Patent Description:
Intramedullary rods, also referred to as intramedullary nails or bone nails, are implantable medical devices that are commonly used for fracture stabilization and fixation. Intramedullary rods are often cannulated to allow them to be placed over a wire to guide their positioning and to align bone fragments sought to be stabilized. Rods often include structural features, such as through passageways, to facilitate placement of locking screws used to attach parts of the fractured bone to the nail or to ensure a reliable fixation of the rod in the intramedullary canal.

A targeting device, also referred to as an outrigger, is attached to the intramedullary rod during placement to facilitate precise positioning of locking screws through the accommodating structural features in the rod. The structural interface between the targeting device and the intramedullary rod is critical for the function of the system and achievement of a desired positioning of the rod and associated locking screws. The interface needs to be precise but also must be able to transmit high torsional moments, high bending moments and high impact forces during rod insertion, adjustment and nail removal. This is particularly critical during placement of the intramedullary rod, which often involves use of a hammer to transmit force onto the rod.

Conventional targeting devices attach to the topmost surface of the intramedullary rod to form the structural interface between the targeting device and intramedullary rod. Unfortunately, this structural arrangement places limitations on the design of intramedullary rods.

A need remains, therefore, for improved intramedullary rods, targeting devices for use with the intramedullary rods during orthopedic procedures, intramedullary rod systems, intramedullary rod lots, and methods of placing an intramedullary rod in a bone.

<CIT> describes examples of devices and methods for stabilizing a fracture in a bone including a body having an elongate distal portion having an outer surface defining a screw thread and an elongate proximal portion having a non-threaded outer surface.

The invention is defined in claim <NUM> and preferred features are set out in the dependent claims. Various example intramedullary rods are described below.

An example intramedullary rod comprises a head member haying a first end, a. second end, and a body extending between the first end of die head member and the second end of the head member, the head member formed of a first material and defining a circumferential flange and a circumferential shoulder, the circumferential flange extending radially outwardly from the head member and lying on a plane extending through the longitudinal axis of said intramedullary rod, the circumferential shoulder disposed between the first end of the head member and the circumferential flange; a shaft member extending the head member, the shaft member having a first end, a second end, and a body extending between the first end of the shaft member and the second end of the shaft member; and a head extension partially disposed over the head member and having a first end, a second end, a wall, the head extension formed of a second material that is different than the first material, the second end of the head extension contacting the circumferential shoulder of the head member.

Another example intramedullary rod comprises a head member having a first end, a second end, and a body extending between the first end of the head member and the second end of the head member, the head member formed of a first material and defining a circumferential flange and a circumferential shoulder, the circumferential flange extending radially outwardly from the head member and lying on a plane extending through the longitudinal axis of said intramedullary rod, the circumferential shoulder disposed between the first end of the head member and the circumferential flange; the head member further defining a a first opening, a second opening, and a passageway extending through die head member from the first opening to the second opening; a shaft member extending the head member, the shaft member having a first end, a second end, and a body extending between the first end of the shaft member and the second end of the shaft member; a head extension partially disposed over the head member and having a first end, a second end, a wall, the head extension formed of a second material that is different than the first material, the second end of the head extension contacting the circumferential shoulder of the head member; and an outer body member disposed circumferentially about the shaft member and a portion of the head member, a portion of the outer body member disposed around the first opening of the head member.

Another example intramedullary rod comprises a head member having a first end, a second end, and a body extending between the first end of the head member and the second end of the head member, the head member formed of a first material and defining a circumferential flange and a circumferential shoulder, the circumferential flange extending radially outwardly from the head member and lying on a plane extending through the longitudinal axis of said intramedullary rod, the circumferential shoulder disposed between the first end of the head member and the circumferential flange, the head member further defining a a first opening, a second opening, and a passageway extending through the head member from the first opening to the second opening; a shaft member extending the head member, the shaft member having a first end, a second end, and a body extending between the first end of the shaft member and the second end of the shaft member; a head extension partially disposed over the head member and having a first end, a second end, a wall, the head extension formed of a second material that is different than the first material, the second end of the head extension contacting the circumferential shoulder of the head member; and an outer body member disposed circumferentially about the shaft member and a portion of the head member, a portion of the outer body member disposed around the first opening of the head member. Each of the head member and the shaft member comprises a metal and each of the head extension and outer body member comprises a radiolucent material.

Various example intramedullary rod systems are described.

An example intramedullary rod system comprises an intramedullary rod comprising a head member having a first end, a second end, and a body extending between the first end of the head member and the second end of the head member, the head member formed of a first material and defining a circumferential flange and a circumferential shoulder, the circumferential flange extending radially outwardly from the head member and lying on a plane extending through the longitudinal axis of said intramedullary rod, the circumferential shoulder disposed between the first end of the head member and the circumferential flange; a shaft member extending the head member, the shaft member having a first end, a second end, and a body extending between the first end of the shaft member and die second end of the shaft member; and a head extension partially disposed over the head member and having a first end, a second end, a wall, the head extension formed of a second material that is different than the first material, the second end of the head extension contacting the circumferential shoulder of the head member. The intramedullary rod is removably attached to a targeting device having a terminal rod contacting surface such that the terminal rod contacting surface of the targeting device is in contact interface with the circumferential shoulder of the intramedullary rod.

Various intramedullary rod kits are described.

