WO2020095745A1 - 椎体間ケージ - Google Patents

椎体間ケージ Download PDF

Info

Publication number
WO2020095745A1
WO2020095745A1 PCT/JP2019/042133 JP2019042133W WO2020095745A1 WO 2020095745 A1 WO2020095745 A1 WO 2020095745A1 JP 2019042133 W JP2019042133 W JP 2019042133W WO 2020095745 A1 WO2020095745 A1 WO 2020095745A1
Authority
WO
WIPO (PCT)
Prior art keywords
pair
interbody cage
rod
slider
axial direction
Prior art date
Application number
PCT/JP2019/042133
Other languages
English (en)
French (fr)
Inventor
河野　護
Original Assignee
Ｋｉｓｃｏ株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ｋｉｓｃｏ株式会社 filed Critical Ｋｉｓｃｏ株式会社
Priority to US17/292,202 priority Critical patent/US12004962B2/en
Priority to EP19883048.1A priority patent/EP3878412A4/en
Publication of WO2020095745A1 publication Critical patent/WO2020095745A1/ja

Links

Images

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/02—Prostheses implantable into the body
    • A61F2/30—Joints
    • A61F2/44—Joints for the spine, e.g. vertebrae, spinal discs
    • A61F2/4455—Joints for the spine, e.g. vertebrae, spinal discs for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/02—Prostheses implantable into the body
    • A61F2/30—Joints
    • A61F2/44—Joints for the spine, e.g. vertebrae, spinal discs
    • A61F2/442—Intervertebral or spinal discs, e.g. resilient
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/02—Prostheses implantable into the body
    • A61F2/30—Joints
    • A61F2/44—Joints for the spine, e.g. vertebrae, spinal discs
    • A61F2/4455—Joints for the spine, e.g. vertebrae, spinal discs for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages
    • A61F2/447—Joints for the spine, e.g. vertebrae, spinal discs for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages substantially parallelepipedal, e.g. having a rectangular or trapezoidal cross-section
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/02—Prostheses implantable into the body
    • A61F2/30—Joints
    • A61F2002/30001—Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof
    • A61F2002/30108—Shapes
    • A61F2002/30199—Three-dimensional shapes
    • A61F2002/30261—Three-dimensional shapes parallelepipedal
    • A61F2002/30266—Three-dimensional shapes parallelepipedal wedge-shaped parallelepipeds
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/02—Prostheses implantable into the body
    • A61F2/30—Joints
    • A61F2002/30001—Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof
    • A61F2002/30316—The prosthesis having different structural features at different locations within the same prosthesis; Connections between prosthetic parts; Special structural features of bone or joint prostheses not otherwise provided for
    • A61F2002/30329—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
    • A61F2002/30331—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements made by longitudinally pushing a protrusion into a complementarily-shaped recess, e.g. held by friction fit
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/02—Prostheses implantable into the body
    • A61F2/30—Joints
    • A61F2002/30001—Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof
    • A61F2002/30316—The prosthesis having different structural features at different locations within the same prosthesis; Connections between prosthetic parts; Special structural features of bone or joint prostheses not otherwise provided for
    • A61F2002/30329—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
    • A61F2002/30331—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements made by longitudinally pushing a protrusion into a complementarily-shaped recess, e.g. held by friction fit
    • A61F2002/30359—Pyramidally- or frustopyramidally-shaped protrusion and recess
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/02—Prostheses implantable into the body
    • A61F2/30—Joints
    • A61F2002/30001—Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof
    • A61F2002/30316—The prosthesis having different structural features at different locations within the same prosthesis; Connections between prosthetic parts; Special structural features of bone or joint prostheses not otherwise provided for
    • A61F2002/30329—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
    • A61F2002/30383—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements made by laterally inserting a protrusion, e.g. a rib into a complementarily-shaped groove
    • A61F2002/3039—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements made by laterally inserting a protrusion, e.g. a rib into a complementarily-shaped groove with possibility of relative movement of the rib within the groove
    • A61F2002/30398—Sliding
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/02—Prostheses implantable into the body
    • A61F2/30—Joints
    • A61F2002/30001—Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof
    • A61F2002/30316—The prosthesis having different structural features at different locations within the same prosthesis; Connections between prosthetic parts; Special structural features of bone or joint prostheses not otherwise provided for
    • A61F2002/30329—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
    • A61F2002/30405—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements made by screwing complementary threads machined on the parts themselves
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/02—Prostheses implantable into the body
    • A61F2/30—Joints
    • A61F2002/30001—Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof
    • A61F2002/30316—The prosthesis having different structural features at different locations within the same prosthesis; Connections between prosthetic parts; Special structural features of bone or joint prostheses not otherwise provided for
    • A61F2002/30329—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
    • A61F2002/30471—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements connected by a hinged linkage mechanism, e.g. of the single-bar or multi-bar linkage type
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/02—Prostheses implantable into the body
    • A61F2/30—Joints
    • A61F2002/30001—Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof
    • A61F2002/30316—The prosthesis having different structural features at different locations within the same prosthesis; Connections between prosthetic parts; Special structural features of bone or joint prostheses not otherwise provided for
    • A61F2002/30329—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
    • A61F2002/30476—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements locked by an additional locking mechanism
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/02—Prostheses implantable into the body
    • A61F2/30—Joints
    • A61F2002/30001—Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof
    • A61F2002/30316—The prosthesis having different structural features at different locations within the same prosthesis; Connections between prosthetic parts; Special structural features of bone or joint prostheses not otherwise provided for
    • A61F2002/30329—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
    • A61F2002/30476—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements locked by an additional locking mechanism
    • A61F2002/30507—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements locked by an additional locking mechanism using a threaded locking member, e.g. a locking screw or a set screw
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/02—Prostheses implantable into the body
    • A61F2/30—Joints
    • A61F2002/30001—Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof
    • A61F2002/30316—The prosthesis having different structural features at different locations within the same prosthesis; Connections between prosthetic parts; Special structural features of bone or joint prostheses not otherwise provided for
    • A61F2002/30535—Special structural features of bone or joint prostheses not otherwise provided for
    • A61F2002/30537—Special structural features of bone or joint prostheses not otherwise provided for adjustable
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/02—Prostheses implantable into the body
    • A61F2/30—Joints
    • A61F2002/30001—Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof
    • A61F2002/30316—The prosthesis having different structural features at different locations within the same prosthesis; Connections between prosthetic parts; Special structural features of bone or joint prostheses not otherwise provided for
    • A61F2002/30535—Special structural features of bone or joint prostheses not otherwise provided for
    • A61F2002/30537—Special structural features of bone or joint prostheses not otherwise provided for adjustable
    • A61F2002/30538—Special structural features of bone or joint prostheses not otherwise provided for adjustable for adjusting angular orientation
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/02—Prostheses implantable into the body
    • A61F2/30—Joints
    • A61F2002/30001—Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof
    • A61F2002/30316—The prosthesis having different structural features at different locations within the same prosthesis; Connections between prosthetic parts; Special structural features of bone or joint prostheses not otherwise provided for
    • A61F2002/30535—Special structural features of bone or joint prostheses not otherwise provided for
    • A61F2002/30537—Special structural features of bone or joint prostheses not otherwise provided for adjustable
    • A61F2002/30556—Special structural features of bone or joint prostheses not otherwise provided for adjustable for adjusting thickness
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/02—Prostheses implantable into the body
    • A61F2/30—Joints
    • A61F2002/30001—Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof
    • A61F2002/30316—The prosthesis having different structural features at different locations within the same prosthesis; Connections between prosthetic parts; Special structural features of bone or joint prostheses not otherwise provided for
    • A61F2002/30535—Special structural features of bone or joint prostheses not otherwise provided for
    • A61F2002/30593—Special structural features of bone or joint prostheses not otherwise provided for hollow
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/02—Prostheses implantable into the body
    • A61F2/30—Joints
    • A61F2002/30001—Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof
    • A61F2002/30316—The prosthesis having different structural features at different locations within the same prosthesis; Connections between prosthetic parts; Special structural features of bone or joint prostheses not otherwise provided for
    • A61F2002/30535—Special structural features of bone or joint prostheses not otherwise provided for
    • A61F2002/30594—Special structural features of bone or joint prostheses not otherwise provided for slotted, e.g. radial or meridian slot ending in a polar aperture, non-polar slots, horizontal or arcuate slots
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/02—Prostheses implantable into the body
    • A61F2/30—Joints
    • A61F2/30767—Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
    • A61F2/30771—Special external or bone-contacting surface, e.g. coating for improving bone ingrowth applied in original prostheses, e.g. holes or grooves
    • A61F2002/30772—Apertures or holes, e.g. of circular cross section
    • A61F2002/30777—Oblong apertures
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/02—Prostheses implantable into the body
    • A61F2/30—Joints
    • A61F2/30767—Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
    • A61F2/30771—Special external or bone-contacting surface, e.g. coating for improving bone ingrowth applied in original prostheses, e.g. holes or grooves
    • A61F2002/30772—Apertures or holes, e.g. of circular cross section
    • A61F2002/30784—Plurality of holes

