Crack-resistant polycarbonate urethane polymer prostheses

An implantable medical prosthesis article of manufacture including a segmented polycarbonate urethane polymer fiber, comprising:

• an implantable prosthesis including an extruded fiber formed in air from a polycarbonate urethane solution including a polar organic solvent and a polycarbonate urethane polymer, said polycarbonate urethane polymer including:
• a polymeric backbone having recurring groups selected from the group consisting of urethane groups, urea groups, carbonate groups and combinations thereof;
• said polycarbonate urethane polymer is a reaction product of a polycarbonate glycol reactant having terminal hydroxy groups, a diisocyanate reactant having terminal isocyanate groups, and a chain extender reactant having terminal hydroxyl or amine groups, wherein the polymer reaction product has a hardness in the range of about Shore 75A to about Shore 75D;
• and
• whereby said polycarbonate urethane polymer prostheses is crack-resistant when implanted, and surface cracking and breakage of the extruded fibers are substantially prevented during in vivo implantation for in excess of six months.