our program

Our Providers


James Boyd, MD, Orthopedic Surgery

Dr. Boyd is a board-certified orthopedic surgeon. He completed fellowship training in sports medicine with Scripps Health in San Diego where he treated several athletes with the Padres baseball team and Chargers football team as well as many recreational athletes. He takes great satisfaction in caring for professional and recreational athletes of all ages. Dr. Boyd earned his medical degree and completed his orthopedic residency at Loma Linda University School of Medicine. He also served four years in the United States Navy, practicing general orthopedics at the Robert E. Bush Naval Hospital in Twentynine Palms, California. He has been practicing in Sonora since 2011.


Christopher Krpan, DO, Orthopedic Surgery

Dr. Krpan is a board-certified orthopedic surgeon and has been practicing in the Mother Lode since 2004. He graduated from University of California Santa Barbara and earned a Doctor of Osteopathic Medicine degree from Western University Medical School. He completed his residency at Meirdia South Pointe Hospital which is part of the Cleveland Clinic Health System in Cleveland, Ohio. Dr. Krpan specializes in fracture care, total joint replacement surgery, partial knee replacement, sports medicine and other orthopedic issues of the extremities.


Thomas McDonald, MD, Orthopedic Surgery

Dr. McDonald is a board-certified, fellowship-trained orthopedic surgeon and has been providing patient care in Sonora since 2011. He completed a five-year residency in orthopedic surgery at the University of California Davis Medical Center, a level I trauma center. Following his residency, he joined the Department of Orthopedics at Kaiser Permanente in Sacramento, a level II trauma center. Dr. McDonald also has unique training from his fellowship with The Indiana Hand Center in Indianapolis, where his training included diagnosis, surgical treatment, and rehabilitation of injuries and disorders of the entire upper extremity.


John Nelligan, MD, Orthopedic Surgery

Dr. Nelligan earned his medical degree from Rush Medical College in Chicago, Illinois, and completed his residency in orthopedic surgery at Stanford University Medical Center in Palo Alto, California. He then went into private practice, serving at both Stanford University Medical Center and Sequoia Hospital in Redwood City for over 20 years. He also served as medical director and staff surgeon for the total joint program at St. John’s Medical Center in Longview, Washington, before moving to Sonora in 2012. "It is important to offer each patient a full-spectrum of care, which includes non-surgical measures," Dr. Nelligan explains. "We work with each patient to bring him or her functional restoration and pain relief using the least invasive treatment option that is likely to work.”

Adventist Health Sonora also offers renowned spine care, including cutting-edge treatments for a full range of conditions. The Northern California Spine Institute is a region leader in comprehensive care for the spine.

Learn more about our specialized spine care

Adventist Health Sonora

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