Patent Description:
This disclosure relates to intramedullary implant systems and associated surgical methods.

A variety of surgical implants are used to treat bone abnormalities such as fractures and bunions. For example, bone plates and intramedullary nails are commonly employed during orthopedic surgeries to stabilize, fuse, and/or align bones or bone fragments in order to restore functionality to a joint.

Document <CIT> discloses an osteotomy device that includes an attachment plate suitable for being locked to the cortical substance of the bone to be treated, having a first proximal portion suitable for being attached to the inner cortical substance of the metatarsal diaphysis of the bone, a distal portion suitable for being attached to the outer cortical substance, next to the epiphysis of the metatarsus, and a central portion connecting the proximal and distal portions, each one of the proximal and distal portions of the plate being provided with at least one hole and orthopaedic screws to pass therethrough; and a proximal intramedullary support system having a shank with a foam tip extending from the end of the proximal portion of the plate.

Further surgical fixation systems are disclosed in documents <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT> and <CIT>.

Document <CIT> is a prior art document pursuant to Article <NUM>(<NUM>) EPC and discloses an implant that comprises a unitary body including an intramedullary portion connected to an extramedullary portion. The unitary body is configured to attach a first bone section to a second bone section. The intramedullary portion has a first longitudinal axis, and is configured for insertion into the first bone section. The intramedullary portion includes at least one first fastener aperture having an aperture axis oriented obliquely relative to the first longitudinal axis. The extramedullary portion is configured to abut a surface of the second bone section and includes at least one second fastener aperture disposed to transversely receive a bone fastener inserted in the second bone section. The extramedullary portion has a second longitudinal axis offset from, the first longitudinal axis.

The present invention is defined by appended claim <NUM>.

Specific embodiments are set forth in the dependent claims.

This disclosure describes exemplary intramedullary implant systems for performing bone fracture, bone fusion, or osteotomy procedures within joints.

<FIG> schematically illustrates portions of a foot <NUM> of the human musculoskeletal system. A forefoot <NUM> of the foot <NUM> is specifically shown. The forefoot <NUM> includes multiples phalanges <NUM> (i.e., toes) and multiples metatarsals <NUM> located proximal to the phalanges <NUM>. As illustrated, the foot <NUM> includes a bone abnormality <NUM>. In an embodiment, the bone abnormality <NUM> is a hallux valgus abnormality (also referred to as a bunion abnormality) in which there is a medial deviation of the first metatarsal <NUM>-<NUM> and a lateral deviation of the first phalanges <NUM>-<NUM>. If not corrected, the bone abnormality <NUM> can lead to pain and arthritis.

<FIG> illustrate an intramedullary implant system <NUM> according to an embodiment of the invention and for repairing the bone abnormality <NUM> of <FIG>. The intramedullary implant system <NUM> includes an implant <NUM> and a multitude of fixation devices <NUM> (e.g., screws, pegs, etc.). The total number of fixation devices <NUM> utilized within the intramedullary implant system <NUM> is not intended to limit this disclosure.

The implant <NUM> includes a plate portion <NUM> and an intramedullary portion <NUM>. In an embodiment, the plate portion <NUM> and the intramedullary portion <NUM> are integrated to establish a single-piece structure. Stated another way, the implant <NUM> may be a monolithic device without any mechanical attachments for connecting the plate portion <NUM> and the intramedullary portion <NUM> together.

The intramedullary portion <NUM>, which may be configured in the shape of a nail body, may extend along a longitudinal centerline axis A between a proximal portion <NUM> and a distal portion <NUM>. The plate portion <NUM> may include any size and shape. The distal portion <NUM> connects to the plate portion <NUM> of the implant <NUM>, whereas the proximal portion <NUM> is disposed at an opposite end of the intramedullary portion <NUM> from the plate portion <NUM>.

In an embodiment, the plate portion <NUM> is offset from the intramedullary portion <NUM>. For example, the plate portion <NUM> may be laterally offset from the longitudinal centerline axis A of the intramedullary portion. The offset between the plate portion <NUM> and the intramedullary portion <NUM> can be any offset distance within the scope of this disclosure (e.g., <NUM>, <NUM>, <NUM>, <NUM>, etc.).

