【专题文献】之胸腰椎骨折-胸腰段损伤的解剖、生物力学和分型

Seminars in
SPINE SURGERY
Anatomy, Biomechanics, and Classification of Thoracolumbar Injuries胸腰段损伤的解剖、生物力学和分型
Harvey E. Smith, MD,* D. Greg Anderson, MD,* Alexander R. Vaccaro, MD, PhD,?
Todd J. Albert, MD,? Alan S. Hilibrand, MD,? James S. Harrop, MD,? and John K. Ratliff, MD?





The spinal thoracolumbar junction is uniquely predisposed to injury caused by forces transmitted through the region and the anatomy of transition from the thoracic to lumbar regions. Management of thoracolumbar injuries requires an understanding of the anatomy and biomechanics of this region. Classification systems need to be reproducible and should assist with treatment decisions. Semin Spine Surg 22:2-7 © 2010 Elsevier Inc. All rights reserved.
胸椎向腰椎转变的解剖学以及区域性应力传递机制使得胸腰端脊柱的损伤极具特殊性。为了更好的处理胸腰段损伤，需要了解该区域的解剖及生物力学特点。有关的分型系统应具有可重复性并有助于治疗决策。
KEYWORDS spine, trauma, classification, thoracolumbar

Anatomy and Biomechanics
解剖及生物力学

Appreciation of the unique anatomy of the spinal thoracolumbar junction and of the patterns of force transmission through the spinal column is necessary to understand and classify thoracolumbar injuries. The thoracolumbar junction is uniquely predisposed to traumatic injuries caused by high energy forces being transmitted through this region as a result of the transition from the kyphotic thoracic to the lordotic lumbar region. The thoracic region kyphosis ranges from 18° to 51° and the spine transitions to a lumbar lordosis ranging from 42° to 74°.1 The thoracolumbar region (T10-L2) is either straight or slightly kyphotic (0°-10°) in the sagittal plane.1 The kyphotic position of the thoracic spine and the body’s center of gravity being located anterior to the spine causes compressive forces to be transmitted anterior to the vertebral body along with a tensile stretch or distraction of the posterior elements. In the lordotic region of the lower lumbar spine, forces are transferred more posterior relative to the spine, and thus these compressive loads pass through the posterior elements. The exact mechanism of individual thoracolumbar traumatic injuries is complex and depends on the exact posture of the spine at the time of force application.
认清胸腰关节的独特解剖特征以及应力通过脊柱的模式对于胸腰段损伤的理解及分裂是很有必要的。由于在该区域胸椎后凸逐渐向腰椎前凸转换，因此高能力应力传递至该区域所致的胸腰段损伤有其独特的特殊性。胸椎后凸为18°～51°，至腰椎，则转为前凸42°～74°。胸腰段(T10-L2)在矢状位平面为中立或轻度后凸(0°～10°)。由于胸椎后凸以及其重力中心集中在脊柱的前方，导致压缩应力集中在椎体的前侧，而脊柱后侧元件则发生牵张。而在前凸的腰椎区域，压应力主要经脊柱后侧传递。具体到单个的胸腰段损伤的机制是复杂以及千变万化的，还会受到应力施加当时脊柱确切的姿势的影响。
The structure and orientation of the facet joints over this region affects resistance to flexion and extension, coronal rotation, and dislocation. The facet joints of the upper thoracic spine have a coronal orientation and resist flexion and extension. Conversely, the lumbar spine has sagitally oriented facets and subsequently increased motion in flexion and extension.2 The upper thoracic spine is shielded from injury by the associated costovertebral structures.3 The ribs and the chest wall musculature serve to protect the spine and dissipate forces, and this buttresses against the significant compressive forces necessary to produce a vertebral body fracture in a normal bone.
