目的: 通过比较颈椎脊索瘤全脊椎切除术后3D打印人工椎体和钛网下沉率的差异，探讨3D打印人工椎体重建前方椎体能否减少术后内植物的下沉。方法: 回顾性分析2005年3月至2019年9月在北京大学第三医院行全脊椎切除术的24例颈椎脊索瘤患者资料，其中采用3D打印人工椎体重建颈椎前方椎体(3D椎体组)有9例，采用钛网重建(钛网组)有15例。收集患者的年龄、性别、椎体CT值、手术信息(手术节段、手术时间、出血量及围手术期并发症)和术后内植物下沉等随访资料，采用SPSS 22.0进行数据分析。结果: 比较两组患者的性别、年龄、椎体CT值、手术节段、手术时间、出血量及围手术期并发症，差异无统计学意义。术后3个月随访内植物下沉显示，3D椎体组有8例椎体高度下降 < 1 mm (无内植物下沉)，1例椎体高度下降>1 mm (轻度内植物下沉)；钛网组有5例椎体高度下降 < 1 mm (无内植物下沉)，8例椎体高度下沉>1 mm (轻度内植物下沉)，2例缺失术后3个月的影像学资料，两组3个月内植物下沉率的比较差异有统计学意义(P < 0.05)。术后12个月随访内植物下沉显示，3D椎体组有8例椎体高度下降 < 1 mm (无内植物下沉)，1例椎体高度下沉>3 mm (重度内植物下沉)；钛网组有4例椎体高度下降 < 1 mm (无内植物下沉)，2例椎体高度下沉>1 mm (轻度内植物下沉)，9例椎体高度下沉>3 mm (重度内植物下沉)，两组12个月内植物下沉率的比较差异有统计学意义(P < 0.01)，且两组的重度内植物下沉率(椎体高度下沉>3 mm) 比较差异有统计学意义(P < 0.05)。术后24个月随访内植物下沉显示，3D椎体组死亡1例，7例椎体高度下降 < 1 mm (无内植物下沉)，1例椎体高度下沉>3 mm (重度内植物下沉)；钛网组死亡1例，失访1例，1例椎体高度下降 < 1 mm (无内植物下沉)，1例椎体高度下沉>1 mm (轻度内植物下沉)，11例椎体高度下沉>3 mm (重度内植物下沉)，两组24个月内植物下沉率比较差异有统计学意义(P < 0.01)，且两组的重度内植物下沉率比较差异有统计学意义(P < 0.01)。结论: 在颈椎脊索瘤的全脊椎切除术中，3D打印人工椎体可提供可靠的即刻和中远期的颈椎稳定性，与钛网重建相比，能够减少术后内植物下沉的发生率。

Objective: To investigate whether 3D-printed artificial vertebral body can reduce prosthesis subsidence rate for patients with cervical chordomas, through comparing the rates of prosthesis subsidence between 3D printing artificial vertebral body and titanium mesh for anterior spinal reconstruction after total spondylectomy. Methods: This was a retrospective analysis of patients who underwent surgical treatment for cervical chordoma at our hospital from March 2005 to September 2019. There were nine patients in the group of 3D artificial vertebral body (3D group), and 15 patients in the group of titanium mesh cage (Mesh group). The patients' characteristics and treatment data were extracted from the medical records, including age, gender, CT hounsfield unit of cervical vertebra and surgical information, such as the surgical segments, time and blood loss of surgery, frequency and degree of prosthesis subsidence after surgery. Radiographic observations of prosthesis subsidence during the follow-up, including X-rays, CT, and magnetic resonance imaging were also collected. SPSS 22.0 was used to analysis the data. Results: There was no significant difference between the two groups in gender, age, CT hounsfield unit, surgical segments, time of surgery, blood loss of posterior surgery and total blood loss. Blood loss of anterior surgery was 700 (300, 825) mL in 3D group and 1 500 (750, 2 800) mL in Mesh group (P < 0.05). The prosthesis subsidence during the follow-up, 3 months after surgery, there was significant difference between the two groups in mild prosthesis subsidence (P < 0.05). The vertebral height of the 3D group decreased less than 1 mm in eight cases (no prosthesis subsidence) and more than 1 mm in one case (mild prosthesis subsidence). The vertebral height of the Mesh group decreased less than 1 mm in five cases (no prosthesis subsidence), and more than 1 mm in eight cases (mild prosthesis subsidence). Two patients did not have X-rays in 3 months after surgery. There was a statistically significant difference between the two groups in the prosthesis subsidence rate at the end of 12 months (P < 0.01). The vertebral height of eight cases in the 3D group decreased less than 1 mm (no prosthesis subsidence) and one case more than 3 mm (severe prosthesis subsidence). Four of the 15 cases in the Mesh group decreased less than 1 mm (no prosthesis subsidence), two cases more than 1 mm (mild prosthesis subsidence), and nine cases more than 3 mm (severe prosthesis subsidence). There was a statistically significant difference between the two groups in the prosthesis subsidence rate at the end of 24 months (P < 0.01). The vertebral height of seven cases in the 3D group decreased less than 1 mm (no prosthesis subsidence), one case more than 3 mm (severe prosthesis subsidence), and one case died with tumor. One case in the Mesh group decreased less than 1 mm (no prosthesis subsidence), one case more than 1 mm (mild prosthesis subsidence), 11 case more than 3 mm (severe prosthesis subsidence), one case died with tumor and one lost the follow-up. Moreover, at the end of 12 months and 24 months, there was significant difference between the two groups in severe prosthesis subsidence rate (P < 0.01). Conclusion: 3D-printed artificial vertebral body for anterior spinal reconstruction after total spondylectomy for patients with cervical chordoma can provide reliable spinal stability, and reduce the incidence of prosthesis subsidence after 2-year follow-up.