Use of electrical bone stimulation in spinal fusion.

Spinal fusion is commonly done to manage deformity, restore stability, and eliminate excessive motion at specific spinal levels. Pseudarthrosis limits the clinical success of spinal fusion. Three types of electrical stimulation, which is used to manage non-union in long bones, recently have been applied in an attempt to enhance the rate of spinal fusion. Direct current electrical stimulation is internal and thus eliminates dependence on patient compliance. Pulsed electromagnetic fields and capacitively coupled electrical stimulation are external techniques that require patient compliance but do not have the increased risk associated with implantable devices. Firm conclusions about efficacy are difficult to establish because of inconsistencies in both determining a reliable, reproducible end point for fusion and in incorporating the effect of patient parameters. Most data indicate a positive effect for use of direct current stimulation, but further studies are necessary to determine its appropriateness as an adjuvant to spinal fusion.