BONE IMPLANT WITH MEANS FOR MULTI-DIRECTIONAL FORCE
BACKGROUND OF THE INVENTION
Field, of Invention
[0001] The present invention is in the technical field of medical devices. More particularly, the present invention is in the technical field of bone fixation or arthrodesis or deformity correction. The invention relates to a fixation system for bones of all types. Such systems are used in osteosynthesis (bone fusion), wherein the implant bridges the fracture generating a force across the bone members. The force (e.g. compression or distraction) is generated by the properties of the implant and the different configurations/geometries of the implant. For example, the implant may have a first configuration for insertion/implantation and a second or third configuration required for generating/creating a particular force magnitude and vector. It may be desirable for improved fusion to provide a force across a majority of the bone surfaces to be fused, not just a particular region. The implant may be indicated for the various bones of the entire skeleton. A "bone fixation device" or "implant" may include any of a variety of devices that secure an object to a bone, including but not limited to staples, bone plates, modular staples, bone screws, pins, blades, suture anchors, and the like.
The Related Art
[0002] The present invention seeks to remedy the problems of the prior art. The invention produces a system that allows use of an implant that may provide a force (e.g. a compressive force) uniformly across bones to be fused. In addition, the present invention includes instrumentation necessary for proper placement and function
of the implant. The invention includes an implant that provides a means for generating a force in more than one direction. Also, the invention incorporates other necessary features into the inserter and implant that are required for final placement. For example the inserter may allow preparation for drill holes, bone screws, etc. and or act to position to the implant in a particular location or position.
SUMMARY OF THE INVENTION
[0003] The present invention includes an implant and a means of insertion and or manipulation. The implant may be a bone staple, bone plate, modular staple, or the like. The implant may have elastic properties or other material properties or geometries that allow the device to have more than one configuration or configurable to various positions when placed on or in the bone. The implant provides a force or forces (e.g. compression or distraction) across two or more bone segments. The inserter or delivery device holds the implant in a configuration that is different from the implanted or final configuration. The terms "fastening device" and "implant" may be used
interchangeably in this application and are not intended to be limiting in nature, and the terms "inserter," "inserting apparatus" and "delivery device" are also used
interchangeably in this application and are not intended to be limiting in nature.
[0004] The implant of the present invention may be constructed of an elastic material or a material that allows the implant to have multiple configurations, such as nitinoi. The ability of the implant to have multiple configurations may be a result of the material properties that have shape memory or elastic properties or it may be a result of manipulation (mechanical, physical, chemical, temperature, electrical or otherwise) of the implant to create multiple configurations. The implant has features for
engaging the bone. These features may include bone screws, leg members, or other features for attaching the implant to bone. The implant may have features for engaging with an inserter or delivery device as instruments for implantation. The implant has a first configuration for insertion, a second configuration for generating a force magnitude and vector in one direction, and a third configuration for generating a force magnitude and vector in the same or a second direction while maintaining the first force generated by the second configuration. The implant may also have a second configuration that generates a force or compression in one or more directions simultaneously. The implant may be attached to the inserting apparatus in such a way to allow the user to determine the order and or timing of providing force in one or more directions. The insertion apparatus may have a feature or features that allow use of drills, screws, drivers, depth gages, etc. while being attached to the implant. The inserter may have a feature or features that allow for preparation of the bone for the implant while the implant is attached to the inserter. The inserting apparatus has features for engaging the implant that may maintain the implant in multiple configurations. For example the inserting apparatus may maintain the implant in a first configuration, second
configuration, or third configuration or a combination of configurations. When the inserting apparatus is removed, the implant is allowed to take on a second, third or additional configuration(s). The inserter may be used to manipulate the implant into a second or third or additional configuration. The implant may take on a second or third or additional configuration(s) while still attached to an inserting apparatus.
[0005] The implant may have multiple configurations, for example one for inserting into the bone and at least a second configuration for compressing, distracting,
controlling spatial orientation or the like of one or more bone segments and a third configuration that may generate a force in the same or different direction than the second configuration. The force generated may be used for compressing, distracting, controlling spatial orientation or the like of one or more bone segments. For the exemplary embodiment described herein, a compressive force may be used for discussion, but should not be considered limiting. Other applications for the current invention exist that may require a force other than a compressive force. The implant may have one or more bridge members of varying configurations. The implant may have protruding members for engaging the bone. The implant may have modular members for engaging bone, such as bone screws or pegs. Based on the description of the invention herein, to those skilled in the art it will be evident that multiple options exist for connecting an implant to bone. The connecting members or features may not necessarily be of the same material as the bridge component. The ability of the current invention to generate a force or forces in the same or different directions may result from movement of the bridge member(s), the connecting member(s) or other member(s) of the implant or fixation device or a combination of different member(s) or feature(s) of the implant.
