Patent Publication Number: US-2020289175-A1

Title: Modular femoral nail and method of use thereof

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 15/679,773, filed on Aug. 17, 2017, which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     In orthopedic surgeries, a nail is a fixation device designed to stabilize a fractured bone. For example, a nail may be introduced to the medullary canal of a fractured femur to stabilize the femur. Nails may be used to stabilize a variety of fractures (e.g., simple two-part fractures as well as multiple-part fractures) in a wide range of people. As such, nails are manufactured with various lengths, diameters, radii of curvature, fixation points, and so on. 
     SUMMARY OF THE INVENTION 
     One embodiment relates to an intramedullary nail for implantation within a fractured bone. The nail includes two or more nail modules. Each nail module has an elongated body with a first end and a second end. For each nail module, at least one of the first end or the second end is a connecting end configured to connect to a second connecting end on a second nail module. 
     Another embodiment relates to a modular intramedullary nail supply kit. The modular intramedullary nail supply kit includes a plurality of nail modules. Each nail module has an elongated body with a first end and a second end. For each nail module, at least one of the first end or the second end is a connecting end configured to connect to a second connecting end on a second nail module. A plurality of intramedullary nails can be formed by selecting and connecting at least two of the plurality of nail modules together. 
     Another embodiment relates to a method for building a customizable intramedullary nail. The method includes determining desired properties for the intramedullary nail and, based on the desired properties for the intramedullary nail, selecting two or more nail modules from a set of a plurality of nail modules. Each nail module has an elongated body with a first end and a second end. For each nail module, at least one of the first end or the second end is a connecting end. The method further includes connecting the two or more selected nail modules together to form the intramedullary nail by connecting at least one connecting end on each nail module with a second connecting end on a second nail module. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross-sectional view of a fractured femur with an intramedullary nail, according to an example embodiment. 
         FIG. 2A  is a side perspective view of separated male and female nail modules and a key, according to an example embodiment. 
         FIGS. 2B and 2C  are side views of the male nail module of  FIG. 2A , according to an example embodiment. 
         FIGS. 2D and 2E  are side views of the female nail module of  FIG. 2A , according to an example embodiment. 
         FIGS. 2F and 2G  are side views with partial cross-sections of the female nail module of  FIG. 2A , according to an example embodiment. 
         FIG. 2H  is a side perspective view of the key of  FIG. 2A , according to an example embodiment. 
         FIG. 2I  is a side view of the key of  FIG. 2A , according to an example embodiment. 
         FIG. 2J  is a top view of the key of  FIG. 2A , according to an example embodiment. 
         FIG. 2K  is a side perspective view of the male and female nail modules and key of  FIG. 2A  connected together, according to an example embodiment. 
         FIG. 2L  is a side view with a partial cross-section of the male and female nail modules and key of  FIG. 2A  connected together, according to an example embodiment. 
         FIG. 3  is a flow diagram illustrating a method of connecting male and female nail modules, according to an example embodiment. 
         FIGS. 4A and 4B  are side views of a male nail module, according to an example embodiment. 
         FIG. 4C  is a top view of the male nail module of  FIGS. 4A and 4B , according to an example embodiment. 
         FIG. 4D  is a side view of a female nail module, according to an example embodiment. 
         FIG. 4E  is a side view with a partial cross-section of the female nail module of  FIG. 4D , according to an example embodiment. 
         FIG. 4F  is a bottom perspective view of the female nail module of  FIG. 4D , according to an example embodiment. 
         FIG. 4G  is a side view of the male nail module of  FIGS. 4A and 4B  and the female nail module of  FIG. 4D  connected together, according to an example embodiment. 
         FIG. 4H  is a side view with a partial cross-section of the male nail module of  FIGS. 4A and 4B  and the female nail module of  FIG. 4D  connected together, according to an example embodiment. 
         FIGS. 5A and 5B  are side views of a male nail module, according to an example embodiment. 
         FIG. 5C  is a top view of the male nail module of  FIGS. 5A and 5B , according to an example embodiment. 
         FIGS. 5D and 5E  are side views of a female nail module, according to an example embodiment. 
         FIG. 5F  is a side view with a partial cross-section of the female nail module of  FIGS. 5D and 5E , according to an example embodiment. 
         FIG. 5G  is a bottom view of the female nail module of  FIGS. 5D and 5E , according to an example embodiment. 
         FIG. 5H  is a side view of the male nail module of  FIGS. 5A and 5B  and the female nail module of  FIGS. 5D and 5E  connected together, according to an example embodiment. 
         FIGS. 5I and 5J  are side views with partial cross-sections of the male nail module of  FIGS. 5A and 5B  and the female nail module of  FIGS. 5D and 5E  connected together, according to an example embodiment. 
         FIGS. 6A and 6B  are side views of female nail module with different fixation holes, according to example embodiments. 
