C1 Fractures

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The C1 vertebra (atlas) is a closed ring. A fracture of a closed ring necessarily results in at least two areas of ring disruption. These disruptions are customarily accompanied by a spread of the C1 ring fragments as a result of the axial loading mechanism of this injury and the weight of the head. ^[1] Jefferson originally described this type of C1 fracture in 1920. ^[2]  Accordingly, the term Jefferson fracture is also used to denote burst fractures of the ring of C1. 

In addition to anteroposterior (AP) and lateral views, radiographs of the upper cervical spine include the open-mouth view. This view may identify spreading or widening of the lateral masses or asymmetry of the separation of the odontoid from the lateral masses, which, in an appropriately centered radiograph, may be consistent with spreading of the C1 ring or a C1 fracture. Increased overhang of the lateral masses over the C2 facet totaling more than 6.9 mm suggests a fracture with disruption of the transverse odontoid ligament that may otherwise constrain displacement.

Fractures of the ring of C1 may be associated with an odontoid fracture; thus, the combination of the two fractures should be considered. Furthermore, congenital anomalies of the arch (eg, agenesis of the posterior ring) may be present. Anterior subluxation of C1 on C2 may be present and, if so, often indicates a disruption of the transverse odontoid ligament.

The principal treatment is with a halo and vest or cast, which remains an effective current treatment for many of these fractures.

The upper cervical spine is defined by the two most cephalad cervical vertebrae, C1 (the atlas) and C2 (the axis). This region is distinct in anatomic shape and is more mobile than the lower cervical spine, the subaxial cervical spine. The occipital condyles of the head (or the globe) rest upon the lateral masses of C1 (the atlas). These articular facets allow most of the flexion and extension of the head on the neck as the occipital condyles articulate on the atlas. ^{[3, 4, 5, 6]}

The ring of C1 has no vertebral body; the vertebral body that would correspond to C1 is connected or contiguous with the vertebral body of C2 and projects up as the dens (the tooth), also known as the odontoid of C2. Most of the lateral rotation of the neck actually occurs at the C1-2 junction; the remaining motion of the cervical spine is distributed among the subaxial spine vertebral motion segments as a fractional amount (~7%) per level and is less in total than the C1-C2 lateral rotation.

This area of the upper cervical spine is extremely mobile, and its stability is dependent on ligamentous structures. In unresponsive patients or those who are unable to report symptoms or pain, a C1 fracture or an occipital cervical dislocation must be excluded by radiographic screening. Also, displacement of the C1 ring may occur if the capsule or ligaments are disrupted, even without a C1 fracture; hence, the head may be displaced on the neck, and the atlas may also rotate around the odontoid or sustain a fracture of the dens.

The care of any fracture requires attention to the joint above and below. This cervical complex has often been treated as two separable articulations, C0-1 and C1-2, but the three-unit occipitoatlantoaxial complex (C0-C1-C2) articulation is much more functionally relevant.

The significance is the proximity to the brain, brainstem, and upper cervical spinal cord, but that is contrasted with the very significant motion that occurs in this area. Although patients are routinely asked to flex and extend their necks to determine range of motion, some of the motion observed is between the occiput and the atlas, and as the patient rotates laterally, at least 50% of that motion is atlantoaxial.

The stability of the injury depends on the ligaments between the bony structures. On the frontal view, the projecting occipital condyles are supported by the lateral masses (observed as wedges, narrow medially and expanding laterally), resting on the corresponding superior articular surface of C2. Consequently, the lateral masses provide inherent stability because of this bony shape and also illustrate the extent of the instability when this bony structure is disrupted, particularly when these wedges displace laterally.

The projecting condyles of the occiput are stabilized with the occipitoatlantal capsule, as well as anterior and posterior atlanto-occipital membranes. The ligamentum nuchae is a significant stabilizing structure; its specific relevance to the atlanto-occipital axial complex is controversial but should be considered. Connections from the occiput to the axis are the tectorium membrane and the alar and apical ligaments, which do not appear to be bulky enough to be independently significant restraints.

