Failure of C2-3 anterior arthrodesis for the treatment of atypical Hangman's fractures: A three case series

Background: Hangman's fractures (HF) are defined by bilateral fractures of pars interarticularis of the axis. Most can be treated with a collar. However, the treatment strategies for atypical HF (AHF) involve the pedicles, are unstable, and require fusion. Here, we present three cases of AHF that failed anterior arthrodesis warranting repeat anterior (one case), and posterior fusions (three cases). Case Description: One female and two males, ranging from 48 to 69 years of age, presented with AHF. All three were originally treated with C2-3 anterior cervical discectomy/fusion, and all three failed (e.g., resulted in pseudarthrosis/anterolisthesis/instability). The first patient required a secondary C3 corpectomy/C2-4 arthrodesis, with C1-C4 posterior instrumentation. The latter two patients required secondary C1-C3 posterior fusions. For all three patients, 3-12 months follow-up X-rays confirmed the excellent alignment of the instrumentation and bony fusion. Conclusion: Anterior arthrodesis can be utilized to treat AHF, but often fail when addressing AHF. All AHF warranted secondary posterior fusions (e.g., C1-C3 two cases; and C1-C4 one case) and a subset may additionally require more extensive anterior fusions (e.g., C2-C4 with corpectomy of C3).