Patent Abstract:
Medical kits for treating fractures in or adjacent the wrist and distal forearm employ an intramedullary interlocking fixation rod (i.e, it interlocks the distal and proximal fracture fragments together) to stabilize the skeletal structure in a manner which can inhibit the amount of collapse or loss in skeletal length exhibited by a patient with a distal radius fracture.

Full Description:
RELATED APPLICATIONS  
       [0001]     This application is a divisional of U.S. patent application Ser. No. 10/377,255, filed Feb. 28, 2003, which is a continuation of U.S. Pat. No. 6,527,775, filed Sep. 22, 2000, the contents of which are hereby incorporated by reference as recited in full herein. 
     
    
     FIELD OF THE INVENTION  
       [0002]     This invention relates to devices and methods for treating distal radius fractures.  
       BACKGROUND OF THE INVENTION  
       [0003]     Distal radius fractures are among the most common type of bone fracture of the upper extremities. The distal radius fracture is often called a “Colles” fracture (named after a 19 th  Century British surgeon who described the fracture). The Colles fracture is associated with a fracture of a distal tip or distal end portion of the radius.  
         [0004]     Distal radius fractures are, unfortunately, most common in the elderly segment of the population. This is because the elderly tend to exhibit some degree of bone density loss or osteoporotic condition making their bones more susceptible to injury. Indeed, just as osteoporosis is known to affect women more often and more severely than men, distal radius fractures are much more common in females than males, typically on the order of about 20:1. Distal radius fractures generally occur as a result of a fall, because the patient tends to brace for the fall by outstretching the hand which then fractures upon impact, at the distal radius at or adjacent the wrist.  
         [0005]     As shown in  FIGS. 1 and 2 , the distal radius fracture is such that the major fracture line  15  associated with this type of injury generally occurs just above or proximal to the articular joint surface  11  of the distal radius at the wrist about the metaphysis  12 . As shown in  FIGS. 1 and 2 , one common distal radius fracture type separates the shaft  13  of the radius  10  from the distal end portion of the bone. That is, the fracture line  15  defines a first major bone fragment  18  which is located above the fracture line  15  (the distal side) proximate the articular joint surface  11  and extends substantially medially (laterally) across the radius  10  in the metaphysis region. Although not shown, the fracture may also produce smaller bone fragments or splinters along the fracture line. Further, the distal end portion of the radius may be present as multiple (vertically and/or horizontally oriented) fragments disrupting the articular joint surface itself. This latter type of Colles fracture is known as a comminuted intraarticular fracture (not shown).  
         [0006]      FIG. 1  illustrates the fracture line  15  in the radius  10  as a substantially horizontal line which produces an upper or distal fracture fragment  18  as a substantially unitary fragment. Similarly,  FIG. 2  illustrates a fracture line  15  in the radius  10  which is offset from a horizontal axis.  
         [0007]     Distal radius fractures can be difficult to treat, particularly in the older osteoporotic patient. Conventionally, this type of fracture has been treated by a closed (non-surgical) reduction and application of a splint (such as a plaster compression dressing) or a cast (typically circular plaster or fiberglass). Unfortunately, primarily because of the patient&#39;s osteoporosis, during the healing process, and despite the splint/cast immobilization, the fracture fragments can settle, potentially causing a collapse at the fracture line in the distal radius.  FIG. 2  illustrates a loss of radial inclination (in degrees) and a shortened length in the skeletal length line (shown with respect to a neutral length line “L”) which can occur after a fracture in the distal radius. That is, even healed, these types of fractures may cause shortening or collapse of the bone structure relative to the original skeletal length line. This, in turn, can result in deformity and pain.  
         [0008]     Treatment options for a collapsed distal radius fracture are relatively limited. The primary conventional treatments include the use of devices which can be characterized as either external fixation devices or internal fixation devices. External fixation devices are those that stabilize a fracture through the use of percutaneous pins which typically affix one or more bone portions to an external (anchoring or stabilizing) device. Internal fixation devices are those devices which are configured to reside entirely within the subject (internal to the body). Percutaneous pins can be used alone, without anchoring devices, for fixation of Colles type fractures. The use of external devices has conventionally been thought to be particularly indicated in cases of bone toss to preserve skeletal length as noted, for example, in U.S. Pat. No. 5,571,103 to Bailey at col. 1, lines 35-43. However, such devices can be bulky, cumbersome, and or invasive to the user or patient. Further the external fixation devices may not be suitable for use in soft osteoporotic bone.  