         FIGS. 6C and 6D  are side views of a male nail module with different fixation holes, according to example embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     When a patient suffers a fractured long bone (e.g., a bone that is longer than it is wide, such as the femur, tibia, or humerus), the fracture may be treated by inserting an intramedullary rod into the medullary cavity of the bone, the central cavity of the bone where bone marrow is stored. For example,  FIG. 1  shows a femur  100  that has been fractured. The top (e.g., superior end) of the femur  100  includes a head  102  connected to a neck  104 , a greater trochanter  106 , and a lesser trochanter  108 . The bottom (e.g., inferior end) of the femur  100  includes a pair of condyles  110 . Extending between the top and the bottom of the femur  100  is a body  112  of the femur  100  containing a medullary cavity  114 . As further shown in  FIG. 1 , the femur  100  has suffered a fracture  116 . Accordingly, an intramedullary nail  118  has been inserted into the medullary cavity  114  of the femur  100  and secured in the femur  100  with screws  120 . The intramedullary nail  118  aligns and stabilizes the femur  100 , thereby facilitating the healing of the fracture  116 . The intramedullary nail  118  may be left in the femur  100  permanently, or the intramedullary nail  118  may be removed after the fracture  116  is healed. 
     However, one of the difficulties of using an intramedullary nail, such as intramedullary nail  118 , to stabilize a fracture is that the intramedullary nail needs to be matched to the specific anatomy of the fractured bone. For example, the same bone in different patients may have different lengths, different diameters, different bows (e.g., different levels of curvature), different bone qualities, and so on based on the patient&#39;s age, gender, and race. Additionally, the intramedullary nail should be matched to the type of fracture the patient has suffered (e.g., a simple two-part fracture versus a fracture that has broken the bone into several pieces) and which bone has suffered the fracture (e.g., a right femur versus a left femur, a tibia versus a femur). Accordingly, a surgeon who is implanting an intramedullary nail in a patient may need a variety of nails, with different angles, lengths, widths, bows, and fixation points, to select from. 
     Because of this, intramedullary nail manufacturers must manufacture a wide variety of intramedullary nails to meet patient needs. Further, a surgical facility must maintain an adequate supply of intramedullary nail options so that a surgeon can successfully implant an intramedullary nail into a patient to correct a fracture, particularly because unforeseen patient emergencies, unforeseen events, or inadequate surgical planning may arise. This may place significant demands on the surgical facility&#39;s acquisition and distribution department, as well as the facility&#39;s cleaning and sterilization infrastructures. Keeping an adequate stock of intramedullary nails may also be expensive, particularly with shipping costs for the variety of nails needed. Moreover, in the operating room, multiple unneeded surgical trays containing intramedullary nails may be opened to give the surgeon more treatment options, creating waste or sterilization issues. Even then, the surgeon must select from the available intramedullary nail options and has no ability to customize an intramedullary nail to fit a patient because the intramedullary nail features are static. 
     Accordingly, to address the manufacturing, inventory, shipping, and surgical services issues arising from the need for a variety of intramedullary nails to fit different patients, a modular intramedullary nail is provided herein. A modular intramedullary nail consists of two or more nail modules that interlock together to form an intramedullary nail. Accordingly,  FIG. 2A  illustrates a side perspective view of a male nail module  200  and a female nail module  202 , according to an exemplary embodiment, that may be connected together to form a modular intramedullary nail. Additionally, as further shown in  FIG. 2A , a modular intramedullary nail according to certain embodiments may include a key  204  configured to fit between the male nail module  200  and the female nail module  202 . 
       FIGS. 2B-2J  show the male nail module  200 , female nail module  202 , and key  204  in further detail. To begin with,  FIGS. 2B and 2C  illustrate side views of the male nail module  200 . As shown, the male nail module  200  includes a male connecting end  206 , which includes an elongated section  208  set off from the rest of the male nail module  200 . As shown in  FIGS. 2A-2C , at least part of the elongated section  208  is hollowed out and includes two slots  210  formed into the remaining circumference of the elongated section  208  and spaced directly across from each other on the elongated section  208 . The slots  210  create two prongs  212  in the remaining circumference of the elongated section  208 , each of the prongs  212  narrowing and ending in a lip  214 . Those of skill in the art will appreciate, however, that the elongated section of a male nail module may include more or fewer slots (e.g., such as shown on the male nail module  400  illustrated in  FIGS. 4A-4C  and described in further detail below), and the slots may be placed differently around the circumference of the elongated section to form different numbers and/or shapes of prongs in between the slots. Additionally, as shown in  FIGS. 2A-2C , in embodiments of a modular intramedullary nail including the key  204 , the bottom of the male connecting end  206  includes one or more notches  215 . 
