Objecties. To assess the long-term effects of PLF, AF, or CF for high-grade isthmic spondylolisthesis on lumbar spine in children and adolescents by using MRI.

• 目的：通过磁共振成像，评定PLF、AF、CF对儿童和青少年严重峡部裂型腰椎滑脱症的长期的影响。