The plate portion <NUM>, the intramedullary portion <NUM>, or both includes openings for receiving the fixation devices <NUM>. In an embodiment, the plate portion <NUM> includes a first opening 34A for receiving a first fixation device 24A, a second opening 34B for receiving a second fixation device 24B, and a third opening 34C for receiving a third fixation device 24C. The first and second fixation devices 24A and 24B may be locking screws and the third fixation device 24C may be a crossing screw, in an embodiment.

The intramedullary portion <NUM> of the implant <NUM> includes one or more deployable talons <NUM>. The talons <NUM> may be configured as deployable wings, barbs, claws, etc. that extend from the implant <NUM> to enhance the intramedullary boney fixation. According to the invention the talons include barbs, claws, or a combination of barbs and claws. The talons <NUM> may also provide rotational stability once deployed. During removal, the talons <NUM> may be retracted to safely remove the implant <NUM> from the intramedullary canal.

The talons <NUM> are selectively deployed between a first position X and a second positon X' (shown in phantom in <FIG>). In the deployed positon X', the talons <NUM> grip surrounding bone and therefore improve stabilization of the implant <NUM> relative to the bone.

The talons <NUM> may be deployed between the first position X and the second position X' using an external driver (not shown) that is affixed to the implant <NUM> post insertion. In an embodiment, the external driver may engage an end of the intramedullary portion <NUM> of the implant <NUM> that is opposite from the talons <NUM> in order to be affixed to the implant <NUM>. Turning the external driver in a first direction (e.g., clockwise) may deploy the talons <NUM> in a controlled manner. An audible clicking noise may be emitted to signify that the talons <NUM> have fully deployed to the second position X'. During removal, the external driver may be affixed to the implant <NUM> and then rotated in a second direction (e.g., counterclockwise) to retract the talons <NUM> back to the first position X. the implant <NUM> may then be safely removed without damaging the surrounding bone.

The implant <NUM>, including the plate portion <NUM> and the intramedullary portion <NUM>, may be made from any biocompatible material or combinations of biocompatible materials. Exemplary materials include, but are not limited to, titanium, titanium alloys, stainless steel, and thermoplastic materials.

With primary reference to <FIG>, an exemplary surgical method to repair the bone abnormality <NUM> using the intramedullary implant system <NUM> may include the following non-limiting steps. After first exposing the first metatarsal <NUM>-<NUM>, an osteotomy may be performed to divide the first metatarsal <NUM>-<NUM> into a distal segment <NUM> and a proximal segment <NUM>. The distal segment <NUM> is then shifted in a direction toward the second metatarsal <NUM>-<NUM>. Next, a intramedullary passage <NUM> may be drilled into the proximal segment <NUM> of the first metatarsal <NUM>-<NUM>. The intramedullary portion <NUM> of the implant <NUM> may then be inserted into the intramedullary passage <NUM>.

The plate portion <NUM> is then positioned against an external surface of the distal segment <NUM>, and the fixation devices <NUM> may then be inserted through the openings <NUM> of the implant <NUM> and into the distal segment <NUM>, the proximal segment <NUM>, or both. In an embodiment, the third fixation device 24C extends at a transverse angle relative to the longitudinal centerline axis A of the intramedullary portion <NUM>. Finally, the talons <NUM> of the intramedullary portion <NUM> may be deployed in order to enhance fixation and stabilization of the implant <NUM> relative to the first metatarsal <NUM>-<NUM>.

<FIG> illustrate another intramedullary implant system <NUM> according to an embodiment of the invention for repairing a bone abnormality, such as the bone abnormality <NUM> of <FIG>. The intramedullary implant system <NUM> includes an implant <NUM> and a multitude of fixation devices <NUM> (e.g., screws, pegs, etc.).

The implant <NUM> includes a plate portion <NUM> and an integral intramedullary portion <NUM>. In an embodiment, the plate portion <NUM> and the intramedullary portion <NUM> are integrated together as a single-piece structure. The implant <NUM> may be a monolithic device without any mechanical attachments for connecting the plate portion <NUM> and the intramedullary portion <NUM> together.

The implant <NUM> may extend along a centerline axis A. In an embodiment, the centerline axis A is non-linear, and thus, portions of the plate portion <NUM>, the intramedullary portion <NUM>, or both may be curved. The curvature of the implant <NUM> simplifies the ability to effect the metatarsal shift between the distal segment <NUM> and the proximal segment <NUM> of the first metatarsal <NUM>-<NUM> in order to repair the bone abnormality.

