Mark Knable Mark Knable, D.O., earned his Medical De­gree from Ohio University College of Osteopathic Medicine, in Athens, Ohio. He completed his internship and residency in orthopedic sur­gery at Brentwood Hospital, in Warrensville Heights, Ohio. Dr. Knable was previously an assistant professor of orthopedic surgery at Ohio University, in Athens. He has been practicing orthopedic surgery for more than 20 years and is board certified in orthopedic surgery.