Construction and Accuracy Assessment of Patient-Specific Biocompatible Drill Template for Cervical Anterior Transpedicular Screw (ATPS) Insertion: An In Vitro Study
Figure 5
Illustration of grades of ATPS positions in cervical pedicle.
Grade 1: Screw positioned at the center of the pedicle. Grade 2: Less than one-third of the screw cross-section (≤1.2 mm with a 3.5-mm diameter screw) penetrating the cortex. Grade 3: Between one-third and one-half of the screw cross-section penetrating the cortex (or deviation <2 mm). Grade 4: More than one-half of the screw cross-section penetrating the cortex (or deviation ≥2 mm). Grade 5: Deviation equal or greater than the screw diameter.