Zero-profile implant system versus novel plate systems after ACDF for comparison of sagittal balance parameters and clinical efficacy analysis.

The zero-profile implant system (Zero-P) and conventional plates have been widely used in anterior cervical discectomy and fusion (ACDF) to treat cervical spondylosis. The purpose of this study was to compare the effects of the application of Zero-P and new conventional plates (ZEVO, Skyline) in ACDF on the sagittal imaging parameters of cervical spondylosis patients and to analyze their clinical efficacy. We conducted a retrospective study on 119 cervical spondylosis patients from January 2018 to December 2021, comparing outcomes between those receiving the Zero-P device (n = 63) and those receiving a novel conventional plate (n = 56, including 46 ZEVO and 10 Skyline plates) through ACDF. Cervical sagittal alignment was assessed pre- and postoperatively via lateral radiographs. The Japanese Orthopedic Association (JOA), Neck Disability Index (NDI), and visual analog scale (VAS) scores were recorded at baseline, after surgery, and at the 2-year follow-up to evaluate patient recovery and intervention success. There were significant differences in the postoperative C0-C2 Cobb angle and postoperative sagittal segmental angle (SSA) between patients in the novel conventional plate group and those in the Zero-P group (P < 0.05). Postoperatively, there were significant changes in the C2‒C7 Cobb angle, C0‒C2 Cobb angle, SSA, and average surgical disc height (ASDH) compared to the preoperative values in both patient groups (P < 0.05). Dysphagia in the immediate postoperative period was lower in the Zero-P group than in the new conventional plate group (0% in the Zero-P group, 7.14% in the novel conventional plate group, P = 0.046), and the symptoms disappeared within 2 years in both groups. There was no statistically significant difference between the two groups in terms of complications of adjacent spondylolisthesis (ASD) at 2 years postoperatively (3.17% in the Zero-P group, 8.93% in the novel conventional plate group; P = 0.252). According to the subgroup analysis, there were significant differences in the postoperative C2‒C7 Cobb angle, C0‒C2 Cobb angle, T1 slope, and ASDH between the ZEVO group and the Skyline group (P < 0.05). Compared with the preoperative scores, the JOA, NDI, and VAS scores of all groups significantly improved at the 2-year follow-up (P < 0.01). According to the subgroup analysis, the immediate postoperative NDI and VAS scores of the ZEVO group were significantly better than those of the Skyline group (P < 0.05). In ACDF, both novel conventional plates and Zero-P can improve sagittal parameters and related scale scores. Compared to the Zero-P plate, the novel conventional plate has a greater advantage in correcting the curvature of the surgical segment, but the Zero-P plate is less likely to produce postoperative dysphagia.

Gong Y ，Zhuo H ，Zhou Z ，Cheng Z ，Gan Y ，He J ，Song Z ，Liu H ，Liu Y ，Liang D ，Jiang X ，Ren H ... -  《Journal of Orthopaedic Surgery and Research》

Comparison of anterior cervical fusion after two-level discectomy or single-level corpectomy: sagittal alignment, cervical lordosis, graft collapse, and adjacent-level ossification.

Single-level corpectomy and two-level discectomy with anterior cervical plating have been reported to have comparable fusion and complication rates. However, there are few large series that have compared the two for sagittal alignment, cervical lordosis, graft subsidence, and adjacent-level ossification. To determine the differences between these two procedures for patients with two-level spondylosis by comparing the pre- and postoperative radiographic data. Retrospective review of prospectively collected data in an academic institution. Fifty-two with a single-level corpectomy and 45 with a two-level anterior cervical discectomy and fusion (ACDF). Pre- and postoperative radiographic data for sagittal alignment, cervical lordosis, subsidence, and adjacent-level ossification. We retrospectively reviewed the lateral cervical radiographs of patients who had a solid fusion after a single-level cervical corpectomy or a two-level ACDF for the treatment of a degenerative cervical spondylosis by a surgeon at an academic institution. The choice of the operation was dependent on the presence or absence of retrovertebral compression. All patients underwent anterior cervical fusion using fibula strut allograft and variable-angle screw-plate fixation. None had had prior cervical spine surgery. Twenty-five were excluded because of inadequate radiographs and follow-up. There were 52 with a single-level corpectomy and 45 with a two-level ACDF. The following were analyzed: 1) sagittal alignment (modified method of Toyama); 2) cervical lordosis measured by Cobb angles of fusion constructs (fusion Cobb) and C2-C7 (C2-C7 Cobb); 3) graft collapse determined by the subsidence of anterior/posterior body height of fused segments (anterior/posterior subsidence) and the cranial/caudal plate-to-disc distances (cranial/caudal subsidence), and the difference between anterior and posterior body height for the fused levels (anteroposterior [AP] difference); and 4) the severity of ossification at two adjacent levels. The mean durations of follow-up were 23.3+/-6.6 (corpectomy) and 25.7+/-6.2 (ACDF) months, range 12 to 45 months. There were no significant differences between the two groups in sagittal alignment, cervical lordosis, graft collapse, and adjacent-level ossification. Graft subsidence and loss of cervical lordosis occurred significantly more during the first 6 weeks after surgery (all measurements, p<.0001) than after 6 weeks, with no significant difference between the two groups. Posterior and caudal end plate subsidence significantly progressed after 6 weeks in Group 1 (p=.04, p=.02). The final follow-up Cobb angle positively correlated with preoperative and immediate postoperative Cobb angles (r=0.437, p<.0001; r=0.727, p<.0001), caudal subsidence (r=0.270, p=.008), and the final AP difference (r=0.915, p<.0001) but did not correlate with surgery level, preoperative and final sagittal alignments, anterior/posterior subsidence, and cranial subsidence. Anterior/posterior subsidence was significantly more strongly related with caudal subsidence (r=0.607, p<.0001; r=0.424, p<.0001) than cranial (r=0.277, p=.007; r=0.211, p=.040) but did not correlate with pre- and postoperative fusion Cobb, and preoperative and the last sagittal alignments. Our data suggest that the two procedures yield comparable results in terms of sagittal alignment, cervical lordosis, graft subsidence, and adjacent-level ossification. Graft subsidence and loss of cervical lordosis appeared to occur mainly during the first 6 weeks after surgery. Single-level corpectomy and fusion continued to subside at the posterior portion of caudal end plate even after 6 weeks. On the other hand, graft subsidence did not correlate with preoperative and final postoperative sagittal alignments.

