Compound hinged rod bender

[0001] This patent application is a Continuation of U.S. patent application Ser. No. 13/219,295 filed on Aug. 26, 2011, now allowed, which claims priority to U.S. Provisional Application No. 61/377,343 filed on Aug. 26, 2010. The content and subject matter of these applications are hereby incorporated by reference in their entirety, including all text and figures, for all purposes.

[0002] The present disclosure generally relates to a device for bending elongated spinal rods and plates.

[0003] Bones and bony structures are susceptible to a variety of weaknesses that can affect their ability to provide support and structure. Weaknesses in bony structures may have many causes, including degenerative diseases, tumors, fractures, and dislocations. Advances in medicine and engineering have provided doctors with a plurality of devices and techniques for alleviating or curing these weaknesses. Typically, weaknesses in the spine are corrected by using devises that fuse one or more vertebrae together. Devices such as rods and plates are utilized to stabilize adjacent vertebrae. However, these rods and plates need to be bent or modified to accommodate the anatomy. Therefore, there is a need for a device which allows a surgeon to easily and accurately bend spinal rods and plates prior to insertion in to the body.

[0004] The present invention discloses a compound rod bender having a first handle arm and a second handle arm coupled to each other at a first pivot point. A body portion is coupled to the first handle arm at a second pivot point and the second handle arm is coupled to a third pivot point. The body portion includes a first and a second distal arm that are configured with first and second rolling elements which are coupled to the distal ends of the first and second distal arms. There is also provided a barrel positioned on a center portion of the body portion. A spinal rod is positionable between the first and second rolling elements and the barrel for bending when the first and second handle arms are actuated.

[0011] While it is apparent that the invention disclosed herein is well calculated to fulfill the objects stated above, it will be appreciated that numerous modifications and embodiments may be devised by those skilled in the art.

[0012] FIGS. 1 and 2 illustrate a compound rod bender 10 in a closed position and in an open position. FIGS. 3-5 illustrate a top view and the bottom view of the rod bender in greater detail. Turning to FIGS. 1-5, the rod bender 10 comprises a first handle arm 12 and a second handle arm 14 that are coupled at a pivot point 16 and pivot points 18 and 20. The first handle arm 12 and the second handle arm 14 are connected to the body 21 of the compound rod bender 10 at pivot points 18 and 20, respectively. The rod bender 10 also comprises a first distal arm 22 and a second distal arm 24 which are configured about pivot point 26. The body 21 of the rod bender 10 is further provided with a first rolling element 28 and a second rolling element 30. The first rolling element 28 is positioned on the distal end of the first distal arm 22 and is configured to be rotatable. The second rolling element 30 is positioned on the distal end of the second distal arm 24 and is configured to be rotatable. The body 21 further provides a rotatable barrel 32 positioned below the first and second rolling elements 28 and 30. The rolling elements 28 and 30 are configured with rotating outer bearing portions which are substantially circular which are coupled to the first and second distal arms by a pin.

[0013] The barrel 32 is provided to support a rod when the rod is positioned between the rolling elements and the distal end of the barrel 32. The barrel 32 which is positioned on the pivot point 26 acts as a hinge between the two distal arms 22 and 24. The base portion of the barrel 32 includes a plurality of bending surfaces. Each bending surface can be selectively positioned into the desired operating position. The variety of bending surface contours enables the rod bender to accommodate different size rods, as well as provides for varying severities or contours of bend to the rod. The barrel 32 can be selectively rotated to cause the desired bending surface to be in appropriate position. During the operation of the rod bender 10, when the first and second handle arms 12 and 14 are actuated, a rod that is positioned in the rod bender is bent to accommodate the surgeon's preference. The radius of the bend in the rod can be manipulated by turning the barrel to various positions, as the circumference of the barrel is configured with different radii.

[0014] The rod bender of the present invention is operated as follows: First, the desired bending surface on the barrel is rotated and engaged into the operating position. The selected surface of the barrel faces toward the distal end of the instrument and operator positions a spinal rod between the rolling elements and the barrel after the handle arms of the instrument are moderately separated. This causes the distal arms to rotate in an arc upward and inward providing vertical clearance between the two distal arms and the barrel. After clearance is obtained, a suitable rod is then placed onto the selected bending surface of the barrel and the under the first and second rolling elements. A slight grip by the hands of the user will bring the distal arms and the rolling elements down and against the rod trapping it against the bending surface of the barrel. Additional force will bend the rod around the bending surface of the barrel. If a more or less severe bend is desired, the barrel can be rotated so that difference bending surface can be used.

[0015] The present invention includes the use of a compound hinge to increase the instruments mechanical advantage. The introduction of three additional pivot points and two lever arms will increase the instrument's output force dramatically, reducing the force required to contour a surgical rod when compared to a traditional rod bender. The relationship between the two sets of lever arms is directly related to the instrument's output force. It uses a compound joint to increase the bending force.

[0016] The various features and embodiments of the invention described herein may be used interchangeably with other feature and embodiments. Finally, while it is apparent that the illustrative embodiments of the invention herein disclosed fulfill the objectives stated above, it will be appreciated that numerous modifications and other embodiments may be devised by one of ordinary skill in the art. Accordingly, it will be understood that the appended claims are intended to cover all such modifications and embodiments which come within the spirit and scope of the present invention.