Ma Z, et al. - Clinical data of 71 subjects with degenerative lumbar stenosis who experienced multi-level posterior lumbar spinal fusion between January 2013 and December 2016 were studied to assess the risk factors for upper adjacent segment degeneration (ASD) following multi-level posterior lumbar spinal fusion. A significantly higher percentage of radiographic ASD was noticed in subjects who underwent proximal fixed vertebral lamina and posterior ligamentous complex (PLC) resection. They suggested a preoperative modified Pfirrmann grade greater than 3, a greater degree of preoperative pelvic incidence, and more decompressed levels as the risk factors for upper radiographic ASD following multi-level posterior lumbar spinal fusion surgery.