Definitions

  • the present invention relates to an interbody cage that is mounted as an implant between the vertebral bodies of two vertebrae adjacent to the upper and lower sides of the spine during surgery for spinal disorders such as lumbar spinal canal stenosis, degenerative spondylolisthesis, and herniated disc.
  • an interbody cage is mounted between two vertebral bodies adjacent to each other above and below the spine to reinforce the vertebral bodies while maintaining a stable shape close to normal.
  • Spinal fusion is performed.
  • Patent Document 1 discloses an open interbody cage.
  • the interbody cage of Patent Document 1 includes a main body having a pair of branched portions that are vertically separated by a slit, a screw provided on the main body so as to extend along the slit, and a cylindrical shape into which the screw is screwed. It is composed of a roller.
  • the roller moves in the axial direction of the screw due to the rotation of the screw, but at this time, the roller slides on the oblique bearing surface on the distal end side of each branch to move each branch. Pushing up or pushing down separates the bifurcations from each other and opens the interbody cage.
  • Each branch has an opening that is continuous with the slit on the proximal side, and the vertical spacing of the openings is large, so that each branch includes a narrowed portion with a narrowed thickness on the proximal side. There is. Due to the narrowed portion, each branch portion can be flexibly deformed when being deformed so as to be separated from each other as the roller moves.
  • the vertebral body can be adjusted by adjusting the degree of dilatation of the interbody cage according to the height and angle between the vertebral bodies where the interbody cage is mounted.
  • the intercatheter allows for inter-body reinforcement suitable for the patient.
  • the present invention has been made to solve the above problems, and an object of the present invention is to provide an interbody cage having structural stability.
  • the interbody cage of the present invention is to be mounted between adjacent vertebral bodies of the spine, and has a pair of branch portions provided on the tip side and provided with a pair of vertical branch portions, and a pair of the above-mentioned main bodies.
  • a rod provided on the main body so as to extend between the branch portions, and a slider for vertically separating the pair of branch portions, the slider being supported by the rod so as to be movable in the axial direction
  • the pair of branching portions are provided with inclined surfaces facing each other and gradually increasing the distance toward the tips on the tip side, and the slider is on the inclined surfaces of the pair of branching portions when moving in the axial direction of the rod.
  • the pair of branch portions are provided with narrowed portions having a narrowed thickness at the proximal end side, respectively, and a hole whose upper and lower edges form a convex curve in a side view is provided between the upper and lower narrowed portions.
  • a plurality of rods are formed in the axial direction of the rod. It is characterized by having a mouth portion.
  • the slider includes two abutting surfaces that correspond to the inclined surfaces of the pair of branch portions in a one-to-one correspondence, and the two abutting surfaces are As the slider moves in the axial direction of the rod, it slides on the corresponding inclined surface.
  • the two abutting surfaces make surface contact with the corresponding inclined surfaces when the pair of bifurcations receive pressure from the upper and lower vertebral bodies.
  • the most proximal hole of the plurality of holes has a shape of a part of an ellipse elongated in the axial direction of the rod.
  • the plurality of the holes have a radius of curvature of the convex curve that decreases toward the distal end side.
  • the opening has a taper shape that vertically expands toward the distal end side in a side view.
  • the main body and the slider are made of a biocompatible material.
  • the slider moves in the axial direction of the rod to slide on the inclined surface of each branch portion of the main body, and pushes up or down the inclined surface respectively to make each branch portion a distal end.
  • the interbody cage is expanded.
  • the intervertebral bodies can be adjusted to normal height and angle, so the spine correction suitable for the patient (recovery of lordosis angle, Acquisition) is possible.
  • the inter-vertebral body cage is surely reinforced between the vertebral bodies, and it is possible to prevent the vertebral bodies from being collapsed due to the pressure received from the upper and lower vertebral bodies. is there.
  • the interbody cage of the present invention when each branch portion is bent and deformed by the movement of the slider, the stress generated in the narrowed portion of each branch portion becomes high, and this stress is caused by the base of the opening. Although it is easy to concentrate in the portion near the end position, by forming the opening by connecting multiple holes, the stress concentrated in the hole at the base end position of the opening can be dispersed to the adjacent holes. The stress concentration on the hole at the base end position of can be relieved. Therefore, it is possible to suppress the maximum stress generated in the narrowed portion of each branch portion, and it is possible to favorably prevent the narrowed portion from being damaged. Therefore, the interbody cage having structural stability can be provided.
  • FIG. 1 is a perspective view of an interbody cage.
  • FIG. 2 is a perspective view of the interbody cage.
  • FIG. 3 is a plan view of the interbody cage.
  • FIG. 4 is a side view of the interbody cage.
  • FIG. 5 is a front view of the interbody cage.
  • FIG. 6 is a rear view of the interbody cage.
  • FIG. 7 is a longitudinal sectional view of the interbody cage.
  • FIG. 8 is a perspective view of the main body.
  • FIG. 9 is a perspective view of the main body.
  • FIG. 10 is a plan view of the main body.
  • FIG. 11 is a side view of the main body.
  • FIG. 12 is a rear view of the main body.
  • FIG. 13 is a sectional view of the main body.
  • FIG. 14 is a perspective view of the rod.
  • FIG. 15 is a side view of the rod.
  • FIG. 16 is a perspective view of the slider.
  • FIG. 17 is a perspective view of the slider.
  • FIG. 18 is a plan view of the slider.
  • FIG. 19 is a side view of the slider.
  • FIG. 20 is a perspective view of the interbody cage in an expanded state.
  • FIG. 21 is a sectional view of the interbody cage in an expanded state.
  • FIG. 22 shows a state in which the interbody cage is mounted between vertebrae.
  • the interbody cage of the present invention is a lumbar spinal canal stenosis, degenerative spondylolisthesis of the spine, in the operation of spinal diseases such as disc herniation, for the purpose of rectifying the spine and promoting bone fusion by grafted bone, etc.
  • This is for mounting between the vertebral bodies of two vertically adjacent vertebrae to reinforce the vertebral bodies so that the vertebral bodies are stably maintained at heights and angles close to normal.
  • the interbody cage 1 includes a main body 2 having a pair of bifurcated portions 20 and 21 on the distal end side, a rod 3 built in the main body 2, and a slider movably supported on the distal end side of the rod 3 in the axial direction. 4 and.
  • the slider 4 side is defined as the front side (tip side) and the opposite side (base 22 side of the main body 2) is the rear side in the longitudinal direction of the interbody cage 1 having a long shape. (Proximal side).
  • the main body 2 is made of a biocompatible material.
  • a metal material such as titanium, titanium alloy, stainless steel, or polyether ether ketone (PEEK), polypropylene (PP), polyethylene terephthalate (A plastic material such as PET) can be preferably exemplified, and among them, PEEK, which has good visibility of bone union during image diagnosis after surgery, can be most preferably exemplified. Since PEEK has elasticity (hardness) almost equal to that of bone, when pressure is applied to the intervertebral body cage 1 between the upper and lower vertebral bodies with the interbody cage 1 mounted between the upper and lower vertebral bodies. It can prevent depression of the vertebral body and pressure on the nerve.
  • the main body 2 includes a pair of branch portions 20 and 21 extending in the lengthwise direction, and a base portion 22 connecting the both branch portions 20 and 21. It has a substantially U-shaped structure.
  • the base portion 22 has a recessed portion 23 having a bottom and a circular cross-sectional view, which extends in the lengthwise direction when the rear end face is subjected to a spot facing process.
  • the head 30 of the rod 3 is rotatably fitted in the recess 23.
  • an insertion hole 24 through which the rod-shaped portion 31 of the rod 3 is inserted is formed in the bottom of the recess 23.
  • the outer shape of the insertion hole 24 is smaller than the head portion 30 of the rod 3, and the head portion 30 of the rod 3 abuts the bottom of the recess 23 without passing through the insertion hole 24.
  • the pair of branch parts 20 and 21 are provided with a space above and below.
  • the pair of branch portions 20 and 21 are integrally connected at their base ends (rear ends) to the base 22 and can be deformed so that their front ends (front ends) open vertically.
  • the pair of branch portions 20 and 21 include a tapered portion 25 on the tip side, the thickness of which gradually decreases toward the tip.
  • the tapered portion 25 has an inner surface (a lower surface at the branching portion 20 and an upper surface at the branching portion 21) forms an inclined surface 26A that is linearly inclined in a cross-sectional view.
  • the inclined surfaces 26A of the respective branch portions 20 and 21 face each other and are spaced apart gradually toward the tip, and have a V shape.
  • the inclination angle of the inclined surface 26A of each branch portion 20, 21 is preferably 15 ° or more and 35 ° or less, and 20 ° or more and 30 ° or less, with respect to the flat surface 26B adjacent to the rear side of the inclined surface 26A. Is more preferable.
  • the pair of branch portions 20 and 21 are provided with a pair of guide walls 28 on both side edges (left and right side edges) of the tapered portion 25 in the width direction. Both guide walls 28 are arranged adjacent to the left and right side surfaces of the spacing portion 42 so as to sandwich the spacing portion 42 of the slider 4. Both guide walls 28 have a function of guiding the slider 4 so as to move straight in the axial direction of the rod 3 without rotating in the circumferential direction of the rod 3 when the slider 4 moves along the axial direction of the rod 3.
  • the outer surfaces of the pair of branch portions 20 and 21 are substantially parallel to each other, and the centers in the lengthwise direction are curved so as to be convex outward. It has an arch shape.
  • a plurality of sawtooth-shaped projections 29 are provided on the outer surfaces of the pair of branch portions 20 and 21 at intervals in the lengthwise direction. The plurality of protrusions 29 perform a function of fixing the interbody cage 1 between the vertebral bodies by being bitten into the upper and lower vertebral bodies and the intervertebral disc when the interbody cage 1 is mounted between the vertebral bodies.
  • An orifice 53 penetrating in the vertical direction is formed in the center of the pair of branch portions 20 and 21 in the width direction.
  • the orifice 53 is for accommodating a fragment of the transplanted bone for favorably performing bone repair between the vertebral bodies, and has an elongated hole shape extending in the length direction of each of the branch portions 20 and 21.
  • the rod 3 is made of a biocompatible material.
  • a metal material such as titanium, titanium alloy, stainless steel, or polyether ether ketone (PEEK), polypropylene (PP), polyethylene terephthalate (A preferable example is a plastic material such as PET), and among them, a titanium alloy is the most preferable example.
  • the rod 3 is provided in the main body 2 so as to extend in the lengthwise direction between the branched portions 20 and 21, and the shaft of the rod 3 is provided.
  • the direction is the same as the length direction of each of the branch portions 20 and 21.
  • a bolt is used for the rod 3 in the present embodiment, and for example, a head portion 30 having a hexagonal hole, a rod-shaped portion 31 protruding from the head portion 30, and a head portion 30 on the base end side of the rod-shaped portion 31 and a predetermined distance.
  • a collar portion 32 provided with a hole.
  • the head 30 is supported in the recess 23 of the base 22 of the main body 2.
  • the rod-shaped portion 31 projects between the pair of branch portions 20 and 21 of the main body 2 and extends between the branch portions 20 and 21 to the vicinity of the tip.
  • a male screw portion 33 that is screwed into a female screw portion 41 of the slider 4 to be described later is formed on the outer peripheral surface of the rod-shaped portion 31 on the tip side.
  • the collar portion 32 sandwiches the bottom of the recessed portion 23 with the head portion 30 and thus functions as a stopper that restricts the axial movement of the rod 3.
  • the slider 4 is made of a biocompatible material.
  • a metal material such as titanium, titanium alloy, and stainless steel, or polyether ether ketone (PEEK), polypropylene (PP), polyethylene terephthalate (A plastic material such as PET) can be preferably exemplified, and among them, PEEK which has good visibility of bone union during image diagnosis after surgery and has elasticity close to that of bone is most preferable. be able to.
  • the slider 4 has a through hole 40 formed therein from the rear end surface to the front end surface, and the inner wall surface forming the through hole 40 has A female screw portion 41 is formed.
  • the slider 4 is supported by the rod 3 by screwing the male screw portion 33 of the rod 3 into the female screw portion 41, and the male screw portion 33 is screwed in by the rotation of the rod 3 so that the slider 4 moves.
  • the rod 3 is movable in the axial direction toward the base end side (head 30 side).
  • the slider 4 includes a separating portion 42 that vertically separates the pair of branching portions 20 and 21 of the main body 2 by moving toward the base end side in the axial direction of the rod 3.
  • the separation part 42 has a substantially isosceles trapezoidal shape in a cross-sectional view, and two upper and lower parts, which respectively correspond to the inclined surfaces 26A of the pair of branch parts 20 and 21 in a one-to-one correspondence, at positions corresponding to the oblique sides of the substantially isosceles trapezoid.
  • the contact surface 43 is provided.
  • Each contact surface 43 is linearly inclined in a sectional view, gradually widens toward the front end surface of the slider 4, and has a V shape.
  • the inclination angle of each contact surface 43 is larger and steeper than the inclination angle of the corresponding inclined surface 26A.
  • the inclination angle of each contact surface 43 is 20 ° or more with respect to the upper and lower flat surfaces 45 of the shaft portion 44 that is adjacent to the contact surface 43 and that is continuously provided on the rear end side of the spacing portion 42.
