Accuracy and risk factors of Magerl screw placement in robot-assisted atlantoaxial surgery: A case series study

BackgroundTo assess the accuracy of robot-assisted Magerl screw placement and explore the factors affecting the accuracy.MethodsA retrospective analysis of patients who underwent robot-assisted Magerl screw placement was performed. The accuracy of Magerl screw placement was evaluated according to the Gertzbein and Robbins scale.Results47 Magerl screws were placed in 24 consecutive patients. 32 Magerl screws were narrower than the C2 isthmus height and 26 of them were grade A. 15 Magerl screws were wider than the C2 isthmus height and all of them were grade B. Temporary fixation after decompression and a smaller difference between the C2 isthmus height and screw diameter were associated with a higher probability of cortical breach.ConclusionThe accuracy of robot-assisted Magerl screw placement was excellent. Temporary fixation after decompression and a smaller difference between the C2 isthmus height and screw diameter increased the risk of cortical breach.