Patent ID: 11857233
Assignee: WARSAW ORTHOPEDIC, INC.
Field: Medical technology (Instruments)
Classification: CPC A  B | IPC A

Claim 19:
20. 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 having a surface and a thickness disposed about the core, the wall defining a plurality of spaced apart struts, the shaft comprising a lattice positioned between the struts, the struts having a solid surface relative to the lattice, the distal portion comprising a second thread, the struts each extending between adjacent crests of the second thread, a portion of the second thread extending outwardly from the wall, the first thread including a pitch and the second thread including an increased pitch and an equal lead between thread turns, 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 portion 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.