Option of anterior or posterior approach for unstable Hangman fracture

English Keywords:Hangman fracture  Instability  Disc-ligamentous  Complex

English Abstract:

  【Abstract】 Objectives： To investigate the risk factors and clinical outcome of anterior or posterior approaches for unstable hangman fracture. Methods： 65 patients with hangman fracture from May 2004 to May 2011 in our hospital were reviewed retrospectively. Preoperative and intraoperative skull traction was applied and C-arm fluroscopy was used to evaluate the condition of C2-C3 disc and paravertebral ligaments. The fracture morphology of the involved cervical vertebrae was evaluated by X-rays, computed tomography and magnetic resonance images. Patients with the following conditions underwent anterior approach: C2-C3 disc space increase, comminuted fracture of pars interarticularis of C2, narrowed C2 pedicle, high notch of vertebral arteries of C2, C3 body fracture and C3 pedicle deformity. Patients without C2-C3 disc space increase or irreducible interlocking of posterior facets of C2-C3, or pedicle fracture of C3 underwent posterior approach. The clinical outcomes and rediograph results were reviewed. Results： Except for C2 pars fracture combined with C2/3 instability, severe injury and deformity included: completely rupture of C2-C3 intervertebral discs and ligamentous structure in 9 cases, narrowed C2 pedicle in 1 case, high notch of vertebral arteries of C2 in 2 cases, comminuted fracture of pars interarticularis of C2 in 3 cases, C3 body fracture in 3 cases, C3 pedicle fracture in 3 cases, C3 pedicle narrowing in 2 cases, and C3 pedicle sclerosis in 2 cases. Fifteen patients underwent anterior surgery, which included intervertebral disc space increase in 3 cases, fracture of C2 pars interarticularis in 2 cases, C3 body fracture and C3 pedicle narrowing in 1 case, C3 body fracture and reduced interlocking of posterior facets of C2-C3 in 1 case, C2 high notch of vertebral arteries in 1 case. Seven other cases without C2-C3 disc space increase also underwent anterior surgery, which included narrowing of C2 pedicle in 1 case, fracture of C3 body and reduced interlocking of posterior facets in 1 case, uncertain injuries of C2-C3 intervertebral discs and ligamentous structure in 1 case, C3 pedicle sclerosis in 2 cases, C2 high notch of vertebral arteries and C3 pedicle narrowing in 1 case, comminuted fracture of C2 pars interarticularis and irreducible facets interlocking in 1 case. Fifty patients received posterior surgery: no disc space increase in 44 cases, disc increase in 1 case, failure of reduction of C2-C3 in 2 cases, fracture of C3 pedicle in 3 cases. Anterior and posterior approach was noted 7 and 8 complications respectively. Conclusions： Unstable Hangman fracture complicated with C2/3 dislocation, injury to disc-ligament complex, complicated fracture and deformity can be used to guide the surgical approach.