         [0009]     In view of the foregoing, there remains a need for improved distal radius fracture treatment devices and techniques.  
       SUMMARY OF THE INVENTION  
       [0010]     In a preferred embodiment the present invention provides methods and devices for treating fractures in or adjacent the wrist and distal forearm. The present invention is particularly useful for stabilizing and treating distal radius fractures of a patient. The devices and methods of the present invention employs an intramedullary interlocking fixation rod (i.e, it interlocks the distal and proximal fracture fragments together) to stabilize the skeletal structure in a manner which can inhibit the amount of collapse or loss in skeletal length exhibited by a patient with a distal radius fracture. The devices and methods of the present invention may be especially useful for treating distal radius fractures in subjects with osteoporosis.  
         [0011]     One aspect of the invention is a method for treating a distal radius fracture of a patient comprising the use of an internal fixation rod. As noted above, the radius anatomically has an articular joint surfaces a metaphysis region, a shaft portion and a medullary canal associated therewith. The distal radius fracture has a fracture line which divides the radius into a distal fracture fragment portion and a proximal fracture fragment portion. The distal fragment portion includes the distal end of the radius proximate the articular joint surface, and the distal portion of the fracture has a width thereacross. The method comprises the steps of: (a) installing an elongated rod having opposing proximal and distal portions into the medullary canal of the patient such that the proximal portion of the rod resides above the fracture line (closer to the elbow) and the distal portion of the rod resides below the fracture line (closer to the hand); (b) securing a distal fixation member to the elongated rod and into the distal end portion of the radius at a location which is below the fracture line such that the distal fixation member extends internal of the patient substantially laterally across a portion of the width of the distal fracture fragment; and (c) anchoring the elongated rod inside the medullary canal of the radius at a location which is above (distal to) the fracture line.  
         [0012]     Another aspect of the present invention is an internal fixation device for eating or repairing distal radius fractures having a fracture line forming distal and proximal fracture fragments. The radius is anatomically configured with a distal articular joint surface, a metaphysis region, a shaft, and a medullary canal. The anatomic position of the hand is palm forward or front such that the medial orientation is next to the body (fifth finger or ulna side of hand) and the lateral orientation is away from the body (thumb or radial side). Generally stated, the distal portion of the radius has a width which extends across (a major portion of) the arm from the medial side to the lateral side. The device includes an elongated fixation rod having opposing proximal and distal portions. The distal portion includes a head with a laterally extending distal aperture formed therein, and the proximal portion comprises at least one proximal aperture formed therein. The elongated fixation rod proximal portion is sized and configured such that, in position, it resides in the shaft inside a portion of the medullary canal of the radius of a patient. The device also includes a distal fixation member configured to enter the distal aperture and attach to the rod and the distal fracture fragment to hold the distal portion of the rod to the distal fracture fragment. The device further includes at least one proximal fixation member, a respective one for each of the at least one proximal apertures. The proximal fixation member is configured to secure the lower portion of the fixation rod to the radius at a position which is distal to the fracture line. In position, the elongated fixation rod is configured to reside within the radius, and the distal fixation member and the at least one proximal fixation member are configured to reside internal of the body of the patient.  
         [0013]     In a preferred embodiment, the elongated fixation rod has a curvilinear profile. The curvilinear profile includes a distal curve portion at the distal portion of the device. The distal curve portion is adapted to accommodate the radial styloid region of the radius proximate the articular joint surface. The rod can also be provided as a plurality of segments matable or attachable. In one embodiment an intermediate segment can be provided in different lengths to allow for the adjustment of length according to a patient&#39;s anatomical considerations. Of course, the rod can be a unitary body provided in a number of standard sizes preferably statistically representative of the treatment population.  
         [0014]     The foregoing and other objects and aspects of the present invention are explained in detail in the specification set forth below. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]      FIG. 1  is an anterior-posterior view of a distal radius fracture illustrating a fracture line proximate the articular joint surface.  
         [0016]      FIG. 2  is an anterior-posterior view of a distal radius fracture similar to that shown in  FIG. 1 . This figure illustrates an alternatively configured fracture line proximate the articular joint surface.  
         [0017]      FIG. 3A  is an anterior-posterior view of an intramedullary fixation rod attached to the radius for treating a distal radius fracture according to an embodiment of the present invention.  
         [0018]      FIG. 3B  is an exploded view of the distal fixation attachment member shown inserted into the fixation rod in  FIG. 3A  according to one embodiment of the present invention.  
         [0019]      FIG. 4  is a front schematic view of the distal fixation rod of  FIG. 3A  in position as an internal fixation device held within the body of the patient according to one embodiment of the present invention.  
