Traction load,tong position,and head support significantly influence cervical spine loading during traction

Abstract

Some cervical dislocation injuries may be acutely treated with traction via Gardner-Wells tongs, which are attached to the skull via two pins. While a variety of techniques have been proposed and utilized in the literature and clinical practice to use the tongs, these techniques have not been methodically studied to confirm how they transmit loads to the cervical spine. The current study investigated the mechanical effect of different traction techniques in a laboratory setting. A 50th male Hybrid anthropomorphic test device was used as a human surrogate to represent an average male in height and weight was modified to represent a patient with a unilateral facet dislocation injury. Electronic sensors at the atlanto-occipital joint recorded the loading delivered to the superior cervical spine by traction loading. Combinations of the following variables were evaluated as traction loads were progressively increased to one-third of body weight: tong pin position in the skull (anterior–posterior and superior–inferior to the recommended neutral position), traction cable angle in the sagittal plane (elevated, horizontal, declined), and presence or absence of an occipital support. Analysis of the cervical axial traction loads showed that the only significant predictor of cervical tension was the magnitude of the traction load. Anterior–posterior changes in the pin positions in the skull significantly influenced the cervical flexion–extension moment and anterior-posterior (AP) shear. The data show that a combined cervical tension, flexion moment, and anterior shear force can be achieved with posteriorly biased pins and a bolster behind the head. Increasing the angle of traction cable increased the cervical flexion moment and anterior shear force. The following variables should be carefully considered when applying cervical traction since they significantly affect cervical loading: magnitude of the hanging traction load, anterior–posterior pin position, use of an occipital bolster, and traction load angle.