WO2007073488A2

WO2007073488A2 - Expendable support device and method of use

Info

Publication number: WO2007073488A2
Application number: PCT/US2006/048678
Authority: WO
Inventors: E. Skott Greenhalgh; John Paul Romano
Original assignee: Stout Medical Group, L.P
Priority date: 2005-12-19
Filing date: 2006-12-19
Publication date: 2007-06-28
Also published as: WO2007073488A3

Abstract

This relates to devices for providing support for biological tissue, for example to repair spinal compression fractures, and methods of using the same. In particular, deices and methods are described for an expanding stent structure that can brace and stabilize a damaged vertebral body (or any other anatomical structure) from within the body. The expanding stent structure is one that expands in response to an applied axially compressive force.

Description

TITLE OF THE INVENTION EXPANDABLE SUPPORT DEVICE AND METHOD OF USE

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims the benefit of U.S. Provisional Application No. 60/752, 180, filed 19 December 2005, which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] This invention relates to devices for providing support for biological tissue, for example to repair spinal compression fractures, and methods of using the same. In particular, deices and methods are described for an expanding stent structure that can brace and stabilize a damaged vertebral body (or any other anatomical structure) from within the body. The expanding stent structure is one that expands in response to an applied axially compressive force. The devices described herein may be especially useful for treating vertebral compression fractures. [0003] This invention relates to devices for providing support for biological tissue, for example to repair spinal compression fractures, and methods of using the same. [0004] Vertebroplasty is a therapy used to strengthen a broken vertebra that has been weakened by disease, such as osteoporosis or cancer. Vertebroplasty is often used to treat compression fractures, such as those caused by osteoporosis, cancer, or stress. Vertebroplasty is also often performed as an image-guided, minimally invasive procedure. [0005] Vertebroplasty is often performed on patients too elderly or frail to tolerate open spinal surgery, or with bones too weak for surgical spinal repair. Patients with vertebral damage due to a malignant tumor may sometimes benefit from vertebroplasty. The procedure can also be used in younger patients whose osteoporosis is caused by long-term steroid treatment or a metabolic disorder. [0006] Vertebroplasty can increase the patient's functional abilities, allow a return to the previous level of activity, and prevent further vertebral collapse. Vertebroplasty attempts to also alleviate the pain caused by a compression fracture. [0007] Vertebroplasty is often accomplished by injecting an orthopedic cement mixture through a needle into the fractured bone. The cement mixture can leak from the bone, potentially entering a dangerous location such as the spinal canal. The cement mixture, which is naturally viscous, is difficult to inject through small diameter needles, and thus many practitioners choose to "thin out" the cement mixture to improve cement injection, which ultimately exacerbates the leakage problems. The flow of the cement liquid .also naturally follows the path of least resistance once it enters the bone - naturally along the cracks formed during the compression fracture. This further exacerbates the leakage. [0008] The mixture also fills or substantially fills the cavity of the compression fracture and is limited to certain chemical composition, thereby limiting the amount of otherwise beneficial compounds that can be added to the fracture zone to improve healing. Further, a balloon must first be inserted in the compression fracture and the vertebra must be expanded before the cement is injected into the newly formed space. [0009] A vertebroplasty device and method that eliminates or reduces the risks and complexity of the existing art is desired. A vertebroplasty device and method that is not based on injecting a liquid directly into the compression fracture zone is desired.

