New progress in adjacent segment degeneration/disease.

Adjacent segment degeneration/disease (ASD) has been generally accepted as a long-term complication after spinal surgery. Although the incidence of ASD is not very high, it is gradually recognized to be a very important factor in evaluation of the long-term effect of spinal fusion. There are many views concerning pathogenic factors and ways of prevention and treatment. The authors review and discuss the current research and this article will describe recent advances in ASD.