Abstract:
An intramedullary implant system, and method for placement within a bone system are provided by the invention. The implant includes a body with at least one pair of beams arranged about a longitudinal axis of the body. The beams are each fixed to the body and each have an end. The end of one of the beams of a pair is releasably coupled to the other beam of the pair by a k-wire from one end of which extends a flexible tail. The beams are each deflectable between (i) a coupled and biased position for insertion of the beams into a respective bone, and (ii) an uncoupled position for gripping bone. The beams of each pair in the uncoupled position being arranged so as to compressively engage the bone.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part application of co-pending U.S. application Ser. No. 14/179,172, filed on Feb. 12, 2014, the entirety of which is incorporated by reference herein. 
    
    
     FIELD OF DISCLOSURE 
     The disclosed device, system, and method relate to implants and, more particularly to implants for installation in an appendage for treating a variety of skeletal maladies including hammer toe. 
     BACKGROUND OF THE INVENTION 
     Hammer toe is a deformity of the toe that affects the alignment of the bones adjacent to the proximal interphalangeal (PIP) joint. Hammer toe can cause pain and can lead to difficulty in walking or wearing shoes. A hammer toe can often result in an open sore or wound on the foot. In some instances, surgery may be required to correct the deformity by fusing one or both of the PIP and distal interphalangeal (DIP) joints. 
     The most common corrective surgery includes the placement of a pin or rod in the distal, middle, and proximal phalanxes of the foot to fuse the PIP and DIP joints. The pin or rod is cut at the tip of the toe, externally of the body. A plastic or polymeric ball is placed over the exposed end of the rod, which remains in the foot of the patient until the PIP and/or DIP joints are fused in approximately 6 to 12 weeks. This conventional treatment has several drawbacks such as preventing the patient from wearing closed toe shoes while the rod or pin is in place, and the plastic or polymeric ball may snag a bed sheet or other object due to it extending from the tip of the toe resulting in substantial pain for the patient. 
     Another conventional implant includes a pair of threaded members that are disposed within adjacent bones of a patient&#39;s foot. The implants are then coupled to one another through male-female connection mechanism, which is difficult to install in situ and has a tendency to separate. 
     Yet another conventional implant has a body including an oval head and a pair of feet, which are initially compressed. The implant is formed from nitinol and is refrigerated until it is ready to be installed. The head and feet of the implant expand due to the rising temperature of the implant to provide an outward force on the surrounding bone when installed. However, the temperature sensitive material may result in the implant deploying or expanding prior to being installed, which requires a new implant to be used. 
     Accordingly, an improved intramedullary implant for treating hammer toe and other maladies of the skeletal system is desirable that provides active compression across a joint and maintains compression thereafter so as to greatly increase the fusion rate. The implant should be insertable with minimal disruption to the DIP joint while optimizing compression and fixation at the PIP joint. Such an improved implant could find efficacy in Hammertoe surgery. 
     SUMMARY OF THE INVENTION 
     An intramedullary implant system is provided that includes a body from each opposite end of which project a pair of beams arranged about a longitudinal axis of the body. The beams are each fixed to the body and each has a coupling latch with a bore so that the coupling latch of each of the beams of a pair may be releasably coupled to the other beam of the pair of beams by a removable coupling rod. A flexible tail projects from one end of the removable coupling rod projects outwardly. Each of the pair of beams is movable between (i) a coupled and biased position wherein the coupling rod is located in each bore of each latch so that the implant may be inserted into a respective bone with at least a portion of the flexible tail protruding from the implant, and (ii) an uncoupled position for internally gripping the respective bone. The beams of each pair in the uncoupled position diverge away from the longitudinal axis of the body wherein an outer surface of each beam is adapted to form a compressive engagement with the respective bone when disposed in the uncoupled position. 
     In another embodiment of a intramedullary implant system, a body has an end from which project a pair of beams arranged about a longitudinal axis of the body. The beams are each fixed to the body with the end of one of the beams being releasably coupled to the other beam of the pair by a removable coupling rod. A flexible tail projects from one end of the coupling rod. The beams are each deflectable between (i) a coupled and biased position for insertion of the beams into a respective bone and with at least a portion of the flexible tail positioned within a bone, and (ii) an uncoupled position for gripping the respective bone, the pair of beams in the uncoupled position being arranged so as to form a compressive engagement with the respective bone. 
     In a further embodiment of an intramedullary implant system a first k-wire is provided from one end of which extends a flexible tail. A body is provided from opposite ends of which project at least one pair of beams arranged about a longitudinal axis of the body. The beams are each fixed to the body and each have a coupling latch with a bore so that the coupling latch of each of the beams of a pair may be releasably coupled to the other beam of the pair of beams by the k-wire such that each of the pair of beams is movable between (i) a coupled and biased position wherein the k-wire is located in each bore of each latch so that the implant may be inserted into a respective bone and (ii) an uncoupled position wherein the k-wire is removed from each bore of each latch so that the beams of each pair diverge away from the longitudinal axis of the body wherein an outer surface of each beam is adapted to form a compressive engagement with the respective bone when disposed in the uncoupled position. 
