Clinical impact of 3-level anterior cervical decompression and fusion (ACDF) on the occipito-atlantoaxial complex: a retrospective study of patients who received a zero-profile anchored spacer versus cage-plate construct

Is the Zero-P Spacer Suitable for 3-Level Anterior Cervical Discectomy and Fusion Surgery in Terms of Sagittal Alignment Reconstruction: A Comparison Study with Traditional Plate and Cage System

“…In the present study, when speaking generally, the changes of the cervical sagittal alignment using a Zero-P spacer or a plate and cage system were similar to those in previously published papers [ 8 , 28 , 29 , 30 ]. For both groups, the C2-C7 Cobb angle, the fused segment Cobb angle, as well as the fused segment disc wedge were found to be significantly improved immediately after surgery, and then these changes gradually decreased during follow-ups ( Table 4 ).…”

“…They found that, during the postoperative follow-up, the Zero-P spacer demonstrated a higher loss of correction on the disc height and C2-C7 Cobb angle compared to the plate and cage system. Recently, Xiao et al [ 30 ] studied the impact of 3-level ACDF on the occipito-atlantoaxial complex between the Zero-P spacer and the plate-cage system. In the Zero-P group, the restoration of cervical lordosis (C2-C7 Cobb angle) was significantly lost at the 1-year follow-up compared with the plate-cage group.…”

“…For both groups, the C2-C7 Cobb angle, the fused segment Cobb angle, as well as the fused segment disc wedge were found to be significantly improved immediately after surgery, and then these changes gradually decreased during follow-ups ( Table 4 ). This phenomenon could be attributed to the subtle diminishing of disc height and wedging among the fused segments [ 29 , 30 ]. Although we did not observe any case with obvious cage subsidence in our series, this trivial change at each disc level may add up to a certain extent, causing the loss of correction in the cervical sagittal alignment.…”

“…In 2017, Chen et al [ 28 ] compared the mid-term results of 3-level ACDF between Zero-P spacer and the traditional cervical plate, and reported that, although the Zero-P spacer was similar to the traditional cervical plate in clinical outcomes, it was inferior in the restoration of cervical lordosis and could not reconstruct a better sagittal cervical alignment in 3-level fixation. Thereafter, Sun et al [ 29 ] and Xiao et al [ 30 ] also reported that, for 3-level ACDF surgery, a Zero-P spacer was not as comparable as the plate-cage system in maintaining postoperative cervical alignment. As a matter of fact, in our clinical practice, we have noticed that in some patients with a certain preoperative cervical lordosis, good sagittal cervical alignment reconstruction can be achieved for 3-level ACDF even by using Zero-P spacers.…”

Anatomical and Imaging Study on the Optimum Entry Point and Trajectory for Anterior Transpedicular Root Screw Placement into the Lower Cervical Spine

“…Clinically, surgical treatment is mainly adopted to relieve spinal cord and nerve root compression, restore the normal sequence and physiological curvature of cervical spine (CS), and rebuild the stability of CS. Anterior cervical decompression and fusion is a common method to treat lower cervical diseases [ 3 , 4 ], most of which are fixed with unicortical cervical vertebral screws, with a good fixation effect for patients with single-level cervical diseases. However, a combination of anterior and posterior surgery is usually required for those with single-level three-column injury or multilevel anterior compression treated by anterior vertebral screws, with anterior surgery for decompression and posterior surgery for fixation.…”