  • the angle is preferably 40 ° or less, more preferably 25 ° or more and 35 ° or less.
  • each contact surface 43 contacts the corresponding inclined surfaces 26A of the pair of branch portions 20 and 21 of the main body 2. There is. Then, as shown in FIGS. 20 and 21, when the slider 4 moves toward the rear end side in the axial direction of the rod 3, each contact surface 43 slides on the corresponding inclined surface 26A. At this time, each contact surface 43 pushes up or pushes down the corresponding inclined surface 26A to deform the pair of branch portions 20 and 21 so that the tip ends open vertically, and thus the pair of branch portions 20 and 21 are separated. It is separated from the parallel state up and down, and as a result, the interbody cage 1 is dilated.
  • the interbody cage 1 can be opened up and down, depending on the height and angle between the vertebral bodies to which the interbody cage 1 is mounted. By adjusting the degree of openness of the interbody cage 1, the interbody cage 1 can provide interbody reinforcement suitable for the patient.
  • the slider 4 includes a pair of positioning protrusions 46 that restrict the movement of the intervertebral body cage 1 toward the distal end side in the axial direction with respect to the rod 3 in the initial state before the interbody cage 1 is expanded.
  • the pair of positioning protrusions 46 projects from the upper and lower flat surfaces 45 of the shaft portion 44, respectively.
  • each positioning protrusion 46 abuts on the front end in the longitudinal direction of the opening edge forming the orifice 53 of the pair of branch portions 20 and 21 of the main body 2.
  • the slider 4 is positioned with respect to the main body 2, and movement of the slider 4 toward the tip end side in the axial direction with respect to the rod 3 is restricted.
  • the vertical distance between the pair of branch portions 20 and 21 is increased vertically from the base end position close to the base portion 22 of the main body 2 over a predetermined length.
  • an opening 5 having a large interval vertically is provided. Due to the opening 5, the pair of branch portions 20 and 21 of the main body 2 include a narrowed portion 27 with a reduced thickness on the base 22 side (base end side). Due to the narrowed portion 27, the pair of branch portions 20 and 21 can be flexibly deformed when the tip end side of the slider 4 is deformed so as to open up and down as the slider 4 moves. The branch portions 20 and 21 can be separated from each other.
  • the opening 5 is formed by connecting a plurality of (three in the present embodiment) holes 50, 51, 52 in the length direction (axial direction of the rod 3).
  • a plurality of holes 50, 51, 52 the upper edge and the lower edge form a convex curve in a side view, and the convex curves of the upper edge and the convex curves of the lower edge of adjacent holes 50, 51, 52 are adjacent to each other. Due to the smooth connection, the opening 5 has a gourd shape in a side view between the upper and lower narrowed portions 27.
  • the plurality of holes 50, 51, 52 have different radii of curvature of the convex curves at the upper edge and the lower edge, and the radii of curvature become smaller toward the tip side of the respective branch portions 20, 21. That is, of the plurality of holes 50, 51, 52, the radius of curvature of the first hole 50 on the most proximal side (the rearmost side) near the proximal position is the largest, and the second hole adjacent to the first hole 50 has the largest radius of curvature. The radius of curvature of the hole 51 is next largest, and the radius of curvature of the third hole 52 on the most distal side (frontmost) farthest from the base end position is smallest.
  • the upper edge and the lower edge of the first hole 50 are smoothly connected to each other on the side opposite to the side where the second hole 51 is adjacent by a convex curve having a smaller radius of curvature than the convex curve of the upper edge and the lower edge.
  • the first hole 50 has a substantially elliptical shape (a part of the ellipse) that is long in the axial direction of the rod 3 in a side view.
  • the opening 5 has a tapered shape that vertically expands as it goes to the front (the tip side) in a side view.
  • the holes 50, 51, 52 forming the opening 5 have the distances d1, d2, d3 increasing toward the front, and the most proximal end side among the plurality of holes 50, 51, 52.
  • the tops of the upper and lower edges of the first hole 50 of the first hole 50 are the lowest, and the tops of the upper and lower edges of the second holes 51 adjacent to the first hole 50 of the The tops of the upper and lower edges of the side third hole 52 are located at the highest position.
  • the stress generated in the narrowed portion 27 of each branch portion 20 and 21 increases, but the stress locally increases in the narrowed portion 27.
  • the narrowed portion 27 is easily damaged. This stress concentration is likely to occur in a portion (base portion) near the base end position of the opening 5, and in order to suppress the stress concentration in the base portion of the opening 5, it is effective to provide the base portion with a rounded shape.
  • the base of the opening 5 is rounded, stress is more likely to be concentrated as the radius of curvature is smaller. Therefore, it is preferable to increase the radius of curvature.
  • the base portion becomes too long in the vertical direction, and the narrowed portion 27 of each of the branch portions 20 and 21 becomes thin so that it is weakened and the stress is increased.
  • the outer shape of the first hole 50 which is the base portion in the opening 5
  • the narrowed portions 27 of the respective branch portions 20 and 21 are formed.
  • the radius of curvature of the upper edge and the lower edge of the base can be increased without reducing the wall thickness. Therefore, the stress concentration on the base of the opening 5 can be relaxed, and the maximum stress generated in the narrowed portion 27 of each of the branch portions 20 and 21 can be suppressed, so that the narrowed portion 27 is prevented from being damaged. be able to.
  • the stress concentrated in the first hole 50 which is the base of the opening 5
  • the stress was concentrated on the base of the opening 5 by being dispersed in the second and third holes 51 and 52. Therefore, in the present embodiment, the maximum stress generated in the narrowed portion 27 of each of the branched portions 20 and 21 can be suppressed more effectively, so that the narrowed portion 27 can be effectively prevented from being damaged.
  • the radius of curvature of the second and third holes 51, 52 adjacent to the first hole 50 is gradually reduced, the stress is likely to concentrate on the hole having a small radius of curvature. The stress is likely to be dispersed in the third holes 51 and 52, and the stress concentration on the first holes 50 can be alleviated more effectively.
  • the opening 5 has a taper shape that vertically expands as it goes forward, so that the second and third holes 51 adjacent to the first hole 50 are formed. It was confirmed that the stress was easily dispersed in the holes 52, 52, and the stress was applied to the holes 50, 51, 52 almost uniformly. Therefore, in the present embodiment, the maximum stress generated in the narrowed portion 27 of each of the branched portions 20 and 21 can be suppressed more effectively, so that the narrowed portion 27 can be prevented from being damaged even better.
  • the interbody cage 1 described above can be manufactured in a number of different sizes to allow good fit to the patient.
  • the intervertebral cage 1 having the above-mentioned configuration between the vertebral bodies of two adjacent vertebrae above and below the spine, as shown in FIG. 22, first, the pedicle screw system (not shown) After fixing the vertebral body 100 at an appropriate interbody height / angle and removing the degenerated intervertebral disc 101 and osteophytes, the intervertebral cage 1 is placed in the space of the removed intervertebral disc 101 between the upper and lower vertebral bodies 100. Is inserted (FIG. 22 (a)).
  • the respective branch portions 20 and 21 of the main body 2 are vertically separated from each other.
  • the handle 111 is turned to screw the male screw portion 33 of the rod 3 into the slider 4.
  • the slider 4 moves in the axial direction of the rod 3 toward the base end side (the base 22 side of the main body 2), and at that time, the contact surface 43 of the slider 4 causes the inclined surface 26A of each of the branch portions 20 and 21.
  • the bifurcations 20 and 21 undergo vertical bending deformation and are separated from each other, and the interbody cage 1 is expanded (FIG. 22 (b)).
  • the outer surfaces of the bifurcations 20 and 21 are in close contact with the upper and lower vertebral bodies 100 so that the plurality of protrusions 29 mesh with the upper and lower vertebral bodies 100.
  • the intervertebral body cage 1 is mounted between the upper and lower vertebral bodies 100 by adjusting the degree of dilation.
  • the interbody cage 1 can be opened up and down, and by adjusting an appropriate alignment of the degree of openness according to the patient, the interbody cage can be normally opened. Since it can be maintained at various heights and angles, it is possible to correct the spine (recovery and acquisition of lordosis angle) suitable for the patient. Further, the intervertebral body cage 1 reliably reinforces the intervertebral bodies and prevents the space between the vertebral bodies from being collapsed by the pressure received from the upper and lower vertebral bodies 100. Therefore, it is possible to prevent the prolongation of bone fusion and false joints. It is possible.
  • the interbody cage 1 of the present embodiment when each of the branched portions 20 and 21 is bent and deformed as the slider 4 moves, the stress generated in the narrowed portion 27 of each of the branched portions 20 and 21 is high.
  • the opening 5 by forming the opening 5 by arranging a plurality of holes 50, 51, 52 whose upper and lower edges form a convex curve, stress concentrated on the first hole 50, which is the base of the opening 5, is applied. It is possible to reduce the concentration of stress on the base of the opening 5 by being dispersed in the adjacent second and third holes 51 and 52.
  • the intervertebral body cage 1 can be more structurally stable. Can be included.
  • the rearmost hole 50 of the plurality of holes 50, 51, 52 has a shape of a part of an ellipse that is long in the axial direction of the rod 3 in a side view.
  • the plurality of holes 50, 51, 52 have a smaller radius of curvature of the convex curve of the upper edge and the lower edge of the plurality of holes 50, 51, 52, and (3) the opening 5 faces forward.
  • the interbody cage 1 of the present embodiment when the branch portions 20 and 21 of the main body 2 are vertically separated from each other, they are supported by the contact surfaces 43 of the slider 4 interposed therebetween in a separated state. ing.
  • the intervertebral body cage maintains stable performance between the vertebral bodies in a nearly normal manner, so that even if each of the bifurcations 20 and 21 receives pressure from the upper and lower vertebral bodies due to changes in body weight and body posture, the performance will deteriorate and There is a need for structural stability that can be maintained between the vertebral bodies without deformation.
  • the slider 4 is formed in a cylindrical shape like the interbody cage of Patent Document 1, the slider 4 makes line contact with the inclined surface 26A of each of the branching portions 20 and 21, and thus the slider with respect to the inclined surface 26A.
  • the contact area of 4 is small. Therefore, when each branching portion 20, 21 receives pressure from the upper and lower vertebral bodies after implantation, stress concentrates on the narrowed portion 27 at the root, and there is a risk of the narrowed portion 27 being damaged.
  • the interbody cage 1 of the present embodiment when pressure is applied to the bifurcations 20 and 21 from the upper and lower vertebral bodies after implantation, the inclined surfaces 26A of the bifurcations 20 and 21 are sliders.
  • the contact area of the slider 4 with respect to the inclined surface 26A can be increased.
  • the bifurcations 20 and 21 receive pressure from the upper and lower vertebral bodies when the intervertebral body cage 1 is reinforcing the intervertebral bodies.
  • the main body 2 and the slider 4 are made of polyetheretherketone (PEEK), so that the visibility of bone union is improved at the time of image diagnosis after surgery. Since it can be performed and has elasticity (hardness) almost equal to that of bone, the vertebra when the interbody cage 1 is mounted between the upper and lower vertebral bodies and receives pressure from the upper and lower vertebral bodies. It is possible to prevent the nerves from being depressed by sinking into the body. Further, since the respective branch portions 20 and 21 of the main body 2 are easily bent and deformed, the respective branch portions 20 and 21 can be favorably opened up and down by moving the slider 4 without making the thickness of the narrowed portion 27 too thin. You can
  • interbody cage 1 according to the embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the invention. ..
  • the opening 5 has a tapered shape that vertically expands toward the front, and the distance between the holes 50, 51, 52 forming the opening 5 is large.
  • the distances d1, d2, d3 increase toward the front, the opening 5 does not necessarily have to have a tapered shape, and the distance d1, between the holes 50, 51, 52 forming the opening 5 d2 and d3 may be the same.
  • the plurality of holes 50, 51, 52 forming the opening 5 have a smaller radius of curvature of the convex curve of the upper edge and the lower edge toward the front.
  • the radius of curvature does not necessarily have to be small, and may be large or small if all are different, or may be all the same.
  • the rearmost hole 50 of the plurality of holes 50, 51, 52 forming the opening 5 is a part of an ellipse elongated in the axial direction of the rod 3 in a side view. Although it has a shape (substantially elliptical shape), it does not necessarily have to have a substantially elliptical shape, and may have a substantially circular shape.
  • the rotational movement of the rod 3 is converted into the linear movement of the slider 4 by using the feed screw for axially moving the slider 4 with respect to the rod 3.
  • the mechanism for axially moving the slider 4 with respect to the rod 3 is not limited to the feed screw, and various known mechanisms can be used.
  • the outer side surfaces of the bifurcated portions 20 and 21 of the main body 2 are substantially parallel to each other, but they may be inclined so as to gradually separate toward the distal end.
  • the outer surface of each of the branch portions 20 and 21 may be opened in a V shape.
  • the slider 4 has the two contact surfaces 43 that respectively correspond to the inclined surfaces 26A of the pair of branch portions 20 and 21 of the main body 2 in a one-to-one relationship. 4 does not necessarily have to have the contact surface 43, and may be formed in a cylindrical shape, for example.

