SCOTTISH patients are benefiting from a new procedure that uses satellite navigation technology to help replace worn-out knees.

SCOTTISH patients are benefiting from a new procedure that uses satellite navigation technology to help replace worn-out knees.

By using the same global positioning system (GPS) technology used to map out vehicle routes, surgeons at the Nuffield Hospital in Glasgow are successfully carrying out cutting-edge knee operations.

During the procedure, known as navigational knee surgery, a number of wireless trackers are placed onto the joint. An optical camera which is directed towards the trackers then sends out an infra-red beam. The trackers pick up the beam and send a number of signals to a computer, which maps out an interactive model for the surgeon. This allows the surgeon to cut away the damaged joint by carefully following the model, which is accurate to within a fraction of a degree.

Jamie Harper, 61, from Bishopbriggs, was recovering in the private Nuffield Hospital yesterday after becoming the first non-trial patient to undergo the new surgery.

Mr Harper was able to walk up and down the hospital corridor aided only by a walking frame, despite having his operation less than 24-hours previously.

Bill Leach, a consultant orthopaedic surgeon, used the technology to create a three-dimensional model of the knee which guided him through the 90-minute surgery.

The main difference between the new technique and routine knee surgery is its unique ability to pin-point the alignment of the knee, rather than relying on educated guessing.

Mr Leach, who is also using the technique as an NHS surgeon at Gartnavel Royal Hospital in Glasgow, said that although it is too early to say what the long-term benefits of navigational knee surgery will be, the hope is that it will ensure that the knee is as close to perfect after surgery.

He said: "With regular surgery, which is not computer aided, we would hope for close to 80%. This new method increases that figure to 95%."

As a private patient with a health insurance package, Mr Harper said the treatment had cost around £9000