Fracture Healing and Microcurrent

Fracture Healing and Microcurrent

1. Fracture healing

   • electrical bone growth generators
     • attempts to produce electromagnetic fields that mimic the normal electrical signals produced by bone or activate bone's piezoelectric properties
     • encourages the deposition of calcium through increased osteoblastic activity
   • Why?
     • bone create a mild electric field when they are healing or growing
       • bone stimulator activates pathways the releases chemicals within the body - chemicals are signals to progress fx healing
       • a bone growth stimulator (BGS) sends more energy to the healing bone surface through either direct current, capacitive coupling, pulsed electromagnetic or ultrasound waves, which helps the bone heal more quickly

2. Generators w/ electrodes implanted within the body use DC

   • (-) lead is placed near the fx site when the electrodes are implanted in the tissues because new bone callus is electropositive
     • generators are applied transcutaneously

3. Invasive DC stimulators

   • involves the surgical implantation of a cathode at the fx site with the production of direct current (DC) e-stim
   • implantable electrodes provide constant stimulation at the nonunion or fx site; used frequently in spinal fusion surgery
   • semi-invasive (semi-implantable) stimulators use percutaneous electrodes (have pins on them) and an external power source
     • no surgery

4. Non-invasive units

   • capacitive coupling and pulsed electromagnetic fields (PEMF) - works using Coulomb's law
     • capacitive coupling, small skin pads/electrodes are placed on either side of the fusion site and worn for 24 hours per day until healing occurs or up to 9 mo
   • PEMF - delivered via tx coils that are placed into a brace or directly onto the skin and are worn for 6-8 hrs per day for 3 d-6 mo
     • AC sinussoidal current interacts with static electrical field

5. Microcurrent

   • no univresally accepted definition or protocol
   • it is a modality that is at the sub-sensory level or a very low sensory level
     • current is less than 1000 microamperes or 1/1000 the amperage of a TENS unit
     • pulse duration is up to 2500 times longer than TENS
       • this is where it increases electrical (phase charge) w/o increasing amplitude
   • the efficacy of this form of stimulation has not been supported overall by the professional literature
     • because many studies lacked sufficient controls
   • it does not attempt to excite peripheral nerves
     • thought to regulate cellular activity by restoring the body's natural electrical balance
     • broad range of waveforms and all types of current parameters are linked together
     • it is believed that there is a restoration of natural balance which allows for healing without "shoking the system"