Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Publication Number
US-12201337-B2
Publication Date
2025-01-21
Expiration Date
Abstract
An expandable laminoplasty device has a superior plate, an inferior plate, threaded or racked gear post having external threads or gear teeth, the post affixed to one of the superior plate or the inferior plate, and a gear nut or pinion gear, the gear has internal threads or external gear teeth configured to engage external threads or gear teeth of the post. The gear is held in one of the superior plate or inferior plate not affixed to the post and wherein the superior plate or inferior plate not affixed to the post has an end with a slot or channel to receive the post and a side opening to receive and hold the gear.
Core Innovation
The invention is an expandable laminoplasty device for a cervical vertebra that includes a superior plate and an inferior plate coupled by a gear-based mechanism configured for continuous adjustment between a contracted position and an expanded position. A racked gear post having gear teeth is affixed to one of the superior plate or the inferior plate, while a pinion gear having gear teeth is held in the other plate not affixed to the racked gear post, and rotation of the pinion gear engages the gear teeth of the racked gear post to couple the plates.
Rotation of the pinion gear causes relative movement of the superior plate and inferior plate from contracted to expanded positions, and stopping the rotation fixes an amount of linear expansion between the superior and inferior plates. The disclosed plate interfaces include an end of the non-racked-gear-affixed plate having a slot or channel to receive the racked gear post and a side opening to receive and hold the pinion gear, with structural arrangements that captively hold the gear and allow linear movement while constraining rotation.
The device further includes a second post spaced from the racked gear post, with the racked gear post having the gear teeth facing inwardly and the pinion gear positioned in a central location on one of either the superior plate or inferior plate. The superior plate and inferior plate include a hooked end with ridges for engaging cut lamina and a bone-contacting inferior end with ridges, along with fastener holes, and the summary emphasizes continuous adjustment rather than ratcheted or discrete-length plates.
The problem addressed is providing an expandable cervical laminoplasty device that can enlarge the spinal canal opening by moving a superior plate and an inferior plate between contracted and expanded positions with an adjustable linear expansion amount. By coupling the plates through engagement of a racked gear post and a pinion gear and fixing the linear expansion by stopping pinion rotation, the device is configured to complete the laminoplasty with controlled plate separation.
Claims Coverage
The partial content includes two independent claims, a device claim and a method claim. Across these independent claims, the coverage centers on a racked gear post and pinion gear coupling a superior plate and inferior plate to provide relative movement between contracted and expanded positions, with stopping pinion rotation fixing linear expansion, and a constrained plate-gear mounting arrangement including a slot or channel and a second post.
Expandable laminoplasty device with racked gear post and pinion-driven plate coupling
An expandable laminoplasty device comprising a superior plate; an inferior plate; a racked gear post having a plurality of gear teeth affixed to one of the superior plate or the inferior plate; and a pinion gear having a plurality of gear teeth configured to engage the gear teeth of the racked gear post, wherein the pinion gear is held in one of the superior plate or inferior plate not affixed to the racked gear post, with an end having a slot or channel to receive the racked gear post and a side opening to receive and hold the pinion gear.
Pinion rotation fixes linear expansion between plates in contracted and expanded positions
Rotation of the pinion gear engages the gear teeth of the racked gear post to couple the superior plate to the inferior plate, where rotation of the pinion gear causes relative movement of the superior plate and inferior plate from contracted to expanded positions, and stopping the rotation of the pinion gear fixes an amount of linear expansion between the superior and inferior plates.
Second post spacing with central pinion positioning and inward-facing racked gear teeth
The assembly includes a second post spaced from the racked gear post, wherein the racked gear post has the gear teeth facing inwardly and the pinion gear is positioned in a central location on one of either the superior plate or inferior plate to expand or contract the assembly.
Method of cervical laminoplasty using pinion-rotated expandable laminoplasty device
A method of performing a laminoplasty comprises preparing a cervical vertebra by cutting through a lamina and partially cutting through the lamina at a spaced second location; providing an expandable laminoplasty device having a superior plate, an inferior plate, a racked gear post affixed to one of the superior plate or the inferior plate, and a pinion gear held in the other plate with the slot or channel and side opening arrangement; positioning the expandable laminoplasty device in a contracted position with a hooked end of the superior plate on the cut lamina and the inferior plate on the lateral mass of the vertebra; fastening ends of both superior and inferior plates to the cut lamina and the lateral mass respectively using fasteners; and rotating the pinion gear to expand the expandable laminoplasty device to a location enlarging a spinal canal opening of the vertebra completing the laminoplasty.
Across the independent claims, the main inventive concept is coupling a superior plate and an inferior plate using a racked gear post and a pinion gear where pinion rotation drives the plates between contracted and expanded positions, and stopping pinion rotation fixes linear expansion, with mounting constrained by an end slot or channel receiving the racked gear post and a second post spaced from the racked gear post supporting the assembly geometry.
Stated Advantages
Provides continuous adjustment between contracted and expanded positions, rather than ratcheted or discrete-length plates.
Stopping rotation fixes an amount of linear expansion between the superior and inferior plates.
Expands the device to a location enlarging a spinal canal opening of the vertebra completing the laminoplasty.
Documented Applications
Expandable cervical laminoplasty device used to enlarge a spinal canal opening by expanding from a contracted position to an expanded position during cervical laminoplasty.
Method of performing a laminoplasty on a cervical vertebra, including positioning the device on the cut lamina and lateral mass and rotating the pinion gear to complete the laminoplasty.
Interested in licensing this patent?