ARTHROPLASTY IMPLANTS, SYSTEMS, AND METHODS

原文（中国語）

A bone implant may include a shaft having a proximal end, a distal end, a longitudinal axis, a proximal shaft portion, and a distal shaft portion. The proximal shaft portion may include a first minor diameter, and a first helical thread disposed about the proximal shaft portion defining a first major diameter. The first helical thread may include a first concave undercut surface. The distal shaft portion may include a second minor diameter, and a second helical thread disposed about the distal shaft portion defining a second major diameter. The second helical thread may include a second concave undercut surface. The first and second concave undercut surfaces may be angled towards the distal end of the shaft. The second minor diameter may be smaller than the first minor diameter and the second major diameter may be smaller than the first major diameter.