Saint Francis Orthopedic Institute Surgical Team

Orthopedic surgeons at the Saint Francis Orthopedic Institute are experts in the field of orthopedic and joint replacement and spine surgery.

Saint Francis Orthopedic Institute  Surgeons – Joint Replacement Specialists

Orthopedic surgeons at the Saint Francis Orthopedic Institute are experts in the field of orthopedic and joint replacement surgery. They are comprised of the orthopedic medical directors and spine specialists. Saint Francis orthopedic surgeons deliver top-quality joint care, including some of the latest surgical techniques such as anterior approach hip replacement surgery and robotic-assisted partial knee replacement surgery. 

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Nicholas Mast, MD,  Medical Director,   Saint Francis Orthopedic Institute, is a board certified in orthopedic surgery. He specializes in anterior approach total hip replacement surgery, a procedure that involves making a small incision at the front of the hip, rather than in back. With this technique, patients find their mobility is restored sooner and their recovery time is shorter than with traditional hip replacement surgeries. To learn more about Dr. Mast, visit his website at


Robert Purchase , MD,  Medical Director of Shoulder Surgery, is a board-certified, fellowship trained orthopedic surgeon.  Widely recognized as an expert in complex and revision shoulder arthroplasty, patients travel from all over California to have their shoulder replacement surgery done by Dr. Purchase. He treats all manner of shoulder disease from arthroscopic repair of rotator cuff tears, to revision reverse total shoulder replacements. To learn more about Dr. Purchase, visit his website at


Victor Prieto, MD, is physician member of the Saint Francis Orthopedic Institute and the  Medical Director for the Center for Sports Medicine at Saint Francis Memorial Hospital. He specializes in hip and knee replacements, and shoulder surgery. His expertise includes mini-incision hip replacement, Mumford procedure, knee arthroscopy, uni-compartment and robotic-assisted knee replacement, and computer-navigated joint replacement.

Saint Francis Orthopedic Institute Surgeons - Spine & Neck Specialists

Spine surgeons focus on the most advanced technologies to treat back pain and spine and neck conditions. Our board certified orthopedic spine surgeon is committed to providing the finest personalized care for all spinal conditions. You can be confident that you will receive top-quality surgical care.


Brian W. Su, MD is a board certified spine surgeon. He received his undergraduate education from Duke University’s School of Engineering and his medical degree from Columbia University’s College of Physicians and Surgeons. He completed an orthopedic and neurosurgical spine surgery fellowship at the Rothman Institute, Thomas Jefferson University Hospital in Philadelphia. Dr. Su educates his patients so they fully understand their disease and treatment options, emphasizing non-operative treatment, reserving surgery as the last option. When surgery is necessary, he seeks the least invasive option. 

Learn More About The Saint Francis Orthopedic Institute

For more information or to schedule an appointment, please call (415) 353-6380 or email [email protected] or request an appointment online today.