I am not 100% certain this bone is human: too much carving has obscured the silhouette. It does resemble superficially the Humerus (shoulder bone), but I would not bet my house (or even $100) on it.
Recently, somebody sold a Naga Dao with a 100% real human Femur (Thigh bone) for a handle.
Call it Eurocentric (
) squeamishness or anything else equally PC and offensive at the same time, but I would never, ever bring a thing like that into my house! Human remnants need to be buried, not re-used. Let the headhunters do what they want, but I shall stay out of it.