Denis McLean Riddell was born on 2 June 1927 in the UK. He studied medicine at London University and Guy’s Hospital, qualifying in 1950. For his National Service he served in Malaysia from 1952 to 1954 with the 21st field surgical team of the RAMC. He passed the fellowship of the college in 1956 and undertook further training in orthopaedic surgery while working at the Royal National Orthopaedic Hospital in London and the Robert Jones and Agnes Hunt Orthopaedic Hospital in Oswestry, Wales, qualifying in 1964. After working for a while as a senior registrar in the orthopaedic department of the London Hospital, he emigrated to Canada in 1965, settling in Winnipeg, Manitoba. He established a private practice in Winnipeg and also became an assistant professor in the faculty of medicine at Manitoba University. Other work included the role of consultant to the Porterage School for the Disabled at Porterage la Prairie and to the Manitoba chapter of the Canadian Haemophiliac Society. From 1972 to 1976 he was chief of staff at the Shriners Hospital for Crippled Children in Winnipeg and in1977 moved to Kamloops, British Columbia, where he continued private practice and also worked as chief of staff and president of medical staff at the Royal Inland Hospital. In 1992 he retired and moved to Vancouver, meanwhile volunteering for a month every year at a clinic for amputees in the Caribbean island of Nevis. In 1974 he became a fellow of the British Orthopaedic Association and from 1975 to 1977 he served as president of the Winnipeg Orthopaedic Society. He was also a fellow of the Royal Society of Medicine. A keen sportsman, he excelled on the rugby pitch and race track, boasting that he had once raced with Roger Bannister. In Vancouver he enjoyed sailing a Klepper boat on Lake Shuswap and cycling round Stanley Park. He had married Mollie in 1955 and was a devoted husband. Sadly she developed Alzheimer’s and he was, for a while, her principal carer. When he died on 4 May 2015 aged 87, he was survived by Mollie, their children, Fiona, Alastair, Duncan and Euan and five grandchildren.