# Patent

## Title
Systems and methods for internal bone fixation

## Abstract

Internal bone fixation devices and methods for using the devices for repairing a weakened or fractured bone are disclosed herein. A device for use in repairing a fractured bone includes a delivery catheter having an elongated shaft with a proximal end, a distal end, and a longitudinal axis therebetween, wherein the delivery catheter has an inner void for passage of at least one reinforcing material and an inner lumen for passage of a light source; a conformable member releasably engaging the distal end of the delivery catheter, wherein the conformable member moves from a deflated state to an inflated state when the at least one reinforcing material is delivered to the conformable member; and an adapter releasably engaging the proximal end of the delivery catheter for receiving the light source and the at least one reinforcing material.

## Background
RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 11/903,123, filed on Sep. 20, 2007 now U.S. Pat. No. 7811284, which claims the benefit of U.S. Provisional Application Ser. No. 60/858,202, filed Nov. 10, 2006 and U.S. Provisional Application Ser. No. 60/880,646, filed Jan. 16, 2007, and the entirety of these applications are hereby incorporated herein by reference for the teachings therein.


FIELD
The embodiments disclosed herein relate to medical devices for use in repairing a weakened or fractured bone, and more particularly to internal bone fixation devices and methods of using these devices for repairing a weakened or fractured bone.
BACKGROUND
Fracture repair is the process of rejoining and realigning the ends of broken bones. Fracture repair is required when there is a need for restoration of the normal position and function of the broken bone. Throughout the stages of fracture healing, the bones must be held firmly in the correct position and supported until it is strong enough to bear weight. In the event the fracture is not properly repaired, malalignment of the bone may occur, resulting in possible physical dysfunction of the bone or joint of that region of the body.
Until the last century, physicians relied on casts and splints to support the bone from outside the body (external fixation). However, the development of sterile surgery reduced the risk of infection so that doctors could work directly with the bone and could implant materials in the body. Currently there are several internal approaches to repair, strengthen and support a fractured bone. They include the use of internal fixation devices, such as wires, plates, rods, pins, nails, and screws to support the bone directly, and the addition of bone cement mixtures, or bone void fillers to a fractured bone.
The addition of bone cements to a fractured bone for repairing bone and, for example, joining bones are well known in the art. Conventional bone cement injection devices have difficulty adjusting or controlling the injection volume or injection rate of the bone cement in real time in reaction to cancellous bone volume and density conditions encountered inside the fractured bone. Conventional bone cements also may cause complications that include the leakage of the bone cement to an area outside of the fractured bone site, which can result in soft tissue damage as well as nerve root pain and compression.
Thus, there is a need in the art for internal bone fixation devices that repair, strengthen and support a fractured bone using minimally invasive techniques, with ease of use, and minimal damage to the bone and supporting tissues.
SUMMARY
Internal bone fixation devices and methods for using the devices for repairing a weakened or fractured bone are disclosed herein. According to aspects illustrated herein, there is provided an internal bone fixation device that includes a conformable member; and at least one reinforcing material contained within the conformable member, wherein the conformable member moves from a deflated state to an inflated state when the at least one reinforcing material is added to the conformable member.
According to aspects illustrated herein, there is provided a device for use in repairing a fractured bone that includes a delivery catheter having an elongated shaft with a proximal end, a distal end, and a longitudinal axis therebetween, wherein the delivery catheter has an inner void for passage of at least one reinforcing material and an inner lumen for passage of a light source; a conformable member releasably engaging the distal end of the delivery catheter, wherein the conformable member moves from a deflated state to an inflated state when the at least one reinforcing material is delivered to the conformable member; and an adapter releasably engaging the proximal end of the delivery catheter for receiving the light source and the at least one reinforcing material.
According to aspects illustrated herein, there is provided a method for repairing a fractured bone that includes gaining access to an inner cavity of the fractured bone; providing a device for use in repairing the fractured bone, the device comprising a conformable member releasably engaging a delivery catheter, wherein the delivery catheter has an inner void for passage of at least one reinforcing material to the conformable member and an inner lumen for passage of a light source to the conformable member; positioning the conformable member spanning at least two bone segments of the fractured bone; inserting a light source into the inner lumen of the device; adding at least one reinforcing material to the inner void of the device; infusing the at least one reinforcing material through the inner void of the delivery catheter to the conformable member, wherein the conformable member moves from an initial deflated state to a final inflated state; activating the light source to harden the at least one reinforcing material in the inflated conformable member; and releasing the hardened conformable member from the delivery catheter.



BRIEF DESCRIPTION OF THE DRAWINGS
The presently disclosed embodiments will be further explained with reference to the attached drawings, wherein like structures are referred to by like numerals throughout the several views. The drawings shown are not necessarily to scale, with emphasis instead generally being placed upon illustrating the principles of the presently disclosed embodiments.
FIG. 1 shows a perspective view of a device for repairing a weakened or fractured bone of the presently disclosed embodiments.
FIG. 2A and FIG. 2B show perspective views of a device for repairing a weakened or fractured bone of the presently disclosed embodiments. FIG. 2A shows a balloon portion of the device in a deflated state. FIG. 2B shows a balloon portion of the device in an inflated state.
FIG. 3A and FIG. 3B show close-up views of some of the main components of a device for repairing a weakened or fractured bone of the presently disclosed embodiments. FIG. 3A shows a perspective view of a distal end of the device. FIG. 3B shows a side cross-sectional view taken along line A-A of the device.
FIG. 4 shows a perspective view of a light source for use with a device for repairing a weakened or fractured bone of the presently disclosed embodiments.
FIG. 5A and FIG. 5B show cross-sectional views of a device for repairing a weakened or fractured bone of the presently disclosed embodiments. FIG. 5A shows a side cross-sectional view of the device. FIG. 5B shows a cross-sectional view of the device.
FIG. 6A, FIG. 6B, FIG. 6C, FIG. 6D and FIG. 6E show the method steps for utilizing a device of the presently disclosed embodiments for repair of a fractured bone.
FIG. 7A, FIG. 7B and FIG. 7C show illustrative embodiments of a fractured metacarpal bone in a finger of a hand.
FIG. 8A, FIG. 8B and FIG. 8C shows a device of the presently disclosed embodiments used for internal bone fixation. FIG. 8A shows the placement of the device at a metacarpal fracture in a hand of a patient. FIG. 8B shows a side view of a balloon portion of the device as the balloon portion is inflated with a reinforcing material to repair the fracture. FIG. 8C shows a side view of the balloon portion at the site of the bone fracture after the balloon portion has been released from the device.



