Segmental degenerative changes adjacent to prior cervical spine arthrodesis have been frequently reported. When these degenerative changes are associated with the development of new neurological symptoms, such as radiculopathy or myelopathy, the clinical diagnosis of adjacent segment disease is made. A multitude of factors have been postulated to influence adjacent segment degeneration. These include the length of the fusion, loss of normal alignment, pre-existing spondylosis at the adjacent regions, and the stiffness of the implant. Many of these studies have been based on biomechanical evaluations of the implant-biological milieu, but the clinical aspects of the patient's symptomatology have led to questions regarding the role of degenerative spondylosis and the subsequent development of adjacent segment disease. This article will review the literature regarding adjacent segment disease after cervical fusion and discuss treatment strategies, including pre-emptive treatment based on defining two subsets of this patient population.