Purpose: The purpose of this retrospective study was to measure changes between pre and post-operative sagittal cervical parameters using X-Rays of patients who underwent cervical spine surgery at UCLA between 2013 and 2017.
Methods: C2-7 lordosis, sagittal vertical axis, T1 slope, and C2-occiput angle were measured from pre- and post-operative X-Rays using the SurgiMap software suite. Pre-operative diagnosis, surgical approach (anterior or posterior), number of segments operated upon, age, gender and race were also tabulated for each patient.
Results: Among the 105 patients analyzed, C2-7 lordosis, T1 slope and C2-Occiput angle measurements did not change statistically significantly between pre and post-operative X-rays as assessed by paired t-tests with α = 0.1292, 0.2168, and 0.4542 respectively. Change in mean sagittal vertical axis was statistically significant at α = 0.01. The mean increase was 2.56mm after surgery.
Conclusions: Surgery does affect sagittal cervical parameters, assessable on X-Ray. Within this cohort, only sagittal vertical axis changed significantly. Future data collection and analysis may uncover additional patterns of change. Some of these parameters are likely to be important in classifying patients who will develop adjacent segment disease (ASD) post operatively, as well as to identify new radiographic markers of ASD. A large prospective study would help control for the great variability in imaging modality used pre and post operatively, substantially expanding the population of patients available for measurement and comparison. Finally, automation could make this practice much more accurate, precise, and timely, maximizing clinical applicability.