Written by Laura Dyrda
A new study published in the Journal of Spinal Disorders and Techniques examines whether CT scans overestimated fusion rates after anterior cervical discectomy and fusion.
The researchers examined 22 patients after ACDF — cortical allograft with anterior plates — with 34 levels fused. The patients had CT scans and dynamic X-rays at three, six and 12 months after surgery. There were four surgeons blinded to the time the images were taken determining fusion status. 
Here are six findings from the study:
1. At each time point, the CT scans showed higher rates of fusion than the X-ray:
• Three months: 26 percent for X-ray, 79 percent for CT scan
• Six months: 41 percent for X-ray, 79 percent for CT scan
• 12 months: 65 percent for X-ray, 91 percent for CT scan
2. The predicted fusion rate at each time point was significantly different and at three months, 41 percent of the levels the CT scan criteria determined were fused demonstrated greater than 1 mm motion on the dynamic X-rays.