Randomized Clinical Study to Compare the Accuracy of Navigated and Non-Navigated and Non-Navigated Thoracic Pedicle Screws in Deformity Correction Surgeries

Methods: Thirty three patients (27 scoliosis and 6 kyphosis) were randomly allocated to navigation group (17 patients and 242 screws) and non-navigation group (16 patients and 236 screws). Cobb's angle was 58.4 ±8 (range 50 -80 ) and kyphotic angle was 54.6 ±4 (range 51 -76 ). Accuracy was analysed on post-operative CT scans by two independent observers blinded to the study.

Results: The non-navigation group had an average of 5.2±2.8 (3-13) exposures per screw taking about 4.61±1.05min (1.8-6.5min) per screw. The C-arm had to be moved in to the operation field at an average of 4±3 (1-11) times per screw. The navigation group had an average insertion time (including average data acquisition time per screw) of 2.37±0.72min per screw (range 1.16-4.5 min). The average data acquisition time in the ten patients was 24.6±6.3min (range 16-33 min). There were fifty four (23%) pedicle breaches in the non-navigation group as compared to only five (2%) in the navigation group and this was statistically significant (p<0 .001). Mid-thoracic region had the highest rate of pedicle breaches (49%). Thirty eight screws (16%) in non-navigation group penetrated anterior or lateral cortex compared to two (0.8%) navigation group. There were higher noticed kyphosis (27%) scoliosis (11%).

Conclusions: Iso-C based navigation surgery in thoracic deformity correction surgeries using pedicle screw instrumentation reduces surgical time, radiation exposure time, decreases pedicle perforations, increases depth perception, enhances accuracy, and also the surgeon's confidence to a large extent.