BRIEF DESCRIPTION OF THE DRAWINGS [0010] Figure Ia illustrates a variation of a method for assembling a variation of the expandable support device with expandable support sub-devices. [0011] Figure Ib illustrates a variation of cross-section A-A of Figure IA. [0012] Figure 2a illustrates a variation of the expandable support device in a radially contracted configuration. [0013] Figure 2b illustrates a variation of cross-section B-B of Figure 2A. [0014] Figure 3 is a side view of a variation of a method for radially expanding a variation of the expandable support device into a radially expanded configuration. [0015] Figure 4 is a perspective view of Figure 3. [0016] Figure 5 is a perspective view of a variation of an expandable support sub- device. [0017] Figure 6 is an end view of a variation of an expandable support sub-device of Figure 5. [0018] Figure 7 illustrates a variation of the expandable support device in a radially contracted configuration. [0019] Figure 8 illustrates a variation of the expandable support device of Figure 7 in a radially expanded configuration. [0020] Figures 9 and 10 illustrate a variation of method for making a variation of the expandable support sub-device. [0021] Figure 11 illustrates a variation of method for radially expanding the expandable support sub-device of Figure 10. [0022] Figures 12a, 12b and 12c are, respectively, side, perspective and end views of a variation of the expandable support sub-device in a radially contracted configuration. [0023] Figures 13a, 13b and 13c are, respectively, side, perspective and end views of the expandable support sub-device of Figures 12a- 12c in a radially expanded configuration. [0024] Figure 14 illustrates a variation of the expandable support sub-device. [0025] Figure 15 is a side view of a variation of the expandable support sub-device in a radially contracted and unlocked configuration. [0026] Figures 16a and 16b are, respectively, side and perspective views of the expandable support sub-device of Figure 15 in a radially expanded and locked configuration. [0027] Figures 17 and 18 are, respectively, perspective and top views of a variation of the expandable support device. [0028] Figures 19 and 20 are, respectively, perspective and top views of a variation of a method for assembling and deploying the expandable support devices of Figures 17 and 18. [0029] Figure 21 illustrates a variation of a method for assembling and deploying a variation of the expandable support devices. [0030] Figure 22 illustrates variations of methods for deploying the expandable support devices in a patient..

