Patent ID: 12239350

This disclosure describes exemplary embodiments in accordance with the general inventive concepts and is not intended to limit the scope of the invention in any way. Indeed, the invention as described in the specification is broader than and unlimited by the exemplary embodiments set forth herein, and the terms used herein have their full ordinary meaning.

DETAILED DESCRIPTION

The general inventive concepts will now be described with occasional reference to the exemplary embodiments of the invention. The general inventive concepts may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the general inventive concepts to those skilled in the art.

As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. The term “proximal” as used in connection with any object refers to the portion of the object that is closest to the operator of the object (or some other stated reference point), and the term “distal” refers to the portion of the object that is farthest from the operator of the object (or some other stated reference point). The term “operator” means and refers to any professional or paraprofessional who delivers clinical care to a medical patient, particularly in connection with the delivery of care.

Anatomical references as used herein are intended to have the standard meaning for such terms as understood in the medical community, and generally, any and all terms providing spatial references to anatomical features shall have meaning that is customary in the art. For example, the application may include reference to the following terms: “cephalad,” “cranial” and “superior” indicate a direction toward the head, and the terms “caudad” and “inferior” indicate a direction toward the feet. Likewise, the terms “dorsal” and “posterior” indicate a direction toward the back, and the terms “ventral” and “anterior” indicate a direction toward the front. And the term “lateral” indicates a direction toward a side of the patient. The term “medial” indicates a direction toward the mid line of the patient, and away from the side, the term “ipsalateral” indicates a direction toward a side that is proximal to the operator or the object being referenced, and the term “contralateral” indicates a direction toward a side that is distal to the operator or the object being referenced.

“Patient” is used to describe an animal, preferably a human, to whom treatment is administered, including prophylactic treatment with the compositions of the present invention. “Concave” is used herein to describe an indented surface without reference to the specific shape of the indented surface. As non-limiting examples, the concave face may be tubular with a round cross section, oval cross section, square cross section, or rectangular cross section.

Unless otherwise indicated, all numbers expressing quantities, properties, and so forth as used in the specification, drawings and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless otherwise indicated, the numerical properties set forth in the specification and claims are approximations that may vary depending on the suitable properties desired in embodiments of the present invention. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the general inventive concepts are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical values, however, inherently contain certain errors necessarily resulting from error found in their respective measurements.

References to visualization using radiography as may be described in the exemplary techniques herein are merely representative of the options for the operator to visualize the surgical field and the patient in one of many available modalities. It will be understood by one of ordinary skill in the art that alternate devices and alternate modalities of visualization may be employed depending on the availability in the operating room, the preferences of the operator and other factors relating to exposure limits. While confirmation of instrument placement in the course of the technique is appropriate, the frequency and timing relative to the sequence of steps in the technique may be varied and the description herein is not intended to be limiting. Accordingly, more or fewer images, from more or fewer perspectives, may be collected.

One of ordinary skill will appreciate that references to positions in the body are merely representative for a particular surgical approach. Further, some references herein are made in the context of the representative images shown in the drawings. Fewer or additional instruments, including generic instruments, may be used according to the preference of the operator. Moreover, references herein to specific instruments are not intended to be limiting in terms of the options for use of other instruments where generic options are available, or according to the preference of the operator.

The present application describes various embodiments of devices for joint and other bone fixation. In some particular embodiments, devices for fixation of the sacroiliac joint are provided. It will be appreciated that the examples and drawings, as shown herein, may be described in reference to use in applications for sacroiliac joint fusion, though the devices as disclosed herein may be used in any of a variety of other orthopedic applications, and may be used alone, or as an adjunct to devices used for other fixation or correction, such as, for example, in spine fusion surgery, to help hold other implants in place.

Fixation Implants

In accordance with various embodiments, the invention provides a fixation implant that comprises fixation member having a proximal head and a shank with a distal tip. The fixation implant is advantageously used for accomplishing fixation of tissue, such as bone tissue, in some examples including adjacent bones at a joint such as the sacroiliac joint, or bone fracture fragments. The implant provides enhanced resistance to rotational motion, rotational migration and pull out as compared with other fixation member designs, this advantage owing to one or more of increased bone engagement surface, enhanced opportunity for osseo-integration, and enhanced bone purchase as a result of the extensively enhanced surface area of the three-dimensional open structure of at least a portion of the implant. The fixation implant includes one or more of head and shank features modeled to resemble the open and interconnected porosity features of trabecular bone in a variety of different embodiments.

