Flat plate mechanisms for bone lengthening

Patent metadata

Field	Value
Publication number	US-12558133-B2
Application number	US-202318306990-A
Country	US
Kind code	B2
Filing date	Apr 25, 2023
Priority date	Apr 25, 2023
Publication date	Feb 24, 2026
Grant date	Feb 24, 2026

Abstract

Provided herein is an adjustable implant configured to non-invasively guide bone growth in a patient. The adjustable implant includes a first portion configured to couple to a first bone segment and a second portion at least partially disposed within the first portion and configured to couple to a second bone segment. The adjustable implant includes a drive assembly configured to be transcutaneously actuated, and to drive rotation of a gear assembly configured to rotate about a first axis, and drive axial translation of the second portion along a second axis. Non-invasive actuation of the drive assembly therefore causes the adjustable implant to distract or retract along the second axis.

First claim

What is claimed is:

1 . An adjustable implant comprising:
a first portion configured to couple to a first bone segment; a drive assembly comprises a driver disposed within the first portion and configured to drive rotational motion about a first axis; a second portion configured to couple to a second bone segment and axially translate relative to the first portion along a second axis; and a lead screw disposed at least partially within the first and second portions along the second axis, wherein the lead screw is rotatably coupled to the drive assembly such that rotational motion about the first axis drives rotational motion of the lead screw about the second axis, thereby causing the second portion to axially translate along the second axis relative to the first portion, wherein the driver comprises a rotatable permanent magnet configured to be rotated by an externally applied magnetic field, wherein the first axis and the second axis intersect, and wherein the first axis and the second axis form an oblique angle.

2 . The adjustable implant of claim 1 , wherein the first axis is orthogonal to the second axis.

3 . The adjustable implant of claim 1 , wherein the drive assembly further comprises:
a drive shaft rotatably coupled to the driver, and wherein the driver is configured to rotate about the first axis in a first direction corresponding to proximal translation of the second portion and in a second direction corresponding to distal translation of the second portion.

4 . The adjustable implant of claim 3 , further comprising a gear assembly rotatably coupled to the drive shaft, wherein the gear assembly is configured to rotatably engage the lead screw to drive rotational motion of the lead screw about the second axis.

5 . The adjustable implant of claim 4 , wherein the gear assembly comprises a beveled output gear, and the lead screw comprises a beveled gear configured to matingly engage the beveled output gear.

6 . The adjustable implant of claim 5 , wherein the gear assembly further comprises:
a first ring gear rotationally fixed to the first portion of the distraction device; a first sun gear disposed within the first ring gear and rotatably coupled to the drive shaft; a second sun gear rotatably coupled to a distal end of the drive shaft; a plurality of compound planetary gears disposed about the first axis, wherein each compound planetary gear comprises a first gear configured to engage the first sun gear, and a second gear configured to engage the second sun gear; and a second ring gear configured to receive and rotatably engage the second gears of the plurality of compound planetary gears, wherein the beveled output gear is rotatably coupled to the second ring gear, such that rotation of the second ring gear about the first axis causes rotation of the beveled output gear about the first axis, and rotation of the beveled output gear about the first axis is configured to drive rotational motion of the lead screw about the second axis.

7 . The adjustable implant of claim 6 , wherein the first ring gear comprises a first cavity configured to receive the driver therein, a second cavity configured to receive the first gears of the plurality of compound planetary gears therein, and an aperture dimensioned to receive the drive shaft therein to enable communication between the first cavity and the second cavity.

8 . The adjustable implant of claim 1 , further comprising:
a third portion configured to couple to a third bone segment and axially translate along a third axis relative to the first portion; a second lead screw disposed at least partially within the first and third portions along the third axis, wherein the second lead screw is configured to rotatably engage the drive assembly to drive rotational motion of the second lead screw about the third axis, thereby causing the third portion to axially translate along the third axis relative to the first portion.

9 . The adjustable implant of claim 1 , further comprising:
a first fixation anchor configured to couple the first portion of the distraction device to the first bone segment; and a second fixation anchor configured to couple the second portion of the distraction device to the second bone segment, wherein each of the first portion and the second portion comprise a receiving aperture configured to receive the first fixation anchor and the second fixation therein, respectively.

10 . An adjustable implant comprising:
a first portion configured to couple to a first bone segment; a gear assembly disposed in the first portion; a drive assembly configured to rotatably engage the gear assembly and to rotate about a first axis, wherein the drive assembly is configured to drive rotational motion of the gear assembly about a second axis; a lead screw disposed at least partially within the first portion, and extending along a third axis; and a second portion configured to couple to a second bone segment, wherein the lead screw is at least partially disposed within the second portion, wherein the lead screw is rotatably coupled to the drive assembly such that rotational motion of the drive assembly about the first axis drives rotational motion of the gear assembly about the second axis, which drives rotational motion of the lead screw about the third axis, thereby causing the second portion to axially translate along the third axis relative to the first portion, and wherein the third axis is parallel to the first axis and orthogonal to the second axis.

11 . The adjustable implant of claim 10 , wherein the first axis and the second axis form a first angle, and wherein the first axis and the third axis form a second angle different than the first angle.

12 . An adjustable implant comprising:
a first portion configured to couple to a first bone segment; a drive assembly disposed within the first portion and configured to rotate about a first axis, wherein the drive assembly comprises a driver configured to rotate about the first axis, and a drive shaft rotatably coupled to the driver; a second portion configured to couple to a second bone segment and axially translate relative to the first portion along a second axis; and a ratchet assembly disposed at least partially within the first and second portions, wherein the ratchet assembly is configured to actuate axial translation relative to the first portion along the second axis in response to rotation of the drive assembly about the first axis, and to inhibit retraction of the second portion relative to the first portion along the second axis, and wherein the driver comprises a rotatable permanent magnet configured to be rotated by an externally applied magnetic field.

13 . The adjustable implant of claim 12 , wherein each of the first and second portions comprises a flat plate, and wherein the first axis is orthogonal to the second axis.

14 . The adjustable implant of claim 12 , further comprising:
a gear assembly disposed within the first portion and configured to rotate in response to the rotation of the drive assembly, wherein the gear assembly comprises: an input gear rotatably coupled to the drive shaft; an output gear rotatably coupled to the input gear; and an eccentric shaft rotatably coupled to the output gear, wherein the eccentric shaft is configured to engage the ratchet assembly to actuate axial translation of the second portion along the second axis relative to the first portion in response to rotation of the drive assembly.

15 . The adjustable implant of claim 14 , wherein the ratchet assembly comprises:
a ratchet arm hav

Assignees

• Nuvasive Specialized Orthopedics Inc
• Nuvasive Inc

Inventors

• Meyer Nathan
• Chen Emmon
• Buenviaje Gabriel
• Lawson Kaila
• Yang Sherrie

Classifications

• A61F2002/30706

  specially designed for children, e.g. having means for adjusting to their growth · CPC title

• A61B17/8023 Primary

  Variable length plates adjustable in both directions · CPC title

• A61B17/8004

  with means for distracting or compressing the bone or bones · CPC title

• A61B2017/681

  Alignment, compression, or distraction mechanisms · CPC title

• A61B2017/00407

  Ratchet means · CPC title