Dr. David G. Lewallen is a Professor of Orthopedic Surgery and Consultant in the Department of Orthopedic Surgery at Mayo Clinic in Rochester, Minn. He is a graduate of Gustavus Adolphus College, received his MD degree from the University of Minnesota, and completed a residency and Master's degree program in research in the Department of Orthopedic Surgery at Mayo Clinic. He then completed a fellowship in Biomechanics research at Beth Israel Hospital in Boston before returning to join the consulting staff at Mayo Clinic. Dr. Lewallen's initial practice was focused on lower extremity problems including both arthroplasty and trauma-related care, especially of the hip and pelvis. He has had a career-long involvement with the Mayo Clinic Total Joint Registry, which has prospectively collected data on all of the over 100,000 joint arthroplasties performed there. He has been active in numerous professional societies and their boards, and is the past president of the American Association of Hip and Knee Surgeons, The Hip Society, the Association of Bone and Joint Surgeons, and the Mid-America Orthopaedic Association. He was heavily involved in the more than decade-long development of the American Joint Replacement Registry and served for three years as the first Chair of the Board of Directors after it was incorporated in 2009. In 2013, he transitioned to Medical Director for the AJRR and continues to assist in efforts to establish a nationwide registry of arthroplasty procedures. Dr. Lewallen's current clinical practice and research activities are focused on hip and knee arthroplasty, revision surgery, clinical applications of highly porous metal materials, and the management of arthroplasty complications.