EARLY DETECTION OF DELAYED UNION IN LOWER LEG FRACTURES USING A COMPUTERIZED ANALYSIS OF MECHANICAL VIBRATION REACTIONS OF BONE FOR ASSESSING THE STATE OF FRACTURE-HEALING

Standard X-ray techniques are used to follow up the healing process of bone fractures. However, these methods allow only indirect conclusion s about the stability of the healing bone, depending on the experience of the clinician. In addition, by radiologic means, delayed union or non-union can only be diagnosed on the basis of the absence of specifi c changes such as callus formation. Therefore, efforts have been made to develop alternative methods for monitoring the healing process. The measuring principle of a non-invasive method is based on evaluation o f changes in mechanical vibration reactions. The measuring system is c omposed of two sound transducers, an amplifier module and an AD conver ter attached to a PC. The assessment of 150 healthy individuals as wel l as an initial measuring series after treatment of tibial fractures w ith an external fixator system revealed highly significant differences between intact and fractured tibias. Thus, computerised sonometry is capable of supplying quantitatively recordable information about the s tability of a fractured bone at any time in the healing process. Furth ermore, this non-invasive technique allows early diagnosis of disorder s in the repair process by the absence of change in the parameters.