System for stabilizing the spine and reducing spondylolisthesis

• US 5,531,745 A
• Filed: 11/14/1994
• Issued: 07/02/1996
• Est. Priority Date: 03/11/1993
• Status: Expired due to Fees

• Current Assignee: Salut, Ltd.
• Original Assignee: Danek Medical, Inc.
• Inventors: Ray, R. Charles
• Primary Examiner(s): TUCKER, GUY V
• Application Number:
  US08/339,580
• Time in Patent Office: 596 Days
• Field of Search: 606/61, 606/60, 606/69, 606/71, 606/105, 606/72, 606/73, 623/17, 623/16
• US Class Current: 606/261
• CPC Class Codes: A61B 17/7043 with a longitudinal element fixed to one or more transverse elements which connect multiple screws or hooks
• CPC Class Codes: A61B 17/7055 connected to sacrum, pelvis or skull

Abstract

A system for achieving reduction of curvature of the lumbar region of the spine associated with spondylolisthesis includes transverse plates affixed to vertebrae L4 and L5 and sacral plates affixed to opposite sides of the sacrum. These plates in combination with the longitudinal plate along the posterior anterior plane in which the spinous processes lie allows for effective reduction of the curvature and secure fixation of this region of the spine. The transverse plates include textured surfaces which allow them to mate in a manner which prevents undesirable slippage therebetween. The system is also compact and does not interfere with the paraspinal muscles which run along either side of the spinous processes.

Claims

1. A system for stabilizing the lumbar region of the spine and reducing displacement of the spine resulting from spondylolisthesis comprising:

first and second transverse plates for securing to vertebrae L4;

third and fourth transverse plates for securing to vertebrae L5, said first, second, third, and fourth transverse plates each including at one end an eye for receiving a pedicle screw along a first axis and extending from the eye two substantially parallel spaced-apart fingers of substantially equal length, said spaced-apart fingers including a posterior surface and an opposing anterior surface, the anterior surface of said spaced-apart fingers of said first and third transverse plates being textured and the posterior surface of said spaced-apart fingers of said second and fourth transverse plates being textured;

first and second sacral plates, said sacral plates each including a substantially planar body having a plurality of bores for rigidly fixing said sacral plates independently to opposite lateral portions of a sacrum, extending from each body are two spaced-apart fingers of substantially equal length having posterior and opposing anterior surfaces, the anterior surface of the spaced-apart fingers of said first sacral plate being textured and the posterior surface of the spaced-apart fingers of said second sacral plate being textured;

longitudinal member including a superior end and an inferior end connected by spaced-apart members, said superior and inferior end and said spaced-apart members defining a slot in said longitudinal member;

a first fastener for securing the first and second transverse plates to one another and to the longitudinal member, the first fastener extending between the spaced-apart fingers of the first and second transverse plates and between the spaced-apart members of the longitudinal member when fastened;

a second fastener for securing the third and fourth transverse plates to one another and to the longitudinal member, the second fastener extending between the spaced-apart fingers of the third and fourth transverse plates and between the spaced-apart members of the longitudinal member when fastened; and

a third fastener for securing the first and second sacral plates to one another and to the longitudinal member, the third fastener extending between the spaced-apart fingers of the first and second sacral plates and between the spaced-apart members of the longitudinal member.

2. The system of claim 1, wherein the textured surfaces of said spaced-apart fingers include a repetitive pattern having an amplitude sufficient to prevent slippage between the textured surfaces when secured together by said fasteners.

3. The system of claim 1, wherein a longitudinal centerline runs parallel to and between the spaced-apart fingers of said first and second transverse plates, said first axis being offset from said centerline such that said longitudinal centerline does not intersect said first axis.

4. The system of claim 1, wherein a longitudinal centerline runs parallel to and between the spaced-apart fingers of said third and fourth transverse plates, said first axis being offset from said centerline such that said centerline does not intersect said first axis.