In accordance with the various embodiments, the shank of the fixation member includes one or more openings or slots through the shank, in some embodiments arranged as a plurality around the periphery of the shank, to further enhance bony ingrowth. The openings are referred to herein as an open core and are formed of an open network body that provides a framework comparable to that of trabecular bone. As further described herein, an open core may be formed within any of the head and the shank portions and comprises at least one open network body. In some particular embodiments, the shank portion includes an open core comprising an open network body and one or both of the head and distal tip are solid (i.e., do not include an open network body) and may include a through cannula. In some embodiments, an open network body may be selected from one or a combination of: at least one elongate helix; an organized arrangement of trusses; a random arrangement of trusses; a framework or scaffold of random open and interconnected pores; and, a porous framework of random open and interconnected pores. Thus, in some embodiments, the entire fixation implant may have an open core formed of at least one type of open network structure or combinations thereof.

In accordance with the various embodiments, the open network body of the fixation implant allows materials to move into or out of the open core of the shank, the materials including bone fillers and other materials that would encourage bony ingrowth. Of course, in some such embodiments, the fixation implants may be provided without any filler materials. In accordance with the various embodiments, all or any portion of the fixation implant may be formed of one or more of a metal and a polymer. In particular, the head, the shank, the open core and the distal tip may be partially or completely formed from one or a combination of materials selected from metal and a polymer. In some particular examples, all or a portion of the materials forming the trabecular body may be osseo-inductive, selected from materials such as titanium, or others. And in some embodiments, the entire fixation implant may have an open core formed of a metal, a polymer, or combinations of these with or without other additive materials such as hydroxyapatite, and the open core may be open or closed.

An open network body has an open and interconnected matrix that allows communication between all bony material 360 degrees around the bone to optimize complete bony integration. This is advantageous over existing screw designs that have one or a series of fenestrations in an otherwise solid body of the shank, such fenestrations providing incomplete (i.e., less than 360 degree) engagement with bone. The three-dimensional structures of the open network body can provide greater support and stress distribution as compared to through holes and other fenestrations in the body of the shank of a conventional hollow screw that is designed to encourage bony ingrowth. Similar to the function of the trabeculae in bone, the open network structures of the open network body can allow for more even stress distribution than fenestrations would permit while also presenting open portions for bony ingrowth circumferentially at all points of circumferential contact with bone

Referring now toFIG.1, an exemplary embodiment of a fixation member100is shown. The fixation member100is characterized in having a head110, and a shank130with an external thread140over an open core comprising a helical body150having the shape of a helix along the length of the shank130, the fixation member100generally resembling the overall shape of a bone screw. According to the various embodiments, the open core as shown inFIG.1in the form of a helical body150provides an example of an open network body according to the invention that is adapted to encourage bony growth through the implant when it is fixed in bone. As shown inFIG.1and the other embodiments, the thread140is disposed on and integral with the helical body150forming the open network body of the open core, such that the helical body150is at least partially visible along the length of at least a portion of the shank130in the gaps between the thread140, providing access into the helical body150to allow tissue infiltration and bony ingrowth therein.

Referring again toFIG.1, in the exemplified embodiment, the fixation implant100includes a proximal head110that has a generally spherical in shape, and comprises a center through cannula180that passes from the head110through the distal tip160, and a tool recess120for engaging a driving instrument. In alternate embodiments the head shape may be generally hemispherical, generally cylindrical, generally conical, and generally frustoconical. Each of the head110and distal tip160is cannulated and otherwise solid (i.e., it is not formed of an open network). In alternate embodiments, one or more of the distal tip160and the head110may be non-cannulated and solid, or may be cannulated and partially or entirely formed from one of a solid and an open network. Referring now toFIG.7-FIGS.9Aand B, as shown in alternate depicted embodiments, for example as shown inFIG.7, the head710and distal tip760are solid (not cannulated).

