Someone had his kneecap removed by surgery and replaced by an artificial one, what should he do with the old bones and cartilage removed. Is a Cohen allowed to be in the same room as these removed pieces are?

Although Shulchan Aruch (Y.D. 369) and Poskim rule that a Cohen cannot be under the same roof of even an ‘Ever’ or removed member of a living person, it does not apply to a partial bone without flesh. On question 3406 in regard to the burial of limbs we wrote: Poskim disagree. Pischei Teshuva (Y. D. 361: 1) quoting Shevus Yaakov (2: 101) debates whether one is obligated to do Kevura on limbs, that were detached from the living. (See also Gesher Hachaim p. 145, Minchas Chinuch 537, Igros Moshe (Y,.D; 1: 231-232 and others). Horav Shlomo Miller’s Shlit’a opinion is that they should be buried, preferably in the kever where the afflicted is to use eventually. No ceremony is needed. On question 3407 we added; Poskim disagree if there is a mitzva of burial on every part of the body even before the death of the individual. Mishne Lemelech (end of H. Avel) and others maintain that there is no burial obligation, to anything less than the head and majority of the body. (Based on the Yerushalmi Nazir 7: 1 and Semachos 4: 8). Tosafos Yom Tov (Shabbos end of p. 10) opine that even a ‘Kezais’ (or olive volume) of a cadaver, should be buried by itself. Gesher Hachaim (ch. 16) is of the opinion that all agree that when possible these parts should be buried with the main body. Noda Beyehuda (1: Y.D. 90) regarding the burial of a fetus argues that the liability of burial of body parts is to avoid incurring in the prohibition of benefiting from the death. While Gesher Hachaim (ibid) indicates that it is mainly to avoid the prohibition of Cohanim to come in contact or close to parts o a cadaver. Chassam Soffer (336) adds that it is due to the inherent holiness of the body of a person, which is similar to a Sefer Torah. However, Shevus Yaakov (2: 101), Maharil Diskin, Tsitz Eliezer (10: 25) are of the opinion that even if there is no obligation, the minhag is to bury them. And on the onset and when possible all the body parts should be buried together. Horav Shlomo Miller’s Shlit’a opinion is that the burial obligation applies mainly to body members that have bones in them.