While the above-identified drawings set forth presently disclosed embodiments, other embodiments are also contemplated, as noted in the discussion. This disclosure presents illustrative embodiments by way of representation and not limitation. Numerous other modifications and embodiments can be devised by those skilled in the art which fall within the scope and spirit of the principles of the presently disclosed embodiments.
DETAILED DESCRIPTION
Medical devices and methods for repairing a weakened or fractured bone are disclosed herein. The devices disclosed herein act as internal bone fixation devices and include a delivery catheter terminating in a releasable conformable member. During a procedure for repairing a fractured bone, the conformable member is placed within an inner cavity of a fractured bone n a deflated state. Once in place, the conformable member is expanded from a deflated state to an inflated state by the addition of at least one reinforcing material. The at least one reinforcing material is subsequently hardened within the conformable member using a light source. The hardened conformable member may then be released from the delivery catheter and sealed to enclose the at least one reinforcing material within the conformable member. The hardened conformable member remains within the inner cavity of the fractured bone and provides support and proper orientation of the fractured bone resulting in the repair, healing, and strengthening of the fractured bone.
Reinforcing materials include, but are not limited to, bone reinforcing mixtures (such as bone cement mixtures, bone void fillers, epoxies, glues and similar adhesives), orthopedic wires, stainless-steel rods, metal pins, and other similar devices. The reinforcing material may be a natural or synthetic material for strengthening, replacing, or reinforcing of bones or bone tissue. Bone reinforcing mixtures include glues, adhesives, cements, hard tissue replacement polymers, biodegradable polymers such as PLA, PGA, and PLA-PGA copolymers, natural coral, hydroxyapatite, beta-tricalcium phosphate, and various other biomaterials known in the art for strengthening, replacing or reinforcing bones. As inert materials, bone reinforcing mixtures may be incorporated into surrounding tissue or gradually replaced by original tissue. Those skilled in the art will recognize that numerous bone reinforcing mixtures known in the art are within the spirit and scope of the presently disclosed embodiments.
A device disclosed herein may be used for the repair of bones that have weakened or fractured due to any of the bone diseases including, but not limited to osteoporosis, achondroplasia, bone cancer, fibrodysplasia ossificans progressiva, fibrous dysplasia, legg calve perthes disease, myeloma, osteogenesis imperfecta, osteomyelitis, osteopenia, osteoporosis, Paget's disease, scoliosis, and other similar diseases. A device disclosed herein may be used for the repair of bones that have weakened or fractured due to an injury, for example, a fall.
Although some of the figures show the fractured bone as a metacarpal bone in the hand, those skilled in the art will recognize that the disclosed devices and methods may be used for repairing other bones including, but not limited to, the femur, tibia, fibula, humerus, ulna, radius, metatarsals, phalanx, phalanges, ribs, spine, vertebrae, clavicle and other bones and still be within the scope and spirit of the disclosed embodiments.
The main components of a device for repairing a weakened or fractured bone are shown generally in FIG. 1 in conjunction with FIG. 2A and FIG. 2B. The device 100 includes a delivery catheter 110 having an elongated shaft 101 with a proximal end 102, a distal end 104, and a longitudinal axis therebetween. In an embodiment, the delivery catheter 110 has a diameter of about 3 mm. The distal end 104 of the delivery catheter 110 terminates in a releasable conformable member 103. In an embodiment, the conformable member is a balloon portion. The balloon portion 103 may move from a deflated state (FIG. 2A) to an inflated state (FIG. 2B) when at least one reinforcing material is delivered to the balloon portion 103. In an embodiment, the balloon portion 103 has a deflated diameter of about 2.5 mm. In an embodiment, the balloon portion 103 has an inflated diameter ranging from about 4 mm to about 9 mm. The reinforcing material may be delivered to the balloon portion 103 via an inner void capable of allowing the reinforcing material to pass through. In an embodiment, a reinforcing material, such as UV-activated glue, is used to inflate and deflate the balloon portion 103. In an embodiment, the balloon portion 103 may be round, flat, cylindrical, oval, rectangular or another shape. The balloon portion 103 may be formed of a pliable, resilient, conformable, and strong material, including but not limited to urethane, polyethylene terephthalate (PET), nylon elastomer and other similar polymers. In an embodiment, the balloon portion 103 is constructed out of a PET nylon aramet or other non-consumable materials. PET is a thermoplastic polymer resin of the polyester family that is used in synthetic fibers. Depending on its processing and thermal history, PET may exist both as an amorphous and as a semi-crystalline material. Semi-crystalline PET has good strength, ductility, stiffness and hardness. Amorphous PET has better ductility, but less stiffness and hardness. PET can be semi-rigid to rigid, depending on its thickness, and is very lightweight. PET is strong and impact-resistant, naturally colorless and transparent and has good resistance to mineral oils, solvents and acids.
In an embodiment, the balloon portion 103 is designed to evenly contact an inner wall of a cavity in a bone. In an embodiment, the balloon portion 103 may have a pre-defined shape to fit inside the cavity in a particularly shaped bone. For example, as depicted in the embodiment of FIG. 1, the pre-defined shape of the balloon portion 103 may be an elongated cylinder. The balloon portion 103 has a proximal end 123, a distal end 121 and a longitudinal axis therebetween having an outer surface 122. In an embodiment, the outer surface 122 of the balloon portion 103 is substantially even and smooth and substantially mates with a wall of the cavity in the bone. In an embodiment, the outer surface 122 of the balloon portion 103 is not entirely smooth and may have some small bumps or convexity/concavity along the length. In some embodiments, there are no major protuberances jutting out from the outer surface 122 of the balloon portion 103. The balloon portion 103 may be designed to remain within the cavity of the bone and not protrude through any holes or cracks in the bone. In an embodiment, the outer surface 122 of the balloon portion 103 may be flush with the wall of the cavity and when the balloon portion 103 is inflated, the outer surface 122 may contact the wall of the cavity along at least a portion of the surface area. In an embodiment, when the balloon portion 103 is inflated, a majority or all of the balloon's 103 outer surface 122 does not contact the wall of the cavity and does not extend through any holes or cracks in the bone.
