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Mark M. Theiss, MD

Inova Medical Group

Board Certified Specialty: Orthopaedic Sports Medicine, Orthopaedic Surgery

Clinical Interest: Hip Replacement, Knee Problems/Surgery and Treatments, Knee Replacement, Shoulder Problems/Surgery and Treatments

Accepting new patients for: Orthopaedic Sports Medicine

Gender: Male

Languages: English

Physician Group

Inova Medical Group - Orthopaedics and Sports Medicine II

Hospital Affiliations


Dr. Mark Theiss is a specialty care physician board certified in orthopedic 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 for the Department of Orthopedic Surgery at Inova Fairfax Hospital. He is also a Clinical Associate Professor with the Department of Orthopedic Surgery at Georgetown University Medical Center and at the VCU School of Medicine at the Inova Campus.

Dr. Theiss became interested in orthopedic surgery when participating in sports during his youth. After witnessing sports injuries, he took a keen interest in the medical process and helping his teammates recover so they could return to sports. That passion continues today. He enjoys assisting patients of all ages with the return to an active lifestyle, regardless of athletic ability or age.

Dr. Theiss grew up in San Francisco and currently resides in Fairfax, VA with his wife who he coaches during marathon and duathlon training. He is an avid distance cyclist, skier and fisherman.


Medical Education:

  • Georgetown University School of Medicine 1975

Board Certification:

  • Orthopaedic Sports Medicine
  • Orthopaedic Surgery


  • Georgetown University School of Medicine Orthopaedic Surgery 7/1/1976-6/30/1980


  • St. Barnabas Medical Ctr. General Surgery 7/1/1975-6/30/1976

Areas of Interest

  • Hip Replacement
  • Knee Problems/Surgery and Treatments
  • Knee Replacement
  • Shoulder Problems/Surgery and Treatments
Disclosure Statement for Online Physician Referral Service

Thank you for accessing the Inova Physician Referral Service. Please make note of the following information.

This referral service is sponsored by Inova. Only physicians with appropriate medical staff privileges at an Inova affiliated hospital may participate. There is no charge or fee to you or for the participating physician for our service. Physician participation is voluntary.

Physician referrals will be based on your referral needs and preferences of location, specialty, and rotation availability of the physician.

The physicians on our referral panel are independent practitioners or physician employees. The independent practitioners are not employees, agents or representatives of Inova and are solely responsible for their provision of medical care to you.