Landscapes

  • Health & Medical Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Neurology (AREA)
  • Orthopedic Medicine & Surgery (AREA)
  • Cardiology (AREA)
  • Oral & Maxillofacial Surgery (AREA)
  • Transplantation (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Vascular Medicine (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Prostheses (AREA)

Abstract

構造的安定性を有している椎体間ケージを提供する。 椎体間ケージ１は、上下に間隔をあけて設けられる一対の分岐部２０，２１を先端側に備えた本体２と、一対の分岐部２０，２１の間を延びるように本体２に設けられたロッド３と、一対の分岐部２０，２１を上下に離隔させるスライダー４であって、ロッド３に軸方向に移動可能に支持されるスライダー４と、を備え、一対の分岐部２０，２１は、互いに向き合いかつ先端に向けて次第に間隔が広がる傾斜面２６Ａをそれぞれ先端側に備え、スライダー４は、ロッド３の軸方向に移動する際に一対の分岐部２０，２１の傾斜面２６Ａ上を摺動し、一対の分岐部２０，２１は、厚みの窄まった狭窄部２７をそれぞれ基端側に備え、上下の狭窄部２７の間に側面視で上縁及び下縁が凸曲線をなす孔５０～５２をロッド３の軸方向に複数連ねて形作られた開口部５を有する。

