Growing rod for treating spinal deformities and method for using same

Patent metadata

Field	Value
Publication number	US-9949759-B2
Application number	US-201514874771-A
Country	US
Kind code	B2
Filing date	Oct 5, 2015
Priority date	Oct 5, 2015
Publication date	Apr 24, 2018
Grant date	Apr 24, 2018

Abstract

A growing rod adapted to be secured along a length of a spine for treating deformities of the spine. The growing rod comprises a base rod, an extendable rod having a proximal portion that is slidably coupled to the base rod and arranged with a gear rack, and a distraction unit. The distraction unit includes a housing attached to the base rod, a rotatable drive interface accessible by an external driver from outside of the housing, and a drive gear mechanism housed within the housing and coupled to the rotatable drive interface and the gear rack such that rotation of the rotatable drive interface causes linear movement of the extendable rod through the gear rack.

First claim

What is claimed is:

1. A growing rod adapted to be secured along a length of a spine for treating deformities of the spine, comprising:
a base rod;
an extendable rod having a proximal portion that is slidably coupled to the base rod and arranged with a gear rack; and
a distraction unit having:
(i) a housing attached to the base rod;
(ii) a rotatable drive interface accessible by an external driver from outside of the housing;
(iii) a drive gear mechanism housed within the housing and coupled to the rotatable drive interface and the gear rack such that rotation of the rotatable drive interface causes linear movement of the extendable rod through the gear rack, wherein the drive gear mechanism includes a drive gear and a pinion that are coupled to the rotatable drive interface such that rotation of the rotatable drive interface causes the drive gear and the pinion to rotate.

2. The growing rod of claim 1 , wherein:
the drive gear mechanism has a gear ratio lower limit of 1.5; and
the drive gear mechanism has a gear ratio upper limit of 10.

3. The growing rod of claim 1 , wherein the pinion is coupled to the gear rack such that rotation of the pinion causes the linear movement of the extendable rod through the gear rack.

4. The growing rod of claim 1 , wherein the drive gear mechanism includes an idler gear coupled to and positioned between the drive gear and the pinion, thereby forming a simple gear train.

5. The growing rod of claim 4 , wherein the drive gear and the idler gear are the same size and have the same number of teeth.

6. The growing rod of claim 1 , wherein:
the base rod has a first opening that is substantially the same size and shape as a second opening arranged on the housing; and
the first and second openings overlap each other to allow teeth of the pinion to mesh with teeth of the gear rack.

7. The growing rod of claim 1 , wherein the rotatable drive interface is adapted to be accessed by the external driver from outside of the housing and to be physically coupled to and manually rotated by the external driver for extending and retracting the extendable rod relative to the base rod.

8. The growing rod of claim 1 , wherein the distraction unit further includes:
a latching mechanism housed within the housing and adapted to latch onto a gear of the drive gear mechanism such that rotation of the rotatable drive interface is prohibited in a direction that retracts the extendable rod.

9. The growing rod of claim 8 , wherein the latching mechanism includes a latch that is biased to lock the drive gear mechanism.

10. The growing rod of claim 9 , wherein the latch is sized and shaped to be received between a pair of adjacent teeth of the gear to prohibit the rotatable drive interface from rotating in the direction that retracts the extendable rod.

11. The growing rod of claim 9 , wherein the distraction unit further includes:
a rotatable cam interface accessible by an external cam driver from outside of the housing; and
a cam housed within the housing and coupled to the rotatable cam interface such that rotation of the rotatable cam interface causes the latching mechanism to prohibit or allow the drive gear mechanism to rotate in the direction that retracts or extends the extendable rod.

12. The growing rod of claim 11 , wherein the rotatable cam interface is adapted to be physically coupled to and manually rotated by the external cam driver such that rotation of the rotatable cam interface causes a tip of the cam to engage or be free from physical contact with the latch.

13. The growing rod of claim 1 , wherein the housing further includes:
a guide wall that surrounds the rotatable drive interface; and
the guide wall has a pair of oppositely positioned recesses, each of which is adapted to receive a corresponding protrusion of the external driver to prevent lateral movement of the external driver.

14. A growing rod adapted to be secured along a length of a spine for treating deformities of the spine, comprising:
a base rod;
an extendable rod having a proximal portion that is slidably coupled to the base rod and arranged with a gear rack; and
a distraction unit having:
(i) a housing attached to the base rod;
(ii) a rotatable drive interface accessible by and adapted to physically couple to an external driver from outside of the housing;
(iii) a pinion housed within the housing and coupled to the gear rack to form a rack-and-pinion; and
(iv) a drive gear housed within the housing and coupled between the rotatable drive interface and the rack-and-pinion such that rotation of the rotatable drive interface by the physically coupled external driver causes the rack-and-pinion to linearly move the extendable rod relative to the base rod.

15. The growing rod of claim 14 , wherein the rotatable drive interface is adapted to be manually rotated by a user using the physically coupled external driver for extending and retracting the extendable rod relative to the base rod.

16. The growing rod of claim 14 , wherein the distraction unit further includes:
a rotatable cam interface accessible by and adapted to be physically coupled to an external cam driver from outside of the housing; and
a cam housed within the housing and coupled to the rotatable cam interface such that rotation of the rotatable cam interface by the physically coupled external cam driver causes a latching mechanism housed within the housing to prohibit or allow the drive gear and pinion to rotate in a direction that retracts or extends the extendable rod.

Assignees

• Globus Medical Inc

Inventors

• Lynch Bobby
• Juchno Brad
• Muzumdar Aditya
• Ingalhalikar Aditya
• Gordon Jeffrey David

Classifications

• A61B17/7017

  pneumatic or hydraulic means · CPC title

• A61B2017/681

  Alignment, compression, or distraction mechanisms · CPC title

• A61B17/7014 Primary

  with means for adjusting the distance between two screws or hooks · CPC title