The outer surface 122 of the balloon portion 103 may be coated with materials such as drugs, bone glue, proteins, growth factors, or other coatings. For example, after a minimally invasive surgical procedure an infection may develop in a patient, requiring the patient to undergo antibiotic treatment. An antibiotic drug may be added to the outer surface 122 of the balloon portion 103 to prevent or combat a possible infection. Proteins, such as, for example, the bone morphogenic protein or other growth factors have been shown to induce the formation of cartilage and bone. A growth factor may be added to the outer surface 122 of the balloon portion 103 to help induce the formation of new bone. Due to the lack of thermal egress of the reinforcing material in the balloon portion 103, the effectiveness and stability of the coating is maintained.
In an embodiment, the outer surface 122 of the balloon portion 103 may have ribs, ridges, bumps or other shapes to help the balloon portion 103 conform to the shape of a bone cavity. Balloons may be constructed to achieve transit within luminal cavities of bones and to expand, manipulate, and remove obstructions. In this way, the balloon portion 103 may slide easier within the luminal bodies without coming in contact with surrounding tissue. The balloon portion 103 may also be designed to be placed in a bone and to grab a fractured bone without any slippage using a textured surface with a variety of shapes such as small ridges or ribs.
In an embodiment, a water soluble glue is applied to the outer surface 122 of the balloon portion 103. When the balloon portion 103 is expanded and engages a moist bone, the water soluble glue on the outer surface 122 of the balloon portion 103 becomes sticky or tacky and acts as a gripping member to increase the conformal bond of the balloon portion 103 to the bone. Once the balloon portion 103 is inflated, the outer surface 122 of the balloon portion 103 grips the bone forming a mechanical bond as well as a chemical bond. These bonds prevent the potential for a bone slippage. The water soluble glue may be cured by any light (e.g., UV not required).
In an embodiment, the balloon portion 103 has a textured surface which provides one or more ridges that allow grabbing all portions of bone fragments of a fractured bone. In an embodiment, ridges are circumferential to the balloon portion 103 and designed to add more grab to the inflated balloon portion 103 on contact with the fractured bone. The ridges are also compressive so the ridges fold up on the fractured bone when the balloon portion 103 is completely inflated. In an embodiment, sand blasted surfacing on the outer surface 122 of the balloon portion 103 improves the connection and adhesion between the outer surface 122 of the balloon portion 103 and the inner bone. The surfacing significantly increases the amount of surface area that comes in contact with the bone resulting in a stronger grip.
The balloon portion 103 of the device 100 typically does not have any valves. One benefit of having no valves is that the balloon portion 103 may be inflated or deflated as much as necessary to assist in the fracture reduction and placement. Another benefit of the balloon portion 103 having no valves is the efficacy and safety of the device 100. Since there is no communication passage of reinforcing material to the body there cannot be any leakage of material because all the material is contained within the balloon portion 103. In an embodiment, a permanent seal is created between the balloon portion 103 that is both hardened and affixed prior to the delivery catheter 110 being removed. The balloon portion 103 may have valves, as all of the embodiments are not intended to be limited in this manner.
The balloon portion 103 of the delivery catheter 110 has a diameter ranging from about 5 mm to about 9 mm. The balloon portion 103 of the delivery catheter 110 has a length ranging from about 20 mm to about 80 mm. In an embodiment, the balloon portion 103 has a diameter of about 5 mm and a length of about 30 mm. In an embodiment, the balloon portion 103 has a diameter of about 5 mm and a length of about 40 mm. In an embodiment, the balloon portion 103 has a diameter of about 6 mm and a length of about 30 mm. In an embodiment, the balloon portion 103 has a diameter of about 6 mm and a length of about 40 mm. In an embodiment, the balloon portion 103 has a diameter of about 6 mm and a length of about 50 mm. In an embodiment, the balloon portion 103 has a diameter of about 7 mm and a length of about 30 mm. In an embodiment, the balloon portion 103 has a diameter of about 7 mm and a length of about 40 mm. In an embodiment, the balloon portion 103 has a diameter of about 7 mm and a length of about 50 mm.
A stiffening member 105 surrounds the elongated shaft 101 of the delivery catheter 110 and provides rigidity over the elongated shaft 101. A pusher or stabilizer 116 is loaded proximal to the balloon portion 103. A slip sleeve 107 surrounds the stiffening member 105. In an embodiment, the slip sleeve 107 surrounds the stiffening member 105 from the proximal end 123 of the balloon portion 103 up until the pusher 116. One or more radiopaque markers or bands 130 may be placed at various locations along the balloon portion 103 and/or the slip sleeve 107. A radiopaque ink bead 133 may be placed at the distal end 121 of the balloon portion 103 for alignment of the device 100 during fluoroscopy. The one or more radiopaque bands 130, using radiopaque materials such as barium sulfate, tantalum, or other materials known to increase radiopacity, allows a medical professional to view the device 100 using fluoroscopy techniques. The one or more radiopaque bands 130 also provide visibility during inflation of the balloon portion 103 to determine the precise positioning of the balloon portion 103 and the device 100 during placement and inflation. The one or more radiopaque bands 130 permit visualization of any voids that may be created by air that gets entrapped in the balloon portion 103. The one or more radiopaque bands 130 permit visualization to preclude the balloon portion 103 from misengaging or not meeting the bone due to improper inflation to maintain a uniform balloon/bone interface.
In an embodiment, an adapter 115, such as a Tuohy-Borst adapter, engages the proximal end 102 of the delivery catheter 110. A light source that includes a light pipe 152 may be introduced into one of the side-arms of the adapter 115 and passes within an inner lumen of the delivery catheter 110 up until the distal end 104 of the delivery catheter 110. An adhesive system housing the reinforcing material may be introduced into another side-arm of the adapter 115, as shown in FIG. 2B. Alternately, a Luer fitting may engage the proximal end 102 of the delivery catheter 110 and a Luer fitting would exist on the light source such that the delivery catheter 110 and the light source would lock together.
Examples of adhesive systems include, but are not limited to, caulking gun type systems, syringe systems, bag systems that contain the bone reinforcing material where the delivery of the bone reinforcing material is controlled using a tube clamp or any other restrictor valve. In the embodiment shown in FIG. 2B, the adhesive system is a syringe 160. In an embodiment, the syringe 160 has a control mechanism that regulates the flow of the reinforcing material. The control mechanism of the syringe 160 allows the reinforcing material to flow into the delivery catheter 110 and the flow may be stopped if desired. The syringe 160 makes direct contact to control the directional flow of the reinforcing material, and the direction of flow of the reinforcing material instantaneously changes within the delivery catheter 110 in response to a change in the direction of the syringe 160.
