Surgical Outcomes for C₂ Tear Drop Fractures: Clinical Relevance to Hangman's Fracture and C_2-3 Discoligamentous...

To analyze characteristics of surgically managed tear drop (TD) fractures of the C₂ axis associated with other injuries such as hangman's fracture and C_2-3 discoligamentous injury as well as treatment outcomes.

A total of 14 patients (eight men and six women) with TD fractures of the C₂ , who were surgically treated at four national trauma centers of tertiary university hospitals from January 2000 to December 2017, were included in this retrospective study. The mean age of the patients was 45.5 years (ranging from 19 to 74 years). The characteristics, surgical treatment methods (anterior fusion vs posterior fusion), and results of 14 TD fractures of the C₂ were analyzed retrospectively. And the clinical relevance between C₂ TD fracture and hangman's fracture and C_2-3 discoligamentous injury was investigated through the co-occurrence between injuries. The mean follow-up time after surgery was 22.6 months (ranging from 12 to 60 months).

Among 14 patients with TD fracture of the C₂ , four patients (28.6%) had anterior TD fracture and 10 patients (71.4%) had posterior TD fracture. All 10 posterior TD fracture patients had anterior C_2-3 displacement. While two of four anterior TD fracture patients had posterior C_2-3 displacement, the remaining two did not. All 14 patients of TD fracture had at least two or more other associated C₂ injuries as well as C_2-3 discoligamentous injuries. About 92.9% (13/14) of the patients had typical or atypical hangman's fracture; 100% (10/10) of the posterior TD fracture patients had hangman's fracture, but 75% (3/4) of the anterior TD fracture had hangman's fracture. At admission, 13 patients were neurologically intact. However, the remaining patient had spinal cord injury with American Spinal Injury Association (ASIA) impairment scale B with C_2-3 bilateral facet dislocation. All four anterior TD fracture patients underwent posterior C_2-3 fusion. While four of 10 posterior TD fracture patients underwent C_2-3 anterior fusion, the remaining six underwent posterior fusion. At last follow-up, 100% (14/14) of the patients achieved solid fusion, and visual analog scale for neck pain was significantly improved (5.9 vs 2.2, P < 0.001). One patient with ASIA impairment scale B had significantly improved to scale D. No major complications occurred.

Our study showed that surgically managed TD fractures of the C₂ showed a high incidence of other associated spine injuries including hangman's fracture and C_2-3 discoligamentous injury. Therefore, special attention and careful radiologic evaluation are needed to investigate the presence of other associated spine injuries including hangman's fracture and C_2-3 discoligamentous injury, which are likely to require surgery.