Comparison of the pedicle screws placement between electronic conductivity device and normal pedicle finder in posterior surgery of scoliosis.

STUDY DESIGN: Prospective randomized clinical trial. OBJECTIVE: To compare the accuracy and time using of pedicle screw placement between electronic conductivity device (ECD) and normal pedicle finder (NPF) in posterior surgery of scoliosis, through a randomized clinical trial. SUMMARY OF BACKGROUND DATA: Pedicle screw insertion for scoliosis correction can be associated with increased pedicle perforations. The malposition rates using various techniques in different region of the spine have been reported to occur with a frequency of 3.3%-43%. An ECD has been reported in spine surgeries, but its accuracy and surgical time comparing with NPF in the presence of scoliosis has not been reported. METHODS: The 42 patients of adolescent idiopathic scoliosis with average major Cobb angle of 55.3±7 degrees (range, 45-78 degrees), who received posterior correction surgeries using pedicle screws system only were divided into 2 groups by random: group NPF (22 patients); and group ECD (20 patients). NPF group had 332 screws and ECD group had 362 screws. The 2 groups were compared for accuracy of screw placement, time for screw insertion, and the number of times the C-arm had to be brought into the field. RESULTS: There were 47 (14.2%) pedicle perforation in the NPF group as compared with only 15 (4.1%) in the ECD group (P<0.001). Although in different region of the spine, screw accuracy showed discrepant statistical result, with upper (T1-T3), middle (T4-T7), and lower thoracic (T8-T10) comparison showing significant statistical difference (P=0.010, 0.001, and 0.041, respectively) and thoracolumbar (T11-L2) and lower lumbar (L3-L5) comparison showing no significant statistical difference (P=0.278 and 0.292, respectively). Average screw insertion time in the NPF group was 241±61 seconds compared with 204±33 seconds in the ECD group (P=0.009). The C-arm had to be moved into the operation field on an average of 1.59±0.67 times in the NPF group compared with 1.20±0.52 in the ECD group (P=0.040). CONCLUSIONS: ECD increases pedicle screw accuracy, especially in T1-T10, and reduces insertion time and radiation in posterior adolescent idiopathic scoliosis.