A Comparison of Three Different Positioning Techniques on Surgical Corrections and Postoperative Alignment in Cervical Spinal Deformity (CD) Surgery

Kyle W. Morse, MD; Renaud Lafage, MS; Peter Passias, MD; Christopher P. Ames, MD; Robert Hart, MD; Christopher I. Shaffrey, MD; Gregory Mundis, MD; Themistocles Protopsaltis, MD; Munish Gupta, MD; Eric Klineberg, MD; Doug Burton, MD; Virginie Lafage, PhD; Han Jo. Kim, MD

Disclosures

Spine. 2021;46(9):567-570. 

In This Article

Discussion

The purpose of this study was to examine the differences in sagittal alignment correction between three positioning methods in cervical spinal deformity surgery. We found significant improvements in postoperative alignment across the entire cohort despite the positioning method utilized (Table 4) with the majority of segmental correction occurring at C4–5–6. These results confirm our hypothesis that positioning technique did not affect postoperative sagittal correction for patients with sagittal deformity with the exception of bivector traction providing segmental correction at the cervicothoracic junction (P < 0.027).

Surgical positioning must allow adequate anatomic exposure, ergonomic favorability for the surgeon, the ability to visualize the spine fluoroscopically, and the prevention of positioning related injuries to the patient. CD surgery can create intraoperative instability as osteotomies are performed and control is required to prevent injury to the spinal cord.[4,5] Karikari et al[6] used bivector traction by adapting Gardner-Wells tongs during posterior cervical fusion. This positioning technique has several reported advantages. The patient's head can be maintained in flexion during exposure, decompression, facet decortication, and screw placement to allow for easier decortication and oblique screw trajectories and avoids excessive hyperextension, which can lead to spinal canal narrowing, ligamentum invagination, and laminae shingling.[6,7] The neck can then be moved into extension for arthrodesis. The position can also be changed without the necessity of the surgical team breaking scrub. The authors reported no complications related to this technique and improvements in cervical lordosis with the most common fusion levels between C2 and T3.[6] We report increased segmental correction at C7–T1–T2 and the use of bivector traction may be more useful for constructs that cross the cervicothoracic junction. Despite an advantage at the cervicothoracic junction, there was no overall difference in sagittal correction suggesting that surgeons should use a positioning technique that they are most comfortable with.

This study has several limitations inherent to its retrospective nature and use of a database. The sample size is relatively small and given the multicenter nature of the study, the positions utilized may be more site specific than patient specific resulting in variability. Additionally, the cohort includes both cervical and cervicothoracic deformity.

In conclusion, postoperative cervical sagittal correction or alignment was not affected by patient position. The majority of segmental correction occurred at C4–5–6 across all positioning methods, while bivector traction had the largest corrective ability at the cervicothoracic junction. These are important considerations for surgical planning in cervical deformity surgery.

processing....