Dr. Mark Theiss is a specialty care physician board certified in orthopaedic surgery and sports medicine. Dr. Theiss joins Inova Medical Group with over 30 years of clinical experience. He has a special interest in shoulder, knee, and hip replacement coupled with a passion for sports medicine.  For the past 13 years to present, Dr. Theiss has served as a chairman of the Department of Orthopaedics at Inova Fairfax Hospital. He is also a clinical associate professor with the Department of Orthopaedic Surgery at Georgetown University Medical Center and at the VCU School of Medicine Inova Campus.