Artificial joints for medical purposes; surgical implants comprised of artificial materials; artificial skin for surgical purposes; artificial hairs for medical purposes in the nature of hair prostheses; artificial limbs; dialyzers; artificial breasts; prosthetic ligaments; artificial jaws; vertebral orthopedic apparatus; medical apparatus and instruments for use in surgery; endoprostheses; artificial bones for implantation; artificial cartilage; bone substitutes for surgical use; bone retrac...