Maurice Edmond Müller was an eminent Swiss orthopaedic surgeon who developed internal fixation techniques to treat bone fractures and designed new hip protheses. He was born in Biel, Switzerland, and studied medicine at the universities of Neuchâtel, Berne and Lausanne. He gained his MD from the University of Lausanne in 1944. From 1944 to 1946 he was a resident in orthopaedics at the Clinic Balgrist, Zürich. In 1947 he went to Jimma in Ethiopia, where he worked at the Hospital for Tropical Surgery. The next year, he returned to Switzerland, and held training posts in general surgery at Liestal and Fribourg. From 1952 to 1957 he was chief resident in orthopaedic surgery at the Clinic Balgrist in Zürich. In 1960 he was appointed director of the clinic for orthopaedics and traumatology at the Kantonsspital, St Gallen, a post he held until 1967. From 1963 to 1980 he was professor of orthopaedic surgery at the University of Berne, and chairman and director of the department of orthopaedic surgery, Inselspital, Berne. He pioneered the development of a standardised set of implants and surgical instruments for the fixation of fractured bones. In 1958, with Martin Allgöwer, Hans Wilenegger, Robert Schneider and Walter Bandi, he founded Arbeitsgemeinschaft für Osteosynthesefragen (AO) - the Association for the Study of Internal Fixation. He was also renowned for his joint replacement work. In 1965 he started Protek AG, which manufactured and distributed the protheses and surgical instruments he designed for the replacement of osteoarthritic or misshapen hip joints. From 1974 all profits went to the Fondation Maurice E Müller, which Müller set up to advance education and research in orthopaedic surgery. He received numerous awards for his work, including being made an honorary citizen of Berne. He became an honorary fellow of the Royal College of Surgeons in 1982. In Berne, he helped establish the Zentrum Paul Klee, a museum dedicated to the work of the Swiss artist. He was married to Marty. They had three children, Jean Pierre, Janine and Denise. Maurice Müller died on 10 May 2009 in Berne, aged 91.