WO2008002992A1

WO2008002992A1 - Radiolucent external fixation element with radio-opaque alignment structures

Info

Publication number: WO2008002992A1
Application number: PCT/US2007/072267
Authority: WO
Inventors: Gene Edward Austin
Original assignee: Smith & Nephew, Inc.
Priority date: 2006-06-27
Filing date: 2007-06-27
Publication date: 2008-01-03

Abstract

A radiolucent external fixation element (11, 12, 13, 132, 142, 152) with radio-opaque alignment structures (100) is disclosed. The radio-opaque alignment structure (100) may include, among other things, wire (110), spheres (112), or paint (114). The alignment structure (100) is used to form a plane orthogonal to the axis of the bone and center the fixation element (11, 12, 13, 132, 142, 152) upon the axis of the bone.

Description

RADIOLUCENT EXTERNAL FIXATION ELEMENT WITH RADIO-OPAQUE ALIGNMENT STRUCTURES CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 60/816,696, filed June 27, 2006. The disclosure of this prior application is incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION FIELD OF THE INVENTION

[0002] The present invention relates to external fixator systems and, more particularly, external fixator systems having a radiolucent fixation element with radio-opaque alignment structures. RELATED ART

[0003] In some instances, it is necessary to stabilize skeletal fractures and osteotomies using an external fixation system. The external fixation system may be used in the repair of traumatized bone. The system structure typically includes transcutaneous pins and/or wires attached to an external structural frame and to bone. The frame may include one or more clamps, bars, connecting rods, struts, rings, 2/3 rings, half rings, foot plates, or curved rods. The frame portions are attached and spaced apart but structurally connected using a plurality of connecting rods or displacement members, such as tie rods or struts. As an example, a surgeon can use several rings and several displacement members in order to create an overall frame about the patient's arm or leg. Transversely extending pins or wires attach to these rings and then extend transversely from the rings into the bones, so that the frame and transverse pins support and/or load the bone tissue in a desired manner. [0004] A system utilizing circular or semi-circular rings with adjustable rods is generally referred to in the art as an "Ilizarov" system and can be used for the purpose of external fixation of heavily damaged or heavily traumatized bone. The "Ilizarov" method can also be used for lengthening various congenital and acquired shortenings and other defects of skeletal segments wherein the rings and adjustable tie rods form part of compression-distraction apparatus.

[0005] The "Ilizarov" method is described generally in the Oct. 8, 1989 issue of Parade Magazine in an article entitled "Stretching The Body's Power To Grow", and in U.S. Pat. No. 4,615,338, issued to Gavril A. Ilizarov et al. The '338 Pat., entitled "Automatic Compression- Distraction Apparatus," is directed to an improved compression distraction apparatus. The '338 Ilizarov patent references earlier prior art publications of the same inventor, including USSR Inventor Certificate No. 848,011, cl.A 61 B 17/18, also published in the Bulletin of Inventions No. 27,1981. A second prior art disclosure relating to a drive of a compression distraction apparatus appears in USSR Inventor Certificate No. 865,284, cl.A 61 B 17/18, published in the Bulletin of Inventions No. 35,1981. These prior Ilizarov publications all relate generally to the Ilizarov external fixation system which uses metal rings, threaded rods, threaded fasteners, and other metallic components in the fixation of fractures, limb lengthening and the correction of bone deformities.

[0006] Other external fixation systems include, as examples, the Hoffmann II External Fixation System, the Sheffield Ring Fixator, the Trans Fx External Fixation System, and the Ace- Fischer Fixator. HOFFMANN is a registered trademark of Howmedica Osteonics Corp., 325 Corporate Drive, Mahwal, New Jersey 07430. SHEFFIELD RING FIXATOR is a trademark of Orthofix Inc., 1720 Bray Central Drive, McKinney, TX 75069. TRANS FX is a trademark of Zimmer, Inc., 727 North Detroit Street, Warsaw, Indiana 46580. ACE-FISCHER is a registered trademark of Depuy Orthopaedics, Inc., 700 Orthopaedic Drive, Warsaw, Indiana 46581.

