If the MRI showed soft tissue interposition( due to fibrous tissue or transverse ligament) at the nonunion site, the chances of successful outcome using odontoid screw are significantly decreased. Suitable cases are mobile odontoid nonunion( 14), reducible nonunion, large odontoid, either transverse or antero-superior or postero-superior fracture pattern, fracture gap less than 2mm( 13), and the odontoid not ankylosed to the anterior arch of the Atlas or the clivus( 13). The technique involves odontoid screw fixation. It is suitable for selected cases of Types II and III odontoid nonunions( 12, 13). This approach addresses the nonunion directly. Surgical intervention may be done via the following approaches anterior, posterior and the combination of the two. The information obtained from the above investigations is important in decision-making and the approach to surgical treatment. The following information can be obtained the state of the spinal cord, the presence or absence of mechanical compression( during flexion and extension), the space available for the cord, and instability.īone scan has no role in the diagnostic workup: it can show increased uptake at the nonunion site for up to two years following the fracture( 3). It can assess the state of both the soft tissue and bone ( 11). It will give the following information ( 11) chronicity of the fracture, the size of the fracture gap, space available for the cord, size of the odontoid, and the presence or absence of Atlanto-Axial subluxation or dislocation. The open-mouth is good in assessing Atlanto-Axial subluxation. Flexion and extension views will assess the stability of the nonunion. Antero-Posterior(AP), open-mouth view, and lateral flexion and extension views are required. Commonly used investigations are, X-rays, Computed Tomography Scan( CT-SCAN) and Magnetic Resonance Imaging(MRI). Is there a place for nonsurgical treatment for odontoid nonunion? Odontoid nonunion without myelopathyĭiagnostic workup of patients with odontoid nonunion is essential for decision-making. Jörg Böhler et al ( 9) emphasized that nonunion of the odontoid is an absolute indication for surgery. The general consensus is that all odontoid nonunions must be fixed( 8). They operated on all these patients and 90% of them improved neurologically. Neurology developed six months to sixty years after the injury. All these patients were initially treated conservatively. A significant number of these patients(76%) had some form of neurology on presentation, mostly due to anterior cord damage.
Odontoid fracture complications plus#
Paradis et al( 2) reviewed 29 patients who had odontoid nonunion plus Atlanto-Axial Instability( AAI). Subluxation can cause spinal cord compression( 2, 6, 7). Nonunion of the odontoid can lead to subluxation of the Atlanto-Axial joints. Odontoid nonunion, whether stable or not, is a potential threat to the spinal cord and the life of the patient. Stable (fibrous) nonunion needs minimal force to cause instability and neurological damage. The natural history of untreated injury is not known( 5). Nonunion of the odontoid is a hazardous situation( 4). The purpose of this article is to review the approach to the management of odontoid nonunion. Essentially, almost half of conservatively treated odontoid fractures ( especially type II) will develop nonunion. Other authors have identified the following risk factors for nonunion fracture gap of more than 1mm, posterior displacement of more than 5mm, and delayed treatment of more than four days. He considered these two factors as the most important. There must be alternative explanations for the high nonunion rate in Type II odontoid fractures.Ĭholavech Chavasiri ( 3) identified risk factors associated with nonunion in conservatively treated odontoid fractures (those treated with Halo vest) : initial displacement and distraction. Additionally, histological examinations of odontoids removed during surgery failed to demonstrate the presence of avascular necrosis as the cause of nonunion. The blood supply of the mongrels' odontoids is similar to that of humans'. Schatzker et al ( 2) showed in experiments using mongrels that interruption of blood supply to the odontoid is not the cause of nonunion. Many authors believe that the major cause of high nonunion rate in Type II is interruption of blood supply to the proximal part of the odontoid. Type II has a high rate of nonunion: 40%-75% in conservatively treated cases.
Types II and III are therapeutically very important. Type 1 fracture is an avulsion type and is managed non-surgically. Odontoid fractures are classified according to Anderson and D'Alonso. The fracture can follow minimal force, especially in elderly patients. Odontoid fractures account for 10%-16% of all cervical spine fractures( 1).
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