Subdental Synchondrosis Fracture in Children: The Value of 3-Dimensional Computerized Tomography

Abstract

A case is presented illustrating the usefulness of computerized tomography (CT) with 3-dimensional (3-D) reconstruction for evaluation of a subdental synchondrosis fracture in a child. Odontoid fractures in children less than 7 years of age occur at the subdental synchondrosis and are typically diagnosed with plain x-rays. However, a delay in diagnosis is common as these injuries may not be appreciated on initial roentgenographic evaluation. The authors present a case of a 2-year-old boy with a subdental synchondrosis fracture secondary to trauma. In this patient, plain x-ray and conventional axial CT failed to definitively elucidate the child’s injuries; however, the use of CT with 3-D reconstruction fully delineated the injury. The use of CT with 3-D reconstruction in evaluating children with subdental synchondrosis fractures is a valuable tool for diagnosis. The treatment of synchondrosis fractures of the odontoid process in children is immobilization of the cervical spine.

Odontoid synchondrosis fractures in children

“…9 We have found that MR imaging can help in equivocal cases; a high signal at the synchondrosis and soft-tissue changes at the C1-2 level provide convincing evidence of a synchondrosis fracture (Fig. 2C).…”

The development of the axis vertebra: the key to a topographic classification of dens fractures

“…Consecutively, these findings have been confirmed by a number of researchers [1,2,7,10,11,13]. Since these early observations it has been generally accepted that the subdental synchondrosis is a bipolar growth zone that contributes to the overall heights of the basis of the dens as well as of the vertebral body, and that it is consistently located below the level of C1-C2 articulation.…”

Odontoid Synchondrosis Fracture Treated by C1-2 Polyaxial Screw-Rod Fixation

“…The cartilaginous end plate between the dens and the body of C2 does not ossify until the child is 5 to 7 years old5,15). Therefore, odontoid synchondrosis fractures are common in young children less than 7 years of age3,5,6,10,11,14,15). Conventionally, the first line of treatment for odontoid synchondrosis fractures in children is immobilization in a halo vest3,6).…”