DETAILED DESCRIPTION [0031] More than one expandable support sub-device 100, such as a stent or other ■ expandable frame, can be coupled together (e.g., coaxially) to form a radially layered - expandable support device 300, for example a composite support structure. The layers can be formed by the expandable support sub-devices 100. The expandable support device 300 can stabilize damaged tissue (e.g., forming a fusion device for vertebral bodies, vertebral discs, etc.) The expandable support device 300 can have a layered structure. The expandable support device 300 can have variable characteristics (e.g., strength, stress-strain characteristics, drug elution quantities and release times, etc.) depending upon the number of expandable support sub-devices 100 used to form the expandable support device 300. [0032] Figs. Ia, Ib, 2a and 2b illustrate that the expandable support device 300 can be formed by placing, as shown by arrow in Figure 1 a, a first expandable support sub- device 100a into a second support sub-device 100b. As shown, the expandable support sub-devices can have a plurality of struts 102a, 102b and a plurality of spaces 104a, 104b between the struts 102a, 102b. The expandable support sub-devices can have first ends 106a, 106b, and second ends 108a, 108b. The ends 106, 108 can be attached or integral with the struts 102. The ends 106, 108 can be collars. The ends 106, 108 can be radially non-expandable. The structure between the ends (e.g., the struts 102a, 102b) can be radially expandable. The expandable support sub-devices 100 can have one or more expandable ends. The ends 106, 108 can be removed from the struts 102. [0033] The expandable support device 300 can have any number of struts 2. The expandable support sub-devices 100 can be coupled (i.e., each layer connected to the layer above or below it) and/or decoupled (i.e., each layer not connected to an adjacent layer) to each other. The expandable support sub-devices 100 can be placed angularly out of phase with each other. For example, the struts 102 from adjacent expandable support sub-devices 100 can block the spaces 104 between struts 102 of the expandable support sub-devices 100 above or below the given expandable support sub-device 100. [0034] As shown in Figure Ia, the expandable support sub-devices 100a, 100b can each have a longitudinal axis 101a, 101b. As shown in Figure Ia, the first expandable support sub-device 100a can have a first inner diameter 103a and a first outer diameter 105a. The second expandable support sub-device 100b can have a second inner diameter 103b and a second outer diameter 105b. The first outer diameter 105a can be less than the second inner diameter 105b. [0035] The first expandable support sub-device 100a can be translated into a longitudinal channel 107b of the second expandable support sub-device 100b, as shown by arrow hi Figure Ia. The first longitudinal axis 101a can be aligned with the second longitudinal axis 101b. [0036] Figs. 3 and 4 illustrate that the expandable support device 300 can be longitudinally compressed, shown by arrows 150, and longitudinally contracted. The expandable support device 300 can radially expand, as shown by arrows 152. The expandable support device 300 can be expanded when the plurality of expandable support sub-devices 100a, 100b are longitudinally contained within each other and coaxial. The second expandable support sub-device 100b can be radially expanded and then the first expandable support sub-device 100a can be inserted into the second longitudinal channel 107b and radially expanded. The struts 102b of the second expandable support sub-device 100b can block the spaces 104a between the struts 102a of the first expandable support sub-device 100a. [0037] The expandable support device 300 can have adjustable properties that depend upon the number of expandable support sub-devices 100. For example, each individual expandable support sub-device 100 can add radiopacity to the expandable support device 300. The number of expandable support sub-devices 100 can provide added radial force for stabilizing tissue. The porosity of the expandable support device 300 can be selected or adjusted based on the number of individual expandable support sub-devices 100 that are used to assemble the expandable support device 300. Each layer (i.e., each individual expandable support sub-device 100) or selective layers can engage into one or more adjacent layers above or below to assist in locking the expandable support device 300 in a radially expanded configuration. One or more expandable support sub-devices 100 can be selected from different materials such as any materials disclosed herein, for example, metals, plastics, biodegrading polymers, ceramics, polymers of varying characteristics, etc. [0038] One or more expandable support sub-devices 100 can be made of a varying wall thickness. The varying wall thickness can cause the expandable support sub- device 100 to assume certain shapes. The struts 102 can also be connected at varying angles, for example, to vary the shape of the expandable support sub-devices 100. For example, one or more expandable support sub-devices 100 can be shaped to open into non round shapes: tapers, flat sided spheres (e.g., ovaloids),^"and combinations thereof. [0039] Figures 5 and 6 illustrate that the expandable support sub-devices 100 can have only a few, thick struts 102. Figures 7 and 8 illustrates that the struts 102 can be a large number of small individual filaments that are connected at the ends 106 and 108. The expandable support sub-device 100 can be combined with expandable support sub-devices 100 of similar design or expandable support sub-devices 100 of a design as described herein. Fig. 8 illustrates that the expandable support devices 300 can have spaces 104 that access or the longitudinal channel 107, or can be without the spaces 104 (e.g., if enough filament struts 102 are used and/or the filament struts 102 are woven or braided). [0040] Figure 9 shows another variation of a expandable support sub-device 100. The expandable support sub-device 100 can be constructed from a single sheet of material cut to form the