Abstract:
An intramedullary device comprises a tubular body extending along a center longitudinal axis. The tubular body includes a first end and a second end. The first end is configured to engage a stem of an implant.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 61/975,154, filed on Apr. 4, 2014. The entire disclosure of the above application is incorporated herein by reference. 
     
    
     FIELD 
       [0002]    The present disclosure generally relates to an intramedullary device for treating periprosthetic fractures. 
       BACKGROUND 
       [0003]    This section provides background information related to the present disclosure and is not necessarily prior art. 
         [0004]    Fractures termed periprosthetic fractures may occur in patients proximate to joint replacement implants. Such fractures may occur intraoperatively or postoperatively. Periprosthetic fractures may be conventionally treated using nails, screws, plates, and cables. While known treatments have proven to be generally acceptable, a continued need for improvement in the relevant art remains. 
       SUMMARY 
       [0005]    This section provides a general summary of the disclosure, and is not intended to be a comprehensive disclosure of its full scope or all of its features. 
         [0006]    According to one particular aspect, the present disclosure provides an intramedullary device including a tubular body extending along a center longitudinal axis. The tubular body includes a first end and a second end. The first end is configured to engage a stem of an implant. 
         [0007]    According to another particular aspect, the present disclosure provides an implantable construct including a knee implant, a hip implant having an intramedullary hip stem and an intramedullary tube. The intramedullary tube extends along a longitudinal axis from a proximal end to a distal end. The proximal end of the intramedullary tube includes a cavity configured to receive and engage a distal end of the intramedullary hip stem therein. The distal end of the intramedullary tube is configured to engage the knee implant. 
         [0008]    According to yet another particular aspect, the present disclosure provides a method for fixating a bone. The method includes providing a tubular member; inserting the tubular member into an intramedullary canal of a patient; and engaging a first end of the tubular member with a stem of an implant while the stem is in the intramedullary canal of the patient. 
         [0009]    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 
         [0010]    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. 
           [0011]      FIG. 1  is a perspective view of an exemplary construct including an intramedullary device in accordance with the teachings of the present disclosure, the exemplary construct is further shown to include a hip stem and a knee femoral component; 
           [0012]      FIG. 2  is an exploded perspective view of the construct of  FIG. 1 ; 
           [0013]      FIG. 3  is a cross-sectional view of the intramedullary device of the present teachings taken along the line  3 - 3  of  FIG. 2 ; 
           [0014]      FIG. 4  is an exploded, partial cross-sectional view of another exemplary construct including an intramedullary device in accordance with the teachings of the present disclosure, the exemplary construct is further shown to include a hip stem; 
           [0015]      FIG. 5  is a partial cross-sectional view of the exemplary construct of  FIG. 4 , the exemplary construct is further shown operatively associated with a cement gun; 
           [0016]      FIG. 6A  is an exploded, partial cross-sectional view of another exemplary construct including an intramedullary device in accordance with the teachings of the present disclosure, the exemplary construct is further shown to include a distal tip of a hip stem; 
           [0017]      FIG. 6B  is a partial cross-sectional view of the exemplary construct of  FIG. 6A , the exemplary construct is shown to include the distal tip of the hip stem received in the intramedullary device in accordance with the teachings of the present disclosure; 
           [0018]      FIG. 6C  is another partial cross-sectional view of the exemplary construct of  FIG. 6A , the exemplary construct is shown to include the distal tip of the hip stem received in the intramedullary device in accordance with the teachings of the present disclosure; 
           [0019]      FIG. 6D  is a cross-sectional view of the construct of  FIG. 6C  taken along the line  6 D- 6 D of  FIG. 6C ; 
           [0020]      FIG. 7A  is an exploded, partial cross-sectional view of another exemplary construct including an intramedullary device in accordance with the teachings of the present disclosure, the exemplary construct is further shown to include a distal tip of a hip stem; 
           [0021]      FIG. 7B  is a partial cross-sectional view of the exemplary construct of  FIG. 7A , the exemplary construct is shown to include the distal tip of the hip stem received in the intramedullary device in accordance with the teachings of the present disclosure; and 
           [0022]      FIG. 7C  is another partial cross-sectional view of the exemplary construct of  FIG. 7A , the exemplary construct is shown to include the distal tip of the hip stem received in the intramedullary device in accordance with the teachings of the present disclosure. 