胸腰段关节的结构和位置限制了屈伸、轴向旋转和脱位。上胸椎关节允许一定的轴向旋转，但限制屈伸活动。相反，腰椎关节为矢状位，其屈伸活动范围较大。由于肋椎结构的存在，使得上胸椎的外伤较少。肋骨及胸廓肌肉组织能保护脊柱并分散应力，这种支柱能很好的防止压缩应力所导致的椎体骨折。
As described by Stagnara et al,1 the transition from the anatomy of the thoracic to lumbar spine occurs over a relatively small area (T10-L2). In this transitional region, the spinal column is uniquely predisposed to injury, as the costovertebral structures no longer serve as a buttress and the spine has not yet transitioned to its full lordosis (shifting more of the load to the larger and more sagitally oriented posterior facets). The rotational mechanics of the spine change from relative constraint in flexion or extension to relative constraint in coronal rotation.1,2
Holdsworth4 classified thoracolumbar vertebral body injuries based on mechanism of injury and on the presumed forces acting upon the spinal column and the associated paraspinal脊柱旁的soft tissues. Flexion injuries transmit force through the anterior vertebral body resulting in what Holdsworth termed “wedge fractures.” Noting that the posterior spinal elements and tissues are not generally disrupted in these fractures, Holdsworth considered flexion fractures to be biomechanically stable. Subsequent studies have suggested that compression of the vertebral body with a loss of height greater than 40%-50% of the anterior vertebral body can disrupt posterior spinal elements, potentially leading to instability.5 Flexion-rotation injuries or fractures place a significant strain on the posterior facets, and Holdsworth termed these fractures a “slice fragment.” This disruption of the posterior elements results in the inherent instability of this fracture pattern.
正如Stagnara等所描述的，胸椎到腰椎的解剖变化集中在一个相对较小的区域(T10-L2)。在这个区域中，既缺乏肋椎结构的保护，又没有完整的脊柱前凸（应力无法传递至具有更大更矢状位的关节面），脊柱容易诱发损伤。脊柱的旋转机制由相对限制屈伸转换至限制轴向旋转。Holdsworth基于损伤的机制以对胸腰段椎体损伤进行分类。应力通过椎体前侧导致的屈曲损伤被称为“wedge骨折”，此类骨折后侧脊柱元件以及组织通常是没有发生破裂。Holdsworth认为此类骨折在生物力学上是稳定的。后继的研究提示椎体前侧压缩程度超过40%-50%，可导致后侧元件的破裂，并导致不稳定。屈曲旋转损伤或骨折显著拉紧后侧元件，Holdsworth将这种类型的骨折命名为“切片骨折”。后侧元件的破裂导致这种骨折类型潜在的不稳定。
Extension injuries place the anterior tissues under tension and the posterior elements under compression. These forces may result in avulsion fractures of the anterior vertebral body and fractures of the posterior elements. Simple extension injuries are generally considered biomechanically stable if there is no significant ligamentous disruption. These fractures may be unstable if there is an associated shear component or marked hyperextension . Extension injuries are most commonly seen in the setting of metabolic bone diseases, such as diffuse idiopathic skeletal hyperostosis (DISH) or ankylosing spondylitis (AS) , due to the long lever arms created by the associated ossification across multiple spinal segments. Denis further described a hyperextension fracture-dislocation injury, observed in lumberjacks struck by falling trees, that was inherently unstable due to the complete disruption of the anterior ligaments.6-8