Park Y ，Maeda T ，Cho W ，Riew KD ... -  《-》

Correlation between axial symptoms and cervical sagittal alignment parameters in patients with two-level or three-level cervical spondylotic myelopathy: anterior cervcial discectomy and fusion versus hybird surgery.

To comparatively analyze the correlation between axial symptoms (AS) and cervical sagittal alignment parameters after anterior cervical discectomy and fusion (ACDF) and hybrid surgery (HS). From January 2018 to June 2023, 74 patients who underwent ACDF (n = 36) or HS (n = 38) for two-level or three-level cervical spondylotic myelopathy were retrospectively analyzed. The Visual Analogue Scale (VAS), Japanese Orthopedic Association (JOA), Neck Disability Index (NDI) were recorded to assess clinical outcomes. Cervical sagittal alignment parameters (Cobb's angle C2-7, C7 slope [C7S], and C2-7 sagittal vertical axis [C2-7 SVA]) were measured preoperatively, 3 days postoperatively, and at the last follow-up. The range of motion (ROM) of C2-7 and ROM of surgical segment were measured. The occurrence of AS was observed at the last follow-up. Logistic regression was used to analyze the correlation between postoperative AS and cervical sagittal alignment parameters. Both in ACDF group and HS group, VAS, JOA and NDI scores showed significant improvements at 3-day postoperation and at the last follow-up (P < 0.05). However, there was no significant difference between the two groups (P > 0.05). The Cobb's angle C2-7 and C7S were significantly increased at 3 days postoperation compared with pre-operatively in both groups (P < 0.05). C2-7SVA was increased in both groups 3 days after surgery compared with pre-operatively, but there was no significant difference (P > 0.05). At the last follow-up, the ROM of C2-7 in ACDF group was significantly smaller than HS group (P < 0.05). The prevalence of postoperative AS in the ACDF group and HS group was 41.7 and 18.4%, respectively, with statistical difference between the two groups (P < 0.05). When simple Logistic regression analysis was used, the last Cobb's angle C2-7 (β = -0.088), the last C2-7SVA (β = 0.099) in ACDF group and the last C2-7SVA (β = 0.222) in HS group were all correlated with the occurrence of postoperative AS. When multiple Logistic regression analysis was used, only the last C2-7SVA (β = 0.181) in the HS group was positively correlated with the occurrence of postoperative AS. Both ACDF and HS can achieve satisfied clinical outcomes. ACDF and HS can improve cervical sagittal balance to a certain extent, and HS is superior to ACDF in maintaining ROM. The decrease of the last Cobb's angle C2-7 and the increase of the last C2-7SVA may be related to the occurrence of AS after ACDF. The increase of the last C2-7SVA was an independent risk factor for the occurrence of AS after HS.

Qiu Z ，Xiong Y ，Yu X ，Li W ，Ma Y ，Feng N ，Zhou S ，Jiang G ，Zhou Y ... -  《-》

Anterior cervical discectomy and fusion with a zero-profile integrated plate and spacer device: a clinical and radiological study: Clinical article.

Njoku I Jr ，Alimi M ，Leng LZ ，Shin BJ ，James AR ，Bhangoo S ，Tsiouris AJ ，Härtl R ... -  《-》

Analysis of Cervical Sagittal Balance in Treating Cervical Spondylotic Myelopathy: 1-Level Anterior Cervical Corpectomy and Fusion Versus 2-Level Anterior Cervical Discectomy and Fusion.

Zhou P ，Zong L ，Wu Q ，Ye Y ，Zhang Z ，Yang H ，Zhang C ，Wang S ... -  《MEDICAL SCIENCE MONITOR》