         [0020]      FIG. 5A  is a lateral view of an intramedullary rod configured to interlock or affix the bone fragments of a distal radius fracture according to one embodiment of the present invention.  
         [0021]      FIG. 513  is a cross-sectional view of the rod shown in  FIG. 5A  taken along line  5 B- 5 B.  
         [0022]      FIG. 6  is a perspective view of an intramedullary fixation device according to one embodiment of the present invention.  
         [0023]      FIG. 7  is a side view (shown oriented anterior to posterior) of an alternate embodiment of an intramedullary system according to the present invention.  
         [0024]      FIG. 8  is a side view (shown oriented anterior to posterior) off another embodiment of an intramedullary system according to the present invention.  
         [0025]      FIG. 9A  is a front anterior-posterior view of an alternate embodiment of a distal fixation rod according to the present invention.  
         [0026]      FIG. 9B  is an exploded view of the biked or multi-segment according to  FIG. 9A .  
         [0027]      FIG. 9C  is a front view of a set of intermediate rod segments according to an embodiment of the present invention.  
         [0028]      FIG. 10  is a schematic side view of an intramedullary system with an external detachable positioning guide according to an embodiment of the present invention.  
         [0029]      FIG. 11  is a block diagram of the steps of treating a distal radius fracture according to one embodiment of the present invention.  
         [0030]      FIG. 12  is perspective view of the arm of a patient illustrating a sigmoid or longitudinal incision over the radial styloid area.  
         [0031]      FIG. 13  is an enlarged schematic view of the incision site in the patient shown in  FIG. 12  to illustrate preparation of the site for positioning intramedullary fixation rods for distal radius fractures according to an embodiment of the present invention.  
         [0032]      FIG. 14  is an enlarged schematic view of the incision site shown in  FIG. 13  illustrating that a small bone window may be made or formed into the radius such that it extends across the fracture site according to the present invention.  
         [0033]      FIG. 15A  is an anterior-posterior view of the bone window shown in  FIG. 14 ,  
         [0034]      FIG. 15B  is a schematic view of the prepared bone site shown in  FIG. 15A  illustrating the use of a sound or broach instrument which is sized and configured to be inserted into the intramedullary canal of the radius to determine size and/or open or prepare the canal to receive a fixation rod according to an embodiment of the present invention.  
         [0035]      FIG. 16  is a top anterior-posterior view of an intramedullary fixation rod assembled to a rod driver and screw attachment guide according to one embodiment of the present invention.  
         [0036]      FIG. 17  is a side (lateral) view of the device shown in  FIG. 16 .  
         [0037]      FIG. 18  is a side of the device shown in  FIGS. 16 and 17  showing the device in position in the patient.  
         [0038]      FIG. 19  is a top anterior-posterior view of the device shown in position in  FIG. 18 .  
         [0039]      FIG. 20  is a schematic view of the fixation rod in position in the subject according to an embodiment of the present invention.  
     
    
     DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0040]     The present invention will now be described more fully hereinafter with reference to the accompanying figures, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Like numbers refer to like elements throughout. In the figures, certain layers, regions, or components may be exaggerated for clarity.  
         [0041]     As shown in  FIG. 3A , in a preferred embodiment, the intramedullary fixation device  25  includes an elongated axially extending rod  26  with a distal portion  27  and a proximal portion  28 . The device  25  also includes a distal fixation member  30  and at least one proximal fixation member  35  (shown as two proximal fixation members  35   a ,  35   b ). The rod  26  includes a head  26   h  at the distal end portion  27  of the rod  26 . A distal aperture  30   a  is formed into the head  26   h  of the distal portion such that it extends across the width of the rod  26 .  
         [0042]     As shown, the distal fixation member  30  is configured to enter and extend through and beyond the distal aperture  30   a  to engage with the distal fracture fragment  18  and secure the rod  26  and the distal fracture fragment  18  theretogether. Preferably, the distal fixation member  30  is sized to extend across a major portion of the width of the distal fracture fragment  18 . More preferably, the distal fixation member  30  is sized with a length which is sufficient to extend across substantially all of the fracture fragment  18  so as to provide support for the radial, center, and ulna aspects of the distal fracture fragment  18  (the ulna aspect being the part of the fracture fragment adjacent or proximate the ulna  14  while the radial aspect being the portion of the fracture fragment on the opposing side of the view shown in  FIG. 3A  and the center aspect being the portion in between).  
