Complications in Occipitocervical Surgery.

The occipitocervical junction is formed by the foramen magnum (FM) and the adjacent anatomical structures of the C1 and C2 vertebrae. The FM is formed anteriorly by the basilar part of occipital bone. Anterolaterally, it borders the occipital condyles and hypoglossal canal as well as the jugular foramen. Posteriorly, the FM is formed by the squamous part of the occipital bone with the internal occipital crest. In the midline, named landmarks at the anterior margin are the basion and, at the posterior margin, the opisthion. Vital anatomic structures are located in the FM or pass through. Among these are the medulla oblongata, meninges, anterior and posterior spinal arteries, vertebral arteries, and spinal roots of the accessory nerve. The FM is firmly anchored to the cervical canal via strong ligamentous support.Pathologies in this area can be of congenital, acquired, traumatic, neoplastic, or infectious origin, with the respective surgical indications and approaches depending on the nature and location of the pathology. If the pathology is occipitoatlantal, the occiput is usually involved in surgery. On the other hand, if the pathology is only at the level of C1-C2, surgery may be limited to these two vertebrae.In this section, we present the surgical management of exemplary congenital cases, and we discuss the complications and what needs to be done to deal with them.