       
    
    
       [0023]    Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
       DETAILED DESCRIPTION 
       [0024]    The following description is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. For example, although the present description describes treatment of a periprosthetic fracture in a patient&#39;s femur, the present teachings can also be used to treat fractures in other bones. It will be understood that general surgical procedures are outlined only as needed to illustrate the devices and methods provided by the present teachings, while detailed descriptions of standard and known procedures and instruments are omitted for simplicity. Example embodiments will now be described more fully with reference to the accompanying drawings. 
         [0025]    With initial reference to  FIGS. 1-3 , an intramedullary device for treating periprosthetic fractures constructed in accordance with the teachings of the present disclosure is illustrated and generally identified at reference numeral  10 . In  FIGS. 1 and 2 , the intramedullary device  10  is shown incorporated into an exemplary construct  12 . In this particular exemplary construct  12 , the intramedullary device  10  is shown operatively associated with a hip stem  14  and a knee femoral component  16 . Insofar as the present teachings are concerned, it will be understood that the hip stem  14  and the knee femoral component  16  are conventional in construction to any extent not otherwise described herein. It will be further understood that the present teachings may be used in connection with other implants and that the present teachings have application beyond the exemplary construct  12  illustrated in the drawings and described herein. 
         [0026]    The intramedullary device  10  is an elongated member extending between a proximal end  18  and a distal end  20 . According to one exemplary and non-limiting use, the intramedullary device  10  and the other intramedullary devices described below may be configured for insertion into the intramedullary canal of a patent&#39;s femur (not illustrated). According to other exemplary and non-limiting uses, the intramedullary device  10  and the other intramedullary devices described below may be configured for insertion into the intramedullary canal of other bones, including, but not limited to, the tibia and the humerus, for example. 
         [0027]    With specific reference to  FIGS. 1 and 2 , the proximal end  18  of the intramedullary device  10  may be configured to engage the hip stem  14 . The distal end  20  of the intramedullary device  10  may be configured to pass through an opening  22  in the knee femoral component  16 . In this manner, the intramedullary device  10  may be implanted while the knee femoral component  16  is attached to the distal end of the femur. The proximal end  18  of the intramedullary device  10  may be correspondingly configured to engage other orthopedic implants, such as a tibial tray component or a shoulder stem. In these other applications, the distal end  20  of the intramedullary device  10  may be configured to pass through or attach to other orthopedic implants. 
         [0028]    With continued reference to  FIGS. 1-3 , the intramedullary device  10  of the present disclosure may be fabricated from any material suitable for implantation and having requisite strength requirements including, but not limited to metal, ceramic, polymeric materials, and combinations thereof. A center bore  24  may extend longitudinally through the intramedullary device  10  between the proximal and distal ends  18 ,  20 , thereby defining an inner channel or cavity  26  and an outer surface  28 . The cavity  26  may include a cross section having a circular shape, or the cross section may include a different shape, such as an ovoid shape for example. Similarly, the outer surface  28  may include a cross section having a circular shape, or the cross section may include a different shape. Further, between the ends  18 ,  20 , the intramedullary device  10  may include bends and/or other geometry that generally corresponds to the anatomical shape of the intramedullary canal. Accordingly, the overall geometry of the intramedullary device  10 , including the cross section, length, and width may vary depending on its intended use. 
         [0029]    At least one through bore (not illustrated) may extend through the intramedullary device  10  in a generally perpendicular or generally angular direction with respect to the longitudinally extending center bore  24 . Once the intramedullary device  10  is inserted into the intramedullary canal of a patient&#39;s femur, the through bore(s) may provide for a bone fixation device(s), such as a plate, rod, screw, nail, etc., for example, to pass through the intramedullary device  10  and provide additional femoral fixation. 
