C1-C2 Instrumentation According to Harms/Goel in Case of Vertebral Artery below the Arch of C1: A Case Report

Study Design Case report. Background and Study Aims For stabilizing surgery of the atlantoaxial region, a precise evaluation of the course of the vertebral artery (VA) is essential to avoid vessel injury and life threatening complications. In patients with aberrant VA course, an appropriate way for fusion needs to be found. This article presents a case of an unusual VA course and illuminates the importance of surgical planning with computed tomography angiography identifying VA variations at the atlantoaxial region. Case Report A 71-year-old woman with atlantoaxial arthrosis had a VA variation (persistent first intersegmental artery). She underwent C1-C2 posterior fixation according to Harms/Goel using the typical entry points, requiring VA dissection in caudal direction. The postoperative clinical as well as radiographic result was excellent. Angiography 6 months postoperatively showed the VAs below the C1 screws with normal blood flow. Conclusions Placement of C1 screws in a patient with a persistent first intersegmental VA is possible. Careful VA dissection is the key step for safe screw placement, screw anchoring, and clinical success.