Are C2 pars-pedicle screws alone for type II Hangman's fracture overrated?

The recent trend for treatment of certain cases of type II Hangman's fracture has been towards motion preserving surgery. This is claimed to be achieved with placement of pedicle screws across the fracture fragments. However, the long term outcome in clinical scenario is not yet clear, neither are the factors determining suitability of such a technique.

We have retrospectively analyzed the results of 11 patients of type II Hangman's fracture, according to the extent of translation. Nine patients underwent stabilization of fracture with C2 pedicle screws and 2 were managed with halo immobilization. The conservative management failed in one and this patient underwent internal fixation using pars-pedicle screw as well. The long term clinical and radiological (CT and dynamic X-rays) outcome was analyzed.

All patients including the one with halo immobilization, showed solid fusion across the fracture fragments. With the exception of one patient none had any clinical symptoms. This lone patient complained of restricted neck movements. Three different types of radiological results were observed. Two patients with translation >8mm showed C2-3 body fusion. Three of 6 patients with minimal translational (3-4mm) showed facet fusion. Three patients with moderate translational dislocation (4.5-5.5mm) showed persisting C2-3 angular instability.

The C2 pedicle screw is a good technique for osteosynthesis. However, the claimed long term advantage of motion segment preservation with this technique remains doubtful. It may be suitable for those fractures with minimal translation (<4mm), where the superiority of surgery, itself, over external immobilization is questionable. C2-3 fusion is preferable for those fractures with translation >4mm as these are unstable and C2 pedicle screws alone are likely to have less desirable results.