In an embodiment, the syringe 160 is opaque and does not allow light to penetrate within the syringe 160. Having an opaque syringe 160 ensures that the reinforcing material contained in the syringe 160 is not exposed to light and will not cure in the syringe 160. The reinforcing material is of a liquid consistency, as measured in Centipoise (cP), the unit of dynamic viscosity, so the reinforcing material may be infused from the syringe 160 into the delivery catheter 110 and into the balloon portion 103. Because the reinforcing material has a liquid consistency and is viscous, the reinforcing material may be delivered using low pressure delivery and high pressure delivery is not required, but may be used.
In an embodiment, a separation area is located at the junction between the distal end 123 of the balloon portion 103 and the elongated shaft 101. The separation area may also include an illumination band. When activated, the illumination band causes light to cure the reinforcing material located in the balloon portion 103 within the illumination band. The illumination band extends around the delivery catheter 110 and has a stress concentrator. The stress concentrator may be a notch, groove, channel or similar structure that concentrates stress in the illumination band. The stress concentrator of the illumination band may be notched, scored, indented, pre-weakened or pre-stressed to direct separation of the balloon portion 103 from the elongated shaft 101 of the delivery catheter 110 under specific torsional load. The separation area ensures that there are no leaks of reinforcing material from the elongated shaft of the delivery catheter and/or the balloon portion. The separation area seals the balloon portion and removes the elongated shaft of the delivery catheter by making a break at a known or predetermined site (e.g., a separation area). The separation area may be various lengths and up to about an inch long. When torque (twisting) is applied to the delivery catheter 110, the elongated shaft 101 separates from the balloon portion 103. The twisting creates a sufficient shear to break the residual reinforcing material and create a clean separation of the balloon/shaft interface. The illumination band may be connected to the light source and may be activated by a separate switch. Having a distinct switch to activate the illumination band may help to prevent inadvertent delivery of light from the light source to cure the reinforcing material. The activation of the illumination band seals the balloon portion and seals the end of the delivery catheter, and ensures that there is a “hard seal” of the reinforcing material at the illumination band allowing no reinforcing material to leak from the balloon portion or the delivery catheter.
FIG. 3A and FIG. 3B show close-up views of some of the main components of the device 100. One or more radiopaque markers or bands 130 are placed at various locations along the slip sleeve 107 of the device 100. Those skilled in the art will recognize that radiopaque markers 130 may also be placed at various locations along the balloon portion 103. In an embodiment, the one or more radiopaque bands 130 are placed at intervals of about 10 mm along the length of the slip sleeve 107. In an embodiment, a radiopaque ink bead 133 is placed at the distal end 121 of the balloon portion 103 for easy visualization and alignment of the device 100 by fluoroscopy during a repair procedure. The radiopaque markers 130 and radiopaque ink bead 133 are formed using radiopaque material such as barium sulfate, tantalum, or other materials known to increase radiopacity. The radiopaque markers 130 provide visibility during inflation of the balloon portion 103 to determine the precise positioning of the balloon portion 103 and the delivery catheter 110 during placement and inflation. The radiopaque markers 130 permit visualization of voids created by air that may be entrapped in the balloon portion 103. The radiopaque markers 130 permit visualization to preclude the balloon portion 103 from misengaging or not meeting the surface of a bone due to improper inflation. Once the correct positioning of the balloon portion 103 and delivery catheter 110 are determined, the proximal end of the delivery catheter 110 may be attached to a delivery system that contains a reinforcing mixture.
A cross-sectional view taken along line A-A of FIG. 3A is shown in FIG. 3B. As shown in FIG. 3B, the elongated shaft 101 of the delivery catheter 110 terminates in the balloon portion 103 having the outer surface 122. Within the elongated shaft 101 of the delivery catheter 110 is a light pipe conduit 111 for accepting a light source (not shown). A void 113 for passage of a reinforcing material is formed between an inner surface 124 of the delivery catheter 110 and an outer surface 117 of the light pipe conduit 111. A delivery system comprising the reinforcing material may be attached to a side arm of a Tuohy-Borst adapter that is engaged to a proximal end of the delivery catheter 110. The reinforcing material may pass through the void 113 of the delivery catheter 110 and enter the balloon portion 103. The infusion of the reinforcing material causes the balloon portion 103 to inflate to a desired state. In an embodiment, the reinforcing material is infused through the void 113 in the delivery catheter 110 to expand the balloon portion 103 to position a bone in a healing orientation. To establish the healing orientation, the balloon portion 103 inflates until the bones move into an aligned orientation and are supported. Orientation of the bones may be done without any visualization of the process or using x-ray or a fluoroscope. In an embodiment, a C arm imaging system is used as part of a fluoroscope. The C arm imaging system may allow movement or manipulation of the fluoroscope to rotate around tissue while viewing. Other techniques may be used for monitoring or inspecting the expansion of the balloon portion 103 such as magnetic resonance imaging (MRI), ultrasound imaging, x-ray fluoroscopy, Fourier transform infrared spectroscopy, ultraviolet or visible spectroscopy. The balloon portion 103 may be composed of non ferromagnetic materials and, thus, is compatible with MRI.
As shown in FIG. 3B, the outer slip sleeve 107 surrounds the stiffening member 105. The stiffening member 105 surrounds and provides rigidity to the elongated shaft of the delivery catheter 110. The light pipe conduit 111 provides a space for a light source to pass through. The void 113 is formed between the outer surface 117 of the light pipe conduit 111 and the inner surface 124 of the delivery catheter 110. This void 113 provides a passageway for the reinforcing material. The outer surface 117 of the light pipe conduit 111 allows for a separation between the light source and the reinforcing material.
