Submandibular approach for the surgical treatment of Hangman's fracture: anatomy with clinical application

Abstract

Objective To investigate the anatomical tips of submandibular approach surgery and evaluate the effectiveness of this approach for the surgical treatment of Hangman's fracture. Methods Major vessels and nerves in submandibular area of 5 corpses were observed. The minimum vertical distance between the hypoglossal nerve and internal branch laryngeal nerve was measured. The corpses included 3 males and 2 females, aged from 39 to 62 years, without the history of cervical related diseases. Twenty-one patients of Hangman fracture treated with submandibular approach surgery were reviewed. There were 14 males and 7 females, aged from 27 to 59 years. According to the Levine and Edwards classification, there were 18 patients of type Ⅱ, 2 type Ⅱa, and 1 type Ⅲ fractures. Surgery techniques and complication prevention tips were discussed. Results Anatomical structures related to submandibular approach were exposed in autopsy. Minimum vertical distance between hypoglossal nerve and internal branch laryngeal nerve was (21.7 ± 3.1)mm. Submandibular approach could expose C2, C3 vertebrae by mild traction, which could be adopted for surgical treament of Hangman's fracture. Patients were followed up for (21.3 ± 8.1)months after surgery. Fracture healing was achieved in all patients. The preoperative syndrome was improved obviously. The overall mean neurological recovery rates were 64.9% by JOA scores. Cerebrospinal fluid leakage was found in 1 patient intraoperatively, which healed uneventfully after gelatin sponge and Surgiflo packing. Hoarseness was found in 1 patient after surgery, which recovered 2 months later without any treatment. Conclusions Submandibular approach can expose the segments that surgical treatment of Hangman's fracture required. Satisfactory results can be achieved after surgry. Being familiar with the anatomical structures of submandibular triangle and the distribution of major vessels and nerves related to surgry are the key factors for successful surgery and reduction of surgical complications. Key words: Cervical spine; Spinal fractures; Surgery; Anatomy, regional; Submandibular approach; Hangman's fracture