Os odontoideum: Report of three cases

Coluna/Columna, 2012

Objective: To report the difficulties in managing a case of os odontoideum. Methods: Female patient, 12 years old who developed a quadiparesis after minor cervical trauma in October 2005. In the emergency department a congenital cervical anomaly was identified. The patient was placed in a Stryker ® frame and, few days later, in a halo bracing. After 3 months, an infection around the pins emerged and the halo vest had to be removed. A severe C1-2 instability persisted and a C1-C2 Gallie procedure was attempted. In the following weeks the bone disappeared and another procedure was attempted in June 2006 -C1 laminectomy and occiput-C3 fusion. In the following months the neurological status of the patient improved and a complete mass of occiput-C3 fusion was observed. Results: We choose a posterior cervical arthrodesis of C1-C2 using the Gallie technique. Since the condition was not resolved we performed a second surgery, C1 laminectomy (determined by SAC of 8, 3 mm in MRI) followed by posterior occiput-C3 fusion. In our case, until now, there is no evidence of axial decompensation, but a more prolonged follow-up is needed. Conclusions: The treatment of os odontoideum has many considerations but the essential that in the presence of instability and neurological deficit a solid fusion is achieved. In case of failure of posterior atlantoaxial wiring, the occiput-C2 or C3 fusion with rods seems to be an excellent option with a high rate of success, avoiding the need for additional support.

Injury, 1995

JPMA. The Journal of the Pakistan Medical Association, 2008

Os odontoideum can lead to atlantoaxial instability, which can be either reducible or a fixed dislocation. We present surgical management in four patients with os odontoideum at our center. Two of these had reducible dislocations and were managed by posterior transarticular screw fixation. Other two had fixed dislocations necessitating posterior decompression and occipitocervical fixation.

2001

Cervical vertebral anomalies are often associated with malformations or traumas, they may be completely asymptomatic and represent an occasional finding in vertigo or can cause severe neurologic complications (ie, compression of the upper cervical spine with myelopathy, epilepsy, or respiratory failure). This clinical case is a patient who came to us for observation for a peripheral harmonic vestibular syndrome, and in whom a malformation of the cervical vertebral joint (os odontoideum) was occasionally found on magnetic resonance imaging.

Bangladesh Journal of Child Health

Os odontoideum (OO) is a rare condition defined radiographically as an oval or round-shaped ossicle of variable size with smooth circumferential cortical margins representing the odontoid process that has no continuity with the body of second cervical vertebra (C2). Since the upper cervical spinal region is complex from anatomical point of view and has many vital structures passing in close relation to each other it is important to review this topic. If a person suffers from hyper mobile dens due to insuffiency of its ligamentous complex, it may cause translation of the atlas on the axis and may compress the cervical cord or vertebral arteries. However, patients with this condition may be asymptomatic or may be symptomatic of a variety of neurological deficits and vascular dysfunctions. There are cases where patients suffering from Os odontoideum became quadriplegic after a minor trauma. The treatment of both the asymptomatic and symptomatic characteristics of this condition has und...

Caribbean medical journal, 2022

Os odontoideum is a rare cause of atlantoaxial instability. Despite being first described in 1886, its pathogenesis is still unclear, with theories for both congenital and traumatic etiologies. We report on an atypical presentation of this pathology, in a patient who was being investigated for recurrent syncopal episodes during performance of everyday activities, and who was unexpectedly found to have an os odontoideum. The patient underwent occipitocervical fusion and had complete resolution of all her symptoms postoperatively.

World Neurosurgery, 2017

Introduction: Os odontoideum is an uncommon abnormality of the craniovertebral junction where the tip of the odontoid process lacks continuity with the body of C2. The clinical presentation is variable but can lead to severe neurological impairment. Case report: We report the gross and radiological findings of a cadaver found to harbor an os odontoideum. Conclusion: To our knowledge there are no cadaveric reports in the literature regarding an os odontoideum. Such a case allows a rare window into the anatomy and relationships of this pathological structure.