FIG. 4 in conjunction with FIG. 1 shows a light source 150 for use with the device 100 of the presently disclosed embodiments. The light source 150 is used to harden the reinforcing material that has been infused into the balloon portion 103 of the delivery catheter 110. The light source 150 includes a light pipe 152 which terminates in an optical lens 154. Energy emitted from the light pipe 152 is projected through the optical lens 154 and guided into the balloon portion 103 of the delivery catheter 110. The optical lens 154 may be convex, concave or planar. The optical lens 154 is curved to converge or diverge the transmitted energy from the light pipe 152. In an embodiment, the optical lens 154 is made out of a plastic material such as Acrylic (PMMA), Polycarbonate (PC), Polystyrene (PS), or other similar materials known to those in the art such as Cyclic Olefin Copolymer (COC), and Amorphous Polyolefin (Zeonex). In an embodiment, the optical lens 154 is made out of a glass material such as quartz.
The light source 150 is introduced into a side arm of the adapter 115 that engages the proximal end 102 of the delivery catheter 110. The light source 150 runs through the elongated shaft 101 of the delivery catheter 110 through the light pipe conduit and up into the proximal end 123 of the balloon portion 103, as shown in FIG. 1. The activation of the light source 150 cures the reinforcing material resulting in the affixing of the balloon portion 103 in an expanded shape. A cure may refer to any chemical, physical, and/or mechanical transformation that allows a composition to progress from a form (e.g., flowable form) that allows it to be delivered through the void in the delivery catheter 110, into a more permanent (e.g., cured) form for final use in vivo. For example, “curable” may refer to uncured composition, having the potential to be cured in vivo (as by catalysis or the application of a suitable energy source), as well as to a composition in the process of curing (e.g., a composition formed at the time of delivery by the concurrent mixing of a plurality of composition components).
In an embodiment, the reinforcing material is a light cure adhesive or ultraviolet (UV) adhesive. Examples of light cured materials include those commercially available from Loctite of Henkel Corporation, located in Rocky Hill, Conn. and those commercially available from DYMAX Corporation, located in Torrington, Conn. A benefit of UV curing is that it is a cure-on-demand process and that adhesives may be free of solvents and include environmentally friendly resins that cure in seconds upon exposure to long wave UV light or visible light. Different UV adhesives use photoinitiators sensitive to different ranges of UV and visible light. Being very energetic, UV light can break chemical bonds, making molecules unusually reactive or ionizing them, in general changing their mutual behavior. Visible light, for example, visible blue light, allows materials to be cured between substrates that block UV light but transmits visible light (e.g., plastics). Visible light penetrates through the adhesive to a greater depth. Since the visible light penetrates through the adhesive, curing of the adhesive increases as a greater portion of the electromagnetic spectrum is available as useful energy. Additives may be used with the UV adhesive delivery system, including, but not limited to drugs (for example, antibiotics), proteins (for example, growth factors) or other natural or synthetic additives.
The electromagnetic spectrum is the range of all possible electromagnetic radiation. The electromagnetic spectrum of an object is the frequency range of electromagnetic radiation that the object emits, reflects, or transmits. The electromagnetic spectrum extends from just below the frequencies used for modern radio (at the long-wavelength end) to gamma radiation (at the short-wavelength end), covering wavelengths from thousands of kilometers down to fractions of the size of an atom. In an embodiment, the UV adhesive is a single-component, solvent-free adhesive that will not cure until a UV light engages the adhesive, and when that occurs, the adhesive will cure in seconds to form a complete bond with a shear strength. In an embodiment, the reinforcing material exhibits a shrinkage upon cure of about 2 to about 3 percent.
UV light wavelength ranges from about 1 nm to about 380 nm, and can be subdivided into the following categories: near UV (380-200 nm wavelength; abbreviated NUV), far or vacuum UV (200-10 nm; abbreviated FUV or VUV), and extreme UV (1-31 nm; abbreviated EUV or XUV). Similarly, visible light has a wavelength spectrum of between about 380 to about 780 nm. Those skilled in the art will recognize that some UV adhesives may be activated by UV light, visible light, x-rays, gamma rays, microwaves, radio waves, long waves or any light having a wavelength less than about 1 nm, between about 1 nm and about 380 nm, between about 380 nm and about 780 nm, or greater than 780 nm, as not all embodiments are intended to be limited in that respect.
Using a UV light, the reinforcing material ensures there is no or minimal thermal egress and that the thermal egress may not be long in duration. More specifically, there is no chemical composition or mixing of materials. Using the UV light to cure the reinforcing material assists in holding broken bones in place, filling of the balloon portion, and viewing under a C arm imaging system. The reinforcing materials cure in such a way that is sufficient to hold a bone in the correct orientation. More specifically, the ability to inflate, set, adjust, orient bones, and the resulting union of the bone are available prior to hardening the reinforcing material. The introduction of the UV light starts the photoinitiator and the UV adhesive hardens. Once the UV light is introduced, the adhesive inside the balloon portion hardens and the adhesives inside are affixed in place. Until the UV light is introduced, the bone placement is not disturbed or rushed as there is no hardening of the adhesives until the light is introduced, the balloon portion may be inflated or deflated due to the viscosity of the adhesive. The adhesive may be infused or removed from the balloon portion due to the low viscosity of the adhesive. In an embodiment, the viscosity of the reinforcing material has a viscosity of about 1000 cP or less. In an embodiment, the reinforcing material has a viscosity ranging from about 650 cP to about 450 cP. Not all embodiments are intended to be limited in this respect and some embodiments may include reinforcing materials having a viscosity exactly equal to or greater than 1000 cP. In an embodiment, a contrast material may be added to the reinforcing material without significantly increasing the viscosity. Contrast materials include, but are not limited to, barium sulfate, tantalum, or other contrast materials known in the art.
Several epoxies known in the art are suitable for use as bone reinforcing materials and vary in viscosity, cure times, and hardness (durometer or shore) when fully cured. A durometer of a material indicates the hardness of the material, defined as the material's resistance to permanent indentation. Depending on the amount of resultant support that is necessary for a given bone fracture, a specific durometer UV adhesive may be chosen. Alternately, multiple UV adhesives having varying durometers may be chosen for the repair of a bone fracture and be within the scope and spirit of the presently disclosed embodiments. The durometer of a material may be altered to achieve either greater rigidity or a more malleable result. The mechanical properties of the epoxies may dictate using methods/measures that are typical for high-strength and high-impact materials including but not limited to, tensile strength and tensile modulus, tensile strength tests, ultimate modulus, Poisson's ratio, hardness measurements like Vickers and Charpy Impact which measures yield strength and toughness.
