Early detection of delayed union in lower leg fractures using a computerised analysis of mechanical vibration reactions of bone for assessing the state of fracture healing

Abstract

Standard X-ray techniques are used to follow up the healing process of bone fractures. However, these methods allow only indirect conclusions 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 specific 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 of changes in mechanical vibration reactions. The measuring system is composed of two sound transducers, an amplifier module and an AD converter attached to a PC. The assessment of 150 healthy individuals as well as an initial measuring series after treatment of tibial fractures with 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 stability of a fractured bone at any time in the healing process. Furthermore, this non-invasive technique allows early diagnosis of disorders in the repair process by the absence of change in the parameters.