     A method for implanting a device within a bone is provided that includes opening and debriding a target bone system. A canal is formed through the target bone system, and a k-wire is provided that has a flexible tail extending from one end. An implant is also provided that includes a body from opposite ends of which project at least one pair of beams arranged about a longitudinal axis of the body wherein the body defines a passageway along the longitudinal axis. The beams are each fixed to the body and each has a coupling latch with a bore. The latch of each beam is releasably coupled to one another by inserting the k-wire into the latch bores thereby biasing the beams. The implant and k-wire are inserted into the canal along with the flexible tail, often protruding from the patient&#39;s body. By pulling upon the flexible tail so as to decouple and remove the k-wire from the latches, the beams are thereby decoupled and released from their biased state so that a portion of each beam engages the surface of the surrounding bone that defines the canal. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features and advantages of the invention will be more fully disclosed in, or rendered obvious by the following detailed description of preferred embodiments of the invention, which are to be considered together with the accompanying drawings wherein like numbers refer to like parts and further wherein: 
         FIG. 1  is a perspective view of an intramedullary implant formed in accordance with one embodiment of the invention; 
         FIG. 2  is a top plan view of the implant shown in  FIG. 1 ; 
         FIG. 3  is a top plan view of the implant shown in  FIGS. 1 and 2 , and with a K-wire coupled to the implant; 
         FIG. 4  is a top plan view, partially in phantom, illustrating the change in length of the beams as a result of decoupled bending; 
         FIG. 5  is a perspective view of the distal, middle, and proximal phalanxes with a K-wire installed, and with the soft tissues removed for clarity of illustration; 
         FIG. 5A  is a further perspective view of the distal, middle, and proximal phalanxes without a K-wire installed, and with the soft tissues removed for clarity of illustration; 
         FIG. 6  is a side view of the distal, middle, and proximal phalanxes shown in  FIGS. 5 and 5A ; 
         FIG. 7  is a side view of the distal, middle, and proximal phalanxes with an implant formed in accordance with one embodiment of the invention installed in the proximal end of a middle phalanx, and with the soft tissues removed for clarity of illustration; 
         FIG. 8  is a top plan view showing an implant fully installed between the proximal and middle phalanxes, just prior to removal of the k-wire; 
         FIG. 9  is a top plan view showing an implant fully installed between the proximal and middle phalanxes, with the K-wire removed and decoupled from the proximal and distal pair of beams, and illustrating an implant fully installed within the bones; 
         FIG. 6A  is a top plan view of a distal and middle phalanx showing initial insertion of an implant device and system in accordance with an alternative method of installation; 
         FIG. 7A  is a top plan view, similar to  FIG. 6A , showing further progress of the implant system through a canal broached within the bones; 
         FIG. 7B  is a side view, partially in phantom showing progress of the implant system, including a k-wire with a flexible tail, through a canal broached within the bones; 
         FIG. 8A  is a top plan view, similar to  FIGS. 6A and 7A , showing a K-wire partially removed and decoupled from a distal pair of beams, and illustrating the compressive engagement of the beams against the internal surfaces of the bone; 
         FIG. 8B  is a top plan view, similar to  FIG. 7B , showing an implant coupled by a K-wire with a flexible tail prior to removal and decoupling from a distal pair of beams; 
         FIG. 9A  is a top plan view, similar to  FIGS. 6A, 7A, and 8A , showing the implant fully installed with the K-wire removed and decoupled from a proximal pair of beams, and illustrating an implant fully installed within the bones; 
         FIG. 9B  is a perspective view of an implant formed in accordance with the invention, showing an alternative K-wire having a flexible tail installed and coupling the beams of the implant; 
         FIG. 9C  is a side elevational view of the implant and k-wire shown in  FIG. 9B , with the implant shown in cross-section for clarity of illustration perspective view of an implant formed in accordance with the invention, showing an alternative K-wire having a flexible tail installed and coupling the beams of the implant; 
         FIG. 9D  is a top plan view, similar to  FIGS. 7B and 8B , showing a K-wire with a flexible tail partially removed and decoupled from a distal pair of beams, and illustrating the compressive engagement of the beams against the internal surfaces of the bone; 
         FIG. 9E  is a perspective view, partially in phantom, of a human foot located within a shoe and illustrating one possible arrangement of a flexible tail and second k-wire after implantation of an implant formed in accordance with on embodiment of the invention; 
         FIG. 10  is a perspective view of the implant shown in  FIGS. 11 and 12  with the K-wire reinstalled through central canal to stabilize neighboring joints (MTP); 
         FIG. 11  is a further perspective view of the implant shown in  FIG. 12 , with a K-wire removed; 
         FIG. 12  is a perspective view of an alternative embodiment of implant formed in accordance with the invention; 
         FIG. 13  is a top plan view of a further alternative embodiment of the invention, showing a K-wire partially in phantom, installed and coupled to a single pair of beams; 
         FIG. 14  is a top plan view of the implant shown in  FIG. 13 , but with the K-wire removed and decoupled from the beams; 
         FIG. 15  is a top plan view, similar to  FIG. 14 , showing a K-wire prior to coupling with the implant; 
         FIG. 16  is a bottom plan view of the implant shown in  FIG. 15 , but from the reverse side so as to reveal grooves or channels formed in the implant for receiving a coupling K-wire; 
