Adjacent Segment Disease after Lumbar Spine Surgery—Part 2: Prevention and Treatment

Adjacent Segment Disease and Proximal Junctional Kyphosis Based on recently proposed terminology, degeneration that develops at mobile segments above or below a previously operated spinal level is known as adjacent segment pathology (ASP). Within the heading of ASP, radiologic ASP refers to the radiologic changes that occur at the adjacent segment, and clinical ASP refers to the clinical symptoms and signs that occur at the adjacent segment. ASP can occur after any spine surgery and in any region of the spine, including simple decompressions and shortor long-segment fusion surgical procedures. The development of ASP is problematic because it can necessitate further surgical intervention and adversely affect functional outcomes. The fi rst section of this 3-part series focused on description of the risk factors for development of ASP and proximal junctional kyphosis (PJK), and the classifi cation systems that have been developed as a means of creating a more standardized approach for diagnosing and treating these conditions. In part 2 of this review, the focus is on important general concepts in the prevention and treatment of ASP after lumbar spine surgery. As a basis for understanding specifi c methods for prevention and treatment strategies, we also discuss important principles that underlie the pathologic processes involved in the development of these