
Mr Marston studied medicine at St Thomas’ Hospital, London University from 1979, qualifying MBBS in 1985. In 1982 he gained BSc. Honours in Anatomy, and was 1 of 10 students to win an intercalated degree place.
After house jobs at St Thomas’ and St Peter's Chertsey, he was a full time lecturer in Anatomy, at St Mary's Paddington, for a year whilst studying for the primary Surgical Fellowship. After A&E at St Mary's, he spent two and a half years at the United Norwich Hospital group as a basic surgical trainee. This culminated in gaining the final fellowship of both the Royal College of Surgeons of England and Edinburgh.
In 1990, he was appointed to the Royal National Orthopaedic Hospital / Middlesex Hospital Orthopaedic Training Scheme. During his training, he spent six months as Johnson and Johnson research fellow for Professor Bentley. He was Zimmer Fellow to Mr William Muirhead-Allwood.
In March 1995 he gained the Orthopaedic Specialist Fellowship. At the end of his training he won a British Orthopaedic Association Fellowship spent in three centres in the USA and Australia.
He was appointed Consultant Orthopaedic Surgeon to St Mary's Hospital / Imperial in October 1995 with a special interest in hip, revision hip and knee replacement surgery. He also performs lower limb trauma surgery.
After 20 years, the last seven as head of N.W Thames Surgical Training, he started a full time private medical and medico legal practice in April 2016 at the Hospital of St John and St Elizabeth. Having been invited to consult at King Edward VII's Hospital, he relocated his practice in October 2020 and is now based solely at King Edward VII's Hospital, London W1.