         FIG. 17  is a top plan view, partially in phantom, showing a K-wire coupled with the implant of  FIGS. 15-16 ; 
         FIG. 18  is a further embodiment of implant formed in accordance with the invention; 
         FIG. 19  is a cross-sectional view, similar to  FIG. 18 , but showing a K-wire coupled to the beams of the implant; 
         FIG. 20  is an end view of a further embodiment of implant formed in accordance with the invention; 
         FIG. 21  is a side elevational view of the further embodiment shown in  FIG. 20 ; 
         FIG. 22  is a cross-sectional view, taken along lines  22 - 22  in  FIG. 21 ; 
         FIG. 23  is a perspective view of a further embodiment of the invention showing an implant having a curved cross-sectional profile; 
         FIG. 24  is a side elevational view of an angled implant embodiment of the invention; 
         FIG. 25  is a top plan view of the angled embodiment of the invention shown in  FIG. 24 ; 
         FIG. 26  is an end on, perspective view of the embodiment of implant shown in  FIGS. 24 and 25 ; 
         FIG. 27  is a cross-sectional view taken along lines  27 - 27  of the angled embodiment shown in  FIGS. 24-26 ; 
         FIG. 28  is a top plan view of yet a further embodiment of implant showing a pair of beams disposed diagonally on the body of the implant; 
         FIG. 29  is top view similar to  FIG. 28 , showing the implant coupled to a K-wire in accordance with invention; 
         FIG. 30  is a top view of yet a further embodiment of implant showing a pair of beams disposed on the same side of the body of the implant; 
         FIG. 31  is a top view similar to  FIG. 30 , showing the implant coupled to a K-wire in accordance with invention; 
         FIG. 32  is a perspective view of an embodiment formed in accordance with the invention showing a single pair of beams coupled to a K-wire; 
         FIG. 33  is a cross-sectional view, taken along line  33 - 33  in  FIG. 32 ; 
         FIG. 34  is a perspective exploded view of the alternative embodiment implant of  FIGS. 32 and 33 , showing a therapeutic device prior to interconnection with the implant; 
         FIG. 35  is a perspective view of the implant and therapeutic device shown in  FIG. 34 , after interconnection; 
         FIG. 36  is a cross-sectional view of the implant and therapeutic device interconnected in  FIG. 35 ; 
         FIG. 37  is a perspective view, similar to  FIG. 34 , showing a therapeutic device in the form of a bone anchor just prior to interconnection with the implant; 
         FIG. 38  is a perspective view, similar to  FIG. 35 , showing bone anchor of  FIG. 37  interconnected with the implant; 
         FIG. 39  is a cross-section view, similar to  FIG. 36 , but showing a bone anchor of  FIGS. 37 and 38  interconnected with an implant formed in accordance with the invention; 
         FIG. 40  is an exploded perspective view of an implant similar to that shown in  FIGS. 34 and 37 , showing a suture anchor just prior to interconnection with the implant; 
         FIG. 41  is a perspective view similar to  FIG. 40  but showing the suture anchor installed on the implant; 
         FIG. 42  is a cross-sectional view, taken along line  42 - 42  in  FIG. 41 , showing the suture anchor installed on the implant with suture threaded through a conduit defined to the middle of the body of the implant and also showing a K-wire coupled to the single pair of beams; 
         FIG. 43  is a cross-sectional view similar to  FIG. 42 , with the K-wire decoupled from the single pair of beams; 
         FIG. 44  is a perspective view of a further alternative embodiment of the invention showing a bone screw interconnected with the implant of the invention; 
         FIG. 45  is a cross-sectional view, taken along line  45 - 45  in  FIG. 44 , and also showing a K-wire coupled to a single pair of beams; 
         FIG. 46  is a cross-sectional view similar to  FIG. 45 , but showing the single pair of beams after decoupling from the K-wire; 
         FIG. 47  is another embodiment of implant similar to that shown in  FIGS. 34, 37, 40, and 44 , showing a cannulated bone screw installed in the implant with a K-wire located within the cannulated bone screw and coupled to the single pair of beams; 
         FIG. 48  is a cross-sectional view, taken along line  48 - 48  in  FIG. 47 ; and 
         FIG. 49  is a cross-sectional view similar to  FIG. 48  but with the K-wire removed from the cannulated bone screw and decoupled from the single pair of beams. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     This description of preferred embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description. The drawing figures are not necessarily to scale and certain features of the invention may be shown exaggerated in scale or in somewhat schematic form in the interest of clarity and conciseness. In the description, relative terms such as “horizontal,” “vertical,” “up,” “down,” “top,” and “bottom” as well as derivatives thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing figure under discussion. These relative terms are for convenience of description and normally are not intended to require a particular orientation. Terms including “inwardly” versus “outwardly,” “longitudinal” versus “lateral,” and the like are to be interpreted relative to one another or relative to an axis of elongation, or an axis or center of rotation, as appropriate. Terms concerning attachments and the like, such as “coupled” and “coupling” refer to a relationship wherein structures are secured or attached to one another either directly or indirectly, temporarily or permanently, through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. The term “operatively coupled” is such an attachment or connection that allows the pertinent structures to operate as intended by virtue of that relationship. 
     Referring to  FIGS. 1-4 , an implant  2  is provided that includes a cannulated body  4 , a distal pair of cantilevered beams  6 , and a proximal pair of cantilevered beams  8 . More particularly, cannulated body  4  often comprises an elongate bar having a distal end  14  and a proximal end  15 . A through-bore  18  is often defined centrally through the bar along longitudinal axis  17  so as to define openings at distal end  14  and proximal end  15 . 
