Accuracy and Safety of a Triad-Dependent Technique for Subaxial Cervical Pedicle Screw Placement: A Prospective Cohort Study.

Abstract

Study DesignProspective single-arm cohort study.ObjectivesCervical pedicle screws (CPS) offer superior biomechanical stability compared with lateral mass screws. However, their widespread adoption is constrained by narrow pedicle safety margins and the potential risk of neurovascular injury. This study aimed to describe the rationale of a novel triad-dependent technique (TDT) for subaxial CPS placement and to evaluate its accuracy and safety.MethodsBetween May 2023 and April 2025, 63 consecutive patients undergoing posterior subaxial (C3-C6) cervical instrumentation at our institution were screened for eligibility. CPS were inserted using the TDT, which integrates individualized morphometric preoperative planning, intraoperative fluoroscopic guidance, and continuous tactile monitoring via mini-laminotomy. Postoperative CT was used to assess screw accuracy using the 2-mm breach classification. Multinomial logistic regression was performed to identify risk factors for breach.ResultsA total of 204 CPS were inserted in 41 patients. No breach was observed in 174 screws (85.3%), while 30 screws (14.7%) demonstrated breach, including 18 medial and 12 lateral violations. No neurovascular complications were observed in this cohort. Pedicle diameter <4 mm significantly increased the risk of both medial and lateral breach, while medial wall thickness showed direction-specific effects on breach risk.ConclusionsThe TDT demonstrates the feasibility of accurate and safe subaxial CPS placement. By integrating individualized morphometric planning with fluoroscopic and tactile safeguards, TDT effectively mitigates both medial and lateral breach risks and may expand the safe application of CPS fixation.