An example intramedullary rod kit comprises a least one intramedullary rod comprising a head member having a first end, a second end, and a body extending between the first end of the head member and the second end of the head member, the head member formed of a first material and defining a circumferential flange and a circumferential shoulder, the circumferential flange extending radially outwardly from the head member and lying on a plane extending through the longitudinal axis of said intramedullary rod, the circumferential shoulder disposed between the first end of the head member and the circumferential flange; a shaft member extending the head member, the shaft member haying a first end, a second end, and a body extending between the first end of the shaft member and the second end of the shaft member; and a head extension partially disposed oyer the head member and having a first end, a second end, a wall, the head extension formed of a second material that is different than the first material, the second end of the head extension contacting the circumferential shoulder of the head member. The intramedullary rod kit further comprises a targeting device having a terminal rod contacting surface such that the terminal rod contacting surface of the targeting device is in contact interface with the circumferential shoulder of the intramedullary rod.

Various example methods of placing an intramedullary rod in a bone are described. Although the methods are not claimed, the methods may be used with an intramedullary rod according to the claims.

An example method of placing an intramedullary rod according to the claims in a bone comprises removably attaching an intramedullary rod according to an embodiment to a targeting device having a terminal rod contacting surface such that the terminal rod contacting surface of the targeting device is in contact interface with the circumferential shoulder of the intramedullary rod; inserting the intramedullary rod into the intramedullary canal of said bone; applying force to the targeting device such that the force is transferred onto the circumferential shoulder of the intramedullary rod and the intramedullary rod is advanced in the intramedullary canal of said bone; securing the intramedullary rod to said bone; and removing the targeting device from contact interface with the intramedullary rod.

Additional understanding of the intramedullary rods according to the claims, targeting devices which are not within the scope of the claims but that may be used with an intramedullary rod according to the claims, intramedullary rod systems and/or intramedullary rod kits comprising an intramedullary rod according to the claims, and methods which are not within the scope of the claims but may be used to place an intramedullary rod according to the claims in a bone can be obtained by reviewing the detailed description of selected examples, below, with reference to the appended drawings.

The following detailed description and the appended drawings describe and illustrate various example intramedullary rods, targeting devices, intramedullary rod systems, intramedullary rod kits, and methods of placing an intramedullary rod in a bone. The description and illustration of these examples enable one skilled in the art to make and use examples of the inventive intramedullary rods according to the claims, targeting devices which are not within the scope of the claims but may be used with an intramedullary rod according to the claims, intramedullary rod systems and/or intramedullary rod kits comprising an intramedullary rod according to the claims, and to perform examples of the methods which are not within the scope of the claims but may be used to place an intramedullary rod according to the claims in a bone. They do not limit the scope of the claims in any manner.

As used herein, the term "lumen", and grammatically related terms, refers to the inside space of a tubular structure. The term does not require any specific dimensions, relative dimensions, configuration, or regularity.

As used herein, the term "outrigger", and grammatically related terms, refers to a targeting device used with an intramedullary rod in the placement of the intramedullary rod in a bone.

As used herein, the term "circumferential", and grammatically related terms, refers to a structural arrangement of one structure relative to another structure, feature, or property of another structure. The term does not require any specific dimensions, relative dimensions, configuration, or regularity of either structure.

<FIG> illustrate a first example intramedullary rod <NUM>. <FIG> illustrates the first example intramedullary rod <NUM> with an attached cap <NUM>. The intramedullary rod <NUM> has a first end <NUM>, a second end <NUM>, and a body <NUM> extending between the first end <NUM> and the second end <NUM>. A first portion <NUM> of the intramedullary rod <NUM> extends along a first longitudinal axis <NUM>, and a second portion <NUM> of the intramedullary rod <NUM> extends along a second longitudinal axis <NUM>. In the illustrated example, the first <NUM> and second <NUM> longitudinal axes intersect at a non-linear angle <NUM>. The intramedullary rod <NUM> includes a head portion <NUM> that includes the first end <NUM>, a tip portion <NUM> that includes the second end <NUM>, and a shaft portion <NUM> extending between the head portion <NUM> and the tip portion <NUM> and comprising the body <NUM>. Also, the intramedullary rod <NUM> includes a head member <NUM>, a shaft member <NUM> partially disposed within the head member <NUM>, and an outer body member <NUM> disposed circumferentially around the shaft member <NUM> and a portion of the head member <NUM>. A head extension <NUM> is disposed on a portion of the head member <NUM> and extends away from the second end <NUM> of the intramedullary rod <NUM> to the first end <NUM> of the intramedullary rod <NUM>. A device lumen <NUM> extends through the entire axial length of the intramedullary rod <NUM> from a first opening <NUM> defined at the first end <NUM> of the intramedullary rod <NUM> by the head extension <NUM> to a second opening <NUM> defined at the second end <NUM> of the intramedullary rod <NUM> by the shaft member <NUM>, placing the entire device lumen <NUM> in communication with the environment external to the intramedullary rod <NUM>. As such, the intramedullary rod <NUM> is a cannulated rod, allowing it to be passed over a separate member, such as a wire, to facilitate placement and/or positioning during implantation.

The head portion <NUM> provides structure for receiving a bone screw, such as a locking or lag screw commonly used in the stabilization and fixation of bone fractures, such as hip fractures. For example, the head portion <NUM> includes die head member <NUM>, which defines a passageway for receiving a screw, as described in detail below. Also, the head portion <NUM> provides structure for interfacing with a targeting device, such as a targeting device according to an embodiment described herein. For example, the head portion <NUM> includes the head extension <NUM>, which cooperates with the head member <NUM> to interface with a targeting device, as described in detail below. The tip portion <NUM> provides structure for interfacing with the medullary canal of a bone, such as a femur, during placement, as well as structure for receiving distal locking screws commonly used in the stabilization and fixation of bone fractures, such as hip fractures.

