Bone anchor head extender

Inventors

LENGYEL, REBECCA BOERIGTER • Harper, Ryan • Lubensky, Scott • Daniels, David Wayne • Gibbs, Collin • Luhmann, Scott J.

Assignees

Orthopediatrics Corp

Abstract

A pedicle screw tulip head extender. The extender can include an upper body portion joined to a lower body portion. The upper body portion can have two opposing arms extending upwardly from a curved lower surface to define a substantially U-shaped interior channel having a first channel axis, the curved lower surface defining an access opening extending through the upper body portion in a direction generally perpendicular to the first channel axis. The lower body portion can extend downwardly as a protrusion from the upper body portion and can be joined to the upper body portion and can have first and second sides, the first and second sides being substantially planar and parallel and separated by an interior portion, the first and second sides defining a protrusion height and a protrusion width. A screw can be disposed in the interior portion and have external threads defining a thread diameter greater than the protrusion width.

Core Innovation

The described invention relates to a pedicle screw tulip head extender that is attachable in a spinal fixation system and is configured to be disposed within a tulip head channel defined between first and second arms of a pedicle screw tulip head. The extender includes an upper body portion having two opposing arms extending upwardly from a curved lower surface to define a substantially U-shaped interior channel with a first channel axis, and an access opening extending through the upper body portion generally perpendicular to the first channel axis.

The lower body portion extends downwardly as a protrusion joined to the upper body portion, with first and second sides that are substantially planar and parallel and separated by an interior portion, the sides defining a protrusion height and a protrusion width. A screw is disposed in the interior portion with external threads defining a thread diameter greater than the protrusion width.

When the lower body portion is disposed within the tulip head channel, the extender provides a second tulip head arrangement for receiving and seating a spinal fixation rod while avoiding disturbing the installed pedicle screw head. The access opening enables driving an internal extender set screw to interact with tulip internal threads, and the substantially U-shaped interior channel defines a channel in which a rod can be positioned.

Multiple embodiments are described for spinal fixation systems, including discrete saddle/cap/set-screw configuration and extenders having different channel axis orientations. The channel axis orientations enable in-line or angled rod positioning relative to a mounting bar, and the document states intended orthopedic spinal regions including lumbar, thoracic, and cervical regions and use cases including revision/neuromuscular cases and curved-spine scenarios.

Claims Coverage

The provided independent claims are clm-00001 and clm-00012. The inventive features focus on a pedicle screw tulip head extender whose lower protrusion and threaded screw geometry is configured to be disposed within a tulip head channel, and on a spinal fixation arrangement in which a generally straight/angled mounting rod portion is disposed within the tulip head channel of a pedicle screw.

Across the independent claims, the claim coverage centers on a pedicle screw tulip head channel and a tulip head extender/rod securing structure that defines a substantially U-shaped interior channel with an access opening for an internal set screw, and whose lower threaded protrusion geometry is configured for disposition within the tulip head channel; in the second independent claim this is combined with a mounting rod that is straight at one end and turned at an angle, with the mounting rod portion disposed within the tulip head channel at an elevated channel-axis configuration.

Stated Advantages

Documented Applications