牵伸损伤使得脊柱前侧承受牵张应力而后侧为压缩应力。这些因素导致椎体前方的撕脱骨折以及后侧元件的骨折。如果未合并明显的韧带破裂，单纯的牵张损伤被认为在生物力学上是稳定的。如何合并剪切或显著的过伸，则骨折为稳定。牵伸损伤多见于代谢骨疾病，例如广泛性特发性骨质增生或强直性脊柱炎，由于多个节段的骨化作用导致作用力臂变长。Denis进一步描述了过伸骨折脱位损伤，这一损伤最初见于伐木工人工作时被倒下的树木击伤，由于前方韧带完全破裂，导致潜在的不稳定。
Vertical compression or axial loads in the thoracolumbar junction create compressive loads due to the relatively straight (0°-10° kyphosis) sagittal alignment. Rapid, high-energy, compressive forces can cause rupture of the intervertebral disk through the vertebral endplates, resulting in severe axial loading of the vertebral body and an outward “explosion” of the bony fragments. Denis9 termed this injury a “burst fracture.”
由于胸腰段脊柱相对较“直”（0°-10°的后凸），垂直压缩或者轴向载荷在胸腰段关节局部形成压缩载荷。快速、高能量、压缩应力能通过终板导致椎间盘破裂，并导致严重的轴向载荷以及骨块向外“爆裂”，Denis称之为“爆裂性骨折”。
Shear forces result in disruption of the ligamentous structures, and translation of the superior vertebral body relative to the inferior vertebral body.4 This translation causes a traumatic spondylolisthesis and has a high rate of associated neurologic injury.
剪力导致韧带结构破裂，上位椎体传递至下位椎体，这种传递导致外伤性的脊椎前移，并有极高的神经合并伤。
Flexion-distraction injury mechanisms (seat belt injuries) were first described by Chance.10 In these injuries, the axis of rotation lies anterior to the vertebral column resulting in tensile failure of the spinal column. Such structural failure can occur either through bone, ligament, or combined patterns. These injuries are mechanically unstable, but the pure osseous variant has the potential for healing if reduction can be achieved and maintained.8
Chance首先描述了屈曲－牵张损伤机制（安全带损伤）。在此类损伤中，轴向旋转作用于椎体前方导致脊柱的张力失效。这种结构失效包括骨、韧带或兼而有之。此类损伤为不稳定损伤，但如果是单纯的骨性损伤，良好复位后仍具有愈合的潜力。
The clinical aims of characterizing thoracolumbar injuries are to appreciate the nature of the fracture, to ascertain the presence of instability, and to direct appropriate treatment. A functional definition of stability with respect to spine trauma has evolved, with an increased understanding of the mechanical and pathophysiological elements of spine trauma. Biomechanical stability refers to the mechanical ability of the spine to resist further deformation and abnormal motion and to maintain alignment under clinical loading conditions.2 In addition to the neurologic sequelae of spinal deformation, biomechanical stability is important for the maintenance of posture in the sitting or wheelchair-bound patient.
胸腰段损伤分类的临床目标是理解骨折的自然过程，评估是否存在脊柱不稳，以及选择合适的治疗。就脊柱创伤而言，稳定的功能性的定义需纳入对损伤机制以及病理生理学的进一步的理解。生物力学稳定性是指脊柱避免进一步畸形和异常活动以及在临床载荷条件下保持脊柱对线的能力。除了脊柱的神经功能之外，脊柱的生物力学稳定性对于保持坐姿或轮椅病人是非常重要的。
Both Nicoll’s11 and Holdsworth’s4 original models of injury stressed the importance of the posterior elements, classifying stability on the basis of posterior ligamentous injury (interpreted from interspinous widening). Denis’s development of a 3-column model stressed the importance of the middle column over that of the posterior elements in spinal stability.9 Recent studies have placed a renewed emphasis on the contribution of the posterior ligaments to spinal stability.12-16
Nicoll’s和Holdsworth’s的试验模型均揭示了后侧元件的重要性，将后侧韧带损伤（以椎间增宽为指征）作为区分是否稳定的基础。Denis’s创立了三柱模型强调了中柱对于脊柱稳定的重要性较之后侧元件有过之而无不及。不过最近的研究显示后侧元件对于脊柱稳定具有重要作用。