The head member <NUM> has a first end <NUM>, a second end <NUM>, and a body <NUM> extending between the first end <NUM> and the second end <NUM>. The first end <NUM> defines a first opening <NUM> and the second end <NUM> defines a second opening <NUM>. As best illustrated in <FIG>, the head member <NUM> defines a head member lumen <NUM> extending between the first opening <NUM> and the second opening <NUM>. In the assembled intramedullary rod <NUM>, the first opening <NUM> provides access to the head member lumen <NUM> from the head extension lumen <NUM> and the second opening <NUM> receives a portion of the shaft member <NUM> in a manner that positions the head member lumen <NUM> in line with the shaft member lumen <NUM> defined by the shaft member <NUM>. In use, the intramedullary rod <NUM> can be passed over a previously-placed wire such that the wire extends through the shaft member <NUM>, the head member lumen <NUM> and, ultimately, through the head extension lumen <NUM> if desired or necessary. In this manner, the intramedullary rod <NUM> can then be advanced over the wire to a desired degree to achieve a desired placement and/or positioning before securing the intramedullary rod <NUM> within the medullary canal.

The first end <NUM> of the head member <NUM> defines a circumferential flange <NUM> that extends radially outwardly from the head member <NUM> and lies on a plane that is orthogonal to the first longitudinal axis <NUM> of the intramedullary rod <NUM>. As best illustrated in <FIG>, the circumferential flange <NUM> defines a stop for cap <NUM> when disposed on the intramedullary rod <NUM> and is disposed a distance <NUM> from the terminal surface <NUM> of the head extension <NUM>, as described in more detail herein. Also, as described in detail below, the circumferential flange <NUM> provides a surface for forming a contact interface with a targeting device. Also as best illustrated in <FIG>, the circumferential flange <NUM> has a radial width <NUM> that is equal to, or substantially the same as, the wall width <NUM> of the cap <NUM>. Also as described in detail below, the radial width <NUM> is equal to, or substantially the same as, a wall width of a rod engaging sleeve (e.g., rod engaging sleeve <NUM>) of a targeting device intended for use with the intramedullary rod <NUM>. The head member <NUM> also defines a circumferential shoulder <NUM> and passageway <NUM> bounded by threaded wall <NUM>. As best illustrated in <FIG>, circumferential shoulder <NUM> is disposed between the first end <NUM> of the head member <NUM> and the circumferential flange <NUM> and is radially inward of the circumferential flange <NUM>. Also as best illustrated in <FIG>, the circumferential shoulder <NUM>, passageway <NUM>, and the threaded wall <NUM> cooperate to provide structure for forming an interface with cap <NUM> and, as described in detail below, with a targeting device intended to be used with intramedullary rod <NUM>.

The second end <NUM> of the head member <NUM> forms an extension <NUM> that defines a cavity <NUM> bounded by a circumferential wall <NUM> and a transverse wall <NUM>. The circumferential wall <NUM> surrounds the second longitudinal axis <NUM> of the intramedullary rod <NUM>. The circumferential wall <NUM> defines structure that facilitates formation of an interface <NUM> between the head member <NUM> and the shaft member <NUM>. The transverse wall <NUM> may also define structure that facilitates such interaction. As such, the circumferential wall <NUM>, the transverse wall <NUM>, and, as a result, the cavity <NUM> may have any suitable configuration and a skilled artisan will be able to select an appropriate configuration for each of these structures in an intramedullary rod according to a particular embodiment based on various considerations, including the configuration and nature of the shaft member included in the intramedullary rod. Examples of suitable configurations include circular, splined, and other configurations. In the illustrated example, the circumferential wall <NUM> is circular and smooth, such that cavity <NUM> has a cylindrical form.

The body <NUM> of the head member <NUM> has an outer surface <NUM> that defines a first opening <NUM> on a first axial side of the body <NUM> and a second opening <NUM> positioned a second, opposite axial side of the body <NUM>. A passageway <NUM> extends from the first opening <NUM> to the second opening <NUM>. As best illustrated in <FIG> and <FIG>, the passageway <NUM> extends along an axis <NUM> that is disposed at a transverse angle to the first longitudinal axis <NUM> of the intramedullary rod <NUM>. The passageway <NUM> is sized and configured to receive a lag screw used for securing the intramedullary rod <NUM> to a bone.

The head extension <NUM> is disposed about the first end <NUM> of the head member <NUM> and includes a wall <NUM> that defines the terminal surface <NUM> on the first end <NUM> of the intramedullary rod <NUM> and a second end <NUM> that interfaces with the circumferential shoulder <NUM>, as described in more detail herein. Also, the head extension <NUM> defines head extension lumen <NUM> that is in communication with the head member lumen <NUM>. As best illustrated in <FIG>, the wall <NUM> of the head extension <NUM> has a wall width <NUM> that is substantially the same as the radial width <NUM> of the circumferential shoulder <NUM> of the head member <NUM>. Each of the head extension <NUM> and the head member <NUM> defines structure that facilitates formation of an interface between the head member <NUM> and the head extension <NUM> such that they are attached to one another (e.g., permanently). As best illustrated in <FIG>, this structural arrangement forms a circumferential interface <NUM> between the head extension <NUM> and the head member <NUM> that is smooth and effectively seamless. In alternative embodiments, a head extension <NUM> can be conical (e.g., include a taper between about <NUM> degree and about <NUM> degrees).