The exemplified fixation implant100includes a shank130having a length defined between the proximal head110and a distal tip160and a shape that is generally cylindrical that does not taper from proximal to distal, with a distal tip160that is a tapered frustoconical shape. In alternate various embodiments, the shank shape is selected from generally cylindrical, generally conical and generally frustoconical. It will be appreciated that the shape and proportions of the implant are not intended to be limiting and that the relative dimensions of each of the head, shank and distal tip portions of the various embodiments may vary. In the various alternate embodiments, all or only a portion of the shank130may have one or more an external thread140arranged around the open core along the length of the shank130.

In the various embodiments according to the disclosure, the open core is formed with an open network structure selected from one or a combination of: at least one elongate helix; an organized arrangement of trusses; a random arrangement of trusses; a framework or scaffold of random open and interconnected pores; and, a porous framework of random open and interconnected pores. Further, the open core may be open in its center (whether or not one or both of the head and the distal tip are cannulated), or it may be solid, or it may include an open network structure as described herein above, or it may comprise a solid inner wall, such as a cylindrical wall, or a fenestrated wall, or a combination of these. As briefly described herein, each ofFIG.1,FIG.3,FIG.5,FIG.6andFIG.7depicts a fixation implant in which the open core has an open center (whereFIG.7is the one example in which the head and the distal tip are not cannulated), and, each ofFIG.2andFIG.4depicts a fixation implant in which the open core includes at its center a solid cylindrical wall that is cannulated, andFIG.8andFIGS.9Aand B each depict fixation implants in which the open core has a center that is continuously filled with the open network, and in which the head and the distal tip are not cannulated.

It will be appreciated by one of ordinary skill in the art that while each of the depicted embodiments as shown in the drawings include various combinations of the features that include a head and a distal tip and a shank comprising one or open network bodies, there are numerous possible embodiments having combinations of features that are not shown in the drawings. Thus, in various alternate examples, the fixation implant may have any one or more of the following configurations along at least a portion of its length between the head and the distal tip, from proximal to distal: a through cannula surrounded by an open network body with exterior threading; a through cannula surrounded by a solid or fenestrated wall that is surrounded by an open network body with exterior threading; a solid that is surrounded by an open network body with exterior threading; and, a continuous open network body with exterior threading. Thus,FIG.1is an example of a fixation implant that has a through cannula from the proximal head portion through the distal tip, each of the proximal head portion and tip being otherwise solid (not an open network) and the shank comprises a void (the through cannula) surrounded by an open network body.

Referring now toFIG.2, yet another embodiment of a fixation implant200is shown being characterized in having a shank230comprising an external thread240over an open core, the open core comprising a helical body250having the shape of a helix along the length of the shank230, the helical body250having within it a solid-walled inner cylindrical through channel270. In the depicted embodiment, each of the head210and the distal tip260are cannulated280, and the head210includes a tool recess220for engaging a driving instrument.

Referring now toFIG.3, yet another embodiment of a fixation implant300is shown being characterized in having a shank330comprising an external thread340over an open core, the open core comprising an organized truss body350. In the depicted embodiment, each of the head310and the distal tip360are cannulated380, and the head310includes a tool recess320for engaging a driving instrument.

Referring now toFIG.4, yet another embodiment of a fixation implant is shown having a shank430comprising an external thread440over an open core, the open core comprising an organized truss body450that has a solid-walled inner cylindrical through channel470. In the depicted embodiment, each of the head410and the distal tip460are cannulated480, and the head410includes a tool recess420for engaging a driving instrument.

FIG.5shows yet another embodiment of a fixation implant500, the fixation implant500having a shank530characterized in having an external thread540over an open core comprising a dual helical body550that comprises two entwined helices, each helix having a different pitch. In the depicted embodiment, each of the head510and the distal tip560are cannulated580, and the head510includes a tool recess520for engaging a driving instrument.