Classification
分型

Classification systems should facilitate the accurate exchange of information between health care providers and guide in the formulation of a treatment plan. Numerous classification systems have been proposed for thoracolumbar fractures. The nature of these systems has changed over time, with better understanding of the spinal biomechanics as well as improvements in imaging technology. Ideally, a classification system for thoracolumbar fractures should convey the salient information pertaining to spinal stability and neurologic status. A clinical system should be validated and should guide treatment options.
分型系统应便于医务人员精确进行病人信息的交流并指导治疗决策的形成。有大量针对胸腰段骨折的分型系统。随着影像学技术进步以及对生物力学特点理解的深入，这些分型系统逐渐发生了改变。理想的胸腰段骨折分型系统应该能提供直接的脊柱稳定性以及神经功能的信息。一个临床分型系统应是有效并且应该能指导治疗选择。
The earliest fracture classification systems were purely descriptive in nature, listing fractures by the shape seen on radiographic films, such as compression fracture. Although these terms are extensively used, they do little to convey the severity of the individual injury or to direct treatment approaches. Other systems have tried to incorporate biomechanical considerations into a thoracolumbar classification scheme. We review relevant systems used by modern spine surgeons below.
早期的骨折分型系统停留于单纯的描述，根据影像学资料简单列出骨折的形状，例如压缩性骨折。尽管这些方法应用广泛，但这并不能提示个体损伤的严重性或者直接的治疗方法。其他的分型系统则尝试将生物力学纳入分型中。我们回顾目前常用的分型系统如下：

Denis
Denis9 proposed an anatomic classification system based on a 3-column model of the spine. The anterior column is composed of the anterior longitudinal ligament and the anterior half of the vertebral body. The middle column is composed of the posterior half of the vertebral body, the posterior longitudinal ligament, and the posterior annulus fibrosis. The posterior column is composed of the posterior elements, including the facet joints and ligaments. Denis classified fractures based on injury to these columns, and subdivided spine injuries as minor or major, with minor injuries involving the spinous processes, transverse processes, pars interarticularis, and facet joints. Major injuries are classified as compression fractures, burst fractures, seat belt-type injuries, and fracture-dislocations (Fig. 1).
Denis基于三柱模型提出脊柱的解剖学分型。前柱包括前纵韧带、椎体前半部分。中柱包括椎体后半部分、后纵韧带和后侧纤维化环。后柱包括后侧元件，包括关节突和韧带。Denis基于三柱对骨折进行，并进一步细分为轻度或重度。轻度包括棘突、横突、椎弓峡部和关节突。重度包括压缩骨折、爆裂性骨折、安全带骨折和骨折脱位。

AO Classification
AO分型

With improved medical imaging technologies and a better understanding of the injury mechanisms and biomechanics of the spine, there was an increasing recognition that the existing classification systems did not allow for a sufficiently comprehensive method to uniquely characterize the spectrum of spinal injuries. Magerl et al17 and Gertzbein18 applied the AO concepts of fracture classification for extremity fractures to the classification of spine fractures to develop a comprehensive classification system based on what Magerl described as pathomorphological criteria. Three fundamental injury patterns were identified based on the predominant mechanism of injury (Fig. 2).
随着医学影像学的发展以及对于脊柱损伤机制和生物力学理解的深入，大家越来越认识到现有的分型系统无法充分理解脊柱损伤的独特机制。Magerl和Gertzbein应用骨折分型的AO理念对脊柱骨折进行分型，基于损伤的主要机制分出3种主要的类型。