[0006] The summary of the current invention discusses the merits of the current invention in terms of an implantable device for generating compression, distraction, controlling spacial orientation or the like. The merits of the current invention may also apply to an embodiment of the invention in an external or non-implantable embodiment. The use of the current invention is not limited to just implantable embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Figure 1 is a perspective view of a first embodiment of the current invention depicting an implant with bone screws generating compression by two different actions as indicated by the arrows.
[0008] Figure 2 is a perspective view of a first embodiment of the current invention depicting an implant without bone screws generating compression by two different actions.
[0009] Figure 3a is a top view of a first embodiment of the current invention depicting an implant without the bone screws inserted in a first configuration showing no compressive force generated.
[0010] Figure 3b is a top view of a first embodiment of the current invention depicting an implant without the bone screws in a second configuration showing a first compressive force being generated.
[0011] Figure 3c is a top view of a first embodiment of the current invention depicting an implant without the bone screws in a third configuration showing a second compressive force being generated while maintaining the first compressive force.
[0012] Figure 4a is a perspective view of a first embodiment of the current invention depicting an implant without the bone screws inserted in a first configuration showing no compressive force generated.
[0013] Figure 4b is a perspective view of a first embodiment of the current invention depicting an implant with bone screws inserted in a second configuration showing a first compressive force being generated by convergence of the bone screws.
[0014] Figure 4c is a perspective view of a first embodiment of the current invention depicting an implant with bone screws inserted in a third configuration showing a second compressive force being generated by displacement of the bridge member while maintaining the first compressive force.
[0015] Figure 5a is a front view of a first embodiment of the implant of the current invention showing attachment to an apparatus for insertion and maintaining a first configuration of the implant.
[0016] Figure 5b is a bottom view of a first embodiment of the implant of the current invention showing attachment to an apparatus for insertion and maintaining a first configuration of the implant.
[0017] Figure 6a is a top perspective view of Figure 5a.
[0018] Figure 6b is a bottom perspective view of a first embodiment of Figure 5a.
[0019] Figure 7a is a perspective view of the first embodiment of the implant attached to the insertion/holding device, shown with bone screws inserted and prior to generation of the first compressive force.
[0020] Figure 7b is a perspective view of the first embodiment of the implant attached to the insertion/holding device shown with bone screws inserted and after generation of the first compressive force as a result of allowing the bone screws to converge but prior to generation of the second compressive force.
[0021] Figure 7c is a perspective view of the first embodiment of the implant attached to the insertion/holding device, shown with bone screws inserted and after generation of the first compressive force as a result of allowing the bone screws to
converge and after generation of a second compressive force as a result of allowing the ends of the implant to displace closer together generating a second compressive force at the bridge of the implant.
[0022] Figure 8 is a top view of an implant kit that may be provided for inserting the implant of the current invention into bone segments.
[0023] Figure 9a is a side view of one embodiment of the current invention in one possible location on the bones of the foot.
[0024] Figure 9b is a close-up of Figure 9a showing one embodiment of the current invention in one possible location on the bones of the foot.
[0025] Figure 10 is a top view of the foot shown in Figures 9a and 9b showing in section one embodiment of the current invention in one possible location on the bones of the foot.
[0026] Figure 11 is a top view of a second embodiment of the current invention depicting an implant with means for attaching to instrumentation and a means for attaching to one or more bone engaging means.
[0027] Figure 12 is a side view of the second embodiment of Figure 11 depicting regions and or features for controlling at least one direction of force.
[0028] Figure 13 is a perspective view of the second embodiment shown in Figures 11 and 12.
[0029] Figure 14 is a top view of a third embodiment of the current invention depicting an implant with integral bone engaging means.
[0030] Figure 15 is a side view of the third embodiment of Figure 14 depicting regions and or features for controlling at least one direction of force.
[0031] Figure 16 is a perspective exploded view of a fourth embodiment of the current invention depicting an implant with at least one means for attaching a bone engaging means and a least one integral bone engaging means.
[0032] Figure 17 is a perspective assembled view of a fourth embodiment of the current invention depicting an implant with at least one means for attaching a bone engaging means and a least one integral bone engaging means.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] The present invention includes an implant for generating a multidirectional or multicomponent force across bone or tissue segments. Exemplary embodiments of the current invention are shown in the drawings and discussed below. The implant may be of a configuration similar to a modular staple or bone plate as discussed in the figures. The present invention may employ an apparatus or instrument for inserting the implant that may be pre-assembled or affixed to the implant as shown in Figures 5 and 6. The implant or implants could be held in a particular configuration in the packaging that facilitates engagement with the inserter at time of use. Certain embodiments of the current invention may not require the use of an inserter tool, for example an embodiment made of shape memory nitinol may rely on the ability of the user to activate the shape memory nitinol to generate the multidirectional or
multicomponent forces.