Neurosurgery, 2013

P lain radiographs of the cervical spine (anterior-posterior, open mouth-odontoid, and lateral) and plain dynamic lateral radiographs performed in flexion and extension are recommended to diagnose and evaluate os odontoideum, with or without tomography (computerized or plain) and/or magnetic resonance imaging of the craniocervical junction.

Indian Journal of Orthopaedics, 2010

Background: Os odontoideum (OO) with C1-2 anterolisthesis and retrolisthesis may cause cervicomedullary injury both from anterior and posterior aspects. We analyzed fourteen such patients for biomechanical issues, radiological features and management of OO with free-floating atlantal arch and review pertinent literature. Materials and Methods: Fourteen patients having nonsyndromic, reducible atlantoaxial dislocation (AAD) with orthotopic OO were analyzed. During neck flexion, their C1 anterior arch-os complex displaced anteriorly relative to remnant odontoid-C2 body. The posteriorly directed hypoplastic remnant odontoid sliding below the atlas and forward translation of the C1 posterior arch caused concomitant cervicomedullary compression. During neck extension, there was retrolisthesis of the "free-floating" C1 archos complex into spinal canal. Spinal stenosis and lateral C1-2 facet dislocation; Klippel-Feil anomaly; and posterior circulation infarcts were also present in one patient each, respectively. Posterior C1-2 (n=10) or occipitocervical fusion (n=3) was performed in neutral position to stabilize atlantoaxial movements. Results: Follow-up (mean, 3.9 years) assessment revealed improvement in spasticity and weakness in 13 patients. One patient had neurological deterioration following C1-2 posterior sublaminar fusion, requiring its conversion to occipitocervical contoured rod fusion. One patient with posterior circulation stroke died prior to any operative intervention. Follow-up lateral view radiographs showed a bony union or a stable construct in these 13 patients. Conclusions: OO with free-floating atlantal arch may precipitate cord injury both during neck flexion and extension. This condition may be overlooked unless lateral radiographs of craniovertebral junction are undertaken in neck extension, along with the usual ones in neutral and flexed positions. Etiological factors include C1 ring-OO unrestrained movements above the hypoplastic odontoid; upward pull on OO by alar and apical ligaments; lax C1-2 facet joint ligaments; and congenital presence of horizontal facet joint surfaces that facilitates C1-2 translation.

European Spine Journal, 2011

Introduction Odontoid diameter in some individuals may not be large enough to accommodate two 3.5-mm cortical screws for anterior odontoid fracture fixation. The study was performed to evaluate, in a Brazilian population, the diameter of the odontoid process and the feasibility of using two 3.5-mm cortical screws for anterior odontoid fracture fixation. Materials and methods Computed tomographic (CT) scans of 88 adult patients (aged 18-78 years) were analyzed; 40 patients (45%) were male (mean age: 43.08 years) and 48 (55%) were female (mean age: 43.39 years). The minimum external and internal anteroposterior and transverse diameters of the odontoid process on sagittal and coronal planes were measured on CT multiplanar reconstructions of the cervical spine. Results The mean value of the minimum external anteroposterior diameter was 10.83 ± 1.08 and 7.53 ± 1.10 mm for the minimum internal anteroposterior diameter. The mean value of the minimum external transverse diameter was 9.19 ± 0.91 and 6.07 ± 1.08 mm for the minimum internal transverse diameter. The mean AP diameter was significantly larger than the mean transverse diameter; 57 (65%) individuals had the minimum external transverse diameter [9.0 mm that would allow the insertion of two 3.5-mm cortical screws with tapping, and five (6%) individuals had the minimum internal transverse diameter [8.0 mm that would allow the insertion of two 3.5-mm cortical screws without tapping. Conclusions The insertion of two 3.5-mm cortical screws was possible for anterior fixation of odontoid fracture in 57 (65%) individuals of our study, and there was no statistical difference between males and females.