       FIGS. 2D and 2E  illustrate side views of the female nail module  202 . Similar to the male nail module  200 , the female nail module  202  has a female connecting end  216 . However, the female connecting end  216  instead includes a receiving section  218 . As shown in  FIGS. 2F and 2G , which illustrate side views of the female nail module  202  with partial cross-sections of the female connecting end  216 , the receiving section  218  is hollowed out such that the receiving section  218  is configured to receive the elongated section  208  of the male nail module  200 . Accordingly, the receiving section  218  further includes a groove  220  configured to receive the lips  214  of the prongs  212 . Additionally, similar to the male nail module  200 , in embodiments of the modular intramedullary nail including the key  204 , the distal end of the female connecting end  216  includes one or more notches  222 . As shown in  FIGS. 2E and 2G , in some embodiments, the female nail module  202  may have a bow (e.g., the female nail module  202  may have a 3° to 5° curvature between the ends of the female nail module  202 ), though in other embodiments, the male nail module  200  may alternatively or additionally have a bow (e.g., the male nail module  200  may have a 3° to 5° curvature between the ends of the male nail module  200 ). 
       FIG. 2H  illustrates a side perspective view of the key  204 ,  FIG. 2I  illustrates a side view of the key  204 , and  FIG. 2J  illustrates a top view of the key  204 . As shown in  FIGS. 2H-2J , the key  204  is formed by a ring  224  with a pair of ridges  226  projecting from the top of the ring  224  and a pair of ridges  228  projecting from the bottom of the ring  224 . The top ridges  226  face each other across the ring  224 , as do the bottom ridges  228 . Further, as shown in  FIGS. 2H and 2I , the top ridges  226  are offset from the bottom ridges  228  such that the top ridges  226  and the bottom ridges  228  do not align with each other. However, it should be appreciated that  FIGS. 2H-2J  show an example of a key for a modular intramedullary nail. In other embodiments, a key may include additional or fewer ridges, and the ridges may be spaced differently around the ring forming the key. Further, in other embodiments, a key may include different offsets between the top ridges and bottom ridges of the key. 
       FIG. 2K  shows a side perspective view of the male nail module  200 , the female nail module  202 , and the key  204  connected together to form a modular intramedullary nail  230 .  FIG. 2L  shows a side view with a partial cross-section of the modular intramedullary nail  230  formed from the connected male nail module  200 , female nail module  202 , and key  204 . As shown in  FIGS. 2K and 2L , the elongated section  208  of the male connecting end  206  is configured to slide into the receiving section  218  of the female connecting end  216 . The lips  214  of the prongs  212  fit inside the groove  220 , thereby preventing the male connecting end  206  from slipping out of the female connecting end  216 . 
     In embodiments including the key  204 , the key  204  is configured to sit between the male connecting end  206  and the female connecting end  216 , with the top ridges  226  configured to fit in the notches  222  and the bottom ridges  228  configured to fit in the notches  215 . The key  204  thus prevents the male nail module  200  and the female nail module  202  from rotating relative to each other, as the notches  215  and  222  cannot slip past the ridges  226  and  228 , respectively. Additionally, the key  204  is able to alter the anteversion of the modular intramedullary nail  230  (e.g., the alignment of the male nail module  200  relative to the female nail module  202 ). As an example, a practitioner can use a key  204  with a greater offset between the top ridges  226  and bottom ridges  228  to rotate the female nail module  202  relative to the male nail module  200  in the resulting modular intramedullary nail  230 . Alternatively, a practitioner can use a key  204  with a lesser offset between the top ridges  226  and the bottom ridges  228  to provide less anteversion. Further, in certain embodiments, the key  204  may be able to alter the bow of the modular intramedullary nail  230 . For example, if the ring  224  of the key  204  is wider at one end and narrower at the other end, the key  204  may be able to alter the angle of the female nail module  202  relative to the male nail module  200 , thereby altering the bow of the resulting modular intramedullary nail  230  as a whole. 
       FIG. 3  illustrates a flow diagram showing a method  300  of connecting male and female nail modules. In describing the method  300 , reference is made to the male nail module  200  and the female nail module  202 . However, those of skill in the art will appreciate that the same basic method may be applied to other embodiments of male and female nail modules. First, the practitioner slides and orients the female connecting end  216  over the male connecting end  206  ( 302 ). If the a key is being used, such as the key  204 , the key is slipped over the elongated section  208 , such that the bottom ridges  228  fit into the notches  215 . Subsequently, the receiving section  218  is inserted over the tips of the prongs  212  of the elongated section  208 . Additionally, the receiving section  218  and the elongated section  208  are oriented relative to each other such that, for example, the notches  222  of the female nail module  202  align with the top ridges  226  of the key  204 . At this point, only minimal force is needed to slide the female connecting end  216  over the male connecting end  206  because the prongs  212  of the elongated section  208  fit loosely within the receiving section  218 . 
