Synthes Holding AG (formerly Synthes-Stratec) is a multinational medical device manufacturer based in Solothurn, Switzerland and West Chester, Pennsylvania, United States. It is the world's largest maker of implants to mend bone fractures, and also produces surgical power tools and advanced biomaterials.In June 2012 Synthes was sold by its chairman, former CEO and largest shareholder Hansjörg Wyss to Johnson & Johnson for $19.7 billion in cash and stock. It is now part of their DePuy franchise.