Comparative Study Between Anterior Plate Fixation and Pedicle Screw Fixation of Hangman Fracture

Materials and Methods: From 1987 to 2001, eighteen of 26 cases were treated by anterior plate fixation and 8 of 26 treated by transpedicular screw fixation. Two of 8 cases were in unilateral screw fixation and six of them in bilateral fixation. Two cases of transpedicular screw fixation group were treated by additional posterior plate fixation. Operative indication was unstable fracture that is, over 3.5mm of anterior displacement, over 10º of angulation, such as Levine type II, IIA, III, and IA with rotation force. Postoperatively, philadelphia orthosis or soft collar applied for 6 to 8 weeks.

Results: All cases had achieved bone union in two groups. One case of neck pain, three cases of neck motion limitation and three cases of kyphotic deformity over 10degree were observed in posterior transpedicular screw fixation group. As the surgical complications, two cases of transient dysphagia were observed in anterior plate fixation group and two cases of screw maposition in transpedicular screw fixation group. Transpedicular screw fixation technique had some problems, such as large operative wound scar, large volume of bleeding, kyphotic deformity due to extensive posterior cervical muscle dissection, and technical difficulty.

Conclusion: Both of anterior plate fixation and transpedicular screw fixation methods are useful treatment methods for Levine type II, IIA and III hangman fracture to get the early bone union and early rehabilitation. Anterior plate fixation technique is easier and fewer complications than posterior transpedicular screw fixation, so transpedicular scew fixation method should be confined to the management of type IA fracture with rotational displacement.