Spinal compression fractures in osteoporotic women: patterns and relationship to hyperkyphosis.

A prospective study of thoracic and lumbar spinal fracture distribution and its relationship to thoracic kyphosis was performed in 87 women with osteoporosis. Anterior wedge fractures were most commonly seen in the midthoracic spine and about the thoracolumbar junction, whereas central compression fractures were most common from the first to the fourth lumbar levels. Solitary wedge fractures did not occur above the seventh thoracic vertebra, suggesting that a cause other than osteoporosis must be suspected in any patient with an isolated high thoracic fracture. Analysis of the spinal radiographs obtained in an additional 16 women without osteoporosis revealed that both forms of fracture were unusual in this small group with normal spinal mineralization. The number of anterior wedge fractures in the thoracic spine correlated (r = .546) with the degree of thoracic kyphosis. However, 19% of the women with no thoracic fractures still had thoracic hyperkyphosis. The authors conclude that the hyperkyphosis of osteoporotic women is related to anterior compression fractures but also has contributing nonskeletal factors.