     Distal pair of beams  6  comprise a superior beam  24  and an inferior beam  26  arranged in spaced confronting relation to one another at distal end  14  of cannulated body  4 . In many of the embodiments of the invention, pairs of beams will be arranged symmetrically about longitudinal axis  17  of body  4 , often so as to be bisected by the axis. Superior beam  24  is fixed to distal end  14  of cannulated body  4 , and in some embodiments, is formed integral with cannulated body  4 . One or more barbs  30   a  are located on an outer surface  31  of superior beam  24 , often oriented transversely across outer surface  31 . A latch-plate  34  extends inwardly, toward inferior beam  26 , from a free end of superior beam  24 . A bore  36   a  is defined through latch-plate  34 . Inferior beam  26  is fixed to distal end  14  of cannulated body  4 , and in some embodiments, is formed integral with cannulated body  4 . One or more barbs  30   b  are located on a distal outer surface  32  of inferior beam  26 , often oriented transversely across outer surface  32 . A latch-plate  38  extends inwardly, toward superior beam  24  and latch-plate  34 , from a free end of inferior beam  26 . A bore  36   b  is defined through latch-plate  38 . 
     Distal pair of beams  6  are cantilevered to cannulated body  4  at distal end  14 , i.e., supported or clamped at one end and capable of storing elastic energy when loaded or pre-loaded at the other end or along their length. When distal pair of beams  6  are loaded during normal use, they each deflect inwardly, toward one another. Advantageously, superior beam  24  is greater in length than inferior beam  26  so that, when deflected to a optimally biased state, i.e., the beams are deflected so that a desirable amount of elastic energy is stored, with latch-plate  34  is located in overlapping adjacent relation to latch-plate  38  with bore  36   a  and bore  36   b  overlapping and communicating relation to one another ( FIGS. 3-4 ). As a result, while distal pair of beams  6  are loaded bores  36   a  and  36   b  will often be arranged in substantially coaxial relation to the open end of through-bore  18  at distal end  14  of cannulated body  4 . 
     Proximal pair of beams  8  comprise a superior beam  44  and an inferior beam  46  arranged in spaced confronting relation to one another at proximal end  15  of cannulated body  4 . Superior beam  44  is fixed to proximal end  15  of cannulated body  4 , and in some embodiments, is formed integral with cannulated body  4 . One or more barbs  50   a  are located on an outer surface  51  of superior beam  44 , often oriented transversely across outer surface  51 . A latch-plate  54  extends inwardly, toward inferior beam  46 , from a free end of superior beam  44 . A bore  56   b  is defined through latch-plate  54 . Inferior beam  46  is fixed to proximal end  15  of cannulated body  4 , and in some embodiments, is formed integral with cannulated body  4 . One or more barbs  50   b  are located on a distal outer surface  52  of inferior beam  46 , often oriented transversely across outer surface  52 . A latch-plate  58  extends inwardly, toward superior beam  44  and latch-plate  54 , from a free end of inferior beam  46 . A bore  56   a  is defined through latch-plate  58 . 
     As with distal pair of beams  6 , proximal pair of beams  8  are also cantilevered to cannulated body  4 , but at proximal end  15 , i.e., supported or clamped at one end and capable of storing elastic energy when loaded or pre-loaded at the other end or along their length. When proximal pair of beams  8  are loaded during normal use, they each deflect inwardly, toward one another. Advantageously, superior beam  44  is greater in length than inferior beam  46  so that, when deflected to a optimally biased state, latch-plate  58  is located adjacent to latch-plate  54  with bore  56   a  and bore  56   b  overlapping one another. As a result, bores  56   a  and  56   b  often will be arranged in substantially coaxial relation to the open end of through-bore  18  at proximal end  15  of cannulated body  4 . 
     When cantilevered distal pair of beams  6  and proximal pair of beams  8  move into their respective second partially biased state, they undergo a so-called “large deflection” in accordance with classical beam theory. In other words, the moment arm of each of superior beam  24 , 44  and inferior beam  26 , 46  changes as the loaded ends of the beams deflect inwardly toward one another. Referring to  FIG. 4 , it will be understood by those skilled in the art that when distal pair of beams  6  and proximal pair of beams  8  are arranged in their optimally biased state, the distance β measured between their outer most barbs is at a maximum, but when cantilevered distal pair of beams  6  and proximal pair of beams  8  are allowed to move into their respective second partially biased state, the distance θ measured between the outer most barbs is at a minimum. Thus, there is a differential in the length of the beams, δ, between their optimally biased state and their second partially biased state. This difference δ represents an available amount of compressive engagement or “bite” of the barbs into the bone that defines broached canal D. 
     Implant  2  may be manufactured from conventional implant metal, such as stainless steel or titanium. In several preferred embodiments, however, the implants are manufactured out of shape memory materials (SMA) or alloys such as nickel titanium to enhance fixation. One example of such an alloy is Nitinol sold by Memry Corporation of Menlo Park, Calif. The implants are preferably made of nitinol, a biocompatible, shape memory metal alloy of titanium and nickel. The metal&#39;s properties at the higher temperature (austenite phase) are similar to those of titanium. The temperature at which the implants will undergo the shape transformation can be controlled by the manufacturing process and the selection of the appropriate alloy composition. Nitinol has a very low corrosion rate and has been used in a variety of medical implants, e.g., orthodontic appliances, stents, suture anchors, etc. Implant studies in animals have shown minimal elevations of nickel in the tissues in contact with the metal; the levels of titanium are comparable to the lowest levels found in tissues near titanium hip prostheses. In most embodiments of the invention, the SMA is selected to have a temperature transformation range such that the implant undergoes a transition from austenite to stress-induced martensite under the influence of deformation forces. Thus, when the distal and proximal beams of implant  2  are deflected inwardly, toward one another and then released, they are already at a temperature such that they automatically attempt to reform to their original shape. 