         [0030]    At the proximal end  18 , the intramedullary device  10  may include a plurality of slots  30  cooperating to form a plurality of integral fingers  32 . As perhaps best shown in the exploded view of  FIG. 2 , the intramedullary device  10  may include four slots  30  cooperating to form four fingers  32 . It will be understood, however, that the intramedullary device  10  may include any number of slots  30  and fingers  32  within the scope of the present teachings. Alternatively, the fingers  32  may be rigidly attached to the proximal end  18  of the intramedullary device  10 . 
         [0031]    As will be described further below, as the intramedullary device  10  is inserted into the intramedullary canal of a patient&#39;s femur, the fingers  32  may radially deflect in a radial direction to engage and capture a distal end  34  of the hip stem  14  within the cavity  26 . Each finger  32  may include a tapered end  36 , which may assist in inserting the intramedullary device  10  into the intramedullary canal and/or assist in engaging and capturing the distal end  34  of the hip stem  14  within the cavity  26 . The intramedullary device  10  may also include features within the cavity  26 , such as a push rod or a balloon, for example (not illustrated), to assist in radially deflecting the fingers  32  open to capture the distal end  34  of the hip stem  14  within the cavity  26 . 
         [0032]    At the distal end  20 , the intramedullary device  10  may include a threaded portion  38 . A fastening means (not illustrated) may engage the threaded portion  38  and/or the intramedullary device  10  to attach the intramedullary device  10  to the knee femoral component  16 . An insertion instrument (not illustrated) may be configured to engage the threaded portion  38  and/or the distal end  20  of the intramedullary device  10  to facilitate insertion of the intramedullary device  10  into the intramedullary canal of a patient&#39;s femur. The insertion instrument may also be configured to actuate the features within the cavity  26  (i.e., the push rod or the balloon describe above, for example) to radially deflect the fingers  32  open to capture the distal end  34  of the hip stem  14  within the cavity  26 . 
         [0033]    With continued reference to  FIGS. 1-3 , a method for treating a periprosthetic fracture in the femur of a patient having an existing hip stem  14  and knee femoral component  16  will be described. Using the insertion instrument for example, the proximal end  18  of the intramedullary device  10  may be inserted in a retrograde direction through the opening  22  in the knee femoral component  16  and into the intramedullary canal of the patient&#39;s femur. As the intramedullary device  10  is inserted into the intramedullary canal and the fingers  32  make contact with the distal end  20  of the hip stem  14 , pressure applied by the hip stem  14  against the fingers  32  may cause the fingers  32  to outwardly deflect in a radial direction. Accordingly, as the intramedullary device  10  is further inserted into the intramedullary canal, the fingers  32  may engage and capture the distal end  34  of the hip stem  14  within the cavity  26 . Alternatively, as the fingers  32  make contact with the distal end  34  of the hip stem  14 , the features within the cavity  26  (i.e., the push rod and/or the balloon) may cause the fingers  32  to radially deflect open and capture the distal end  34  of the hip stem  14  within the cavity  26 . 
         [0034]    In an alternative embodiment (not illustrated), the intramedullary device  10  may extend from a closed box of an otherwise conventional knee femoral component. The intramedullary device  10  may be formed with the knee femoral component or suitably attached to the knee femoral component. For example, the fastening means may engage the threaded portion  38  and/or the intramedullary device  10  to attach the intramedullary device  10  to the knee femoral component. Once attached, the proximal end  18  of the intramedullary device  10  may be inserted into the intramedullary canal of the femur. As the intramedullary device  10  is inserted into the intramedullary canal and the fingers  32  make contact with the distal end  34  of the hip stem  14 , pressure applied by the hip stem  14  against the fingers  32  may again cause the fingers  32  to outwardly deflect in a radial direction and capture the distal end  34  of the hip stem  14  within the cavity  26 . Alternatively, as the fingers  32  make contact with the distal end  34  of the hip stem  14 , the features within the cavity  26  (i.e., the push rod and/or the balloon) may cause the fingers  32  to radially deflect open and capture the distal end  34  of the hip stem  14  within the cavity  26 . 