The intramedullary portion <NUM> of the implant <NUM> may extend between a proximal portion <NUM> and a distal portion <NUM>. The distal portion <NUM> connects to the plate portion <NUM> of the implant <NUM>, whereas the proximal portion <NUM> is disposed at an opposite end of the intramedullary portion <NUM> from the plate portion <NUM>. Once implanted, the plate portion <NUM> is received against an external surface of the bone and therefore is an "extramedullary" component of the implant <NUM>.

The plate portion <NUM>, the intramedullary portion <NUM>, or both includes openings for receiving the fixation devices <NUM>. In an embodiment, the plate portion includes a first opening 58A for receiving a first fixation device 48A, a second opening 58B for receiving a second fixation device 48B, and a third opening 58C for receiving a third fixation device 48C. The first and second fixation devices 48A and 48B may be locking screws and the third fixation device 48C may be a crossing screw, in an embodiment.

The intramedullary portion <NUM> of the implant <NUM> includes one or more deployable talons <NUM>. The talons <NUM> are selectively deployed between a first position X and a second positon X' (shown in phantom in <FIG>). In the deployed positon X', the talons <NUM> grip surrounding bone and therefore improve stabilization of the implant <NUM> relative to the bone.

<FIG> illustrate another exemplary intramedullary implant system <NUM> for repairing a bone abnormality. The intramedullary implant system <NUM> is similar to the intramedullary implant system <NUM> of <FIG> and includes an implant <NUM> and fixation devices <NUM>. However, in this embodiment, the implant <NUM> of the intramedullary implant system <NUM> lacks talons.

The implant <NUM> may include a plate portion <NUM> and an integral intramedullary portion <NUM>. The intramedullary portion <NUM>, which may be configured in the shape of a nail body, may extend along a longitudinal centerline axis A between a proximal portion <NUM> and a distal portion <NUM>. The plate portion <NUM> may include any size and shape. The distal portion <NUM> connects to the plate portion <NUM> of the implant <NUM>, whereas the proximal portion <NUM> is disposed at an opposite end of the intramedullary portion <NUM> from the plate portion <NUM>. Once implanted, the plate portion <NUM> is received against an external surface of the bone and is therefore an "extramedullary" component of the implant <NUM>.

In an embodiment, the plate portion <NUM> is offset from the intramedullary portion <NUM>. For example, the plate portion <NUM> may be laterally offset from the longitudinal centerline axis A of the intramedullary portion <NUM>. The offset between the plate portion <NUM> and the intramedullary portion <NUM> can be any offset distance within the scope of this disclosure (e.g., <NUM>, <NUM>, <NUM>, <NUM>, etc.).

In an embodiment, the plate portion <NUM> includes a first opening 76A for receiving a first fixation device 66A and a second opening 76B for receiving a second fixation device 66B, and the intramedullary portion <NUM> includes a third opening 76C for receiving a third fixation device 66C. The first and second fixation devices 66A and 66B may be locking screws and the third fixation device 66C may be a crossing screw, in an embodiment. The total numbers of openings and fixation devices of the intramedullary implant system <NUM> are not intended to limit this disclosure.

<FIG>, <FIG> illustrate yet another exemplary intramedullary implant system <NUM> for repairing a bone abnormality. The intramedullary implant system <NUM> may include an implant <NUM> and a multitude of fixation devices <NUM> (e.g., screws, pegs, etc.) for fixating the implant <NUM> relative to bone, such as the first metatarsal <NUM>-<NUM>.

The implant <NUM> of the intramedullary implant system <NUM> may be made from a shape memory material (e.g., material or materials capable of exhibiting superelasticity and/or a temperature-induced shape changes). In a first embodiment, the implant <NUM> is made of a metal alloy, such as Nitinol (NiTi). In another embodiment, the implant <NUM> is made of a polymer, such as an appropriately processed polyether ether ketone (PEEK). By virtue of its material make-up, the implant <NUM> can generate a compressive load in order to realign bones or bone segments at desired positions relative to one another and can maintain the compressive load while healing occurs.