     Next, the practitioner continues sliding the female connecting end  216  over the male connecting end  206  while applying some force ( 304 ). As shown in  FIGS. 2F and 2G , the hollowed out center of the receiving section  218  narrows somewhat from the distal end towards the proximal end. Accordingly, some force (e.g., reasonable hand power) must be applied to continue sliding the receiving section  218  over the elongated section  208  because, as the receiving section  218  narrows, the elongated section  208  fits more snugly within the receiving section  218 , particularly due to the slightly wider lips  214  at the ends of the prongs  212 . By applying some force, the prongs  212  may be deflected towards each other by the walls of the receiving section  218  (e.g., due to the slots  210 ), allowing the elongated section  208  to be pushed further into the receiving section  218 . 
     Finally, the practitioner snaps the female connecting end  216  and the male connecting end  206  together ( 306 ). Accordingly, the practitioner continues applying force to push the male nail module  200  and the female nail module  202  together until the lips  214  of the prongs  212  snap into the groove  220  of the receiving section  218 . In certain embodiments, the practitioner must use a connection tool to assist the practitioner in snapping the female connecting end  216  and the male connecting end  206  together (e.g., a tool to assist the practitioner in pressing the receiving section  218  over the last 6 mm of the elongated section  208 ). Additionally, once the female connecting end  216  and the male connecting end  206  are snapped together, the top ridges  226  of the key  204  fit into the notches  222  on the distal end of the female connecting end  216 . 
     In some embodiments, the male nail module  200  and the female nail module  202  may be separable after they have been snapped together. For example, a practitioner may be able to pull the male nail module  200  and the female nail module  202  apart by applying a reasonable force, by using a disconnecting tool, and so on. In other embodiments, once the male nail module  200  and the female nail module  202  are snapped together, the male nail module  200  and female nail module  202  are attached together permanently. 
     However, those of skill in the art will appreciate that a mail nail module and a corresponding, interlocking female nail module may be designed to connect differently than depicted in  FIGS. 2A-2L . For example,  FIGS. 4A-4C  illustrate a male nail module  400 , and  FIGS. 4D-4F  illustrate a female nail module  402 , according to a second exemplary embodiment. To begin with,  FIGS. 4A and 4B  illustrate a side views of the male nail module  400 . Similar to the male nail module  200 , the male nail module  400  includes a male connecting end  406  with an elongated section  408  set off from the rest of the male nail module  400 . As shown in  FIG. 4C , which illustrates a top view of the male nail module  400  (e.g., a view of the proximal end of the male nail module  400 ), at least part of the elongated section  408  is hollowed out, and the elongated section  408  includes four slots  410  formed into the circumference of the elongated section  408 . The four slots  410  accordingly form four prongs  412  into the elongated section  408 , with each prong  412  ending in a lip  414 . Further, as shown in  FIGS. 4A-4C , the edge of the male connecting end  406  at the bottom end (e.g., the distal end) of the elongated section  408  includes a scalloped edge  432 . 
       FIG. 4D  shows a side view of the female nail module  402 , and as shown in  FIG. 4D , the female nail module  402  includes a female connecting end  416 . The female connecting end  416  includes a receiving section  418 .  FIG. 4E  shows a side view of the female nail module  402  with a partial cross-section of the female connecting end  416 , and  FIG. 4F  shows a bottom view of the female nail module  402  (e.g., a view of the distal end of the female nail module  402 ). As shown in  FIGS. 4E and 4F , similar to the receiving section  218 , the receiving section  418  is hollowed out and configured to receive the elongated section  408  of the male connecting end  406 . The receiving section  418  also includes a groove  420  configured to receive the lips  414  of the prongs  412 . Additionally, the distal end of the female connecting end  416  includes a scalloped edge  434  configured similarly to the scalloped edge  432  of the male nail module  400 . 
       FIG. 4G  shows a side view of the male nail module  400  and the female nail module  402  connected together to form a modular intramedullary nail  430 .  FIG. 4H  shows a side view with a partial cross-section of the modular intramedullary nail  430  formed from the connected male nail module  400  and female nail module  402 . As shown in  FIG. 4H , the elongated section  408  of the male connecting end  406  is configured to slide into the receiving section  418  of the female connecting end  416 . The lips  414  of the prongs  412  fit inside the groove  420  and prevent the male connecting end  406  from slipping out of the female connecting end  416 . The scalloped edge  432  of the male nail module  400  is configured to fit and interlock with the scalloped edge  434  of the female nail module  402 . Accordingly, scallops of the interlocked scalloped edges  432  and  434  prevent the male nail module  400  from rotating relative to the female nail module  402 . Additionally, because the scalloped edges  432  and  434  each have a matching, homogenous pattern across their respective edges, the male nail module  400  and female nail module  402  may be aligned relative to each other to produce a variety of anteversions. 
