Erkan Serkan, Rivera Yamil, Wu Chunhui, Mehbod Amir A, Transfeldt Ensor E
Department of Orthopaedics and Traumatology, Celal Bayar University, School of Medicine, Izmir Cad. No.10, Manisa 45050, Turkey.
Spine J. 2009 Oct;9(10):830-5. doi: 10.1016/j.spinee.2009.04.014. Epub 2009 May 28.
Multilevel lumbar disc disease (MLDD) is a common finding in many patients. Surgical solutions for MLDD include fusion or disc replacement. The hybrid model, combining fusion and disc replacement, is a potential alternative for patients who require surgical intervention at both L5-S1 and L4-L5. The indications for this hybrid model could be posterior element insufficiency, severe facet pathology, calcified ligamentum flavum, and subarticular disease confirming spinal stenosis at L5-S1 level, or previous fusion surgery at L5-S1 and new symptomatic pathology at L4-L5. Biomechanical data of the hybrid model with the Maverick disc and anterior fusion are not available in the literature.
To compare the biomechanical properties of a two-level Maverick disc replacement at L4-L5, L5-S1, and a hybrid model consisting of an L4-L5 Maverick disc replacement with an L5-S1 anterior lumbar interbody fusion using multidirectional flexibility test.
An in vitro human cadaveric biomechanical study.
Six fresh human cadaveric lumbar specimens (L4-S1) were subjected to unconstrained load in axial torsion (AT), lateral bending (LB), flexion (F), extension (E), and flexion-extension (FE) using multidirectional flexibility test. Four surgical treatments-intact, one-level Maverick at L5-S1, two-level Maverick between L4 and S1, and the hybrid model (anterior fusion at L5-S1 and Maverick at L4-L5) were tested in sequential order. The range of motion of each treatment was calculated.
The Maverick disc replacement slightly reduced intact motion in AT and LB at both levels. The total FE motion was similar to the intact motion. However, the E motion is significantly increased (approximately 50% higher) and F motion is significantly decreased (30%-50% lower). The anterior fusion using a cage and anterior plate significantly reduced spinal motion compared with the condition (p<.05). No significant differences were found between two-level Maverick disc prosthesis and the hybrid model in terms of all motion types at L4-L5 level (p>.05).
The Maverick disc preserved total motion but altered the motion pattern of the intact condition. This result is similar to unconstrained devices such as Charité. The motion at L4-L5 of the hybrid model is similar to that of two-level Maverick disc replacement. The fusion procedure using an anterior plate significantly reduced intact motion. Clinical studies are recommended to validate the efficacy of the hybrid model.
多节段腰椎间盘疾病（MLDD）在许多患者中很常见。MLDD的手术解决方案包括融合或椎间盘置换。融合与椎间盘置换相结合的混合模型，对于需要在L5-S1和L4-L5节段进行手术干预的患者来说是一种潜在的替代方案。这种混合模型的适应证可能是后部结构不足、严重的小关节病变、黄韧带钙化以及证实L5-S1节段存在椎管狭窄的关节下疾病，或者L5-S1节段既往有融合手术且L4-L5节段出现新的症状性病变。文献中尚无关于Maverick椎间盘与前路融合的混合模型的生物力学数据。
通过多方向灵活性测试，比较L4-L5和L5-S1节段两级Maverick椎间盘置换以及由L4-L5节段Maverick椎间盘置换与L5-S1节段前路腰椎椎间融合组成的混合模型的生物力学特性。
一项体外人体尸体生物力学研究。
使用多方向灵活性测试，对六个新鲜的人体尸体腰椎标本（L4-S1）施加轴向扭转（AT）、侧方弯曲（LB）、前屈（F）、后伸（E）和屈伸（FE）无约束载荷。依次测试四种手术治疗方式——完整状态、L5-S1节段单级Maverick、L4-S1节段两级Maverick以及混合模型（L5-S1节段前路融合和L4-L5节段Maverick）。计算每种治疗方式的活动范围。
Maverick椎间盘置换在两个节段的AT和LB中略微降低了完整状态下的活动度。总的FE活动度与完整状态相似。然而，E活动度显著增加（约高50%），F活动度显著降低（低30%-50%）。与完整状态相比，使用椎间融合器和前路钢板的前路融合显著降低了脊柱活动度（p<0.05）。在L4-L5节段，两级Maverick椎间盘假体与混合模型在所有活动类型方面均未发现显著差异（p>0.05）。
Maverick椎间盘保留了总活动度，但改变了完整状态下的活动模式。这一结果与Charité等无约束装置相似。混合模型在L4-L5节段的活动度与两级Maverick椎间盘置换相似。使用前路钢板的融合手术显著降低了完整状态下的活动度。建议进行临床研究以验证混合模型的疗效。
