He has been involved in the Spine Society of Australia, Australian Orthopaedic Association and Royal Australasian College of Surgeons, as well as a member and advisor on a number of Federal Government and semi-government committees and panels.

Mr Johnson is also the present Chair and Principle Investigator of the Australian Spine Registry.

Mr Johnson obtained his fellowship of the Australasian College of Surgeons in Orthopaedic Surgery in 1986, marking the beginning of his illustrious career. Between 1986 and 1989, Mr. Johnson pursued further training in spinal surgery at prestigious institutions, including Great Ormond Street Hospital for Sick Children and The Royal National Orthopaedic Hospital in London, UK. To expand his expertise, he also completed additional fellowships in Germany and the United States, further solidifying his knowledge and skills in the field.

After returning to Melbourne in 1989, Mr Johnson dedicated his practice exclusively to the specialized field of spinal surgery, particularly the treatment of deformity and degenerative conditions of the thoracic and lumbar spine.