Inductively Coupled Electrical Stimulation - Part 2: Optimization of parameters for orthopedic injuries and pain

Abstract

A commercial research and development feasibility study was conducted using a critical bone gap of 1.0 cm, surgically created in the radial bone of the left forelimb, to determine the viability of PEMF for generating bone to refill the gap in an otherwise non-healing tissue injury site. The full duration of the feasibility study was not completed due to the subsequent financial insolvency of the sponsoring company, however, the critical experiments through week four were sufficiently completed to draw the following conclusions for commercial PEMF technology development purposes: PEMF did generate bone in critical gaps with a success rate of 100% for at least partial bone gap closure, and 40% for full bone gap closure, in the four weeks when PEMF was applied with a slew rate => 100 kG/s. Healing rates of 67% for partial gap closure, but 0% for full gap closure, was observed when PEMF slew rate was half that value, ~ 50 kG/s. Healing in the absence of PEMF was less than 10%, and only for very small amounts of bone gap closure on only one specimen, which may have been due to surgical error. Post-surgical pain was also greatly reduced when higher-slew rate PEMF was applied, compared to lower slew rates or control (no PEMF). The optimal magnetic waveform slew rate for PEMF when applied to orthopedic injuries, both for tissue regeneration and pain reduction, was therefore determined to be => 100 kG/s.