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EP-4523641-B1 - BONE ANCHOR HEAD EXTENDER

EP4523641B1EP 4523641 B1EP4523641 B1EP 4523641B1EP-4523641-B1

Inventors

  • LENGYEL, Rebecca Boerigter
  • HARPER, RYAN
  • LUBENSKY, SCOTT
  • DANIELS, DAVID WAYNE
  • Gibbs, Collin
  • LUHMANN, SCOTT J.

Dates

Publication Date
20260513
Application Date
20191212

Claims (14)

  1. A bone anchor head extender (10) comprising: a mounting bar (60) sized to fit and be secured into a pedicle screw tulip head (106) of a fixed pedicle screw (100), the mounting bar (60) having a central axis (62) at a first elevation (D1); and an extender tulip head (64) disposed on an upturned end of the mounting bar (60), the extender tulip head (64) having two opposing arms (16/18), each one of the two opposing arms (16/18) including a portion of interior threads (20) and extending from a curved lower surface defining a substantially U-shaped interior channel (22) having a first channel axis (24) disposed at a second elevation (D2) above the first elevation (D1), characterized in that the extender (10) comprises unitary construction.
  2. The extender (10) according to claim 1, wherein the extender facilitates positioning of a spinal fixation rod (122) both laterally and upwardly with respect to the pedicle screw tulip head (106).
  3. The extender (10) according to any of the preceding claims, wherein the extender (10) is configured to facilitate laterally in-line positioning of rod (122).
  4. The extender (10) according to claims 1 or 2, wherein the extender (10) is configured to facilitate laterally elevated cross positioning of rod (122).
  5. The extender (10) according to any of the preceding claims, wherein the mounting bar (60) comprises a cylindrical shape and sized to fit and be secured into the tulip head (106) of the pedicle screw (100).
  6. The extender (10) according to claims 1, 2, or 4-5, wherein the extender tulip head (64) is oriented such that the first channel axis (24) is parallel to but in a different place than the central axis (62).
  7. The extender (10) according to claims 1, 2, or 4-6, wherein the extender tulip head (64) is oriented such that the first channel axis (24) is in a plane that is substantially perpendicular to a plane in which the central axis (62) resides.
  8. The extender (10) according to claims 1, 2, or 4-7, wherein the first interior threads (20) of the first and second arms (16/18) are complementary to receive an appropriately sized set screw.
  9. The extender (10) according to claims 1, 2, or 4-8, wherein the extender (10) facilitates fixation of a rod (122) first interior threads (20) of the first and second arms (16/18) are complementary to receive an appropriately sized set screw.
  10. The extender (10) according to any of the preceding claims, wherein the extender tulip head (64) include features to engage a rod reducing tool.
  11. The extender (10) according to claims 1, 2, or 3, wherein the extender tulip head (64) is configured such that the first channel axis (24) is positioned in-line with the central axis (62).
  12. The extender (10) according to any of the preceding claims, further characterized by a set screw configured to engage internal threads (116) of the tulip head (106) to secure the mounting bar (60) in the tulip head 106.
  13. The extender (10) according to claim 1, wherein the first channel axis (24) and the central rod axis (62) of the mounting bar (60) are parallel and in the same plane such that when a fixation rod (122) is reduced into the extender tulip head (64), the fixation rod (122) is in-line with the mounting bar (60) first interior threads are configured to receive a set screw.
  14. The extender (10) according to claim 1, wherein the extender tulip head (64) is oriented such that when a rod (122) is reduced into the extender tulip head (64), the rod (122) is not in-line with the mounting bar (60) and elevated by a distance (D2) from the mounting bar.

