v4.1 Fusion X
Causes: congenital anomalies (Down syndrome), os odontoideum, trauma, and rheumatoid arthritis with transverse ligament incompetence. Measure atlantodental interval (ADI): >3 mm in adults or >5 mm in children suggests instability; consider dynamic flexion–extension views. Symptoms: neck pain, myelopathy signs, vertebrobasilar symptoms; intubation risks in RA. Surgery: posterior C1–C2 fusion (Goel‑Harms C1 lateral mass–C2 pedicle/pars screws) ± transarticular screws; consider odontoidectomy for irreducible ventral compression. Screen at‑risk pediatric/RA patients before anesthesia/surgery.
Which of the following conditions is most commonly associated with atlantoaxial instability due to ligamentous laxity?
In patients with rheumatoid arthritis, what is the mechanism that most commonly leads to atlantoaxial instability?
Which surgical procedure is typically performed for atlantoaxial instability in pediatric patients?
What is a significant risk factor for intubation in patients with rheumatoid arthritis and atlantoaxial instability?
Which imaging modality is most useful for assessing dynamic instability at the atlantoaxial joint?
What is the primary static stabilizer of the atlantoaxial joint?
Which of the following symptoms is least likely to be associated with atlantoaxial instability?
What is the significance of the 'buffer zone' described in Steel's rule of thirds regarding the atlantoaxial region?
In the context of atlantoaxial instability, what is the role of odontoidectomy?
What is the normal range for the atlanto-dental interval (ADI) in children, indicating stability at the atlantoaxial joint?