Load Sharing Scoring System
载荷分享评分系统

McCormack et al20 introduced the load sharing scoring system. This work presents not a true classification system but a means of assessing the risk of failure of short segment posterior fixation in thoracolumbar spinal trauma. They retrospectively reviewed their series of thoracolumbar fracture failures after placement of a posterior short segment pedicle screw-plate system. With loss of the structural integrity of the anterior column there is less efficacious load bearing and thus transmission of increased loads to posterior instrumentation. This increased load results in an increased risk of construct failure and progression of deformity. McCormack et al20 identified 3 factors that correlated with failure of posterior short-segment instrumentation: degree of kyphosis correction on lateral film, degree of vertebral body comminution, and fracture fragment apposition. Each factor is graded as mild, moderate, and severe with corresponding point values of 1, 2, and 3, respectively. The summation of these factors yields a total point score ranging from 3 to 9, with a higher score indicating decreased anterior column support. Scores greater than 6 imply that an anterior approach with anterior column support (strut grafting) is indicated.20,21 Inter- and intraobserver reliability has shown high levels of agreement in the assessment of thoracolumbar burst fractures.22 The load-sharing classification system has been demonstrated to successfully identify fractures amenable to either anterior or posterior short-segment fixation, based on fracture comminution,21 and to correlate fracture comminution and displacement with mechanical stability.23,24 However, Scholl et al25 found that the load-sharing classification was not predictive of posterior implant failure. The load-sharing classification does not incorporate any assessment of ligament damage or neurologic injury and, consequently, cannot be used to assess surgical indications. The strengths of the classification system are its being a tool for communicating the structural characteristics of the spinal column following injury and an aid in suggesting fracture patterns not ideally suited to posterior short segment fixation.
McCormack等介绍了载荷分享评分系统（LSSS）。载荷分享评分系统并不是一个真正的分型系统，而是用于评估后路短节段内固定失败的风险。作者回顾了一系列胸腰段骨折采用后路短节段椎弓根钉固定的病例。由于前柱支撑作用的丧失，增加了后侧器械的负荷。这种增加的负荷导致器械失效的风险以及畸形进展的风险增加。McCormack等确定了3种与后路短节段器械失效有关的因素：1、侧位片上后凸畸形矫正的度数2、骨折粉碎的程度3、骨折块分离的程度。每种因素都按轻、中、重分别评为1、2、3分。这些因素的总分为3～9分，分数越高，则行前路手术的必要性越大。超过6分是行前路手术植骨支撑的手术指征。在同一观察者内和不同观察者间，评估胸腰段爆裂性骨折的有效性均显示出高度的一致性。载荷分享评分系统被证实可以基于骨折粉碎程度、相关的骨折粉碎及移位的机械稳定性来鉴别骨折适合于施行前路或者后路短节段固定手术。然而，Scholl等发现载荷分享评分系统不能预测后路器械的失效。载荷分享评分系统没有将韧带破坏或神经损伤纳入评估的考量，因此，不能用于评估手术的指征。这个分型系统的优势在于它可以用于表述外伤后脊柱的结构特征并提示这以骨折类型是否适合于后路短节段固定。