Referring now toFIG.6, yet another embodiment of a fixation implant600is shown being characterized in having a shank630having an external thread640over an open core comprising a disorganized truss body650with a solid-walled inner cylindrical through channel670that is fenestrated along its length and open to the threading as shown in the lower panel ofFIG.6. In the depicted embodiment, each of the head610and the distal tip660are cannulated680, and the head610includes a tool recess620for engaging a driving instrument.

Referring now toFIG.7, yet another embodiment of a fixation implant700is shown being characterized in having a shank730having an external thread740over an open (containing a void) helical body750, where in the depicted embodiment, each of the head710and the distal tip760are not cannulated, and the head710includes a tool recess720for engaging a driving instrument.

Referring now toFIG.8, yet another embodiment of a fixation implant800is shown being characterized in having a shank830having an external thread840over an open and continuous disorganized truss body850wherein the shank830, the head810and the distal tip860are not cannulated, and the head810includes a tool recess820for engaging a driving instrument.

Referring now toFIG.9A, three alternate embodiments of a fixation implant are shown. Referring to the top image ofFIG.9A, the depicted embodiment is a non-cannulated fixation implant900having a head910and a distal tip960that are not cannulated, and the head910including a tool recess920for engaging a driving instrument, the implant also having exterior threading940and an open scaffold body950comprising a scaffold of random open and interconnected pores that is an engineered model based on the porous network of trabecular bone. Referring again toFIG.9A, in the middle panel is a fixation implant900′ that is a variation of the fixation implant900shown above, wherein the shank930includes threading940along its length and only a portion of the length of the shank930is formed of the open scaffold body950and a portion of the shank930is a through solid970. Referring to the bottom image ofFIG.9A, the depicted embodiment is a non-cannulated fixation implant1000having a head1010and a distal tip1060that are not cannulated, and the head1010including a tool recess1020for engaging a driving instrument, the implant also having exterior threading1040and a porous body1050comprising a framework of random open and interconnected pores that closely mimics the porous network of trabecular bone.

Referring now toFIG.9B, three alternate embodiments of a fixation implant are shown, each in a side cross sectional view. The uppermost image depicting an cannulated fixation implant1000having a solid-walled1070inner cylindrical through channel1080, the implant100having exterior threading1040and an interior framework of random open and interconnected pores. Referring again toFIG.9B, the middle image depicts an cannulated implant1000having a solid-walled1070inner cylindrical through channel1080, the implant having a cylindrical head1010, exterior threading1040from the head1010to the distal tip1060and an interior framework of random open and interconnected pores, shown in a side cross sectional view. Referring again toFIG.9B, the third and bottom image depicts an cannulated implant1000having a solid-walled1070inner cylindrical through channel1080, the implant1000having a cylindrical head1010, exterior threading1040at the head1010and on a portion of the shank1030and at the distal tip1060and an interior framework of random open and interconnected pores.

Referring now toFIG.10-FIG.16, each figure depicts and alternate embodiment of a fixation implant2000, each in a side cross sectional view.

The implant2000ofFIG.10is a headless type cannulated screw with a cylindrical threaded head2010, a threaded self-tapping distal tip2060, an inner cylindrical through channel2080with a solid inner wall2070and includes along a portion of the shank2030an outer framework of random open and interconnected pores2050that is between outer solid threads2040and the solid inner wall2070. As shown, each of the head2010, a proximal portion of the shank2030, a central to distal portion of the shank2030and the distal tip2060each has a different thread. The head2010may include a tool recess2020.

The implant2000ofFIG.11is a headless type cannulated screw with a cylindrical threaded head2010, a threaded self-tapping distal tip2060, an inner cylindrical through channel2080with a solid inner wall2070and includes along the shank2030from below the head2010to above the distal tip2060of the shank2030an outer framework of random open and interconnected pores2050that is between outer solid threads2040and the solid inner wall2070. As shown, each of the head2010, a proximal portion of the shank2030, a central to distal portion of the shank2030and the distal tip2060each has a different thread.

The implant2000ofFIG.12is a headless type cannulated screw with a cylindrical threaded head2010, a threaded self-tapping distal tip2060, an inner cylindrical through channel2080with a wall formed of a framework of random open and interconnected pores2050along a portion of the length of the shank2030, the outer framework of random open and interconnected pores2050bounded on the exterior by an outer solid thread. As shown, each of the head2010, a proximal portion of the shank2030, a central to distal portion of the shank2030and the distal tip2060each has a different thread.

