1. Imaging Criteria for the Quantification of Disc Degeneration by Timothy L. Tan, Sean L. Borkowski, Sophia N. Sangiorgio, Patricia A. Campbell, and Edward Ebramzadeh JBJS Reviews Volume 3(2):e2 February 10, 2015 ©2015 by The Journal of Bone and Joint Surgery, Inc.

2. Representative T2-weighted MRI scans illustrating the five-tier MRI classification system proposed by Pfirrmann et al.32, which is based on signal intensity, disc height, nucleus and anulus distinction, and disc structure. Timothy L. Tan et al. JBJS Reviews 2015;3:e2 ©2015 by The Journal of Bone and Joint Surgery, Inc.

3. Representative histological sections of an intervertebral disc, demonstrating features of the histological classification system outlined by Boos et al.15 Fig. 2A Moderate chondrocyte cloning (eight to ten cells), with score of 4/5 for cells (hematoxylin an... Timothy L. Tan et al. JBJS Reviews 2015;3:e2 ©2015 by The Journal of Bone and Joint Surgery, Inc.

4. Line graph showing the number of primary discharges for cervical disc degeneration (blue), lumbar and lumbosacral disc degeneration (green), and nonspecific lumbar backache (red) as a function of time from 1993 to 2010 as well as the amount of NIH funding a... Timothy L. Tan et al. JBJS Reviews 2015;3:e2 ©2015 by The Journal of Bone and Joint Surgery, Inc.