         [0043]      FIG. 3B  illustrates the distal fixation member  30  apart from the rod  26 . The distal fixation member  30  can be configured as any suitable attachment means to secure the distal fracture fragment  18  to the rod  26 , while also providing lateral structural reinforcement. For example, but not limited to, the attachment means can be one or more of a pin, nail, threaded or partially threaded member such as a screw, or a combination of the above.  FIG. 3B  illustrates the distal fixation member  30  as having, in serial order, from one end to the other, a head portion  30   h , a threaded portion  30   th , and a pin portion  30   p.    
         [0044]     In one embodiment, as shown in  FIG. 3A , the head of the distal fixation member  30   h  extends beyond the edge of the body of the rod  26 . However, as schematically shown in  FIG. 7 , the aperture  25   a  can be configured (such as with a countersunk or recessed portion configured with a depth sufficient to receive the head  30   h  therein) such that upon assembly, the distal fixation member head  30   h  is substantially flush or recessed with the outer contour or profile of the rod  26 .  FIG. 3A  also illustrates that, in position in the patient, the distal fixation member  30  is preferably configured to directly abut the outer surface of the rod  26 .  FIG. 6  is a perspective view of one embodiment of the intramedullary fixation device  25 . This embodiment shows that the rod  26  is configured as a unitary body with a recess to receive the head  30   h  of the distal fixation member  30 .  
         [0045]     In a preferred embodiment, the rod  26  is configured with a profile  26   p  which is curvilinear when viewed from the anterior-posterior view, as shown, for example, in  FIGS. 3A and 4 . As shown, the proximal portion of the rod  28  is substantially linear and is configured to anally extend within the medullary canal of the patient in the radial shaft. As the rod  26  approaches the metaphysis region ( 12 ,  FIG. 1 ) it gradually curves from the substantially linear axial extending portion so as to position the distal end  27   e  of the rod  26  proximate the radial styloid region of the distal radius. Preferably, the rod  26  is configured to follow the contour line of the radius as it transitions from the proximal portion  28  having a substantially linear contour in the shaft region to the distal portion  27  which has a curvilinear or slight arcuately contoured shape proximate the metaphysis region.  
         [0046]      FIGS. 3A and 4  also illustrate that the head  26   h  of the rod  26  is preferably configured with a body which has an increased perimeter or area size with respect to the proximal  28  portion of the rod  26 . It is also preferred that the distal end of the head  26   h  be beveled or inclined  27   i . As shown, the tip or end of the head  26   b  lopes downwardly from the side surface adjacent the radial portion toward the ulna aspect of the fracture fragment  18 .  
         [0047]     It is additionally referred that the distal aperture  30   a  be formed in the rod  26  such that it allows the distal fixation member  30  to extend therethrough and reside at a position which is angularly offset tore the axial is. As show in  FIG. 3A , the axial axis is coincident with the centerline of the proximal portion of the rod (indicated by the letter “a” in  FIG. 3A ). Preferably, the distal fixation member  30  extends at a position which is less than about ninety degrees, and preferably between about 10 degrees to less than about 90 degrees, away from the axial axis, such that it is approximately in-line with the articular surface.  
         [0048]     In this embodiment, the head  26   h  of the rod  26  can buttress the distal radius region and increase the structural effectiveness of the rod. Thus, together with the proper positioning of the distal portion  27  of the rod  26  in the distal radius and/or the medial extension of the distal fixation member  30 , the head  26   h , can reinforce or positively affect the structural integrity of the device to help support the radial styloid region of the distal fracture fragment.  
         [0049]     Referring again to  FIG. 3A  and  FIG. 4 , at least one, and preferably two or more, proximal fixation members  35  are used to secure the rod  26  to the shaft region  13  of the radius  10  at the lower or proximal portion of the rod  26 .  FIG. 3A  illustrates the use of two similarly sized proximal fixation members  35   a ,  35   b , respectively, while  FIG. 4  illustrates the use of one  35 . Preferably, as shown in  FIG. 5A , the proximal fixation members  35   a ,  35   b  are respective self-tapping screws positioned on the rod  26  such that they are proximate to each other. However, pins, nails, or other attachment means (as well as numbers and positioning of same) can also be used as will be appreciated by one of skill in the art. It will be appreciated, by those of skill in the art, that the proximal fixation members  35  and corresponding apertures  25   a  are primarily used to inhibit shortening of the skeletal structure. As shown in  FIG. 5A , the proximal fixation member  35  transversely extends in serial order, through a portion of the radius shaft, through a corresponding proximal receiving aperture  25   a  formed in the rod  26 , and then into an opposing portion of the radius shaft to thereby secure or locate and hold the proximal portion of the rod  25  relative to the radius, the proximal fixation member having a length and opposing ends sized and configured accordingly  36 ,  38 .  