The implant2000ofFIG.13headless type cannulated screw with a cylindrical threaded head2010, a threaded self-tapping distal tip2060, an inner cylindrical through channel2080with a solid inner wall2070and includes along a portion of the shank2030an outer framework of random open and interconnected pores2050that is between outer solid threads2040and the solid inner wall2070. The shank2030includes along its length a series of circular and slotted fenestrations3000that extend from the exterior trough to the cannula. As shown, each of the head2010, a proximal portion of the shank2030, a central to distal portion of the shank2030and the distal tip2060each has a different thread2040.

The implant2000ofFIG.14headless type cannulated screw with a cylindrical threaded head2010, a threaded self-tapping distal tip2060, an inner cylindrical through channel2080with a solid inner wall2070and includes along a portion of the shank2030an outer framework of random open and interconnected pores2050that is between outer solid threads2040and the solid inner wall2070. As shown, each of the head2010, a proximal portion of the shank2030, a central to distal portion of the shank2030and the distal tip2060each has a different thread, and the thread along the central to distal portion of the shank2030is interrupted and includes at least one short unthreaded portion3100.

The implant2000ofFIG.15headless type cannulated screw with a cylindrical threaded head2010, a threaded self-tapping distal tip2060, an inner cylindrical through channel2080with a solid center2090, and includes along a portion of the shank2030an outer framework of random open and interconnected pores2050that is between outer solid threads2040and the solid interior. As shown, each of the head2010, a proximal portion of the shank2030, a central to distal portion of the shank2030and the distal tip2060each has a different thread.

The implant2000ofFIG.16is a cannulated screw with an unthreaded disc shaped head2010, a threaded self-tapping distal tip2060, an inner cylindrical through channel2080with a solid inner wall2070and includes along a portion of the shank2030an outer framework of random open and interconnected pores2050that is between outer solid threads2040and the solid inner wall2070. As shown, each of the head2010, a proximal portion of the shank2030, a central to distal portion of the shank2030and the distal tip2060each has a different thread.

With reference to some embodiments, the fixation implant2000includes a shank2030having a length from a proximal end to a distal end; a head2010that is integral with the shank2030at its proximal end and has a tool recess2020configured for engagement with a driving instrument; a tip2060that is integral with the shank2030at its distal end; and at least one thread extending along an external surface of the shank2030. According to some embodiments, at least a portion of the shank2030, or each of the shank2030, the tip2060, and the head2010have an open network body comprising a scaffold of open and interconnected pores2050mimicking a trabecular bone structure. According to some embodiments, the head2010has a headless configuration such that the head2010lacks an enlarged outer diameter relative to the shank2030. According to some embodiments, at least a portion of the shank2030and the tip2060each have an open network body comprising a scaffold of open and interconnected pores2050mimicking a trabecular bone structure.

According to some embodiments, the head2010has a headless configuration such that the head2010lacks an enlarged outer diameter relative to the shank2030.

According to some embodiments, the at least one thread2040is formed from metal and wherein the open network body comprising a framework of random open and interconnected pores2050is formed from at least one of a metal or a biocompatible polymer selected from the group consisting of: PEK, PEEK, PAEK, and combinations thereof.

According to some embodiments, the at least one thread2040is integral with a surface of the open network body comprising a scaffold of open and interconnected pores2050.

According to some embodiments, the open network body comprising a scaffold of open and interconnected pores2050is exposed in gaps between the at least one thread.

According to some embodiments, at least a portion of the length shank2030is comprised of the open network body comprising a scaffold of open and interconnected pores2050without any solid center2090or inner cannulated solid wall2070.

According to some embodiments, all of the shank2030is comprised of the open network body comprising a scaffold of open and interconnected pores2050, and the shank2030may be cannulated.

According to some embodiments, all of the tip2060is comprised of the open network body comprising a scaffold of open and interconnected pores2050.

