Abstract
Background and Objective We present a treatment approach for a rare condition of patients with a ventral C1
fracture and a congenital cleft in the posterior arch (half-ring Jefferson fracture)
with an intact transverse atlantal ligament. Our technique aims to achieve stability
of the atlanto-occipital and atlantoaxial joints while preserving mobility of the
upper cervical spine.
Patients and Methods Two male patients, 43 years and 29 years of age, respectively, were admitted to our
hospital due to a fracture of the ventral arch of the atlas with no damage of the
transverse atlantal ligament. Both men also presented a congenital cleft of the posterior
arch. Initial conservative management with a halo-thoracic vest was performed in one
case and failed. As a result, surgical treatment was performed in both cases using
bilateral C1 mass screws and a transverse connector.
Results The patients showed no neurologic deficits on follow-up examination 4 weeks after
surgery with a full range of head and neck motion. Computed tomography (CT) showed
no dislocation of the implanted material with good dorsal alignment and a stable ventral
fracture distance. Follow-up CT showed osseous stability in both cases with the beginning
of bony ossification of the bone graft.
Conclusion Isolated instable fractures of the ventral arch of the atlas with a congenital cleft
of the posterior arch with no damage of the transverse atlantal ligament can be stabilized
using bilateral C1 mass screws and a transverse connector preserving upper cervical
spine mobility.
Keywords
cervical spine - atlas fracture - congenital cleft - atlantoaxial instability - cervical
anomalies
