A comparison of the biomechanical performance of anterior cervical discectomy and fusion plate constructs in a validated biomimetic spine model after pilot hole creation using an awl versus fluted hand drill

- Austin Allen , Andrew Rees, Rebecca DeCarlo, Michael Bohl


Anterior cervical discectomy and fusion (ACDF) is a commonly performed surgical procedure. Many technological improvements have been pursued in recent years to strengthen the construct and decrease the probability of hardware failure. However, the impact of various methods of pilot hole creation on biomechanical performance has not been well explored. In this study, we compared how pilot holes created with an awl versus fluted hand drill impacted the biomechanical performance of ACDF hardware constructs. This work was performed at the Carolina Neurosurgery and Spine Associates (CNSA) biomechanics lab using a validated biomimetic model 3D printed using acrylonitrile butadiene styrene filament based on a high-resolution CT scan of a normal cervical vertebrae. The maximum pullout strength, strain, and stiffness were measured in 10 models with pilot holes prepared using a hand drill, and 10 models with pilot holes prepared using an awl. There was a trend toward greater mean maximum pullout force in the awl group (807.8 N) than the hand drill group (770.2 N) (p = 0.054), although it did not reach statistical significance. There was no significant difference in strain between the awl group (1952 Nmm) as compared to the hand drill group (1724 Nmm) (p = 0.099), and no difference in stiffness between the awl group (268.9 Nmm) and hand drill group (273.6 Nmm) (p = 0.76). Results from this study suggest that preparing pilot holes with an awl may yield ACDF constructs with greater pullout strength; however, further investigation is warranted to better understand this trend.