     Referring to  FIGS. 5-9A , implant  2  is prepared for use in corrective surgery at the distal B, middle A, and proximal C phalanxes of the foot, as follows. Distal pair of beams  6  are loaded so that they each deflect inwardly, toward one another until latch-plate  38  is located adjacent to latch-plate  34  with bore  36   a  and bore  36   b  overlapping one another. Likewise, proximal pair of beams  8  are also loaded so that they each deflect inwardly, toward one another until latch-plate  58  is located adjacent to latch-plate  54  with bore  56   a  and bore  56   b  overlapping one another. Once in this arrangement, a coupling rod, such as k-wire  60 , is inserted through bores  56   a ,  56   b , through-bore  18 , and bores  36   a  bore  36   b , thereby coupling distal pair of beams  6  and proximal pair of beams  8  in their respective optimally biased state. In some embodiments, k-wire  60  includes a proximal portion  63  that has a smaller diameter than the distal portion of the k-wire thereby defining a shoulder  67  at the transition  69  between diameters. Shoulder  67  is often sized so as to engage the outer surface of latch-plate  54  and thereby prevent k-wire  60  from further travel into implant  2  beyond transition  69 . In another embodiment shown in  FIG. 9B , a k-wire  61  comprises a flexible tail  62  that is terminated by a second k-wire  64 . Flexible tail  62  may be fashioned from woven, non-woven, knitted, braided or crocheted materials, any of which can included but not be limited to standard surgical sutures, polymer or fiberous cords, metal wire or tape, or the like, and may be formed from a single multiple strands of metals, polymers, or other bio compatible materials. Often, flexible tail  62  comprises a metal braid or cable. K-wire  61  may have a circular, oval or flattened cross-sectional profile similar to that of K-wire  60   b  ( FIGS. 20-23 ). 
     Implant  2  is used in systems and methods for corrective surgery at the distal B, middle A, and proximal C phalanxes of the foot or elsewhere in bones of the human or animal body, as follows. The PIP joint is first opened and debrided and an initial k-wire  75  ( FIG. 5 ) is inserted through the axis of the middle phalanx A and out the distal end of the toe. Initial k-wire  75  is then removed distally from the distal tip of the toe ( FIGS. 5A and 6 ). Using a broach or similar instrument (not shown) a canal D is defined through distal and proximal portions of the PIP joint. Canal D extends for a distance into middle phalanx A along the path defined previously by k-wire  75  such that a counter-bore shoulder  71  is defined at the transition between the diameters of canal D and the passageway formed by the prior insertion of k-wire  75 . Shoulder  71  is often sized so as to engage the outer surface of a latch-plate  54  or  34  and thereby prevent implant  2  from further distal travel into middle phalanx A. 
     Once the surgical site has been prepared in the foregoing manner, an implant  2  that has been coupled to a k-wire  60  or  61  is inserted through broached canal D ( FIGS. 7 and 7B ) such that k-wire  60  travels through middle phalanx A and distal phalanx B with distal end portion  63  projecting outwardly from the end of distal phalanx B. In the alternative, flexible tail  62  travels through middle phalanx A and distal phalanx B with distal end portion  63  projecting outwardly from the end of distal phalanx B. Flexible tail  62  may often be employed to ease implantation. In one embodiment, a cord  62  provides the flexibility that is often needed by the surgeon to position the implant within the patient&#39;s bone, while maintaining tensile strength for removing k-wire  61  from the implant during deployment. In one embodiment, flexible tail  62  and k-wire are left protruding from the patient&#39;s foot F by the surgeon so as to allow the patient to slip on a shoe G or other foot wear ( FIG. 9E ). Traditionally, a rigid k-wire was left protruding from the patient&#39;s toe by the surgeon, when the surgery was completed. This arrangement prevented the patient from wearing shoes which often precluded the patient from returning to work based upon work place safety regulations. 
     With either arrangement, implant  2  travels down the longitudinal axis of middle phalanx A until the constrained distal beams  6  are adjacent shoulder  71  within broached canal D ( FIG. 7 ). Once in position, end portions of distal pair of beams  6  are located adjacent to shoulder  71  within middle phalanx A and proximal pair of beams  8  project outwardly from the open end of canal D at the proximal end of middle phalanx A. Next, the joint is re-aligned and closed by moving the distal and middle phalanxes so that proximal pair of beams  8  is caused to enter the open end of canal D in proximal phalanx C ( FIG. 8 ). In this position, proximal pair of beams  8  are located within canal D in proximal phalanx C and the joint is closed around implant  2 . 