The head member <NUM> is advantageously formed of a metal. As such, the head member <NUM>, and specifically the circumferential flange <NUM>, provides a surface suitable for receiving a force, such as a hammering force transmitted to the head member <NUM> while the intramedullary rod is attached to a targeting device, as described in detail below. Examples of suitable metals for the head member <NUM> include, but are not limited to, Titanium, Magnesium, and other metals. Importantly, by placing the circumferential flange <NUM> away from the terminal surface <NUM> of die first end <NUM> of the intramedullary rod <NUM>, the head extension <NUM> need not be adapted for receiving such force. As a result, the head extension <NUM> can be formed of materials that are relatively weaker than the material of die head member <NUM>. This can be advantageous, and is indeed preferred, as it allows the head extension <NUM> to be formed of a material that provides other performance characteristics to the first end <NUM> of the intramedullary rod. For example, the head extension <NUM> can be formed of a radiolucent material, which may be beneficial when evaluating positioning of the intramedullary rod <NUM> during placement in a bone. Examples of suitable radiolucent materials include, but are not limited to, polyether ether ketone (PEEK), carbon fiber reinforced polymers, and other polymeric materials.

The shaft member <NUM> has a first end <NUM>, a second end <NUM>, and a body <NUM> extending between the first end <NUM> and the second end <NUM>. The shaft member <NUM> defines a shaft member lumen <NUM> that extends from the first end <NUM> to the second end <NUM>. Thus, the shaft member <NUM> is a tubular member. In the assembled intramedullary rod <NUM>, the first end <NUM> is disposed within the cavity <NUM> of the head member <NUM> in a manner that places the shaft member lumen <NUM> in communication with the head member lumen <NUM> defined by the head member <NUM>.

The shaft member <NUM> has an outer surface <NUM>. As described in detail below, the outer body member <NUM> circumferentially surrounds the shaft member <NUM> and is in contact with the outer surface <NUM>. The outer surface <NUM> can be treated in a manner that prepares die shaft member <NUM><NUM> for bonding, contact, or other interface with the outer body member <NUM>. If a surface treatment is included, any suitable surface treatment can be used and a skilled artisan will be able to select a suitable surface treatment for an intramedullary rod according to a particular embodiment based on various considerations, such as the materials of the head member and shaft member of the intramedullary rod. Examples of suitable surface treatments include roughening, etching, and other surface treatments. Also, the portion of the outer surface on the first end of the shaft member can be left untreated or treated in a different manner than the remainder of the shaft member in an intramedullary rod according to a particular embodiment if desirable or necessary, such as to facilitate formation of a head-shaft assembly.

In the illustrated embodiment, the shaft member <NUM> is a separate member that extends from the head member <NUM> and that is partially disposed within the head member <NUM>. It is noted, though, that, in some embodiments, the shaft member and the head member can be formed as a single structural member. In these embodiments, die head member and shaft member each define structural portions of a single structural member. It is noted, though, that the inclusion of separate members is considered advantageous at least because it imparts modularity onto the intramedullary rod, which provides an opportunity to realize efficiencies in the manufacturing of many intramedullary rods, particularly when manufacturing intramedullary rods according to multiple embodiments having shaft members with different axial lengths but similar head members, such as the intramedullary rod <NUM> illustrated in <FIG> and die intramedullary rod <NUM> illustrated in <FIG>.

The outer body member <NUM> is a tubular member disposed circumferentially around die shaft member <NUM> and extension <NUM> of the head member <NUM>. Similar to the head extension <NUM>, the outer body member <NUM> can be formed of materials that are relatively weaker than the material of the head member <NUM>. Indeed, it is considered advantageous to form the outer body member <NUM> of the same material as die head extension. Thus, the outer body member <NUM> can be formed of a radiolucent material, such as polyether ether ketone (PEEK), carbon fiber reinforced polymers, and other polymeric materials. It is noted, though, that the outer body member <NUM> can be formed of a material that is different than the material of the head extension <NUM>.

Each of the shaft member and outer body member in an intramedullary rod according to an embodiment can have any suitable configuration and a skilled artisan will be able to select an appropriate configuration for each of these elements for a particular embodiment based on various considerations, including the nature of the medullary canal of the bone or bone type with which the intramedullary rod is intended to be used. Each of the shaft member and outer body member in an intramedullary rod according to an embodiment can have any outer diameter. Furthermore, the shaft member and outer body member in an intramedullary rod according to an embodiment can have any suitable relative outer diameters. A skilled artisan will be able to select suitable outer diameters, and relative outer diameters, for the shaft member and outer body member in an intramedullary rod according to a particular embodiment based on various considerations, including the nature of the bone with which the intramedullary rod is intended to be used, the nature of the materials used for the shaft member and the outer body member, and other considerations. The outer diameters, and relative outer diameters, illustrated herein provide examples of outer diameters and relative outer diameters considered suitable for intramedullary rods. An intramedullary rod can be configured to be positioned within any suitable portion of a body. For example, the intramedullary rods described herein can comprise a hip fracture intramedullary rod, a proximal tibia intramedullary rod, a proximal humeral intramedullary rod, a humeral intramedullary rod, a proximal femur intramedullary rod, distal femur intramedullary rod, TTC intramedullary rod, and any other intramedullary rod considered suitable for a particular embodiment.

In the illustrated embodiment, the intramedullary rod <NUM> defines a locking screw passageway <NUM> that extends from one side of the intramedullary rod <NUM> to the opposite side of the intramedullary rod <NUM>. The locking screw passageway <NUM> is sized and configured for receiving a locking screw commonly used in the stabilization and fixation of bone fractures, such as hip fractures. While optional, inclusion of locking screw passageways is considered advantageous to facilitate securement of the intramedullary rod <NUM> to bone during placement. Also, any suitable number of locking screw passageways can be included in an intramedullary rod according to a particular embodiment and a skilled artisan will be able to select an appropriate number of locking screw passageways for a particular embodiment based on various considerations, including any number of locking screws considered desirable or potentially necessary for use of the intramedullary rod in stabilization and/or fixation of a particular bone fractures. Furthermore, while the illustrated locking screw passageway <NUM> is positioned such that it extends through the head member <NUM>, a locking screw passageway in an intramedullary rod according to a particular embodiment can be located at any suitable position along the length of the intramedullary rod.

