Early Occipitocervical Fusion Surgery in a Rare Clinical Encounter of Non-traumatic Atlantooccipital Subluxation (AOS) in Down Syndrome (Trisomy 21)

Subluxation of the atlantooccipital joint in patients with underlying Down syndrome is an extremely rare orthopedic condition. The condition can pose life-threatening risks if not promptly diagnosed and treated in the early stage. Yet, there have been documented cases of survival following atlantooccipital subluxation or dislocation. Atlantooccipital subluxation (AOS) is usually identified during screening in children with Down syndrome for atlantoaxial subluxation (AAS). Therefore, careful evaluation of the atlantooccipital joint from radiographs is also essential. It is crucial to emphasize the clinical significance of AOS. Here the authors present the case of a fifteen-year-old girl with underlying Down syndrome (trisomy 21) who survived a sudden onset of non-traumatic atlantooccipital subluxation with spinal cord compression. There are only a few cases were reported in patients with Down syndrome (trisomy 21) and only two cases with surgically treated atlantooccipital (C0C1) subluxation have been reported. This case is of particular interest as it represents the first reported case of atlantooccipital (C0C1) subluxation with spinal cord compression in Down syndrome that underwent occipitocervical fusion surgery during the acute presentation, resulting in significant neurological recovery. Her neurology symptoms and physical functions showed remarkable improvement post-surgery, and she is doing well at the one-year follow-up in the clinic. Early surgery during acute presentation in this case resulted in good surgical outcomes and improved patient quality of life.