Torticollis manifest after a minor fall with underlying bony anomalies and a hypoplastic vertebral artery.

The etiologies of torticollis are numerous. We describe a unique patient who presented with torticollis with head tilting to the right after sustaining a minor fall. Computed tomography scan with two and three-dimensional reconstructions revealed an underlying hypoplasia of the right lateral mass of C1 and occipital condyle. Further study with MRI/magnetic resonance angiography showed hypoplasia of the right vertebral artery with compensatory dilatation of the left vertebral artery. We postulate these underlying anomalies predisposed the patient to torticollis, which became apparent after his fall. We discuss the surgical options available, and the rationale for a single C1-C2 transarticular screw with iliac crest bone graft and cable. In the literature, there are four reported cases of vascular anomalies resulting in torticollis. Our patient is the first, to our knowledge, who harbored both bony and vascular anomalies.