Implant with structure for securing a porous portion

摘要

An implant includes a head portion, an intermediate portion and an initially separate stem portion configured to engage the head portion so that at least the head portion and the stem portion cooperatively secure the intermediate portion on the implant. The implant may also include a locking mechanism configured to secure the head portion to the stem portion by a press fit or a threaded connection. The intermediate portion may include a porous metal such as tantalum.

主权项

1. An implant extending along an axis, comprising:
a head portion including a first externally threaded surface configured for engaging bone; a non-bone, porous intermediate portion, including:
a bore axially extending throughout the intermediate portion, anda porous wall extending from a porous exterior surface of the intermediate portion to a porous interior surface of the intermediate portion, the porous interior surface defining a perimeter of the bore, wherein the perimeter defines a diameter of the bore that is substantially constant in an axial direction; an initially separate stem portion configured to engage the head portion so that at least the head portion and the stem portion cooperatively secure the intermediate portion on the implant without the intermediate portion being bonded to the head and stem portions, the stem portion including a second externally threaded surface configured for engaging bone; a core having a core diameter approximately equal to the diameter of the bore, the core extending axially from at least one of the head portion, the stem portion, and both the head and the stem portions.