<FIG> illustrates a cap <NUM> suitable for use with intramedullary rod <NUM>. While the cap <NUM> is optional, it is considered advantageous as it provides a continuous outer surface, effectively eliminating the circumferential shoulder <NUM> from the outer profile of the intramedullary rod <NUM>. As such, the cap <NUM> can be installed onto the head extension <NUM> after the intramedullary rod <NUM> has been placed in a bone. That is, the cap <NUM> can be installed onto the head extension <NUM> after the circumferential shoulder <NUM> has been used to accept a force from a targeting device during placement of the intramedullary rod <NUM>. After placement, the circumferential shoulder <NUM> still defines a step on the outer surface of the intramedullary rod <NUM> and, if this is undesirable for any reason, the cap <NUM> can be installed to eliminate the step.

The cap <NUM> includes a circumferential wall <NUM> and an end wall <NUM> that cooperatively define an interior chamber <NUM>. A projection <NUM> extends from the inner surface of the end wall <NUM> into the interior chamber <NUM>. The projection <NUM> defines an outer threaded surface <NUM> configured to matingly engage with threaded wall <NUM> of head member <NUM>. A cap passageway <NUM> extends through the cap <NUM> and, as best illustrated in <FIG>, is continuous with passageway <NUM>. The circumferential wall <NUM> has a wall thickness <NUM> that is equal to the radial width of the circumferential flange <NUM> of the head member <NUM>.

If included, cap <NUM> can be formed of any suitable material, including metals and non-metals. It is considered advantageous to form the cap of the same material from which the head extension <NUM> is formed as this effectively preserves the advantages provided by the head extension <NUM> when the cap <NUM> is installed. As a result, the cap <NUM> can be formed of materials that are relatively weaker than the material of the head member <NUM>, including radiolucent materials such as, polyether ether ketone (PEEK), carbon fiber reinforced polymers, and other polymeric materials.

<FIG> illustrates intramedullary rod <NUM> illustrated in <FIG> with the cap <NUM> illustrated in <FIG> and a cannulated set screw <NUM>, along with a lag screw <NUM>, an anti-rotation pin <NUM>, and a locking screw <NUM> in interface with the intramedullary rod <NUM>.

As best illustrated in <FIG>, the outer body member <NUM> in the illustrated embodiment is extends around the first opening <NUM> on the body <NUM> of the head member <NUM>. This placement of the outer body member <NUM> protects the intramedullary rod <NUM> from damage the could be imparted on the intramedullary rod <NUM> during placement of a lag screw, either by interaction with the lag screw or with an accessory used in placement of the lag screw, such as a drill.

<FIG> illustrates another intramedullary rod <NUM>. The intramedullary rod <NUM> is similar to the intramedullary rod <NUM> described above and illustrated in <FIG>, and <FIG>, except as detailed below. Thus, the intramedullary rod <NUM> has a first end <NUM>, a second end <NUM>, and a body <NUM> extending between the first end <NUM> and the second end <NUM>. The intramedullary rod <NUM> includes a head portion <NUM> that includes the first end <NUM>, a tip portion <NUM> that includes the second end <NUM>, and a shaft portion <NUM> extending between the head portion <NUM> and the tip portion <NUM> and comprising the body <NUM>. Also, the in tramedullary rod <NUM> includes a head member <NUM>, a shaft member <NUM> partially disposed within the head member <NUM>, an outer body member <NUM> disposed circumferentially around the shaft member <NUM> and a portion of the head member <NUM>, and a head extension <NUM> disposed on a portion of the head member <NUM> and extending away from the second end <NUM> of the intramedullary rod <NUM> to the first end <NUM> of the intramedullary rod <NUM>.

In the illustrated embodiment, the shaft member <NUM> has an axial length that is greater than the axial length of the shaft member <NUM> illustrated in <FIG>, and <FIG>. In addition, the shaft member <NUM> and the outer body member <NUM> cooperatively define two passageways <NUM>, <NUM> between the first end <NUM> and the second end <NUM> of the shaft member <NUM>. Each of die passageways <NUM>, <NUM> extends along an axis that is disposed at a transverse angle to the second longitudinal axis <NUM> of the intramedullary rod <NUM>. Each of the passageways <NUM>, <NUM> is sized and configured to receive a lag screw used for securing the intramedullary rod <NUM> to a bone. In the illustrated embodiment, the second passageway <NUM> is elongated and has a length along die second longitudinal axis <NUM> that is greater than the length of the first passageway <NUM> along the second longitudinal axis <NUM>.

A shaft member included in an intramedullary rod can have any suitable axial length and selection of a suitable axial length can be based on various considerations, including the intended use of the intramedullary rod. Examples of axial lengths considered suitable for a shaft member include lengths that are equal to, greater than, less than, or about the axial length of a head member, axial lengths that are two times the axial length of a head member, axial lengths that are three times the axial length of a head member, axial lengths that are four times the axial length of a head member, axial lengths that are greater than four times the axial length of a head member, and any other length considered suitable for a particular embodiment. While intramedullary rod <NUM> has been illustrated as defining two passageways <NUM>, <NUM> between the first end <NUM> and die second end <NUM> of the shaft member <NUM>, an intramedullary rod can define any suitable number of passageways between a first end and a second end of a shaft member and each passageway can have any suitable configuration. Examples of numbers of passageways considered suitable for an intramedullary rod to define include one, more than one, two, a plurality, three, four, five, and any other number considered suitable for a particular embodiment.