[0034] The implant embodiments described herein may be used in connection with any type of inserter or fixation device, including but not limited to various bone staples, bone plates, etc. that have more than one implant configuration where a force, typically a compressive force, is generated across bone segments.
[0035] Figures 1 and 2 show implant 200. Figure 1 shows the bone screws 100 assembled to implant 200. The implant 200 is shown in a state that exerts forces shown in the direction of 300 and 310. In this exemplary embodiment, the implant 200 has screw holes 230 for attaching a bone screw 100 or other fixation elements. In another embodiment, the implant may have integral staple legs that may be used instead of or in combination with screw holes 230. (See for example Figures 15-17.) Also shown are tabs 240 that may have a slot 250 to facilitate attachment to an insertion device. This attachment tab 240 may be used to hold the implant 200 with the flexing region 220 in a neutral position, i.e. the screw holes 230 are held in a flat orientation. Implant 200 has a flexing region 220 that is located between the screw hole 230 and the bridge member(s) 210. This flexing region 220 may have a nonsymmetrical geometry or other features, such as cutout, slots, embossments, ridges, etc., strategically placed to assist in controlling the direction, force and predictability of the flexing region 220. In this embodiment, the bridge members 210 and the flexing regions 220 define a space 215. The forces may be generated simultaneously or as separate actions. In the exemplary embodiment the forces are generated as separate actions and will simplify the description herein. The first compressive force 300 may be generated when the flexing region 220 is allowed to move thereby allowing the screw holes 230 and bone screws 100 to converge relative to one another. The compressive force 300 may be generated by having a superelastic implant with the screw hole regions 230 manufactured such that they are converging relative to one another when the implant is at rest. Holding the screw hole regions 230 flat may store the
compressive (i.e. converging) energy until they are released and allowed to resume the
converged orientation. With the bone screw regions 230 held fiat or relatively parallel to the bone, the bone screws 100 may be inserted into the bone and maintained parallel relative to one another. Once the bone screws are fully seated, the screw holes 230 may be released from their flat orientation and allowed to resume their converging orientation due to the superelastic aspects of nitinol. In another embodiment, this same effect may be achieved with the shape memory aspects of the nitinol material. In such an embodiment, once the bone screws are fully seated in the bone plate 200, the screw holes 230 may be activated using for example the appropriate activation temperature (e.g. body heat or an external temperature source) and allowed to resume their converging orientation due to the shape memory aspects of nitinol. The magnitude of the force 300 may be dependent on the material of choice, the overall geometry of the implant and or the surgical technique. This compressive force 300 may generate a compressive force that is higher in magnitude at the level of the tips of the screws 100 than at the level of the bone plate 225. Compressive force 310 may be generated when the bridge members 210 are allowed to displace, in this case outwardly, to an open position. This displacement may change the shape of the space 215 thereby creating force 310 which may draw the screw holes 230 closer together generating a
compressive force that may have a greater magnitude at the level of the plate 225 than the level of the tips of the bone screws 100.
[0036] Similar to the mechanism that may be used to generate force 300, force 310 may be generated by having a superelastic implant with the bridge members 210 manufactured such that they may be in an outward or open position when the implant is at rest. Holding the bridge members 210 in a closed position may store the
compressive (i.e. displacement) energy until they are released and allowed to resume the open position or outward orientation. With the bone screws 100 fully seated and secured in bone, the bridge members 210 may be released from their closed orientation and allowed to resume their open orientation due to the superelastic aspects of nitinol. This movement from the closed position to the open position may create a change in the relative spacing between the bone screws 100 thereby generating a displacement that may result in a compressive force 310. In another embodiment, this same effect may be achieved with the shape memory aspects of the nitinol material. In such an embodiment, once the bone screws are fully seated in the bone plate 200, the bridge members 210 may be activated using the appropriate activation temperature (e.g. body heat or an external temperature source) and allowed to resume their open position or outward orientation due to the shape memory aspects of nitinol. The magnitude of the force 310 may be dependent on the material of choice, the overall geometry of the implant (e.g. thickness, width, height, etc.) and or the surgical technique. The unique combination of the forces 300 and 310 may create a more uniform and overall greater compressive force than the forces would individually. The current state of the art is to have an implant device that will generate only one compressive force. The description of the compressive forces 300 and 310 is not intended to be limiting. The forces generated may or may not be uniform or may have varying magnitudes. The particular order of forces generated is also not limiting. The current invention also includes any order or combination of more than one force magnitude and vector.