         [0050]      FIG. 4  schematically illustrates the preferred post-operative position of the intramedullary fixation device  25  in the patient. That is, post-operatively in position in the patient, the rod  26  and distal and proximal fixation members  30 ,  35  are held within the body of the subject such that the device  25  is an internal fixation device and is devoid of externally located coupling or fixation members.  
         [0051]     As shown in  FIG. 4 , the rod  26  is installed into the medullary canal of the patient such that the distal portion  27  of the rod  26  resides distal to the fracture line  15  (but substantially within the distal radius, preferably so as to reside proximal to the articular joint surface  11 ) and the bottom or proximal portion  28  of the rod  26  extends through and resides proximal to the fracture line  15 . The distal fixation member  30  is secured to the rod  26  and to the distal end portion of the radius at a location which is distal to the fracture line  15  in the metaphysis region of the distal radius. As is also shown, the distal fixation member  30  extends (to reside internal of the body of the patient) substantially transversely across a portion of the width of the distal fracture fragment  18 . The device  25  may not be preferred for use with commuted distal radius fractures.  
         [0052]     In position, the rod  26  is configured such that it also extends through a portion of the medullary canal to terminate therein in the shaft region  13  of the radius  10  ( FIG. 1 ) (at a location which is proximally spaced away from the fracture line  15 ). The proximal portion  28  of the rod  26  is anchored to the radius so as to reside inside the medullary canal of the radius. The proximal portion  28  of the rod  26  is fixed in position relative to the shaft of the radius by the use of at least one pin, screw, or the like, as discussed above. As is also noted above, it is more preferred that two (and potentially three or more) to provide increased structural stability so as to inhibit the propensity of the rod  26  to toggle or move distally with the distal fragment.  
         [0053]      FIG. 4  also illustrates that the proximal end of the rod  28   e  may be configured with a reduced cross-sectional size or tapered perimeter relative to the portion of the rod  26  thereabove to allow for ease of insertion into the patient. Preferably, as shown, the proximal end of the device  28   e  is substantially pointed.  
         [0054]      FIG. 5A  illustrates the rod  26  with a length “L”, a width “W” and a thickness “T”. It is envisioned that the rod  26  be provided or be made available for use in a plurality of lengths and widths so that the clinician can select the appropriate dimensions according to the particular anatomical needs of the patient. Preferably, for the distal radius fracture, the length of the rod  26  is between about 2-5 inches long, and more preferably between about 2.5 inches-4.0 inches long. It is also preferred that the width of the rod  26  be provided in an arrangement of incremental sizes. It is thought that suitable widths may be between about 2-8 mm in width and more preferably between about (2.5-4 mm) in width.  
         [0055]     As shown in  FIG. 5B , the rod  26  is held in the medullary canal of the radius of the patient. The lower or proximal portion  28  of the rod  26  is preferably held substantially centrally in the shaft portion  13  of the radius  10 . In one embodiment, the cross sectional shape of the rod  26  is rectangular. The rod  26  can be configured with other cross-sectional shapes, such as, but not limited to, circular, oval, square, triangular, and hexagon. It is also preferred that in designs with sharp edges, that the edges be radiused (“break edges”) to reduce the likelihood of stress fractures in the rod  26  (or in the bone adjacent the rod). Further, the distal portion  27  of the rod  26  may have a different cross-sectional shape and configuration from the proximal portion  28  of the rod  26 . For example, the proximal portion  28  of the rod  26  may have a circular shape with the addition of a ribbed portion on one side to inhibit rotation once in the intramedullary canal in the radius of the patient, while the distal portion  27  of the rod  26  can have an oval or rectangular shape (not shown).  
         [0056]      FIG. 7  illustrates another embodiment of an intramedullary fixation device  25 ′ according to the present invention. In this embodiment, the rod  26  is configured as first and second attachable segments or links  127 ,  128 . As shown, the distal segment  127  of the rod  26  is configured with the head of the rod  26   h  while the proximal portion  128  is again configured to reside in the medullary canal of the radius shaft. The two segments  127 ,  128  are configured to align ad mate together to define the rod  26 . As shown in  FIG. 7 , a linking screw  120  is inserted into a threaded aperture  120   a  that it spans the first and second segments  127 ,  128  when aligned. Of course, other attachment means or segment link configurations can also be used, such as, but not limited to, bayonet type fittings, friction fit or threaded matable female/male components, and the like.  
