Spine: ThoracoLumboSacral (TLS) Long Constructs Statistical Model

The lumbosacral junction is a susceptible transition point between the mobile lumbar spine and the rigid pelvis. Already subject to high rates of pathology, this level can experience up to 67-69% radiographic adjacent segment degeneration following instrumentation with long constructs terminating at L5. Studies have shown that up to 22 % of adolescent scoliosis constructs terminating in the lower lumbar spine required revision within a 15-year follow up period. The sacropelvis is often included in cases of deformity correction including those requiring osteotomy, high grade spondylolistheisis, and “long” thoracolumbar constructs. What constitutes a long posterior construct, and when sacropelvic fixation is required are unclear at this time, and the optimal sacropelvic fixation technique for varying construct lengths has yet to be determined. Biomechanical and clinical evidence supports that iliac screws remain the strongest, most definitive method of sacropelvic fixation. However, iliac screws also may increase operative time, blood loss, postoperative sacroiliac (SI) joint pain, and rarely neurovascular injury. Given the associated morbidity, iliac screws are not currently considered “the standard of care” for all long lumbar and thoracolumbar constructs. Understanding the impact that construct length, construct type, and loading direction have on kinematics of the base of the spine is in important factor in finding optimal solutions for each surgical intervention. This project aims to elucidate the relationship of all these variables. <br/><br/>This project includes the following software/data packages: <br/> <ul> <li> <a href="https://simtk.org/frs?group_id=1295#pack_1933">TLS Constructs Model Tool </a> : This user interface provides a simple way to interact with the statistical model and see the effects of varying construct length, construct type, and loading direction. </li> </ul>

腰骶关节为活动性腰椎与刚性骨盆之间的易感过渡区域。该区域本已承受高病理发病率，在L5水平使用长期构建物进行固定后，该段可出现高达67-69%的相邻节段影像学退行性变。研究表明，高达22%的青少年脊柱侧弯病例，其构建物终止于下腰椎，在15年的随访期内需要再次手术。在需要骨切开、高度脊柱滑脱以及“长”型胸腰段构建物矫正的病例中，常需将骶髂关节纳入手术范围。目前，关于何为长型后部构建物以及何时需要骶髂关节固定尚无明确界定，不同构建物长度下的最优骶髂关节固定技术亦未确定。生物力学和临床证据表明，髂骨螺钉是骶髂关节固定的最强、最确定的手段。然而，髂骨螺钉也可能增加手术时间、出血量、术后骶髂关节（SI）疼痛，以及罕见的情况下神经血管损伤。鉴于这些并发症，髂骨螺钉目前并不被视为所有长型腰椎和胸腰段构建物的“标准治疗方案”。理解构建物长度、构建物类型和加载方向对脊柱基底运动学的影响，是寻找每项手术干预最优解决方案的重要因素。本课题旨在阐明所有这些变量的关系。 <br/><br/>本课题包括以下软件/数据包： <br/> <ul> <li> <a href="https://simtk.org/frs?group_id=1295#pack_1933">TLS Constructs Model Tool </a> : 此用户界面提供了一种简单的方式与统计模型交互，并观察构建物长度、构建物类型和加载方向变化的效果。 </li> </ul>