Guizzardi Stefano; Di Silvestre, Mario; Govoni, Paolo; Scandroglio, RenatoJournal of Spinal Disorders: February 1994 Original Articles: PDF Only Buy Abstract Summary: This study reports the histological data relative to the effect of pulsed electromagnetic fields (PEMFs) on the evolution of posterior arthrodesis induced in the lumbar vertebrae of 12 adult male Sprague-Dawley rats. After the operation, one group of six rats was stimulated with PEMFs for 18 h per day, by means of a pair of coils fixed to the outside of the cage. A control group of six rats was given no stimulation after surgery. In the groups stimulated with PEMFs an acceleration of the process of bone callus organization was already observed after 4 weeks, and even more so after 8: An early replacement was in fact observed of the newly formed cartilage tissue with primary bone (at 4 weeks) and subsequently with secondary bone (after 8 weeks). Address correspondence and reprint requests to Dr. M. Di Silvestre at Istituto Ortopedico Rizzoli Via Codivilla, 9, 40136 Bologna, Italy. © Lippincott-Raven Publishers.