[0007] Today, the typical external frame has many elements that are radio-opaque. These elements are structural and not optimized for aligning external components with internal bone structures. For example, a surgeon might use a bolt within an Ilizarov external fixation ring to align the ring with the bone. Because the bolt is radio-opaque, the surgeon can attach the bolt to the fixator, obtain an x-ray, and then adjust the fixator using the bolt and x-ray as a guide to place the fixator relative to a bone. However, the fixator is also opaque, which it makes it difficult to see the underlying structure.

[0008] It would be very beneficial to make the external components of the external fixation system from a radiolucent material in order to provide a clear view of the underlying fracture or skeletal anatomy through an imaging device, such as an X-ray. In some instances, it would be beneficial to align a portion of the external fixation system with the skeletal anatomy. For example, an alignment reference may be used in order to avoid placing the element as to endanger soft tissue structures. Also, it would be beneficial to provide an alignment reference for frame adjustment. Finally, it may be beneficial to provide an alignment reference to place a portion of the system orthogonal to the axis of the bone being stabilized.

[0009] U.S. Patent No. 5,062,844 discloses an Ilizarov external fixation ring made of a radiolucent material. The plastic-composite fixator ring provides the advantages of being lightweight, high strength, high modulus of elasticity, and radiolucent. However, the invention of the '844 patent does not provide structure to guide placement of the ring relative to bone or soft tissue. [0010] U.S. Patent No. 6,701,174 discloses an external fixator ring having detachable visual targets to facilitate imaging and measurement of the fixator's position. See Fig. 19 and col. 20, lines 19-65. The detachable visual targets present certain difficulties or disadvantages. For example, because the visual targets are offset from the face of the ring, they may pose interference or impingement hazards during assembly of the fixation system. As another example, attachment and verification of the visual targets increase the time necessary for assembly of the fixation system. Further, the visual targets may become bent and damaged and thereby provide false indications of location. Finally, the visual targes may disengage from the ring and become lost during storage. In addition to these disadvantages, the '174 patent does not disclose a radiolucent fixation member nor does it disclose an integral alignment structure for guiding placement of the fixation member relative to bone.

[0011] There remains a need in the art for an external fixation system having a radiolucent external fixation element with an integral or embedded radio-opaque alignment marker.

SUMMARY OF THE INVENTION

[0012] There is provided an external fixation system for use in repair of a fracture of a bone. The external fixation system includes a fastener connectable to the bone and at least one radiolucent fixation element operatively connected to the fastener, the at least one radiolucent fixation element has at least one integral radio-opaque alignment structure.

[0013] According to some embodiments, the at least one radio-opaque alignment structure has a geometric structure.

[0014] According to some embodiments, the at least one radio-opaque alignment structure is a circumferential loop. [0015] According to some embodiments, the at least one radio-opaque alignment structure is formed by a single unitary structure.

[0016] According to some embodiments, the at least one radio-opaque alignment structure is a series of broken marks.

[0017] According to some embodiments, the at least one radio-opaque alignment structure comprises a plurality of beads.

[0018] According to some embodiments, the at least one radio-opaque alignment structure comprises a metal wire.

[0019] According to some embodiments, the at least one radio-opaque alignment structure is incorporated along a surface of the at least one radiolucent fixation element.

[0020] According to some embodiments, the at least one radio-opaque alignment structure is incorporated below the surface of the at least one radiolucent fixation element.

[0021] According to some embodiments, the at least one radio-opaque alignment structure comprises radio-opaque paint.

[0022] According to some embodiments, the at least one radiolucent fixation element further comprises a groove and the at least one radio-opaque alignment structure comprises radio-opaque paint painted within the groove.

[0023] According to some embodiments, the fastener is selected from the group consisting of a wire, a pin, and a screw.

