A Novel Free-Hand Technique of Pedicle Screw Placement in the Lumbar Spine: Accuracy Evaluation and Preliminary Clinical Results

Abstract

Abstract Objective To propose a novel free-hand pedicle screw placement technique in the lumbar spine and investigate its accuracy and safety in clinical practice. Methods 110 patients with herniation of a single lumbar disc were recruited for our study. All patients were consistently treated with posterior discectomy, interbody fusion, and transpedicular internal fixation. For 54 patients in the observation group, the pedicle screws were placed with our technique, which is located at 4 mm below the superior edge of the transverse process in line with the lateral margin of the superior articular process. For 56 patients in the control group, pedicle screws were placed according to the traditional crista lambdoidalis method. Comparisons were made in terms of the operation time, blood loss, time for exposure, the accuracy of placement, and postoperative complications. In addition, we prospectively applied our method to 64 patients with indistinguishable crista lambdoidalis and evaluated the accuracy of screw placement and clinical outcomes. Results There was no significant difference in intraoperative bleeding, accuracy of placement, and postoperative complications between our technique and the traditional crista lambdoidalis method (P > 0.05). However, the exposure time before screw placement (12.8 ± 0.3 vs 17.4 ± 0.3, p = 0.001) and the total surgery time (97.2 ± 1.9 vs 102.3 ± 0.9, p = 0.020) were significantly shortened with our method. Additionally, in cases of indistinguishable crista lambdoidalis, our technique showed satisfying accuracy, with 97.6% screws placed in appropriate trajectory on the first attempt and all screws eventually positioned in the safe zone according to the Gertzbein Robbins grading. All patients experienced steady improvement after surgery, as assessed with the visual analog pain scale and the Japanese Orthopaedic Association (JOA) score. Conclusion This study highlights a safe and effective technique for pedicle screw placement in the lumbar spine, which is particularly useful in cases of vertebral fracture and severe hyperplasia or degeneration of the facet joint.