struts 102, spaces 104, ends 106, 108, or combinations thereof. [0041] Figure 10 illustrates the expandable support sub-device 100 of Fig. 9 in a rolled, radially contract configuration (e.g., for rolled for insertion into the body). Figure 11 illustrates the expandable support sub-device 100 in an expanded configuration. The expandable support sub-device 100 can be combined with any number of additional expandable support sub-device 100 to form the expandable support device 300 as described herein. [0042] Figure 9 illustrates that an expandable support device 300 can be fabricated from a single sheet. The expandable support sub-device 100 can be rolled upon itself ^' to create a multi layer expandable support device 300. The struts 102 can overlap to form successive layers. The expandable support sub-device 100 can be rolled to place the struts 102 out of phase so that the single piece functions as an expandable support device 300. [0043] Figures 12a-12c and Figures 13a-13c illustrate that the expandable support sub-device 100 can have a plurality of struts 102 forming a number of spaces 104 between the struts. A strut thickness 142 can be the dimension of the strut 102 in a radial direction with respect to the longitudinal axis 101. A strut width 140 can be the dimension of the strut 102 on the surface of the expandable support sub-device 100. .The strut width 102 to strut thickness ratio (aspect ratio) can be about 2 to 1. For example, if the strut width is 1 mm, the strut thickness can be equal to or less than about 0.5mm. A device expansibility probability factor (DEPF) for basic geometry can be resolved. The DEPF is the strut thickness to strut width ratio for each strut, in the example above, this ratio can be equal to or greater than 2. One can determine the number of struts as a function of tube diameter: number struts = ((PI)*(OD))/(tube wall thickness (OD-ID)*2). [0044] For example, a tube with an OD of 10 and an ID of 9 nun can have a 1 mm wall thickness, its circumference will be 31.41. ((PI)*10)/((l)*(2)) = 62 or 62 struts. This assumes no distance between the struts. A typical laser kerf width is ,025mm. Therefore we will need 63 cuts (number of struts plus 1 cut). [0045] One can determine the space 104 between struts 102 once the device is expanded as follows: space 104 between struts 102: ((expanded device diameter)*(PI0)/number of struts) - (strut width). The space between each strut after expansion doubles each time diameter doubles. If the diameter of the tube increase 5 times, then we might make a 5 layer expandable support device 300 to fill in the spaces 104. The characteristics described above may change based on the intended target area of the device. [0046] About 2 to about 6 expandable support sub-devices 100 can be used to form a single expandable support device 300, for example, creating about 2 to about 6 layers. The layered structure (i.e., expandable support device 300) can block the spaces 104 between struts 102. The layered structure can add greater radial force to the expandable support device 300. Each layer can be connected or not connected (e.g., decoupled) to the layer above or below the given expandable support sub-device 100. The expandable support sub-devices 100 can be placed out of phase with each other, for example, so each new layer blocks the space 104 left between struts 102 of the layer above or below it. [0047] The expandable support sub-devices 100 can have varying wall thickness. The expandable support sub-devices 100 can have a changing cross-sectional profile along their lengths. The expandable support sub-devices 100 can have a square cross- section or other non-circular cross section. One or more expandable support sub- devices 100 can have a center locking mechanism/structure. The locking mechanism can help increase the expandable support device 300 overall radial structural rigidity (e.g., maximum structural force load). [0048] The expandable support sub-devices 100 can be resilient (e.g., self expanding) and/or deformable (e.g., balloon or other deployment tool-expandable). The expandable support sub-devices 100 can be restrained, for example for resilient expandable support devices 30O₅ and the restraint released to effect expansion. The expandable support sub-devices 100 can be made from a shape memory alloy to achieve a certain shape upon reaching body temperature. The expandable support sub-devices 100 can be fabricated from tubes via laser cutting, EDM, chemical etching, or combinations thereof. [0049] Figure 6 illustrates that the expandable support sub-device 100 can have struts 102c that are of a different dimension (e.g., longer) that the surrounding struts 102. These struts 104c can produce geometric changes in the expandable support sub- devices 100. For example, the struts 104c can protrude radially outward from the remaining struts 102. Also for example, the struts 104c can produce differently shaped spaces 104. [0050] Figure 15 illustrates that the expandable support sub-device 100 can have side plates 130 attached by the struts 102. The expandable support sub-device 100 can also have a center locking structure 110. The locking structure 110 can have opposed teeth on separate arms. The locking structure 110 can have two saw-tooth members that lockably engage. [0051] Figures 16a and 16 illustrate the expandable support sub-device 100 in a radially expanded, longitudinally contracted, and locked configuration. As the expandable support sub-device 100 radially expands and longitudinally contracts, the locking structure 110 can lock, significantly strengthening the expandable support sub-device 100. For example, the strengthening can reduce or completely prevent longitudinal expansion, and thereby radial compression, of the expandable support sub-device 100. [0052] Figures 17 and 18 illustrate the expandable support device 300 that can be radially expanded and/or assembled by sliding multiple components together. [0053] Figures 19 and 20 illustrate that the expandable support device 300 can comprises a first support sub-device 200a and a second support sub-device 200b. The expandable support device 300 can have