Cervical spine in the Apert syndrome

Radiographs of the cervical spine-in many cases longitudinal-were available for study in 68 cases of Apert syndrome. Autopsy material was available in one of these cases, and a 3-dimensional reconstruction from a CT scan was also studied in one case. Variable degrees of fusion were observed, involving the articular facets, the neural arch or transverse processes, or block fusion of the vertebral bodies. Ossification may not always be evident in some early radiographs. However, early radiographic signs of impending fusion may be irregularity in vertical orientation of the vertebral bodies and narrowing of the involved intervertebral spaces. Cervical fusions occurred in 68%, single fusions being found in 37%, and multiple fusions in 31%. C₅-C₆ fusion was most common, alone or in combination with other fusions. In contrast, cervical fusions are known to occur in 25% of Crouzon patients, most commonly involving C₂-C₃ only. It appears that when fusions are present, C₅-C₆ involvement in the Apert syndrome and C₂-C₃ involvement in the Crouzon syndrome separate the 2 conditions in most cases. Because cervical anomalies may complicate an already compromised airway in any form of acrocephalosyndactyly, it is imperative to initiate radiographic study of the cervical spine before undertaking anesthesia for surgery.