An injury that affects the C1 vertebrae is often referred to as an upper cervical spinal injury. If the cervical spine injury is a fracture that affects the anterior and posterior arches of the C1 vertebra, it is commonly referred to as an Atlas fracture (because the C1 vertebra is known as the Atlas) or a Jefferson fracture, which is named after the neurosurgeon who named this type of injury. However, it is important to note that a Jefferson fracture does not always result in a spinal cord injury; SCI typically occurs when the transverse ligament also has been ruptured.