A significant number and variety of disorders cause extraskeletal deposition of calcium and phosphate (Table 1). In some, mineral is precipitated as amorphous calcium phosphate or as crystals of hydroxyapatite; in others, osseous tissue is formed. The pathogenesis of ectopic mineralization is generally attributed to one of three mechanisms (Table 1). First, a supranormal “calcium-phosphate solu...

We report a case of ossification of the posterior atlantoaxial membrane associated with an os odontoideum in a 46-year-old woman. She developed myelopathy following a minor motor vehicle accident. The patient underwent posterior atlantoaxial arthrodesis and resection of the ossified lesion and recovered uneventfully. Long-standing atlantoaxial instability might have played a role in ectopic oss...

Ectopic valvular ossification during the course of degenerative valve disease is a relatively rare event. The presence of lamellar bone tissue in human cardiac valve was first documented histologically by Rosenstein over a century ago (1). The frequency of ossification in surgically excised native cardiac valves reported in three large retrospective analyses was 13% (aortic and mitral valves) (...

GNAS/Gnas encodes G(s)α that is mainly biallelically expressed but shows imprinted expression in some tissues. In Albright Hereditary Osteodystrophy (AHO) heterozygous loss of function mutations of GNAS can result in ectopic ossification that tends to be superficial and attributable to haploinsufficiency of biallelically expressed G(s)α. Oed-Sml is a point missense mutation in exon 6 of the ort...

Ectopic ossification refers to the process of new bone formation in sites that normally do not ossify. The auricle is composed of elastic cartilage, and hence is a pliable structure. Auricular ossification is a rare condition that might be caused by injurious processes, including frostbite, physical trauma, and inflammation as well as processes related to metabolic or endocrine disorders. Here,...

Clinical Classification of Pulmonary Calcification and Ossification Proposed Mechanisms of Ectopic Lung Calcification and Ossification Role of Relative and Absolute Calcium Excess Role of an Alkaline Environment Role of Lung Injury or Fibrosis Role of Angiogenesis Imaging Chest Roentgenogram Computed Tomography 99m Tc-MDP Bone Scintigraphy Specific Disorders Pulmonary Metastatic Calcification P...

The deposition of amorphous calcium salts within the soft tissues is variously called mineralization or calcification. Two forms of calcium salts may be found in the soft tissues: calcium pyrophosphate dihydrate and calcium hydroxyapatite. If bony trabeculae are discernible within the mineralized focus the term ossification is used, sometimes prefixed with the terms ectopic or heterotopic. Ther...

During the first month of life, the murine posterior-frontal suture (PF) of the cranial vault closes through endochondral ossification, while other sutures remain patent. These processes are tightly regulated by canonical Wnt signaling. Low levels of active canonical Wnt signaling enable endochondral ossification and therefore PF-suture closure, whereas constitutive activation of canonical Wnt ...

©2004 British Editorial Society of Bone and Joint Surgery doi:10.1302/0301-620X.86B6. 15356 $2.00 J Bone Joint Surg [Br] 2004;86-B:783-7. Heterotopic ossification can be defined as the formation of bone in tissues which normally exhibit no properties of ossification. It is characterised by the rapid development of calcified bone in soft tissues. Ectopic bone can develop from immature osteoid in...