Are Self-drilling, Self-tapping Screws Effective in Anterior Cervical Fusion Surgery? A Single Surgeon’s Experience in 50 Consecutive Patients

Introduction: The use of plating and screw design in anterior cervical discectomy and fusion (ACDF) has evolved to improve fusion stability and enhance patient outcomes. Of note, some argue that pre-tapping, and not using these self-tapping, self-drilling screws, is the best option in these cases. Hence, the objective of this study is to evaluate the outcomes and complications with self-drilling, self-tapping screws and evaluate their efficacy in maintaining instrumentation position after ACDF with plating.

Methods: Patients who underwent ACDF with plating and self-drilling, self-tapping screws from February 2021 to May 2023 were consecutively included. Demographic, radiographic, intraoperative, and postoperative data were collected. Odds ratios (ORs) were also utilized to determine factors associated with abnormal C2-C7 Cobb angles and C2-C7 sagittal vertical axes (SVAs) postoperatively.

Results: A total of 50 patients (26M, 24F, mean age: 56.7 ± 10.4) operated on at an average of 1.8 levels were included. At final postoperative radiographic follow-up, the C2-C7 Cobb angle increased by 21.03%, with the C2-C7 SVA increasing by 3.25%. OR assessment found an association with the American Society of Anesthesiologists (ASA) physical status classification score of ≥ 3 and abnormal postoperative C2-C7 SVA (95% CI: 0.033 to 0.937, p=0.042). Longer operative times (≥91.5 minutes) were less likely to be associated with abnormal postoperative C2-C7 Cobb angles when compared to shorter operative times (0.175, 95% CI: 0.032 to 0.952, p=0.044). No fixation system complications or evidence of radiographic or clinical pseudoarthrosis were noted.

Conclusion : Patients undergoing ACDF with self-drilling, self-tapping screws to fixate the plate had excellent postoperative outcomes. No evidence of instrumentation complications, including pseudoarthrosis, were evidenced. This cohort demonstrates the safety of ACDF with this screw design. Contrary to popular belief, separate pre-tapping or pre-drilling is not necessary.