5. A system for stabilizing the lumbar region of the spine and reducing displacement of the spine resulting from spondylolisthesis comprising:

first and second transverse plates for securing to vertebrae L4;

third and fourth transverse plates for securing to vertebrae L5, said first, second, third, and fourth transverse plates each including at one end an eye for receiving a pedicle screw along a first axis and extending from the eye two substantially parallel spaced-apart fingers of substantially equal length, said spaced-apart fingers including a posterior surface and an opposing anterior surface, the anterior surface of said spaced-apart fingers of said first and third transverse plates being textured and the posterior surface of said spaced-apart fingers of said second and fourth transverse plates being textured;

first and second sacral plates, said sacral plates each including a substantially planar body having a plurality of bores for rigidly fixing said sacral plates independently to opposite lateral portions of a sacrum, extending from each body are two spaced-apart fingers of substantially equal length having posterior and opposing anterior surfaces, the anterior surface of the spaced-apart fingers of said first sacral plate being textured and the posterior surface of the spaced-apart fingers of said second sacral plate being textured;

longitudinal member including a superior end and an inferior end connected by spaced-apart members, said superior and inferior end and said spaced-apart members defining a slot in said longitudinal member; and

fasteners for Securing the spaced-apart fingers of said first, second, third, and fourth transverse plates, and the spaced-apart fingers of said first and second sacral plates to said longitudinal member;

a carriage bolt that includes a head, a flange for fitting into said slot, and a threaded portion, said flange located between said head and said threaded portion and having a thickness substantially equal to the combined thickness in a posterior to anterior direction of the spaced-apart fingers of said first and second transverse plates;

a primary nut including a textured posterior surface and an opposing textured anterior surface;

a washer, said washer including an annular body with an outer perimeter and two opposing flanges extending in a posterior direction from opposite edges of said washer; and

a secondary nut.

6. A system for stabilizing the lumbar region of the spine and reducing displacement of the spine resulting from spondylolisthesis, comprising:

a first transverse plate adapted for connection to a left pedicle of a first vertebra, the first transverse plate including a first elongated slot therein;

a second transverse plate adapted for connection to a right pedicle of the first vertebra, the second transverse plate including a second elongated slot therein;

a third transverse plate adapted for connection to a left pedicle of a second vertebra, the third transverse plate including a third elongated slot therein;

a fourth transverse plate adapted for connection to a right pedicle of the second vertebra, the fourth transverse plate including a fourth elongated slot therein;

a longitudinal member having a longitudinal slot therein;

a first fastener for securing the first and second transverse plates to one another and to the longitudinal member, the first fastener passing through the first, second, and longitudinal slots when fastened;

a second fastener for securing the third and fourth transverse plates to one another and to the longitudinal member, the second fastener passing through the third, fourth, and longitudinal slots when fastened, and

wherein the first and second transverse plates include respective first and second textured surfaces, the first and second textured surfaces adapted to engage one another when the first fastener is fastened; and

the third and fourth transverse plates include respective third and fourth textured surfaces, the third and fourth textured surfaces adapted to engage one another when the second fastener is fastened.

7. The system of claim 6, wherein the first, second, third and fourth textured surfaces include a repetitive pattern having an amplitude sufficient to substantially prevent slippage between engaged textured surfaces when fastened together by the first and second fasteners.

8. The system of claim 6, further comprising:

a first sacral plate adapted for connection to a left pedicle of a sacrum, the first sacral plate including a fifth slot therein;

a second sacral plate adapted for connection to a right pedicle of the sacrum,

the second sacral plate including a sixth slot therein; and

a third fastener for securing the first and second sacral plates to one another and to the longitudinal member, the third fastener passing through the fifth, sixth, and longitudinal slots when fastened.

9. The system of claim 6, wherein the first fastener comprises:

a first carriage bolt that includes a first head, a first flange for fitting into the first and second slots, and a first threaded portion, the first flange located between the first head and the first threaded portion and having a thickness substantially equal to a combined thickness of the first and second transverse plates;

a first primary nut;

a first washer, the first washer including an annular body having a surface, and two opposing flanges extending in a direction perpendicular to the surface; and

a first secondary nut.