Bah, Bah, Back Sheep: Effects of Stimulating Sheep Spines
Electrical currents have been shown to help bones heal faster when used after certain types of surgeries. Nearly 160,000 people underwent spine fusion surgeries in 1995, and many of these patients were implanted with special cages between their spinal bones. Could electrical stimulation have  benefits after spine fusion surgery too?

Medical researchers recently tackled this question by studying the effects of electrical stimulation in the spines of 22 sheep. The researchers chose to use sheep spines because of their similarity to human spines. Each sheep had a discectomy and fusion surgery done on the lower part of the spine. A titanium cage was packed with bone and placed between the bones of the lower spine. The sheep were divided into three groups. One group didn't get any electrical current. The other two groups received two different levels of current through a device attached to the titanium cage.

The sheep were tested every day for the first week, two months after surgery, and four months after the surgery. They went through neurologic exams, X-rays, and biomechanical testing. Tests showed that the group with the highest current had the quickest fusion rates. Healing was slowest in the group that didn't get any electrical treatment.

Human spines won't necessarily react to electrical stimulation the same way as a sheep's spine. But this research suggests that electrical stimulation may help speed healing and improve the rate of fusion in certain types of back surgeries.

Jeffrey M. Toth, PhD, et al. Direct Current Electrical Stimulation Increases the Fusion Rate of Spinal Fusion Cages. In Spine. October 15, 2000. Vol. 25. No. 20. Pp. 2580-2587.