Orthopedic Surgeon Mark Klaassen learned early on what caring for others is all about. The son of missionaries, he grew up in Colombia where the positive impact of helping others was tightly woven into his character. This childhood experience made him fluent in Spanish. He returned home to the U.S. as a 15-year-old to continue his education, culminating in the MD degree he earned from the Indiana University School of Medicine at Notre Dame and the I.U. Medical Center. He completed his orthopedic surgery residency at Lutheran Hospital of Indiana and is a Fellow of the American College of Surgeons and the American Academy of Orthopaedic Surgeons. Dr. Klaassen is an active member of the American Association of Hip and Knee Surgeons.

Throughout his career he has been a mentor to other orthopedic surgeons throughout the U.S. and other countries, providing instruction on advanced orthopedic surgical techniques and procedures – many of which he was instrumental in developing. For example, Dr. Klaassen was a pioneer in advancing the use of the patient’s own autologous platelets to energize the healing process and accelerate recovery following joint replacement surgery.

Dr. Klaassen’s areas of specialized expertise include knee, hip and shoulder total joint replacement, and arthroscopic surgery. He currently serves as Professor of Practice in the College of Sciences at the University of Notre Dame. Dr. Klaassen is a consultant and Developer for Biomet, OrthoSensor and Iconacy.


Dr. Klaassen is a fellow of the American College of Surgeons (FACS) and the American Academy of Orthopaedic Surgeons (FAAOS). He is also an active member of numerous medical organizations, including the American Association of Hip and Knee Surgeons (AAHKS), American Medical Association (AMA), Mennonite Medical Association (MMA), American Orthopaedic Foot & Ankle Society (AOFAS), American Fracture Association (AFA), and the Indiana Orthopaedic Society.