Fractures of C2 (Axis) Vertebra: Clinical Presentation and Management Ahmed Bakhsh, Ahmed Alzahrani, Ali Hassan Aljuzair, Umair Ahmed and Hany Eldawoody Int J Spine Surg published online 29 December 2020 http://ijssurgery.com/content/early/2020/12/17/7139 This information is current as of September 27, 2021. Email Alerts Receive free email-alerts when new articles cite this article. Sign up at: http://ijssurgery.com/alerts The International Journal of Spine Surgery 2397 Waterbury Circle, Suite 1, Aurora, IL 60504, Phone: +1-630-375-1432 © 2020 ISASS. All RightsDownloaded Reserved. from http://ijssurgery.com/ by guest on September 27, 2021 International Journal of Spine Surgery, Vol. 00, No. 00, 0000, pp. 000–000 https://doi.org/10.14444/7139 ÓInternational Society for the Advancement of Spine Surgery Fractures of C2 (Axis) Vertebra: Clinical Presentation and Management AHMED BAKHSH, MBBS, MS,1 AHMED ALZAHRANI, MD,2 ALI HASSAN ALJUZAIR, MBBS Sb- Neurosurg (Ottawa),3 UMAIR AHMED,4 HANY ELDAWOODY, MD, PhD5 1Prince Mohammed Bin Abdulaziz Hospital, Riyadh, Kingdom of Saudi Arabia, 2Security Forces Hospital, Riyadh, Kingdom of Saudi Arabia, 3Prince Mohammed Bin Abdulaziz Hospital, Riyadh, Kingdom of Saudi Arabia, 4Wah Medical College, Wah, Pakistan, 5Department of Neurosurgery, Mansoura Faculty of Medicine, Mansoura University, Egypt, and Prince Mohammed Bin Abdulaziz Hospital, Riyadh, Kingdom of Saudi Arabia ABSTRACT Background: Injuries of the upper cervical spine are a major cause of morbidity and mortality due to associated spinal cord and head injuries. The injury patterns of the upper cervical spine are numerous, and the neurologic sequelae are diverse. The axis (C2) is the most commonly fractured vertebra in the upper cervical spine; its unique anatomy and architecture pose difficulties in the diagnosis and the management of its fractures. Methods: All cases of acute spinal injuries at Prince Mohammed Bin Abdulaziz Hospital in Riyadh, Saudi Arabia, were screened for fractures of C2 vertebrae. These patients underwent computerized tomography (CT) imaging of the cervical spine with special attention paid to the cranio-cervical junction. Magnetic resonance imaging (MRI) and angiography of the neck were performed to exclude ligamentous tears and vascular injuries. Unstable fractures were fixed surgically. In the remaining cases, a conservative trial was given. All patients were followed up once every 3 months for a period of 1 year. During follow-up, some patients underwent additional CT imaging of the cervical spine to monitor the healing of fractures. Results: Out of 230 spinal trauma patients, 43.5% suffered from cervical spine injury. C2 fractures were recorded in 26% cases, and fractures of the C2 vertebral body, including pedicles, laminae, lateral masses, and articular processes, were found in many cases, followed by odontoid fractures (50%). No case of atlanto-axial or atlanto-occipital dislocation was recorded. Road traffic accidents were found to be responsible for 92% of cases. The majority of patients were young males, and 96% of patients had no neurological deficit. Only 15% of the patients required surgery for their unstable fractures. Half of the patients attended outpatient follow -up appointments, all of whom underwent CT scanning of the cervical spine 9 months after the accident or operation. Conclusions: The axis (C2) is the most commonly affected vertebra in cervical spine trauma, and odontoid fractures make up 50% of all C2 fractures. C2 fractures rarely cause any neurological deficit or vascular injury, and the majority of affected patients can be managed conservatively; only a small proportion requires surgical intervention. Surgical intervention leads to early and complete healing. Cervical Spine Keywords: cervical spine, fractures, axis, odontoid process, nonhealing BACKGROUND these segments would undoubtedly cause this motion to be permanently lost.3 It is essential to be familiar with the complex There is no universally accepted classification anatomy and kinematics of the upper cervical spine. system for upper cervical injuries, such as the It is composed of occipital condyles, the atlas, and Subaxial Injury Classification System) and the the axis along with atlanto-occipital and atlanto- Thoracolumbar Injury Classification System.4 Occip- axial joints. The apical, alar, and cruciate ligaments ital condyle fractures are classified by Anderson and constrain the movements of the atlanto-axial Montesano. Atlas fractures are classified into type I articulation. Other ligaments supporting the cervical (posterior arch fractures), type II (anterior arch spine are anterior and posterior longitudinal liga- fractures), type III (Jefferson fracture), type IV ments along with the posterior ligament complex.1,2 (lateral mass fractures), and type V (transverse The C1–C2 complex allows 50% of all the rotation fractures of the anterior arch). Anderson and of the entire spine and 108 of flexion-extension and D’Alonzo classified odontoid fractures into 3 types. 