Bone screw
AssigneeZimmer, Inc.
InventorRandall D. Ross
Life of this patent
Estimating the term…
Abstract
A guided bone screw includes proximal and distal sections threaded with different pitches in the same direction and spaced by an unthreaded intermediate section having a shorter length than the distal section with a diameter substantially equal to the major diameter of the distal section. The intermediate section diameter is greater than the minor diameter and smaller than the major diameter of the proximal section thread. The threads of both the distal and proximal sections are self-tapping. A guide bore for a guide wire extends the entire length of the screw. Two drive recesses are disposed in the proximal screw end on opposite sides of the guide bore for engagement by a two-pin screwdriver. The unthreaded intermediate section radially fills the bone bore in which it is implanted to provide lateral stability for the bone screw.
Claims18
A bone screw connecting two pieces of bone comprising:
- a distal end;
- a proximal end;
- a generally cylindrical unthreaded intermediate section having a predetermined diameter;
- a threaded proximal section extending from said proximal end to said intermediate section and having a first uniformly-pitched thread;
- a threaded distal section extending from said distal end to said intermediate section and having a second uniformly-pitched thread that is threaded in the same direction as said first threads;
- wherein the pitch of said second thread is greater than the pitch of said first thread;
- and
- wherein said second thread has a major diameter substantially equal to said predetermined diameter.
A bone screw for connecting two pieces of bone comprising;
- a distal end;
- a proximal end;
- a generally cylindrical unthreaded intermediate section having a predetermined diameter;
- a threaded proximal section extending from said proximal end to said intermediate section and having a first uniformly-pitched thread;
- a threaded distal section extending from said distal end to said intermediate section and having a second uniformly-pitched thread that is threaded in the same direction as said first thread;
- wherein the pitch of said second thread is greater than the pitch of said first thread;
- and
- wherein said threaded distal section is axially longer than said intermediate section.
A bone screw for connecting two pieces of bone comprising:
- a distal end;
- a proximal end;
- a generally cylindrical unthreaded intermediate section having a predetermined diameter;
- a threaded proximal section extending from said proximal end to said intermediate section and having a first uniformly-pitched thread;
- a threaded distal section extending from said distal end to said intermediate section and having a second uniformly-pitched thread that is threaded in the same direction as said first thread;
- wherein the pitch of said second thread is greater than the pitch of said first thread;
- wherein said first thread is self-tapping at its end adjacent said intermediate section and said second thread is self-tapping at said distal end;
- and
- wherein said first thread has a major diameter larger than said predetermined diameter and a minor diameter smaller than said predetermined diameter.
Dependencies are inferred from the claim text.