         [0035]    With reference to  FIGS. 4 and 5 , another intramedullary device for treating periprosthetic fractures constructed in accordance with the teachings of the present disclosure is illustrated and generally identified at reference numeral  110 , which can be incorporated into an exemplary construct  112 . In this particular exemplary construct  112 , the intramedullary device  110  is shown associated with a conventional hip stem  114 ; however, it will be understood that the intramedullary device  110  may be used in connection with other implants and that the present teachings have application beyond the exemplary construct  112  illustrated in the drawings and described herein. 
         [0036]    Similar to the intramedullary device  10  described above, the intramedullary device  110  is an elongated member fabricated from a material having requisite strength properties and suitable for implantation into the intramedullary canal of a patient&#39;s bone, including, but not limited to the femur, tibia and the humerus (none illustrated), for example. A proximal end  116  of the intramedullary device  110  can be configured to engage a distal end  120  of the hip stem  114 . A distal end  118  of the intramedullary device  110  can be configured to pass through and/or engage an orthopedic implant, such as a knee femoral component, tibial tray component or a shoulder stem (none illustrated), for example. 
         [0037]    A center bore  122  may extend longitudinally through the intramedullary device  110 , between the proximal and distal ends  116 ,  118 , thereby defining a cavity  124 . At least one through bore (not illustrated) may extend through the intramedullary device  110  in a direction generally transverse to the center bore  122 . The through bore(s) can provide for a fixation device(s), such as a plate, rod, screw, nail, etc., for example, to pass through the intramedullary device  110  and provide additional femoral fixation. 
         [0038]    Within the cavity  124 , the intramedullary device  110  may include a first barrier  126  and a second barrier  128  cooperating to form a chamber  130  therebetween. The barriers  126 ,  128  may be fabricated from a material similar to the material of the intramedullary device  110 , or may be fabricated from a material having flexible sealing properties, such as a plastic or elastomeric material, for example. The first barrier  126  may include a first opening  132 , and the second barrier  128  may include a second opening  134 . 
         [0039]    Referring specifically to  FIG. 5 , the distal end  120  of the hip stem  114  can be received in the chamber  130  of the intramedullary device  110  through the first opening  132  in the first barrier  126 . An ancillary tool  136 , such as an injection instrument or cement gun, for example, or, more specifically, a delivery nozzle or tip of the ancillary tool  136 , can be inserted into the distal end  118  of the intramedullary device  110  and through the second opening  134  in the second barrier  128 . As will be described in further detail below, with the distal end  120  of the hip stem  114  received in the chamber  130 , the ancillary tool  136  can be configured to deliver or inject a cement or bonding mixture  138  into the chamber  130  to engage and secure the distal end  120  of the hip stem  114  within the chamber  130 . 
         [0040]    With continued reference to  FIG. 5 , a method for treating a periprosthetic fracture in the femur of a patient having an existing hip stem  114  will now be described. Using known techniques, the proximal end  116  of the intramedullary device  110  can be inserted in a retrograde direction into the intramedullary canal of the patient&#39;s femur until a portion of the distal end  120  of the hip stem  114  is received through the first opening  132  in the first barrier  126  and in the chamber  130 . The ancillary tool  136  can be inserted into the distal end  120  of the intramedullary device  110  and through the second opening  134  in the second barrier  128 . With the chamber  130  at least partially sealed at the upper and lower ends by the distal end  120  of the hip stem  114  and the ancillary tool  136  respectively, the bonding mixture  138  can be delivered or injected into the chamber  130  and surround the distal end  120  of the hip stem  114 . As the bonding mixture  138  is curing, or once the bonding mixture  138  has cured, the ancillary tool  136  can be removed from the distal end  120  of the intramedullary device  110 . Accordingly, the distal end  120  of the hip stem  114  is engaged and secured within the intramedullary device  110 . 