Description

This application claims the priority benefit of U.S. Provisional Patent App. No. 62/778,663 filed December 12, 2018. Background Spinal fixation systems may be used to surgically fix, adjust, and/or align the spinal column. One type of spinal fixation system employs a spinal rod for supporting the spine and fixing, adjusting, and/or aligning all or portions of the spinal column into a desired orientation. Attachment of the spinal rod to the spinal column has been achieved using a variety of vertebral anchors. Pedicle screws have been used successfully as vertebral anchors. Pedicle screws and connectors in combination with spinal rods can align and correct deformities in the natural spinal alignment as well as repair traumatic injury. In general, a pedicle screw has a head with a receiving opening into which a spinal rod can be secured. However, once a pedicle screw is set, i.e., screwed into a portion of the pedicle bone, the location of a spinal rod to be set into it is also set due to the fixed position of the head of the pedicle screw. It can be the case that during the process of spinal fixation it is discovered that the fixed location of the head of the pedicle screw, and, therefore, the fixed location of the reduced spinal rod, is not ideal. In this regard, US 2012/0179205 A1 discloses a spinal stabilization apparatus and method according to which a fastener is engaged with a bone structure of a spinal system. The fastener is connected to a rod by moving the rod downward toward the fastener in a sagittal plane, and the direction of extension of at least a portion of the rod in a coronal plane may be selectively adjusted in predetermined angular increments through 360 degrees. Starting from prior art, however, there remains an unmet need for an apparatus, system, and method to provide for variable positioning of a spinal rod in a fixed pedicle screw. Further, there remains an unmet need for spinal fixation apparatus that permits greater flexibility for neuromuscular and revision cases by providing for a greater variety of instrumentation. Summary According to the present invention, a bone anchor, such as a pedicle screw, head extender is disclosed. The extender can include a mounting bar sized to fit and be secured into a pedicle screw tulip head of a fixed pedicle screw, the mounting bar having a central axis at a first elevation. An extender tulip head is disposed on an upturned end of the mounting bar, the extender tulip head having two opposing arms, each one of the two opposing arms including a portion of interior threads and extending from a curved lower surface defining a substantially U-shaped interior channel having a first channel axis disposed at a second elevation above the first elevation. The extender comprises unitary construction. Preferred embodiments are set forth in the dependent claims. Associated surgical methods are also described herein to aid understanding the invention. These methods do not form part of the claimed invention. Brief Description of the Drawings The present disclosure will be more readily understood from a detailed description of some example embodiments taken in conjunction with the following figures. The embodiments which form part of the invention are illustrated in the figures 22-25. The examples shown in the other figures do not form part of the invention but represent background art that is useful for understanding the invention. FIG. 1 depicts a side elevation view of an example of a pedicle screw.FIG. 2 depicts a partial cross-sectional view of a head of the pedicle screw of FIG. 1.FIG. 3 depicts a schematic representation of a pedicle screw in a bone.FIG. 4 depicts a perspective view of one example of a pedicle screw extender of the present disclosure engaged with a pedicle screw.FIG. 5 depicts a perspective view of the pedicle screw extender of FIG. 4.FIG. 6 depicts a perspective view of one example of a pedicle screw extender of the present disclosure.FIG. 7 depicts a perspective view of the pedicle screw extender of FIG. 6.FIG. 8 depicts a top perspective view of the pedicle screw extender of FIG. 6.FIG. 9 depicts a side elevation view of the pedicle screw extender of FIG. 6.FIG. 10 depicts a side elevation view of the pedicle screw extender of FIG. 6.FIG. 11 depicts a partial cross-sectional view of Section 11-11 of FIG. 9.FIG. 12 depicts a partial cross-sectional view of Section 12-12 of FIG. 10.FIG. 13 depicts a perspective view of one example of a pedicle screw extender of the present disclosure.FIG. 14 depicts a perspective view of one example of a pedicle screw extender of the present disclosure engaged to head of a pedicle screw.FIG. 15 depicts a perspective view of a portion of the pedicle screw extender of FIG. 14.FIG. 16 depicts a perspective view of the pedicle screw extender of FIG. 14 partially engaged with a head of a pedicle screw.FIG. 17 depicts a perspective view of a portion of the pedicle screw extender of FIG. 14 engaged with a head