Accuracy and Outcomes of Freehand Thoracic Pedicle Screw Placement using Qi’s Technique

Abstract

Objective: Many authors have proposed a variety of strategies for freehand thoracic pedicle screw (PS) placement based on identifying ideal entry points and trajectories in the transverse and sagittal planes. This study aimed to assess the accuracy and safety of using a landmark proposed by Qi et al., for determining the entry point and trajectory for freehand thoracic PS placement. Material and Methods: A total of 59 consecutive adult patients who underwent thoracic (T1-T12) PS fixation using Qi’s landmark were enrolled in this retrospective study. Demographic and diagnostic information, adverse events, and postoperative pedicle violation grading were all recorded for analysis. Results: A total of 398 thoracic pedicle screw insertions were analyzed. There were no cases of postoperative neurological deterioration, however two patients required revision surgery to remove a misplaced screws at T6 and T7 due to significant medial wall violation. A total of 360 PSs (90.5%) and 28 PSs (7.0%) were categorized as having high accuracy and low accuracy, respectively. The remaining 10 PSs (2.5%) in the lateral cortex violation group were considered clinically acceptable due to their position in the rib-pedicle unit. The most common location for misplaced screws was the T4 to T8 vertebral region. Conclusion: In terms of accuracy and safety, our findings support using Qi’s technique for freehand thoracic PS placement. The rate of screw misplacement was comparable to that of other techniques. Surgeons should be familiar with the unique anatomy of the mid-thoracic region because it constitutes the most common site of misplaced screws.