Study Shows Significant Advantages of Computer-Assisted Robotic Total Knee Replacement

A study of 1,000 consecutive Computer-Assisted Robotic Total Knee Replacements performed over a five year period at Mercy Medical Center in Rockville Centre, NY demonstrates that the computer-assisted procedures result in far better leg alignment, much less likelihood of complicating infection, and a far lower early failure rate than surgeries performed using conventional techniques.
The key factor in successful total knee replacement is precise placement of the artificial joint so that the center of the patient’s hip and knee lines up within three degrees of the patient’s ankle. Using conventional techniques, the best surgeons achieve alignment within three degrees 50 to 80 percent of the time. At Mercy Medical Center, alignment within three degrees was achieved in all (100%) of the 1,000 computer-assisted robotic procedures performed between February, 2005 and January, 2010. Final post-surgical alignment averaged just under one degree (0.8).



Typically, the failure rate for knee replacements is three to eight percent per year, and one half of early knee replacement failures, those occurring less than two years after surgery, are attributed to misalignment, instability and aseptic loosening. These typically require a second more difficult and often less successful operation called a revision total knee replacement.
At Mercy Medical Center, there were no early failures and no revision operations secondary to misalignment, instability or aseptic loosening in the first 1,000 consecutive computer-assisted robotic total knee replacement patients over the first five years of the study.
Jan Koenig, MD, Director of Orthopedic Surgery at Mercy Medical Center, presented the findings on March 10, 2010 to a group of over 200 international orthopedic surgeons at the Annual Meeting of the American Academy of Orthopaedic Surgeons (AAOS) in New Orleans. His presentation, The Evolution of Computer-Assisted Total Knee Replacement (CAS-TKR) Past, Present and Future, was a featured part of Medacta Orthopedics Scientific presentations.
It is estimated that as many as 500,000 total knee replacement surgeries currently are performed in the United States each year, with that number projected to increase to more than 4 million annually as the population ages.