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The National Osteoporosis Foundation has estimated that more than 100 million people worldwide are at risk for the development of fragility fractures secondary to osteoporosis. In the United States, the lifetime risk of fractures of the spine, hip, and distal part of the radius is up to 40% for women and 13% for men over the age of fifty years. This leads to an estimated 700,000 osteoporotic vertebral body compression fractures each year, of which more than one-third become chronically painful1. Vertebral compression fractures occur in 20% of people over the age of seventy years and in 16% of postmenopausal women2. Not surprisingly, vertebral compression fractures account for a large portion of the more than $17 billion of annual direct costs associated with osteoporotic fractures in the United States3.Osteoporotic vertebral compression fractures are a leading cause of disability and morbidity in the elderly4-6. The consequences of these fractures include pain, progressive vertebral collapse with resultant spinal kyphosis, and systemic manifestations.The pain associated with acute vertebral compression fractures may be incapacitating. In a number of cases, the pain subsides over a period of weeks or months, but it is not uncommon for the pain to become chronic7. Chronic pain after vertebral fracture may result from (1) incomplete vertebral healing with progressive osseous collapse, (2) altered spine kinematics as a consequence of spinal deformity, or (3) the development of a pseudarthrosis at the involved vertebra. Chronic pain associated with vertebral compression fractures often leads to impaired quality of life and depression7,8.Kyphotic deformity in the osteoporotic spine may also create a biomechanical environment favoring additional fractures. The kyphotic deformity shifts the patient's center of gravity anteriorly, creating greater flexion bending moments around the apex of the kyphosis, which increase the kyphotic angulation further and promote additional fractures9-12. Clinical natural history studies have shown that the risk of a new vertebral fracture in the first year after an incident of vertebral compression fracture increases five to twenty-five times above baseline13-15, with the vertebra adjacent to the previously fractured level at particular risk16,17. Many patients with fractures and kyphosis begin doing less because they fear falls and new fractures. This inactivity in turn leads to accelerated osteoporosis and muscle deconditioning7. Because of the kyphotic deformity, paraspinal muscles must exert more force to maintain an erect posture. This prolonged exertion can cause backaches and muscle fatigue. Extreme kyphosis places unusual amounts of strain on the ligaments and other soft tissues. Pressure on the lower rib cage near the pelvic rim can produce substantial loin pain and tenderness18. Prevention of progressive kyphotic deformity or correction of existing deformity may therefore be important both to reduce the risk of fracture at adjacent levels and to prevent the consequences of spinal kyphosis.Vertebral compression fractures have been shown to adversely affect quality of life, physical function, mental health, and survival7,8,19-22. These effects are related to the severity of the spinal deformity and are partly independent of pain7,19. In recent years, researchers have highlighted the impaired pulmonary function that is associated with osteoporotic vertebral compression fractures and spinal deformity23,24. Leech et al. reported a 9% decrease in pulmonary vital capacity for each thoracic vertebral fracture23. Kyphosis can lead to reduced abdominal space with poor appetite and resultant nutritional problems7,25. By shifting the patient's center of gravity forward, kyphotic deformity not only increases the risk of additional fractures26, but also may lead to poor balance, which increases the risk of accidental falls10,27.