Sagittal alignment differences on the operating room table compared to preoperative and postoperative imaging in anterior cervical discectomy and fusion

Mark J Lambrechts; Gregory R Toci; Brian A Karamian; Zachary Kozick; John Prodoehl; David Reiter; Rahul Muchintala; Eric Tecce; Alexander Vaccaro Jr; Patrick O'Connor; Amit Syal; Dominic Lambo; Jose A Canseco; I David Kaye; Barrett I Woods; Alan S Hilibrand; Christopher K Kepler; Alexander R Vaccaro; Gregory D Schroeder

doi:10.4103/jcvjs.jcvjs_100_22

Sagittal alignment differences on the operating room table compared to preoperative and postoperative imaging in anterior cervical discectomy and fusion

J Craniovertebr Junction Spine. 2022 Oct-Dec;13(4):415-420. doi: 10.4103/jcvjs.jcvjs_100_22. Epub 2022 Dec 7.

Authors

Mark J Lambrechts¹, Gregory R Toci¹, Brian A Karamian¹, Zachary Kozick¹, John Prodoehl¹, David Reiter¹, Rahul Muchintala¹, Eric Tecce¹, Alexander Vaccaro Jr¹, Patrick O'Connor¹, Amit Syal¹, Dominic Lambo¹, Jose A Canseco¹, I David Kaye¹, Barrett I Woods¹, Alan S Hilibrand¹, Christopher K Kepler¹, Alexander R Vaccaro¹, Gregory D Schroeder¹

Affiliation

¹ Department of Orthopaedic Surgery, Rothman Institute, Thomas Jefferson University, Philadelphia, PA, USA.

Abstract

Study design: The study design used was a retrospective cohort.

Objective: The objective of this study is to determine if intraoperative improvements in sagittal alignment on the operating table persisted on postoperative standing radiographs.

Summary of background data: Cervical sagittal alignment may be correlated to postoperative outcomes. Since anterior cervical discectomy and fusions (ACDFs) can restore some cervical lordosis through intervertebral grafts/cages, it is important to understand if intraoperative radiographic measurements correlate with persistent postoperative radiographic changes.

Materials and methods: Patients undergoing elective primary ACDF were screened for the presence of lateral cervical radiographs preoperatively, intraoperatively, and postoperatively. Patients were excluded if their first postoperative radiograph was more than 3 months following the procedure or if cervical lordosis was not able to be measured at each time point. Paired t-tests were utilized to compare differences in measurements between time points. Statistical significance was set at P < 0.05.

Results: Of 46 included patients, 26 (56.5%) were female, and the mean age was 55.2 ± 11.6 years. C0-C2 lordosis significantly increased from the preoperative to intraoperative time point (delta [Δ] = 4.49, P = 0.029) and significantly decreased from the intraoperative to postoperative time period (Δ = -6.57, P < 0.001), but this resulted in no significant preoperative to postoperative change (Δ = -2.08, P = 0.096). C2 slope decreased from the preoperative to the intraoperative time point (Δ = -3.84, P = 0.043) and significantly increased from the intraoperative to the postoperative time point (Δ = 3.68, P = 0.047), which also resulted in no net change in alignment between the preoperative and postoperative periods (Δ = -0.16, P = 0.848). There was no significant difference in the C2-C7 SVA from the preoperative to intraoperative (Δ = 0.85, P = 0.724) or intraoperative to postoperative periods (Δ = 2.04, P = 0.401); however, the C2-C7 SVA significantly increased from the preoperative to postoperative period (Δ = 2.88, P = 0.006).

Conclusions: Intraoperative positioning predominantly affects the mobile upper cervical spine, particularly C0-C2 lordosis and C2 slope, but these changes do not persist postoperatively.

Keywords: Alignment; anterior cervical discectomy and fusion; intraoperative positioning; lordosis.