Accuracy and safety assessment of subaxial cervical pedicle screw instrumentation: a systematic review.

Background context: Given increasing use of both cervical pedicle screw (CPS) fixation in the subaxial cervical spine (C3-C7) and emerging navigation technologies, a quantitative profile of safety and accuracy remains wanting. Compared with lateral mass instrumentation of this region, CPS fixation shows superior biomechanical properties but poses higher risk of complications because of the narrow cervical pedicle width and proximity to neurovascular structures.

Purpose: This systematic review quantifies the accuracy and safety of all types of subaxial CPS insertion, with or without navigation or template-based methods, to weigh the strengths and limitations of each technique.

Study design: Systematic review according to PRISMA guidelines.

Patient sample: Patients who underwent CPS instrumentation since its introduction.

Outcome measures: Primary and secondary outcomes in our review included pedicle screw breach in the subaxial cervical spine determined on intra- or postoperative imaging, and screw-related operative complications, respectively.

Methods: Following the PRISMA guidelines, our literature search of PubMed, Cochrane, and Scopus databases identified 3,312 clinical studies (1980--2024) using subaxial CPS that assessed for screw accuracy. After full-text analysis, data extracted included number of CPS, level of placement, number of patients, indications, insertion techniques, accuracy assessment method, classification of accuracy, breach rate, complication rate, and study origin.

Results: The 73 studies included in final analysis from Asia (80%), Europe (12%) and North America (8%) yielded 14,118 CPS in 3,342 patients (1999-2024). Accuracy rates were 85.3% for 10,108 CPS placed with nonnavigated techniques (free-hand and fluoroscopy), 82.7% for 3,067 with navigation techniques, and 96.3% for 943 CPS placed using 3D templates. Complication rates were 1.1%, 2.1%, and zero, respectively.

Conclusion: Our comprehensive review of more than 14,000 subaxial CPSs inserted found rates of high 84% overall accuracy and low 1.2% perioperative complications (ie, attributed to a misplaced screw). With biomechanical advantages superior to lateral mass screws, our quantitative findings support consideration for CPS instrumentation in select patients by experienced surgeons.