The dentate ligaments (ie, the alar ligament and the apical ligaments) attach to the dorsal lateral surface of the dens and run obliquely to the medial surfaces of the occipital condyles. In 1974, Anderson and D’Alonzo classified a type 1 odontoid fracture as an avulsion fracture of the odontoid tip caused by the apical ligament, suggesting that these ligaments impart a significant degree of stability. ^[7] Modifications aimed at expanding the Anderson-D’Alonzo classification have been proposed. ^[8]  The Roy-Camille system has also been used to classify odontoid fractures. ^[9]

The transverse ligament goes from the medial surface of one side of the atlas to the other side and essentially constrains the axis to rotate around the odontoid in a closed ring of bone and the transverse ligament. As a consequence, the atlas can displace and embarrass the brainstem and spinal cord if this ligament ruptures or if an associated fracture of the odontoid is present as a result of this specific anatomic arrangement.

The ring of C1 is a structural member of the cervical spine. Because it is a ring and because fracture results in disruption of this ring, more than one location is affected.

The fragments have a propensity to shift laterally, both from the weight of the head and from the muscular contraction acting through this articulation; thus, occipital condylar support for the head is lost. The absence of the rigid bony structure and the lack of interconnection or interrelation of the attached ligamentous structures meet the definition of instability, particularly in that the bony protective function of C1 for the neural elements is lost.

Vertebral artery injuries have been reported as a result of C1 fractures, especially with atlanto-occipital dislocations; small excursions of displacement can be fatal. In addition, vertebral artery injuries can occur and have been reported in the absence of severe trauma as a result of cervical traction, chiropractic manipulation, overhead work, or yoga exercises. Hyperextension is customarily accompanied by rotation; when this is not limited by normal restraints, it becomes excessive, severely diminishing blood flow through the vertebral arteries.

This diminished blood flow is a particular problem in the posterior inferior cerebellar artery and may result in Wallenberg syndrome, which is characterized by ipsilateral loss of cranial nerves V, IX, X, and XI with cerebellar ataxia.

Horner syndrome may occur and, in some cases, may involve contralateral loss of pain and temperature sensation; involvement can extend up from a lateral medullary infarct and spread to the basilar superior cerebellar or the inferior cerebral artery, leading to sudden death, quadriplegia, and the locked-in syndrome, in which quadriplegia occurs with loss of lower cranial nerves and only eye-blinking is possible.

The Jefferson fracture most commonly occurs as the result of axial loading on the head through the occiput, which leads to a burst-type fracture of C1. Diving is the most frequent cause of this fracture, when it results from striking the head on an obstacle in shallow water; hence, the national program “Feet first, first time” (North American Spine Society, 2005) provides a motto for diving in unknown waters or shallow collections of water and has been an effective deterrent. ^[10]

The next most frequent cause of this fracture is being thrown up against the roof of a motor vehicle, a car or bus, or even an aircraft, with the forces being distributed to the body through the neck. The third most frequent cause of these injuries is falls onto the head, except in toddlers, who are predisposed to injury from falls because of their disproportionate head size. ^[3]

Less frequently, when a significant rotatory force is exerted, an atlanto-occipital junction dislocation may occur, or the force may also be dissipated through the odontoid as an associated fracture.

Fractures of the atlas account for 25% of atlantoaxial complex bony injuries, 10% of cervical spine injuries, and 2% of all spine injuries. Injury to the cervical spine occurs infrequently in pediatric populations, and although C1 represents only 1-2% of pediatric trauma and 2-10% of all cervical injuries in this population, the associated mortality is 16%.

Patients with Jefferson fractures are expected to heal and have an excellent prognosis for resumption of activity in the absence of associated injuries. Any surgical stabilization severely restricts the motion of the head, because the occipitoatlantoaxial complex represents over 50% of the motion of the head on the trunk.

Platzer et al studied nine patients (average age, 54 years) who underwent anterior plate fixation of an odontoid fracture because of unsuitability for anterior screw fixation. ^[11]  After plate fixation, eight of the nine returned to their preinjury activity level and were satisfied with the treatment; one reported chronic pain and decreased cervical spine motion. Bony fusion was achieved in all patients; reduction or fixation failed in two. These findings suggested that anterior plate fixation may be a practical option for odontoid fractures requiring additional stabilization.