[0024] According to some embodiments, the external fixation system further includes a component selected from the group consisting of a clamp, a tie rod, a strut, a fastener, a transcutaneous pin, and transcutaneous wire, and said component further comprises at least one radio-opaque alignment structure. [0025] According to some embodiments, the at least one radiolucent fixation element has spaced openings.

[0026] According to some embodiments, the at least one radiolucent fixation element is selected from the group consisting of a ring, a 2/3 ring, a half ring, a foot plate, a curved rod, and a connecting rod.

[0027] According to some embodiments, the half ring further comprises end portions.

[0028] According to some embodiments, the end portions have offset steps.

[0029] According to some embodiments, the offset steps are provided by notches.

[0030] According to some embodiments, the external fixation system further includes at least one tie rod.

[0031] According to some embodiments, the external fixation system further includes nuts placed on the at least one tie rod.

[0032] According to some embodiments, the external fixation system further includes a bolted connection.

[0033] According to some embodiments, the external fixation system further includes an adjustable strut.

[0034] According to some embodiments, the external fixation system further includes at least one radio-opaque fixation element.

[0035] According to some embodiments, the external fixation system further includes wires or pins.

[0036] According to some embodiments, the at least one radiolucent fixation element comprises a material selected from the group consisting of a polymer, a plastic, a reinforced plastic, a plastic-carbon composite, a fiber resin composite, aluminum, and a ceramic. [0037] According to some embodiments, the at least one radiolucent fixation element has a flexural stiffness of between 2.0 X 10⁴ to 5.0 X 10⁵ pounds-inch².

[0038] According to some embodiments, the at least one radiolucent fixation element comprises an epoxy/carbon-fiber composite.

[0039] According to some embodiments, the at least one radiolucent fixation element further comprises a plurality of carbon fiber braid members.

[0040] According to some embodiments, the plurality of carbon fiber braid members are oriented generally parallel to a plane of the at least one radiolucent fixation member.

[0041] Further, there is provided an external fixation system for use in repair of a fracture of a bone. The external fixation system includes a pin connected to the bone and an arcuate composite fixation member operatively connected to the pin, the composite fixation member having at least one embedded radio-opaque alignment structure.

[0042] There is also provided a method of placing an external bone fixator on a patient having an affected limb. The method includes: positioning an imaging device directly Anterior- Posterior (AP) to the affected limb; placing at least one radiolucent fixation member over the affected limb and positioned at a zone of attachment; manipulating the at least one radiolucent fixation member until the at least one radio-opaque marker aligns to form a plane orthogonal to an axis of a bone of the affected limb and centered upon the axis of the bone; and attaching the at least one fixation member to the bone.

[0043] The primary advantage of the invention is that it provides an easily seen marker for establishing a plane relative to the external fixation device. Another advantage of the invention is that it provides an external fixation system having less weight. Yet another advantage of the system is that it enhances the viewing of underlying structure during attachment of the external fixation system.

[0044] Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The accompanying drawings, which are incorporated in and form a part of the specification, illustrate the embodiments of the present invention and together with the written description serve to explain the principles, characteristics, and features of the invention. In the drawings:

[0046] FIG. 1 is a perspective view of an external fixation system;

[0047] FIG. 2 is a fragmentary perspective view of the external fixation system shown in operative position;

[0048] FIG. 3 is a fragmentary perspective view of the external fixation system illustrating use with a compression-distraction device;

[0049] FIG. 4 is a top view of a half ring element;

[0050] FIG. 5 is another top view of a second half ring element;

[0051] FIG. 6 is a side view taken in the direction indicated by lines 6—6 of FIG. 4;

[0052] FIG. 7 is a side view taken in the direction indicated by lines 7—7 of FIG. 4;

[0053] FIG. 8 is a top view of a full ring;

[0054] FIG. 9 is a side view taken in the direction indicated by lines 9—9 of FIG. 8; [0055] FIG. 10 is sectional elevational view illustrating the method of using compression moldings and prior to the mold step;

