UCLA Radiological Sciences Proceedings

Klippel–Feil syndrome (KFS) is a congenital spinal anomaly characterized by the fusion of two or more cervical vertebrae. While the classic triad includes a short neck, limited cervical mobility, and a low posterior hairline, many individuals remain asymptomatic. Diagnosis is often made incidentally through imaging or in adulthood, when symptoms emerge following minor trauma. Radiographically, KFS is identified by non-segmented cervical vertebrae and may be accompanied by anomalies including Chiari malformation or scoliosis. Although KFS is often benign, severe manifestations, such as congenital cervical dislocation, can occur. We present a rare case of congenital cervical dislocation in a 6-year-old boy with KFS and progressive spastic quadriplegia. Serial magnetic resonance imaging and computed tomography revealed worsening anterior subluxation and severe cervical stenosis, prompting multiple complex surgical interventions. This case highlights the essential role of multimodal imaging in the diagnosis and monitoring of, and surgical planning for, severe KFS-related cervical instability.