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
• • 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
  • A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
  • A61B17/70—Spinal positioners or stabilisers ; Bone stabilisers comprising fluid filler in an implant
• • 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
  • A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
  • A61B17/70—Spinal positioners or stabilisers ; Bone stabilisers comprising fluid filler in an implant
  • A61B17/7049—Connectors, not bearing on the vertebrae, for linking longitudinal elements together
  • A61B17/705—Connectors, not bearing on the vertebrae, for linking longitudinal elements together for linking adjacent ends of longitudinal elements
• • 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
  • A61F2/4425—Intervertebral or spinal discs, e.g. resilient made of articulated components

Definitions

• Spinal rods are often used in the surgical treatment of spinal disorders such as degenerative disc disease, disc herniations, scoliosis or other curvature abnormalities, and fractures. Different types of surgical treatments are used. In some cases, spinal fusion is indicated to inhibit relative motion between vertebral bodies. In other cases, dynamic implants are used to preserve motion between vertebral bodies. For either type of surgical treatment, spinal rods may be attached to the exterior of two or more vertebrae, whether it is at a posterior, anterior, or lateral side of the vertebrae. In other embodiments, spinal rods are attached to the vertebrae without the use of dynamic implants or spinal fusion.
• Spinal rods may provide a stable, rigid column that encourages bones to fuse after spinal- fusion surgery. Further, the rods may redirect stresses over a wider area away from a damaged or defective region. Also, a rigid rod may restore the spine to its proper alignment. In some cases, a flexible rod may be appropriate. Flexible rods may provide some advantages over rigid rods, such as increasing loading on interbody constructs, decreasing stress transfer to adjacent vertebral elements while bone-graft healing takes place, and generally balancing strength with flexibility.
• a spinal rod assembly may be formed by attaching an extension portion onto a spinal rod that extends along a longitudinal axis.
• the extension portion may be assembled in situ to a spinal rod that has been previously secured to vertebral bodies in a patient.
• the extension portion may be assembled to a spinal rod prior to insertion into a patient.
• the extension portion may include a rod coupler that attaches to the spinal rod with a first coupling that includes a first degree of rotational freedom and a first degree of translational freedom in positioning the rod coupler relative to the spinal rod along the longitudinal axis.
• the rod coupler may include an open channel formed between first and second walls, the channel sized to accept the spinal rod in a lateral direction between the first and second walls. One or both of the walls may include a retainer extending into the channel.
• the rod coupler may be positioned as desired relative to the spinal rod and secured.
• the extension portion may further include an extender rod including an elongated rod body that may be secured to the rod coupler using a second coupling that includes at least a second degree of rotational freedom in positioning the extender rod relative to the rod coupler about an axis substantially perpendicular to the longitudinal axis.
• the second coupling includes a second degree of translational freedom in establishing an offset of the rod extension relative to the spinal rod.
• Figure 1 is a top view of a rod assembly including a rod extender secured to vertebral members according to one embodiment
• Figure 2 is a perspective view of a spinal rod extender according to one embodiment
• Figure 3 is a perspective view of a spinal rod extender coupler according to one embodiment
• Figure 4 is a side view of a spinal rod extender coupler according to one embodiment
• Figure 5 is a top view of a spinal rod extender coupler according to one embodiment
• Figure 6 is a top view of a spinal rod extender coupler according to one embodiment
• Figure 7 is a top view of an extender rod according to one embodiment
• Figure 8 is a perspective view of an extender rod according to one embodiment
• Figure 9 is a top view of a spinal rod extender according to one embodiment
• Figure 10 is a perspective view of an exploded spinal rod extender assembly according to one embodiment
• Figure 11 is a front view of a spinal rod extender coupling block according to one embodiment
• Figure 12 is a side view of a spinal rod extender coupling block according to one embodiment
• Figure 13 is an axial view of a spinal rod extender assembly according to one embodiment.
• Figure 14 is side section view of a spinal rod extender assembly according to one embodiment.
• the spinal rod extenders may be secured to a conventional rod prior to or after implantation into a patient.
• a conventional rod may be similar to those used in the CD Horizon® rod systems available from Medtronic, Spinal & Biologies Division in Memphis, TN, USA.
• the rod extenders may be implanted at the same time and in conjunction with a conventional rod.
• the rod extenders also are advantageously attachable to conventional rods that are already secured to vertebral bodies in a patient.
• the rod extenders may be implanted at some time after a conventional rod is implanted, such as in a revision procedure.
• a spinal rod extender may be implemented in a spinal rod assembly of the type indicated generally by the numeral 20 in Figures 1 and 2.
• Spinal rods assemblies 20 of the type shown may be attached to a spine at various locations, including posterior, lateral, and anterior locations.
• Spinal rod assemblies 20 may also be attached at various sections of the spine, including the base of the skull and to vertebrae in the cervical, thoracic, lumbar, and sacral regions.
• the spinal rod assemblies 20 may be secured to the spine using conventionally known attachment anchors Al, A2, A3 such as pedicle screws or other threaded anchors, and other conventionally known hardware, including for example hooks and plates.
• the spinal rod assemblies 20 may include various lengths, diameters, and configurations.
• Figure 1 shows a top view of the spinal rod assembly 20 while Figure 2 shows a perspective view the spinal rod assembly 20 in which a conventional spinal rod R is attached to extender components, including an extender coupler 22 and an extender rod 24.
• the spinal rod assembly is shown relative to representative vertebral bodies Vl, V2, V3, illustrated simply as dashed blocks.
