105. Clinical outcomes of C2 nerve root sacrifice and the feasibility of its preservation in patients with congenital atlantoaxial instability

Abstract

<h3>BACKGROUND CONTEXT</h3> Posterior C1-C2 fusion is a widely used fixation technique for atlantoaxial dislocation (AAD). The C2 ganglion is a restricting factor to easy access of C1-C2 joints, and placement of C1 lateral mass screws. Both intentional C2 nerve root sectioning as well as its preservation have been described and are still debatable. The associated complications and outcomes have been less studied, particularly in congenital AAD. <h3>PURPOSE</h3> To study clinical outcome after C2 nerve root sectioning as well as the feasibility of its preservation in AAD patients. <h3>STUDY DESIGN/SETTING</h3> Retrospective study/ tertiary care center. <h3>PATIENT SAMPLE</h3> This study included 190 patients who underwent posterior C1-C2 fusion for congenital AAD. <h3>OUTCOME MEASURES</h3> C2 nerve-related dysfunction; feasibilty of nerve root preservation. <h3>METHODS</h3> This is a retrospective study of 190 patients who underwent posterior C1-C2 fusion for congenital AAD using C1 lateral mass screws. The decision to cut or preserve C2 nerve root was dependent on preoperative radiology and intraoperative suitability of its preservation. Patients were followed-up at periodic intervals and questioned about C2 nerve-related dysfunction. <h3>RESULTS</h3> Complex C1-C2 morphology with highly deformed joints was seen in 139 patients. In 178 patients, the C2 nerve root was sectioned. Postoperative numbness, paresthesia and dysesthesia were present in 30.3%, 21.9% and 19.1% patients respectively. However, the symptoms were bothersome in none. They neither required medications nor disturbed the daily activities of patients. Noticeably, 9 patients (5.1%) developed non-healing occipital ulcers; most needed surgical intervention in the form of a flap cover/skin graft. C2 nerve root preservation is feasible with robust inferior C1 lateral mass and normal sized ganglion. In patients with C1-occipital condyle hypoplasia, highly oblique joints, incurved occiput, pseudofacets and anomalous vertebral artery, its preservation is technically difficult. <h3>CONCLUSIONS</h3> Though C2 nerve root sectioning did not disable the quality of life in many, a subset of patients was prone for neuropathic ulcers. Hence, its preservation should be attempted whenever feasible. It may be possible to preserve it in less complex anomalies/favorable anatomy. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.