Atlantoaxial Instability in Individuals with Down Syndrome: A Fresh Look at the Evidence.

Atlantoaxial Instability in Individuals with Down Syndrome: A Fresh Look at the Evidence

Davidson RG (McMaster University, Hamilton, Ontario, Canada), Pediatrics 81:857-864, 1988.

In 1984 the Committee on Sports Medicine of the American Academy of Pediatrics made recommendations restricting children with Down syndrome from participating in sports that involved potential trauma to the neck and head because of the possibility of atlantoaxial instability. The purpose of this article was to review the literature to determine the validity of recommendations made by the Committee.

A review of literature concerning the prevalence of dislocation of the upper cervical spine in those without Down syndrome provided no data regarding the incidence of atlantoaxial dislocation in the general population among relatively asymptomatic individuals who were not subject to major trauma of the head or cervical spine. Case studies were published on the prevalence of atlantoxial instability in asymptomatic individuals and those with atlantoxial dislocation and neurological consequences with Down syndrome. These showed little support for the hypothesis that atlantoaxial instability is a predisposing factor to dislocation, although the author found a need for carefully designed longitudinal studies.

The author drew several conclusions after reviewing the literature: 1) The general laxity of ligaments characteristic in individuals with Down syndrome includes the ligaments of the upper cervical spine; 2) there were no data to determine the incidence of atlantoaxial dislocation among individuals with Down syndrome or in those without Down syndrome, and there was no evidence to indicate that congenital anomalies of the odontoid process among individuals with Down syndrome predispose them to dislocation; 3) there was no evidence that current roentgenographic criteria of atlantoaxial instability were predictive of a tendency to dislocate; 4) among individuals with Down syndrome who did dislocate, the event was preceded by several weeks by neurological signs; 5) the potential exclusion of individuals with Down syndrome from many sports on the basis of the evidence published to date appeared to be unwarranted; and 6) a physical exam with careful attention to neurological signs conducted before participation in sports was found to be more predictive of potential dislocation than were the radiologic criteria recommended in the literature.