Washington Health Sets World Record: 1,000 Robotic Knee Replacements Performed With Next Generation Handheld Robotics and Advanced Implants

Fremont, Calif. (April 21, 2026) – Washington Health, a regional leader in innovative community health care in the San Francisco Bay Area, has reached a historic milestone of 1,000 robotic-assisted knee replacements performed using a handheld TMINI^® Miniature Robotic System from THINK Surgical, Inc. for precision implants like the Persona^® Personalized Knee System from Zimmer Biomet, enabling a more personalized, highly accurate surgical approach.

The procedures were performed by renowned orthopedic surgeon Alexander Sah, M.D., medical co-director of the Institute for Joint Restoration & Research and medical director of the Outpatient Arthroplasty Program at Washington Outpatient Surgery Center, with the support of Washington Health’s orthopedic care team. Dr. Sah was selected in 2024 by THINK Surgical, an innovator in orthopedic surgical robotics, and global medical technology leader Zimmer Biomet to be the first surgeon to perform this groundbreaking procedure.

“Miniature handheld robotic technology is transforming knee replacement surgery with a level of precision, accuracy, and consistency not previously seen,” said Dr. Sah. “This technology allows precise implant sizing and placement based on preoperative 3D modeling and intraoperative soft-tissue balance measurements resulting in a uniquely personalized knee surgery for each individual patient. As a Fremont native born at Washington Health, where my father served as a surgeon for more than 40 years, I’m honored to continue his legacy of surgical innovation and personalized care in our community and beyond.”

East Bay resident Thelda King, a lifelong advocate for staying active, became the 1,000th patient to undergo TMINI robotic-assisted knee replacement – a milestone she said came as a complete surprise, having also been the program’s 100th patient. In her late 70s, after years of conservative treatments and increasing instability, she underwent surgery. Now 80 and recovering from a second knee replacement on her other knee, King reports minimal pain and improving mobility, with both knees replaced and plans to return to dancing, traveling, and volunteering.

“Dr. Sah and Washington Health have shown what’s possible when a highly skilled surgeon is equipped with the right technologies,” said Kevin Thornal, Group President of Global Businesses and the Americas for Zimmer Biomet. “This milestone reflects the power of combining surgical judgment and experience with robotic precision and high-quality implants designed for a more personalized fit. It’s not only the robot, and it’s not only the implant – it’s how a surgeon brings both together to drive patient outcomes.”

The milestone highlights the rapid advancement of robotic technology in joint replacement surgery. By pairing robotic precision with implants designed to match each patient’s anatomy, two key challenges in knee replacement surgeries are addressed: accurate placement and individualized fit. Utilizing a CT scan of each patient’s knee, the TMINI system develops a 3D model to ensure exact alignment and implant size. Second, the intraoperative real-time evaluation of muscle, tendon, and ligament tension allows knee component placement based on the individual’s soft tissue envelope ensuring a customized surgery. The integration of this technology is setting a new standard in orthopedic care.

“Developing orthopedic robotics right here in Fremont, in close proximity to Washington Health, creates a unique opportunity for collaboration between surgeons and engineers,” said Chris Marrus, Executive Vice President of THINK Surgical. “Our partnership and proximity helps accelerate innovation and ensures patients in the community benefit from the latest advancements in surgical care.”

Being the site performing the most procedures in the world, Washington Health’s Institute for Joint Restoration & Research serves as a teaching center for the THINK Surgical platform, providing training for surgeons globally. As surgeons train with Dr. Sah at Washington Health and return to their own hospitals, the expertise developed in Fremont is helping expand access to robotic-assisted knee replacement surgeries for patients across the country and around the world.

“We’re proud of Dr. Sah and his team at Washington Health for providing our community with orthopedic surgical technologies that are improving lives,” said Kimberly Hartz, CEO of Washington Health. “Reaching 1,000 procedures marks a historic milestone for our hospital and reflects our commitment to delivering more precise, personalized care, faster recovery, and better long-term outcomes for every patient we serve in our community.”

Today’s announcement comes on the heels of Washington Health earning top national recognition for patient safety and orthopedic care. The hospital is the only Bay Area facility to receive both the Outpatient Joint Replacement and Outpatient Orthopedic Surgery Excellence Awards from Healthgrades, placing it among the top 5% of hospitals nationwide. In addition, Washington Health earned the Healthgrades Patient Safety Excellence Award. Dr. Sah was also recently recognized by Newsweek as the No. 2 knee surgeon and No. 21 hip surgeon in the U.S., further underscoring Washington Health’s leadership in delivering high-quality, innovative care.