[0056] FIG. 11 is a sectional elevational view illustrating the method during compression molding;

[0057] FIG. 12 illustrates an example of an external fixation system having six degrees of freedom;

[0058] FIG. 13 illustrates an example of an external fixation system having curved fixation elements;

[0059] FIG. 14 illustrates an example of an external fixation system having straight fixation elements;

[0060] FIGS. 15 and 16 illustrate a fixation element having a radio-opaque marker;

[0061] FIGS. 17-20 illustrate various embodiments of radio-opaque markers for use in conjunction with a fixation element; and

[0062] FIG. 21 is an alternative embodiment wherein an external fixation clamp has a radio-opaque marker.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0063] The following description of the embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

[0064] FIGS. 1-3 show generally an external fixation system, designated generally by the numeral 10. The external fixation system 10 may also be termed a bone fixator apparatus. The external fixation system 10 is useful in the fixation of fractures, limb lengthening, and correction of bone deformities. The external fixation system 10 includes one or more radiolucent fixation elements 11, 12, 13. In the depicted embodiment, the external fixation system 10 includes a plurality of half rings 12, 13 that can be connected end-to-end to form full rings 11. Other types of fixation elements, such as 2/3 rings, foot plates, curved rods and connecting members, also may be used. Each half ring 12, 13 and each ring 11 includes a plurality of spaced openings 14 for the attachment of tie rods 24 therethrough. While the depicted embodiments of system 10 are shown having "half rings" and "tie rods," those of ordinary skill in the art will understand that the present invention is equally applicable to external fixation devices having "full rings" and "adjustable struts," "curved rods" and "connecting members," or "straight rods" and "connecting members." FIG. 12 illustrates an exemplary external fixation system 130 having full rings 132 and struts 134 that provides six degrees of freedom. FIG. 13 illustrates an exemplary external fixation system 140 having curved rods 142 and connecting member 144. FIG. 14 illustrates an exemplary external fixation system 150 having straight rods 152 and connecting members 154.

[0065] Referring once again to FIG. 1, each half ring 12, 13 includes end portions 15, 16 and 19, 20 respectively. The end portions 15, 16 and 19, 20 are provided with offset steps 17, 18 and 21, 22 respectively so that a pair of half rings 12, 13 can be connected together such as by bolting, for example, using bolted connections 23 (best seen in FIG. 3). In some embodiments, the offset steps may be omitted. In other embodiments, the offset steps may be provided in the form of notches to the ends of the half rings.

[0066] The plurality of openings 14 in each half ring 12, 13 and through each ring allow tie rods 24 to be inserted therethrough. Nuts 26 are placed on each tie rod 24, respectively above and below each ring 11 and/or half ring 12, 13, as shown in FIGS. 1 and 2 for the purpose of spacing the rings 11 and half rings 12, 13 apart. Thus, the rings 11, half rings 12, 13, and tie rods 24 as well as the bolted connections 23 and nuts 26 form an overall frame as shown in FIG. 1 that can be placed around a bone to be repaired after trauma or to be lengthened because of, for example, congenital deformity.

[0067] In FIG. 2, bone 27 is shown in an operative position with respect to the plurality of rings 11 and tie rods 24. Bone 27 includes upper segment 28 and lower segment 29 with fracture 30 being schematically illustrated. A plurality of transversely extending wires or pins 31 can be mounted securely to rings 11 and half rings 12, 13. This overall apparatus of rings, tie rods, bolted connections and wires/pins has typically been manufactured of metallic construction, such as steel or metallic alloy in the prior art, but non-metallic materials also may be used. FIG. 2 also shows fastener 33.

