Healing assessment of an internally fixated femur using vibration analysis

The lack of a quantitative method to adequately assess fractured bone healing that has undergone fixation limits prognostic capabilities on patients' optimal return to work. This paper addresses vibrational analysis - used to monitor the state of healing of a plate-screw fixated femur to supplement the current clinical radiographic assessment. This experimental study involves an osteotomized, composite femur specimen with modelling clay added to simulate the damping effect of overlying soft tissues. Epoxy adhesive was applied to the fractured region and allowed to cure to simulate the healing process. With the instrumentation described, the cross-spectrum and coherence were obtained and analyzed in the frequency domain over a period of time. The results suggest that it is crucial to analyze the cross-spectrum and proposed healing index to quantitatively assess the stages of healing. The results also show that the mass loading effect due to modelling clay did not influence the described healing assessment technique. The findings indicated a potential, non-intrusive technique to evaluate the healing of fractured femur by measuring the vibrational response.