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About Washington Health

Washington Health is an independent, community-based health system governed by the publicly elected Washington Township Health Care District Board. Opened in 1958, Washington Health has grown to include a 415-bed, acute care hospital that includes the Morris Hyman Critical Care Pavilion that also houses emergency services and a level II trauma center; the Bell Neuroscience Institute of Silicon Valley; the Institute for Joint Restoration and Research; Peninsula Surgery Center; Washington Outpatient Surgery Center; Washington Outpatient Rehabilitation Center; Washington Health Medical Group; Washington Health Urgent Care, and Washington West that houses the UCSF-Washington Cancer Center, Washington Women’s Center, Outpatient Imaging Center, and additional outpatient hospital services and administrative facilities. Through the Washington Health Foundation, generous donor and community support helps advance innovation, expand access to care, and strengthen vital programs. The health system continues to receive top-tier awards and distinctions for many programs and services, while advancing the level of medical care and treatment in Southern Alameda County. Discover more at washingtonhealth.com, and through Facebook, X (Twitter), LinkedIn and Instagram.

About Alexander Sah, MD

Alexander Sah, MD currently serves as Director of the Outpatient Joint Replacement Program and as Co-Director of the Institute for Joint Restoration and Research at Washington Hospital in Fremont, CA. He was born at Washington Hospital and raised in Fremont. He earned his medical degree, graduating Magna Cum Laude, from Thomas Jefferson Medical College in PA. He then went on to complete his residency at the Harvard Combined Orthopaedic Program and then a joint reconstruction fellowship at Rush University Medical Center in Chicago. Dr. Sah specializes in minimally-invasive outpatient total knee and total hip replacement, and developed the outpatient program in Fremont in 2014. He is a surgeon educator of anterior hip replacement and robotic-assisted knee replacement techniques and technologies. Dr. Sah is a member of leadership committees for the American Academy of Orthopedic Surgeons, the California Orthopedic Association, and the American Association of Hip and Knee Surgeons. In 2016, he was selected as 1 of 10 orthopedic surgeons in the nation to the prestigious AAOS Leadership Fellows Program. Dr. Sah was President of the Anterior Hip Foundation in 2022, published a textbook with Dr. Joel Matta, pioneer of anterior hip replacement, in 2023. He continues to serve on the Board of Directors for the Anterior Hip Foundation and is Director of the AHF Traveling Fellowship. He is second-vice-president of the California Orthopedic Association, and serves on many other hip and knee leadership committees. He is a multi-year recipient of the “Best of Fremont” and "Best of Silicon Valley" Orthopedic Surgeon Awards and San Francisco Magazine Top Doctor awards, named California Top 10 Orthopedic Surgeon, recognized as one of 2020 Becker's "65 Knee Surgeons in Nation to Know", among many other honors. He also serves as a reviewer for Clinical Orthopedics and Related Research and an editor for Techniques in Orthopaedics. Dr. Sah is widely published and is an esteemed speaker, having presented at more than 50 meetings and conventions across the United States.

About THINK Surgical, Inc.

THINK Surgical, Inc., is a privately held U.S.-based technology innovator that develops and markets orthopedic robots. THINK Surgical robots are open platforms providing support for implant brands from multiple manufacturers, enabling the choice of implant to be driven by the surgeon.

THINK Surgical actively collaborates with health care professionals around the globe to refine our orthopedic products, improving the lives of those suffering from advanced joint disease with precise, accurate, and intelligent technology. 

Please refer to the instructions for use for the TMINI Miniature Robotic System for a complete list of indications, contraindications, warnings, and precautions. For additional product information, please visit www.thinksurgical.com.

THINK Surgical and TMINIare trademarks of THINK Surgical, Inc.

About Zimmer Biomet

Zimmer Biomet is a global medical technology leader with a comprehensive portfolio designed to maximize mobility and improve health. We seamlessly transform the patient experience through our innovative products and suite of integrated digital and robotic technologies that leverage data, data analytics and artificial intelligence.

With 90+ years of trusted leadership and proven expertise, Zimmer Biomet is positioned to deliver the highest quality solutions to patients and providers. Our legacy continues to come to life today through our progressive culture of evolution and innovation.

For more information about our product portfolio, our operations in 25+ countries and sales in 100+ countries or about joining our team, visit www.zimmerbiomet.com or follow on LinkedIn at www.linkedin.com/company/zimmerbiomet or X / Twitter at www.twitter.com/zimmerbiomet.