In an embodiment, the reinforcing material is cured by chemical activation or thermal activation. Chemical activation includes but is not limited to water or other liquids. In an embodiment, the reinforcing material is a drying adhesive which has a polymer dissolved in a solvent such that as the solvent evaporates, the adhesive hardens. In an embodiment, the reinforcing material is a hot or thermoplastic adhesive such that as the adhesive cools, the adhesive hardens.
The reinforcing material is not limited to the embodiments described herein and may be any material that reinforces the bone. Some materials may require or be enhanced by curing via any means, such as UV or visible light, heat, and/or addition or removal of a chemical or substance, may utilize any outside or internal processes to cure the material, or may not require curing.
In an embodiment, carbon nanotubes (CNTs) are added to the reinforcing material to increase the strength of the material. Carbon nanotubes are an allotrope of carbon that take the form of cylindrical carbon molecules and have novel strength properties. Carbon nanotubes exhibit extraordinary strength. Nanotubes are members of the fullerene structural family, which also includes buckyballs. Whereas buckyballs are spherical in shape, a nanotube is cylindrical with at least one end typically capped with a hemisphere of the buckyball structure. Nanotubes are composed entirely of sp2 bonds, similar to those of graphite. This bonding structure, which is stronger than the sp3 bonds found in diamond, provides the molecules with their unique strength. Nanotubes naturally align themselves into “ropes” held together by Van der Waals forces. Single walled nanotubes or multi-walled nanotubes may be used to strengthen the reinforcing materials.
FIG. 5A and FIG. 5B show cross-sectional views of the device 100 showing the light source passing through the light pipe conduit 111 of the delivery catheter 110. The light source includes the light pipe 152 terminating in the optical lens 154. The light source is used to harden the reinforcing material that has been infused into the balloon portion 103 of the delivery catheter 110. Energy emitted from the light pipe 152 is projected through the optical lens 154 and guided into the balloon portion 103 of the delivery catheter 110. The optical lens 154 may be convex, concave or planar. The optical lens 154 is curved to converge or diverge the transmitted energy from the light pipe 152.
In an embodiment, a fracture repair process reinforces a weakened or fractured bone without exposing the bone through a traditional surgical incision. The presently disclosed embodiments use a minimally invasive approach by making a minor incision to gain access to the bone. Minimally invasive refers to surgical means, such as microsurgical, endoscopic or arthroscopic surgical means, that can be accomplished with minimal disruption of the pertinent musculature, for instance, without the need for open access to the tissue injury site or through minimal incisions. Minimally invasive procedures are often accomplished by the use of visualization such as fiber optic or microscopic visualization, and provide a post-operative recovery time that is substantially less than the recovery time that accompanies the corresponding open surgical approach. Benefits of minimally invasive procedures include causing less trauma because there is minimal blood loss, a reduction in surgery and anesthetized time, shortened hospitalization, and an easier and more rapid recovery. In an embodiment, a bone fixator may be placed within an intramedullary cavity of a weakened or fractured bone. By restoring and preserving bone structure, some of the presently disclosed embodiments permit additional future treatment options.
FIGS. 6A-6E in conjunction with FIG. 1, illustrate the method steps for repairing a fractured bone in a patient's body. A minimally invasive incision (not shown) is made through the skin of the patient's body to expose a fractured bone 602. The incision may be made at the proximal end or the distal end of the fractured bone 602 to expose the bone surface. Once the bone 602 is exposed, it may be necessary to retract some muscles and tissues that may be in view of the bone 602. As shown in FIG. 6A, an access hole 610 is formed in the bone by drilling or other methods known in the art. In an embodiment, the access hole 610 has a diameter of about 3 mm to about 10 mm. In an embodiment, the access hole 610 has a diameter of about 3 mm.
The access hole 610 extends through a hard compact outer layer 620 of the bone into the relatively porous inner or cancellous tissue 625. For bones with marrow, the medullary material should be cleared from the medullary cavity prior to insertion of the device 100. Marrow is found mainly in the flat bones such as hip bone, breast bone, skull, ribs, vertebrae and shoulder blades, and in the cancellous material at the proximal ends of the long bones like the femur and humerus. Once the medullary cavity is reached, the medullary material including air, blood, fluids, fat, marrow, tissue and bone debris should be removed to form a void. The void is defined as a hollowed out space, wherein a first position defines the most distal edge of the void with relation to the penetration point on the bone, and a second position defines the most proximal edge of the void with relation to the penetration site on the bone. The bone may be hollowed out sufficiently to have the medullary material of the medullary cavity up to the cortical bone removed. There are many methods for removing the medullary material that are known in the art and within the spirit and scope on the presently disclosed embodiments. Methods include those described in U.S. Pat. No. 4,294,251 entitled “Method of Suction Lavage,” U.S. Pat. No. 5,554,111 entitled “Bone Cleaning and Drying system,” U.S. Pat. No. 5,707,374 entitled “Apparatus for Preparing the Medullary Cavity,” U.S. Pat. No. 6,478,751 entitled “Bone Marrow Aspiration Needle,” and U.S. Pat. No. 6,358,252 entitled “Apparatus for Extracting Bone Marrow.”