Description

椎体間ケージ
　本発明は、腰部脊柱管狭窄症、脊椎変性すべり症、椎間板ヘルニア等の脊椎疾患の手術に際して、脊椎の上下に隣り合う２つの椎骨の椎体間にインプラントとして装着される椎体間ケージに関する。
　脊椎疾患の手術では、従来より、椎体間ケージを脊椎の上下に隣り合う２つの椎骨の椎体間に装着することにより、椎体間を正常に近い形に安定的に維持しながら補強する脊椎固定術が行われている。
　特許文献１には、開大式の椎体間ケージが開示されている。特許文献１の椎体間ケージは、スリットにより上下に分離される一対の分岐部を備えた本体と、スリットに沿って延びるように本体に設けられたスクリューと、スクリューがねじ込まれた円筒状のローラとで構成されている。特許文献１の椎体間ケージは、スクリューの回転によりローラがスクリューの軸方向に移動するが、このときローラが各分岐部の先端側の斜めの支承面上を摺動して各分岐部を押し上げ又は押し下げることで各分岐部が互いに離隔し、椎体間ケージが開大する。各分岐部は、基端側にスリットに連なる開口部を有しており、開口部の上下の間隔が大きいことで、各分岐部は、厚みの窄まった狭窄部を基端側に含んでいる。この狭窄部により、各分岐部は、ローラの移動に伴い互いに離隔するように変形する際に柔軟に曲げ変形することが可能となっている。
　脊椎の前弯角は個人差や部位による差があるため、椎体間ケージを装着する椎体間の高さ・角度に応じて椎体間ケージの開大度合いを調整することで、椎体間ケージによって患者に適した椎体間の補強が可能である。
特許第２６６９３７９号公報
　特許文献１の椎体間ケージでは、各分岐部がローラの移動に伴い曲げ変形した際に、各分岐部の狭窄部に生じる応力が高くなる。各分岐部の狭窄部は、各分岐部を上下に開きやすくするために厚みが窄められて肉薄となっていることから脆弱である。よって、狭窄部において局所的に応力が増大する応力集中が起きると、狭窄部が破損しやすくなる。特許文献１の椎体間ケージの開口部の形状では、各分岐部の狭窄部に局所的に応力が集中するため、特許文献１の椎体間ケージは、構造的に安定ではなく、この点で改良の余地がある。
　本発明は、上記課題を解決するためになされたものであり、構造的安定性を有している椎体間ケージを提供することを目的とする。
　本発明の椎体間ケージは、脊椎の隣り合う椎体の間に装着されるものであって、上下に間隔をあけて設けられる一対の分岐部を先端側に備えた本体と、一対の前記分岐部の間を延びるように前記本体に設けられたロッドと、一対の前記分岐部を上下に離隔させるスライダーであって、前記ロッドに軸方向に移動可能に支持されるスライダーと、を備え、一対の前記分岐部は、互いに向き合いかつ先端に向けて次第に間隔が広がる傾斜面をそれぞれ先端側に備え、前記スライダーは、前記ロッドの軸方向に移動する際に一対の前記分岐部の傾斜面上を摺動し、一対の前記分岐部は、厚みの窄まった狭窄部をそれぞれ基端側に備え、上下の前記狭窄部の間に側面視で上縁及び下縁が凸曲線をなす孔を前記ロッドの軸方向に複数連ねて形作られた開口部を有することを特徴としている。
　本発明の椎体間ケージの好ましい実施態様においては、前記スライダーは、一対の前記分岐部の傾斜面とそれぞれ一対一で対応する２つの当接面を備え、２つの前記当接面は、前記スライダーが前記ロッドの軸方向に移動する際に対応する前記傾斜面上を摺動する。
　本発明の椎体間ケージの好ましい実施態様においては、２つの前記当接面は、一対の前記分岐部が上下の椎体より圧力を受けた際に対応する前記傾斜面と面接触する。
　本発明の椎体間ケージの好ましい実施態様においては、複数の前記孔の最も基端側の孔は、前記ロッドの軸方向に長い楕円の一部の形状を呈している。
　本発明の椎体間ケージの好ましい実施態様においては、複数の前記孔は、先端側に向かうに連れて前記凸曲線の曲率半径が小さい。
　本発明の椎体間ケージの好ましい実施態様においては、前記開口部は、側面視で先端側に向かうに連れて上下に拡大するテーパ状を呈している。
　本発明の椎体間ケージの好ましい実施態様においては、前記本体及び前記スライダーが生体親和性を有する材料からなる。
　本発明の椎体間ケージによれば、スライダーがロッドの軸方向を移動することで本体の各分岐部の傾斜面上を摺動し、傾斜面をそれぞれ押し上げるないしは押し下げて、各分岐部を先端側が上下に開くように変形させることにより、各分岐部が上下に離隔し、椎体間ケージが開大する。患者に応じて椎体間ケージの開大度合いを調整することで、椎体間を正常な高さ・角度に調節することができるので、患者に適した脊椎の矯正（前弯角の回復・獲得）が可能である。また、椎体間ケージにより椎体間が確実に補強され、上下の椎体から受ける圧力により椎体間がつぶされることが防止されるので、骨癒合遷延・偽関節を防止することも可能である。
　また、本発明の椎体間ケージによれば、各分岐部がスライダーの移動に伴い曲げ変形した際には、各分岐部の狭窄部に生じる応力が高くなり、この応力は、開口部の基端位置近くの部分において集中しやすいが、開口部を複数の孔を連ねて形成することで、開口部の基端位置にあたる孔に集中する応力を隣接する孔に分散することができ、開口部の基端位置にあたる孔への応力集中を緩和することができる。そのため、各分岐部の狭窄部に生じる最大応力を抑制することができるので、狭窄部が破損することを良好に防止することができる。よって、構造的安定性を有する椎体間ケージを提供することができる。
図１は椎体間ケージの斜視図である。 図２は椎体間ケージの斜視図である。 図３は椎体間ケージの平面図である。 図４は椎体間ケージの側面図である。 図５は椎体間ケージの正面図である。 図６は椎体間ケージの背面図である。 図７は椎体間ケージの縦断面図である。 図８は本体の斜視図である。 図９は本体の斜視図である。 図１０は本体の平面図である。 図１１は本体の側面図である。 図１２は本体の背面図である。 図１３は本体の断面図である。 図１４はロッドの斜視図である。 図１５はロッドの側面図である。 図１６はスライダーの斜視図である。 図１７はスライダーの斜視図である。 図１８はスライダーの平面図である。 図１９はスライダーの側面図である。 図２０は開大した状態の椎体間ケージの斜視図である。 図２１は開大した状態の椎体間ケージの断面図である。 図２２は椎体間ケージを椎骨の間に装着した状態を示す。
　以下、本発明の実施形態について添付図面を参照して説明する。本発明の椎体間ケージは、腰部脊柱管狭窄症、脊椎変性すべり症、椎間板ヘルニア等の脊椎疾患の手術に際して、脊椎の矯正や移植骨による骨癒合の促進等を目的に、インプラントとして脊椎の上下に隣り合う２つの椎骨の椎体間に装着して椎体間が正常に近い高さ・角度に安定的に維持されるよう椎体間を補強するためのものである。
　図１～図７は、本実施形態の椎体間ケージ１を示している。椎体間ケージ１は、一対の分岐部２０，２１を先端側に備えた本体２と、本体２に内蔵されたロッド３と、ロッド３の先端側に軸方向に移動可能に支持されたスライダー４とを備えている。なお、以下の説明においては、長手形状を呈する椎体間ケージ１の長さ方向について、スライダー４側を前側（先端側）と規定し、その反対側（本体２の基部２２側）を後ろ側（基端側）と規定する。
　本体２は、生体親和性を有する材料により形成されている。生体親和性を有する材料としては、本体２が良好な耐久性を有するために、チタン、チタン合金、ステンレス鋼等の金属材料、又はポリエーテルエーテルケトン（ＰＥＥＫ）、ポリプロピレン（ＰＰ）、ポリエチレンテレフタレート（ＰＥＴ）等のプラスチック材料を好ましく例示することができ、その中でも、手術後の画像診断の際に骨癒合の視認性が良好であるＰＥＥＫを最も好ましく例示することができる。ＰＥＥＫは、さらに骨とほぼ同等の弾性（硬さ）を有しているため、椎体間ケージ１が上下の椎体の間に装着された状態で上下の椎体から圧力を受けたときに椎体に対して沈みこんで神経を圧迫することを防止できる。
　本体２は、図１～図７に加えて図８～図１３に示すように、長さ方向に延びる一対の分岐部２０，２１と、両分岐部２０，２１を連結する基部２２とを備えた略Ｕ字型の構造のものである。基部２２は、後端面に座ぐり加工が施されることにより長さ方向に延びる有底かつ断面視円形状の凹部２３が形成されている。凹部２３には、ロッド３の頭部３０が回転自在に嵌め込まれる。また、凹部２３の底には、ロッド３の棒状部３１が挿し通される挿通穴２４が形成されている。挿通穴２４はロッド３の頭部３０よりは外形が小さく、ロッド３の頭部３０は挿通穴２４を通過せずに凹部２３の底に突き当たる。
　一対の分岐部２０，２１は、上下に間隔をあけて設けられている。一対の分岐部２０，２１は、基端（後ろ側の端）が基部２２に一体に連なっており、先端（前側の端）側が上下に開くように変形可能である。
　一対の分岐部２０，２１は、先端に向けて次第に厚みが小さくなるテーパ部２５を先端側に含んでいる。テーパ部２５は、内側面（分岐部２０では下面、分岐部２１では上面）が断面視において直線状に傾斜する傾斜面２６Ａをなしている。各分岐部２０，２１の傾斜面２６Ａは、互いに向き合うとともに先端に向けて次第に離れるように間隔が広がっており、Ｖ字状を呈している。各分岐部２０，２１の傾斜面２６Ａの傾斜角度は、傾斜面２６Ａの後ろ側に隣接する平面２６Ｂに対して１５°以上３５°以下であることが好ましく、２０°以上３０°以下であることがより好ましい。
