Quasi-Continuous Autodriven System With Multiple Rates for Distraction Osteogenesis

Introduction. For a given rate of distraction a greater frequency of distraction improves bone formation. However, the current distractors used in clinic are activated manually and produces intermittent advancement. Method. The authors developed an automatic driver that is capable of producing quasi-continuous distraction at a set of rates of 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 mm/d. Using a customized in vitro experimental system, the function and stability of the autodriven system were tested during loading. Results. The angular displacement of the automatic driver was quite regular while driving a constant torque of 4.268 x 10(-3) kg m. The driving achieved the target speed with the constant torque. Conclusions. The automatic driven system provides a useful tool to assess the tissue healing at variable distraction rates with quasi-continuous traction. It demonstrates a potential for clinical application to shorten the treatment course of distraction osteogenesis.