     Once in the foregoing arrangement, k-wire  60  is moved distally ( FIG. 9 ) so as to disengage from latch-plates  54  and  58  of proximal beams  8  thereby decoupling and releasing beams  44  and  46  from their optimally biased state. Alternatively, k-wire  64  is moved distally ( FIGS. 8B and 9C )) thereby pulling flexible tail  62  and k-wire  61  so as to disengage from latch-plates  54  and  58  of proximal beams  8  thereby decoupling and releasing beams  44  and  46  from their optimally biased state. As a result, superior beam  44  and inferior beam  46  spring outwardly, away from one another, until their respective barbs  50   a  and  50   b  engage the surface of the surrounding bone that defines broached canal D. Since superior beam  44  and inferior beam  46  are still biased, i.e., continue to store some elastic energy, but are geometrically shortened by an amount δ. Barbs  50   a  and  50   b  compressively engage the surface of the surrounding bone so as to “bite” into the bone, thus enhancing the retention of implant  2 . It should be noted that the respective shortening of the moment arm of proximal pair of beams  8  applies an active compressive force to articulating surfaces of the PIP joint. K-wire  60  continues to be decoupled and withdrawn from implant  2 , through through-bore  18  of cannulated body  4  until distal end  70  slips past through-bores  36   a ,  36   b  in latch-plates  34  and  38  of distal pair of beams  6  so as to entirely decouple k-wire  60  from implant  2  ( FIG. 9 ). As a consequence, superior beam  24  and inferior beam  26  spring outwardly, away from one another and away from their optimally biased state into a partially biased state in which distal pair of beams  6  engage the surface of the bone that defines broached canal D. Here again, it will be understood by those skilled in the art that as cantilevered distal pair of beams  6  move into their second partially biased state, they will also shorten. This geometric effect applies an active compressive force to the articulating surfaces of the PIP joint while proximal pair of beams  8  maintain cortical fixation on either side of the joint. Advantageously, barbs  30   a  and barbs  30   b  are caused to bite into the bone that defines broached canal D by the outward force of superior beam  24  and inferior beam  26  moving into their partially biased state. The biting of barbs  30   a  and  30   b  into the bone greatly enhances the compressive load exerted by proximal pair of beams  8 . 
     In an alternative embodiment illustrated in  FIGS. 6A-9A , once the surgical site has been prepared as described hereinabove, an implant  2  that has been coupled to a k-wire  60  is inserted through broached canal D ( FIG. 6A ). In this way, implant  2  travels along the longitudinal axis of middle phalanx A until the constrained proximal beams  8  are adjacent the end of broached canal D within proximal phalanx C ( FIG. 7A ). Once in position, k-wire  60  is moved distally ( FIG. 8A ) so as to disengage distal portion  63  from latch-plates  34  and  38  of proximal beams  8  thereby decoupling and releasing beams  24  and  26  from their optimally biased state. As a result, superior beam  24  and inferior beam  26  spring outwardly, away from one another, until their respective barbs  30   a  and  30   b  engage the surface of the surrounding bone that defines broached canal D. Since superior beam  24  and inferior beam  26  are still biased, i.e., continue to store some elastic energy, but are geometrically shortened by an amount δ, barbs  30   a  and  30   b  compressively engage the surface of the surrounding bone so as to “bite” into the bone, thus enhancing the retention of implant  2 . It should be noted that the respective shortening of the moment arm of proximal pair of beams  8  applies an active compressive force to articulating surfaces of the PIP joint while distal pair of beams  6  maintain cortical fixation via barbs  30   a  and  30   b.    
     With proximal pair of beams  8  fully seated within the proximal phalanx C, the joint is compressed axially so as to fully seat proximal pair of beams  8  within broached canal D ( FIG. 8A ). K-wire  60  continues to be decoupled and withdrawn from implant  2 , through through-bore  18  of cannulated body  4  until proximal end  70  slips past through-bores  56   a ,  56   b  in latch-plates  54  and  58  of distal pair of beams  6  so as to entirely decouple k-wire  60  from distal pair of beams  6  ( FIG. 9A ). As a consequence, distal pair of beams  6  spring outwardly, away from one another and away from their optimally biased state into a partially biased state in which distal pair of beams  6  engage surface of the bone that defines broached canal D. Here again, it will be understood by those skilled in the art that as cantilevered distal pair of beams  6  move into their second partially biased state, they will also shorten their length. This geometric effect applies an active compressive force to the articulating surfaces of the PIP joint while distal pair of beams  6  maintain cortical fixation. Advantageously, barbs  50   a  located on an outer surface  51  of superior beam  44  and barbs  50   b  located on outer surface  52  of inferior beam  46  are caused to bite into the bone that defines broached canal D by the outward force of superior beam  44  and inferior beam  46  moving into their partially biased state. The biting of barbs  30   a ,  30   b ,  50   a  and  50   b  into the internal bone surfaces at both sides of the joint, coupled with the geometric shortening of both proximal beams  8  and distal beams  6 , greatly enhances the compressive load exerted across the PIP joint. 
     Numerous changes in the details of the embodiments disclosed herein will be apparent to, and may be made by, persons of ordinary skill in the art having reference to the foregoing description. For example, and referring to  FIGS. 10-12 , implant  82  is provided that includes a body  84 , a distal pair of cantilevered beams  86 , and a proximal pair of cantilevered beams  88 . Unlike cannulated body  4  of implant  2 , body  84  defines an elongate, channel or groove  90  having a distal end  94  and a proximal end  95 . Distal pair of beams  86   a ,  86   b  are arranged in spaced confronting relation to one another at distal end  94  of body  84 . Each beam  86   a ,  86   b  is fixed to distal end  94  and in some embodiments, is formed integral with body  84 . One or more barbs  96  are located on an outer surface of each distal beam  86   a ,  86   b . Open-ended groove  90  extends through an inner portion of body  84 . An open-ended groove  100   a  is defined as a channel through an inner distal portion of distal beam  86   b  ( FIG. 10 ) that is sized so as to slidingly receive a sharpened portion of a k-wire  60   a . Distal pair of beams  86   a ,  86   b  are cantilevered to body  84 , i.e., supported or clamped at one end and capable of storing elastic energy when loaded or pre-loaded at the other end or along their length. When distal pair of beams  86   a ,  86   b  are coupled and loaded during normal use, they each deflect inwardly, toward one another. 
