Clinical relevance of multislice CT of the spine after osteosynthesis

Purpose: To examine the clinical relevance of multislice CT (MSCT) scans in postoperative checks of the spine after osteosynthesis. Material and Methods: The results of x-rays (apical lateral) in 30 patients having spinal surgery involving osteosynthesis (5 x metastasis, 20 x fractures, 3 x spondylolisthesis, 2 x scoliosis) were correlated to those of MSCT (140 kV, 200 mAs, collimation 4 x 1 mm, pitch 0.75; VolumeZoom, Siemens, Erlangen, Germany) with multiplanar reconstruction. Two radiologists independently checked the conventional x-ray and multislice CT scans for anatomical positioning, damage of osteosynthetic material, and intraspinal dislocation of bone fragments. Results: By correlating conventional spinal x-rays with MSCT, additional diagnostic information was gained. In 9 of 30 patients MSCT revealed the extraosseal location of a screw tip (x-ray, 5/30), in 8/30 patients a narrowing of the spinal canal by osteosynthetic material was detected in MSCT (x-ray, 4/30), in 2/30 patients osteal fragments were detected in the vertebral canal by MSCT (x-ray, 0/30). In MSCT and in conventional x-ray a fracture of the osteosynthesis was correctly diagnosed in 3 patients. One patient underwent corrective surgery for dislocated osteosynthetic material, which was solely diagnosed with MSCT. Conclusion: Due to the high degree of additional diagnostic information MSCT seems to be the method of choice for postoperative spinal surgery involving osteosynthesis.