Medcyclopaedia Melorheostosis

Description: Melorheostosis a rare bone disorder whose initial manifestations include swelling of joints, pain, and limitation of motion. Eventually profound muscle contractures, tendon and ligament shortening, and soft tissue involvement with severe growth disturbances may ensue. Scoliosis, joint contracture and foot deformities may be seen. Frequently the radiographic alterations are limited to a single limb, more often the lower extremity. Cortical hyperostosis having the appearance of bone excrescences extending along its length resembles candle wax flowing down the side of a lit candle (Fig.1). This hyperostosis may reach the carpus and tarsus as well as the metacarpals, metatarsals or phalanges. In the carpal and tarsal areas, more discrete round foci may resemble the findings of osteopoikilosis, whereas in the flat bones, radiating sclerotic patches are seen. In addition, soft tissue calcification and ossification may result in complete ankylosis of the joint. Scintigraphy reveals areas of increased skeletal accumulation of radionuclide, and MR imaging is also of value in diagnosis. On MR images, bone and soft tissue lesions are of low signal intensity on all pulse sequences. (more)