a fusion device 200b that slips into the space between vertebral bodies in a number of pieces (e.g., 2-3 or more pieces). The first support sub-device 200a can be slid against the second support sub-device 200b, for example in slidably attachable tracks or grooves (not shown). As shown in Figure 20, the first support sub-device 200a and second support sub-device 200b can slide upon one another to assemble and expand. [0054] For example, the configuration of Figures 19 and 20 can permit implantation of me expandable support device 300 with a minimum width. The support sub- devices 200 can lock and create a larger support or fusion device. Additional width can be added to the expandable support device 300 by "stacking" additional support sub-devices 200 side by side. The number of support devices 200 to use to create the expandable support device 300 can be decided during the procedure, for example, as shown in Figure 21 , the expandable support device width can be controlled by number of support sub-devices 200 used. [0055] The first support sub-device 200a can be placed in a target site (e.g., in the vertebra or other treatment site). The second support sub-device 200b can be slid into place against the first support sub-device 200a, as shown by arrow in Figures 19 and 20 along a first sliding axis 201. The second support sub-device 200b can be deployed to the second support sub-device site 200b'. [0056] Figure 21 illustrates that the second support sub-device 200b can be slid, as shown by arrow 250a, into place along the first sliding axis 201a. The second support sub-device 200b can be deployed to the second support sub-device site 200b'. The third support sub-device 200c can be slid, as shown by arrow 250b, into place along the second sliding axis 201b. The third support sub-device 200c can be deployed to the third support sub-device site 200c' . [0057] As shown in Figure 21, the second support sub-device 200b can be configured to fit in the middle of the expandable support device 300. Multiple second support sub-devices 200b can be deployed until the desired width of the expandable support device 300 is achieved (deployment can be observed directly or under visualization techniques such as fluoroscopy, x-ray, MRI, acoustic visualization (e.g., ultrasound), or combinations thereof). [0058] The third support sub-device 200c can be configured to fit on an end of the expandable support device. When the desired width of the expandable support device 300 is achieved, or achieved sans the width of the third support sub-device 200c, the third support sub-device 200c can be deployed. [0059] This procedure can be performed with a small, minimally invasive, access port. This procedure can minimize nerve (e.g., spinal cord) manipulation when performing Tranforaminal Lumbar Interbody Fusion (TLIF) or Posterior Lumbar Interbody Fusion (PLIF). [0060] Figure 22 illustrates that a first deployment tool 38a can enter through the subject's back. The first deployment tool 38a can enter through a first incision 66a in skin 68 on the posterior side of the subject near the vertebral column 46. The first deployment tool 38a can be translated, as shown by arrow 70, to position a first expandable support device 300a into a first damage site 52a. The first access port 64a can be on the posterior side of the vertebra 48. [0061] With or without having an incision, the expandable support device 300 can be driven through the tissue (i.e., including the skin, if desired). For example, the distal engager 30 can cut tissue, for example with a sharpened edge. [0062] A second deployment tool 38b can enter through a second incision 66b (as shown) in the skin 68 on the posterior or the first incision 66a. The second deployment tool 38b can be translated through muscle (not shown), around nerves 72, , and anterior of the vertebral column 46. The second deployment tool 38b can be steerable. The second deployment tool 38b can be steered, as shown by arrow 74, to align the distal tip of the second expandable support device 300b with a second access port 64b on a second damage site 52b. The second access port 64b can face anteriorly. The second deployment tool 38b can translate, as shown by arrow 76, to position the second expandable support device 300 in the second damage site 52b. [0063] The vertebra 48 can have multiple damage sites 52 and expandable support devices 300 deployed therein. The expandable support devices 300 can be deployed from the anterior, posterior, both lateral, superior, inferior, any angle, or combinations of the directions thereof. [0064] The expandable support devices can be deployed in a vertebra, and/or between vertebra, and/or as a replacement for a vertebra. [0065] The deployment tool can be a pair of wedges, an expandable jack, other expansion tools, any other deployment tool described in the applications incorporated by reference, or combinations thereof. [0066] The expandable support devices 300 in Figure 22 are shown in assembled configurations, but the deployment shown could be of expandable support sub- devices 100 that can be assembled in vivo. [0067] Additional variations of the expandable support device 300 and methods for use of the expandable support device, as well as devices for deploying the expandable support device 300 can include those disclosed in the following applications which are all incorporated herein in their entireties: PCT Application No. PCT/US2005/034115, filed 21 September 2005; U.S. Provisional Patent Application No. 60/675,543 , filed 27 April 2005; PCT Application No. PCT/US2005/034742, filed 26 September 2005; PCT Application No. PCT/US2005/034728, filed 26 September 2005; PCT Application No. PCT/US2005/037126, filed 12 October 2005; U.S. Provisional Patent Application No. 60/723,309, filed 4 October 2005; U.S. Provisional Patent Application No. 60/675,512, filed 27 April 2005; U.S. Provisional Patent Application No. 60/699,577, filed 14 July 2005; and U.S. Provisional Patent Application No. 60/699,576, filed 14 July 2005. [0068] Any or all elements of the expandable support device 300 and/or other devices or apparatuses described herein can be made from, for