Abudouaini Haimiti, Liu Hao, Huang Chengyi, Wang Beiyu, Ding Chen, Meng Yang, Yang Yi, Wu Tingkui
Department of Orthopedic Surgery, West China Hospital, Sichuan University, Sichuan, China.
Department of Orthopedic Surgery, West China Hospital, Sichuan University, Sichuan, China.
World Neurosurg. 2021 Jan;145:e61-e67. doi: 10.1016/j.wneu.2020.09.069. Epub 2020 Sep 18.
Narrowing of intervertebral space height (ISH) is an important pathological change in degenerative spinal disease, and ideal intraoperative distraction and postoperative intervertebral space maintenance is one of the most expectant goals pursued by spinal surgeons. The effect of postoperative ISH changing on the clinical and radiological outcomes after cervical disc replacement is not fully understood, however.
In this study, the height variation and general trend of postoperative ISH in all patients were analyzed. The patients were divided into 3 groups based on the change of postoperative intervertebral space height (ISH)-group A (ISH <2 mm), group B (ISH 2-4 mm), and group C (ISH >4mm)-and the clinical and radiographic results compared among the 3 groups.
A total of 120 consecutive patients with symptomatic cervical disc disease were included in this study. The results showed that the mean ISH increased significantly from 0.729 mm before surgery to 1.143 mm at 1 week, then gradually decreased to 1.032 mm at 3 months, 0.980 mm at 6 months, 0.760 mm at one year, and 0.750 mm at the final follow-up. The average postoperative Neck Disability Index (NDI) was 19.73 ± 0.81, 13.74 ± 4.94, 17.19 ± 4.22, respectively, in the 3 groups at 1 year after surgery and the average range of motion (ROM) was 5.44° ± 3.85° in group A, 9.34° ± 4.38° in group B, and 6.51° ± 4.38° in group C. The mean diameter of the intervertebral foramen was 6.54 ± 1.86 mm in group A, 9.63 ± 2.38 mm in group B, and 9.31 ± 1.68 mm in group C. Degeneration at the superiorly adjacent disc level was observed in 13.51% patients in group A, 9.37% in group B, and 21.05% in group C. Degeneration at the inferiorly adjacent level was radiographically identified in 21.62% in group A, 14.06% in group B, and 26.32% in group C.
This study revealed that cervical disc replacement cannot maintain the intervertebral disc height obtained immediately after surgery. There is no obvious correlation between the change in intervertebral space height and clinical efficacy in the early postoperative stage. Nonetheless, the intervertebral disc height may affect the NDI index 1 year after surgery. If the postoperative intervertebral space height change can be maintained at 2-4 mm at 1 year, satisfactory ROM, intervertebral foramen diameter, and relatively low adjacent segment degeneration may be obtained after cervical disc replacement.
椎间隙高度（ISH）变窄是退行性脊柱疾病的重要病理变化，理想的术中撑开及术后椎间隙维持是脊柱外科医生最期望实现的目标之一。然而，术后ISH变化对颈椎间盘置换术后临床及影像学结果的影响尚未完全明确。
本研究分析了所有患者术后ISH的高度变化及总体趋势。根据术后椎间隙高度（ISH）的变化将患者分为3组——A组（ISH<2mm）、B组（ISH 2 - 4mm）和C组（ISH>4mm）——并比较3组的临床及影像学结果。
本研究共纳入120例有症状的颈椎间盘疾病患者。结果显示，平均ISH从术前的0.729mm显著增加至术后1周时的1.143mm，随后逐渐下降，至3个月时为1.032mm，6个月时为0.980mm，1年时为0.760mm，末次随访时为0.750mm。术后1年，3组患者的平均颈部功能障碍指数（NDI）分别为19.73±0.81、13.74±4.94、17.19±4.22，平均活动范围（ROM）在A组为5.44°±3.85°，B组为9.34°±4.38°，C组为6.51°±4.38°。A组椎间孔平均直径为6.54±1.86mm，B组为9.63±2.38mm，C组为9.31±1.68mm。A组13.51%的患者、B组9.37%的患者及C组21.05%的患者在相邻上位椎间盘水平出现退变。A组21.62%、B组14.06%及C组26.32%的患者在相邻下位椎间盘水平经影像学检查发现退变。
本研究表明，颈椎间盘置换术后无法维持术后即刻获得的椎间盘高度。术后早期椎间隙高度变化与临床疗效之间无明显相关性。尽管如此，椎间盘高度可能会影响术后1年的NDI指数。如果术后1年椎间隙高度变化能维持在2 - 4mm，则颈椎间盘置换术后可能获得满意的ROM、椎间孔直径及相对较低的相邻节段退变。
