Tool for driving pedicle screws

• US 5,946,988 A
• Filed: 07/29/1996
• Issued: 09/07/1999
• Est. Priority Date: 02/27/1992
• Status: Expired due to Term

• Current Assignee: Stryker Trauma GmbH (Stryker Corporation)
• Original Assignee: Howmedica GmbH
• Inventors: Metz-Stavenhagen, Peter
• Primary Examiner(s): MEISLIN, DEBRA S
• Application Number:
  US08/681,783
• Time in Patent Office: 1,135 Days
• Field of Search: 81/92, 81/97-99, 81/100, 81/106, 81/107, 81/109, 81/111-116, 606/104, 606/205
• US Class Current: 81/111
• CPC Class Codes: A61B 17/7082 for driving, i.e. rotating, screws or screw parts specially adapted for spinal fixation, e.g. for driving polyaxial or tulip-headed screws driving other bone screws A61B17/8875
• CPC Class Codes: A61B 17/8891 at its periphery

Abstract

A tool for driving pedicle screws into vertebrae of the human spine has a shaft preferably with a handle at one end and, at the opposite end, a holder for receiving a preferably ring-shaped head which is flattened on opposite sides. The tool has a first clamping jaw (18) secured to the shaft (12), and a second loose clamping jaw (20) including a lateral projection which is tiltably received by the first clamping jaw (18). The tool has an axially slidable actuating member (32) which is guided along the shaft (12). The front end of the actuating member (32) engages the rear end of the second clamping jaw (20) and is preferably axially urged towards the second clamping jaw (20) by a threaded driving means.

Claims

1. A tool for driving pedicle screws into a vertebra of the human spine, comprising a shaft having a handle at one end and at the opposite end having a holder for receiving a ring-shaped head of a pedicle screw, which head is flattened on opposite sides, wherein said holder comprises a first clamping jaw (18) and a second clamping jaw (20), wherein said first clamping jaw (18) is secured to the shaft (12), wherein said second clamping jaw (20) is movable and includes a lateral projection (24) which is tiltably received by the first clamping jaw (18) and wherein an axially slidable actuating member (50) is guided along the shaft (12), wherein said actuating member engages said second clamping jaw (20) so as to urge said second clamping jaw (20) to tilt toward said first clamping jaw by a thread driving means, wherein the first clamping jaw (18) includes a slot (13) and wherein said projection (24) includes a hook-shaped portion (26) engaging said first clamping jaw (18).

2. A tool of claim 1, wherein said thread driving means includes an axially slidable sleeve (32) mounted on the shaft (12) to be brought in engagement with said actuating member (50).

3. A tool of claim 2, wherein the sleeve (32) includes an inner threaded portion cooperating with a threaded portion of the shaft (12).

4. A tool of claim 3, wherein the sleeve (32) includes a knurled portion (34).

5. A tool of claim 4, wherein a spring (30) is mounted between the clamping jaws (18, 20) to urge the clamping jaws apart.

6. A tool of claim 5, wherein an actuating member is axially slidably mounted in the shaft, which actuating member coacts with the second clamping jaw (20), wherein the sleeve (32) cooperates with the rear end of the actuating member.

7. A tool for driving a pedicle screw into a vertebra of the human spine, said tool comprising:

(a) a shaft having a first end and a second end;

(b) a holder for receiving a head of a pedicle screw, said holder being located at said second end of said shaft, said holder comprising;

(1) a first clamping jaw substantially rigidly secured to said shaft and

(2) a movable second clamping jaw having a projection which is tiltably received by said first clamping jaw; and

(c) an actuating member which is axially movable along said shaft and engageable with said second clamping jaw so as to tilt said second clamping jaw toward said first clamping jaw wherein said first clamping jaw includes a guide recess and wherein said projection includes a hook-shaped portion for engaging said first clamping jaw.

8. A tool according to claim 7, wherein said actuating member is slidably mounted on said shaft so as to be able to be brought into engagement with said second clamping jaw.

9. A tool according to claim 8, and including a driving means for driving said actuating member into engagement with said second clamping jaw wherein said driving means includes an inner threaded portion for cooperating with a threaded portion of said shaft.

10. A tool according to claim 9, wherein said driving means includes a knurled portion.

11. A tool according to claim 10, and including also a spring mounted between said first clamping jaw and said second clamping jaw for urging said first clamping jaw and said second clamping jaw apart.

12. A tool according to claim 11, wherein said actuating member is axially slidably mounted on said shaft such that said actuating member can coact with said second clamping jaw and wherein said actuating member cooperates with said driving means.

13. A tool for driving a pedicle screw into a vertebra of a human spine, said tool comprising:

(a) a shaft having a first end and a second end and a slot therewithin;

(b) a holder for receiving a head of a pedicle screw, said holder being located at said first end of said shaft, said holder comprising;

(1) a first clamping jaw into which said slot extends and having a receptacle (15) therein and being substantially rigidly secured to said shaft and

(2) a movable second clamping jaw having a hook-shaped curved projection which is tiltably received within said slot in said first clamping jaw and said projection having an end which fits securely within said receptacle in said first clamping jaw but permits rotation of said curved projection within said receptacle with respect to said first clamping jaw; and

(c) a plate-shaped thrust member having a first extension extending therefrom and being axially movable within said slot located longitudinally within said shaft and being engageable at said first extension with said second clamping jaw at a single point on said curved projection so as to tilt said second clamping jaw with respect to said first clamping jaw so as to cause said holder to close and to be able to grasp said pedicle screw firmly.

14. A tool according to claim 13 and including also a driving means for driving said extension of said thrust member into engagement with said second clamping jaw at said single point on said curved projection.

15. A tool according to claim 14 and including also a handle located at said second end of said shaft, and wherein said driving means is a threaded cylinder having a first end which engages said second end of said thrust member and having a second threaded end which threads with threads on said shaft adjacent to said handle.