Objective: To explore the short-term outcomes of 3D-printing stand-alone artificial vertebral body (AVB) in the surgical procedure of anterior cervical corpectomy and fusion (ACCF).
Methods: Following the proposal of IDEAL (idea, development, exploration, assessment, and long-term follow-up) framework, we designed and conducted this single-armed, retrospective cohort study. The patients with cervical spondylotic myelopathy were recruited, and these patients exclusively received the surgical procedure of single-level ACCF in our single center. After the process of corpectomy, the size was tailored using different trials and the most suitable stand-alone AVB was then implanted. This AVB was manufactured by the fashion of 3D-printing. Two pairs of screws were inserted in an inclined way into the adjacent vertebral bodies, to stabilize the AVB. The participants were regularly followed-up after the operation. Their clinical data were thoroughly reviewed. We assessed the neurological status according to Japanese Orthopedic Association (JOA) scale. We determined the fusion based on imaging examination six months after the operation. The recorded clinical data were analyzed using specific software and they presented in suitable styles. Paired t test was employed in comparison analysis.
Results: In total, there were eleven patients being recruited eventually. The patients were all followed up over six months after the operation. The mean age of the cohort was (57.2±10.2) years. The mean operation time was (76.1±23.1) min and the median bleeding volume was 150 (100, 200) mL. The postoperative course was uneventful for all the cases. Dysphagia, emergent hematoma, and deterioration of neurological function did not occur. Mean JOA scores were 13.2±2.2 before the operation and 16.3±0.8 at the final follow-up, which were significantly different (P < 0.001). The mean recovery rate of neurological function was 85.9%. By comparing the imaging examinations postoperatively and six months after the operation, we found that the average subsidence length was (1.2±1.1) mm, and that there was only one cases (9.1%) of the severe subsidence (>3 mm). We observed significant improvement of cervical lordosis after the operation (P=0.013). All the cases obtained solid fusion.
Conclusion: 3D-printing stand-alone AVB presented favorable short-term outcome in one-level ACCF in this study. The fusion rate of this zero-profile prosthesis was satisfactory and the complication rate was relatively low.
目的: 探讨自稳式人工椎体(artificial vertebral body，AVB)在颈前路椎体次全切除内固定融合手术(anterior cervical corpectomy and fusion，ACCF)中的短期应用效果。
方法: 遵循牛津IDEAL(Idea, Development, Exploration, Assessment, and Long-term Follow-up)方法学原则，采用单臂探索型研究的方法，纳入脊髓型颈椎病患者进行回顾性分析。所有患者均接受单节段ACCF手术，术中植入3D打印自稳式AVB，术后规律随访。采用日本骨科协会(Japanese Orthopedics Association，JOA)脊髓损害评分表评估手术前后神经功能改善情况，依据术后6个月的影像学测量数据评估融合情况。
结果: 共纳入11例病例，随访时间均超过6个月，手术时的平均年龄(57.2±10.2)岁，平均手术时间(76.1±23.1) min，中位出血量150(100, 200) mL。术后无吞咽困难、血肿形成、神经功能损伤加重等并发症出现。至末次随访，JOA评分由术前的13.2±2.2恢复至末次随访时的16.3±0.8，恢复率为85.9%。假体平均沉降距离为(1.2±1.1) mm，1例假体出现超出3 mm的严重沉降(9.1%)。颈椎前凸角度较术前显著改变(P=0.013)。至术后6个月时，所有病例均实现融合。
结论: 自稳式AVB在单节段ACCF中的短期应用效果良好，融合率高，具有零切迹的优势，并发症少。
Keywords: 3D-printing; Artificial vertebral body; Cervical spondylotic myelopathy; Stand-alone; Zero-profile.