• the conventional spinal rod R may have been previously implanted into a patient and secured to vertebral bodies Vl, V2 using appropriate anchors Al, A2.
• anchors including for example fixed, and multi-axial pedicle screws also available with the CD Horizon® rod system family of devices.
• the extender coupler 22 and an extender rod 24 may be added to the existing rod R without having to remove the rod R or detach the anchors Al, A2.
• the rod coupler 22 and extender rod 24 are attached to the rod R in situ and the extender rod 24 may be secured to a third vertebral body V3 using a third anchor A3.
• the entire rod assembly 20 may be assembled and secured to the vertebral bodies Vl, V2, V3 at substantially the same time.
• the extender coupler 22 and extender rod 24 are generally constructed of biocompatible materials. These include metals such as stainless steels, cobalt-chrome, titanium, and shape memory alloys such as nitinol. Non-metallic components, including polymers made from materials such as PEEK and UHMWPE, are also contemplated. Those skilled in the art will comprehend various advantage and characteristics provided by different material choices. Through appropriate material choices, substantially rigid constructs or semi-rigid or flexible constructs may be created.
• a conventional spinal rod R generally includes an elongated body with a circular cross section. However, in the embodiments disclosed herein, non-circular cross sections are equally applicable. Cross section widths between about 3mm and about 8mm are known, though other sizes may be used.
• the extender coupler 22 includes a receiver section 26 that is configured to accept a rod R.
• One embodiment of an extender coupler 22 is shown in greater detail in the perspective view provided in Figure 3.
• Figure 4 shows a side view of this same extender coupler 22.
• Figure 5 shows a top view of this same extender coupler 22.
• the receiver section 26 includes a channel 28 that is sized to accept a rod R.
• the channel 28 is formed between an upper wall 30 and a lower wall 32 and a seating surface 34 extending therebetween.
• the upper wall 30 is longer than the lower wall 32.
• the upper and lower walls 30, 32 include substantially similar lengths.
• the lower wall 32 may be longer than the upper wall 30.
• the lower wall 32 may include a retention feature 36 to retain a rod R that is inserted into the channel 28.
• the retention feature 36 is formed as a protrusion that extends slightly into the channel 28 towards the upper wall 30. Once a rod R is secured in the channel 28, the retention feature 36 prevents the rod R from dislocating laterally out of the channel 28.
• the channel 28 is open laterally, with a coupler post 38 extending laterally in a direction opposite the open end of the channel 28.
• the channel 28 may be open towards the top or bottom of the extender coupler 22. There is no express requirement that the channel 28 and coupler post 38 extend laterally in opposite directions.
• a rod R may be secured within the channel 28 with a retainer 40 as shown in Figures 1 and 2.
• the retainer 40 may be implemented as a setscrew as shown, though other types of fasteners may be used.
• Exemplary retainers 40 may include pins, plugs, dowels, quarter-turn fasteners, clips, rings, and other fasteners conceivable by those skilled in the art.
• a setscrew retainer 40 as shown may provide substantial clamping forces to secure a rod R within the channel 28.
• the setscrew retainer 40 is insertable into a threaded aperture 42 in the upper wall 30 of the receiver section 26.
• the receiver section 26 includes a single threaded aperture 42 to receive a setscrew retainer 40.
• the receiver section 26 includes multiple threaded apertures 42 to receive multiple setscrew retainers 40 for additional securing to a rod R.
• the extender coupler 22 can be inserted onto and secured to the rod R by clamping the rod R within the channel 28 using the retainer 40.
• Figure 2 shows that there is some flexibility in attaching the extender coupler 22 to the rod R. Specifically, Figure 2 shows two sets of arrows labeled C and P, respectively. These arrows are shown relative to an X-Y-Z coordinate system.
• the rod R is generally aligned with the X-axis. It is generally known that rods R may be bent to conform to a patient anatomy or to achieve a desired spinal alignment.
• the rod R shown in Figures 1 and 2 is depicted as extending in a straight line.
• the X-Y-Z coordinate system remains relevant by aligning the X-axis of the coordinate system with the longitudinal axis of the rod R at the point where the extender coupler 22 is attached to the rod R.
• the extender coupler 22 may be positioned at various locations along the longitudinal length of the rod R. This flexibility is identified by the arrows labeled P, which extend along the X- axis or along the rod R axis.
• the extender coupler 22 may be positioned at various rotatable orientations identified by the arrows labeled C, which rotate about the X- axis or about the rod R axis. That is, the extender coupler 22 may be rotated and secured at various locations (limited potentially by anatomy) within the Y-Z plane. These arrows represent a single degree of translational freedom and a single degree of rotational freedom in positioning the extender coupler 22 to a rod R.
• the coupler post 38 extends from the receiver section 26.
• the coupler post 38 includes splines 44 extending longitudinally about the exterior surface of the coupler post 38.
• the extender rod 24 is attachable to the coupler post 38 in the manner illustrated in Figures 1 and 2.
• Figures 7 and 8 respectively illustrate top and side views of an extender rod 24 according to one embodiment.
• the extender rod 24 includes an elongated rod portion 46 that is formed substantially similar to conventional rods R. That is, the rod portion 46 includes a circular cross section with a diameter between about 3mm and about 8mm.
• different diameters and different materials will have different flexural and torsional rigidities. Those skilled in the art will comprehend suitable diameters to achieve desired rod strengths.
• the rod portion 46 may include non-circular and even asymmetric cross sections.
• the extender rod 24 includes an attachment portion 48 that is disposed at one end of the extender rod 24 in the embodiment shown. In the embodiment shown, the attachment portion 48 is enlarged compared to the rod portion 46. However, depending on the size of the rod portion 46 and the coupler post 38, the attachment portion 48 may include a similar size and width as the rod portion 46.
• the attachment portion 48 includes an aperture 50 that engages the coupler post 38 of the extender coupler 22. That is, the aperture 50 is sized to receive the coupler post 38. The aperture 50 may extend through the attachment portion 48 or may extend a predetermined depth.
