Bending instrument and methods of using same
Inventors
Paris, Anthony James • Wu, Gan • Glasheen Jr., Brian Patrick • Thompson, Jacob
Assignees
University of Alaska Fairbanks • University of Alaska Anchorage
Publication Number
US-9003859-B2
Publication Date
2015-04-14
Expiration Date
2031-04-01
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Abstract
A bending instrument is disclosed having first and second lever assemblies. The first lever assembly has a first lever and a first bending member, and the second lever assembly has a second lever that is configured for pivotal motion relative to the first lever. The bending instrument also has a gear assembly that is rotatively coupled to a distal portion of the first lever and which defines a lobe on which a second bending member is mounted. The second bending member of the gear assembly is configured to be angularly rotated upon the pivotal rotation of the second lever relative to the first lever.
Core Innovation
The invention is a bending instrument composed of first and second lever assemblies, a gear assembly, and specialized bending members. The first lever assembly features a first lever and a first bending member, with the distal portion designed to securely receive a rod, such as a surgical implant. The instrument further includes a support member spaced from the first bending member to define a receiving channel for the rod.
The second lever assembly has a second lever configured for pivotal motion relative to the first lever and incorporates a channel at its distal end. A gear assembly is rotatively coupled to the distal portion of the first lever, allowing rotation about a common axis. This gear assembly defines a lobe on which a second bending member is mounted such that it is substantially co-planar with the first bending member and the support member.
Upon pivotal rotation of the second lever relative to the first lever, a drive pawl in the channel of the second lever engages the gear surface of the gear assembly to rotate the second bending member about the common axis and angularly about the first bending member. The second bending member applies a bending force to a portion of the rod such that the rod is bent precisely at a point proximate the bending surface of the first bending member. The instrument addresses the need for a hand-held bending tool that achieves precise bends, ergonomic handling, and safe, efficient operation in procedures requiring the bending of surgical rods or implants.
Claims Coverage
The independent claims disclose two inventive features, each corresponding to a specific configuration of the bending instrument and method of use.
Bending instrument with first and second lever assemblies, gear assembly, and co-planar bending members
The bending instrument comprises: - A first lever assembly with a first lever, a first bending member (defining a bending surface), and a support member mounted on the distal portion of the first lever. The members extend substantially perpendicularly from a side wall, with the first bending member and support member spacing to define a receiving channel for the rod. - A second lever assembly with a second lever having a distal end with a channel, configured for pivotal motion relative to the first lever. - A gear assembly rotatively coupled to the first lever distal portion and rotatable about a common axis. The gear assembly defines a lobe with a second bending member, which is mounted substantially perpendicular to the lobe and substantially co-planar with the first bending member and support member. - A drive pawl rotatably mounted in the distal end channel of the second lever. When the second lever pivots relative to the first, the pawl engages the gear assembly to rotate the second bending member about the common axis and angularly about the first bending member. - The second bending member applies a bending force to a portion of the rod so the rod bends at a point proximate the first bending member's bending surface.
Method of bending a rod using the disclosed instrument
This method comprises: 1. Positioning the rod within the bending instrument as described above. 2. Selectively pivoting the second lever relative to the first lever to rotate the second bending member of the gear assembly about the common axis and angularly about the first bending member. 3. The second bending member applies a bending force to the rod, causing a bend at a point proximate to the bending surface of the first bending member. Sequential operation between open and closed positions of the levers can incrementally achieve the desired bending angle.
The inventive features encompass a physical configuration of a hand-held bending instrument with lever and gear assemblies designed for precise and ergonomic rod bending, as well as a method for bending rods using this instrument to achieve controlled and localized bends.
Stated Advantages
Provides the capability to make precise bends in rods or surgical implants at desired bending angles.
Offers an ergonomic, safe, and efficient hand-held design for use during surgical procedures.
Reduces the amount of force required to bend implants, and permits bends near the end of rods.
Allows both large-angle and small, incremental bends to be made with accuracy.
Minimizes inefficiencies and inaccuracies associated with conventional devices that require multiple personnel.
Documented Applications
Bending surgical implants, including spinal rods, during spinal surgery for correction of spinal instability or deformity.
Shaping surgical rods to match the desired curvature of the spine prior to attachment to vertebrae.
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