According to some embodiments, the implant2000includes a cannula comprising an inner cylindrical through channel2080formed through at least a portion of the shank2030. According to some such embodiments, the inner cylindrical through channel2080is formed through the fixation implant2000from and including the head2010through shank2030and to and including the tip2060.

According to some embodiments, the shank2030is fenestrated.

According to some embodiments, a fixation implant2000includes a shank2030having a length from a proximal end to a distal end; a head2010that is integral with the shank2030at its proximal end and has a tool recess2020configured for engagement with a driving instrument; a tip2060that is integral with the shank2030at its distal end; and at least one thread extending along an external surface of the shank2030. According to some embodiments, at least a portion of the shank2030has an open network body comprising a scaffold of open and interconnected pores2050mimicking a trabecular bone structure. According to some embodiments, the head2010has a headless configuration such that the head2010lacks an enlarged outer diameter relative to the shank2030, and the tip2060and the head2010are non-porous and formed from solid material.

According to some embodiments, the shank2030is free from a cannula passing therethrough.

According to some embodiments, the shank2030is free of fenestrations3000, the at least one thread is continuous from the head2010to the tip2060, and the tip2060is self-tapping.

According to some embodiments, the at least one thread is interrupted by at least one short unthreaded portion along the shank2030.

According to some embodiments, a fixation implant2000includes a cannula comprising an inner cylindrical through channel2080formed through at least a portion of the shank2030, wherein the shank2030is free of fenestrations3000. According to some embodiments, the shank2030is fenestrated.

According to some embodiments, the at least one thread is continuous from the head2010to the tip2060, the tip2060is self-tapping, and the fixation implant2000further comprising a cannula comprising an inner cylindrical through channel2080formed through at least a portion of the shank2030.

According to some embodiments, the shank2030is free of fenestrations3000, the at least one thread is continuous from the head2010to the tip2060, the tip2060is self-tapping, and the fixation implant2000further comprising a cannula comprising an inner cylindrical through channel2080formed through at least a portion of the shank2030.

According to some embodiments, a fixation implant2000includes a shank2030having a length from a proximal end to a distal end; a head2010that is integral with the shank2030at its proximal end and has a tool recess2020configured for engagement with a driving instrument; a tip2060that is integral with the shank2030at its distal end; and at least one thread extending along an external surface of the shank2030. According to some embodiments, at least a portion of the shank2030has an open network body comprising a scaffold of open and interconnected pores2050mimicking a trabecular bone structure, the head2010is a partially spherical head2010or flat, and the tip2060and the head2010are non-porous and formed from solid material.

In accordance with various embodiments, the open and porous open core of the fixation implant may be formed by any of a variety of processes, including additive (3D) manufacturing, conventional machining, and assembly of subparts. And in some embodiments, the open and porous open core of one or both the head and the shank are formed separately, wherein any threads on the fixation implant are formed from a material selected from metal, and the open core is separately formed using composite material that includes one or more of biocompatible polymers such as PEK, PEEK and PAEK, and other biodegradable polymers, bone material, BMP, and the like.

In some representative embodiments the fixation implant is or resembles a bone screw insofar as such fixation member includes a head and an elongated shank that includes a threaded portion, and in some embodiments, a shank portion that is proximate to the head that is not threaded. It will be appreciated that such fixation members may comprise one or more different thread features that may vary in any one or more number of threads, frequency, pitch, helix angle, thread angle, and major and minor diameters. And the threading may be male (extending away from the fixation implant), female (notches, grooves or channels cut into the fixation implant for receiving male threads), and combinations of these. A thread may be continuous or discontinuous. Further, any one or more of the thread features may be shaped as known in the art, including shapes selected from “V” shaped, square-, buttress-, reverse buttress threaded, and combinations of these, and the thread features may be left or right hand oriented, and the thread features may be self-cutting or self-tapping, or non-self-cutting or non-self-tapping, and combinations of these. Further, the threading may be present only on the shank, or may be present on the shank and one or more of at least a portion of the head and the distal tip. As described variously herein, a fixation member having external threading may alternately be referred to as a screw.

