MUSCLE FORCE MEASUREMENT SYSTEM FOR LONG-TERM MONITORING DURING DISTRACTION OSTEOGENESIS

Distraction osteogenesis is a procedure in orthopedics for skeletal lengthening. This operation sometimes causes clinical complications such as paralysis and pain related to the rate and extent of distraction. Therefore, a tension-force monitoring system is mandatory to control optimal lengthening. We developed a portable, low-power consumption system to continuously monitor the distracted tensions during the distraction osteogenesis period on the tibias of four male New Zealand white rabbits. The lengthening rate was 1 mm per day at frequencies of once a day in one rabbit, and of three successive steps in the others. The system indicates the distraction measured by force, which is considered to be more physiological in nature rather than by distance. Radiographs were also taken for comparison. The results showed that the system was stable and approximate to being ideal. The measured distract-tension recovered to a steady state faster at the frequency of 1 mm a day in three steps, rather than once per day. During the duration of the entire operation, each single lengthening induced more extensive force than that of one-day totals. The integer tension gradually increased until 15 days and tended to be stable. The radiographic examinations also revealed that the tibias healed well after the lengthening; consequently, a dispensable X-ray might be mostly replaced by the system monitoring. This system might be helpful to monitor force measurement for the improvement of distraction osteogenesis.