[0068] Rings 11 are assembled with two half rings 12, 13, each manufactured of a radiolucent construction of preferably plastic-carbon composite, such as epoxy/carbon-fiber composite. The plastic-carbon composite half rings include one or more carbon fiber braid members 45, 46 oriented generally parallel to the plane of the ring (See FIGS. 10 and 11). A plurality of holes 14 are spaced along the rings 11 and half rings 12, 13 and circumferential reinforcement (fibers 47— see FIGS. 10 and 11) is positioned adjacent the holes for strengthening the half ring adjacent the holes. A plurality of tie rods 24 and tie rod nuts 26 are used to affix the half rings and rings through the holes 14 in the half rings and rings for maintaining spacing between half rings 12, 13 and rings 11 during use.

[0069] FIGS. 4-7 illustrate the half rings 12, 13 in plan view (FIGS. 4 and 5) and in side view (FIGS. 6 and 7). The half rings 12, 13 can be molded in such a half ring shape, or can be molded as a full ring structure 11 as shown in FIGS. 8 and 9 so that the half rings 12, 13 could be formed by cutting the full ring 11 along the dotted line 36 of FIGS. 8 and 9 so that a single ring could be manufactured in a mold (see FIGS. 10 and 11) and then cut to form the half rings. Thus, the molded ring 11 may have a stepped portion defined by steps 34, 35 with the offset portions providing an undersurface 37 which is at the same horizontal elevation as the upper surface 38 of the ring 11. In this manner, when the rings are assembled as shown in FIGS. 1 and 2, the plane of the ring 11 will be a single plane (i.e., the two half -rings will be co-planar) because the upper surface of each half ring and the lower surface of each half ring are at the same elevation. In FIGS. 10 and 11, one particular method is illustrated for forming a ring 11 of plastic/carbon- fiber composite using compression molding.

[0070] In FIG. 10, mold 40 is shown as comprising a lower die member 41 and an upper die member 42. A cavity 43 includes a plurality of post members 44 which produce the openings 14 of the molded ring 11. Upper die 42 includes a lowermost projecting portion 42A having a plurality of sockets 44A that receives slidably the plurality of posts 44. As many posts 44 will be provided as holes 14 are desired in the final molded ring 11.

[0071] A plurality of preferably two carbon graphite braids 45, 46 are placed within the mold cavity 43, and on opposite sides of the plurality of posts 44. There is an outermost circumferentially extending carbon graphite braid member 45 that tracks the outermost curved peripheral surface 48 of the ring as shown in FIGS. 10 and 11. There is also preferably an innermost circumferentially extending carbon graphite braid member 46 which tracks inner curved surface 49. Adjacent posts 44 and openings 14, random carbon graphite fibers 47 are placed when the ring is molded. The molded article thus comprises a plastic (preferably epoxy) with inner and outer carbon graphite braids 46, 45 placed circumferentially at the innermost and outermost respective curved surfaces 49, 48 of ring 11, and with random graphite fibers 47 placed adjacent posts 44 and thus openings 14 after molding is completed. [0072] The lowermost surface 50 of lower projection 42A of upper die 42 defines an uppermost surface 38 of ring 11 as finally molded. The bottom 52 of mold cavity 43 defines the lowermost surface 51 of ring 11 upon molding. Mold cavity 43 has a vertically extending curved side wall 53 which defines the configuration of outermost circumferential curved surface 48 of ring 11. Generally vertical curved surface 54 of die member 41 defines the innermost curved circumferential surface 49 of ring 11. The rings 11 and half rings 12, 13 preferably have a flexural stiffness of between 2.0 X 10⁴ to 5.0 X 10⁵ pounds-inch ².

[0073] Referring now to FIGS. 15 and 16, each radiolucent fixation element 11, 12, 13, 132, 142, 152 may include one or more radio-opaque markers 100. The markers also may be termed alignment structures. The marker 100 may be fully integrated into the fixation element 11, 12, 13, 132, 142, 152. For example, the marker may be provided on a surface or embedded within the surface of the fixation element. The radiolucent material of the fixation element may be, as examples, a polymer, a plastic, a reinforced plastic, a plastic-carbon composite, a fiber resin composite, aluminum, or a ceramic. The radio-opaque marker material may be, as examples, polymer, steel, lead, gold, titanium, tantalum, platinum, or barium sulfate. The marker may be attached to the fixation element during the molding process. For example, the marker may be placed in the mold along with the braid members.

