Electrical conductance as the predictor of fracture healing

Introduction Measurement of electrical conductance can be a useful tool for early diagnosis of delayed and non-union of fractured bone. Their role and relationship with the frequency of supplied alternating current has been studied here for the measurement of fracture healing. Materials and methods About 12 patients, between 18 and 50 years of age with compound fractures of bones in both legs (Gustillo’s grade I and II), treatable by external fixators, without associated injuries or complications, reporting to the trauma centre of KGMU Lucknow, Uttar Pradesh, India, were treated by insulated external fixators. Electrical conductance was measured within 24 hours after the surgery and then on two weekly intervals for 10 weeks by an LCR-Q (inductance, capacitance, resistance-quality) meter on frequency of 100 Hz and 1 KHz, which also permitted measurement of conductance. The patients were then classified into ‘union at week 20’ and ‘non-union at week 20’, based on clinic–radiological assessment by three blinded clinicians. The two concordant decisions were considered as the best decision. Results Patients with delayed union had lower conductance than patients with normal union. Electrical conductance was able to demarcate ‘union at week 20’ from ‘non-union at week 20’ significantly at week 10 at frequency of 1 KHz (p = 0.009 at week 10) and insignificantly at (p = 0.16). Conclusion However, electrical conductance is highly influenced by change in frequency due to differential dissipation of bound water; it may be a useful tool for the early diagnosis of delayed union and non-union at frequency of 1 KHz.