Our Doctors

Bradley L. Baum, M.D.

Bradley L. Baum, M.D. joined Corona Orthopaedic Associates in April of 1989. He received his medical degree at Loma Linda University Medical School and completed his post graduate work at Loma Linda University Medical Center and Riverside General Hospital. Dr. Baum also completed a Fellowship in Foot & Ankle surgery at The University of Washington, Harbor University Medical Center. He was certified by the American Board of Orthopaedic Surgeons in 1994 and is a member of the American Academy of Orthopaedic Surgeons since 1996. Dr. Baum has a special interest in all orthopaedic sports injuries including shoulders, knees and ankles.


Ghassan S. Tooma, M.D.

Ghassan S. Tooma, M.D. joined Corona Orthopaedic Associates in April of 1994. He received his medical degree at Loma Linda University and completed his post graduate work in Orthopedic Surgery at Loma Linda University Medical Center. Dr. Tooma completed a Fellowship in total joint replacement at the University of Iowa and a Fellowship in hand surgery at Loma Linda University Medical Center. Dr. Tooma has a special interest in total joint replacement including Robotic Assisted Joint Replacement, hand and arthoscopic surgery.


John S. Locke , M.D.

John S. Locke, M.D. joined CTOA in November of 2012 after completing 20 years in military medicine with the United States Navy. He received his medical degree at the Uniformed Services University in Bethesda, Maryland. He completed his orthopaedic surgery residency at Stanford University. Dr. Locke became board certified by the American Board of Orthopaedic Surgery in 2001 and went on to complete a fellowship in arthroscopy and sports medicine at UC San Diego in 2005. He then completed the requirements for sub-specialty certification in sports medicine. He has a special interest in minimally invasive techniques and accelerated rehabilitation to help patients get back to their activities quickly. Dr. Locke’s career in the Navy took him to hospitals in Virginia, Hawaii and Japan as well as Twentynine Palms and Camp Pendleton, California. A native of California, when not working, he enjoys spending time with his family and being involved in the local community and schools.


Nasser Heyrani, M.D.

Nasser Heyrani, M.D., joined Corona Temecula Orthopaedic Associates in October 2020. He is a fellowship-trained orthopaedic surgeon in foot and ankle reconstructive surgery.

He received his undergraduate and medical degrees at the University of California, Los Angeles (U.C.L.A.), and completed his residency at University of California, Davis (U.C. Davis), where he spent an additional year researching stem cell therapies for bone regeneration. Dr. Heyrani continued with a subspecialty fellowship in foot & ankle reconstructive surgery at the prestigious Harvard-Massachusetts General Hospital in Boston, Massachusetts, under the mentorship of internationally renowned foot & ankle surgeon, Dr. Christopher DiGiovanni.

Dr. Heyrani sees patients for a variety of orthopaedic, foot and ankle injuries, deformities, and surgeries. Whether it is an athlete trying to return to the soccer field, or those suffering from chronic arthritis, Dr. Heyrani’s goal is to improve a patient’s quality of life by delivering compassionate, safe, and effective care centered around an individual’s needs.

During his time at Harvard-Massachusetts General Hospital, Dr. Heyrani served as a team physician providing sideline coverage for Major League Soccer’s New England Revolution. Dr. Heyrani enjoys consulting with recreational, collegiate, and professional athletes, and has a special interest in the management of all sporting injuries of the foot and ankle.

Dr. Heyrani has many interests including soccer, tennis, and traveling abroad.

More information regarding Dr. Heyrani can be found at: TheSoccerMD.com


Eli T. Sayegh, M.D.

Dr. Eli Sayegh is a Harvard-trained sports medicine orthopaedic surgeon who joined Corona-Temecula Orthopaedic Associates in September 2021. He offers the highest level of individualized musculoskeletal care for a wide range of bone, joint, muscle, tendon, ligament, and sports-related injuries of the shoulder and knee. Dr. Sayegh is a fellowship-trained specialist in minimally invasive, arthroscopic surgery as well as shoulder replacement and joint preservation. He strives to alleviate pain and improve function without surgery whenever possible, and employs state-of-the-art techniques to get his patients back to their activities.

Dr. Sayegh obtained his medical degree at Columbia University College of Physicians and Surgeons, in New York, NY. He completed his orthopaedic surgery residency at the State University of New York, in Brooklyn, NY. He then completed subspecialty training in sports medicine at the prestigious Harvard–Brigham and Women’s Hospital fellowship program, in Boston, MA. While in Boston, he served as an assistant team physician for the Boston College football team at the Division I level.

Dr. Sayegh has been extensively involved in scientific research, including a Howard Hughes Medical Institute (HHMI) Medical Research Fellowship. He has published over 40 peer-reviewed scientific articles in journals including the Journal of the American Academy of Orthopaedic Surgeons, Clinical Orthopaedics and Related Research, Journal of Shoulder and Elbow Surgery, and Arthroscopy, while serving as a reviewer for the Journal of the American Academy of Orthopaedic Surgeons and Arthroscopy.

A native of Southern California, Dr. Sayegh keeps active with running, biking, tennis, and soccer, and enjoys playing piano, spending time with his family, and exploring all that Southern California has to offer.

Meet our Physician Assistants

Contact Our Office

Corona Office

341 Magnolia Ave, Suite 101
Corona, CA 92879
(951) 735.6060

Murrieta Office

28078 Baxter Rd, Suite 330 / 340
Murrieta, CA 92563
(951) 677.2157