Optimizing Biomechanics of Surgical Correction for Lumbar Flatback Deformity

优化腰椎平背畸形手术矫正的生物力学

• 批准号: 10223462
• 负责人: Avinash G. Patwardhan
• 金额: --
• 依托单位: EDWARD HINES JR VA HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-07-01 至 2022-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10223462
• 关键词: Address; Adult; Affect; Age; Analysis of Variance; Anatomy; Back Pain; Biomechanics; Cadaver; Caring; Clinical; Clinical Research; Complex; Cone; Data; Deformity; Disease; Effectiveness; Equilibrium; Excision; Experimental Designs; Fatigue; Goals; Height; Hemorrhage; High Prevalence; Hip region structure; Human; Iatrogenesis; Implant; Incidence; Individual; Knee; Knowledge; Lead; Ligaments; Literature; Lordosis; Lumbar Curve; Measures; Methods; Morbidity - disease rate; Morphology; Muscle; Muscle Fatigue; Operative Surgical Procedures; Osteotomy; Outcome; Patients; Pelvis; Population; Posture; Procedures; Provider; Regression Analysis; Research; Risk; Shapes; Specific qualifier value; Specificity; Specimen; Statistical Data Interpretation; Stress; Surgeon; Techniques; Testing; Time; Translations; Vertebral column; Veterans; Walking; age related; arm; base; comorbidity; distraction; dorsal column; falls; flexibility; functional loss; improved; improved functioning; improved outcome; in vivo; military veteran; older patient; operation; response; restoration; sacrum; surgery outcome

Purpose: The long-term goal of this research is to improve the outcomes of surgical correction for lumbar flatback deformity, which is a complex disorder that can affect a large segment of the veteran population. In flatback deformity the torso pitches forward and affects the patient’s ability to stand upright and walk due to muscle fatigue and worsening back pain, leading to functional loss. The goal of surgery is to correct the sagittal malalignment to reduce muscle fatigue and allow patients to stand upright and ambulate, thus improving function. Surgeons who treat older veterans want to know: (1) how much lordosis restoration is sufficient to reduce the burden on muscles to maintain an upright posture; and (2) can this be achieved using a less invasive surgical technique to minimize complications and morbidity. Hypothesis: Our central hypothesis is that restoring lumbar lordosis using lordotic interbody fusion cages implanted in multiple disc spaces will minimize the forces needed to maintain an upright posture in specimens with loss of lordosis across L4 to sacrum. Specific aims: (1) We will use human cadaveric thoracolumbar (T10-sacrum) spine specimens with a range of PI values (35°-70°; the average adult PI is 52°) to quantify the shear force and moment required at the cephalad and caudal boundaries of the specimen to maintain an upright standing posture under the following conditions: (1) hypolordosis across L4-S1, creating a PI-LL mismatch (degenerative or iatrogenic), and (2) improvement of L1-S1 lordosis using lordotic interbody fusion cages placed at one or more segments of the lumbar spine, first without and then with posterior column (facet) osteotomies (PCO). (2) We will analyze the data collected in aim 1 to: (1) define a relationship between the extent of PI-LL mismatch and forces needed to maintain an upright standing posture for the reconstructed spines, and (2) quantify the influence of the following study variables on the ability of lordotic interbody cages to improve standing lumbar lordosis: (a) number of reconstructed disc spaces, (b) specimen’s PI value and flexibility (that is, segmental mobility in flexion and extension), (c) influence of PCO to yield additional correction. Methods: The experimental design consists of two arms: degenerative, and iatrogenic. In the iatrogenic arm, a hypolordotic fusion across L4-S1 will be created by applying distraction forces across pedicle screws inserted in L4, L5 and S1 pedicles; whereas, in the degenerative arm we will select specimens in which there is sufficient loss of disc heights at the L5-S1 and L4-L5 disc spaces. In the iatrogenic arm, surgical restoration of L1-S1 lordosis will be performed by implanting lordotic interbody cages at L3-L4 and L2-L3 disc spaces cephalad to the hypolordotic L4-S1 fusion; whereas, in the degenerative arm surgical restoration of segmental lordosis will be performed at L5-S1 and L4-L5 disc spaces. In both arms of the study, we will aim to eliminate the PI-LL mismatch (PI-LL ≤5°) by adding additional segments where lordotic interbody cages are implanted and, if necessary, performing posterior column (facet) osteotomies to augment the correction potential of interbody cages. In each state the specimens will undergo a battery of biomechanical tests to quantify the shear force and moment required at the cephalad and caudal boundaries of the specimen to maintain an upright posture. Statistical analysis will include repeated-measures ANOVA and multivariate regression analyses. Clinical Impact: The overall percentage of living Veterans expected to be affected by flatback deformity is anticipated to rise as the population ages and lives longer. Thus, the contribution of the proposed research to the knowledge of VA providers who care for our Veterans is likely significant. If the biomechanical data supports the use of segmental lordosis restoration using interbody fusion cages, the less invasive technique will add a valuable option for restoring lumbar lordosis in older patients. The research results are readily applicable for quick translation to veteran- and civilian patients if found to be beneficial.

