The accuracy of C-ARM in evaluating pelvic incidence and lumbar lordosis during surgery compared with EOS radiography after lumbar fixation.

Background: Achieving the global spinal alignment, especially the pelvis, in spine surgeries is considered the most important factor in the success of these surgeries, which requires an accurate evaluation of the correction angles measured during surgery. This study aimed to evaluate the accuracy of the mobile C-arm X-ray machine (C-ARM) for measuring lumbar lordosis (LL) and pelvic incidence (PI) parameters during lumbar fixation.

Methods: In this prospective study, 59 lumbar fixation candidates who underwent surgery between 2020 and 2022 at our medical center, were examined. PI and LL parameters were measured at the fusion site with fluoroscopy, during surgery with C-ARM, and after surgery with EOS locally.

Results: The mean age was 54.69 ± 17.62 years. 42 (71.2%) were female. The mean PI based on intraoperative C-ARM and post-surgery EOS findings were 54.57 ± 11.19 and 54.83 ± 11.17, respectively, which this difference was not statistically significant (P = 0.9). The mean LL estimate based on C-ARM and EOS findings was similar (P: 0.44).A significant positive linear correlation was observed for the mean PI (r: 0.97, p: 0.001) and LL (r: 0.99, p: 0.001).

Conclusion: The mean PI and LL angle during operation (measured with C-ARM) was similar to the mean of these parameters in EOS imaging findings after surgery. C-ARM can be used as a convenient device in the operating room with high precision to measure PI and LL values in spine surgeries.