Spine Trauma Study Group––Thoracolumbar Injury Classification and Scoring System (TLICS)
Because of the complexity, suboptimal inter- and intraobserver reproducibility, lack of inclusion of neurologic status, and lack of treatment guidelines associated with earlier classification systems, the Spine Trauma Study Group (STSG) designed a new classification system. Building on previous work, the STSG sought a system that would be more applicable to modern decision-making in the care of thoracolumbar trauma. Part of the goal of this effort was to make a system that was relatively easy to use (based on only a small number of variables) that was easy to communicate that assisted with clinical decision-making that incorporated the most salient突出的 principles used by experienced spine traumatologists in making clinical decisions, and that featured reproducibility in the clinical arena.
由于早期的分型系统较为复杂，缺乏同一观察者内和不同观察者间的可重复性，没有纳入神经功能状态，缺乏治疗指征，基于之前的工作，脊柱创伤研究组（STSG）努力寻找一种能适用于现代胸腰段损伤治疗决策的分型系统。这项努力的部分目的是使分型系统易于使用，以协助脊柱外科医生的临床决策，并增强临床可操作性。
Advances in imaging technology allow improved visualization of soft tissue structures and more accurate identification of ligamentous injuries, particularly, the posterior ligamentous complex (PLC),12 whose integrity is crucial when evaluating fracture stability.26 The importance of the PLC in fracture stability was originally postulated by Nicoll11 and Holdsworth4 and later confirmed with numerous biomechanical studies.
影像技术的进步使得软组织结构可视化并能更精确的鉴别韧带损伤，特别是后侧韧带复合体，对于评价骨折的稳定性具有重要作用。后侧韧带复合体在骨折稳定性中的重要性最初是由Nicoll和Holdsworth提出来的，并随后得到大量生物力学研究的证实。
The Thoracolumbar Injury Classification and Scoring System (TLICS), by Vaccaro et al,27 classifies an injury according to its morphology, the integrity of the PLC, and the neurologic status of the patient. Severity of injury and treatment recommendations are guided by assigning points to the details of these 3 features (Table 1).16 This classification system assigns an injury severity score to a fracture on the basis of 3 components: morphology, integrity of the PLC, and neurologic status of the patient. Injuries are classified by morphology as compression (1 point), or burst (additional 1 point) fracture, translational or rotational injuries (3 points), or distraction injuries (4 points). The PLC is assessed by magnetic resonance imaging (MRI) and classified as intact (0 points), suspected injury (2 points), or confirmed injury (3 points). The patient’s neurologic status is assessed as intact (0 points), nerve root injury (2 points), complete neurologic injury (American Spinal Injury Association [ASIA] A) (2 points), incomplete neurologic injury (ASIA B, C, and D), or cauda equina (3 points). The scores in each category are added to yield the overall severity score, ranging from 1 to 10. Injuries with a severity score of 3 or less are amenable to nonoperative treatment, while injuries with a severity score of 5 or greater likely require surgical intervention. Injuries with a severity score of 4 are indeterminate with regards to the need for surgical intervention, and treatment considerations are generally based on relative factors or clinical qualifiers. An earlier version of the system (Thoracolumbar Injury Severity Score [TLISS]) included mechanism of injury in the classification,27 but a study on the reliability of the system demonstrated that the most interobserver variation was
with respect to classification of injury mechanism.28 Consequently, the TLISS system was modified to eliminate the assessment of points for mechanism and to focus instead on injury morphology.16
由Vaccaro提出的胸腰段损伤分型及评分系统(TLICS)根据后侧韧带复合体的形态学及完整性以及神经功能情况进行分类。根据三个方面的细节特征确定损伤的严重程度以及选择治疗方案。该分型系统确定损伤严重程度分数基于三个方面：形态学，后侧韧带复合体的完整性，病人的神经功能状态。损伤分类形态学为压缩（1分）、爆裂（2分）、平移或旋转伤（3分）、骨折脱位（4分）。通过MRI评估后侧韧带复合体的完整性，完整（0分）、部分损伤（2分）、完全损伤（3分）。神经功能状态完整（0分）、完全损伤（2分）、部分损伤（3分）。评分在3分或以下，适用于保守治疗，评分为5分或以上多采用手术治疗。评分为4分，则可根据其他临床情况决定是否采用手术治疗。该评分系统的早期版本(Thoracolumbar Injury Severity Score [TLISS])原本包括损伤的机制，但是该系统的一项可行性研究表明观察者间变异较大。因此，改良的TLISS系统取消了损伤机制的评分，而改为损伤形态学评分。