[0037] Figure 2 shows the implant 200 in the same condition as Figure 1 but without bone screws 100 in place. This figure shows screw holes 230 that are
locking screw holes in this particular embodiment. This embodiment has two bridge members 210 that create a space 215. Based on the description of the invention herein, those skilled in the art will understand that there are numerous shapes that may be created by the bridge members. Furthermore, it is possible to have an implant 200 that may have multiple bridge members or a single bridge member. The single bridge member may be manipulated such that the fixation means (i.e. bone screw, staple legs, etc.) may be brought closer together to create, in this case, a compressive force. In the case of a single bridge member, space 215 may or may not exist.
[0038] The positioning and or orientation and or geometry of opening 215 relative to the bridge members 210 and flexing regions 220 may provide a means for distributing the required stresses within the implant 200 to achieve a desired
compressive force. The position and geometry of opening 215 may be altered within the scope of this invention to manipulate the stress distribution to achieve the desired performance. Within the scope of this invention, the position and geometry of opening 215 may be altered in combination with the thicknesses 205 to manipulate the stress distribution to achieve the desired performance. The amount of desired force generated by the current invention may be accomplished by manipulating individual aspects of the implant geometry and their relative orientations to one another. The geometry and relative orientation of thicknesses 205 may be altered to manipulate the stress distribution within the implant bridges 210 to achieve the desired performance. The geometry and relative orientation of thicknesses 205 may be altered in combination with altering the geometry and relative orientation of the flex regions 220 to manipulate the stress distribution within the implant 200 to achieve the desired performance or force
generated. The geometry and relative orientation of thicknesses 205 may be altered in combination with altering the geometry and relative orientation of flex region 220 and may be in combination with altering the geometry and relative orientation of opening 215 to manipulate the stress distribution within the implant 200 to achieve the desired performance and force generation. Furthermore, the implant widths 208, 209, 211, 212, 213 and or 214 as shown in Figure 3a may also be manipulated in geometry and or orientation either as independent variables or in combination with the previously described aspect or aspects of the implant to manipulate the stress distribution within the implant 200 to achieve the desired performance or force generation.
[0039] Figure 3a depicts a top view of the implant 200 for this particular embodiment. The implant 200 is shown as it would be held prior to releasing and or activating any of the superelastic and or shape memory mechanisms, i.e. in this case shown with no generated forces as it may be held in an inserter for implantation, for clarity the inserter is not shown in this particular view. For clarity, the fixation means bone screws 100 are not included in Figures 3a, 3b or 3c. The implant 200 may have tabs 240 or other means for holding the implant in a flat, non-force generating geometry. This particular embodiment depicts attachment means 230 as locking holes for bone screws 100. However, based on the description of the invention herein, those skilled in the art will understand that the fixation means may be integral to the implant 200, e.g. staple legs, or may include other fixation means such as pegs, blades or other types of bone screws. The flexing region 220 may or may not be of uniform width and or thickness. Flexing region 220 and or the bridge members 210 may have certain features, such as holes, slots, keyways, ribs, bosses, etc. to facilitate and assist in a
predictable means and method of flexing. The space 215 is adjacent to the bridge member(s) 210 that have widths 211 and 212. The width of the bridge member 210 may or may not be uniform. Width 211 may be greater than or less than width 212. The bridge member widths 209 and 210 and widths 213 and 214 may or may not be the same. It is possible that some bridge member widths may be the same while others are greater than or less than the remaining widths. The current embodiment is considered to be made from nitinol or other materials with shape memory or super-elastic material properties, although other materials may achieve the same effect.
[0040] Figure 3b is a top view of implant 200 in a second configuration showing the first compressive force 300. Compressive force 300 may be in a direction that causes the flexing region(s) 220 and or the fixation means, such as bone screws 100 or other such fixation means, to converge (i.e. the tips of the bone screws 100 are brought closer together). Figure 3c is a top view of implant 300 in a third configuration showing the second compressive force 310 and the first compressive force 300. The distance 216 between bridge members 210 has increased while the overall width 400 of implant 200 has decreased. In alternate embodiments, the distance 216 may increase or decrease as needed to generate a particular force. Compressive force 310 may be in a direction that shortens the distance between the flexing region(s) 220 and or the fixation means, such as bone screws 100 or other such means. The order in which the implant generates the various forces may be irrelevant. In this exemplary embodiment force 300 is generated before force 310. The opposite is also possible. Likewise the relative magnitudes of the forces generated is not limiting in nature. One force may be more or less than the other forces generated. As previously described herein, the
relative magnitude and direction of the force or forces generated may depend on the orientation of the implant, the material or combination of materials used in construction, the geometry of the various features of the implant and or the surgical technique. The relative magnitude and direction of the force or forces generated may also be a product of the superelastic and or shape memory properties of a material such as nitinol. The superelastic and or shape memory properties of the material may allow energy to be stored in one configuration only to be released when the implant is allowed to resume or attempt to resume it's at rest or zero stress configuration. One embodiment of the current invention may combine the use of the superelastic and shape memory properties of the nitinol material. For example one force may be generated using the superelastic properties and a second force may be generated using the shape memory properties. In this embodiment the first force 300 and the second force 310 both remain present in the final state or configuration of the implant.
