BONE FIXATION SYSTEM WITH CURVED PROFILE THREADS
A bone fastener for use in orthopedic surgery for fixing an implant to bone has a threaded or unthreaded shaft configured to engage bone and a head having a thread on an outer surface to engage the implant. The thread on the head of the fastener has a profile in cross section that includes peaks with a curved shape.
1 . A bone fastener for use in orthopedic surgery for fixing an implant to bone, comprising:
a shaft configured to engage bone; and
a head formed on the shaft, the head having a thread on an outer surface to engage the implant, wherein the thread has a profile in cross section including peaks, wherein the peaks have a curved shape.
2 . The bone fastener according to claim 1 , wherein each curved peak forms an arc segment.
3 . The bone fastener according to claim 2 , wherein a radius of curvature (r) of the arc segment is between 0.05 mm and 3.0 mm.
4 . The bone fastener according to claim 2 , wherein an angular range (w) of the arc segment is between 30° and 200°.
5 . The bone fastener according to claim 3 , wherein an angle (k) between a plane (p) including a core diameter of the head and a tangent (t) of the arc segment is between −10° and 90°.
6 . The bone fastener according to claim 1 , wherein the curved peaks are provided immediately adjacent to each other.
7 . The bone fastener according to claim 1 , wherein the curved peaks are separated from each other by circumferential valleys having a planar or rounded profile.
8 . The bone fastener according to claim 1 , wherein the thread of the head includes curved flanks.
9 . The bone fastener according to claim 1 , wherein the thread of the head is a single or multiple thread.
10 . The bone fastener according to claim 1 , wherein the head has a conical or curved shape.
11 . The bone fastener according to claim 10 , wherein the head has a constant core diameter and wherein an outer diameter of the thread of the head gradually tapers.
12 . The bone fastener according to claim 10 , wherein the core of the head has a conical or curved shape and wherein an outer diameter of the thread of the head gradually tapers.
13 . An implant system for use in orthopedic surgery for fixation of bone, comprising:
an implant having an upper surface and a lower surface;
at least one hole extending through the implant upper surface and lower surface; and
at least one bone fastener comprising a shaft configured to engage bone and a head having a thread on an outer surface to engage the implant, wherein the thread has a profile in cross section including peaks, wherein the peaks have a curved shape.
14 . The implant system according to claim 13 , wherein the at least one hole includes a threaded portion configured to mate with the thread of the head of the at least one bone fastener.
15 . The implant system according to claim 13 , wherein the at least one hole includes an upper unthreaded portion and a lower threaded portion configured to mate with the thread of the head of the at least one bone fastener.
16 . The implant system according to claim 15 , wherein the upper portion of the at least one hole has an inward taper having a conical or curved shape.
17 . The implant system according to claim 15 , wherein the threaded portion of the at least one hole tapers inwardly toward the lower surface of the implant.
18 . The implant system according to claim 14 , wherein the threaded portion of the at least one hole has a multiple thread.
19 . The implant system according to claim 13 , wherein the at least one hole has a central axis which is oblique relative to a vertical axis of the implant).
20 . The implant system according to claim 13 , wherein the implant is configured as a bone plate and wherein the bone fastener is configured as a bone screw.