Congenital atlanto-occipital dislocation in a patient with Down syndrome: a case report

Abstract

Down syndrome, also known as trisomy 21, is associated with congenital cervical spine abnormalities, including atlantoaxial instability with or without os odontoideum, atlanto-occipital instability, and hypoplasia of the atlas. Herein, we report a case of Down syndrome complicated by congenital atlanto-occipital dislocation. The patient presented with severe cervical myelopathy at 13 years of age after a 10-year follow-up. Radiography and computed tomography revealed os odontoideum protruding into the foramen magnum and congenital anterior atlanto-occipital dislocation. Additionally, a bifurcated internal occipital crest with a thinned central portion of the occipital bone was noted. Magnetic resonance imaging revealed kyphotic alignment of the spinal cord with severe compression at the foramen magnum level. As the neurological impairment was partially improved by halo vest immobilization, we performed in situ O-C2 fusion with an iliac autograft and decompression of the foramen magnum and posterior arch of C1. An improvement was observed immediately after surgery. Two years after surgery, radiography and computed tomography showed solid O-C2 segment fusion. The accumulation of similar cases is essential for determining the prognosis or optimal treatment for this rare congenital condition.

C1 Facetectomy and Ventral Fixation of Occipitoatlantoaxial Complex for Concurrent Congenital Atlanto-Occipital Dislocation and Atlantoaxial Instability in a Toy Poodle

“…The presence of a significant amount of fibrotic scar tissue surrounding the joints and adjacent soft tissues, attributed to chronic factors, caused limited joint motion and impeded the approach to the surgical site and reduction of the dislocation [9,31]. During the ventral approach, it was challenging to remove all the fibrotic scar tissue, especially that on the dorsal side, to facilitate atlanto-occipital realignment.…”

“…In both veterinary and human medicine, traumatic events are the primary cause of AOD, resulting in significant dynamic instability between the atlanto-occipital (AO) joint. However, in humans, it can also emerge in conjunction with conditions such as rheumatoid arthritis, Down syndrome, congenital cervical vertebral fusion, and neoplasia [1,3,[8][9][10]. The paucity of reported cases is potentially due to the rapid progression towards mortality and diagnostic challenges within the veterinary field [11,12].…”

C1 Facetectomy and Ventral Fixation of Occipitoatlantoaxial Complex for Concurrent Congenital Atlanto-Occipital Dislocation and Atlantoaxial Instability in a Toy Poodle

“…AOD in both veterinary and human medicine, though it can also emerge in conjunction with conditions like rheumatoid arthritis, Down syndrome, congenital cervical vertebral fusion, and neoplasia in humans [1,4,8,9]. The paucity of reported cases, potentially due to the rapid progression towards mortality and diagnostic challenges within the veterinary field [10,11].…”