目的：本研究的长期目标是改善腰椎手术矫正的结果。 扁平背畸形，这是一种复杂的疾病，可以影响到很大一部分退伍军人人口。在……里面 扁平背畸形躯干前倾，影响患者直立行走能力 肌肉疲劳和背部疼痛加重，导致功能丧失。手术的目的是矫正矢状面 对齐失调，以减少肌肉疲劳，并允许患者直立和行走，从而改善 功能。治疗老年退伍军人的外科医生想知道：(1)多少前凸恢复足以 减轻肌肉的负担以保持直立姿势；以及(2)这是否可以使用侵入性较小的 将并发症和发病率降至最低的外科技术。 假设：我们的中心假设是使用前路椎间融合器恢复腰椎前凸 植入多个椎间隙将使保持标本直立姿势所需的力降至最低 从L4到骶骨的腰椎前凸丧失。 具体目标：(1)我们将使用人类身体胸腰段(T10-Socrum)脊柱标本 PI值(35°-70°；成人平均PI值为52°)，以量化头骨所需的剪切力和力矩 在下列情况下保持直立姿势的标本的尾部边界： (1)横跨L4-S1的腰椎后凸，造成PI-LL不匹配(退行性或医源性)，以及(2)改善 使用放置在一个或多个腰椎节段的L1-S1前凸椎间融合器 无后柱(小关节)截骨术(PCO)。 (2)我们将分析在目标1中收集的数据以：(1)定义PI-L1失配程度之间的关系 以及重建脊柱保持直立姿势所需的力，以及(2)量化 以下研究变量对前凸椎间融合器改善腰椎站立能力的影响 前凸度：(A)重建的椎间隙数目，(B)标本的PI值和柔韧性(即节段性 屈曲和伸展时的活动度)，(C)PCO对产生额外矫正的影响。 方法：实验设计分为退行性和医源性两部分。在医源性手臂上，一个 横跨L4-S1的椎弓根融合将通过将牵引力施加于插入到 L4、L5和S1椎弓根；而在退变臂中，我们将选择有足够丢失的标本 L5-S1和L4-L5圆盘空间的圆盘高度。医源性上肢L1-S1前凸的手术修复 将通过在L3-L4和L2-L3椎间隙头侧植入前凸椎间融合器至 L4-S1融合；而在退变的手臂中，节段性前凸的手术重建将是 在L5-S1和L4-L5椎间隙执行。在这项研究的两个方面，我们都将致力于消除PI-LL失配 (PI-L1≤5°)，在植入前凸椎间融合器的地方增加额外的节段，如有必要， 后柱(小关节)截骨术以增加椎间融合器的矫正潜力。在每一个中 声明试件将接受一系列生物力学测试，以量化剪切力和力矩 在标本的头部和尾部边界需要保持直立姿势。 统计分析将包括重复测量、方差分析和多元回归分析。 临床影响：预计将受到扁平背畸形影响的活着退伍军人的总体百分比为 预计随着人口老龄化和寿命延长，这一数字将上升。因此，拟议研究的贡献在于 照顾退伍军人的退伍军人退伍军人服务提供者的知识可能非常重要。如果生物力学数据支持 使用椎间融合器重建节段性前凸，创伤较小的技术将增加 对于老年患者恢复腰椎前凸有价值的选择。该研究成果可直接应用于 快速翻译给退伍军人和平民患者，如果发现是有益的。