Appointed to Toronto's Hospital for Sick Children and the University of Toronto in 1955, Salter became chief of orthopedic surgery in 1957 and surgeon in chief in 1966. In 1976, he was appointed head of orthopedics at the University of Toronto. In the late 1970s he originated the revolutionary concept of continuous passive motion (CPM) of joints to stimulate the regeneration of cartilage. Following his retirement, he was senior orthopedic surgeon emeritus and senior scientist emeritus at the Research Institute of the Hospital for Sick Children.

Salter wrote over 150 scientific articles and a textbook on the musculoskeletal system, Disorders and Injuries of the Musculoskeletal System. His honours included fellowship of the Royal Society of Canada, the Nicolas Andry Award and the Gairdner Foundation International Award for Medical Science. In 1995 he was inducted into the Canadian Medical Association (CMA) Hall of Fame and in 1997 he became the 32nd recipient of the CMA's F.N.G. Starr Award. He was a Companion of the Order of Canada.