[0074] The marker 100 may be used to identify a plane of the fixation element. Because the fixation element is radiolucent, the radio-opaque marker 100 may be used to align the external fixator or a portion thereof with bone, such as the anatomical or mechanical axis of the bone. For example, the radio-opaque marker 100 may be a geometric structure dispensed within the fixation element 11, 12, 13, 132, 142, 152 that is more radio-opaque relative to the surrounding material. As an example, the marker 100 may be a single unitary structure, such as a solid circumferential loop, of radio-opaque material dispensed within or along an edge of the fixation element 11, 12, 13. Alternatively, the marker 100 may be a series of broken relatively radio-opaque marks that work together to form a circumferential loop. In one particular embodiment, the marker 100 takes the form of three relatively radio-opaque beads dispensed within the fixation element 11, 12, 13, 132, 142, 152. The markers 100 can be used in conjunction with an imaging device to determine a plane passing through the fixation element 11, 12, 13, 132, 142, 152 then orient that plane relative to the imaging device and a bone.

[0075] As other examples, best seen in FIGS. 17-20, the marker 100 may be made by incorporating a metal wire 110 within the fixation element 11, 12, 13, 132, 142, 152, incorporating beads (or spheres) 112 made from a relatively radio-opaque material into the fixation element material, or carefully painting strategic areas with a radio-opaque paint 114. The wire 110 or sphere 112 may be incorporated along a surface of the fixation element or incorporated below the surface. The radio-opaque paint may be painted within a groove, notch, or other depression in the fixation element.

[0076] Further, and as best seen in FIG. 21, the radio-opaque marker may be attached to other structural elements of the external fixation element, such as external fixation clamps, tie rods, connecting members, adjustable struts, fasteners, transcutaneous pins and/or wires. For example, a radio-opaque alignment star 120 may be painted onto an external fixation clamp 122.

[0077] The present invention may be used in conjunction with radio-opaque fixation elements and connection hardware. For example, some embodiments of the external fixation system may include a radiolucent fixation element and a radio-opaque fixation element.

[0078] The radio-opaque marker 100 may be used in conjunction with the following described method. In a first step, a patient is in the operating room. In a second step, a C-arm or other imaging device is positioned directly Anterior-Posterior (AP) to the affected limb. In a third step, the fixation element 11, 12, 13, 132, 142, 152 is placed over the limb and positioned at the zone of attachment. In a fourth step, via the image intensifier, the fixation element 11, 12, 13, 132, 142, 152 is manipulated until the radio-opaque markers 100 align to form a plane orthogonal to the axis of the bone and centered upon the axis of the bone. In a fifth step, pins and wires are then used to attach the fixation element 11, 12, 13, 132, 142, 152 to the bone.

[0079] In view of the foregoing, it will be seen that the several advantages of the invention are achieved and attained.

[0080] The embodiments were chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated.

[0081] As various modifications could be made to the exemplary embodiments, as described above with reference to the corresponding illustrations, without departing from the scope of the invention, it is intended that all matter contained in the foregoing description and shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by any of the above- described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents.

Claims

CLAIMSWhat is claimed is:

1. An external fixation system for use in repair of a fracture of a bone, the external fixation system comprising: a. a fastener connectable to the bone; and b. at least one radiolucent fixation element operatively connected to the fastener, the at least one radiolucent fixation element having at least one integral radio-opaque alignment structure.

2. The external fixation system according to claim 1, wherein the at least one radio-opaque alignment structure has a geometric structure.

3. The external fixation system according to claims 1 or 2, wherein the at least one radio- opaque alignment structure is a circumferential loop.