       FIGS. 5A-5C  illustrate a male nail module  500 , and  FIGS. 5D-5G  illustrate a female nail module  502 , according to a third exemplary embodiment. To begin with,  FIGS. 5A and 5B  illustrate side views of the male nail module  500 . As with the male nail modules  200  and  400 , the male nail module  500  includes a male connecting end  506  with an elongated section  508  set off from the rest of the male nail module  500 . The elongated section  508  tapers slightly to an end disk  540  with male anti-rotation features  542 . As illustrated in  FIG. 5A  and in  FIG. 5C , which shows a top view of the male nail module  500  (e.g., a view of the proximal end of the male nail module  500 ), the male anti-rotation features  542  are prongs with a separating space  544 . Referring back to  FIGS. 5A and 5B , the bottom of the elongated section  508  (e.g., the distal end of the elongated section  508 ) also includes a groove  546 . 
       FIGS. 5D and 5E  show side views of the female nail module  502 . Similar to the female nail modules  202  and  402 , the female nail module  502  also includes a female connecting end  516  with a receiving section  518 . As shown, a plurality of slots  548  are formed into the bottom (e.g., the distal end) of the receiving section  518 . The slots  548  are also shown more particularly in  FIG. 5F , which illustrates a side view of the female nail module  502  with a partial cross-section of the female connecting end  516 . As also shown in  FIG. 5F , the receiving section  518  is hollowed out and configured to receive the elongated section  508  of the male connecting end  506 . The receiving section  518  can at least partially be seen through an aperture  550  formed into the wall of the female nail module  502 . As illustrated in  FIG. 5F , the receiving section  518  includes a disk-shaped recess  552  configured to receive the end disk  540  of the male connecting end  506 . Additionally, the receiving section includes female anti-rotation features  554  configured to receive the male anti-rotation features  542 . Referring to  FIG. 5G , which shows a bottom view of the female nail module  502  (e.g., a view of the distal end of the female nail module  502 ), the female anti-rotation features  554  are separated by a protrusion  558  such that the shape of the female anti-rotation features  554  match the shape of the male anti-rotation features  542 . As also shown in  FIG. 5F , a lip  556  is formed into the bottom (e.g., the distal end) of the female connecting end  516 . 
       FIG. 5H  shows a side view of the male nail module  500  and the female nail module  502  connected together to form a modular intramedullary nail  530 . FIGS. SI and  5 J shows side views with partial cross-sections of the modular intramedullary nail  530 , formed from the connected male nail module  500  and female nail module  502 . As shown in  FIGS. 5I and 5J , the elongated section  508  of the male connecting end  506  is configured to slide into the receiving section  518  of the female connecting end  516 . When connected, the male anti-rotation features  542  fit into the female anti-rotation features  554 , thereby preventing the male nail module  500  from rotating relative to the female nail module  502 . The connection of the male anti-rotation features  542  and female anti-rotation features  554  can be at least partially seen by a practitioner through the aperture  550 . Additionally, the lip  556  of the female nail module  502  fits into the groove  546  of the male nail module  500  and locks the female nail module  502  and the male nail module  500  together. 
     Those of skill in the art will appreciate, however, that a male nail module and a female nail module may be designed with different connection mechanisms than depicted in  FIGS. 2A-2L ,  FIGS. 4A-4H , and  FIGS. 5A-5J . For example, the male nail module may instead include a peg that snaps into the female nail module, the male and female nail modules may connect through a spring lock device or a locking screw device, and so on. Moreover, the male and female nail modules may include different engagement mechanisms or features that prevent rotation and/or prevent separation of one module from an adjacent module. As an example, the male nail module may include ribbing or textures on the external surface of the male nail module that create friction once the male nail module has been inserted into the female nail module. This friction then prevents the male nail module from twisting within the female nail module. Alternatively, in some embodiments, the male and female nail modules may not include anti-rotation features. In such embodiments, the male and female nail modules may be rotated with respect to each other until a conformation that matches the fractured bone is reached. In certain embodiments, the male and female nail modules may still further be provided with a sleeve at the junction between the two modules that helps hold the modules together and/or helps prevent the modules from twisting relative to each other. Additionally, in each of the  FIGS. 2A-2L ,  FIGS. 4A-4H , and  FIGS. 5A-5J , the male nail module is shown as the distal half of the resulting intramedullary nail and the female nail module is shown as the proximal half of the resulting intramedullary nail. However, in other embodiments, the male nail module may be the proximal half and the female nail module may be the distal half. 