         [0057]      FIG. 8  illustrates another embodiment of an intramedullary fixation device  25 ″ for the radius according to the present invention. In this embodiment the rod  26  includes a proximal extension  28   ext . As shown, the proximal extension  28   ext  is tapered adjacent the proximal end portion  28  of the rod  26 . The extension  28   ext  is configured to reside in a more proximal portion of the radius shaft (away from the hand and closer to the elbow). This embodiment may also be used in the absence of a distal radius fracture to treat proximal radius fractures.  FIG. 8  also illustrates that the distal fixation member  30  is oriented at about 45 degrees with respect to the axial axis. In any event, this configuration can allow for additional support in the shaft region of the radius (i.e., more proximal “purchase”)  
         [0058]      FIG. 9A  illustrates a rod  26  having a body with multiple segments or links  127 ′,  129 ,  128 ′. As shown, in this embodiment, the rod  26  is defined by three segments, the distal segment  127 ′, an intermediate segment  129 , and a proximal segment  128 ′.  FIG. 9B  illustrates that, in this embodiment, the distal segment  127 ′ includes a protrusion  127   p ′ while the upper portion of the intermediate segment  129  includes a recess  129   r  configured and sized to matably and/or securely receive the protrusion  127   p ′ therein. Similarly, the proximal segment  128 ′ includes a recess  128   r ′ formed therein configured to receive the intermediate segment protrusion  129   p  therein. Preferably, the segments  127 ′,  129 ,  128 ′ are sized and configured to be held together by a frictional fit of the interlocking or mating components, however, a biocompatible adhesive can also be used, as desired. Other attaching means can also be used to secure the segments together as will be appreciated by those of skill in the art. For example, the protrusion  127   p ′ can be threaded and configured to threadably engage with a threaded recess  129   r  formed in the upper portion of the intermediate segment  129 . Similarly, the proximal recess  128   r ′ can be threaded and configured to threadably engage with the intermediate segment  129   p  protrusion (which can be configured as a correspondingly configured male threaded component).  
         [0059]     As shown in  FIG. 9C , the intermediate segment  129  can be provided in an assortment of lengths to allow the rod  26  to be adjusted to a desired length according to the anatomical considerations of the patient. Alternatively, the intermediate segment  129  can be a plurality of similarly sized or different, incrementally sized segments. In this way, the distal and proximal segments  127 ′,  128 ′ can be provided as standardized-length components with the intermediate segment  129  providing an adjustable length. Thus, the clinician can custom fit the rod  26  at the use site. That is, the clinician can assess the patient and then determine the appropriate number or size of intermediate segments  129  to be used dependant on the length desired. This custom fit does not require the use of a preformed rod or a special order rod. Rather, the fit can be carried out at the clinic, use, or instillation site (proximate in time or contemporaneous with the treatment) to fit the number and size components together according to the needs of the patient. Alternatively, the distal and/or proximal segments  127 ′,  128 ′ can also (or alternatively) be configured as or provided in different lengths.  
         [0060]      FIG. 10  illustrates the use of an insertion or positioning guide  150  affixed to the distal end portion  27  of the rod  26  to allow for ease of insertion and placement into the patient. As shown, the guide  150  includes an axially (or longitudinally) extending arm  151  which is configured to reside external of the body of the patient when the rod  26  is inserted into the intramedullary canal. As is also shown, the guide arm  151  includes a visual locating, means or visual indicia  153 ,  155  which correspond to the proximal fixation apertures  25   a   1 ,  25   a   2  to mark or identify the location of the internal apertures when the rod  26  is in a desired position in the patient. This allows the physician to be able to insert the proximal fixation members  35   a ,  35   b  in the proper location, aligned with the proximal apertures on the rod  26  held inside the patient.  
         [0061]     As shown, the visual indicia  153 ,  155  is preferably provided as laterally extending drill guides  153 ,  155  which act to support a drill as it enters the patient and allows the drill to be inserted therein and guided to the desired location to provide bores into the bone on opposing sides of the rod  26  that are aligned with the rod proximal fixation apertures  25   a   1 ,  25   a   2 .  