　一対の分岐部２０，２１には、テーパ部２５の幅方向の両側縁（左右の側縁）に一対のガイド壁２８が設けられている。両ガイド壁２８は、スライダー４の離隔部４２を挟むように離隔部４２の左右の側面にそれぞれ隣接して配置されている。両ガイド壁２８は、スライダー４がロッド３の軸方向に沿って移動する際にスライダー４がロッド３の周方向に回転することなく真っ直ぐ軸方向に移動するようにガイドする機能を果たす。
　一対の分岐部２０，２１の外側面（分岐部２０では上面、分岐部２１では下面）は、互いに略平行であり、その長さ方向の中央が外側に向けて凸をなするように湾曲するアーチ状を呈している。一対の分岐部２０，２１の外側面には、鋸歯状の複数の突起２９が長さ方向に間隔をあけて設けられている。この複数の突起２９は、椎体間ケージ１が椎体間に装着された際に上下の椎体や椎間板に噛み込むことで椎体間ケージ１を椎体間に定着させる機能を果たす。
　一対の分岐部２０，２１には、幅方向の中央に上下方向に貫通するオリフィス５３が形成されている。オリフィス５３は、椎体間において骨修復を良好に行うための移植骨の破片を収納するためのものであり、各分岐部２０，２１の長さ方向に長い長孔状を呈している。
　ロッド３は、生体親和性を有する材料により形成されている。生体親和性を有する材料としては、本体２が良好な耐久性を有するために、チタン、チタン合金、ステンレス鋼等の金属材料、又はポリエーテルエーテルケトン（ＰＥＥＫ）、ポリプロピレン（ＰＰ）、ポリエチレンテレフタレート（ＰＥＴ）等のプラスチック材料を好ましく例にすることができ、その中でも、チタン合金を最も好ましく例示することができる。
　ロッド３は、図１～図７に加えて図１４～図１５に示すように、各分岐部２０，２１の間を長さ方向に延びるように本体２に設けられており、ロッド３の軸方向は各分岐部２０，２１の長さ方向と同方向を向いている。ロッド３は、本実施形態ではボルトが用いられており、例えば六角穴付きの頭部３０と、頭部３０から突き出た棒状部３１と、棒状部３１の基端側に頭部３０と所定間隔をあけて設けられた鍔部３２とを備えている。
　頭部３０は、本体２の基部２２の凹部２３内に支持されている。棒状部３１は本体２の一対の分岐部２０，２１の間に突き出て各分岐部２０，２１の間を先端付近まで延びている。棒状部３１の先端側の外周面には、後述するスライダー４の雌ネジ部４１に螺合する雄ネジ部３３が形成されている。鍔部３２は、頭部３０との間で凹部２３の底を挟むことで、ロッド３の軸方向の移動を規制するストッパーとしての機能を果たす。
　スライダー４は、生体親和性を有する材料により形成されている。生体親和性を有する材料としては、スライダー４が良好な耐久性を有するために、チタン、チタン合金、ステンレス鋼等の金属材料、又はポリエーテルエーテルケトン（ＰＥＥＫ）、ポリプロピレン（ＰＰ）、ポリエチレンテレフタレート（ＰＥＴ）等のプラスチック材料を好ましく例示することができ、その中でも、手術後の画像診断の際に骨癒合の視認性が良好であるとともに骨の弾性に近似した弾性を有するＰＥＥＫを最も好ましく例示することができる。
　スライダー４は、図１～図７に加えて図１６～図１９に示すように、内部に後端面から前端面まで貫通した貫通穴４０が形成されており、貫通穴４０を形作る内壁面には雌ネジ部４１が形成されている。この雌ネジ部４１にロッド３の雄ネジ部３３が螺合されることでスライダー４はロッド３に支持されるとともに、ロッド３の回転により雄ネジ部３３がねじ込まれていくことでスライダー４はロッド３の軸方向に基端側（頭部３０側）に向かって移動可能とされている。
　スライダー４は、ロッド３の軸方向に基端側に向かって移動することにより本体２の一対の分岐部２０，２１を上下に離隔させる離隔部４２を備えている。離隔部４２は、断面視で略等脚台形状を呈しており、前記略等脚台形の斜辺に当たる位置に、一対の分岐部２０，２１の傾斜面２６Ａとそれぞれ一対一で対応する上下２つの当接面４３を備えている。
　各当接面４３は、断面視において直線状に傾斜しており、スライダー４の前端面に向けて次第に離れるように広がっていて、Ｖ字状を呈している。各当接面４３の傾斜角度は、対応する傾斜面２６Ａの傾斜角度よりも大きく急傾斜である。具体的には、各当接面４３の傾斜角度は、当接面４３に隣接するとともに、離隔部４２の後端側に連設された軸部４４の上下の平面４５に対して２０°以上４０°以下であることが好ましく、２５°以上３５°以下であることがより好ましい。
　この２つの当接面４３は、椎体間ケージ１が開大する前の初期状態においては、本体２の一対の分岐部２０，２１の対応する傾斜面２６Ａと少なくとも一部同士が当接している。そして、図２０及び図２１に示すように、スライダー４がロッド３の軸方向に後端側に向かって移動すると、各当接面４３は、対応する傾斜面２６Ａ上を摺動する。その際に、各当接面４３が対応する傾斜面２６Ａをそれぞれ押し上げるないしは押し下げて、一対の分岐部２０，２１を先端側が上下に開くように変形させることで、一対の分岐部２０，２１が平行な状態から上下に離隔し、その結果、椎体間ケージ１が開大する。脊椎の前弯角は個人差や部位による差があるため、椎体間ケージ１が上下に開大可能であることで、椎体間ケージ１を装着する椎体間の高さ・角度に応じて椎体間ケージ１の開大度合いを調整することにより、椎体間ケージ１によって患者に適した椎体間の補強が可能である。
　スライダー４は、椎体間ケージ１が開大する前の初期状態において、ロッド３に対する軸方向の先端側への移動を規制する一対の位置決め突起４６を備えている。一対の位置決め突起４６は、軸部４４の上下の平面４５からそれぞれ突き出ている。椎体間ケージ１が開大する前の初期状態において、各位置決め突起４６が、本体２の一対の分岐部２０，２１のオリフィス５３を形作る開口縁部の長さ方向の前端部に突き当たることで、本体２に対するスライダー４の位置決めがなされ、ロッド３に対してスライダー４が軸方向の先端側へ移動することが規制されている。
　一対の分岐部２０，２１の上下の間隔は、図１１及び図１３に示すように、本体２の基部２２に近接する基端位置から所定の長さにわたって上下に拡大しており、基端側に間隔が上下に大きい開口部５を備えている。この開口部５により、本体２の一対の分岐部２０，２１は、厚みの窄まった狭窄部２７を基部２２側（基端側）に含んでいる。この狭窄部２７により、一対の分岐部２０，２１は、スライダー４の移動に伴いその先端側が上下に開くように変形する際に柔軟に曲げ変形することが可能であり、無理なく良好に一対の分岐部２０，２１を互いに離隔させることができる。
　開口部５は、本実施形態では、複数（本実施形態では３つ）の孔５０，５１，５２を長さ方向（ロッド３の軸方向）に連ねることで形作られている。複数の孔５０，５１，５２は、側面視において上縁及び下縁が凸曲線をなしており、隣接する孔５０，５１又は５２の上縁の凸曲線同士及び下縁の凸曲線同士がそれぞれ滑らかに接続されることで、上下の狭窄部２７の間において、開口部５は側面視で瓢箪形状を呈している。
　複数の孔５０，５１，５２は、上縁及び下縁の凸曲線の曲率半径がそれぞれ異なっており、各分岐部２０，２１の先端側に向かうに連れて曲率半径が小さくなっている。つまり、複数の孔５０，５１，５２のうち、基端位置に近い最も基端側（最後方）の第１の孔５０の曲率半径が最も大きく、第１の孔５０に隣接する第２の孔５１の曲率半径が次に大きく、基端位置から遠い最も先端側（最前方）の第３の孔５２の曲率半径が最も小さい。第１の孔５０の上縁及び下縁は、第２の孔５１が隣接する側と反対側において、上縁及び下縁の凸曲線よりも曲率半径の小さい凸曲線により滑らかに繋がれており、第１の孔５０は側面視でロッド３の軸方向に長い略楕円形状（楕円の一部の形状）を呈している。
　開口部５は、本実施形態では、側面視で前方（先端側）に向かうに連れて上下に拡大するテーパ状を呈している。つまり、開口部５を構成する各孔５０，５１，５２は、前方に向かうに連れて間隔ｄ１，ｄ２，ｄ３が大きくなっており、複数の孔５０，５１，５２のうち、最も基端側の第１の孔５０の上縁及び下縁の頂部が最も低く位置し、第１の孔５０に隣接する第２の孔５１の上縁及び下縁の頂部が次に低く位置し、最も先端側の第３の孔５２の上縁及び下縁の頂部が最も高く位置している。
　一対の分岐部２０，２１がスライダー４の移動に伴い曲げ変形した際には、各分岐部２０，２１の狭窄部２７に生じる応力が高くなるが、狭窄部２７において局所的に応力が増大する応力集中が起きると、狭窄部２７が破損しやすくなる。この応力集中は、開口部５の基端位置近くの部分（基部）において起こりやすく、開口部５の基部における応力集中を抑制するためには、当該基部に丸みを設けることが有効である。しかし、開口部５の基部に丸みを設けるにあたって、曲率半径が小さいほど応力が集中しやすくなるため、曲率半径を大きくすることが好ましいものの、曲率半径を大きくし過ぎると開口部５の基部が側面視で円形状を呈している場合には当該基部が上下に長くなり過ぎることで、各分岐部２０，２１の狭窄部２７が肉薄となることにより脆弱化して逆に応力が高くなる。