     In various embodiments, a male nail module (e.g., the male nail module  200 ,  400 , or  500 ) may be connected to a female nail module (e.g., the female nail module  202   402 , or  502 ) to create a modular intramedullary nail that is specific to the anatomy of the fractured bone. For example, a fractured bone may have a specific length, diameter, bow, orientation (e.g., right versus left), and so on. As such, a practitioner may select a male nail module and a female nail module that, when snapped together, form a modular intramedullary nail that suits or matches the length, diameter, bow, orientation, and so on of the bone to be repaired. In this respect, male and female nail modules may be manufactured in different lengths (e.g., to produce modular intramedullary nails between 180 and 500 mm in length), with different diameters (e.g., between 7 and 16 mm in diameter), with different bows (e.g., with different radii of curvature, such as between 3° to 5°), with different angles, for different bone orientations, and so on. 
     Further, the male nail module and the female nail module may be selected based on the type of fracture the modular intramedullary nail is repairing and the type of procedure being used to implant the modular intramedullary nail. To illustrate, with respect to a modular intramedullary nail for the femur, male and female nail modules may be selected based on whether the practitioner wishes to use a trochanter nail (e.g., with reference to  FIG. 1 , for insertion into the femur  100  through the greater trochanter  106 ), a recon nail (e.g., for fixation to the femur  100  by screwing screws through the nail and into the neck  104  and head  102  of the femur  100 ), an antegrade nail (e.g., for insertion into the femur  100  through the proximal end of the femur  100 , such as through the greater trochanter  106 ), a retrograde nail (e.g., for insertion into the femur  100  through the distal end of the femur  100 , such as between the condyles  110 ), and so on. Accordingly, the male nail module and/or the female nail module may be selected based on the configuration of the screw holes in the male nail module and/or female nail module and the locations in the bone to which the resulting modular intramedullary nail may be affixed with screws threading through the screw holes (e.g., the “fixation points” in the bone). 
     To illustrate,  FIGS. 6A-6D  show examples of nail modules with various screw hole configurations that may be used in to create different types of modular intramedullary nails. In describing  FIGS. 6A-6D , and the modular intramedullary nails that may be created using the nail modules shown in  FIGS. 6A-6D , reference is made to the femur  100  shown in  FIG. 1 . To begin with,  FIG. 6A  shows a female nail module  600 , similar to the female nail module  502 , with two fixation holes  602   a  and  602   b  configured such that screws  604   a  and  604   b  threaded through the fixation holes  602   a  and  602   b.  respectively, point diagonally upwards. In one example, the module  600  is selected to create the proximal end of a recon nail, as the screws  604   a  and  604   b  can be angled through module  600  and into the neck  104  and head  102  of the femur  100  to fix the recon nail in the femur  100 . 
       FIG. 6B  shows a female nail module  700 , similar to the female nail module  502 , with a single fixation hole  702  configured such that a screw  704  threaded through the fixation hole  702  points diagonally downwards. As such, the module  700  may be selected to create the proximal end of a standard trochanteric nail. With the module  700  as the proximal end of a standard trochanteric nail, the screw  704  can angle downward through the module  700  and between the greater trochanter  106  and lesser trochanter  108  of the femur  100 , thereby fixing the standard trochanteric nail to the femur  100 . 
       FIG. 6C  shows a male nail module  800 , similar to the male nail module  500 , with fixation holes  802   a  and  802   b.  Fixation holes  802   a  and  802   b  are configured such that screws  804   a  and  804   b  threaded through the fixation holes  802   a  and  802   b.  respectively, point horizontally (e.g., perpendicular to the body of the male nail module  800 ). In one example, the module  800  is selected to form the distal end of a recon nail, as the screws  804   a  and  804   b  can be threaded through the module  600  and into the inferior portion of the femur  100  near the condyles  110  (e.g., similar to the intramedullary nail  118  shown in  FIG. 1 ). In another example, the male nail module  800  may instead be a female nail module and selected to form the proximal end of a retrograde nail, with the screws  804   a  and  804   b  again fixing the retrograde nail in the inferior portion of the femur  100  near the condyles  110  or through the condyles  110 . 
       FIG. 6D  shows a male nail module  900 , similar to the male nail module  500 , with three fixation holes  902   a,    902   b,  and  902   c  configured such that screws  904   a,    904   b.  and  904   c  threaded through the fixation holes  902   a,    902   b,  and  902   c,  respectively, point horizontally (e.g., perpendicular to the body of the male nail module  900 ). However, as shown in  FIG. 6D , fixation holes  902   a  and  902   c  are configured such that the screws  904   a  and  904   c  lie in a first plane, and fixation hole  902   b  is configured such that the screw  904   b  lies in a second plane. The module  900  may be selected, for example, to form the distal end of a standard trochanteric nail such that the screws  904   a,    904   b,  and  904   c  anchor the distal end of the nail into the femur  100  near the condyles  110 . 
