G. E. T., a man, aged 43, was admitted to the Evanston Hospital on Sept. 9, 1934, immediately after he had been thrown from a horse, striking directly on the left occipitoparietal region of his head. X-ray examination at this time showed no fracture of the cervical spine, but a slight forward dislocation of the sixth cervical vertebra on the seventh. The dislocation was readily reduced by placing the neck in extension and exerting from 3 to 4 pounds of traction on the head. He was discharged from the hospital September 20, wearing an aluminum neck-brace, which supported the head and held the neck in extension. Reexamination of the neck by x-rays three weeks later showed that the luxation had recurred and had even increased, and the patient was having considerable pain in the neck at this time. He was readmitted to the hospital October 18.
Ryerson EW, Christopher F. DISLOCATION OF CERVICAL VERTEBRAE: OPERATIVE CORRECTION. JAMA. 1937;108(6):468-470. doi:10.1001/jama.1937.92780060001009