50 degrees of axial rotation. Therefore, the fusion of Type 2 odontoid fractures are further classified by Downloaded from http://ijssurgery.com/ by guest on September 27, 2021 Copyright 2020 by International Society for the Advancement of Spine Surgery. Fractures of C2 (Axis) Vertebra Apfelbaum into 3 subtypes, depending on the Bin Abdulaziz Hospital in Riyadh, Saudi Arabia. direction of the fracture line: type 2a, where the line between January 2017 and June 2018 were screened is anterior oblique; type 2b, where the line is posterior for second cervical (axis) fractures. Patients with oblique; and type 2c, where the line is horizontal. chronic spinal injury, operated spinal injury, firearm Hangman’s fractures (axis ring fractures) are classi- injuries, or autoimmune and congenital bone fied by Effendi et al and modified by Levine and diseases were excluded from the study. Edwards.5 A locked C2–C3 facet joint constitutes a In the emergency department, all cases were type III lesion in both classification systems. The managed according to advanced trauma life support Traynelis classification divides atlanto-occipital dis- protocols. All patients had a whole-body comput- locations into 3 types. Horn et al propose another erized tomography (CT) scan including the cervical classification in which grade I lesions have moder- spine. In those who had positive CT findings or were ately abnormal findings on MRI and grade II lesions symptomatic with normal CT scans, magnetic have grossly abnormal findings on MRI.6 Fielding resonance imaging (MRI) was performed to rule and Hawkins classify rotatory atlanto-axial instabil- out any ligamentous tears and vascular injury. CT/ ity into four types: (1) rotatory subluxation without MRI angiography of the neck was performed in any anteroposterior translation, (2) rotatory sublux- selected cases where there was a strong suspicion of ation with an anterior shift of 3–5 mm, (3) rotatory vascular injury. The severity of spinal cord injury subluxationwithananteriorshiftof.5 mm, and (4) was quantified using the American Spinal Injury rotatory subluxation with a posterior shift.7,8 Lesions Association grades. of the transverse atlanto-axial ligament are classified In all cases, the neck was immobilized with the according to De La Caffiniere` et al.9,10 These hard cervical collar. In polytrauma cases, patients different types of classification systems clearly show were first stabilized and cleared by the trauma how complex this area is and how difficult it is to surgery teams. Patients with unstable fractures agree on a unanimous and unified universal classifi- underwent elective surgery in the form of odontoid cation system for this area. This is why controversies screw insertion or anterior/posterior C1–C2 fusion exist regarding the true management of different and fixation. Patients who did not require surgery types of fractures in this complex area. were managed conservatively in the form of a neck Fractures of the second cervical vertebrae are collar and pain medication. CT scans of the neck commonly seen in spine surgery. These fractures were performed to check the spine alignment and account for approximately one-third of all cervical implant position in all operated cases. All patients spine fractures. The etiology for these fractures is were discharged home with a Philadelphia collar either high-energy mechanisms in younger patients and advised to attend for the regular follow-up. CT or low-energy trauma in the older population.11 imaging of the cervical spine was repeated 9 months Odontoid fractures are the most common subset in later in follow-up cases to observe for evidence of C2 vertebral injury. Their main issue is nonunion fusion/healing. and delayed myelopathy. There are also no treat- ment guidelines available for odontoid fractures. RESULTS For type I and type III fractures, immobilization In total, 230 cases of spinal trauma were assessed yields the best results in many cases. For type II in the emergency department during a period of a fractures, halo vest immobilization and posterior year and a half. One hundred patients suffered from fixation provide similar fusion rates. Anterior a cervical spine injury. Twenty-six patients had C2 fixation appears to increase the fusion rate. Never- fractures either isolated or associated with C1 and theless, the optimum treatment strategy is still C3 fractures (Figures 1–6). Fifty percent were debated and controversial.12 odontoid fractures (Table 1). Ninety-six percent of In this study, we shall examine the frequency of patients were male, and 73% of patients were less C2 fractures, their subtypes, and their management than 50 years old (Table 2). Road traffic accidents in cervical spine injuries were responsible for the injury in 92% of cases. One-third of patients had polytrauma involving METHODS chest, abdomen, and long bone injuries. Ninety-six All patients with an acute spinal injury with or percent of patients remained neurologically intact. without polytrauma admitted at Prince Mohammed One patient was paraplegic due to his concomitant Downloaded from http://ijssurgery.com/ by guest on September 27, 2021 International Journal of Spine Surgery, Vol. 00, No. 00 0 Bakhsh et al. Figure 4.