Liu Jiantao, He Xijing, Gao Zhengchao, Niu Binbin, Lv Dongbo, Gao Yanzheng
Department of Spine and Spinal Cord, Henan Provincial People's Hospital, No.7, the Weft Fifth Road, Jinshui District, Zhengzhou, Henan, People's Republic of China.
Department of Orthopedics, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, People's Republic of China.
Arch Orthop Trauma Surg. 2019 Jun;139(6):751-760. doi: 10.1007/s00402-018-03106-2. Epub 2019 Feb 12.
To design a novel prosthesis, a movable artificial lumbar complex (MALC), for non-fusion reconstruction after lumbar subtotal corpectomy and to evaluate the stability, range of motion and load-bearing strength in the human cadaveric lumbar spine.
Biomechanical tests were performed on lumbar spine specimens from 15 healthy cadavers which were divided in three groups: non-fusion, fusion and intact group. The range of motion (ROM), stability and load-bearing strength were measured.
The prosthesis was composed of three parts: the upper and lower artificial lumbar discs and the middle artificial vertebra. Both the MALC and titanium mesh cage re-established vertebral height, and no spinal cord compression or prosthesis dislocation was observed at the operative level. Regarding stability, there was no significant difference in all directions between the intact group and non-fusion group (P > 0.05). Segment movements of the specimens in the non-fusion group revealed significantly decreased T12-L1 ROM and significantly increased L1-2 and L2-3 ROM in flexion/extension and lateral bending compared with those in the fusion group (P < 0.05). Regarding load-bearing strength, when the lumbar vertebra was ruptured, there was no damage to the MALC and titanium mesh cage, but the maximum load in the non-fusion group was larger (P > 0.05).
Compared with titanium cages, the MALC prosthesis not only restored the vertebral height and effectively preserved segment movements without any abnormal gain of mobility in adjacent inter-vertebral spaces but also bore the lumbar load and reduced the local stress load of adjacent vertebral endplates.
设计一种新型假体——可移动人工腰椎复合体（MALC），用于腰椎次全切除术后的非融合重建，并评估其在人体尸体腰椎中的稳定性、活动范围和承重强度。
对15具健康尸体的腰椎标本进行生物力学测试，将其分为三组：非融合组、融合组和完整组。测量活动范围（ROM）、稳定性和承重强度。
该假体由三部分组成：上下人工腰椎间盘和中间人工椎体。MALC和钛网笼均重建了椎体高度，手术节段未观察到脊髓受压或假体脱位。在稳定性方面，完整组和非融合组在各个方向上均无显著差异（P>0.05）。与融合组相比，非融合组标本在屈伸和侧方弯曲时T12-L1的ROM显著降低，L1-2和L2-3的ROM显著增加（P<0.05）。在承重强度方面，腰椎椎体破裂时，MALC和钛网笼均未受损，但非融合组的最大负荷更大（P>0.05）。
与钛笼相比，MALC假体不仅恢复了椎体高度，有效保留了节段活动，相邻椎间间隙无异常活动增加，还能承受腰椎负荷，降低相邻椎体终板的局部应力负荷。
