Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
  • A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws, setting implements or the like
  • A61B17/88—Osteosynthesis instruments; Methods or means for implanting or extracting internal or external fixation devices
  • A61B17/885—Tools for expanding or compacting bones or discs or cavities therein
  • A61B17/8852—Tools for expanding or compacting bones or discs or cavities therein capable of being assembled or enlarged, or changing shape, inside the bone or disc
  • A61B17/8855—Tools for expanding or compacting bones or discs or cavities therein capable of being assembled or enlarged, or changing shape, inside the bone or disc inflatable, e.g. kyphoplasty balloons

Definitions

• Osteoporosis is a disease that gradually weakens bones and causes them to become brittle. Left untreated, osteoporosis can progress painlessly until a bone breaks. I n some cases, osteoporosis can cause compression fractures in the spine. This occurs when the bony block, or vertebral body, in the spine collapses. This causes severe pain, deformity, and loss of height. It ca n also lead to nerve compression.
• PM MA polymethylmethacrylate
• Kyphoplasty is a procedure that involves making small incisions and placing a catheter into the vertebral space where the fracture is located. A cavity is created inside the bone (e.g. drilled) and a balloon, called a bone tamp, is inserted. The balloon may be support by a guidance wire that is passed through a central lumen of the catheter. The balloon is then inflated with contrast medium until it expands to a desired height, deflated and removed. The balloon is used to expand and reposition the compressed bone, and to create a cavity for cement. The cavity created by the balloon may then be filled with PM MA, binding the fracture. Kyphoplasty substantially restores height to the spine, thus reducing deformity (also pain relief).
• the tool may include a balloon catheter that may be a two (or more) lumen catheter.
• An outer lumen may be used for inflation of the balloon and an inside lumen for guiding a double-threaded guidance wire.
• a thread in the distal part of the guidance wire may be provided with outer diameter of the distal thread being less than the inner diameter of an inner tube of the catheter.
• the construction of the thread i.e., outer diameter, inner diameter, flank lead, length
• the counter piece e.g., a distal threaded nut
• the counter piece for the distal thread of the guidance wire may be disposed inside the balloon of the catheter and connected to the inner tube. This nut can also be used as a radiopaque marker inside the balloon.
• the guidance wire may also have a proximal thread with an outer diameter greater than an outer diameter distal thread.
• the construction of the thread e.g., outer diameter, inner diameter, flank lead, length
• the counter piece e.g., a proximal threaded nut
• the proximal threaded nut may be disposed inside a luer connector (e.g., a connector for balloon inflation) of the catheter and positioned coaxial to the inner tube.
• the length of the proximal threaded nut may be longer than the distal threaded nut to account for changes of the balloon catheter during inflation.
• the double-threaded guidance wire may remain connected to the balloon during inflation to prevent the balloon and the inner tube from lengthening, substantially avoiding plastic deformation in an axial direction.
• the double-threaded guidance wire may be removed from the tool during balloon inflation. Thereafter, the double-threaded guidance wire can be reinserted into the tool to connect to the thread in the balloon to restore the pre-inflation nominal balloon axial length and stiffness before inflation.
• the double-threaded guidance wire can be reinserted into the tool to connect to the thread in the balloon to restore the pre-inflation nominal balloon axial length and stiffness before inflation.
• a reusable tool that includes a handle having a proximal thread.
• a catheter structure may be included that has an outer body and an inner body. The outer body may be connected to a fitting of the handle.
• An expandable structure may be connected to the outer body, where the expandable structure has a distal thread affixed within an interior thereof.
• a guidance wire maybe disposed within the inner body, where the guidance wire has a first threaded portion adapted to engage the proximal thread and a second threaded portion adapted to engage the distal thread.
• a reusable tool for treating a vertebral body may include a handle having an inflation port and a proximal thread.
• a dual-lumen catheter may be connected to a fitting of the handle and a balloon connected to the outer body.
• the balloon may have a distal thread affixed within an interior thereof.
• a guidance wire may be disposed within an inner lumen of the dual- lumen catheter, where the guidance wire has a first threaded portion adapted to engage the proximal thread in the handle and a second threaded portion adapted to engage the distal thread in the balloon.
• a tool for treating a vertebral body that includes a handle having an inflation port, a luer fitting and a proximal thread disposed with a body of the handle.
• a catheter body may be attached to the luer fitting of the handle.
• a balloon may be connected to the catheter body, where the balloon has a distal thread affixed within an interior thereof.
• the tool may further include a dual- threaded guidance wire having a first threaded portion adapted to engage the proximal thread and a second threaded portion adapted to engage the distal thread.
• a method for treating bone with a tool having a catheter tube assembly may include fixing a double-threaded guidance wire to a distal threaded nut of an inflatable structure, and deploying the inflatable structure inside a first location of the bone.
