As for metal-on-metal replacement hips (with both cups and heads made of cobalt chromium), those also wear out at slower rates, and are well suited to the young and those who engage in strenuous exercise. Yet because they release metal ions, which can damage fetuses and kidneys, patients should carefully weigh their pros and cons.
另一種金屬對金屬介面的材質（股骨頭及髖臼內襯皆為鈷鉻鉬合金），也可以降低磨損率，適合需要從事粗重工作者或年輕病患，但因會釋放金屬離子，有造成胎兒損傷或腎臟損傷之虞，民眾在選擇時應一併考量利弊得失。