The Vanguard XP Bicruciate Knee Replacement is a new design from Zimmer Biomet. It is currently performed in 6 centres in the UK and the first European implantation was performed by Hugh Chissell in Nov 2013 at Frimley Park.
Currently all total knee replacements on the market remove at least the anterior cruciate ligament which is still present in 75% of knees needing a knee replacement. Currently the best functional results after joint replacement are from partial knee replacements such as the Oxford unicompartmental knee replacement which leave both cruciates intact. The intact ligaments provide stability to the knee and also have stretch receptors in them that provide feedback of the knee position. This is called proprioception and generally the better the proprioception in a knee the better the function.
The Vanguard XP is for knees too badly worn for a partial knee but with an intact anterior cruciate. It aims to get better function due to improved proprioception than a normal total knee replacement. This is achieved by redesigning the tray that fits on top of the tibia to leave the central part of bone where the anterior and posterior cruciate ligaments attach. The surgery is more complex than an ordinary knee replacement and takes a little longer. Post operatively patients seem to mobilise more like a partial knee replacement than a total knee replacement achieving good function earlier.
Currently a multi centre trial of the Vanguard XP is being set up at the six centres where it is currently being performed. This is called the ALLIKAT trial and should give data to show if the results are better than a standard knee replacement.
Author – Hugh Chissell
Tel: 01252 851200