         [0041]    With reference to  FIGS. 6A-6D , a proximal end  212  of another intramedullary device  210  for treating periprosthetic fractures constructed in accordance with the teachings of the present disclosure is illustrated. The intramedullary device  210  is shown associated with a distal end  216  of conventional hip stem  214 ; however, it will again be understood that the present teachings may be used in connection with other implants 
         [0042]    Similar to the intramedullary devices  10 ,  110  described above, intramedullary device  210  is an elongated member fabricated from a material having requisite strength properties and suitable for implantation into the intramedullary canal of a patient&#39;s bone, including, but not limited to the femur, tibia and the humerus (none illustrated), for example. The proximal end  212  of the intramedullary device  210  can be configured to engage the distal end  216  of the hip stem  214 . The distal end (not illustrated) of the intramedullary device  210  can be configured to pass through and/or engage an orthopedic implant, such as a knee femoral component, a tibial tray component or a shoulder stem (none illustrated). 
         [0043]    A center bore  218  may extend longitudinally through the intramedullary device  210 , thereby defining a cavity  220  within the intramedullary device  210 . Within the cavity  220 , a barrier or wall  224  may extend transversely to the center bore  218 , thereby defining an open-ended chamber  226  at the proximal end  212  of the intramedullary device  210 . With specific reference to  FIG. 6A , a plurality of fingers or rods  228  in a first configuration may extend upwardly from the wall  224  toward the proximal end  212  of the intramedullary device  210 . As shown in this first configuration, the rods  228  may extend generally straight and parallel to one another. The rods  228  may be fabricated from a shape-memory alloy, which may be referred to in the art as “memory metal.” A characteristic of a shape-memory alloy is that, generally, it “remembers” its original shape once it has been deformed and then heated. Stated another way, when a shape-memory alloy is deformed, and subsequently heated past a predetermined transfer temperature, the deformed shape-memory alloy returns to its original pre-deformed shape. 
         [0044]    Referring specifically to  FIG. 6B , the distal end  216  of the hip stem  214  can be configured to be received in the proximal end  212  of the intramedullary device  210  and positioned within the chamber  226  amongst the rods  228 . To make room for the distal end  216  of the hip stem  214  within the chamber  226 , the rods  228  may deform, bend, move, and/or flex from the first configuration shown in  FIG. 6A  to a second configuration shown in  FIG. 6B . It is understood that when the rods  228  are in the second configuration shown in  FIG. 6B , the distal end  216  of the hip stem  214  may still be moveable within the chamber  226  amongst the rods  228 . However, as will be described further below, when the rods  228  are heated and try to return to their original de-formed configuration (i.e., generally straight and parallel to one another), the rods  228  may apply a pressure or force onto the distal end  216  of the hip stem  214 , thereby engaging and securing the hip stem  214  within the chamber  226 . 
         [0045]    With continued reference to  FIG. 6A-6D , a method for treating a periprosthetic fracture in the femur of a patient having an existing hip stem  214  will now be described. Using known techniques, the proximal end  212  of the intramedullary device  210  can be inserted in a retrograde direction into the intramedullary canal of the patient&#39;s femur until a portion of the distal end  216  of the hip stem  214  is received in the chamber  226  ( FIG. 6B ). Accordingly, as the distal end  216  of the hip stem  214  is received in the chamber  226 , the rods  228  may deform, bend, move, and/or flex. Once the distal end  216  of the hip stem  214  is in an appropriate position within the chamber  226 , sufficient heat from a conventional heat source (not illustrated) that is above the transfer temperature of the rods  228  can be applied to the intramedullary device  210  to try to return the rods  228  to their original pre-deformed shape. Alternatively, the transfer temperature of the rods  228  may be close to body temperature. Accordingly, with the intramedullary device  210  in the intramedullary canal of the patient&#39;s femur, body heat from the patient may function to try to return the rods  228  to their original pre-deformed shape. As the rods  228  try to return to their original de-formed configuration (i.e., generally straight and parallel to one another), the rods  228  may apply a pressure or force onto the hip stem  214 , thereby engaging and capturing the hip stem  214  therein. 
