Type ⅡaHangman Fracture Mechanical Instability And Choice Of Treatment

Objective Explore type Ha Hangman fracture mechanics instability and treatment methodMethods Our department were2008,2-2011.1217cases according to Levine-Edwards points for type II a Hangman fractures and normal person20cases, Cervical hyperextension and over the nodule cortex flexion X ray measurements of the atlas to the axis spinous process two basis points on the leading edge extension cable to connect the distance,Fracture with normal flexion and hyperextension difference and change the value of X-rays in flexion, hyperextension of the differences compared to the distance in the type Ⅱa Hangman; By the posterior atlas hook, neck2vertebral pedicle screw, cervical vertebral body side piece of nail3great system fixation. The evaluation standard classification Frankel score neural function recovery. The method of using imaging evaluated bone healing.Result Type Ⅱa Hangman’s fracture in flexion, AO=13.24mm±0.477, normal flexion when the AO is5.28mm=0.526. comparison of the two significantly different (P<0.05); Type Ⅱa Hangman’s fracture in the hyperextended. the AO is8.12mm±303, normal hyperextended. AO=4.18mm±0.522. the two compared there is a significant difference (P<0.05); AO changes in the value on the X-rays in flexion and hyperextension fractures in type Ⅱa Hangman (5.04mm=0.261) and normal (1.1mm=0.07) significant difference (P<0.01);17cases have won6～36months of follow-up. The postoperation X line and hub of vertebral pedicle osseous healing, between vertebral body height and cervical stability are satisfied with reconstruction, cervical mobility obtain satisfactory restore. Did not happen connection rod and screw break or exit. The good clinical efficacy rate was94%.Conclusion Type Ⅱa Hangman fracture AO value in flexion than normal flexion significantly increased; AO change in flexion and hyperextension X-rays there are significant differences between the normal type Ⅱa Hangman fracture (P<0.01), show that the atlas posterior arch of axis spinous process exists to over-shift, indicating the existence of mechanical instability after atlantoaxiai column, AO value in flexion and hyperextension of the mean changes in the X-rays (5.04mm±0.261) may be used as column instability after fractures in type Ⅱa Hangman reference indicators, By the posterior atlas hook, neck2vertebral pedicle screw, cervical vertebral body side piece of nail3threat fixation svstem to receive a good curative effect..