Al Eissa et al performed a retrospective review of 17 patients with isolated C1 and C2 fractures who experienced significant airway compromise. ^[12]  Older age and male gender were found to be significant risk factors. Most patients also exhibited prevertebral swelling, significant degenerative changes, and significant fracture displacement. Of the 17 patients, 12 required intubation and admission to the intensive care unit; four died. The findings suggested that all patients with isolated C1 and C2 fractures should be assessed for potential airway compromise.

Mead LB 2nd, Millhouse PW, Krystal J, Vaccaro AR. C1 fractures: a review of diagnoses, management options, and outcomes. Curr Rev Musculoskelet Med. 2016 Sep. 9 (3):255-62. [Medline]. [Full Text].

Jefferson G. Fracture of atlas vertebra. Report of four cases and a review of those previously recorded. Br J Surg. 1920. 7:407-22.

North American Spine Society. Spinal cord injuries. Available at http://www.knowyourback.org/Documents/SCI.pdf. 2006-2009; Accessed: April 10, 2017.

White AA, Panjabi MM. Clinical Biomechanics of the Spine. 2nd ed. Philadelphia: Lippincott Williams & Wilkins; 1990.

Aebi M. Surgical treatment of upper, middle and lower cervical injuries and non-unions by anterior procedures. Eur Spine J. 2010 Mar. 19 Suppl 1:S33-9. [Medline].

Elgafy H, Dvorak MF, Vaccaro AR, Ebraheim N. Treatment of displaced type II odontoid fractures in elderly patients. Am J Orthop. 2009 Aug. 38(8):410-6. [Medline].

Anderson LD, D’Alonzo RT. Fractures of the odontoid process of the axis. J Bone Joint Surg Am. 1974 Dec. 56 (8):1663-74. [Medline].

Grauer JN, Shafi B, Hilibrand AS, et al. Proposal of a modified, treatment-oriented classification of odontoid fractures. Spine J. 2005 Mar-Apr. 5(2):123-9. [Medline].

Roy-Camille R, Saillant G, Judet T, de Botton G, Michel G. [Factors of severity in the fractures of the odontoid process (author’s transl)]. Rev Chir Orthop Reparatrice Appar Mot. 1980 Apr-May. 66 (3):183-6. [Medline].

Cusimano MD, Mascarenhas AM, Manoranjan B. Spinal cord injuries due to diving: a framework and call for prevention. J Trauma. 2008 Nov. 65 (5):1180-5. [Medline].

Platzer P, Thalhammer G, Krumboeck A, Schuster R, Kutscha-Lissberg F, Zehetgruber I, et al. Plate fixation of odontoid fractures without C1-C2 arthrodesis: practice of a novel surgical technique for stabilization of odontoid fractures, including the opportunity to extend the fixation to C3. Neurosurgery. 2009 Apr. 64(4):726-33; discussion 733. [Medline].

Al Eissa S, Reed JG, Kortbeek JB, Salo PT. Airway compromise secondary to upper cervical spine injury. J Trauma. 2009 Oct. 67(4):692-6. [Medline].

Sugrue PA, Hage ZA, Surdell DL, Foroohar M, Liu J, Bendok BR. Basilar artery occlusion following C1 lateral mass fracture managed by mechanical and pharmacological thrombolysis. Neurocrit Care. 2009. 11 (2):255-60. [Medline].

Li L, Teng H, Pan J, Qian L, Zeng C, Sun G, et al. Direct posterior c1 lateral mass screws compression reduction and osteosynthesis in the treatment of unstable jefferson fractures. Spine (Phila Pa 1976). 2011 Jul 1. 36 (15):E1046-51. [Medline].

De Iure F, Donthineni R, Boriani S. Outcomes of C1 and C2 posterior screw fixation for upper cervical spine fusion. Eur Spine J. 2009 Jun. 18 Suppl 1:2-6. [Medline]. [Full Text].

Krassnig R, Orlandi JA, Tackner E, Hohenberger G, Puchwein P. Computer-aided analysis for optimal screw insertion in lateral mass of C1: An anatomical study. Arch Orthop Trauma Surg. 2017 Mar 29. [Medline].

