This volume contains the papers presented at the International Symposium on Spine and Spinal Disorders in Growth and Aging held in Niigata on November 22-23, 1992. The symposium commemorates the 75th anniversary of the foundation of the Department of Orthopedic Surgery, Niigata University School of Medicine. . The purpose of the symposium was to investigate the field of spine and spinal disorders in growth and aging. Topics ranged from osteoporosis, other of the spinal column to degenerative metabolic bone diseases, and deformity spinal disorders and heterotopic ossification with resultant myelopathy. Spinal manifestations of systemic and local diseases were also included. Symptoms of spinal disorders in both the lower and upper extremity were presented and biomechanics and bone mineral measurement of the spine were also discussed. The organizing committee would like to thank the following for their sponsorship and support of this international symposium: Japan Osteoporosis Foundation, Japan-North America Medical Exchange Foundation, Japan Russia Medical Exchange Foundation, Niigata Prefectural Government, and Niigata City Government. We deeply appreciate their support and contributions to the success of the symposium. The chairman of the organizing committee is most grateful for the contributions and support of the International Advisory Committee, Dr. B.D. Burr (USA), Dr. H.M. Frost (USA), and Dr. R.R. Recker (USA); the Local Advisory Committee, Dr. S. Kono (Prof. Emeritus of Niigata University) and Dr. T. Tajima (Prof. Emeritus ofNiigata University); and the members of the organizing committee, Dr. Y. Watanabe (Yamagata University), Dr. K.