A guidewire (not shown) may be introduced into the bone 602 via the access hole 610 and placed between bone fragments 604 and 606 of the bone 602 to cross the location of a fracture 605. The guidewire may be delivered into the lumen of the bone 602 and crosses the location of the break 605 so that the guidewire spans multiple sections of bone fragments. As shown in FIG. 6B, the balloon portion 103 of the device 100 for repairing a fractured bone, which is constructed and arranged to accommodate the guidewire, is delivered over the guidewire to the site of the fracture 605 and spans the bone fragments 604 and 606 of the bone 602. Once the balloon portion 103 is in place, the guidewire may be removed. The location of the balloon portion 103 may be determined using at least one radiopaque marker 130 which is detectable from the outside or the inside of the bone 602. For example, as shown in the embodiment depicted in FIG. 6, radiopaque markers 130, which are visible from outside of the body using x-ray or other detection means, are located along both the balloon portion 103 and the slip sleeve 107 of the delivery catheter 110 to help align and position the device 100. Once the balloon portion 103 is in the correct position within the fractured bone 602, the device 100 is attached to a delivery system which contains a reinforcing material. The reinforcing material is then infused through a void in the delivery catheter 110 and enters the balloon portion 103 of the device 100. This addition of the reinforcing material within the balloon portion 103 causes the balloon portion 103 to expand, as shown in FIG. 6C. As the balloon portion 103 is expanded, the fracture 605 is reduced. In an embodiment, the reinforcing material is a UV curable glue which requires a UV light source to cure the adhesive. In an embodiment, a central space may remain in the balloon portion 103 which may be filled in order to provide extra strength and support to the fractured bone 602. An optical rod or similar device may be positioned in the central space and turned on or illuminated. An optical rod or similar device can be made of fiber, silica, quartz, sapphire or similar materials. The UV light will then harden the UV curable glue in the balloon portion 103. The end of the optical rod may be cut and remain in the balloon portion 103 to provide increased rigidity.
Once orientation of the bone fragments 604 and 606 are confirmed to be in a desired position, the UV curable glue may be hardened within the balloon portion 103, as shown in FIG. 6D, such as by illumination with a UV emitting light source. After the UV curable glue has been hardened, the light source may be removed from the device 100. The balloon portion 103 once hardened, may be released from the delivery catheter 110 by known methods in the art. In an embodiment, the delivery catheter 110 is cut to separate the balloon portion 103 from the elongated shaft 101. A device slides over the delivery catheter 110 and allows a right angle scissor to descend through the delivery catheter 110 and make a cut. The location of the cut may be determined by using a fluoroscope or an x-ray. In an embodiment, the cut location is at the junction where the elongated shaft 101 meets the balloon portion 103.
In an embodiment, the device 100 is used to treat a hand or wrist fracture. The wrist is a collection of many joints and bones that allow use of the hands. The wrist has to be mobile while providing the strength for gripping. The wrist is complicated because every small bone forms a joint with its neighbor. The wrist comprises at least eight separate small bones called the carpal bones, that connect the two bones of the forearm, called the radius and the ulna, to the bones of the hand and fingers. The wrist may be injured in numerous ways. Some injuries seem to be no more than a simple sprain of the wrist when the injury occurs, but problems can develop years later. A hand fracture may occur when one of the small bones of the hand breaks. The hand consists of about 38 bones and any one of these bones may suffer a break. The palm or midhand is made up of the metacarpal bones. The metacarpal bones have muscular attachments and bridge the wrist to the individual fingers. These bones frequently are injured with direct trauma such as a crush from an object or most commonly the sudden stop of the hand by a wall. The joints are covered with articular cartilage that cushions the joints. Those skilled in the art will recognize that the disclosed device and methods can be used for to treat fractures to other bones, such as radius, ulna, clavicle, metacarpals, phalanx, metatarsals, phalanges, tibia, fibula, humerus, spine, ribs, vertebrae, and other bones and still be within the scope and spirit of the disclosed embodiments.
The presently disclosed embodiments may be used to treat a clavicle fracture, resulting in a clavicle reduction. The clavicle or collar bone is classified as a long bone that makes up part of the shoulder girdle (pectoral girdle). Present methods to affix a broken clavicle are limited. The clavicle is located just below the surface of the skin, so the potential for external fixation including plates and screws is limited. In addition, the lung and the subclavian artery reside below the collar bone so using screws is not an attractive option. Traditional treatment of clavicle fractures is to align the broken bone by putting it in place, provide a sling for the arm and shoulder and pain relief, and to allow the bone to heal itself, monitoring progress with X-rays every week or few weeks. There is no fixation, and the bone segments rejoin as callous formation and bone growth bring the fractured bone segments together. During healing there is much motion at the fracture union because there is not solid union and the callous formation often forms a discontinuity at the fracture site. A discontinuity in the collar bone shape often results from a clavicle fracture.
The presently disclosed embodiments and methods treat a clavicle fracture in a minimally invasive manner and may be used for a clavicle reduction or collar bone reduction. A benefit of using the disclosed device to repair a collar bone is the repair minimizes post repair misalignment of collar bone. A benefit of using the disclosed device to repair a clavicle is to resolve the patient's pain during the healing process.
FIGS. 7A, 7B and 7C, in conjunction with FIGS. 8A, 8B and 8C, show a device 100 of the presently disclosed embodiments for use in repairing a fractured metacarpal bone 702 in a finger 710 in a hand 700 of a patient. As shown, the fractured metacarpal bone 702 has been split into two fragments, 704 and 706, at a break site 705. As shown in FIG. 8A, the balloon portion of the device 100 is delivered to the site of the fracture 75 and spans the bone fragments 74 and 706 of the bone 702. The location of the balloon portion may be determined using at least one radiopaque marker which is detectable from the outside or the inside of the bone 702. Once the balloon portion is in the correct position within the fractured bone 702, the device 100 is attached to a delivery system which contains a reinforcing material. The reinforcing material is then infused through a void in the delivery catheter and enters the balloon portion of the device 100. This addition of the reinforcing material within the balloon portion causes the balloon portion to expand, as shown in FIG. 8B. As the balloon portion is expanded, the fracture 705 is reduced. In an embodiment, the reinforcing material is a UV curable glue which requires a UV light source to cure the adhesive. The UV light will then harden the UV curable glue in the balloon portion.
Once orientation of the bone fragments 704 and 706 are confirmed to be in a desired position, the UV curable glue may be hardened within the balloon portion, such as by illumination with a UV emitting light source. After the UV curable glue has been hardened, the light source may be removed from the device 100. The balloon portion once hardened, may be released from the delivery catheter by known methods in the art, as shown in FIG. 8C. In an embodiment, the delivery catheter is cut to separate the balloon portion from the elongated shaft.
All patents, patent applications, and published references cited herein are hereby incorporated by reference in their entirety. It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.

