Filing Information

Inventor(s)	Randall J. Huebner ·
Assignee(s)	Acumed, Inc. ·  View assignee updates
Attorney/Agent(s)	Kolisch, Hartwell, Dickinson, McCormack & Heuser ·
Primary Examiner	Michael Buiz ·
Assistant Examiner	Lien Ngo ·
Application Number	US9034046
Filing date	03/03/1998
Issue date	10/12/1999
Predicted expiration date	01/21/2013
U.S. Classifications	606/73  · 606/72  ·
International Classifications	A61B 1756  ·
Kind Code	A
International Classifications	60673;72;74;75;59-65;104;105 ·
Related U.S. Application Data	CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of U.S. patent application Ser. No. 08/781,571 filed Jan. 10, 1997, which is a continuation-in-part of U.S. patent application Ser. No. 08/506,469 filed Jul. 25, 1995, which is a continuation-in-part of U.S. patent application Ser. No. 08/332,445 filed Oct. 31, 1994, now U.S. Pat. No. 5,562,672 issued Oct. 8, 1996, which is a continuation of U.S. patent application Ser. No. 08/007,196, filed Jan. 21, 1993. U.S. patent application Ser. No. 08/506,469 is also a continuation-in-part of PCT Application Number PCT/US94/00738, filed Jan. 19, 1994, which claims priority from U.S. patent application Ser. No. 08/007,196, filed Jan. 21, 1993.

Patent Family

Abstract

A bone screw having a continuously varying pitch includes a tapered root portion having a relatively small diameter on a leading end of the screw and a larger trailing diameter. The pitch of the screw decreases between the leading and trailing ends thus causing the bone fragments in a fracture to be drawn together when the screw is installed across the fragments. The radially outer diameter of the threads increases between the leading and trailing ends thus causing each successive thread portion to cut into bone radially outwardly from the preceding thread portion thereby providing uncut bone in which the succeeding threads can gain purchase.

Independent Claims | See all claims (35)

1. 1. A method of joining first and second objects, the method comprising:providing a headless screw having an elongate root portion, a leading end and a trailing end, the screw further having a screw thread formed over at least a portion of the root portion, the screw thread have a pitch measured between corresponding points on consecutive thread crests which is larger toward the leading end and smaller toward the trailing end, the screw thread further having a diameter which is larger toward the trailing end and smaller toward the leading end;introducing the leading end of the screw into the first object through a first surface of the first object;rotating the screw to drive the leading end of the screw forward through the first object and into the second object until the trailing end of the screw is disposed beneath the first surface of the first object with a portion of the screw thread being disposed in each object to thereby secure the two objects together.
2. 3. A method of urging first and second objects toward each other, the method comprising:providing a screw having an elongate root portion, a leading end and a trailing end, the screw further having a screw thread formed over at least a portion of the root portion, the screw thread having a pitch measured between corresponding points on consecutive thread crests which is larger toward the leading end and smaller toward the trailing end, wherein the pitch varies substantially continuously over at least a portion of the thread, the screw thread further having a diameter which is larger near the trailing end and smaller near the leading end;introducing the leading end of the screw into the first object through a first surface of the first object;driving the leading end of the screw forward through the first object and into the second object until the portion of thread having substantially continuously varying pitch is disposed a partially in the first object and partially in the second object.
3. 6. A method of urging first and second objects toward each other, the method comprising:providing a screw having an elongate root portion, a leading end and a trailing end, the screw further having a screw thread formed over at least part of the root portion and having a pitch measured between corresponding points on consecutive thread crests;introducing the leading end of the screw into the first object through a first surface of the first object;driving the leading end of the screw forward through the first object and into the second object until a leading portion of the screw thread is disposed in the second object and a trailing portion of the screw thread is disposed in the first object, where the pitch of the screw thread is larger toward the leading end and smaller toward the trailing end and the diameter of the screw thread varies in each portion and is smaller toward the leading end and larger toward the trailing end.
4. 8. A method of urging first and second objects toward each other, the method comprising:providing a screw having an elongate root portion, a leading end and a trailing end, the screw further having a screw thread formed over at least part of the root portion, the screw thread having a pitch measured between corresponding points on consecutive thread crests which is larger toward the leading end and smaller toward the trailing end and a diameter which is smaller toward the leading end and larger toward the trailing end, at least along a first portion of the screw the pitch gradually increases as the diameter gradually decreases;introducing the leading end of the screw into the first object;driving the leading end of the screw forward through the first object and into the second object until the leading end of the screw is disposed in the second object and first portion spans a junction between the first and second objects and with part of the first portion of the screw disposed in each object.
5. 12. A method of drawing together first and second bone portions, the method comprising:boring a hole into both bone portions, where the hole extends through the first bone portion, across a junction between the bone portions and into the second bone portion;inserting a leading end of a screw into the hole in the first bone portion, where the screw has a pitch measured between corresponding points on consecutive crests of the thread that is larger near the leading end and smaller near the trailing end and which changes substantially continuously over at least a portion of the screw; andscrewing the screw into the hole until the portion of the screw with substantially continuously changing pitch is disposed across the junction between the bone portions with a portion of the screw thread being disposed in each object to thereby secure the two objects together.
6. 22. A method for drawing together first and second bone portions, said method comprising:using a drill bit to bore a hole into both bone portions with a central portion of the hole having both bone portions disposed thereacross;inserting the nose of a screw into the hole, said screw having a thread pitch measured between substantially all corresponding points of consecutive threads which decreases continuously from a leading end to a trailing end of the screw and a root portion having a substantially constant tapered surface which increases continuously from the leading end to the trailing end;screwing the screw into the hole; andcontinuing screwing until all of the screw is received within the bore.
7. 28. A method for using a screw having a thread pitch measured between substantially all corresponding points of consecutive threads which decreases continuously from a leading end to a trailing end of the screw, said method comprising the steps of:boring axial holes into first and second bone portions;inserting the nose of the screw into an end of one of the holes;screwing the screw into the holes; andstopping screwing when the thread is received in both holes.