Metal head fatigue fracture and coin like metal corpora libera in two cases. Is the reason -3 size head usage?

We report a very rare and extraordinary complication, metal head fatique fracture at the site of the socket tip deep border and coin like metal corpora libera in two cases with metal on metal total hip prosthesis. Catastrophic wear at the site of the deep border of the collum socket and coin like loose body originating from the crom-cobalt head resulted with metallosis, osteolysis and failure. The outcomes of the revision operations were satisfactory and the patients returned to their daily activity without discomfort in their hip. Headwear is a well-known result of the metal on metal articulation and may present with instability, metallosis, pain and mechanical symptoms. These incidents might be important to investigate for tribological performance of hip implants in biotribology science. We believe -3 sized metal head usage might be the reason of this catastrophic complication their usage should be avoided in metal on metal artroplasties