First Robotic-Assisted Total Knee Replacement Surgeries in the Region Performed at Phelps

The first robotic-assisted total knee replacement operations to be performed in the Lower Hudson Valley took place recently at Phelps Memorial Hospital Center. The two surgeries were performed by orthopedic surgeon Dr. Jason Hochfelder, who joined the Phelps medical staff in 2015.  Known for being at the leading edge in orthopedics, Phelps orthopedic surgeons excel at performing advanced and complex procedures, from sports injury surgeries to joint replacements. 

The robotic system, called OMNIbotics, enables the surgeon to plan a customized “virtual” operation on a computer prior to actually performing the operation. The OMNIbotics device creates a computerized 3D model of the femur (thigh bone) and the tibia (shinbone) so the surgeon can see what the implants will look like before cutting those two bones. Based on the 3D model, the robot places the cutting guide for the saw in the exact correct location.

In typical total knee replacement surgery, much of the calculation of lining up the cuts is done by feel, says Dr. Hochfelder. If calculations are not perfect, an unbalanced replacement may result. Using the robot guarantees accuracy of the size and positioning of the implants and helps achieve the most important part of the knee replacement – making sure it has full extension, full ability to bend and equal tightness on both sides of the knee. 

“Both surgeries using the robotic device were successful,” said Dr. Hochfelder afterward, “and completed without complications. When I left the operating room, I was confident that my cuts were perfect, the implants were in exactly the right position and that each patient had a stable, well-balanced knee that was in perfect alignment. I’m delighted to be at Phelps, where we can make this advanced surgical technology available to residents of the Lower Hudson Valley.”     
“Knee replacement is still a major operation,” says Dr. Hochfelder, “but use of the robot allows for more accuracy and, hopefully, better results.” Similar recovery times are required.

Phelps’ excellence in performing joint replacements was recognized in July 2015 in the annual hospital rankings published by U.S. News & World Report, which rated Phelps as High Performing for hip and knee replacement.  

For more information about orthopedic services at Phelps, go to or call 914-366-3367.

About Phelps Hospital

Phelps Hospital, part of Northwell Health, is a full-service 238-bed acute care community hospital located in Sleepy Hollow, NY. With more than 1,700 employees and 500 medical staff members representing 60 medical specialties, Phelps offers one of the broadest ranges of community hospital services in Westchester County. Patients benefit from distinguished physicians, many of whom are pioneers in their field, offering the most advanced procedures using the latest technology. Phelps’ primary and specialty care medical group, Phelps Medical Associates, has nearly 20 practices located on the hospital campus and in the surrounding communities.

About Northwell Health
Northwell Health is New York State’s largest health care provider and private employer, with 23 hospitals, about 750 outpatient facilities and more than 13,600 affiliated physicians. We care for over two million people annually in the New York metro area and beyond, thanks to philanthropic support from our communities. Our 68,000 employees – 16,000-plus nurses and 4,000 employed doctors, including members of Northwell Health Physician Partners – are working to change health care for the better. We’re making breakthroughs in medicine at the Feinstein Institutes for Medical Research. We’re training the next generation of medical professionals at the visionary Donald and Barbara Zucker School of Medicine at Hofstra/Northwell and the Hofstra Northwell School of Graduate Nursing and Physician Assistant Studies. For information on our more than 100 medical specialties, visit

Press Contact

Contact:  Margaret Plofchan, Director of Marketing Phelps Hospital