　そこで、本実施形態では、開口部５において基部にあたる第１の孔５０の外形を側面視でロッド３の軸方向に長い略楕円形状とすることで、各分岐部２０，２１の狭窄部２７を肉薄とすることなく、当該基部の上縁及び下縁の曲率半径を大きくすることができる。よって、開口部５の基部への応力集中を緩和することができ、各分岐部２０，２１の狭窄部２７に生じる最大応力を抑制することができるので、狭窄部２７が破損することを防止することができる。
　また、本発明者の鋭意研究の結果、開口部５を複数の孔５０，５１，５２を連ねて形成することで、開口部５の基部にあたる第１の孔５０に集中する応力を隣接する第２及び第３の孔５１，５２に分散され、開口部５の基部への応力集中が緩和されることが確認された。よって、本実施形態では、各分岐部２０，２１の狭窄部２７に生じる最大応力をより効果的に抑制することができるので、狭窄部２７が破損することを良好に防止することができる。このとき、第１の孔５０に隣接する第２及び第３の孔５１，５２の曲率半径が次第に小さくなっていることで、応力は曲率半径が小さい孔に集中しやすいため、第２及び第３の孔５１，５２に応力が分散しやすくなり、第１の孔５０への応力集中をより効果的に緩和することができる。
　さらに、本発明者の鋭意研究の結果、開口部５が前方に向かうに連れて上下に拡大するテーパ状を呈していることで、第１の孔５０に隣接する第２及び第３の孔５１，５２に応力が分散しやすくなり、各孔５０，５１，５２にほぼ均等に応力がかかっていることが確認された。よって、本実施形態では、各分岐部２０，２１の狭窄部２７に生じる最大応力をより効果的に抑制することができるので、狭窄部２７が破損することをさらに良好に防止することができる。
　上述した椎体間ケージ１は、患者に対して良好に適合可能とするために複数の種々のサイズで製造することができる。
　次に、上述した構成の椎体間ケージ１を脊椎の上下に隣り合う２つの椎骨の椎体間に装着するには、図２２に示すように、まず、図示しないペディクルスクリューシステムにより上下の椎体１００を適切な椎体間高さ・角度で固定して、変性した椎間板１０１や骨棘を取り除いた後、上下の椎体１００の間の取り除いた椎間板１０１のスペースに椎体間ケージ１を挿入する（図２２（ａ））。
　そして、ネジ回し１１０を用いて本体２内のロッド３を遠隔操作により回転させることで、本体２の各分岐部２０，２１を上下に互いに離隔させる。具体的には、ネジ回し１１０の先端のアダプタをロッド３の頭部３０内に嵌め合わせた後、把手１１１を回すことで、スライダー４内にロッド３の雄ネジ部３３をねじ込む。これにより、スライダー４がロッド３の軸方向を基端側（本体２の基部２２側）に向かって移動し、その際にスライダー４の当接面４３が各分岐部２０，２１の傾斜面２６Ａ上を摺動することで、各分岐部２０，２１がそれぞれ上下に曲げ変形を受けて互いに離隔して、椎体間ケージ１が開大する（図２２（ｂ））。
　ネジ回し１１０によるロッド３の回転を制御して、各分岐部２０，２１の外側面が上下の椎体１００に密着して複数の突起２９が上下の椎体１００と噛み合うよう椎体間ケージ１の開大度合いを調整することで、椎体間ケージ１が上下の椎体１００の間に装着される。
　本実施形態の椎体間ケージ１によれば、椎体間ケージ１が上下に開大可能であり、患者に応じて開大度合いの適切なアラインメントの調節を行うことで、椎体間を正常な高さ・角度に維持することができるので、患者に適した脊椎の矯正（前弯角の回復・獲得）が可能である。また、椎体間ケージ１により椎体間が確実に補強され、上下の椎体１００から受ける圧力により椎体間がつぶされることが防止されるので、骨癒合遷延・偽関節を防止することも可能である。
　また、本実施形態の椎体間ケージ１によれば、各分岐部２０，２１がスライダー４の移動に伴い曲げ変形した際には、各分岐部２０，２１の狭窄部２７に生じる応力が高くなるが、開口部５を、上縁及び下縁が凸曲線をなす複数の孔５０，５１，５２を連ねて形成することで、開口部５の基部にあたる第１の孔５０に集中する応力を隣接する第２及び第３の孔５１，５２に分散して、開口部５の基部に応力が集中することを緩和できる。よって、狭窄部２７において局所的に応力が増大する応力集中を防止することができるので、狭窄部２７が破損することを良好に防止することができ、椎体間ケージ１をより構造的安定性を有するものとすることができる。
　なお、本実施形態の椎体間ケージ１によれば、（１）複数の孔５０，５１，５２の最後方の孔５０が側面視においてロッド３の軸方向に長い楕円の一部の形状を呈していること、（２）複数の孔５０，５１，５２は、前方に向かうに連れて上縁及び下縁の凸曲線の曲率半径が小さいこと、（３）開口部５は、前方に向かうに連れて上下に拡大するテーパ状を呈していることで、それぞれ開口部５の基部に応力が集中することをより効果的に緩和できる。よって、狭窄部２７が破損することをさらに良好に防止することができる。
　また、本実施形態の椎体間ケージ１によれば、本体２の各分岐部２０，２１が上下に離隔した際、間に介在するスライダー４の各当接面４３により離隔した状態で支持されている。椎体間ケージは、椎体間を正常に近い形で安定的に維持するために、各分岐部２０，２１が体重や体勢の変化によって上下の椎体から圧力を受けても性能の低下や変形を起こさずに椎体間を維持できる構造的安定性が必要とされる。ここで、スライダー４が特許文献１の椎体間ケージのように円筒状に形成されていると、スライダー４が各分岐部２０，２１の傾斜面２６Ａに線接触するため、傾斜面２６Ａに対するスライダー４の接触面積が小さい。そのため、埋植後に各分岐部２０，２１が上下の椎体から圧力を受けた際に根元の狭窄部２７に応力が集中することから、狭窄部２７が破損するおそれがある。これに対して、本実施形態の椎体間ケージ１では、埋植後に上下の椎体から各分岐部２０，２１が圧力を受けた際に、各分岐部２０，２１の傾斜面２６Ａがスライダー４の対応する当接面４３と面接触することにより、傾斜面２６Ａに対するスライダー４の接触面積を大きくすることができる。このように、スライダー４が各分岐部２０，２１を面で受けるため、椎体間ケージ１により椎体間を補強している際に各分岐部２０，２１が上下の椎体から圧力を受けても、各分岐部２０，２１の根元の狭窄部２７に応力が集中することが緩和され、狭窄部２７の破損を防止することができる。よって、構造的安定性を有する椎体間ケージ１を提供することができる。
　また、本実施形態の椎体間ケージ１によれば、本体２及びスライダー４がポリエーテルエーテルケトン（ＰＥＥＫ）製であることで、手術後の画像診断の際に骨癒合の視認性を良好に行うことができるうえ、骨とほぼ同等の弾性（硬さ）を有するので、椎体間ケージ１が上下の椎体の間に装着された状態で上下の椎体から圧力を受けたときに椎体に対して沈みこんで神経を圧迫することを防止できる。さらに、本体２の各分岐部２０，２１が曲げ変形しやすいので、狭窄部２７の厚みを薄くし過ぎなくても、スライダー４の移動により各分岐部２０，２１を良好に上下に開かせることができる。
　以上、本発明の一実施形態に係る椎体間ケージ１について説明したが、本発明は上述した実施形態に限定されるものではなく、その趣旨を逸脱しない限りにおいて、種々の変更が可能である。
　例えば、上記実施形態の椎体間ケージ１では、開口部５は、前方に向かうに連れて上下に拡大するテーパ状を呈しており、開口部５を構成する各孔５０，５１，５２の間隔ｄ１，ｄ２，ｄ３が前方に向かうに連れて大きくなっているが、必ずしも開口部５はテーパ状を呈している必要はなく、開口部５を構成する各孔５０，５１，５２の間隔ｄ１，ｄ２，ｄ３が同じであってもよい。
　また、上記実施形態の椎体間ケージ１では、開口部５を構成する複数の孔５０，５１，５２は、前方に向かうに連れて上縁及び下縁の凸曲線の曲率半径が小さくなっているが、必ずしも曲率半径は小さくなっている必要はなく、全てが異なっていれば大きかったり小さかったりしてもよく、また全てが同じであってもよい。
　また、上記実施形態の椎体間ケージ１では、開口部５を構成する複数の孔５０，５１，５２の最後方の孔５０は、側面視においてロッド３の軸方向に長い楕円の一部の形状（略楕円形状）を呈しているが、必ずしも略楕円形状を呈している必要はなく、略円形状を呈していてもよい。
　また、上記実施形態の椎体間ケージ１では、ロッド３に対してスライダー４を軸方向に移動させるために送りねじを用いてロッド３の回転運動をスライダー４の直線運動に変換しているが、ロッド３に対してスライダー４を軸方向に移動させる機構としては送りねじに限定されるものではなく、公知の種々の機構を用いることができる。
　また、上記実施形態の椎体間ケージ１では、本体２の各分岐部２０，２１の外側面は、互いに略平行であるが、先端に向けて次第に離れるように傾斜していてもよく、開大前の状態で、各分岐部２０，２１の外側面がＶ字に開いていてもよい。
　また、上記実施形態の椎体間ケージ１では、スライダー４が本体２の一対の分岐部２０，２１の傾斜面２６Ａとそれぞれ一対一で対応する２つの当接面４３を備えているが、スライダー４は必ずしも当接面４３を備えている必要はなく、例えば円筒状に形成されていてもよい。
　１　　　椎体間ケージ
　２　　　本体
　３　　　ロッド
　４　　　スライダー
　５　　　開口部
　２０　　分岐部
　２１　　分岐部
　２６Ａ　傾斜面
　４３　　当接面
　５０　第１の孔
　５１　第２の孔
　５２　第３の孔