[0041] Figure 4a depicts a perspective view of the implant 200 for this particular embodiment. The implant 200 is shown as it would be held prior to releasing and or activating any of the superelastic and or shape memory mechanisms, i.e. in this case shown with no generated forces for example as it may be held in or by an inserter for implantation, for clarity the inserter is not shown in this particular view. For clarity, the fixation means bone screws 100 are not included in Figure 4a. Figure 4b is a perspective view of implant 200 shown with the bone fixation means, bone screws 100. The implant 200 and bone screws 100 are shown with force 300 that results in the bone screws 100 converging relative to each other to generate a compressive force. One fixation means may converge more or less than another, or one or more may not
converge at all. The force 300 generates a net convergence that may or may not be equally distributed between the fixation means. In some embodiments, three or more fixation means may be utilized. This could be bone screws, staple legs, pegs, blades, or some combination thereof. It may be desirable to have some or all of the fixation means converge. It's possible to have certain fixation members move in a particular direction, while others may or may not move in an alternate direction.
[0042] Figure 4b is a perspective view of implant 200 in a second configuration showing the first compressive force 300. Compressive force 300 may be in a direction that causes convergence of the flexing region(s) 220 and or the fixation means, such as bone screws 100 or other such fixation means.
[0043] Figure 4c is a perspective view of implant 200 in a third
configuration showing the second compressive force 310 and the first compressive force 300. The distance 216 between bridge members 210 has increased while the overall width 400 of implant 200 has decreased. In alternate embodiments, the distance 216 may increase or decrease as needed to generate a particular force. As previously described, force 310 may be in a direction that shortens the distance between the flexing region(s) 220 and or the fixation means, such as bone screws 100 or other such means. The order in which the implant generates the various forces may be irrelevant. In this exemplary embodiment, force 300 is generated before force 310. The opposite is also possible. Likewise the relative magnitudes of the forces generated is not limiting in nature. One force may be more or less than the other forces generated. In this embodiment the first force 300 and the second force 310 both remain present in the final state or configuration of the implant.
[0044] Figure 5a is a front view of implant 200 assembled to an inserter 500. Figure 5a shows implant 200 assembled to inserter 500. The inserter 500 may have a top 510 and a base 520. The inserter 500 is releasably engaged to the implant 200. The inserter 500 has a means 540 that attaches to the implant tab 240 in slot 250 for maintaining the implant 200 in a fiat configuration. Inserter 500 has a means 550 for engaging implant 200 to maintain the distance 216 in closed state.
[0045] Figure 5b is a bottom view illustrating the implant 200 releasably attached to inserter 500. The inserter base 520 has an attachment means 540 that engages slot 250 in the implant attachment means 240. In this embodiment, in the perspective shown, when the inserter 500 is rotated, the inserter engagement means 540 may be withdrawn from the slot 250 (not shown) in the implant attachment means 240. When released, the superelastic properties of the implant 200 will allow the flexing regions 220 of the implant 200 to move towards their zero stress condition or in other words, will allow regions 220 of the implant 200 to flex which may cause the bone screw holes 230 and attached bone screws 100 (not shown) to converge. This action may generate a compressive force 300. As further shown, inserter base 520 has a retractable means 550 that may maintain the implant bridges 210 in their closed or loaded configuration. When the attachment means 550 is retracted or disengaged from the implant bridge members 210, in this embodiment, the superelastic properties allow the bridge members 210 to open or move to their outward configuration. This action may cause the screw holes 230 to move relatively closer to each other thereby generating the compressive force 310. The order in which the implant may be released from the inserter instrument is not limiting. Attachment means 550 may be released first
which may cause the implant bridge members 210 to open or move to their outward configuration. This action may cause the screw holes 230 to move relatively closer to each other thereby generating a displacement. This displacement may shorten the overall length 400 of implant 200. This shortening may be of sufficient magnitude to withdraw the inserter attachment means 540 from the slots 250 of the implant attachment means 240 which may obviate the need to rotate the inserter 500 in a way that would release inserter attachment means 540 from the slots 250 of the implant attachment means 240.
