Instability of the upper cervical spine. Skeletal Dysplasia Group.

Abstract

There are probably about 100 different types of skeletal dysplasia (osteochondrodystrophy), most of them genetic in origin and associated with growth retardation and short stature. Many, in addition, have premature degeneration ofjoints and childhood osteoarthritis.1 Localised structural bony defects are less common, but odontoid absence has been known to occur occasionally. Interest and alarm has also been expressed at the high incidence of atlantoaxial instability in Down's syndrome, variously reported