     Proximal pair of beams  88   a ,  88   b  are arranged in spaced confronting relation to one another at proximal end  95  of body  84 . One or more barbs  96  are located on an outer surface of each proximal beam  88   a ,  88   b . A groove  100   b  is defined as a channel through an inner distal portion of proximal beam  88   a  ( FIGS. 10 and 11 ) that is sized so as to slidingly receive a rounded portion of k-wire  60   b . As with distal pair of beams  86   a , 86   b , proximal pair of beams  88   a , 88   b  are also cantilevered to cannulated body  84  but at proximal end  95 , i.e., supported or clamped at one end and capable of storing elastic energy when loaded or pre-loaded at the other end or along their length. When proximal pair of beams  88   a ,  88   b  are and coupled loaded during normal use, they each deflect inwardly, toward one another. 
     Implant  82  is prepared for use in corrective surgery at the distal B, middle A, and proximal C phalanxes of the foot in much the same way as implant  2 . More particularly, distal pair of beams  86   a ,  86   b  are loaded so that they each deflect inwardly, toward one another such that open-ended groove  90  of body  84  and groove  100   a  are arranged in substantially coaxial relation to one another. Likewise, proximal pair of beams  88   a ,  88   b  are also loaded so that they each deflect inwardly, toward one another such that open-ended groove  90  of body  84  and groove  100   b  are arranged in substantially coaxial relation to one another. Once in this arrangement, k-wire  60   a  is inserted through groove  100   a , open-ended groove  90 , and groove  100   b , thereby coupling distal pair of beams  86   a ,  86   b  and proximal pair of beams  88   a ,  88   b  in their respective optimally biased state. 
     As with implant  2 , removal and decoupling of k-wire  60  causes distal pair of beams  86   a ,  86   b  and proximal pair of beams  88   a ,  88   b  to spring outwardly and away from one another thereby shortening their lengths so as to apply an active compressive force to the articulating surfaces of the PIP joint. Advantageously, barbs  96  are caused to bite compressively into the bone that defines the broached canal by the force of distal pair of beams  86   a ,  86   b  and proximal pair of beams  88   a ,  88   b  moving into their partially biased state as a result of the elastic energy that continues to be stored in in each beam. The biting of barbs  96  into the bone greatly enhances the compressive load exerted by implant  82 . When distal pair of beams  86   a ,  86   b  and proximal pair of beams  88   a ,  88   b  spring outwardly and away from one another after the k-wire  60  is fully decoupled, the elongate channel or groove  90  having a distal end  94  and a proximal end  95  is again able to slidingly receive k-wire  60 . The sharpened portion  60   a  of k-wire  60  is, e.g., driven proximally through the tip of the patient&#39;s toe and through distal end  94  and proximal end  95  of groove  90  of implant  82  to achieve temporary stabilization of outlying joints (e.g., the MTP joint). 
     Implants in accordance with the general principles of the invention may be take a variety of configurations. Referring to  FIGS. 13-17 , a proximal beam  86   a  and distal beam  88   b , may be arranged on their respective ends of body  84  with somewhat thinner or variable cross-sections so as to allow for adjustments in spring force to a predetermined level as may be needed for a particular therapy. Referring to  FIGS. 18-19 , it will be understood that implant  2  may incorporate an inferior latch-plate  38   a  or  58   a  located anywhere along the length of its corresponding beam  26 ,  46 . As shown in  FIGS. 20-23 , implant  2  may have any peripheral shape. Often, implant  2  will have a circular or elliptical peripheral shape so as to be better suited for disposition through drilled canal D. It should be noted that with circular or elliptical embodiments of implant  2 , bores  36   a ,  36   b  or  56   a ,  56   b  may be defined with one or more partially flattened walls  110  so as to allow for sufficient wall thickness in latch plate and for engagement with a correspondingly shaped k-wire  60   b . This arrangement allows the surgeon to rotationally orient implant  2  relative to the bone surface that defines broached canal D. As shown in  FIGS. 24 and 27 , an implant  112  may be formed so as to bend at or adjacent to the central portion of body  4   a . In these embodiments, distal pair of beams  6  or proximal pair of beams  8  may be arranged and oriented at an angle relative to body  4   a . A similarly shaped k-wire also comprised of Nitinol to insert through bend  60   c  is coupled and decoupled during use of implant  112  in a manner previously disclosed herein. 
     Turning now to  FIGS. 28-29 , an implant  122  is provided that includes a body  124 , a distal cantilevered beam  126 , and a proximal cantilevered beam  128 . Body  124  defines an through bore  130  and has a distal end  134  and a proximal end  135 . Proximal beam  126  projects longitudinally outwardly from distal end of body  124 , while distal cantilevered beam  128  projects longitudinally outwardly from the proximal end of body  124 . One or more barbs  136  are located on an outer surface of each of distal end  134  and a proximal end  135 . A latch-plate  140  extends inwardly from a free end of proximal cantilevered beam  126  and a second latch-plate  142  extends inwardly from a free end of distal cantilevered beam  128 . A bore  146   a  is defined through latch-plate  140  and a bore  146   b  is defined through latch-plate  142 . Cantilevered beams  124 ,  126  are cantilevered to body  124 , i.e., supported or clamped at one end and capable of storing elastic energy when loaded or pre-loaded at the other end or along their length. When cantilevered beams  124 ,  126  are loaded during normal use, they each deflect inwardly. Advantageously, cantilevered beams  124 ,  126  are arranged so as to be located diagonally from one another relative to body  124 . 
