Spreader instrument for use in performing a spinal fusion

• US 3,916,907 A
• Filed: 06/21/1974
• Issued: 11/04/1975
• Est. Priority Date: 06/21/1974
• Status: Expired due to Term

• Current Assignee: Wendell C. Peterson
• Original Assignee: Wendell C. Peterson
• Inventors: Peterson, Wendell C.
• Primary Examiner(s): Gaudet, Richard A.
• Assistant Examiner(s): Layton, Henry S.
• Application Number:
  US05/481,637
• Time in Patent Office: 501 Days
• Field of Search: 128/20,345,33R,354,341 81/302 29/223,239
• US Class Current: 606/90
• CPC Class Codes: A61B 17/025 Joint distractors
• CPC Class Codes: A61B 17/2812 with a single pivotal connection A61B17/29 takes precedence
• CPC Class Codes: A61B 2017/0256 for the spine
• CPC Class Codes: A61F 17/00 First-aid kits
• CPC Class Codes: A61F 2/442 Intervertebral or spinal discs, e.g. resilient non-disc-shaped intervertebral inflatable pockets A61F2/441; non-disc-shaped intervertebral fusion implants A61F2/4455
• CPC Class Codes: A61F 2/446 having a circular or elliptical cross-section substantially parallel to the axis of the spine, e.g. cylinders or frustocones
• CPC Class Codes: A61F 2002/2839 Bone plugs or bone graft dowels
• CPC Class Codes: A61F 2002/30225 Flat cylinders, i.e. discs
• CPC Class Codes: A61F 2002/30433 using additional screws, bolts, dowels, rivets or washers e.g. connecting screws
• CPC Class Codes: A61F 2002/30599 stackable
• CPC Class Codes: A61F 2220/0041 using additional screws, bolts, dowels or rivets, e.g. connecting screws
• CPC Class Codes: A61F 2230/0069 cylindrical
• CPC Class Codes: A61F 2250/0063 Nested prosthetic parts
• CPC Class Codes: Y10T 29/53683 Spreading parts apart or separating them from face to face engagement

Abstract

A spreader instrument for use in spinal fusion surgery for separating adjacent vertebral bodies having a common bone assembly receiving hole pre-formed therein includes two elongated members pivotally attached intermediate their ends. A pair of partial-circularly shaped plates are attached to the pivoted members, extending outwardly from adjacent opposite free ends of the respective members. The plates are oriented with their concave faces toward each other to be adapted to be inserted into the pre-formed holes within the vertebral bodies. The plates engage the walls of the pre-formed hole in the bodies and spreads or separates the bodies as the members are pivoted, permitting a cylindrically shaped bone assembly to be axially inserted between the semi-circular plates into the hole in the vertebral bodies.

Claims

1. A spreader for separating vertebral bodies having a hole preformed therein to receive a cylindrical plug comprising, two pivotally attached elongated members, and two frustro-conically shaped curved plates, each rigidly attached to a respective one of said members, each of said plates having a first outside radius to engage the wall of said hole, and having a second inside radius smaller than said first radius for passing the bone plug, said first and second radii being upon a common center line oriented at an angle of approximately 30* from an axis along said respective elongated member.

2. The spreader of claim 1 further comprising biasing means between said members to urge said plates in a direction toward each other.

3. The spreader of claim 1 wherein said plates are mounted with their centerline axes oriented at an angle with resPect to the axis of said members, and are disposed on said elongated members to be symmetrical about a centerline axis with respect to each other when the interior faces of said plates are separated by a distance approximately equal to the diameter of said plug.

4. The spreader of claim 3 wherein the material of which the spreader is formed is stainless steel.

5. A spreader for separating two vertebral bodies having a pre-formed bone plug receiving hole, comprising:

a pair of elongated members, pivot means medially interconnecting said pair of elongated members, a pair of frustro-conically shaped arcuate plates, each rigidly attached to and outstanding from adjacent an end of a respective one of said members, each plate being of inside radius of approximately 5/8 of an inch to pass said bone plug and of outside radius of approximately 1/2 of an inch to engage one of said vertebral bodies, the center line axis of each of said plates defining an angle of about 30* with respect to the axis of the elongated member upon which it is mounted.

6. The spreader of claim 5 wherein each of said pair of arcuate plates is of approximately 3/4 of an inch in length.

7. The spreader of claim 5 wherein each of said elongated members are bent at an angle of about 30* upon its axis.

8. The spreader of claim 7 further comprising biasing means between said elongated members normally urging said plates together.

9. The spreader of claim 8 wherein the material of which the spreader is formed is stainless steel.