The implant <NUM> may include a plate portion <NUM> and an integral intramedullary portion <NUM>. Once implanted, the plate portion <NUM> is received against an external surface of a bone, such as a distal segment <NUM> of the first metatarsal <NUM>-<NUM>, and is therefore an "extramedullary" component of the implant <NUM>, and the intramedullary portion <NUM> may be inserted within an intramedullary passage <NUM> of a bone, such as a proximal segment <NUM> of the first metatarsal <NUM>-<NUM>.

The implant <NUM> may extend along a centerline axis A. In an embodiment, the centerline axis A is curved. In combination with the shape memory material, the curvature of the implant <NUM> simplifies the ability to effect the metatarsal shift between the distal segment <NUM> and the proximal segment <NUM> of the first metatarsal <NUM>-<NUM> when repairing the bone abnormality.

The plate portion <NUM> may include a first opening 88A for receiving a first fixation device 82A and a second opening 88B for receiving a second fixation device 82B. The first and second fixation devices 82A and 82B may be locking screws, in an embodiment.

The intramedullary portion <NUM> may include a third opening 88C for receiving a third fixation device 82C. The third fixation device 82C may be a crossing screw, in an embodiment. The total numbers of openings and fixation devices of the intramedullary implant system <NUM> are not intended to limit this disclosure.

In another embodiment, the intramedullary portion <NUM> of the implant <NUM> includes a tab <NUM> that protrudes from the intramedullary portion <NUM> near a junction between the intramedullary portion <NUM> and the plate portion <NUM>. The tab <NUM> may function to fill portions of an intramedullary passage <NUM> formed in the proximal segment <NUM> for accommodating the intramedullary portion <NUM>. The third opening 88C may extend through the tab <NUM>. Therefore, once inserted, the third fixation device 82C may be fixated through the tab <NUM>.

<FIG> illustrate an exemplary intramedullary implant system <NUM> for repairing another bone abnormality <NUM> of a bone <NUM>. In this embodiment, the bone abnormality <NUM> includes a fracture. The bone <NUM> may be a humerus or any other long bone. Although shown proximally, the fracture could be located anywhere on the bone <NUM>.

The intramedullary implant system <NUM> may include an intramedullary nail <NUM>, one or more plates <NUM>, one or more washers <NUM>, and a plurality of fixation devices <NUM>. The total numbers of plates <NUM>, washers <NUM>, and fixation devices <NUM> used within the intramedullary implant system <NUM> are not intended to limit this disclosure.

The intramedullary nail <NUM> may include a cannulated body <NUM> that extends along a longitudinal centerline axis A between a proximal portion <NUM> and a distal portion <NUM>. The proximal portion <NUM> may include a first plurality of openings 114A (e.g., holes or slots) for accommodating the fixation devices <NUM>, and the distal portion <NUM> may include a second plurality of openings 114B for accommodating the fixation devices <NUM>. In general, one fixation device <NUM> may be received through each opening 114A, 114B. However, it is not necessary for each opening 114A, 114B to be utilized during a given surgical procedure.

The intramedullary nail <NUM> may embody various configurations. In an embodiment, the cannulated body <NUM> of the intramedullary nail <NUM> is completely straight along the longitudinal axis (see picture (a) of <FIG>). In another embodiment, the proximal portion <NUM> of the cannulated body <NUM> is angled relative to the distal portion <NUM> to establish a slight bend <NUM> in the intramedullary nail <NUM> (see picture (b) of <FIG>). In addition, depending on the size of the bone <NUM>, the intramedullary nail <NUM> could include a small size (see pictures (a) and (b) of <FIG>), a medium size (see picture (c) of <FIG>), or a large size (see picture (d) of <FIG>).

Once implanted in the bone <NUM>, at least a portion of the intramedullary nail <NUM> may extend across a facture line <NUM> of the fracture. In the illustrated embodiment, a portion of the proximal portion <NUM> extends across the fracture line <NUM>. However, this will ultimately depend on the location of the fracture and the type of bone, among other factors.

One or more of the plates <NUM> may be utilized in conjunction with the intramedullary nail <NUM> in order to augment the fracture fixation. The plate <NUM> may include any size or shape (an exemplary plate <NUM> design is shown in <FIG>).

