He earned his medical degree at UT Southwestern Medical Center and completed his orthopedic surgery residency at Parkland Memorial Hospital and his fellowship in pediatric orthopedic surgery at Rady Children's Hospital in San Diego. Dr. Rathjen is a member of the Pediatric Orthopedic Society of North America, the Scoliosis Research Society, the American Academy of Cerebral Palsy and Developmental Medicine, the American Academy of Orthopedic Surgeons, and the American Medical Association.