Study Design. All cervical spine radiographs of 44 patients with Crouz
on syndrome treated at Great Ormond Street Hospital during the past 10
years were studied. Objectives. To assess the incidence and pattern o
f cervical spine abnormalities of patients with a confirmed diagnosis
of Crouzon syndrome, but particularly regarding progressive fusion. Su
mmary of Background Data. Previous studies into the cervical spine ano
malies in those with Crouzon syndrome have shown an increased incidenc
e of congenital abnormalities compared with the normal population. The
re is some suggestion from previous studies that cervical spine fusion
s are progressive in nature. Methods. All radiographs were reviewed by
the craniofacial team, along with a single pediatric radiologist with
experience in assessment of skeletal dysplasias. Results. Radiologic
abnormalities included ''butterfly'' vertebrae and fusions of the bodi
es and the posterior elements. Evidence of fusion was present in eight
of 44 (18%) of patients. C2-C3 and C5-C6 were almost equally affected
. Black fusions involving multiple vertebrae were seen. Analysis of se
quential studies in 16 patients showed evidence of progression in five
. Conclusions. These results reveal an incidence of fusions that is lo
wer than reported previously. There is radiologic evidence from serial
studies that the fusions are progressive, and because these patients
are children, the fusion process may not be complete, which may accoun
t for the lower incidence of fusions than in previous studies. The pat
tern of fusions is different from that in earlier studies, which may b
e a result of the method of diagnosis because this population is less
likely to include atypical forms of other syndromes [which have a high
er incidence of cervical fusions, particularly at C2-C3). Regarding ot
her congenital anomalies, it appears that butterfly vertebrae are espe
cially prevalent in association with Crouzon syndrome.