     Those of skill in the art will appreciate, however, that modules  600 ,  700 ,  800 , and  900  shown in  FIGS. 6A-6D  are example modules. For example, modules may be designed to have additional or fewer fixation points compared to modules  600 ,  700 ,  800 , and  900  shown in  FIGS. 6A-6D . Additionally, modules may be designed to have fixation points allowing for different screw angles and/or screw sizes than those shown in  FIGS. 6A-6D , and modules may be designed for long bones other than the femur (e.g., the tibia or humerus) or other bones (e.g., an ankle fusion surgery). Further, while modules  600  and  700  may be designed as male nail modules, and modules  800  and  900  may be designed as female nail modules. 
     Modules may also be designed with various tip conformations configured to facilitate the implantation of a modular intramedullary nail. For example, as shown in  FIGS. 2A and 2K , the proximal end of the female nail module  202  includes a connecting screw notch formed therein. The connecting screw notch is configured to receive a connecting screw used as part of the implantation procedure of the modular intramedullary nail  230  into the fractured bone. Once the modular intramedullary nail  230  is implanted, the connecting screw may be removed from the connecting screw notch and replaced, for example, with an end cap configured to screw into the connecting screw notch and seal off the connecting screw notch. As another example, as also shown in  FIGS. 2A and 2K , the distal end of the male nail module  200  designed with a tapered tip conformation. Those of skill in the art will further appreciate, however, that modules may be manufactured with a variety of different tip conformations designed to facilitate the implantation of a modular intramedullary nail. For example, modules may be designed to serve as the distal end of a nail and include distal tip conformations such as a pointed tip, a screw tip, a threaded tip, a rounded tip, and so on. Alternatively, modules may be designed with flat tips, such as the tips shown in the male and female modules  500  and  502 , as shown in  FIG. 5H . 
     Additionally, in certain embodiments, a nail module may include further modifications or be adapted with further capabilities. As an illustration, in some embodiments, a nail module may be configured to deliver a therapeutic, such as a medication, a growth factor, and so on, to a specific portion of bone. The therapeutic may either be delivered from an internal section of the nail module or from an external section of the nail module. For example, in one embodiment, a therapeutic is stored in an internal cavity of the nail module and elutes into the bone via the screw holes of the nail module or via pores formed into the body of the nail module. In another embodiment, the nail module includes one or more external compartments or absorptive areas in which a therapeutic is stored, and the therapeutic elutes into the bone from the external compartment(s) or absorptive area(s). In yet another embodiment, the nail module includes a coating of the therapeutic on the external surface of the nail module. 
     Furthermore, in some embodiments, a nail module may be configured to allow the delivery of an electric current to the tissue surrounding the nail module. The nail module as a whole may serve as an electrode for the delivery of the electric current (e.g., because the nail module is made from a conductive material), or the nail module may include one or more separate electrodes formed into the body and/or ends of the nail module for the delivery of the electric current. Alternatively, or additionally, a nail module may be configured to allow the delivery of a magnetic field to the tissue surrounding the nail module. In these embodiments, the nail module may, for example, be configured to be connected to an external power source for generating the electric current and/or magnetic field. As another example, the nail module may include an internal power source (e.g., designed to fit inside a cavity of the nail module) for generating the electric current and/or magnetic field that may be rechargeable by an external power source. 
     In various embodiments, modular intramedullary nails may be created using more than two modules. For example, nail modules may be manufactured that include both a male connecting section and a female connecting section (e.g., both the male connecting end  206  and the female connecting end  216 ). These nail modules may serve as the shaft of a modular intramedullary nail, with a male nail module and a female nail module forming the proximal and distal ends of the modular intramedullary nail. Accordingly, one or more shaft nail modules may be connected to a male nail module and a female nail module, for example, to change the length or bow of an intramedullary nail. As an example, a shaft nail module with a bow of 3° to 5° may be connected between two straight male and female nail modules to create a modular intramedullary nail that matches the bow of a femur of a patient. Alternatively, several shaft nail modules may be connected between two straight male and female nail modules, with just one of the shaft nail modules having a bow or angle sufficient to change the overall bow or angle of the resulting modular intramedullary nail. As another example, shaft nail modules of various lengths may be provided to a practitioner such that the practitioner can connect shaft nail modules between a male nail module and a female nail module until the length of the resulting modular intramedullary nail matches the length of a humerus of a patient. 
