned, a heat seal then closes the lower compartment  40 . The container  12  is then sterilized employing gamma radiation, electron beam or other means. The liquid component L (e.g., water, saline, or the like) is then filled into the upper compartment  38  under aseptic conditions and then the upper compartment  38  is closed by the seal  24 . However, it should be noted that it is not necessary that the liquid component L be added at the same time the orthopedic graft material D is introduced. For example, the liquid component L can be introduced immediately before the infusion process is to take place, for example, in the operating room. Additionally, a port device  46  may be provided on the upper compartment  38  in order to introduce additional materials into the liquid component L (via syringe  48 ), such as but not limited to biologically active materials, as shown in FIG.  6 . Preferably, the port device  46  is self-sealing, or is provided with a cap or similar device, so as to prevent any leakage problems. 
     The main benefit of the present invention is that it provides a system for in situ mixing of the two components to produce a rehydrated orthopedic graft material. This is achieved by maintaining the lower compartment  40  under vacuum. This vacuum condition is facilitated by the presence of the vacuum reservoir  18  in the tubular portion  16 . The vacuum reservoir  18  preferably has a sufficiently large volume to take up the residual gases which will be replaced in the interstitial voids between the particles of the orthopedic graft material by the liquid component upon release or breaking of the seal between the first and second compartments. The purpose of the optional gas permeable membrane  20  is to allow air to be drawn out of the lower compartment  40  (e.g., during the creation of the vacuum condition), while preventing any liquid or particulate matter from penetrating into the tubular portion  16 . 
     The force which transfers the liquid component L into the second compartment  40  to combine with the orthopedic graft material component D is thus the pressure differential between the atmospheric pressure acting on the walls of the first compartment  38  and the pressure prevailing in the second compartment  40 . The function of the vacuum reservoir  18  is to maintain a sufficiently low pressure in the second compartment  40  until the orthopedic graft material component D has been completely and thoroughly infused by the liquid component L. Once the clamp  14  has been removed, the liquid component L will rapidly flow into the second compartment  40 , completely and thoroughly infusing the orthopedic graft material component D, as shown in FIGS. 7-8. Once the infusion process is complete, the hydrated (or rehydrated) orthopedic graft material R will be ready for immediate implantation, as shown in FIGS. 9-10 Following the infusion process, the container  12  holding the hydrated/rehydrated orthopedic graft material R is opened (see FIG. 11) and the hydrated/rehydrated graft material R is removed (see FIG.  12 ), preferably with a sterile instrument such as a forceps  50 , and is now ready for immediate affixation onto a bone defect, for example. 
     The foregoing description is considered illustrative only of the principles of the invention. Furthermore, because numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and process shown as described above. Accordingly, all suitable modifications and equivalents that may be resorted to that fall within the scope of the invention as defined by the claims that follow.