Surgical Management of Hangman's Fracture: A Systematic Review.

Abstract

Hangman's fractures are bilateral fractures of the C2 pars interarticularis produced during hyperextension injuries. The Levine-Edwards classification divides these fractures into 4 categories determined by injury stability. While stable fracture patterns are typically managed conservatively, prolonged traction required in unstable fractures may be superseded by surgery in its practicality. Surgical approaches can be divided into anterior and posterior: the anterior approach allows access to the disc and is used for anterior cervical discectomy and fusion (ACDF); the posterior approach includes C2 direct pedicle screw (DPS), which preserves motion segments and may be done with a minimally invasive surgery (MIS) approach. Multilevel rod and screw fusion provide the strongest biomechanical fixation. This systematic review compares indications, complications, and functional outcomes of different approaches. A search of multiple databases with keywords "hangman fracture," "hangman's fracture," "axis fracture," and "C2 fracture" was conducted; articles were included if they described the surgical technique and included at least one of the primary outcomes: functional outcomes, complication rates, operation time, and blood loss. A total of 1889 abstracts were screened, 137 full text articles were analyzed, and 36 articles were included, yielding a combined total of 627 patients. ACDF was preferred in unstable fracture patterns. Pre- and postoperative visual analog scale (VAS) scores fell in all groups, with MIS DPS producing the lowest VAS scores. Approaches had excellent neurological improvement and fusion rates. Reported complication rates were generally low; self-limiting dysphagia was most common in the anterior approach and higher volumes of blood loss occured with the posterior approach (255.9 mL in open posterior approach, 75.8 mL in MIS, and 64.3 mL in ACDF). All surgical methods of hangman's fracture fixation have their indications and advantages; surgeons should be equipped to perform all options. Anterior approaches may be preferred for their lower blood loss and access to the disc; however, MIS may improve outcomes in posterior approach. This systematic review can assist spinal surgeons in the selection of the most appropriate surgical option for hangman's fracture and allow surgeons to inform patients of the risks and benefits.