Single action locking pedicle screwdriver

Patent metadata

Field	Value
Publication number	US-9642654-B2
Application number	US-201414305254-A
Country	US
Kind code	B2
Filing date	Jun 16, 2014
Priority date	Jun 16, 2014
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

An instrument for attaching a driver shaft to a screw assembly using a thrusting motion. The instrument has a main shaft, a locking tube, and a driver shaft. The locking tube is slidably mounted within the main shaft and the driver shaft is slidably mounted within the locking tube. The locking tube is configured to urge a jaw assembly of the instrument into a tensioned engagement with a body member of the screw assembly. A locking mechanism is also included and is configured to lock the driver shaft in a fixed position relative to the locking tube. The locking mechanism may be configured to lock the driver shaft with respect to the locking tube after a distal end of the main shaft engages the screw assembly using the single action.

First claim

We claim:

1. An instrument for attachment to a screw assembly using a single action motion, said instrument further configured to insert a screw into a surgical site, said instrument comprising:
a main shaft having a distal end, a locking tube, and a driver shaft, said locking tube slidably mounted within said main shaft and said driver shaft slidably mounted within said locking tube; and
a locking mechanism comprising a locking plate with an aperture, said locking plate attached to said locking tube and said driver shaft extending through said aperture and completely encircled by said locking plate, said locking mechanism configured to lock said driver shaft in a fixed position in relation to said locking tube by translating a distal movement of one of said main shaft or said locking tube with respect to said driver shaft.

2. The instrument of claim 1 , wherein said locking plate has a tilt position, said locking plate binding said driver shaft in said fixed position when in said tilt position.

3. The instrument of claim 2 , wherein said distal end of said main shaft has a pair of opposing jaws having a contoured edge dimensioned to engage a body member of the screw assembly.

4. The instrument of claim 3 , wherein said locking tube slides between said pair of opposing jaws during translating the distal movement of one of said main shaft or said locking tube with respect to said driver shaft.

5. The instrument of claim 4 , wherein said locking tube slid between said pair of opposing jaws locks said pair of opposing jaws to the body member of the screw assembly.

6. The instrument of claim 1 , further comprising a preload mechanism configured to urge a distal end of said driver shaft towards a screw head of the screw assembly and pull a body member of the screw assembly away from said distal end of said driver shaft.

7. The instrument of claim 6 , wherein said preload mechanism is a jaw assembly tensioner configured to pull a pair of opposing jaws attached to the body member of the screw assembly away from said distal end of said driver shaft.

8. The instrument of claim 7 , wherein said jaw assembly tensioner has a cam screw attached to said locking tube and a locking ramp within said main shaft, said cam screw moving along said locking ramp configured to pull said pair of opposing jaws away from a distal end of said driver shaft after said locking tube locks said pair of opposing jaws to the body member of the screw assembly.

9. The instrument of claim 8 , further comprising a housing coupled to said main shaft and dimensioned to be grasped by a surgeon and assist in the single action motion.

10. A screw assembly and an instrument for attachment to the screw assembly using a single action motion, comprising:
a screw with a body member mounted onto said screw, the body member having a slot with an outer contoured edge;
a housing;
a main shaft having a proximal end coupled to said housing and a distal end with a screw jaw assembly, said screw jaw assembly having a pair of opposing jaws, each of said pair of opposing jaws having an outer contoured edge that is complementary with said outer edge of said slot;
a locking tube slidably disposed within said main shaft and having a proximal end coupled to said housing and a distal end configured to engage said screw jaw assembly by sliding between said pair of opposing jaws and exerting an outward force therebetween, said outward force between said pair of opposing jaws engaging said outer contoured edge of each of said pair of opposing jaws with said outer contoured edge of said slot and attaching said pair of opposing jaws to the screw assembly; and
a drive shaft slidably disposed within said locking tube and having a distal end configured to engage the screw head of the screw assembly.

11. The screw assembly and instrument of claim 10 , wherein said outer contoured edge of said slot of said body member has an indentation.

12. The screw assembly and instrument of claim 11 , wherein said outer contoured edge of each of said pair of opposing jaws has a projection that is complementary in shape with said indentation of said outer contoured edge of said slot of said body member.

13. The screw assembly and instrument of claim 10 , further comprising a locking mechanism configured to lock said driver shaft in a fixed position relative to said locking tube, said locking mechanism selected from the group consisting of a locking plate that binds against said driver shaft, a spring loaded detent, and a pin and groove catch.

14. The screw assembly and instrument of claim 13 , wherein said locking mechanism is said locking plate with a tilt position and an un-tilt position, said locking plate having an aperture and said driver shaft extending through said aperture.

15. The screw assembly and instrument of claim 14 , wherein said locking plate in said tilt position binds an edge of said aperture against said driver shaft and locks said driver shaft in said fixed position relative to said locking tube.

16. The screw assembly and instrument of claim 15 , wherein said locking plate is a pair of locking plates, each of said pair of locking plates having an aperture with said driver shaft extending therethrough, each of said pair of locking plates also have said tilt position and said un-tilt position.

17. The screw assembly and instrument of claim 10 , further comprising a preload mechanism configured to urge a distal end of said driver shaft towards the screw head of the screw assembly and pull a body member of the screw assembly away from said distal end of said driver shaft.

18. The screw assembly and instrument of claim 17 , wherein said preload mechanism is a jaw assembly tensioner configured to pull a pair of opposing jaws attached to the body member of the screw assembly away from said distal end of said driver shaft.

19. The screw assembly and instrument of claim 18 , wherein said jaw assembly tensioner has a cam screw attached to said locking tube and a locking ramp within said main shaft, said cam screw moving along said locking ramp configured to pull said pair of opposing jaws away from a distal end of said driver shaft after said locking tube locks said pair of opposing jaws to the body member of the screw assembly.

Assignees

• Alphatec Spine Inc

Inventors

• Reimels William
• Stevenson Tara

Classifications

• A61B17/7082 Primary

  for driving, i.e. rotating, screws or screw parts specially adapted for spinal fixation, e.g. for driving polyaxial or tulip-headed screws · CPC title

• A61B17/7032

  Screws or hooks with U-shaped head or back through which longitudinal rods pass · CPC title