     Further, in various embodiments, different male nail modules, female nail modules, and/or shaft nail modules may be provided in a kit such that the practitioner can create a modular intramedullary nail that is customized to the anatomy of the fractured bone, the type of fracture, and the surgery that will be used to stabilize the fracture. For example, in one embodiment, a kit may include twenty to fifty modules with different diameters (e.g., ranging between 7 and 16 mm in diameter), lengths (e.g., such that modular intramedullary nails between 180 and 500 mm in length may be created), and radii of curvature (e.g., between 3° and 5°). Additionally, the male nail modules and female nail modules may be configured with various fixation holes configured for various numbers of fixation screws and fixation angles. The practitioner can select male and female nail modules to serve as the proximal and distal ends of the modular intramedullary nail, where the male and female nail modules will create the appropriate fixation points for the intramedullary nail in the context of the fractured bone, the type of fracture being stabilized, and the surgery being used to implant the intramedullary nail. The practitioner can then build out the shaft of the modular intramedullary nail between the selected male and female nail modules by selecting shaft nail modules having the appropriate length and bow to match the anatomy of the bone being stabilized. In some embodiments, a kit of nail modules may be for a specific bone (e.g., a femur, a tibia, a humerus, or an ankle). In other embodiments, a kit of nail modules may be designed such that modular intramedullary nails configured to be implanted in a variety of bones may be created. 
     Those of skill in the art will appreciate that, although reference is primarily made herein to modular intramedullary nails used to treat fractured femurs, modular intramedullary nails may also be designed for a variety of other long bones. For example, modular intramedullary nails may be designed to treat fractured tibias, fibulas, humeruses, radiuses, ulnas, and so on. Modular nails may also be designed for other fixation purposes, such as to be used in an ankle fusion surgery. Additionally, modular intramedullary nails may be designed to treat a variety of fractures within a bone. As an illustration, modular intramedullary nails for a femur may be designed to treat intertrochanteric fractures, subtrochanteric fractures, pertrochanteric fractures, femoral shaft fractures, supracondylar factures, and so on. 
     Various exemplary embodiments of the invention are described herein. Reference is made to these examples in a non-limiting sense. They are provided to illustrate more broadly applicable aspects of the invention. Various changes may be made to the invention described and equivalents may be substituted without departing from the true spirit, and scope of the invention. In addition, many modifications may be made to adapt a particular situation, material, composition of matter, process, process act(s) or step(s) to the objective(s), spirit or scope of the present invention. Further, as will be appreciated by those with skill in the art, each of the individual variations described and illustrated herein has discrete components and features which may be readily separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of the present inventions. All such modifications are intended to be within the scope of claims associated with this disclosure. 
     The invention includes methods that may be performed using the subject devices. The methods may include the act of providing such a suitable device. Such provision may be performed by the end user. In other words, the “providing” act merely requires the end user obtain, access, approach, position, set-up, activate, power-up, or otherwise act to provide the requisite device in the subject method. Methods recited herein may be carried out in any order of the recited events that is logically possible, as well as in the recited order of events. 
     Exemplary aspects of the invention have been set forth above. As for other details of the present invention, these may be appreciated in connection with patents and publications generally known or appreciated by those with skill in the art. The same may hold true with respect to method-based aspects of the invention in terms of additional acts as commonly or logically employed by those with skill in the art. 
     In addition, though the invention has been described in reference to several examples optionally incorporating various features, the invention is not to be limited to that which is described or indicated as contemplated with respect to each variation of the invention. Various changes may be made to the invention described and equivalents (whether recited herein or not included for the sake of some brevity) may be substituted without departing from the true spirit and scope of the invention. In addition, where a range of values is provided, it is understood that every intervening value, between the upper and lower limit of that range and any other stated or intervening value in that stated range, is encompassed within the invention. 
     Also, it is contemplated that any optional feature of the inventive variations described may be set forth and claimed independently, or in combination with any one or more of the features described herein. Reference to a singular item, includes the possibility that there are plural of the same items present. More specifically, as used herein and in claims associated hereto, the singular forms “a,” “an,” “said,” and “the” include plural referents unless specifically stated otherwise. In other words, use of the articles allow for “at least one” of the subject item in the description above as well as claims associated with this disclosure. It is further noted that such claims may be drafted to exclude any optional element. As such, this statement is intended to serve as antecedent basis for use of such exclusive terminology as “solely,” “only” and the like in connection with the recitation of claim elements, or use of a “negative” limitation. 
     Without the use of such exclusive terminology, the term “comprising” in claims associated with this disclosure shall allow for the inclusion of any additional element—irrespective of whether a given number of elements are enumerated in such claims or the addition of a feature could be regarded as transforming the nature of an element set forth in such claims. Except as specifically defined herein, all technical and scientific terms used herein are to be given as broad a commonly understood meaning as possible while maintaining claim validity. 
     For the purpose of this disclosure, the term “coupled” means the joining of two members directly or indirectly to one another. Such joining may be stationary or moveable in nature. Such joining may be achieved with the two members or the two members and any additional intermediate members being integrally formed as a single unitary body with one another, or with the two members or the two members and any additional intermediate members being attached to one another. Such joining may be permanent in nature or may be removable or releasable in nature. 
     The breadth of the present invention is not to be limited to the examples provided and/or the subject specification, but rather only by the scope of claim language associated with this disclosure.