Sagittal profile of the elderly.

Little is known about the natural history of spinal alignment as it ages into the eighth and ninth decades. Fifty asymptomatic volunteers 70-85 years of age (mean 76 years) without any history of spine pain, trauma, or deformity were radiographed in the standing lateral position, from C7 to the pelvis including the hips. Measurements included segmental angulations, kyphosis, lordosis, and C7 plumb line balance. In addition, measurements of sagittal pelvic balance were made (pelvic incidence, tilting, sacral slope, and S1 overhang). Average kyphosis was 52 degrees (range 29 degrees to 79 degrees); the average lordosis was -57 degrees (range -96 degrees to -20 degrees). The C7 plumb line on average fell 40 mm anterior to the posterosuperior corner of S1. The anterior positioning of C7 was also positively correlated with age and decreasing lordosis. This provides further data into the natural history of the aging spine.