The plate <NUM> may optionally include a groove <NUM> for allowing the bending/molding of the plate <NUM> to sit flush on differing bone anatomies or in differing bone locations. In an embodiment, the groove <NUM> is located on a bone facing surface <NUM> of the plate <NUM>.

The plate <NUM> may additionally include a plurality of openings <NUM> that are configured to receive one of the fixation devices <NUM>. In an embodiment, a fixation device 104A may be received within one of the openings <NUM> of the plate <NUM> and within one of the openings 114A, 114B of the intramedullary nail <NUM>. The fixation devices 104A thereby locks the intramedullary nail <NUM> and the plate <NUM> together. Once locked together, the plate <NUM> can be rotated as desired to better approximate a fractured segment of the bone <NUM> back to its anatomical location. Additional fixation devices 104B and 104C may then be inserted through openings <NUM> of the plate <NUM> and into the bone <NUM> to repair the fracture.

The plate <NUM> may additionally include one or more suture holes <NUM>. The suture holes <NUM> are configured to receive a suture, filament, or some other threadlike material for assisting in repairing the fracture and/or for tying tissue to the bone <NUM>.

One or more of the washers <NUM> may additionally be utilized in conjunction with the intramedullary nail <NUM> in order to further augment the fracture repair. The washer <NUM> may include any size or shape. In a first embodiment, the washer <NUM> is round (see <FIG>). In a second embodiment, the washer <NUM> is rectangular (see <FIG>). Other shapes are also contemplated within the scope of this disclosure.

The washer <NUM> may include a central opening <NUM> that is configured to receive one of the fixation devices <NUM>. In an embodiment, a fixation device 104D may be received within the central opening <NUM> and within one of the openings 114A, 114B of the intramedullary nail <NUM>. The fixation devices 104D thereby locks the intramedullary nail <NUM> and the washer <NUM> together for augmenting the fracture repair.

The washer <NUM> may additionally include one or more suture holes <NUM>. In an embodiment, the suture holes <NUM> surround the central opening <NUM>. The suture holes <NUM> are configured to receive a suture, filament, or some other threadlike material for assisting in repairing the fracture and/or for tying tissue to the bone <NUM>.

An exemplary method for using the intramedullary implant system <NUM> to repair a fractured bone may include the following exemplary method steps. The intramedullary implant system <NUM> can be implanted using percutaneous or open reduction techniques. First, fragments of the fractured bone can be pinned together for initial fixation. The intramedullary nail <NUM> may then be inserted into the bone using a radiolucent attachment which also functions as a guide for insertion of the fixation devices <NUM> and the plates <NUM> and washers <NUM>. Fluoroscopy can be utilized to aid in final reduction of fracture fragments and assurance that the fixation devices <NUM> and plates <NUM>/washers <NUM> are correctly placed to completely reduce the fracture fragments.

The intramedullary implant systems of this disclosure are configured for treating various bone abnormalities. Non-limiting examples of bone abnormalities that may be treated include hallux valgus procedures, bunionectomies, fracture repairs, fusion (i.e., arthrodesis) repairs, etc..

Moreover, the systems described herein have referenced surgery in humans. However, the implants of this disclosure can also be used in arthroplasty surgery in other animals, including but not limited to, dogs, horses, cats, cattle, etc..

Although the different non-limiting embodiments are illustrated as having specific components or steps, the embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from any of the non-limiting embodiments in combination with features or components from any of the other non-limiting embodiments.

It should further be understood that although a particular component arrangement is disclosed and illustrated in these exemplary embodiments, other arrangements could also benefit from the teachings of this disclosure.

Claim 1:
An intramedullary implant system (<NUM>), comprising:
an implant (<NUM>) including a plate portion (<NUM>) and an integral intramedullary portion (<NUM>);
a locking screw (24A, 24B) received through an opening of the plate portion (<NUM>);
a crossing screw (24C) received through an additional opening of the plate portion (<NUM>) or the integral intramedullary portion (<NUM>),
wherein the crossing screw (24C) extends at a non-perpendicular angle relative to a centerline axis (A) of the implant (<NUM>);
characterized in that the system comprises
talons (<NUM>) provided on the integral intramedullary portion (<NUM>) and configured to deploy from a first position (X) to a second position (X') to increase stability of the implant (<NUM>) relative to a bone,
wherein the talons (<NUM>) include barbs, claws, or a combination of barbs and claws.