Bone Screw System

Abstract

A set of screws sized and configured for fixing a Jones fracture in a fifth metatarsal bone of a patient by preserving a bone thread path. Each screw has a low profile head on a trailing end, a thread portion on a leading portion, and a smooth shank portion between the head portion and the thread portion. A first screw has a thread major diameter of between about 4.4-4.6 mm, a second screw a thread major diameter of between about 5.4-5.6 mm, and a third screw a thread major diameter of between about 6.4-6.6 mm. The thread portion of all the screws in the set has a set of identical thread profile characteristics comprising a pitch, a leading edge angle, a trailing edge angle, a leading edge radius, a trailing edge radius, and a land. Each screw size is provided in various preferred lengths.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation of and claims priority to Provisional Patent Application Ser. No. 60 / 895,799, filed Mar. 20, 2007, which is pending.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH[0002]Not applicableREFERENCE TO A MICROFICHE APPENDIX[0003]Not applicableFIELD OF THE INVENTION[0004]The present invention relates to surgical kits, instruments, implants and methods, and more particularly to surgical kits, instruments, implants and methods for treating Jones fractures.BACKGROUND OF THE INVENTION[0005]A Jones Fracture is clinically described as a fracture approximately 12 mm from the base of the 5th metatarsal. The fracture typically extends laterally across the 5th metatarsal originating at the cuboid / 4th metatarsal joint. Background about the history, anatomy and repair of Jones fractures is provided in Fractures of the Base of the Fifth Metatarsal, Foot and Ankle Trauma, 32:171-180, 2001 (Nunley, James A, M.D.), which is i...

AI Technical Summary

Benefits of technology

[0018]Once the surgeon determines the proper screw size using the tap, the surgeon can implant the proper size final screw implant. For example, if the second tap was the correct size, the surgeon inserts the second screw through the proximal bone fragment and threads the thread portion of the second screw into the bone thread path to thereby fix the proximal bone fragment to the distal bone fragment. Likewise, if the third tap was the correct size, the surgeon implants the third screw as the final screw implant.

Problems solved by technology

In addition, several tendons attach in the area, and the tendons tend to pull the fracture apart, causing motion at the site of healing.

The surgical technique is challenging mainly because of the shape of the 5th metatarsal bone.

If the screw is too long, it pierces the medial cortex and can even stress fracture later.

If the screw diameter is too small, it will not grab the cortical bone, resulting in poor compression and fixation.

Treatment of Jones Fractures has been a difficult challenge for foot and ankle specialists.

Existing systems suffer from various drawbacks, including: screw systems that are not designed specifically for Jones fractures; screws lacking optimal dimensions for Jones fractures; lack of appropriate screw size range; lack of custom instruments; use of cannulated screws, which are not as strong in fatigue as an equivalent solid screw; and use of fully threaded screws, which do not tolerate bending stress as well as a partially threaded screw.

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