• the aperture 50 may include one or more protrusions 52, including for example a plurality of splines, that engage correspondingly-configured splines 44 on the coupler post 38.
• the aperture 50 may include a slightly larger width than that of the coupler post 38. In this manner, the coupler post 38 may be rotated (as shown by the arrows labeled E in Figure 2) within the aperture 50 to achieve a desired orientation. Further, the extender rod 24 may be secured at varying offset distances from the rod R as indicated by the arrow S. The amount of adjustment in this offset direction S is limited by the length of the coupler post 38.
• the extender rod system 20 permits two-degrees of rotational freedom and two-degrees of translational freedom in assembling the rod extender components 22, 24 to the rod R.
• the coupler post 38 may be secured within the aperture 50 with a retainer 40 as shown in Figures 1 and 2.
• the retainer 40 may be implemented as a setscrew as shown, though other types of fasteners may be used.
• Exemplary retainers 40 may include pins, plugs, dowels, quarter-turn fasteners, clips, rings, and other fasteners conceivable by those skilled in the art.
• a setscrew retainer 40 as shown may provide substantial clamping forces to secure the coupler post 38 within the aperture 50.
• the splines 44, 52 cooperate to prevent rotation of the extender rod 24 relative to the extender coupler 22 after the retainer 40 is inserted.
• the setscrew retainer 40 is insertable into a threaded aperture 54 in the attachment portion 48.
• the attachment portion 48 includes a single threaded aperture 54 to receive a setscrew retainer 40.
• the attachment portion 48 includes multiple threaded apertures 54 to receive multiple setscrew retainers 40.
• Figures 1 and 2 depicted a rod assembly 20, including a single extender coupler 22 and a single extender rod 24 coupled to a conventional rod R.
• a rod system 100 shown in Figure 9 may be formed using multiple extender couplers 22 and extender rods 24.
• the rod system 100 includes a conventional rod R and a linked rod extender including two extender couplers 22 and two extender rods 24. Additional extender couplers 22 and extender rods 24 may be added as desired to achieve a desired overall length.
• Figure 10 depicts an embodiment of a rod extender system 110 that uses an extender coupler 22 for attachment to a conventional rod R as described above.
• an extender rod 24A is attached to the extender coupler 22 via a coupling block 56.
• the coupling block 56 couples the extender rod 24 A to the extender coupler 22.
• the coupling block 56 is rotatable in the direction of arrows F thereby providing flexibility in angling the extender rod 24A relative to the conventional rod R to which the extender coupler 22 is attached.
• Specific features of the exemplary coupling block 56 are more clearly visible in the front and side views provided in Figures 11 and 12.
• the illustrated coupling block 56 is generally rectangular in form, but other shapes are certainly permissible.
• the coupling block 56 includes an aperture 58 that engages the coupler post 38 of the extender coupler 22. That is, the aperture 58 is sized to receive the coupler post 38.
• the aperture 58 may extend through the coupling block 56 or may extend a predetermined depth.
• the aperture 58 may include one or more protrusions 52, including for example a plurality of splines, that engage correspondingly-configured splines 44 on the coupler post 38.
• the aperture 58 may include a slightly larger width than that of the coupler post 38.
• the coupler post 38 may be rotated (as shown by the arrows labeled F) within the aperture 58 to achieve a desired orientation. Then, the coupler post 38 may be secured within the aperture 58 with a retainer 4OA such as a setscrew or other member as described herein.
• a retainer 4OA such as a setscrew or other member as described herein.
• the coupling block 56 further includes an aperture 60 that engages the extender rod 24A. That is, the aperture 60 is sized to receive an end of the extender rod 24A. In the embodiment shown, the aperture 60 is oriented to face a direction that is substantially perpendicular to the extender post aperture 58. In other embodiments, the extender rod aperture 60 may face a direction other than substantially perpendicular to the extender post aperture 58.
• the aperture 60 may extend through the coupling block 56 or may extend a predetermined depth.
• the aperture 60 may include threads 62 that engage correspondingly-configured threads 64 on the extender rod 24A. Accordingly, the extender rod 24A may be threaded into the aperture 60 in the coupling block 56.
• the extender rod 24A may be secured using a retainer 4OA such as a setscrew or other member as described herein.
• a conventional rod R may be coupled to the coupling block 56 instead of the illustrated extender rod 24 A.
• the rod R may be inserted into the aperture 60 (which may or may not include threads 62 in the coupling block 56.
• the rod R may be secured using a retainer 4OA such as a setscrew or other member as described herein.
• Figures 13 and 14 illustrate an embodiment of a rod extender system 120 in which an extender coupler 22B engages an extender rod 24B.
• the extender coupler 22B includes a receiver section 26 that is configured to accept a rod R as described above.
• the extender coupler 22B includes an aperture 66 that extends between an enlarged insertion end 68 and a narrowed bottom end 70. Between these ends 68, 70, the aperture 66 includes a spherical surface 72 that is formed to substantially match and engage a spherical surface 74 of an enlarged end 76 of the extender rod 24B.
• the spherical surface 74 at the enlarged end 76 of the extender rod 24B and the spherical surface 72 of the aperture 66 form a ball and socket joint that permits poly-axial movement of the extender rod 24B relative to the rod R.
• the enlarged end 76 of the extender rod 24B may include ridges 78 that can be engaged by a tip 78 of a setscrew retainer 4OB.
• the tip 78 of the setscrew retainer 4OB may be pointed as shown. In other embodiments, the tip 78 may be spherical, cupped, conical, or other shapes that would occur to one skilled in the art.
• the tip 78 may be deformable and include relatively soft materials, including for example metal alloys including silver or polymers including nylon that are deformable to further engage and secure the enlarged end 76 of the extender rod 24B within the aperture 66 in the extender coupler 22B.
• the extender rod 24B is able to rotate or pivot about a plurality of axes as represented by the arrows labeled J, K, L in Figure 13. Notably, these axes are substantially perpendicular to the longitudinal axis of the rod R at the point where the extender coupler 22B is coupled to the rod R.