     Implant  122  is prepared for use in corrective surgery at the distal B, middle A, and proximal C phalanxes of the foot in much the same way as implant  2 . More particularly, proximal cantilevered beam  126  and distal cantilevered beam  128  are loaded so that they each deflect inwardly, toward the longitudinal axis of through bore  130  of body  124  so that bore  146   a  of latch-plate  140  and bore  146   b  of latch-plate  142  are arranged in substantially coaxial relation to one another. Once in this arrangement, k-wire  60  is inserted through bore  130 , bore  146   a , and bore  146   b , thereby coupling distal cantilevered beam  126 , and proximal cantilevered beam  128  in their respective optimally biased state. 
     As with other implant embodiments, decoupling of k-wire  60  causes proximal cantilevered beam  126  and distal cantilevered beam  128  to spring outwardly and away from one another and away from the longitudinal axis of through bore  130  of body  124  thereby shortening their lengths so as to apply an active compressive force to the articulating surfaces of the PIP joint. Advantageously, barbs  96  are caused to bite into the bone compressively by the outward force of proximal cantilevered beam  126  and distal cantilevered beam  128  shortening as they move into their respective partially biased state. The biting of barbs  96  into the internal bone surfaces at both sides of the joint, coupled with the geometric shortening of both proximal and distal beams, greatly enhances the compressive load exerted by implant  122  across the joint. Referring to  FIGS. 30 and 31 , it will be understood that an implant  122   a  may be formed having distal cantilevered beam  126   a  and proximal cantilevered beam  128   a  that are arranged on the same side of body  124  rather than diagonally as in implant  122 . 
     Referring to  FIGS. 32-36 , implant  150  is provided that includes a body  154  and a single pair of cantilevered beams  156  and a mating structure suitable for joining implant  150  to a therapeutic device  157  via interconnection with blind bores  151   a  and  151   b  defined in body  154 . More particularly, single pair of cantilevered beams  156  comprise a superior beam  160  and an inferior beam  162  arranged in spaced confronting relation to one another at an end of body  154 . Superior beam  160  is fixed to an end of body  154 , and in some embodiments, is formed integral therewith. One or more barbs  96  are located on an outer surface of superior beam  160 , often oriented transversely across the outer surface. A latch-plate  164  extends inwardly, toward inferior beam  162 , from a free end of superior beam  160 . A bore  166  is defined through latch-plate  164 . Inferior beam  162  is fixed to an end of body  154 , and in some embodiments, is formed integral therewith. One or more barbs  96  are located on an outer surface of inferior beam  162 , often oriented transversely across the outer surface. A latch-plate  168  extends inwardly, toward superior beam  160  and latch-plate  164 , from a free end of inferior beam  162 . A bore  170  is defined through latch-plate  168 . Cantilevered beams  160 ,  162  are cantilevered to body  154 , i.e., supported or clamped at one end and capable of storing elastic energy when loaded or pre-loaded at the other end or along their length. When cantilevered beams  160 ,  162  are coupled and preloaded during normal use, they each deflect inwardly. 
     Implant  150  is prepared for use in surgery at a variety of orthopedic locations throughout a patient in much the same way as implant  2 . More particularly, single pair of beams  160 ,  162  are loaded so that they each deflect inwardly, toward one another such that bore  166 , bore  170 , and blind bore  151   b  are arranged in substantially coaxial relation to one another. Once in this arrangement, k-wire  60  is inserted through bore  166 , bore  170 , and blind bore  151   b , thereby coupling single pair of beams  160 ,  162  in their respective optimally biased state. As with implant  2 , decoupling of k-wire  60  causes single pair of beams  160 ,  162  to spring outwardly and away from one another thereby shortening their lengths so as to apply an active compressive force to the articulating surfaces of the PIP joint. Advantageously, barbs  96  are caused to bite into the bone compressively by the outward force of pair of beams  160 ,  162  shortening as they move into their respective partially biased state. The biting of barbs  96  into the bone greatly enhances the compressive load exerted by implant  150 . 
     Implants in accordance with the general principles of the foregoing embodiment of the invention may be take a variety of configurations. Referring to  FIGS. 37-39 , a tapered and ribbed anchor  173  may be coupled to body  154  via a threaded engagement between a post  175  and threaded bore  151   a . As shown in  FIGS. 40-43 , a suture anchor  178  may be assembled to body  154  in a similar manner to that of tapered and ribbed anchor  173 . Bores  151   a  and  151   b  may be modified so as to communicate, via conduit  181  ( FIGS. 40-43 ) thereby allowing suture  180  to exit implant  150  near to single pair of beams  160 ,  162 . Often, implant  150  will have a circular or elliptical peripheral shape so as to be better suited for disposition through broached canal D. As shown in  FIGS. 44 and 49 , implant  150  may be formed so as receive a threaded screw  200  or cannulated screw  210 . 
     Although the invention has been described in terms of exemplary embodiments, it is not limited thereto. Rather, the appended claims should be construed broadly, to include other variants and embodiments of the invention, which may be made by those skilled in the art without departing from the scope and range of equivalents of the invention.