Synostosis

Synostosis is the abnormal fusion of neighbor bones. It is a type of dysostosis.

Examples of synostoses include: craniosynostosis- being an abnormal fusion of two or more cranial bones, radio-ulnar synostosis- being the abnormal fusion of the radius and ulna bones of the forearm, tarsal coalition - being a failure to separately form all seven bones of the tarsus (the hind part of the foot) resulting in an amalgmation of two bones and syndactyly - being the abnormal fusion of neighboring digits.