The Spine Journal 15 (2015) 1152–1153
Medial condyle with os odontoideum that has fused to the occiput A 24-year-old man presented to the emergency clinic after a car accident. Physical examination revealed nonspecific neck pain. No history of surgery. Clinical examination revealed spasticity in right lower extremity. The power in the right lower extremity was Grade 2/5 and that in the other extremities was Grade 4/5. There were no definite sensory deficits. Nonenhanced multidetector computed tomography and magnetic resonance imaging were performed. Median (third) condyle of the occipital bone and aplasia of the odontoid process were seen on multidetector computed tomography examination (Fig. 1). That was also posterior dislocation of skull base and narrowing
of spinal canal (Fig. 1). Compression of spinal cord and myelopathic signal showed magnetic resonance imaging (Fig. 2). Patient was operated with posterior decompression and occipitoatlantal fixation technique (Fig. 3). A bone process from the anterior margin of the foramen magnum, called as the median (third) condyle of occipital bone, has been described. This process is usually attached to or may form a joint with the odontoid process, less frequently with the anterior arch of the atlas in the midline, and may be with the aplasia of odontoid process. This anomalous bone can result in neural compression (myelopathy) and vascular compromise and can manifest with abnormalities in the cerebrospinal fluid dynamics. Symptoms differ according to degree of myelopathy, ischemia, and cerebrospinal fluid dynamics. Most of the patients who manifested with neurologic symptoms were in their first and second
Fig. 1. (A) Axial, (B) sagittal, (C) coronal reformat multidetector computed tomography, and (D) volume rendered images of occipitoatlantal region. Median (third) condyle of occipital bone (arrows) showed on three planes, and also odontoid process aplasia showed the same. http://dx.doi.org/10.1016/j.spinee.2015.01.031 1529-9430/Ó 2015 Elsevier Inc. All rights reserved.
M. C¸ akır et al. / The Spine Journal 15 (2015) 1152–1153
1153
Fig. 2. (Left) Sagittal and (Right) coronal T2W images show median (third) condyle of occipital bone (black arrows) and myelopathy (white arrow).
decades of life. Tonsillar herniation may be involved. Multidetector computed tomography is the best diagnostic method for bone anomaly and magnetic resonance imaging is the method for myelopathy [1–3]. There are two surgical methods; anterior transoral decompression followed by posterior fixation and posterior decompression and occipitoatlantal fixation for myelopathy due to median condyle of occipital bone [3]. References [1] Goel A, Shah A. Unusual bone formation in the anterior rim of foramen magnum: cause, effect and treatment. Eur Spine J 2010;19(2 Suppl):S162–4. [2] Kotil K, Kalayci M. Ventral cervicomedullary junction compression secondary to condylus occipitalis (median occipital condyle), a rare entity. J Spinal Disord Tech 2005;18:382–4. [3] Menezes AH, Fenoy KA. Remnants of occipital vertebrae: proatlas segmentation abnormalities. Neurosurgery 2009;64:945–53. discussion 954.
M€urtaza C¸akır, MDa Recep Sade, MDb Hayri Ogul, MDb C glu, MDa ¸ agatay C¸alıko Leyla Karaca, MDb Mecit Kantarci, MD, PhDb a Department of Neurosurgery Medical Faculty Ataturk University Yakutiye Erzurum 25040, Turkey b Department of Radiology Medical Faculty Ataturk University Yakutiye Erzurum 25040, Turkey FDA device/drug status: Not applicable. Author disclosures: MC¸: Nothing to disclose. RS: Nothing to disclose. HO: Nothing to disclose. C¸C¸: Nothing to disclose. LK: Nothing to disclose. MK: Nothing to disclose.
Fig. 3. (Left and Middle) Axial and (Right) coronal reformat multidetector computed tomography images show posterior decompression and operative material (arrows). *Posterior decompression.
Medial condyle with os odontoideum that has fused to the occiput A 24-year-old man presented to the emergency clinic after a car accident. Physical examination revealed nonspecific neck pain. No history of surgery. Clinical examination revealed spasticity in right lower extremity. The power in the right lower extremity was Grade 2/5 and that in the other extremities was Grade 4/5. There were no definite sensory deficits. Nonenhanced multidetector computed tomography and magnetic resonance imaging were performed. Median (third) condyle of the occipital bone and aplasia of the odontoid process were seen on multidetector computed tomography examination (Fig. 1). That was also posterior dislocation of skull base and narrowing
of spinal canal (Fig. 1). Compression of spinal cord and myelopathic signal showed magnetic resonance imaging (Fig. 2). Patient was operated with posterior decompression and occipitoatlantal fixation technique (Fig. 3). A bone process from the anterior margin of the foramen magnum, called as the median (third) condyle of occipital bone, has been described. This process is usually attached to or may form a joint with the odontoid process, less frequently with the anterior arch of the atlas in the midline, and may be with the aplasia of odontoid process. This anomalous bone can result in neural compression (myelopathy) and vascular compromise and can manifest with abnormalities in the cerebrospinal fluid dynamics. Symptoms differ according to degree of myelopathy, ischemia, and cerebrospinal fluid dynamics. Most of the patients who manifested with neurologic symptoms were in their first and second
Fig. 1. (A) Axial, (B) sagittal, (C) coronal reformat multidetector computed tomography, and (D) volume rendered images of occipitoatlantal region. Median (third) condyle of occipital bone (arrows) showed on three planes, and also odontoid process aplasia showed the same. http://dx.doi.org/10.1016/j.spinee.2015.01.031 1529-9430/Ó 2015 Elsevier Inc. All rights reserved.
M. C¸ akır et al. / The Spine Journal 15 (2015) 1152–1153
1153
Fig. 2. (Left) Sagittal and (Right) coronal T2W images show median (third) condyle of occipital bone (black arrows) and myelopathy (white arrow).
decades of life. Tonsillar herniation may be involved. Multidetector computed tomography is the best diagnostic method for bone anomaly and magnetic resonance imaging is the method for myelopathy [1–3]. There are two surgical methods; anterior transoral decompression followed by posterior fixation and posterior decompression and occipitoatlantal fixation for myelopathy due to median condyle of occipital bone [3]. References [1] Goel A, Shah A. Unusual bone formation in the anterior rim of foramen magnum: cause, effect and treatment. Eur Spine J 2010;19(2 Suppl):S162–4. [2] Kotil K, Kalayci M. Ventral cervicomedullary junction compression secondary to condylus occipitalis (median occipital condyle), a rare entity. J Spinal Disord Tech 2005;18:382–4. [3] Menezes AH, Fenoy KA. Remnants of occipital vertebrae: proatlas segmentation abnormalities. Neurosurgery 2009;64:945–53. discussion 954.
M€urtaza C¸akır, MDa Recep Sade, MDb Hayri Ogul, MDb C glu, MDa ¸ agatay C¸alıko Leyla Karaca, MDb Mecit Kantarci, MD, PhDb a Department of Neurosurgery Medical Faculty Ataturk University Yakutiye Erzurum 25040, Turkey b Department of Radiology Medical Faculty Ataturk University Yakutiye Erzurum 25040, Turkey FDA device/drug status: Not applicable. Author disclosures: MC¸: Nothing to disclose. RS: Nothing to disclose. HO: Nothing to disclose. C¸C¸: Nothing to disclose. LK: Nothing to disclose. MK: Nothing to disclose.
Fig. 3. (Left and Middle) Axial and (Right) coronal reformat multidetector computed tomography images show posterior decompression and operative material (arrows). *Posterior decompression.