<FIG> illustrates an example targeting device <NUM>. <FIG> and <FIG> illustrate the targeting device <NUM> illustrated in <FIG> attached to an intramedullary rod <NUM> creating an intramedullary rod system <NUM>. The intramedullary rod <NUM> is similar to the intramedullary rod <NUM> described above and illustrated in <FIG>, and <FIG>, except as detailed below. The targeting device <NUM> has a first end <NUM>, a second end <NUM>, and a body <NUM> extending between the first end <NUM> and the second end <NUM>. The targeting device <NUM> includes a rod engaging member <NUM> that includes the first end <NUM> and a handle <NUM> that includes the second end <NUM>.

The rod engaging member <NUM> has a first end <NUM>, a second end <NUM>, and a body <NUM> that extends from the first end <NUM> to the second end <NUM>. The rod engaging member <NUM> defines structure on the first end <NUM> that interfaces with the handle <NUM> such that attachment to the handle <NUM> can be accomplished. The rod engaging member <NUM> defines a rod engaging sleeve <NUM> that has a rod engaging lumen <NUM>. The rod engaging sleeve <NUM> has a first end <NUM>, a second end <NUM>, a first portion <NUM>, a second portion <NUM>, and a third portion <NUM>. The first portion <NUM> extends from the first end <NUM> toward the second end <NUM> and has a first wall width <NUM>. The second portion <NUM> is disposed between the first and third portions <NUM>, <NUM> and has a second wall width <NUM>. The third portion <NUM> extends from the second portion <NUM> to the second end <NUM> and has a third wall width <NUM>. The first wall width <NUM> and the third wall width <NUM> are each less than the second wall width <NUM>. The third wall width <NUM> is equal to, or substantially the same as, the radial width <NUM> the circumferential flange <NUM>. The rod engaging sleeve <NUM> provides structure for interfacing with an intramedullary rod, such as an intramedullary rod according to an embodiment described herein. For example, the rod engaging sleeve <NUM> defines a second end <NUM>, which cooperates with a head extension and a head member of an intramedullary rod to interface with an intramedullary rod, as described in detail below.

The rod engaging lumen <NUM> extends from a first opening <NUM> defined between the first and second ends <NUM>, <NUM> of the rod engaging member <NUM> to a second opening <NUM> defined on the second end <NUM> of the rod engaging member <NUM>. The rod engaging member lumen <NUM> extends along an axis <NUM> that extends through each of the first opening <NUM> and the second opening <NUM>. The rod engaging lumen <NUM> has a first portion <NUM>, a second portion <NUM>, and a third portion <NUM>. The first portion <NUM> has a first inside diameter <NUM>, the second portion <NUM> has a second inside diameter <NUM>, and the third portion <NUM> has a third inside diameter <NUM>. The second inside diameter <NUM> is less than the first inside diameter <NUM> and the third inside diameter <NUM> such that a first shoulder <NUM> and a second shoulder <NUM> are defined within the rod engaging lumen <NUM>.

As shown in <FIG>, the first end <NUM> of die head member <NUM> is disposed within the rod engaging lumen <NUM> when the intramedullary rod <NUM> is attached to the targeting device <NUM> such that the rod engaging lumen <NUM> is in line with the head member lumen <NUM>. In use, the rod engaging member <NUM> and the intramedullary rod <NUM> can be passed over a previously-placed wire such that the wire extends through the rod engaging lumen <NUM>, die shaft member <NUM>, the head member lumen <NUM> and, ultimately, through the head extension lumen <NUM> if desired or necessary. In this manner, the targeting device <NUM> and the intramedullary rod <NUM> can then be advanced over the wire to a desired degree to achieve a desired placement and/or positioning before securing the intramedullary rod <NUM> within the medullary canal.

The second shoulder <NUM> is positioned a distance <NUM> from the second end <NUM> that is greater than the distance <NUM> from the terminal surface <NUM> of the head extension <NUM> and the circumferential flange <NUM> such that when the intramedullary rod <NUM> is disposed within the targeting device <NUM> the terminal surface <NUM> of the head extension <NUM> does not contact the second shoulder <NUM>. Rather, the rod engaging member <NUM> provides a surface for forming a contact interface with an intramedullary rod. As shown in <FIG>, the second end <NUM> of the rod engaging sleeve <NUM> contacts the circumferential flange <NUM> of the head member <NUM> such that the terminal end <NUM> of the of the head extension <NUM> is disposed within the rod engaging lumen <NUM>. The rod engaging member <NUM> is advantageously formed of a metal (e.g., titanium). As such, the rod engaging member <NUM>, and specifically the rod engaging sleeve <NUM>, provides a surface (e.g., second end <NUM> of the rod engaging sleeve <NUM>) suitable for transferring a force, such as a hammering force, to the head member <NUM> (e.g., circumferential flange <NUM>) while the intramedullary rod <NUM> is attached to the targeting device <NUM>. The interaction between the rod engaging sleeve <NUM> and the circumferential flange <NUM> prevents contact between the terminal surface <NUM> of the head extension <NUM> and the rod engaging member <NUM>.

As shown in <FIG> and <FIG>, the rod engaging member <NUM> defines a plurality of projections <NUM> that extend from the second end <NUM> of tire rod engaging member <NUM> and away from the first end <NUM> of the rod engaging member <NUM>. Each projection of the plurality of projections <NUM> defines structure that interfaces with a recess of a plurality of recesses <NUM> defined by the head member <NUM> disposed within the targeting device <NUM> to provide rotational strength between the targeting device <NUM> and the intramedullary rod <NUM>.

While the rod engaging member <NUM> has been illustrated as defining a rod engaging lumen <NUM>, alternative rod engaging members can define a recess that extends from the second end of the rod engaging member toward the first end of the rod engaging member to a recess base and that includes structure similar to the second portion <NUM> and/or third portion <NUM> of the rod engaging member lumen <NUM> illustrated herein.

