Double noncontiguous cervical spinal injuries.

BACKGROUND: Double noncontiguous spinal injuries in the same patient, the first at the cervical level and the second at the thoracic or thoracolumbar level are not uncommon. On the other hand the incidence of double noncontiguous cervical injuries in low and these injuries imply complex mechanisms. This study investigates the cases of double noncontiguous cervical lesions in 342 cases of acute cervical injuries.

METHOD: An analysis of 342 patients with cervical injuries found 67 multiple cervical injuries and only 11 cases of double noncontiguous cervical lesions.

FINDINGS AND INTERPRETATION: Double noncontiguous cervical injuries have a frequency of 3.2% in this study and in three cases there were pre-existing benign cervical lesions. A possible spinal biomechanical behaviour during injury can be that the first lesion appears because of the traumatic impact and there is a uniform transmission of the remaining traumatic strain all along the spine. It seems that the propagated force finds a spinal zone where the spinal resistance is diminished and the second spinal lesion can occur. Spinal vulnerability for the second lesion in the same trauma can be caused by a pre-existing benign spinal lesion or by a biomechanical discontinuity because of a particular posture at the traumatic moment. The second lesion in double noncontiguous cervical lesions can appear through a single great impact in pre-existing lesions, double impacts at the same time with injuries at two cervical levels or repeated cervical impacts in very quick succession in the same trauma.