Vertebral artery anomaly with entry at C4--avoiding a surgical pitfall: a case report.

We present a case of an unusual course of the vertebral artery (VA) with intra-foraminal entrance at C4. A patient with traumatic fracture of C3 and C4 with dislocation C3/C4, spinal cord compression and ensuing quadriplegia presented with unilateral entrance of the VA at C4 detected on preoperative magnetic resonance imaging (MRI). The patient was surgically decompressed and stabilized by an anterior-posterior approach without intra-operative complications. Apart from anatomical findings no clinical case of entrance of the VA at C4 had been described in recent clinical literature. A physiologic high entrance of the VA is very rare but must be diagnosed preoperatively to avoid potential life threatening complications.