[0046] Figure 6a is a top perspective view of implant 200 assembled to inserter 500. The inserter 500 may have a top 510 and a base 520. The inserter 500 is releasably engaged to the implant 200. The inserter 500 has a means 540 that attaches to the implant tab 240 in slot 250 for maintaining the implant 200 in a flat configuration. Inserter 500 has a means 550 for engaging implant 200 to maintain the distance 216 in closed state. Figure 6b is a bottom perspective view further describing one possible embodiment of the inserter 500 attached to implant 200. This view shows inserter attachment means 550 engaged with the implant bridges 210 and maintaining them in a first configuration or closed state. Also described in Figure 6b is the inserter attachment means 540 which may be slidably engaged in slot 250 of implant attachment means 240 maintaining regions 220 and bone screw holes 230 in a flat orientation or configuration. To those skilled in the art, it will be obvious based on the description of the invention herein that there are numerous mechanisms and
embodiments for releasably attaching to the implant to maintain the implant in a loaded and or stressed state prior to releasing the implant and or allowing the implant to
achieve a force generating state. Figure 6a shows holes 530 that permit insertion of the bone screws 100 or other fixation means.
[0047] Figure 7a is a perspective view of the inserter 500 shown releasabiy attached to implant 200 with bone screws 100 in place. As shown, the inserter 500 maintains the implant in a neutral state with the fixation means, bone screws 100, in a parallel, non-force generating configuration. Figure 7b shows inserter 500 being released from implant 200 by a twisting motion 600. This motion 600 releases the engagement means 540 from the implant attachment tabs 240 while maintaining attachment means 550 with the implant. Once the engagement means 540 releases the implant, the flexing region 220 is permitted to flex thereby generating force 300. In this particular exemplary embodiment, the force 300 causes the bone screws 100 to converge thereby generating a compressive force across the bone segments. Figure 7b illustrates the implant 200 and inserter 500 prior to fully releasing the implant 200 from inserter 500. Figure 7c is a perspective view of the first embodiment of the implant 200 detached from the insertion/holding device 500. The first releasing action 600 has already been completed and as shown a second releasing action 610 is used to fully disengage the inserter 500 from the implant 200 thereby allowing the bridge members 210 to move, increasing the distance 216 and drawing the bone fixation means 100 closer together which decreases the overall width 400 of the implant resulting in a force 310. The releasing action 610 may allow the inserter attachment means 550 to be retracted within the inserter base 520. In this particular exemplary embodiment, force 310 is an additional compressive force further compressing the bone segments.
[0048] The previous description is for a particular embodiment that is considered to be manufactured from a material with elastic properties, such as super elastic nitinol. However this description is not intended to be limiting in nature. Those skilled in the art will understand based on the description of the invention herein that the same may be accomplished using a material for example with shape memory aspects, such as shape memory nitinol. Other materials currently exist or may exist that have desirable material properties that will achieve the intended function of the current invention. Still other embodiments of the current invention may provide more than one force that is generated simultaneously as opposed to the stepwise manner as described herein. The order in which the forces are generated is also not intended to be limiting in nature. The use of an inserter/holding device may or may not be optional. The specific details of the inserter may vary greatly depending of the chosen embodiment. The exemplary embodiment described herein, expands on a two force configuration. Those skilled in the art will find it obvious based on the description of the invention herein that multiple forces may or may not be beneficial depending on the intended application. They will also find it obvious that the magnitude and direction of the resulting force vectors may or may not be equivalent or may or may not be additive. It may be beneficial to have multiple forces generated to create more uniform and predictable forces than those currently available in the state of the art devices. Still further, the exemplary embodiment described herein considers a design with two fixation means or bone screws. Other embodiments may include two or more fixation means that may be of the same style (such as bone screws, bone pegs, blades, staple legs, etc.) or of varying styles or some combination thereof. For fixation means that are modular in
nature, they may or may not be made of the same material as the implant described herein.
