[Odontoid fracture combined with lateral atlanto-axial dislocation. Report of two cases]

The authors describe their experience with treatment of two neurologically intact male patients, aged 70 and 74 years, presenting with combined lateral atlanto-axial dislocation and odontoid type II fracture. The mechanism of these two craniovertebral junction injuries had been lateroflexion of the neck. The initial attempt at closed reduction using axial traction failed. The authors succeeded with a closed reduction maneuver under general anaesthesia in the first patient in whom long-term stability was achieved by transarticular C2-C1 fixation, together with interlaminar fusion. In the second patient, closed reduction was unsuccessful due to intra-articular soft tissue interposition. Release and reduction were achieved by instrumentation of C1 lateral masses and transpedicular anchorage of screws into the C2. The subsequent Harms C1-C2 stabilisation proved to be effective both in achieving long-term stability and segmental fusion of lateral masses. Aspects of biomechanics as well as a review of pertinent literature are presented.