• the inflatable structure may be inflated to create a cavity within a treatment area of the bone, after which the inflatable structure is deflated and removed from inside the bone.
• the inflatable structure may then be reused and reinserted within the treatment area or inside a second location of the bone.
• FIG. 1 is a view of a reusable tool having an balloon structure
• FIG. 2 is a cross-sectional view of a catheter tube assembly of the reusable tool of FIG. 1;
• FIG. 3 is a view of the reusable tool of FIG. 1 showing additional details of a double-threaded guidance wire;
• FIG. 4 is a cross-sectional view of a proximal threaded nut
• FIG. 5 is a cross-sectional view of a distal threaded nut
• FIG. 6 is a cross-sectional view of the double-threaded guidance wire
• FIG. 7 illustrates an implementation to inflate the balloon structure with the double-threaded guidance wire attached thereto
• FIG. 8 is operational flow diagram of exemplary processes that are performed as part of a procedure using the implementation of FIG. 7;
• FIG. 9 illustrates an implementation to inflate the balloon structure where the double-threaded guidance wire is removed during inflation of the balloon structure and reinserted to withdraw the balloon structure;
• FIG. 10 operational flow diagram of exemplary processes that are performed as part of a procedure using the implementation of Fig. 9. DETAILED DESCRIPTION
• the tool 100 includes a catheter tube assembly 104 made from, e.g., metal or extruded plastic materials.
• the catheter tube may be generally flexible.
• the distal end of the catheter tube assembly 104 carries a balloon structure 106, which is made, e.g., from a deformable plastic or other compliant material.
• the balloon structure 106 is deployed and expanded inside bone, e.g., in a vertebral body, to compact cancellous bone and/or displace cortical bone.
• the catheter tube assembly 104 includes an outer catheter body 108 and an inner catheter body 110.
• the inner catheter body 110 extends through and beyond the outer catheter body 108 into the balloon structure 106.
• the proximal ends of the inner catheter body 110 and the outer catheter body 108 are jointly coupled to the distal end of a luer fitting 114 on a y-shaped luer connector 102, which serves as a handle for the tool 100.
• the proximal end of the inner catheter body 110 extends within the luer connector 102 beyond the coupled proximal ends of the outer catheter body 108.
• the extended proximal end of the inner catheter body 110 is coupled to the luer connector 102 at a location proximal to an inflation port 120.
• the distal end of the inner catheter body 110 extends beyond the distal end of the outer catheter body 108.
• the balloon structure 106 is coupled at its proximal end to the distal end of the outer catheter body 108.
• the balloon structure 106 is coupled at its distal end to the double-threaded guidance wire 112 that extends beyond the distal end of the inner catheter body 110.
• the double-threaded guidance wire 112 is coupled at its proximal end to a rotatable luer cap 116.
• the interior diameter of the outer catheter body 108 is larger than the exterior diameter of the inner catheter body 110.
• An interior passage 122 is thereby defined between them.
• the interior passage 122 conveys a pressurized flowable medium, e.g., sterile water, radiopaque fluid, gas, or other flowable substance into the balloon structure 106, to expand it.
• the inner catheter body 110 defines an interior lumen 124 within the interior passage 122.
• the double-threaded guidance wire 112 extends through the interior lumen 124.
• the luer cap 116 rotates about a proximal luer fitting 118 on the luer connector 102. Twisting the luer cap 116 rotates the double- threaded guidance wire 112 within the inner catheter body 110. The torque caused by twisting the luer cap 116 is transmitted to a first threaded portion 126 of the double- threaded guidance wire 112 that engages a proximal threaded nut 128 within the luer connector 102 (see, reference A).
• the proximal threaded nut 128 may be conical in shape to remain fixed against a pull force of the guidance wire 122 (described below), thus providing a form closure inside the luer connector 102.
• the proximal threaded nut 128 may also be attached to the luer connector 102 by, e.g., glue, threads, a pin, etc., such that it remains secure.
• the torque is also transmitted to a second threaded portion 132 of the double-threaded guidance wire 112 that engages a distal threaded nut 130 within the balloon structure 106 (see, reference B).
• the distal threaded nut 130 may be used as a radiopaque marker inside the balloon structure 106.
• a marker 134 may be provided that is fixed to a portion of the inner catheter body 110 that extends within the balloon structure 106.
• the marker 134 may be a radiopaque marker viewed using plain film x-ray, fluoroscopic x-ray, MRI or CT scanning.
• the threads of the nuts 128 and 130, and the guidance wire 112 can be designed both with a left-hand thread or both with a right-hand thread.
• the threads can also be designed in opposite direction (one left-hand thread and the other right-hand thread).
• the interaction of the double-threaded guidance wire 112, proximal threaded nut 128, distal threaded nut 130 and the balloon structure 106 is described below with reference to FIGS. 7-10.
• the proximal threaded nut 128 may have a length of 15-40 mm.
• the diameter of the hole of the proximal threaded nut 128 may be approximately 1.6 mm.
• the distal threaded nut 130 may be inside the balloon structure 106 and have a length of 2-3 mm.
• the diameter of the hole of the distal threaded nut 130 may be approximately 1.0 mm.