Claims (7)

  1. 　脊椎の隣り合う椎体の間に装着される椎体間ケージであって、
    　上下に間隔をあけて設けられる一対の分岐部を先端側に備えた本体と、
    　一対の前記分岐部の間を延びるように前記本体に設けられたロッドと、
    　一対の前記分岐部を上下に離隔させるスライダーであって、前記ロッドに軸方向に移動可能に支持されるスライダーと、を備え、
    　一対の前記分岐部は、互いに向き合いかつ先端に向けて次第に間隔が広がる傾斜面をそれぞれ先端側に備え、
    　前記スライダーは、前記ロッドの軸方向に移動する際に一対の前記分岐部の傾斜面上を摺動し、
    　一対の前記分岐部は、厚みの窄まった狭窄部をそれぞれ基端側に備え、上下の前記狭窄部の間に側面視で上縁及び下縁が凸曲線をなす孔を前記ロッドの軸方向に複数連ねて形作られた開口部を有する、椎体間ケージ。
  2. 　前記スライダーは、一対の前記分岐部の傾斜面とそれぞれ一対一で対応する２つの当接面を備え、
    　２つの前記当接面は、前記スライダーが前記ロッドの軸方向に移動する際に対応する前記傾斜面上を摺動する、請求項１に記載の椎体間ケージ。
  3. 　２つの前記当接面は、一対の前記分岐部が上下の椎体より圧力を受けた際に対応する前記傾斜面と面接触する、請求項２に記載の椎体間ケージ。
  4. 　複数の前記孔の最も基端側の孔は、前記ロッドの軸方向に長い楕円の一部の形状を呈している、請求項１～３のいずれかに記載の椎体間ケージ。
  5. 　複数の前記孔は、先端側に向かうに連れて前記凸曲線の曲率半径が小さい、請求項１～４のいずれかに記載の椎体間ケージ。
  6. 　前記開口部は、側面視で先端側に向かうに連れて上下に拡大するテーパ状を呈している、請求項１～５のいずれかに記載の椎体間ケージ。
  7. 　前記本体及び前記スライダーが生体親和性を有する材料からなる、請求項１～６のいずれかに記載の椎体間ケージ。
PCT/JP2019/042133 2018-11-09 2019-10-28 椎体間ケージ WO2020095745A1 (ja)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US17/292,202 US12004962B2 (en) 2018-11-09 2019-10-28 Interbody cage
EP19883048.1A EP3878412A4 (en) 2018-11-09 2019-10-28 INTERBODY CAGE

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2018211147A JP6820608B2 (ja) 2018-11-09 2018-11-09 椎体間ケージ
JP2018-211147 2018-11-09

Publications (1)

Publication Number Publication Date
WO2020095745A1 true WO2020095745A1 (ja) 2020-05-14

Family

ID=70611147

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2019/042133 WO2020095745A1 (ja) 2018-11-09 2019-10-28 椎体間ケージ

Country Status (4)

Country Link
US (1) US12004962B2 (ja)
EP (1) EP3878412A4 (ja)
JP (1) JP6820608B2 (ja)
WO (1) WO2020095745A1 (ja)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114769955A (zh) * 2022-04-22 2022-07-22 北京惠水四方科技有限公司 一种可快速上料的钢筋笼生产装置

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2669379B2 (ja) * 1994-01-26 1997-10-27 バイオマート 椎骨体腔壁間ケージ
KR100953930B1 (ko) * 2009-04-17 2010-04-22 주식회사 지에스메디칼 확장 가능한 척추 임플란트용 케이지 및 케이지 홀더

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3941028A (en) * 1975-03-06 1976-03-02 The Eastern Company Mine roof expansion anchor
FR2782632B1 (fr) * 1998-08-28 2000-12-29 Materiel Orthopedique En Abreg Cage de fusion intersomatique expansible
US6821298B1 (en) * 2000-04-18 2004-11-23 Roger P. Jackson Anterior expandable spinal fusion cage system
US7678148B2 (en) 2004-07-23 2010-03-16 Warsaw Orthopedic, Inc. Expandable spinal implant having interlocking geometry for structural support
US7655046B2 (en) * 2005-01-20 2010-02-02 Warsaw Orthopedic, Inc. Expandable spinal fusion cage and associated instrumentation
US10842644B2 (en) * 2010-09-03 2020-11-24 Globus Medical, Inc. Expandable fusion device and method of installation thereof
US9125701B2 (en) * 2012-10-11 2015-09-08 Zimmer Gmbh Subtalar implant
WO2014088521A2 (en) * 2012-12-06 2014-06-12 Kamil Bal Intervertebral expandable cage system and its instrument
US10039650B2 (en) * 2013-03-15 2018-08-07 In Queue Innovations, Llc Expandable fusion cage system

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2669379B2 (ja) * 1994-01-26 1997-10-27 バイオマート 椎骨体腔壁間ケージ
KR100953930B1 (ko) * 2009-04-17 2010-04-22 주식회사 지에스메디칼 확장 가능한 척추 임플란트용 케이지 및 케이지 홀더

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP3878412A4 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114769955A (zh) * 2022-04-22 2022-07-22 北京惠水四方科技有限公司 一种可快速上料的钢筋笼生产装置
CN114769955B (zh) * 2022-04-22 2023-10-13 烟台凤元新材料有限公司 一种可快速上料的钢筋笼生产装置

Also Published As

Publication number Publication date
EP3878412A4 (en) 2022-08-10
EP3878412A1 (en) 2021-09-15
JP2020074999A (ja) 2020-05-21
US20210386554A1 (en) 2021-12-16
JP6820608B2 (ja) 2021-01-27
US12004962B2 (en) 2024-06-11

Similar Documents

Publication Publication Date Title
US10130486B2 (en) Interbody implantation system and method
US11911288B2 (en) Stand alone interbody spinal system
US8187303B2 (en) Anti-rotation fixation element for spinal prostheses
US11337824B2 (en) Stabilizing vertebrae with articulating implants
CN102256570B (zh) 椎骨椎体间的间隔件和连接板组件
US8460388B2 (en) Spinal interbody device
US9486324B2 (en) Apparatus and method for stabilizing adjacent bone portions
US20170100255A1 (en) Intervertebral cage for lateral approach
US20160296342A1 (en) Flexible spinal fixation device
EP3027147B1 (en) Artificial disc devices and related methods of use
US11752003B2 (en) Expandable interbody spacer
WO2020095745A1 (ja) 椎体間ケージ
US20220015919A1 (en) Intervertebral devices
US11129728B1 (en) Surgically implantable joint spacer
US11357640B2 (en) Expandable interbody fusions devices
KR20210029373A (ko) 척추 교정 장치

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 19883048

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

ENP Entry into the national phase

Ref document number: 2019883048

Country of ref document: EP

Effective date: 20210609