Malformations of the occipito-vertebral hinge destabilize the bones and injure the neural structures of the bulbo-spinal junction and of the cervico-spinal cord. The Authors have found the Gilles Bertrand intra-articular C/1-C/2 bilateral arthrodesis to be an extremely efficient surgical procedure for stabilizing the occipito-atlo-axial region, producing a relative lowering of the odontoid and relieving pressure in the occipito-atloid region. Excellent post-operative results derive from the relatively easy and non-destabilizing operative procedure. No deaths have been recorded in connection with this operation. This contrasts with the traditional occipito-atloid pressure-relieving procedure (either with or without opening of the dura mater), a procedure which, in addition to not stabilizing the upper cervical spine, sometimes results in the patient's death.