Figure 1. The pattern of bone loss in primary hyperparathyroidism. A typical pattern of bone loss is seen in asymptomatic patients with primary hyperparathyroidism. The lumbar spine is relatively well preserved while the distal radius (1/3 site) is preferentially affected. (Reprinted with permission from Silverberg SJ, Shane E, DeLaCruz L, et al. Skeletal disease in primary hyperparathyroidism. J Bone Mineral Res 1989;4:283-291).