Dr. Longjohn is an assistant professor in the Department of Orthopaedic Surgery at the Keck School of Medicine of USC. He specializes in hip and knee replacement/revision surgery, as well as arthritis, rheumatoid arthritis, osteoarthritis and arthroscopic surgery. In addition to his membership in professional organizations such as American Association of Hip and Knee Surgeons and the Western Orthopaedic Association, Dr. Longjohn is a member of the LA County Sheriff’s Department Medical Reserve Company 206 (Office of Homeland Security) and also volunteers as a flight physician for the LA County Sheriff’s Department Air Rescue 5. Dr. Longjohn has been honored with several teaching awards. His current research focus is on clinical and biomechanical studies relating to joint replacement and arthroplasty revision techniques and materials. Dr. Longjohn did his residency in orthopaedic surgery at USC+LAC and completed a fellowship in arthritis and joint implant surgery at Rancho Los Amigos National Rehabilitation Center/Keck Hospital of USC.