Case Report: Multimodal imaging, custom 3D-printed reconstruction and surgical stabilization of severe congenital occipitoatlantoaxial malformation in an adult dog.

Occipitoatlantoaxial malformations can vary in severity and clinical signs. A 1.8-year-old male intact Goldendoodle was presented with an acute onset of tetraparesis and severe neck pain after a fall. Neurologic examination revealed non-ambulatory tetraparesis with notable pain upon palpation of the cervical spine. Advanced imaging showed right-sided spinal cord compression at the level of C1 with an abnormal angle of the cranial cervical spine, severe congenital malformations including right atlantooccipital fusion, C1 and C2 hemivertebrae with variable hypo- and aplasia, and atlantalization of the axis (C2). An occipitoatlantoaxial stabilization was performed by a combination of intra-operative imaging with a 3-dimensional C-arm and 3-dimensional printed reconstruction of the occiput to C4 of the patient. The patient improved neurologically following surgery. This is the first documented case of an occipitoatlantoaxial malformation that was surgically stabilized using intraoperative 3-D imaging and custom 3-dimensional printed approach.