Tibial external fixation, weight bearing, and fracture movement

Axial fracture movement and loading has been measured during weight bearing in 45 patients with tibial diaphyseal fractures treated with unilateral external skeletal fixation. Mean axial fracture displacement reached a maximum of 0.6 mm between seven and 12 weeks postfracture. Very little movement occurred during the first five weeks after fracture. A micromovement module attached to the fixator increased axial movement at the fracture site by 50% during walking. Weight bearing reached 75% of mean body weight by ten weeks after the fracture. Weight bearing was not decreased by any biofeedback mechanism. A randomized prospective clinical study of diaphyseal tibial fractures treated with external fixation showed a significant reduction in time to healing when micromovement was imposed. Controlled fracture site movement can be imposed very early after fixator frame application when mechanical stimulation may be most effective, and the active loading by the patient is least.