The handle <NUM> has a first end <NUM>, a second end <NUM>, and a body <NUM> that extends from the first end <NUM> to the second end <NUM>. The handle <NUM> defines structure on the first end <NUM> that interfaces with the rod engaging member <NUM> such that attachment to the rod engaging member <NUM> can be accomplished. The handle <NUM> also defines a first passageway <NUM> and a second passageway <NUM>. The first passageway <NUM> extends from a first opening <NUM> to a second opening <NUM> and die second passageway <NUM> extends from a first opening <NUM> to a second opening <NUM>. As best illustrated in <FIG>, when die intramedullary rod <NUM> is attached to die targeting device <NUM>, the first passageway <NUM> extends along an axis <NUM> that is disposed at a transverse angle to the longitudinal axis <NUM> of the handle <NUM> and is coaxial with the axis <NUM> that extends through passageway <NUM> defined by the head member <NUM>. The first passageway <NUM> is sized and configured to assist with positioning a lag screw through passageway <NUM> that is used for securing the intramedullary rod <NUM> to a bone. As best illustrated in <FIG>, the second passageway <NUM> extends along an axis <NUM> that is disposed at a transverse angle to the longitudinal axis <NUM> of the handle <NUM> and is coaxial with the axis that extends through the locking screw passageway <NUM> defined by the head member <NUM>. The second passageway <NUM> is sized and configured to assist with positioning a locking screw through locking screw passageway <NUM>.

While intramedullary rod system <NUM> has been illustrated as including targeting system <NUM> and intramedullary rod <NUM>, an intramedullary rod system can include any suitable targeting system and intramedullary rod. Selection of a suitable targeting system and intramedullary rod to include in an intramedullary rod system can be based on various considerations, including the intended use of the intramedullary rod system.

<FIG> illustrates a schematic representation of an example intramedullary rod kit <NUM>. The intramedullary rod kit <NUM> includes a first intramedullary rod <NUM> according to an embodiment, a second intramedullary rod <NUM> according to an embodiment, a third intramedullary rod <NUM> according to an embodiment, a first cap <NUM> according to an embodiment, a second cap <NUM> according to an embodiment, a third cap <NUM> according to an embodiment, and a targeting device <NUM> according to an embodiment. In this example, the intramedullary rod kit <NUM> also includes a first cannulated set screw <NUM>, a second cannulated set screw <NUM>, and a third cannulated set screw <NUM>.

Any suitable intramedullary rod, cap, and targeting device can be included in a kit and selection of a suitable intramedullary rod, cap, and targeting device to include in a kit can be based on various considerations, including the procedure intended to be performed using the kit. Examples of intramedullary rods considered suitable to include in a kit include intramedullary rod <NUM>, intramedullary rod <NUM>, intramedullary rod <NUM>, variations of the intramedullary rods described herein, and any other intramedullary rod according to an embodiment. Examples of caps considered suitable to include in a kit include cap <NUM>, variations of the caps described herein, and any other cap according to an embodiment. Examples of targeting devices considered suitable to include in a kit include targeting device <NUM>, variations of the targeting devices described herein, and any other targeting device according to an embodiment. Optionally, a kit can include an intramedullary system, such as intramedullary system <NUM>. In the illustrated embodiment, the kit <NUM> includes intramedullary rod <NUM>, as shown in <FIG>, and <FIG>, intramedullary rod <NUM>, as shown in <FIG>, intramedullary rod <NUM>, as shown in <FIG> and <FIG>, three caps <NUM>, as shown in <FIG>, and targeting device <NUM>, as shown in <FIG>, <FIG>, and <FIG>.

While the kit <NUM> has been illustrated as including three intramedullary rods <NUM>, <NUM>, <NUM>, three caps <NUM>, <NUM>, <NUM>, and a single targeting device <NUM>, any suitable number, and type, of intramedullary rods, caps, and/or targeting devices can be included in a kit, such as those described herein. Selection of a suitable number of intramedullary rods, caps, and/or targeting devices to include in a kit according to a particular embodiment can be based on various considerations, such as the type of procedure intended to be accomplished using the kit. Examples of suitable numbers of intramedullary rods, caps, and/or targeting devices to include in a kit include at least one, one, two, a plurality, three, four and any other number considered suitable for a particular embodiment.

While the kit <NUM> has been illustrated as including only three intramedullary rods <NUM>, <NUM>, <NUM>, three caps <NUM>, <NUM>, <NUM>, and a single targeting device <NUM>, a kit can include any suitable number of optional components. Examples of numbers of optional components considered suitable to include in a kit include one, at least one, two, a plurality, three, four, five, more than five, and any other number considered suitable for a particular embodiment. Examples of optional components considered suitable to include in a kit include wires for guiding an intramedullary rod and/or targeting device to a point of treatment, lag screws, anti-rotation pins, locking screws, intramedullary rod systems, and/or any other component considered suitable for a particular embodiment.

<FIG> is a flowchart representation of an example method <NUM> of placing an intramedullary rod according to the claims in a bone; although the method is not claimed, the method may be used with an intramedullary rod according to the claims.

A step <NUM> comprises inserting a wire into a medullary canal. Another step <NUM> comprises reaming the medullary canal. Another step <NUM> comprises inserting a portion of an intramedullary rod into a targeting device. Another step <NUM> comprises advancing the intramedullary rod over the wire until a portion of the intramedullary rod is disposed within the medullary canal. Another step <NUM> comprises applying a force on the intramedullary rod directed toward the medullary canal such that the intramedullary rod is advanced into the medullary canal. Another step <NUM> comprises inserting a screw through the intramedullary rod. Another step <NUM> comprises removing the targeting device from the intramedullary rod. Another step <NUM> comprises inserting a portion of the intramedullary rod into a cap. Another step <NUM> comprises attaching the cap to the intramedullary rod.