In yet other representative embodiments, the fixation implant is or resembles a bone anchor or plug insofar as such fixation member includes a head and an elongated shank that is only partially threaded. It will be appreciated that in some such embodiments, such fixation members may comprise one or more surface features for enhancing engagement with tissue such as cortical or cancellous bone, such features including but not limited to, keels, fins, and distal bulbs or protuberances. In some embodiments, the fixation implant may have a surface treatment that is suitable for osseo-induction and may be one or more of porous and comprise an osseo-inductive agent, including a biological agent.

In accordance with some embodiments the fixation member has an overall cylindrical, conical, or frusto conical shape that has either a fixed or an increasing diameter from distal to proximal. In some specific embodiments, the head has a frusto conical or a spherical or hemispherical shape. And in some embodiments, the shank has an overall or generally cylindrical shape, with a tapered or conical distal tip. In various embodiments, the fixation member may have a shank that is fully threaded, or it may have a short-unthreaded portion.

As used herein, the term “head” in reference to the proximal head portion of the fixation implant means and includes a structure that is selected from spherical, shaped (e.g., generally spherical with one or more flats), hemi-spherical, frustoconical, discoid, and planar. Thus, in various embodiments with respect to the head, the fixation implant may resemble one of a conventional bone screw, a pedicle screw, a headless screw and other forms, wherein in each instance the head portion of the fixation implant is adapted with at least one feature for facilitating its insertion into bone. In accordance with some embodiments, a fixation member has a head that comprises a flat surface or top and may further comprise an enlarged outer diameter relative to the outer diameter of the shank, wherein the head may include an internal bore with one or more internal engagement features for receiving a driver. Such features may include one or more of a hex configuration for receiving a hex driver, or internal threading for receiving a threaded driver cap, or any of a variety of other possible engagement features. The head and shank of the fixation member, and any threaded driver cap may, in some embodiments, be cannulated for receiving a guide or k-wire there through.

Further still, in some embodiments, the fixation member may be cannulated, in some embodiments only a portion of the fixation member may be cannulated, and in some embodiments the fixation member is not cannulated.

In some such embodiments, the shape of the fixation member may be other than circular in cross section across the elongate axis, and thus the fixation member may have any one of a non-circular shape including ovoid and triangular. In some embodiments, all or only a portion of a fixation member may be circular in cross section and all or other portions of a fixation member may have a cross section that is other than circular, including ovoid and triangular. In some exemplary embodiments, a fixation member may have a frustoconical tip and a proximal adjacent portion that is triangular in cross section such that the tip can be pushed in to a bone hole. Further still, in some embodiments, the fixation member may have the same diameters shared for each of the head, shank and tip.

While various inventive aspects, concepts and features of the general inventive concepts are described and illustrated herein in the context of various exemplary embodiments, these various aspects, concepts and features may be used in many alternative embodiments, either individually or in various combinations and sub-combinations thereof. Unless expressly excluded herein all such combinations and sub-combinations are intended to be within the scope of the general inventive concepts. Still further, while various alternative embodiments as to the various aspects, concepts and features of the inventions (such as alternative materials, structures, configurations, methods, devices and components, alternatives as to form, fit and function, and so on) may be described herein, such descriptions are not intended to be a complete or exhaustive list of available alternative embodiments, whether presently known or later developed.

Those skilled in the art may readily adopt one or more of the inventive aspects, concepts and features into additional embodiments and uses within the scope of the general inventive concepts, even if such embodiments are not expressly disclosed herein. Additionally, even though some features, concepts and aspects of the inventions may be described herein as being a preferred arrangement or method, such description is not intended to suggest that such feature is required or necessary unless expressly so stated. Still further, exemplary or representative values and ranges may be included to assist in understanding the present disclosure; however, such values and ranges are not to be construed in a limiting sense and are intended to be critical values or ranges only if so expressly stated.

Moreover, while various aspects, features and concepts may be expressly identified herein as being inventive or forming part of an invention, such identification is not intended to be exclusive, but rather there may be inventive aspects, concepts and features that are fully described herein without being expressly identified as such or as part of a specific invention. Descriptions of exemplary methods or processes are not limited to inclusion of all steps as being required in all cases, nor is the order that the steps are presented to be construed as required or necessary unless expressly so stated.