Faloon M, et al. - Experts evaluated the long-term effects of posterior paraspinal musculature after posterior fusion for adolescent idiopathic scoliosis. In order to analyze axial images at each level distal to the fusion mass, magnetic resonance imaging (MRI) studies were reviewed. They graded symmetry, muscle quality, and fatty infiltration according to the Goutallier classification of the iliocostalis, longissimus, and spinalis muscles. Very little long-term qualitative fatty degeneration distal to the fusion mass on MRI was demonstrated by the open posterior muscle splitting approach for spinal fusion.