Occipitocervical contoured rod stabilization: does it still have a role amidst the modern stabilization techniques?
Contoured rod is especially useful for PF in cases of congenital AAD with coexisting CIM, cervical scoliosis, sub-axial instability and/or asymmetrical facet joints. In acquired pathologies with three-column instability, inclusion of joints one level above the affected one by using CR, especially enhances stability.
In this family, the autosomal dominant neurohypophyseal diabetes insipidus phenotype cosegregates with a point mutation in a region of the AVP-neurophysin-II gene which codes for the carboxy-terminal domain of neurophysin-II. Although the altered amino acid is not directly involved in AVP binding, the mutation might lead to conformational changes that impair the dimerization of neurophysin-II molecules. This could in turn affect the AVP binding affinity of neurophysin-II or might interfere with the transport of the AVP-neurophysin-II precursor in the AVP-producing cells of the hypothalamus.