According to Robert Salter in "Textbook of Disorders and Injuries of the Musculoskeletal System," metabolic bone diseases are the typical cause of soft bone disorders. Such diseases result in soft bones because the osteoid, which is the bone matrix, does not calcify how it should, resulting in bones that bend, twist and fracture. Accordingly, other diseases that affect metabolism result in soft bones as well.
Chronic Kidney Disease
Nadine Tanenbaum and Darryl Quarles state that chronic kidney disease causes soft bones in the chapter "Bone Disorders in Chronic Kidney Disease" from the book "Primer on Kidney Diseases." Chronic kidney disease causes soft bones due to the disease's inclination to cause problems with calcium and phosphate metabolism. Not only can this issue result in soft bones, it can cause a myriad of other related issues including osteopenia, osteoporosis and death.
Chordoma
In the book "Bone and Joint Disorders," Fancis Burgener, Martti Kormano and Tomi Pudas assert that chordoma causes soft bones, particularly in the sacrum, coccyx, clivus and spine. Unlike chronic kidney disease, the reason behind the soft bones is not malnutrition, but rather osteolytic legions, which are localized soft tissue masses comparable to sores. Although this is not an overall softening of any particular bone, chordoma causes similar issues such as bowing, distortions and fractures.
Paget's Disease
Paget's disease is another exception to Salter's assertion. Rather than vitamin deficiencies, Paget's disease is a condition in which both bone degeneration and formation accelerate, though the prior only slightly more than the latter, say Gordon Campell, Juliet Compston and Adrian Crisp in the book "The Management of Common Metabolic Bone Disorders." As a result, bones are less predisposed to breakage than those with osteopenia and osteoporosis are, but have an inclination to bend and deform instead. In this way, Paget's disease is literally chronic soft bones. Unlike many other bone diseases, Paget's disease is geographically specific, appearing mostly in North America, Britain, New Zealand and Australia. Given these areas are demographically similar, researchers and doctors suspect that Paget's disease is hereditary. When left untreated, Paget's disease can result in neurological, spinal, cardiovascular and neoplastic complications as well as a variety of other diseases and death.
References
- "Primer on Kidney Diseases"; Arthur Greenberg and Alfred K. Cheung (editors); 2005
- "Bone and Joint Disorders"; Francis A. Burgener, Martti Kormano and Tomi Pudas; 2006
- "The Management of Common Metabolic Bone Disorders"; Gordon Campbell, Juliet Compston and Adrian Crisp; 1993
- "Textbook of Disorders and Injuries of the Musculoskeletal System"; Robert Bruce Salter; 1999