         [0062]     Referring to  FIG. 12 , generally described, to position the intramedullary fixation rod  26  into the patient, an incision is made, such as a sigmoid or longitudinal incision over the radial styloid region of the patient&#39;s arm (adjacent to the base of the thumb). As shown in  FIG. 13 , dissection is carried down to the interval between the first and second dorsal compartments. Care should be taken so as not to injure the branches of the dorsal radial nerve. A small area of exposed bone is present between the first and second compartments (typically covered only by periosteum). As shown in  FIGS. 14 and 15 A, a small bone window  16  is preferably formed or made into the radius in his area. It may be appropriate to elevate the sheaths of the first and second dorsal compartments to facilitate adequate exposure for the bone window  16 . Although shown as a substantially rectangular bone window, other shapes may also be used to provide access to the fracture region.  
         [0063]     As shown in  FIG. 15   w , a finder, sound, or broach-like device  175  can be used prior to inserting the fixation rod  26  into the patient. The device  175  is preferably semi-flexible to follow the contour of the canal in the radius. The device  175  can be inserted through the bone window  16  and about the fracture region and used to determine the size and length of the intramedullary canal and/or to open the canal to a size suitable for receiving the fixation rod  26 . The sounds are available in length-and width calibrated sizes to help determine a size and length suitable for the fixation rod  26  according to the particular patient&#39;s intramedullary canal structure. As such, the device  175  can bore out or ream and/or define a desired entry and insertion passageway for the device  25 ,  25 ′,  25 ″ in advance of an actual installation into the patient. A fluoroscopic evaluation technique can be used to visualize the insertion of the device  175  and can help determine if the canal needs to be enlarged with a reamer or if a insertion path needs to be formed or shaped.  
         [0064]     After the appropriate size and length fixation rod  26  is selected, the rod can be attached to an insertion guide device  150 ,  150 ′.  FIG. 10  illustrates one embodiment of a guide  150 . As shown, an applicator/handle or driver  150  is attached to the rod  26  into the distal aperture  30   a ). The handle or driver  150  then allows the physician to insert and guide the rod  26  into the desired location in the medullary canal in the radius. Once the head  26   h  of the rod  26  is positioned below the articular joint surface, in its desired location in the distal radius, the proximal fixation members  35  ( 35   a ,  35   b ) are ready for insertion. Preferably, a small incision (or two) is made at the proximal site of the radius. A drill or driver is inserted into the locator or drill guide holder  152  to align the entry of the proximal fixation member about the proximal aperture  25  and then force the threaded proximal fixation member(s)  35  ( 35   a ,  35   b ) through the bone on the first (dorsal) side of the shaft of the radius, through the rod aperture  25   a   1 , ( 25   a   2 ) and into the bone on the opposing (volar) side of the radial shaft. Preferably, the proximal fixation member  35  ( 35   a ,  35   b ) extends through both sides of the bone. Next, the guide  150  shown in  FIG. 10  is removed and the distal fixation member  30  is then inserted into the rod  26  through the distal aperture  30   a  and attached to the distal radius ( FIG. 4 ). Preferably, the distal fixation member  30  is inserted into the radius at the fracture site or at an exposed site (created by removing a portion of the bone) to allow the head  30   h  ( FIG. 3A ) of the distal fixation member  30  to be inserted into the rod  26  such that it rests directly against the body of the rod  26  (either protruding, flush recessed therewith) and extends into the distal fracture fragment  18 .  
         [0065]      FIGS. 16 and 17  illustrate an additional embodiment of an insertion guide  150 ′. In this embodiment, the device  150 ′ includes a rod driver  250  and an interlocking screw attachment guide  151 ′. Once the proper rod size is identified, the rod  26  is attached to the rod driver  250 . The rod driver  250  is attached to the fixation rod  26  via the distal aperture in the head of the rod  26  and an associated attachment member (shown as a screw  30   a ) and the interlocking screw attachment guide  151 ′ is attached to the rod driver  250 . As for the other guide embodiment described above, the interlocking screw attachment guide  151 ′ provides a screw guide alignment means such as screw or pin portals  153 ,  155  to facilitate proper orientation and location of the proximal screws or pins into the patient and into the shaft  25  of the fixation rod  26 . Thus, in this embodiment, the span of the screw attachment guide  151 ′ is configured to provide the proper alignment position relative to the rod driver  250 .  