[0049] Referring to Figure 8, the implant of the current invention may be packaged as an implant kit with the associated instruments needed for a successful implantation. A kit of this sort may be provided as a sterile single use kit for efficiency and cost effectiveness. Such a kit may include the implant or implants, bone screws or other means for fixing the plate to the bone, the necessary drills or reamers for preparing the bone for receiving the implant and bone screws, any necessary drill guides and drivers and an inserter for facilitating implantation of the implant into the bone. Figure 8 shows one embodiment of an implant kit 1000 that may be used to provide the end user with the implants and necessary associated instruments for successfully implanting an implant of the current invention. Such a kit may include one or more implants 1100 similar to the embodiments described herein preassembled to an inserter 1150. The kit may also include bone screws 1125 of various lengths and or diameters, a drill 1200, a drill guide 1300, a driver 1250 and a provisional fixation pin 1400. The kit may also include an insertion tool or inserter 1150 for facilitating insertion of the implant 1100 into a bone segment(s). One embodiment of the kit may have the implant 1100 preassembled to the insertion tool 1150. The kit may be assembled in a tray 1500. Once the end user opens the kit, the surgical technique may include the following steps. After exposure of the operative site, the osteotomy or fracture may be reduced and held in place. The drill guide or reamer guide may be placed across the fusion site with both guide tubes against the bone. The first hole is drilled to final depth by advancing the drill or reamer to a predetermined depth or until a depth stop hits the
top of the guide. A provisional fixation pin may be placed in the prepared hole to help maintain reduction while the additional holes are prepared. Another option may allow the holes to be prepared directly through the inserter 1150 obviating the need for an ancillary drill guide. This step of preparing the bone may include the need or use of a depth gage to select the appropriate sized bone screw. Once the holes have been prepared, the implant 1100 may be fixed to the bone, with bone screws 1125. The bone screws 1125 may be inserted through the implant and into the bone segments. The implant 1100 may be pre-assembled or loaded onto the inserter tool 1150. The implant 1100 and bone screws 1 125 should be fully inserted until flush against the surface of the bone. The implant may then be released from the inserter tool thereby generating the prescribed forces and generating compression across the bone segments. Once implantation is complete the inserter and remaining instruments may be discarded or recycled.
[0050] Figures 9a and 9b illustrate one embodiment of the current invention 1800 in one possible location on the bones of the foot 1850 that may have been positioned according to the technique described herein. Figure 9a illustrates a side view of foot 1850 with the implant 1800 spanning the joint line or fracture line 1851. The implant 1800 may be fastened to the bones 1855 and 1856 with bone screws 1810. Figure 9b is a close up view of bones 1855 and 1856 illustrating the implant 1800 spanning joint line or fracture line 1851. The implant 1800 may be fastened to the bones 1855 and 1856 with bone screws 1810. Is this exemplary embodiment, the implant 1800 may have bridge members 1821 in an open configuration that may cause a shortening or displacement between the relative positions of bone screws 1810 which
may bring the two bones 1855 and 1856 in apposition for possible fusion of joint line or fracture line 1851. The figure further shows flex region 1820 of implant 1800 in a flexed position that may bring the bone screws 1810 in a converging position relative to one another thereby possibly bringing bones 1855 and 1856 even further into apposition for possible fusion of joint line or fracture line 1851. Figure 10 is a top view of foot 1850 and bones 1855 and 1856. This figure shows flex regions 1820 of implant 1800 in a flexed position that may bring the bone screws 1810 in a converging position relative to one another thereby possibly bringing bones 1855 and 1856 into apposition for possible fusion of joint line or fracture line 1851.
[0051] Figure 11 shows a top view of a second embodiment of the current invention, implant 2000, having a top surface 2041 and a space 2040. Figures 11 , 12 and 13 show the implant 2000 in a flat configuration. Space 2040 is defined by bridge members 2042 and flexing regions 2055. As previously described herein, the shape of space 2040 may vary by either contracting or expanding to create a movement or force in a predetermined direction. Implant 2000 has means 2030 for engaging bone fixation means of varying sorts. For example, means 2030 may be non-locking holes, threaded locking holes, interference holes, tapered holes or other mechanical means for connecting bone engagement means such as pegs, screws, blades, etc. Implant 2000 may have one or more means 2020 for engaging a means of insertion as previously described herein. Implant 2000 may have means 2010 for engaging or indexing the implant with an inserter, driver or other means of insertion or holding. Means 2010 may also be used to change the shape of space 2040. In this embodiment, means 2010 may be used to compress the space 2040 thereby creating a force that will maintain
means 2030 apart relative to one another. This configuration may be maintained while the bone fixation means are inserted into bone. Once the implant 2000 is affixed to the bone with the bone fixation means, the means by which the means 2010 are maintained apart may be released thereby allowing the distance between means 2030 to shorten creating a compressive force. Figures 12 and 13 show implant 2000 having a top surface 2041 and a bottom surface 2045. Bottom surface 2045 may be interrupted by means 2050. Means 2050 is positioned to provide a predetermined bend region for predictably controlling a motion and or direction of an alternate action or configuration of implant 2000. In this particular embodiment, means 2050 is shown positioned between the space 2040 and bone fixation means 2030 but may be positioned at any place on the implant where it is desirable to control the direction and motion of a first or second configuration.