example, a single or multiple stainless steel alloys, nickel titanium alloys (e.g., Nitinol), cobalt-chrome alloys (e.g., ELGILOY® from Elgin Specialty Metals, Elgin, IL; CONICHROME® from Carpenter Metals Corp., Wyomissing, PA), nickel-cobalt alloys (e.g., MP35N® from Magellan Industrial Trading Company, Inc., Westport, CT), molybdenum alloys (e.g., molybdenum TZM alloy, for example as disclosed in International Pub. No. WO 03/082363 A2, published 9 October 2003 , which is herein incorporated by reference in its entirety), tungsten-rhenium alloys, for example, as disclosed in International Pub. No. WO 03/082363, polymers such as polyethylene teraphathalate (PET), polyester (e.g., DACRON® from E. I. Du Pont de Nemours and Company, Wilmington, DE), poly ester amide (PEA), polypropylene, aromatic polyesters, such as liquid crystal polymers (e.g., Vectran, from Kuraray Co., Ltd., Tokyo, Japan), ultra high molecular weight polyethylene (i.e., extended chain, high-modulus or high- performance polyethylene) fiber and/or yarn (e.g., SPECTRA® Fiber and SPECTRA® Guard, from Honeywell International, Inc., Morris Township, NJ, or DYNEEMA® from Royal DSM N. V., Heerlen, the Netherlands), polytetrafluoroethylene (PTFE), expanded PTFE (ePTFE), polyether ketone (PEK), polyether ether ketone (PEEK), poly ether ketone ketone (PEKK) (also poly aryl ether ketone ketone), nylon, polyether-block co-polyamide polymers (e.g., PEBAX® from ATOFINA, Paris, France), aliphatic polyether polyurethanes (e.g., TECOFLEX® from Thermedics Polymer Products, Wilmington, MA), polyvinyl chloride (PVC), polyurethane, thermoplastic, fluorinated ethylene propylene (FEP), absorbable or resorbable polymers such as polyglycolic acid (PGA), poly-L-glycolic acid (PLGA), polylactic acid (PLA), poly-L-lactic acid (PLLA), polycaprolactone (PCL), polyethyl acrylate (PEA), polydioxanone (PDS), and pseudo-polyamino tyrosine-based acids, extruded collagen, silicone, zinc, echogenic, radioactive, radiopaque materials, a biomaterial (e.g., cadaver tissue, collagen, allograft, autograft, xenograft, bone cement, morselized bone, osteogenic powder, beads of bone) any of the other materials listed herein or combinations thereof. Examples of radiopaque materials are barium sulfate, zinc oxide, titanium, stainless steel, nickel-titanium alloys, tantalum and gold. [0069] Any or all elements of the expandable support device 300 and/or other devices or apparatuses described herein, can be, have, and/or be completely or partially coated with agents and/or a matrix a matrix for cell ingrowth or used with a fabric, for example a covering (not shown) that acts as a matrix for cell ingrowth. The matrix and/or fabric can be, for example, polyester (e.g., DACRON® from E. I. Du Pont de Nemours and Company, Wilmington, DE), poly ester amide (PEA), polypropylene, PTFE, ePTFE, nylon, extruded collagen, silicone, any other material disclosed herein, or combinations thereof. [0070] The expandable support device 300 and/or elements of the expandable support device 300 and/or other devices or apparatuses described herein and/or the fabric can be filled, coated, layered and/or otherwise made with and/or from cements, fillers, glues, and/or an agent delivery matrix known to one having ordinary skill in the art and/or a therapeutic and/or diagnostic agent. Any of these cements and/or fillers and/or glues can be osteogenic and osteoinductive growth factors. [0071] Examples of such cements and/or fillers includes bone chips, demineralized bone matrix (DBM), calcium sulfate, coralline hydroxyapatite, biocoral, tricalcium phosphate, calcium phosphate, polymethyl methacrylate (PMMA), biodegradable ceramics, bioactive glasses^ hyaluronic acid, lactoferrin, bone morphogenic proteins (BMPs) such as recombinant human bone morphogenetic proteins (rhBMPs), other materials described herein, or combinations thereof. [0072] The agents within these matrices can include any agent disclosed herein or combinations thereof, including radioactive materials; radiopaque materials; cytogenic agents; cytotoxic agents; cytostatic agents; thrombogenic agents, for example polyurethane, cellulose acetate polymer mixed with bismuth trioxide, and ethylene vinyl alcohol; lubricious, hydrophilic materials; phosphor cholene; anti- inflammatory agents, for example non-steroidal anti-inflammatories (NSAIDs) such " as cyclooxygenase-1 (COX-I) inhibitors (e.g., acetylsalicylic acid, for example ASPIRIN® from Bayer AG, Leverkusen, Germany; ibuprofen, for example ADVIL® from Wyeth, Collegeville, PA; indomethacin; mefenamic acid), COX-2 inhibitors (e.g., VIOXX® from Merck & Co., Inc., Whitehouse Station, NJ; CELEBREX® from Pharmacia Corp., Peapack, NJ; COX-I inhibitors); immunosuppressive agents, for example Sirolimus (RAPAMUNE®,-from Wyeth, Collegeville, PA), or matrix metalloproteinase (MMP) inhibitors (e.g., tetracycline and tetracycline derivatives) that act early within the pathways of an inflammatory response. Examples of other agents are provided in Walton et al,^' Inhibition of Prostaglandin E₂ Synthesis in Abdominal Aortic Aneurysms, Circulation, July 6, 1999, 48-54; Tambiah et al, Provocation of Experimental Aortic Inflammation Mediators and Chlamydia Pneumoniae, Brit. J. Surgery 88 (7), 935-940; Franklin et al, Uptake of Tetracycline by Aortic Aneurysm Wall and Its Effect on Inflammation and Proteolysis, Brit. J. Surgery 86 (6), 771-775; Xu et al, SpI Increases Expression of Cyclooxygenase-2 in Hypoxic Vascular Endothelium, J. Biological Chemistry 275 (32) 24583-24589; and Pyo et al, Targeted Gene Disruption of Matrix Metalloproteinase-9 (Gelatinase B) Suppresses Development of Experimental Abdominal Aortic Aneurysms, J. Clinical Investigation 105 (11), 1641-1649 which are all incorporated by reference in their entireties. [0073] It is apparent to one skilled in the art that various changes and modifications can be made to this disclosure, and equivalents employed, without departing from the spirit and scope of the invention. Elements shown with any variation are exemplary for the specific variation and can be in used on or in combination with other variations within this disclosure.