Step <NUM> can be accomplished using any suitable wire and by applying a force on the wire directed toward the medullary canal. Optionally, step <NUM> can be omitted from method <NUM>.

Step <NUM> can be accomplished using any suitable device and by applying a force on the device directed toward the medullary canal until the device is positioned on the wire and advanced into the medullary canal. Subsequently, the device can be utilized to ream the medullary canal. Optionally, step <NUM> can be omitted from method <NUM>.

Step <NUM> can be accomplished by inserting the head extension of an intramedullary rod into a targeting device until the second end of the rod engaging sleeve contacts the circumferential flange (e.g., circumferential flange <NUM>) defined by the head member. This can be accomplished by applying a force on an intramedullary rod directed toward a targeting device while maintaining the position of the targeting device, or applying a second force on the targeting device directed toward the intramedullary rod. Alternatively, step <NUM> can be accomplished by applying a force on a targeting device directed toward the intramedullary rod while maintaining the position of the intramedullary rod.

Step <NUM> can be accomplished by applying a force on the intramedullary rod and/or targeting device directed toward the medullary canal until a portion of the intramedullary rod is disposed within the medullary canal.

Step <NUM> can be accomplished using any suitable technique or method of applying a force on an intramedullary rod, such as using conventional hammer.

Step <NUM> can be accomplished using the targeting device to position a screw (e.g., lag screw) through a passageway (e.g., passageway <NUM>) defined by the intramedullary rod such that the intramedullary rod is attached to a bone.

Step <NUM> can be accomplished by applying a force on the targeting device directed away from die intramedullary rod until the targeting device is free of the intramedullary rod.

Step <NUM> can be accomplished by inserting the head extension of an intramedullary rod into a cap until the second end of the cap contacts the circumferential flange (e.g., circumferential flange <NUM>) defined by the head member. This can be accomplished by applying a force on a cap directed toward an intramedullary rod while maintaining the position of the intramedullary rod, or applying a second force on the intramedullary rod directed toward the cap.

Step <NUM> can be accomplished using any suitable technique or method of attaching a cap to an intramedullary rod, such as by applying a rotational force on the cap such that the threads defined by the cap interface with the threads defined by the head member of the intramedullary rod.

A head member, a shaft member, a targeting member, and portions thereof, can be made of any material suitable for use in medical devices intended for orthopedic use, including use as a long-term implant. Examples of suitable materials include metals, metal alloys, and polymeric materials. Examples of suitable metals include, but are not limited to, Titanium, Magnesium, and other metals. Examples of suitable metal alloys include, but are not limited to, Ti6A14V, <NUM> LVM, i. 4441Ti-13Nb-13Zr, Ti-12Mo-6Zr-2Fe, Ti-15Mo-5¾>3Al, Ti-15Mo, Ti-35Nb- 7Zr-5Ta andT^29Nb-13Ta4,6Zr Tir6Al-7Nb and Ti- 15Sn4Nb-2Ta-<NUM>. 2Pd Co- Cr-Mo alloys. Examples of suitable polymeric materials include, but are not limited to, polyaryletherketone (PAEK), polyether ether ketone (PEEK), PEEK (<NUM>, <NUM>, <NUM>, <NUM>), Polyamid, PA66, carbon fiber reinforced polyaryletherketone (GFR PAEK), polyether ketone ketone (PEKK), carbon fiber reinforced polyether ketone ketone (CFR PEKK), carbon fiber reinforced polyether ether ketone (CFR PEEK), CFR PEEK (<NUM> CA30, <NUM> CA20, <NUM> CA30, <NUM> CA20 , <NUM> CF20, IS GF3Q, <NUM> CF30, <NUM> GF20), Polyamid GFR, and PA66 GFR.

Claim 1:
An intramedullary rod (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) having a longitudinal axis (<NUM>), the intramedullary rod comprising:
a head member (<NUM>, <NUM>, <NUM>) having a first end (<NUM>, <NUM>), a second end (<NUM>), and a body (<NUM>) extending between the first end (<NUM>) of the head member and the second end (<NUM>) of the head member, the head member (<NUM>, <NUM>, <NUM>) formed of a first material and defining a circumferential flange (<NUM>, <NUM>) and a circumferential shoulder (<NUM>), the circumferential flange (<NUM>, <NUM>) extending radially outwardly from the head member (<NUM>, <NUM>, <NUM>) and lying on a plane extending through the longitudinal axis (<NUM>) of said intramedullary rod, the circumferential shoulder (<NUM>) disposed between the first end (<NUM>) of the head member and the circumferential flange (<NUM>, <NUM>), and wherein the circumferential shoulder (<NUM>) is radially inward of the circumferential flange (<NUM>, <NUM>);
a shaft member (<NUM>, <NUM>, <NUM>) extending the head member (<NUM>, <NUM>, <NUM>), the shaft member having a first end (<NUM>, <NUM>), a second end (<NUM>, <NUM>), and a body (<NUM>) extending between the first end of the shaft member and the second end of the shaft member; and
a head extension (<NUM>, <NUM>, <NUM>) partially disposed over the head member (<NUM>, <NUM>, <NUM>) and having a first end (<NUM>, <NUM>), a second end (<NUM>), a wall (<NUM>), the head extension formed of a second material that is different than the first material, the second end (<NUM>) of the head extension contacting the circumferential shoulder (<NUM>) of the head member (<NUM>, <NUM>, <NUM>).