Development of a Total Knee Replacement

Institution:

SUNY Upstate Medical University

Researchers:

David G Murray, MD, Department of Orthopedics, Upstate Medical University; James Albert Shaw, Department of Orthopedics, Upstate Medical University; J.H. Somerset, Department of Orthopedics, Upstate Medical University.

Impact:

Many early total knee replacements experienced gross loosening of the components in part due to being implanted without rigorous laboratory testing.  David Murray, MD came up with a new knee replacement design while on a trip to Mexico, which was in part based on the ball and socket joint of the hip. This was the first knee replacement design that included a tibial component consisting of a metal tray and stem with removable plastic (polyethelene) inserts. Current knee designs include many of its unique features.

Timeline:

Work begin in 1972 when Dr. Murray started a research project between the Department of Orthopedic Surgery and the Department of Mechanical Engineering at Syracuse University to develop and test this new knee replacement design. Prototype implants were created, using the curvature of the inside of a tennis ball and these designs were tested for millions of cycles in a mechanical knee simulator. Only after additional successful testing was performed was the new design finalized and implanted into patients. The clinical success of the Variable Axis Knee was a remarkable improvement upon other early knee replacements. Current knee designs include many of its unique features.