         [0046]    With reference to  FIGS. 7A-7C , a proximal end  312  of another intramedullary device  310  for treating periprosthetic fractures constructed in accordance with the teachings of the present disclosure is illustrated. The intramedullary device  310  is shown associated with a distal end  316  of a conventional hip stem  314 ; however, it will again be understood that the present teachings may be used in connection with other implants. 
         [0047]    Similar to the intramedullary devices  10 ,  110 ,  210  described above, intramedullary device  310  is an elongated member fabricated from a material having requisite strength properties and suitable for implantation into the intramedullary canal of a patient&#39;s bone, including, but not limited to the femur, tibia and the humerus (none illustrated), for example. The proximal end  312  of the intramedullary device  310  can be configured to engage the distal end  316  of the hip stem  314 . The distal end (not illustrated) of the intramedullary device  310  can be configured to pass through and/or engage an orthopedic implant, such as a knee femoral component, a tibial tray component or a shoulder stem (none illustrated). 
         [0048]    A center bore  318  may extend longitudinally through the intramedullary device  310 , thereby defining a cavity  320  having an inner surface  322  within the intramedullary device  310 . Within the cavity  320 , a barrier or wall  324  may extend transversely to the center bore  318 , thereby defining an open-ended chamber  326  at the proximal end  312  of the intramedullary device  310 . With specific reference to  FIG. 7A , a plurality of fingers or rods  328  in a first configuration may extend horizontally from the inner surface  322  of the chamber  326 . In this first configuration, the rods  328  may extend generally straight and parallel to one another and generally perpendicular to the center bore  318 . Similar to the rods  228  described above, the rods  328  may be fabricated from a shape-memory alloy, which may also be known in the art as “memory metal.” As described above, when a shape-memory alloy is deformed, and then heated past a predetermined transfer temperature, the deformed shape-memory alloy tries to its original pre-deformed shape. 
         [0049]    Referring specifically to  FIG. 7B , the distal end  316  of the hip stem  314  can be configured to be received in the proximal end  312  of the intramedullary device  310  and positioned within the chamber  326  amongst the rods  328 . To make room for the distal end  316  of the hip stem  314  within the chamber  326 , the rods  328  may deform, bend, move, and/or flex from the first configuration shown in  FIG. 7A  to a second configuration shown in  FIG. 7B . It is understood that when the rods  328  are in the second configuration, the distal end  316  of the hip stem  314  may be moveable within the chamber  326  amongst the rods  328 . However, as will be described further below, when the rods  328  are heated and try to return to their original deformed configuration (i.e., generally straight and parallel to one another), the rods  328  may apply a pressure or force onto the with the distal end  316  of the hip stem  314  in the chamber  326 , thereby engaging the hip stem  314  therein. 
         [0050]    With continued reference to  FIG. 7A-7C , a method for treating a periprosthetic fracture in the femur of a patient having an existing hip stem  314  will now be described. Using known techniques, the proximal end  312  of the intramedullary device  310  can be inserted in a retrograde direction into the intramedullary canal of the patient&#39;s femur until a portion of the distal end  316  of the hip stem  314  is received in the chamber  326  ( FIG. 7B ). Accordingly, as the distal end  316  of the hip stem  314  is received into the chamber  326 , the rods  328  may deform, bend, move, and/or flex. Once the distal end  316  of the hip stem  214  is in an appropriate position within the chamber  326 , sufficient heat form a heat source (not illustrated) that is above the transfer temperature of the rods  328  can be applied to the intramedullary device  310  to try to return the rods  328  to their original pre-deformed shape. Alternatively, the transfer temperature of the rods  328  may be close to the body temperature of the patient. With the intramedullary device  310  in the intramedullary canal of the patient&#39;s femur, the patient&#39;s body heat may function to try to return the rods  328  to their original pre-deformed shape. Accordingly, as the rods  328  try to return to their original de-formed configuration (i.e., generally straight and parallel to one another), the rods  328  may apply a pressure or force onto the distal end  316  of the hip stem  314 , thereby engaging the hip stem  314  therein. 
         [0051]    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.