Fitbone™ is a surgical procedure to lengthen arms or legs. It is used to correct deformities and injuries and also for cosmetical purposes. The procedure involves cutting the bone in two and implanting a metal telescopic rod; this rod contains a small electric motor and expands lengthwise about one millimetre per day, powered and controlled by radio signals from the outside; the bone grows around the expanding rod. After the full lengthening (maximally 5 centimetres) has been achieved, the bone needs to strengthen and the rod can be removed about two years after the initial surgery.
Developed in Germany by Betz and Butsch, the first successful operations were performed in 1996 and the technique was patented in 1997. Since 2001, the surgery has also been performed in Tan Tock Seng Hospital, Singapore and in
Bumrungrad Hospital , Bangkok.
The more traditional technique to lengthen legs, invented by the Russian physician Ilizarov in 1951, involves the application of extensible outside metal rods to the cut bone. The rods are then slowly lengthened by turning screws. Compared to the Fitbone procedure, this technique is cheaper but involves a higher risk of infection as well as more pain to the patient. Some newer techniques use internal rods like the Fitbone technique, but are mechanically powered with spring devices, giving less control over the extension process.