• the material from which the balloon structure 106 is made may possess various physical and mechanical properties to optimize its functional capabilities to compact cancellous bone.
• Such properties may include the ability to expand in volume, the ability to deform in a desired way when expanding and assume a desired shape inside bone, and/or the ability to withstand abrasion, tearing, and puncture when in contact with cancellous and/or cortical bone.
• the expanded shape inside bone may be selected to optimize the formation of a cavity that, when filled with a selected material (e.g., PMMA, calcium phosphate, bone chips, etc.), provides support across the region of the bone being treated.
• a selected material e.g., PMMA, calcium phosphate, bone chips, etc.
• the selection of the shape of the balloon structure 106 inside bone may take into account the cancellous bone volume which should be compacted to achieve the desired therapeutic result.
• Another consideration for the selection of the shape of the balloon structure 106 is the amount that the targeted fractured bone region has been displaced or depressed.
• the balloon structure 106 may have a predetermined length, such as 10 mm, 15 mm or 20 mm, selected based on the amount of displacement.
• the expansion of the balloon structure 106 inside a bone can elevate or push the fractured cortical wall back to or near its anatomic position occupied before fracture occurred.
• FIG. 7 there is illustrated an implementation of the tool 100 wherein the double-threaded guidance wire 112 remains fixed to the balloon structure 106 during inflation of the balloon structure 106.
• FIG. 8 illustrates an associated operational flow diagram 300 of exemplary processes that are performed as part of a procedure using the tool 100 in such an implementation.
• the double-threaded guidance wire 112 is fixed to the distal threaded nut 130 of the balloon structure 106 (see, reference 200).
• the balloon structure 106 may be folded such that the tool 100 has an axial length L.
• the balloon structure 106 is then inflated with the double- threaded guidance wire 112 fixed to the distal threaded nut 130 (see, reference 202).
• the inflation of the balloon structure 106 may, e.g., compress or create a cavity within cancellous bone and/or elevate the cortical wall of the spine.
• the tool 100 substantially remains at the axial length L in the inflated state.
• the balloon structure 106 is then deflated and the catheter tube assembly 104 may be removed at 308. Because the double-threaded guidance wire 112 remains fixed to the balloon structure 106 through the threaded engagement of the second threaded portion 132 to the distal threaded nut 130, the balloon structure 106 remains substantially at its original axial length L.
• the catheter tube assembly 104 may be reused and reinserted (at 302) and the balloon structure 106 reinflated for subsequent use.
• the tool 100 may be reused either in the same vertebral body or another vertebral body in the same patient because the balloon structure 106 remains supported by the double-threaded guidance wire 112 and, as such, has a known size.
• FIG. 10 is an associated operational flow diagram 500 of exemplary processes that are performed as part of a procedure using the tool 100 in such an implementation.
• the double-threaded guidance wire 112 is fixed to the distal threaded nut 130 of the balloon structure 106 (see, reference 400). In the delivered state, the balloon structure 106 may be folded.
• the double-threaded guidance wire 112 is removed, and the balloon structure 106 is then inflated at 506 (see, reference 402).
• the inflation of the balloon structure 106 compresses or creates a cavity within cancellous bone and/or elevates the cortical wall.
• the inflation of the expanding balloon structure 106 also expands the balloon structure 106 in the axial direction by an amount (designated by AL) to create an expansion area 136 that is unsupported.
• the balloon structure 106 is then deflated and the double- threaded guidance wire 112 is reinserted into catheter tube assembly 104 at 510 (see, reference 404).
• the double-threaded guidance wire 112 may be rotated such that the second threaded portion 132 engages the distal threaded nut 130 in the balloon structure 106.
• the double-threaded guidance wire 112 is pulled back to engage the first threaded portion 126 within the proximal threaded nut 128. As such, the length of the balloon structure 106 is restored to the original starting position, as indicated by the arrows and dashed lines.
• the catheter tube assembly 104 may be removed.
• the process ends 516.
• the catheter tube assembly 104 may be reinserted (at 502) and the process repeats for the subsequent insertion(s).
• the tool 100 may be reused either in the same vertebral body or another vertebral body in the same patient.
• the interaction of the double-threaded guidance wire 112, proximal threaded nut 128 and distal threaded nut 130 locks the guidance wire 112 into a position such that the balloon structure 106 is returned to its original length after inflation. It is noted that any locking mechanism that returns the balloon structure 106 its original length after inflation may be used in the tool 100.
• distal threaded nut 130 has been described as being within the balloon structure 106, the distal threaded nut may be either inside or outside of the balloon structure 106.
• the thread may be part of a rivet that is outside the balloon structure 106 and forms part of a tip of the balloon structure 106.

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• 2010
  • 2010-10-14 WO PCT/US2010/052717 patent/WO2012050583A1/en active Application Filing
  • 2010-10-14 JP JP2013533827A patent/JP5913331B2/ja active Active
  • 2010-10-14 EP EP10768669.3A patent/EP2627288A1/de not_active Withdrawn

Non-Patent Citations (2)

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