Comparing the trajectory accuracy of pedicle screws placed with a free-hand technique and a three-dimensional computed tomography-assisted navigation system in spine surgery: A retrospective study

Abstract

Objective: We evaluated a free-hand technique and a three-di-mensional computerized tomography (3D-CT)-assisted naviga-tion technique, which are pedicle screw placement techniques used in spinal surgery, regarding screw placement and reliability.Material and Method: A total of 1664 screws in 73 patients with spinal deformities who underwent spinal instrumentation using pedicle screws were evaluated in this study. Forty patients were in the free-hand technique group, and 33 patients were in the 3D-CT-assisted navigation technique group. The placement and reliability of pedicle screws in all patients were evaluated using the Gertzbein-Robbins classification using CT images taken in the postoperative period.Result: There were no significant differences found regarding age, body mass index (BMI), sex (female or male), or deformity (scoliosis or kyphosis) (p>0.05). When the pedicle screws were evaluated in terms of transverse penetration, the 3D-CT-assisted navigation technique was determined Grade A (89.6%), as was the free-hand technique (76.5%), but the 3D-CT-assisted navi-gation technique was statistically more reliable (p<0.001). When the pedicle screws were evaluated in terms of anterior penetra-tion, both the 3D-CT-assisted navigation technique (92.5%) and the free-hand technique (82.9%) were determined Grade A, but the 3D-CT-assisted navigation technique was statistically more reliable (p<0.001).Conclusion: According to our studys results, the 3D-CT-assist-ed navigation technique is more reliable than the free-hand technique in surgeries involving spine deformities for pedicle screw insertion.