Unilateral C-1 lateral mass sagittal split fracture: an unstable Jefferson fracture variant.
OBJECTIVE
The object of this study was to describe an unusual fracture subtype within C-1 injuries with a propensity to result in late deformity and pain. Most patients with C-1 injuries are nonsurgically treated using external immobilization unless there is an injury of the transverse atlantal ligament. The authors describe an unusual variant involving a unilateral sagittal split with a high tendency to late deformity and pain. They also review the literature and treatment of C-1 fractures.


METHODS
A retrospective review of 12,671 CT scans from a Level I trauma center over a 6-year period yielded 54 patients with C-1 fractures. Among these patients, 6 had an unusual unilateral lateral mass sagittal split, which resulted in a late cock-robin deformity in all survivors and thus a surgical deformity correction with occipital-cervical instrumented fusions. Patient charts and radiographs were reviewed, this fracture subtype is described, and its treatment discussed.


RESULTS
Radiographic studies in 6 patients with C-1 fractures demonstrated a unilateral sagittal split of the lateral mass but an intact transverse atlantal ligament. In the 3 surviving patients, a late cock-robin deformity, significant loss of neck rotation, and severe neck pain developed. Vertebral artery occlusion, as revealed on CT angiography, occurred in 1 patient. All patients were placed in traction and underwent successful occipital-cervical fusion and deformity correction. At the final follow-up, all patients had satisfactory pain relief and improved head alignment.


CONCLUSIONS
Patients with a unilateral sagittal split of the C-1 lateral mass have unstable injuries and must be carefully monitored, with a low threshold for surgical reconstruction or prolonged traction. Patients with late deformity can be successfully treated with occipital-cervical instrumented fusions.
Department of Orthopaedics and Sports Medicine, Harborview Medical Center, University of Washington, Seattle, WA 98104, USA. rbransfo@u.washington.edu
Richard
R
Bransford
Alexis
A
Falicov
Quynh
Q
Nguyen
Jens
J
Chapman
D000328:Adult; D000369:Aged, 80 and over; D000792:Angiography; D001270:Cervical Atlas / Q000293:injuries*; D002574:Cervical Vertebrae / Q000293:injuries*; D006801:Humans; D008875:Middle Aged; D019547:Neck Pain / Q000209:etiology; D012189:Retrospective Studies; D016103:Spinal Fractures / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D014711:Vertebral Artery / Q000000981:diagnostic imaging