Bone screw and method of manufacture
AssigneeWarsaw Orthopedic, Inc.
InventorsDale A. Tempco, Rodney Ray Ballard, Keith E. Miller, William Alan Rezach
Life of this patent
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Abstract
A bone screw comprises a shaft defining a longitudinal axis and a minor diameter. The shaft including a core having an angled surface relative to the axis. The angled surface extending from the minor diameter adjacent a proximal portion of the shaft to a distal portion of the shaft, and a wall disposed about the angled surface. The wall including at least one thread having an external thread form. In some embodiments, systems, spinal constructs, surgical instruments and methods are disclosed.
Claims21
1-20. (canceled)
A bone screw comprising a shaft defining a longitudinal axis, the shaft including a proximal portion and a distal portion, the proximal portion comprising a first thread, the first thread being made entirely from a first material, the first material being non-porous, the distal portion comprising a core, the shaft including a wall disposed about the core, the distal portion comprising a second thread, a portion of the second thread extending outwardly from the wall, the second thread comprising a second material, the second material being porous.
A bone screw comprising a shaft defining a longitudinal axis, the shaft including a proximal portion and a distal portion, the proximal portion comprising a first thread, the first thread being made entirely from a first material, the distal portion comprising a core, the shaft including a wall disposed about the core, the distal portion comprising a second thread, a portion of the second thread extending outwardly from the wall, the second thread including an increased pitch and an equal lead between thread turns than the first thread, a root of the second thread is made from the first material and a crest of the second thread includes a leading portion and a trailing portion, the leading portion being made from a second material, the trailing edge being made from the first material, the second material being porous, the second material having a density less than a density of the first material.
A bone screw comprising a shaft defining a longitudinal axis, the shaft including a proximal portion and a distal portion, the proximal portion comprising a first thread, the first thread being made entirely from a first material, the distal portion comprising a core, the shaft including a wall disposed about the core, the distal portion comprising a second thread, a portion of the second thread extending outwardly from the wall, the second thread including an increased pitch and an equal lead between thread turns than the first thread, a root of the second thread is made from the first material and a crest of the second thread includes a leading portion and a trailing portion, the leading portion being made from a second material, the trailing edge being made from the first material, the second material being porous, the first material having a density between 0.5 through 10.5 grams per cubic centimeter, the second material having a density similar to cancellous bone tissue, the density of the second material being less than the density of the first material.
Dependencies are inferred from the claim text.