## Claims

1. An internal bone fixation device comprising:
a conformable member engaging a distal end of a delivery catheter, wherein an inner lumen of the delivery catheter connects to the conformable member to guide light energy from a light source into the conformable member to minimize thermal egress of the light energy to supporting tissue from the conformable member; and
at least one reinforcing material contained within the conformable member, wherein the conformable member moves from a deflated state to an inflated state when the at least one reinforcing material is added to the conformable member, and
wherein the at least one reinforcing material is hardened by the light energy emitted from the light source.

2. The internal bone fixation device of claim 1 wherein the conformable member is constructed from a polymer material.

3. The internal bone fixation device of claim 1 for use in repairing a bone fractured into at least two bone fragments.

4. The internal bone fixation device of claim 3 wherein the conformable member resides within an inner cavity of the at least two bone fragments and provides support to the at least two bone fragments to promote healing.

5. The internal bone fixation device of claim 4 wherein the conformable member evenly contacts a wall of the inner cavity of the at least two bone fragments when in the inflated state.

6. The internal bone fixation device of claim 1 wherein the light source includes a light pipe and an optical lens.

7. The internal bone fixation device of claim 1 wherein the light source includes a light pipe that emits energy through an optical lens and guides the light energy into the conformable member.

8. The internal bone fixation device of claim 1 wherein the inner lumen of the delivery catheter directly connects to the conformable member.

9. An internal bone fixation device comprising:
at least a portion of a distal end of a delivery catheter;
a balloon portion engaging the distal end of the delivery catheter wherein an inner lumen of the delivery catheter connects to the balloon portion to guide a visible light into the balloon portion to harden a light cure adhesive within the balloon portion and to minimize thermal egress of the visible light to supporting tissue from the balloon portion; and
a hardened light cure adhesive within the balloon portion, wherein the hardened light cure adhesive has been cured by the visible light.

10. The internal bone fixation device of claim 9 wherein the balloon portion is constructed from a polymer material.

11. The internal bone fixation device of claim 9 for use in repairing a bone fractured into at least two bone fragments.

12. The internal bone fixation device of claim 9 wherein the balloon portion resides within an inner cavity of at least two bone fragments when the balloon portion is used in repairing a fractured bone.

13. The internal bone fixation device of claim 9 wherein the balloon portion evenly contacts a wall of an inner cavity of at least two bone fragments when the balloon portion is used in repairing a fractured bone.

14. The internal bone fixation device of claim 9 wherein the hardened light cure adhesive has been cured by the visible light emitted from a light source comprising a light pipe and an optical lens.

15. The device of claim 9 further comprising a plurality of ribs extending from an outer surface of the balloon portion to conform the balloon portion to a shape of a bone cavity.

16. The device of claim 9 wherein an outer surface of the balloon portion is textured.

17. The device of claim 9 wherein a textured outer surface of the balloon portion interacts with bone fragments for adhesion between the bone fragments and the textured outer surface to promote the formation of new bone onto the textured outer surface.

18. The internal bone fixation device of claim 9 wherein the inner lumen of the delivery catheter directly connects to the balloon portion.

19. A system for internal fixation of a fractured bone comprising:
a light cure adhesive curable by exposure to visible light;
a delivery catheter having an elongated shaft with a distal end and a proximal end for accepting a light pipe and the light cure adhesive, wherein the delivery catheter has an inner void for passage of the light cure adhesive and an inner lumen for passage of the light pipe; and
a balloon portion releasably engaging the distal end of the delivery catheter,
wherein the balloon portion expands from a deflated state to an inflated state when the light cure adhesive is delivered through the inner void of the delivery catheter into the balloon portion, and
wherein the inner lumen of the delivery catheter connects to the balloon portion to guide the light into the balloon portion to harden the light cure adhesive within the balloon portion and to minimize thermal egress of the light to supporting tissue from the balloon portion.

20. The system of claim 19 for use in repairing a bone fractured into at least two bone fragments.

21. The system of claim 19 wherein the balloon portion resides within an inner cavity of at least two bone fragments when the balloon portion is used in repairing a fractured bone.

22. The system of claim 19 wherein the balloon portion evenly contacts a wall of an inner cavity of at least two bone fragments when the balloon portion is used in repairing a fractured bone.

23. The system of claim 19 wherein the light cure adhesive is an ultraviolet adhesive.

24. The system of claim 19 further comprising an imaging device for monitoring expansion of the balloon portion.

25. The system of claim 24 further comprising one or more radiopaque markers positioned on the balloon portion.

26. The system of claim 25 wherein the one or more radiopaque markers on the balloon portion provide a visibility of the balloon portion while using the imaging device to determine a position of the balloon portion during placement and expansion of the balloon portion in a fractured bone.

27. The system of claim 19 further comprising a light pipe.

28. The system of claim 19 further comprising a light pipe that emits the light through an optical lens and guides the light into the balloon portion.

29. The system of claim 19 further comprising a plurality of ridges extending from an outer surface of the balloon portion to conform the balloon portion to a shape of a bone cavity.

30. The system of claim 19 wherein an outer surface of the balloon portion is textured.

31. The system of claim 19 wherein a textured outer surface of the balloon portion interacts with bone fragments for adhesion between the bone fragments and the textured outer surface to promote the formation of new bone onto the textured outer surface.

32. The system of claim 19 wherein the inner lumen of the delivery catheter directly connects to the balloon portion.

33. A method for internal fixation of a fractured bone comprising:
gaining access to an internal space within the fractured bone;
providing a device comprising a balloon portion engaging a delivery catheter, wherein the delivery catheter has an inner void for passage of a light cure adhesive to the balloon portion and an inner lumen for passage of a light pipe to the balloon portion, and wherein the balloon portion includes one or more radiopaque markers;
positioning the balloon portion of the device within the internal space of the fractured bone;
expanding the balloon portion by infusion of the light cure adhesive into the inner void of the delivery catheter and into the balloon portion;
using an imaging device to determine a position of the balloon portion and an expansion of the balloon portion within the internal space of the fractured bone by visibly monitoring the one or more radiopaque markers on the balloon portion;
inserting the light-pipe into the inner lumen of the delivery catheter and towards the balloon portion, wherein the inner lumen connects to the balloon portion to guide the light from the light pipe into the balloon portion to cure the light cure adhesive within the balloon portion and to minimize thermal egress of the light to supporting tissue from the balloon portion; and
activating the light pipe to cure the light cure adhesive.

34. The method of claim 33 wherein the inner lumen of the delivery catheter directly connects to the balloon portion.