Hangman's fracture: A biomechanical comparison of stabilization techniques

Document Type

Article

Abstract

STUDY DESIGN. In vitro biomechanical flexibility experiment studying 5 sequential conditions. OBJECTIVE. To determine the biomechanical differences among 3 fixation techniques after a simulated hangman's fracture. SUMMARY OF BACKGROUND DATA. Type II hangman's fractures are often treated surgically with a C2-C3 anterior cervical discectomy, fusion, and plating. Other techniques include direct fixation with C2 pars interarticularis screws or posterior C2-C3 fixation connecting C2 pars screws to C3 lateral mass screws. METHODS. Seven cadaveric specimens (Oc-C4) were tested intact, after a simulated hangman's fracture, and after each fixation technique. Flexion, extension, lateral bending, and axial rotation were induced using nonconstraining torques while recording angular motions stereophotogrammetrically. RESULTS. Direct screw fixation reduced motion an average of 61% ± 13% during lateral bending and axial rotation compared to the injured state (P < 0.007). However, instability remained during flexion and extension. Posterior C2-C3 rod fixation provided significantly greater rigidity than anterior plate fixation during lateral bending (P < 0.008) and axial rotation (P < 0.04). CONCLUSIONS. Direct fixation of the pars ineffectively limits flexion and extension after a Type II hangman's fracture. If pars screw fixation can be achieved, posterior C2-C3 fixation more effectively stabilizes a hangman's fracture than anterior cervical plating. © 2007 Lippincott Williams & Wilkins, Inc.

Keywords

Biomechanics, Cervical spine, Hangman'sfracture, Pars, Pedicle, Spinalinstrumentation

Publication Date

1-1-2007

Publication Title

Spine

ISSN

03622436

E-ISSN

15281159

Volume

32

Issue

2

First Page

182

Last Page

187

PubMed ID

17224812

Digital Object Identifier (DOI)

10.1097/01.brs.0000251917.83529.0b

This document is currently not available here.

Share

COinS