Costa F, Ortolina A, Attuati L, Cardia A, Tomei M, Riva M, et al. Management of C1-2 traumatic fractures using an intraoperative 3D imaging-based navigation system. J Neurosurg Spine. 2015 Feb. 22(2):128-33. [Medline].

Singh PK, Garg K, Sawarkar D, Agarwal D, Satyarthee GD, Gupta D, et al. Computed tomography-guided C2 pedicle screw placement for treatment of unstable hangman fractures. Spine (Phila Pa 1976). 2014 Aug 15. 39(18):E1058-65. [Medline].

Gallie WE. Fractures and dislocations of the cervical spine. Am J Surg. 1939. 46(3):495-9.

Brooks AL, Jenkins EB. Atlanto-axial arthrodesis by the wedge compression method. J Bone Joint Surg Am. 1978 Apr. 60(3):279-84. [Medline].

Richter M, Schmidt R, Claes L, et al. Posterior atlantoaxial fixation: biomechanical in vitro comparison of six different techniques. Spine. 2002 Aug 15. 27(16):1724-32. [Medline].

Cornefjord M, Henriques T, Alemany M, et al. Posterior atlanto-axial fusion with the Olerud Cervical Fixation System for odontoid fractures and C1-C2 instability in rheumatoid arthritis. Eur Spine J. 2003 Feb. 12(1):91-6. [Medline].

Mark R Foster, MD, PhD, FACS President and Orthopedic Surgeon, Orthopedic Spine Specialists of Western Pennsylvania, PC

Mark R Foster, MD, PhD, FACS is a member of the following medical societies: American Academy of Orthopaedic Surgeons, Orthopaedic Research Society, Pennsylvania Orthopaedic Society, American Physical Society, American College of Surgeons, Christian Medical and Dental Associations, Eastern Orthopaedic Association, North American Spine Society

Disclosure: Nothing to disclose.

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Received salary from Medscape for employment. for: Medscape.

William O Shaffer, MD Orthopedic Spine Surgeon, Northwest Iowa Bone, Joint, and Sports Surgeons

William O Shaffer, MD is a member of the following medical societies: American Academy of Orthopaedic Surgeons, American Orthopaedic Association, Kentucky Medical Association, North American Spine Society, Kentucky Orthopaedic Society, International Society for the Study of the Lumbar Spine, Southern Medical Association, Southern Orthopaedic Association

Disclosure: Received royalty from DePuySpine 1997-2007 (not presently) for consulting; Received grant/research funds from DePuySpine 2002-2007 (closed) for sacropelvic instrumentation biomechanical study; Received grant/research funds from DePuyBiologics 2005-2008 (closed) for healos study just closed; Received consulting fee from DePuySpine 2009 for design of offset modification of expedium.

Jeffrey A Goldstein, MD Clinical Professor of Orthopedic Surgery, New York University School of Medicine; Director of Spine Service, Director of Spine Fellowship, Department of Orthopedic Surgery, NYU Hospital for Joint Diseases, NYU Langone Medical Center

Jeffrey A Goldstein, MD is a member of the following medical societies: American Academy of Orthopaedic Surgeons, American College of Surgeons, American Orthopaedic Association, AOSpine, Cervical Spine Research Society, International Society for the Advancement of Spine Surgery, International Society for the Study of the Lumbar Spine, Lumbar Spine Research Society, North American Spine Society, Scoliosis Research Society, Society of Lateral Access Surgery

Disclosure: Serve(d) as a director, officer, partner, employee, advisor, consultant or trustee for: Medtronic, Nuvasive, NLT Spine, RTI, Magellan Health<br/>Received consulting fee from Medtronic for consulting; Received consulting fee from NuVasive for consulting; Received royalty from Nuvasive for consulting; Received consulting fee from K2M for consulting; Received ownership interest from NuVasive for none.

James F Kellam, MD, FRCSC, FACS, FRCS(Ire) Professor, Department of Orthopedic Surgery, University of Texas Medical School at Houston

James F Kellam, MD, FRCSC, FACS, FRCS(Ire) is a member of the following medical societies: American Academy of Orthopaedic Surgeons, Orthopaedic Trauma Association, Royal College of Physicians and Surgeons of Canada

Disclosure: Nothing to disclose.

C1 Fractures

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