Landscapes

• Health & Medical Sciences (AREA)
• Orthopedic Medicine & Surgery (AREA)
• Neurology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Biomedical Technology (AREA)
• Surgery (AREA)
• General Health & Medical Sciences (AREA)
• Veterinary Medicine (AREA)
• Heart & Thoracic Surgery (AREA)
• Public Health (AREA)
• Animal Behavior & Ethology (AREA)
• Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
• Medical Informatics (AREA)
• Molecular Biology (AREA)
• Vascular Medicine (AREA)
• Transplantation (AREA)
• Oral & Maxillofacial Surgery (AREA)
• Cardiology (AREA)
• Surgical Instruments (AREA)
• Prostheses (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=38858994

Family Applications (1)

Country Status (7)

Cited By (9)

Families Citing this family (3)

Citations (8)

• 2007
  • 2007-08-29 BR BRPI0716086-0A2A patent/BRPI0716086A2/pt not_active IP Right Cessation
  • 2007-08-29 KR KR1020097005496A patent/KR20090043569A/ko not_active Application Discontinuation
  • 2007-08-29 EP EP07814527A patent/EP2063795A1/en not_active Withdrawn
  • 2007-08-29 WO PCT/US2007/077060 patent/WO2008027940A1/en active Application Filing
  • 2007-08-29 RU RU2009107996/14A patent/RU2009107996A/ru not_active Application Discontinuation
  • 2007-08-29 AU AU2007289258A patent/AU2007289258A1/en not_active Abandoned
  • 2007-08-29 CN CNA2007800321617A patent/CN101511289A/zh active Pending

Patent Citations (8)

Also Published As

Similar Documents

Legal Events