         [0066]     As shown in  FIGS. 18 and 19 , the rod driver  250  of the insertion guide  150 ′ is used to direct the rod  26  into the intramedullary canal of the patient. The rod driver  250  allows a physician to direct the fixation rod  26  into the radius through the bone window  16 . The position of the rod and the reduction of the fracture can be verified by a fluoroscopy unit. Once the rod  26  is in position, a small incision can be made so that the proximal attachment guides  153 ,  155  can be inserted therein. Traction may be appropriate to reduce the fracture at this time. The proximal attachment members  35   a ,  35   b  can then be inserted into the radius after the region has been drilled and/or tapped. Again, the proper positioning of the proximal attachment members  35   a ,  35   b , can be verified by the fluoroscopy unit. The interlocking screw attachment guide  151 ′ an then be removed from the patient and the rod driver  250 . The rod driver  250  can be detached from the fixation rod  26  and the distal fixation member  30  can be inserted into the distal fragment and the fixation rod  26  as shown in  FIG. 20 .  
         [0067]     Routine closure is performed on the incision sites and then, preferably, a long arm cast is applied to the patient. The typical healing process is about six weeks, during which time it is preferred that the treatment area be protected from undue stress and activity.  
         [0068]     A rod according to the present invention can be formed from a number of suitable biocompatible materials including titanium, stainless steel, and cobalt chrome. Because the radius is not a weight bearing extremity strength is not as important in this type of fixation rod as it might be in other fixation rod applications.  
         [0069]     Surface coatings may also be used as appropriate. For example, as the device  25 ,  25 ′,  25 ″ chronically resides in the body, surface or other treatments may also be applied to, or integrated into, the rod  26  and/or the fixation members  30 ,  35  to achieve one or more of increased lubricity, low coefficient of friction (each for easier insertion) as well as increased tissue biocompatibility such as resistance to microbial growth and/or configured to reduce the incidence of inflammation or infection during healing. In one embodiment, the rod  26  comprises a material, at least on its exposed surfaces, which can inhibit the growth of undesirable microbial organisms. Preferably, the rod is coated with a biocompatible antimicrobial solution or coating which can inhibit the growth of bacteria, yeast, mold, and fungus. One suitable material may be the antimicrobial silver zeolite based product available from HealthShield Technologies LLC of Wakefield, Mass. Another alternative is a Photolink® Infection Resistance antimicrobial coating or a hemocompatible coating from SurModics, Inc. of Eden Prairie, MN. The coating may also include other bioactive ingredients (with or without the antimicrobial coating), such as antibiotics, and the like. One product is identified as LubiLAST™ lubricious coatings from AST of Billerica, Mass.  
         [0070]     In addition to, or alternatively, a rod according to the present invention can be configured with a biocompatible lubricant or low-friction material to help reduce any discomfort associated with the insertion of the device into the body. Coatings which may be appropriate include coatings which promote lubricity, and wettability. For example, a hydrophilic coating which is applied as a thin (on the order of about 0.5-50 microns thick) layer which is chemically bonded with UV light over the external surface of the rod  26 . One such product is a hydrophilic polymer identified as Hydrolene® available from SurModics, Inc., of Eden Prairie, MN. Other similar products are also available from the same source. Still further, the rod  26  can be configured not only to provide the lubricious coating but to also included bioactive ingredients configured to provide sustained release of antibiotics, anti microbial, and anti-restenosis agents, identified as LubrilLast™ from AST as noted above.  
         [0071]      FIG. 11  illustrates the steps of a method for treating a fracture in the radius of a patient according to one embodiment of the present invention. An elongated axially extending rod is inserted into the intramedullary canal of the patient (Block,  210 ). Proximal fixation members are then secured to the rod to hold the rod in the intramedullary canal attached to the proximately located bone in the radius shaft (Block  220 ). A distal fixation member is inserted into a distal portion of the rod such that it extends substantially medially or transversely across a distal portion of the radius (Block  230 ). A bone window may be formed into the radius to define an entry point for the rod (typically the window is formed into a small area of exposed bone which is present between the first and second compartments and covered only by periosteum) in the styloid region adjacent the two bone fragments.  
         [0072]     The internal intramedullary radius fixation devices and associated treatment methods of the instant invention can provide improved or alternative treatment options over those conventionally available. The devices and methods of the instant invention may inhibit the collapse in the skeletal structure along the fracture fragment region and may be useful for the osteoporotic patient. The devices of the instant invention can also provide increased structural integrity and/or strength when in position in the distal radius fracture fragment.  
         [0073]     The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. Although a few exemplary embodiments of this invention have been described, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the claims. In the claims, means-plus-function clauses, if used, are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Therefore, it is to be understood that the foregoing is illustrative of the present invention and is not to be construed as limited to the specific embodiments disclosed, and that modifications to the disclosed embodiments, as well as other embodiments, are intended to be included within the scope of the appended claims. The invention is defined by the following claims, with equivalents of the claims to be included therein.

Technology Classification (CPC): 0