The Vertebral Fracture Cascade: Etiology and Clinical Implications

A vertebral fracture is a marker of bone fragility and is associated with a downward spiral of recurrent fractures known as the vertebral fracture cascade. Etiology of this unfortunate cascade includes bone and muscle loss from immobility, changes in spinal mechanics causing increased loading on adjacent vertebrae, and the development of an increased thoracic kyphosis (hyperkyphosis [HK]). Degenerative disc disease, common in osteoporotic patients, can also cause HK. HK of any etiology has been associated with decreased thoracic extensor muscle strength, unstable gait, increased body sway, decreased physical and pulmonary functions, chronic pain, and increased spinal loads contributing to the vertebral fracture cascade. Preventing this downward spiral requires a multidisciplinary approach that includes early identification, consideration of pharmacologic treatment, early mobilization of the fracture patient, appropriate exercise, and back protection. Exercise should include weight-bearing and muscle-strengthening activities, but caution is needed to avoid undue stress on the back. Physical therapy can be particularly helpful by teaching the patient how to safely perform daily activities and can assist the patient in establishing a safe exercise program that avoids flexion but promotes back extension and weight-bearing activities. Hopefully, these measures will decrease pain, prevent falls, improve posture, prevent additional bone and muscle loss, and potentially abort the devastating downward spiral of the vertebral fracture cascade.