TRAUMATIC PSEUDOARTHROSIS OF THE DENS AXIS - ETIOLOGY, COURSE AND THERAPY

In a retrospective analysis the significance of internal fixation of u nstable and symptomatic non-union of the odontoid was evaluated. In al l but one cases a type II fracture of the odontoid was the underlying cause for the pseudarthrosis. The time interval between trauma and def initive diagnosis varied between 6 months and 30 years. All patients a sked for medical advice because of acute neck pain; in three cases add itional neurological deficits were notified. In all but one case the p seudarthrosis was classified as unstable on flexion-/extension views. The occurrence of neurological deficits showed a positive correlation with the amount of dislocation of the pseudarthrotic odontoid. Nine ou t of 10 patients underwent internal stabilisation of the non-union. Re operation because of persistent instability/failure of stabilisation h ad to be performed in two cases (22.2%). At follow-up all 9 patients w ere pain-free. The neurological deficits in two patients had improved significantly. According to our experience internal stabilisation in u nstable non-union of the odontoid is recommended to achieve significan t reduction of the pain level. Also improvement of the neurological de ficits can be expected depending on the duration of the symptoms.