4. The external fixation system according to any of claims 1-3, wherein the at least one radio-opaque alignment structure is comprised of a single unitary structure.

5. The external fixation system according to any of claims 1-3, wherein the at least one radio-opaque alignment structure is a series of broken marks.

6. The external fixation system according to any of claims 1-3 and 5, wherein the at least one radio-opaque alignment structure comprises a plurality of beads.

7. The external fixation system according to any of claims 1-4, wherein the at least one radio-opaque alignment structure comprises a metal wire.

8. The external fixation system according to any of claims 1-7, wherein the at least one radio-opaque alignment structure is incorporated along a surface of the at least one radiolucent fixation element.

9. The external fixation system according to any of claims 1-7, wherein the at least one radio-opaque alignment structure is incorporated below the surface of the at least one radiolucent fixation element.

10. The external fixation system according to any of claims 1-5 and 8, wherein the at least one radio-opaque alignment structure comprises radio-opaque paint.

11. The external fixation system according to claim 1 , wherein the at least one radiolucent fixation element further comprises a groove and the at least one radio-opaque alignment structure comprises radio-opaque paint painted within the groove.

12. The external fixation system according to any of claims 1-11, wherein the fastener is selected from the group consisting of a wire, a pin, and a screw.

13. The external fixation system according to any of claims 1-12, further comprising a component selected from the group consisting of a clamp, a tie rod, a strut, a fastener, a transcutaneous pin, and transcutaneous wire, and said component further comprises at least one radio-opaque alignment structure.

14. The external fixation system according to any of claims 1-13, wherein the at least one radiolucent fixation element has spaced openings.

15. The external fixation system according to any of claims 1-14, wherein the at least one radiolucent fixation element is selected from the group consisting of a ring, a 2/3 ring, a half ring, a foot plate, a curved rod, and a connecting rod.

16. The external fixation system according to claim 15, wherein the half ring further comprises end portions.

17. The external fixation system according to claim 16, wherein the end portions have offset steps.

18. The external fixation system according to claim 17, wherein the offset steps are provided by notches.

19. The external fixation system according to any of claims 1-15, further comprising at least one tie rod.

20. The external fixation system according to claim 19, further comprising nuts placed on the at least one tie rod.

21. The external fixation system according to any of claims 1-15, further comprising a bolted connection.

22. The external fixation system according to any of claims 1-15, further comprising an adjustable strut.

23. The external fixation system according to any of claims 1-15, further comprising at least one radio-opaque fixation element.

24. The external fixation system according to any of claims 1-15, further comprising wires or pins.

25. The external fixation system according to any of claims 1-15, wherein the at least one radiolucent fixation element comprises a material selected from the group consisting of a polymer, a plastic, a reinforced plastic, a plastic-carbon composite, a fiber resin composite, aluminum, and a ceramic.

26. The external fixation system according to claim 25, wherein the at least one radiolucent fixation element has a flexural stiffness of between 2.0 X 10⁴ to 5.0 X 10⁵ pounds-inch².

27. The external fixation system according to claim 25, wherein the at least one radiolucent fixation element comprises an epoxy/carbon-fiber composite.

28. The external fixation system according to claim 25, wherein the at least one radiolucent fixation element further comprises a plurality of carbon fiber braid members.

29. The external fixation system according to claim 28, wherein the plurality of carbon fiber braid members are oriented generally parallel to a plane of the at least one radiolucent fixation element.

30. A method of placing an external bone fixator on a patient having an affected limb, the method comprising: a. positioning an imaging device directly Anterior-Posterior (AP) to the affected limb; b. placing at least one radiolucent fixation member over the affected limb and positioned at a zone of attachment; c. manipulating the at least one radiolucent fixation member until the at least one radio-opaque marker aligns to form a plane orthogonal to an axis of a bone of the affected limb and centered upon the axis of the bone; and d. attaching the at least one fixation member to the bone.