Free-Hand Pedicle Screw Placement Using a Ball Tip Widening Technique for Small Pedicles

The purpose of this study was to assess the accuracy and validity of the "ball tip widening technique." We designed a retrospective analysis of 212 pedicle screws inserted in correction surgery for pediatric scoliosis, using posterior spinal instrumentation and fusion with pedicle screws at Seoul National University Bundang Hospital between July and August of 2021. The accuracy of pedicle screw placement was then classified using intraoperative computed tomography (CT; O-arm). Intraoperative CT revealed that 86.8% of pedicle screws (184 / 212) were placed in pedicle. The ball tip widening technique introduced in this study can enhance the accuracy of screw insertion into small pedicles. Furthermore, this technique may also be applied to lumbar surgery for degenerative conditions in the future.