Unique Features of Herniated Discs at the Cervicothoracic Junction: Clinical Presentation, Imaging, Operative Management, and Outcome after Anterior Decompressive Operation in 10 Patients

Abstract

Disc herniations at the C7-T1 level are unusual (4% of all herniated cervical discs) and are often incorrectly diagnosed because of unusual neurological findings and suboptimal imaging studies. Furthermore, the anterior approach may be problematic because the manubrium and slope of the vertebral bodies away from the surgeon obscures the end plates. The recurrent laryngeal nerve and the thoracic duct may be injured by respective right- or left-sided approaches. A posterior approach to this level has, therefore, been advocated, but results of C7-T1 herniations treated anteriorly have not been specifically addressed in the literature. We, therefore, reviewed our experience in the operative management of patients undergoing single level anterior cervical discectomy and fusion at the C7-T1 interspace for the 10 years ending June 2004 with regard to clinical presentation, imaging, problems of operative exposure, and neurological outcome. Of 268 patients with single level anterior cervical discectomy and fusions (ACDFs), 10 (3.7%) had C7-T1 disc herniations. We retrospectively reviewed the medical records, operative reports, and imaging studies of these 10 patients. All patients presented with C8 motor deficit without myelopathy. The operation was carried out through an anterior approach with a skin incision 3 cm above the clavicle. Visualization of the C7-T1 disc space was achieved in all without difficulty. Eight of 10 patients are neurologically intact. The C7-T1 disc herniates laterally because of the absence of Luschka joints at this level. Central herniation with myelopathy is rare. An anterior approach was easily accomplished in all patients. Recovery of motor function was related to duration and severity of preoperative deficit.