Plate distractor and assembly of such a plate distractor and an activation tool

Patent metadata

Field	Value
Publication number	US-10736664-B2
Application number	US-201616060689-A
Country	US
Kind code	B2
Filing date	Dec 9, 2016
Priority date	Dec 9, 2015
Publication date	Aug 11, 2020
Grant date	Aug 11, 2020

Abstract

The invention relates to a plate distractor, particularly a maxillofacial plate distractor, comprising a first (12) and a second (14) fixing plate, a threaded pin (24) mounted in a freely rotatable and translatably fixed manner in relation to the first fixing plate (14), a screwed tube (26) fixed to the second fixing plate (12), a permanent magnet (20) extending in a main direction, which is magnetised transversely to the main direction and mounted in the plate distractor (10) such that the rotation of the magnet (20) on itself, about an axis of rotation (D) parallel to the main axis, causes a relative rotation of the threaded pin (24) in relation to the screwed tube (26), the magnet (20) being arranged close to one of the ends of the plate distractor (10).

First claim

The invention claimed is:

1. A distractor assembly comprising:
a plate distractor comprising:
a first and a second fixing plate,
a threaded rod
a threaded tube mounted on the threaded rod and attached to the second fixing plate,
a sleeve accommodating the threaded rod that is freely rotatable and translatably fixed relative to the sleeve and the threaded tube that is freely translatable and rotatably fixed relative to the sleeve,
a permanent magnet accommodated in a housing, extending in a main direction and magnetized transverse to the main direction, mounted in the plate distractor such that the rotation of the magnet on itself around an axis of rotation parallel to the main axis causes a relative rotation of the threaded rod in relation to the threaded tube, with the magnet being located at a distance from one of the ends of the plate distractor, measured in the direction of the axis of rotation of the magnet, of less than or equal to 15 mm,

an activation tool of the plate distractor comprising a permanent magnet extending in a main direction and magnetized transverse to the main direction, configured to be placed opposite the magnet of the plate distractor such that their magnetization directions are essentially parallel and causing the magnet of the plate distractor to rotate by rotating the magnet of the activation tool around an axis that is essentially colinear with the axis of the permanent magnet of the distractor.

2. The assembly according to claim 1 , wherein the magnet of the distractor is located at one end of the plate distractor.

3. The assembly according to claim 1 , wherein the magnet of the plate distractor is cylindrical.

4. The assembly according to of claim 1 , the plate distractor comprising an angle gear device such that the axis of rotation of the magnet is essentially perpendicular to the axis of the threaded rod and of the threaded tube.

5. The assembly according to claim 4 , wherein the angle gear device comprises a first gear rotationally fixed to the magnet and adapted to engage with a second gear controlling the rotation of one of the threaded rod and the threaded tube.

6. The assembly according to claim 1 , wherein the magnet is connected to the threaded rod or the threaded tube by a reduction device.

7. The assembly according to claim 4 , wherein the angle gear device comprises a first gear rotationally fixed to the magnet and adapted to engage with a second gear controlling the rotation of one of the threaded rod and the threaded tube and the reduction device includes the first and second gears.

8. The assembly according to claim 1 , the plate distractor comprising an arm connected to the threaded tube by a ball and pin connection, wherein the ball and pin connection is implemented by means of a universal joint, the universal joint being provided between the arm and the treaded rod.

9. The assembly according to claim 1 , wherein the magnet of the plate distractor is rotationally fixed to the threaded rod or the threaded tube.

10. The assembly according to claim 1 , the plate distractor comprising a non-return device that prevents the rotation of the magnet of the plate distractor in one direction, controlling a reduction in the distance between the first and second plates.

11. The assembly according to claim 1 , wherein the magnet of the plate director is composed of neodymium or neodymium alloy, samarium or samarium alloy, ferrite or ferrite alloy.

12. The assembly according to claim 1 , wherein at least one of the threaded tube, the first plate and the second plate is/are composed of titanium or titanium alloy.

13. The assembly according to claim 1 , wherein the housing is attached to the threaded rod.

14. The assembly according to claim 1 , wherein the threaded tube has a width less than or equal to the width of the second plate.

15. The assembly according to claim 1 , wherein the permanent magnet of the plate distractor is such that its magnetization is retained when it is heated to a temperature of 120° C.

16. The assembly according to claim 1 , wherein the threaded rod is mounted in a freely rotatable and translatably fixed manner in relation to the first fixing plate.

17. The assembly according to claim 1 , wherein the threaded rod comprises two longitudinal areas having opposite threads, with the first threaded tube to which the second plate is attached being mounted on one of the two longitudinal areas and a second threaded tube to which the first plate is attached being mounted on the other of the two longitudinal areas.

18. The assembly according to claim 1 , wherein the magnet and the housing are configured such that the magnet is freely rotatable in the housing when it rotates in a first direction and the magnet rotationally drives the housing and thus the threaded rod when it rotates in a second direction.

19. The assembly according to claim 1 , the plate distractor comprising a device for determining the extension length of the distractor.

20. The assembly according to claim 1 , the housing being hermetically sealed.

21. The assembly according to claim 1 , wherein the activation tool comprises a magnetic shielding housing wherein the magnet is accommodated, with the magnetic shielding housing being capable of moving from a closed configuration in which the shielding of the magnetic field is sufficient to prevent the rotation of the magnet of the activation tool around the main direction from causing rotation of the magnet of the plate distractor around its axis to an open configuration in which the rotation of the magnet of the activation tool around the main direction causes the rotation of the magnet of the plate distractor around its axis and vice versa.

22. The distraction assembly according to claim 1 , wherein the magnet of the activation tool is cylindrical.

23. The assembly according to claim 1 , the magnet being located at a distance from one of the ends of the plate distractor, measured in the direction of the axis of rotation of the magnet, of less than or equal to 10 mm.

24. The assembly according to claim 18 , the magnet comprising an asymmetrical notch and the housing comprising a projection cooperating with the notch such that the magnet is free to rotate in the first direction and the projection engages with the notch in the second direction.

Assignees

• Ecole Nat Supérieure De Techniques Avancées
• Ecole Polytech
• Université Paris Descartes
• Assist Publique—Hôpitaux De Paris
• Ecole Nat Superieure De Techniques Avancees

Inventors

• Strozyk Hervé
• Boisson Jean
• Cherfa Lahcen
• Kadlub Natacha
• Picard Arnaud

Classifications

• A61B17/66

  {Alignment}, compression or distraction mechanisms · CPC title

• A61B2017/681

  Alignment, compression, or distraction mechanisms · CPC title

• A61B17/663 Primary

  for jaw bones, e.g. subcutaneous distractors with external access (periodontal bone regeneration A61C8/0006) · CPC title

• A61B17/808

  Instruments for holding or positioning bone plates, or for adjusting screw-to-plate locking mechanisms · CPC title