A new transpedicular lag screw fixation for treatment of unstable Hangman’s fracture: a minimum 2-year follow-up study

BACKGROUND: A new C2 transpedicular lag screw designed by our team has been used in human cadaver spines for biomechanical testing, and the results showed that the biomechanical properties of the new C2 transpedicular lag screw were better than ordinary screws. The objective of this study is to analyze the clinical efficacy and safety of the new C2 transpedicular lag screw fixation for the treatment of unstable Hangman's fracture. METHODS: From March 2013 to June 2017, 25 patients who had unstable Hangman's fractures were operated on with a new C2 transpedicular lag screw fixation. The patients included 18 males and 7 females whose ages ranged from 31 to 62 years (average 45.4 ± 9.3 years). The cause of the injury was a traffic accident in 17 patients and a fall from height in 8 patients. Other associated lesions included rupture of the spleen (1 patient) and rib fractures (2 patients). According to the Levine-Edwards classification, 17 patients were type II and 8 patients were type IIA, and according to the Frankel Neurological Performance scale, 8 cases and 17 cases were graded as spinal cord injury D and E, respectively. Twenty-three cases received bilateral screw fixation, and 2 cases had unilateral screw fixation because another pedicle was chipped. The whole procedure was accomplished with monitoring by "C"-arm fluoroscopy. RESULTS: The mean follow-up time was 36 ± 12 months and ranged from 24 to 60 months. No obvious symptomatic or radiologic postoperative complications were found during the follow-up period. Six cases were restored from D to E while 2 cases remained D according to the American Spinal Injury Association (ASIA) grade. Pre- and postoperative visual analogue scale (VAS) and Neck Disability Index (NDI) were statistically different (P < 0.001). Osseous union was achieved in all cases, and the range of cervical motion recovered to the normal level up to the last follow-up. CONCLUSIONS: The primary clinical and radiographic efficacies of a new C2 transpedicular lag screw fixation for the treatment of unstable Hangman's fracture were satisfactory. This approach could be considered a simple, effective, reliable, and economic surgical method for managing unstable Hangman's fractures.