Claims

CLAIMS We claim: 1. An expandable support device for orthopedic deployment comprising: a first expandable frame forming a first hollow; and a second expandable frame; wherein the second expandable frame is inside the first hollow.

2. The device of Claim 1, wherein the second expandable frame is substantially entirely within the first hollow.

3. The device of Claim 1 , wherein the first expandable frame

4. The device of Claim 1, wherein the second frame forms a second hollow

5. The device of Claim 1, further comprising a third expandable frame, wherein the third expandable frame is inside the second hollow

6. The device of Claim 1 , wherein the second hollow has a filler

7. The device of Claim 6, wherein the filler comprises a bone protein

8. The device of Claim 1, wherein the first expandable frame has a first inner diameter, and wherein the second expandable frame has a second outer diameter, and wherein the first inner diameter is larger than the second outer diameter.

9. The device of Claim 1, wherein the first expandable frame has a first longitudinal axis, and wherein the second expandable frame has a second longitudinal axis, and wherein the first longitudinal axis is substantially concurrent with the second longitudinal axis.

10. The device of claim 11 , wherein the first expandable frame comprises struts, a first end and a second end, and wherein the struts are located between the first end and the second end, and wherein the first end of the first expandable frame is substantially radially rigid.

11. The device of Claim 10, wherein the second end of the first expandable frame is substantially radially rigid.

12. The device of Claim 10, wherein the second expandable frame comprises struts, a first end and a second end, and wherein the struts are located between the first end and the second end, and wherein the first end of the second expandable frame is substantially radially rigid.

13. The device of Claim 10, wherein the second end of the second expandable frame is substantially radially rigid.

14. The method of claim 16, where the first and second ends of the first expandable device are substantially radially rigid.

15. A method of supporting orthopedic tissue within a patient, the method comprising: inserting a first expandable frame within the tissue, the first expandable frame having a first longitudinal axis, and the first expandable frame comprising a first strut and a second strut; expanding the first expandable frame; inserting a second expandable frame within the first expandable frame, the second expandable frame having a second longitudinal axis, the second expandable frame comprising two struts; expanding the second expandable frame within the first expandable frame. - -

16. The method of Claim 15, wherein the inserting the second expandable frame comprises translating along the second longitudinal axis.

17. The method of Claim 15, wherein during at least part of the inserting, the second longitudinal axis is substantially concurrent with the first longitudinal axis.

18. The method of Claim 15, the method of claim 1 , wherein the first expandable frame expands in diameter upon application of a longitudinal compressive force.

19. The method of Claim 15, the method of claim 1, wherein the first expandable frame forms openings between adjacent struts.

20. The method of Claim 19, wherein in a radially expanded configuration, the second expandable frame blocks at least some openings of the first expandable frame.

21. The method of claim 15, where the first expandable frame comprises a first end and a second end, and wherein the structure between the first and second ends , where the structure is expandable.

22. The method of claim 21, where the first and second ends of the first expandable device are substantially radially rigid.