Progression of Osteoporosis	

	The inital compression fractures usually occur in the midthoracic region. As bone is progressively lost, the patient loses height and develops a dorsal kyphosis (humpback). Compression fractures occur at the lower dorsal–upper lumbar vertebrae. With further bone loss the kyphosis becomes more marked, the lower vertebrae become more compressed as more height is lost, and the thoracic cage may eventually come to rest on the pelvic brim, producing a ‘pot-belly’ appearance. The radiological appearance of osteoporosis is shown in Fig. 18.19.