Cross-Sectional Area of the Longus Colli and Cervical Degenerative Spondylolisthesis: A Retrospective Review Evaluating This Anatomic Consideration

Background: Limited literature is available to define the impact of the longus colli muscle, a deep flexor of the spine, on cervical spine stability despite its close proximity to the vertebrae. Aims and Objectives: The purpose of this study was to determine if longus colli cross-sectional area (CSA) is associated with the severity preoperative cervical degenerative spondylolisthesis. Materials and Methods: Patients undergoing elective anterior cervical discectomy and fusion (ACDF) for cervical spondylolisthesis between 2010-2021 were retrospectively identified. Longus colli cross-sectional areas (CSA) were measured from preoperative MRI images at the C5 level. Preoperative spondylolisthesis measurements were recorded with cervical radiographs. Patients were grouped by quartiles respectively according to longus colli CSAs. Statistical tests compared patient demographics, surgical characteristics, and surgical outcomes between groups. Multiple linear regression analysis was utilized to assess if longus colli CSA predicted cervical spondylolisthesis. Results: A total of 157 patients met inclusion criteria. Group 1 (first quartile) was the oldest (60.4 ± 12.0 years, P = 0.024) and was predominantly female (59.0%, P = 0.001). Group 1 also had the highest maximum spondylolisthesis (0.19 mm, P = 0.031) and highest proportion of grade 2 spondylolisthesis (23.1%, P = 0.003). On regression analysis, lowest quartile of longus colli CSA was an independent predictor of larger measured maximum spondylolisthesis (β: 0.04, P = 0.012). Conclusion: Smaller longus colli CSA is independently associated with a higher grade and degree of preoperative cervical spondylolisthesis, but this finding does not result in adverse postsurgical outcomes

Sagittal Alignment Differences on the Operating Room Table Compared to Preoperative and Postoperative Imaging in Anterior Cervical Discectomy and Fusion

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 \u3c 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 \u3c 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