[0052] Figures 14 and 15 show a third embodiment of the current invention, implant 2100, having a top surface 2105 and a bottom surface 2106. Figure 15 shows implant 2100 in a closed or compressed state. Implant 2100 has a space 2140 that may be defined by bridge members 2142 and flexing regions 2120. As previously described herein, the shape of space 2140 may vary by either contracting or expanding to create a movement or force in a predetermined direction. Implant 2100 has means 2150 for engaging bone or other tissue. Means 2150 is integral with the implant 2100. The fixation means 2150 may be varying geometries. For example means 2150 may be circular, rectangular, square, or other cross-sectional geometries. Means 2150 may be uniform in shape across the entire feature or may taper or may possess grooves, ridges, teeth, etc. Implant 2100 may have one or more means 2155
for engaging a means of insertion and or for creating bending regions positioned to provide a predetermined region for predictably controlling a motion and or direction of a second action or configuration of implant 2100. In this particular embodiment, means 2155 is shown positioned between the space 2140 and bone fixation means 2150 but may be positioned at any place on the implant where it is desirable to control the direction and or motion of a first and or second configuration and or other alternate configurations. In this particular embodiment, means 2155 may perform a combination of functions which may include acting as a connection point for an inserter, holder, driver or other instrument and or acting as a predetermined region to control the direction and or motion of a first and or second implant configuration and or other alternate configurations. Implant 2100 may or may not have a means similar to the previously described means 2010 for engaging or indexing the implant with an inserter, driver or other means of insertion or holding. As previously described herein space 2140 may compress or expand thereby creating a force that will maintain means 2150 apart. This configuration may be maintained while the implant is also held in a second configuration for insertion into bone. For example, means 2150 may be held parallel relative to one another while space 2140 is compressed. Maintaining implant 2100 is these multiple configurations prior to insertion would maintain the means 2150 parallel and at a fixed separation distance. Once implanted, the space 2140 may be allowed to change or expand thereby shortening the distance between the fixation means 2150 creating a compressing force and or action. Once implanted, the engaging means 2150 may no longer be maintained parallel and may be allowed to resume a compressed or closed configuration. Bending region 2120 and 2155 may be allowed to revert to a
closed and or converging state thereby creating an alternate configuration that will create compression.
[0053] Figures 16 and 17 show a fourth embodiment of implant 2200 that combines a means 2230 for connecting to a bone engaging means 2210 and an integral bone engaging means 2250. Figure 16 is an exploded view of the construct where bone engaging means 2210 is a typical bone screw, but may be a peg, blade, nonlocking screw, locking screw, etc. Integral bone fixation means 2250 is shown as a square cross-section similar to a typical staple leg but could be any shape or
configuration as previously described herein. Figure 17 shows the assembled construct in a closed or compressed configuration.
[0054] Based on the description contained herein, it will be apparent to those skilled in the art that the current invention is not limited by the exemplary applications. The current invention may have various embodiments of varying size and various combinations, shapes and configurations are possible for varying applications. For example, an implant may have one or more integral bone engaging means in combination with one or more means for connecting to a bone engaging feature. In addition, the embodiments described herein are shown with two means for connecting to bone engaging devices but based on the description contained herein, it will be apparent to those skilled in the art that various combinations and or numbers of connection means to bone engaging features are within the scope of the current invention. Furthermore, the implant may be made of a material that may have elastic or spring properties that allow the implant to have more than one configuration. The current invention may or may not be achieved through the inherent material properties
of the implant material. The implant may achieve this alternate configuration by transitioning from, for example, a first configuration to a second configuration to a third configuration. Where the first configuration may be that as attached to the inserter or delivery device and the second configuration may be a configuration that generates a first force and where the third configuration may be a configuration that generates a second force that may or may not be of the same magnitude and or direction as the first force. The embodiments described herein are not intended to be limiting. The transition from one configuration to another configuration or configurations may be one distinct transition or more than one distinct transition and there may be multiple forces of the same or different magnitudes and directions as will be apparent to those having skill in the art based on the disclosures herein. The transition may be due to the inherent material properties or achieved by a manipulation of the material or a combination thereof.
[0055] The embodiments described herein can be manufactured from a number of different materials or combinations of materials. Nitinol, for example, possesses material properties, such as shape memory and or super elasticity that may provide the inherent properties to allow an embodiment to have multiple configurations with or without an external mechanical manipulation. Still other materials such as PEEK or other polymers may also possess material properties beneficial for the embodiment described herein. A combination of materials may also be preferred. For example, a nitinol plate with titanium or PEEK screws may be the materials of choice for some embodiments. Based on the description of the invention herein, those skilled in the art will be aware of the typical materials and combinations of materials applicable to the
current invention as well as the mechanism of action of the current invention as it may related to superelastic nitinol, shape memory nitinol, or the like.
[0056] The exemplary embodiments described herein are not intended to be limiting. To those skilled in the art the benefits of the invention are apparent, based on the description of the invention herein. Furthermore based on the description of the invention herein those skilled in the art will appreciate that the intent of this invention may be realized in other embodiments not necessarily described herein.