While the injury severity score serves as a suggested indicator of injury severity and helps to define the appropriateness of either nonoperative or operative management, it is not a substitute for clinical judgment. In each case, a variety of clinical factors not measured by the classification system including the medical status of the patient and any associated disease states must be considered by the treating physician. These factors, called clinical qualifiers or confounders, may influence the decision to operate, particularly in indeterminate (TLICS score of 4 points) cases. Examples of clinical qualifiers that would increase the need for surgical stabilization would include local marked kyphosis or collapse, open fractures, severe obesity that would preclude bracing, severe closed head injuries, or polytrauma status with the need to mobilize the patient early without major external bracing. Examples of clinical qualifiers that would decrease the success of surgery are major soft tissue injuries or burns at the proposed surgical site, major medical comorbidities, or very poor bone quality making internal fixation of little value.
虽然损伤严重程度评分有助于提示损伤的严重程度以及协助治疗决策，但它并不能完全替代临床决策。对于每一个具体的病例，不能完全依赖分型系统，包括病人的状态以及任何相关疾病的情况都应纳入治疗的考虑。这些因素，称之为临床混杂因素，可能会影响手术决策，特别是对于那些可手术可不手术的病人。能增加手术砝码的因素包括局部显著性的后凸畸形或塌陷、开放性骨折、严重肥胖无法佩戴支具、严重的头颅外伤或多发创伤需要早期活动。能减少手术砝码的因素包括手术部位软组织伤、烧伤、严重合并症、骨质量差无法行内固定。
The TLICS score helps to quantify the type and severity of thoracolumbar injury and the likelihood that simple bracing of the fracture will be unsuccessful. Sound clinical judgment combined with a thorough assessment of the patient should always be used in reaching final treatment decisions.
The TLICS classification system highlights the issues most important in determining the optimal surgical approach in cases requiring operative intervention. By considering the variables used in the TLICS system (injury morphology, integrity of the PLC, and neurologic status), the surgeon can determine which surgical approaches are optimal. For example, the STSG concluded that an anterior approach (corpectomy, fusion, and anterior instrumentation) is the optimal approach if anterior spinal elements are causing major neural compression in the setting of an incomplete neurologic injury and an intact PLC. By contrast, an isolated injury to the PLC leading to instability might be best approached via posterior stabilization. In the setting of both an incomplete neurologic injury with neural element compression and damage to the PLC, a combined anterior and posterior procedure would be optimal. The TLICS scheme should be viewed as one guiding the treating physician to consider the crucial variables that have been found to contribute to mechanical and neurologic stability; it should not be viewed as a rigid scheme that substitutes for clinical judgment in a given case.
胸腰段损伤分型及评分系统有助于量化胸腰段损伤的类型和严重程度。最终的治疗决策需要对病人进行全面的评估后做出可靠的判断。胸腰段损伤分型及评分系统的一大优点在于能确定最佳的手术入路。通过考虑胸腰段损伤分型及评分系统中的各种变量（损伤形态学、后侧韧带复合体的完整性以及神经功能状态），外科医生可以确定最佳的手术入路。例如，脊柱创伤研究组（STSG）确定的前路手术最佳的指征为前侧元件损伤、不完全性神经损伤、后侧韧带复合体完整。相反，如果是后侧韧带复合体的孤立性损伤，则最好采用后侧入路。对于既有前方神经压迫，又有后侧韧带复合体损伤的病例，最好采用前后联合入路。胸腰段损伤分型及评分系统表应被视作指导医生考虑有关机械及神经不稳定的各种重要变量，而不应视为对每一个单个病例做出僵硬治疗决策的依据。

Clinical Usage of Thoracolumbar Classification Systems
胸腰段分型系统的临床应用

Clinically-significant issues addressed in the assessment of thoracolumbar fractures are the neurologic status of the patient and the biomechanical stability of the spinal column. An incomplete neurologic injury is generally recognized as necessitating decompression, by either direct or indirect means. The biomechanical stability of the spinal column directs treatment of the fracture; a stable injury may be amenable to nonoperative treatment, while a biomechanically unstable injury may require surgical treatment. If operative intervention is chosen, it is an understanding of how the fracture displacement and ligamentous injury has affected the stability of the spinal column and possibly encroached on the neural elements that dictates the surgical approach.
评估胸腰段骨折的临床要点是病人的神经功能状况和脊柱的生物力学稳定性。不完全性损伤通常需要通过直接或间接方式减压。脊柱的生物力学稳定性决定骨折的治疗。稳定性损伤适合于非手术治疗，生物力学不稳定性损伤则通常需要手术治疗。如果选择手术干预，理解骨折移位及韧带损伤如何影响脊柱的稳定性以及神经占位情况决定着手术的入路选择。
At initial presentation, a computed tomography (CT) scan should be obtained to evaluate all thoracolumbar fractures, as plain radiographs alone have a high rate of missed diagnosis of posterior vertebral body injury.29 A vertebral collapse of greater than 50% on x-ray is highly suggestive of posterior column disruption and increased risk of progressive deformity.5 An MRI of the injured region may be helpful to assess the status of the PLC and to determine the presence or absence of compression of the neurologic elements.
初期应应用CT扫描评估所有的胸腰段骨折，平片容易露诊后侧椎体损伤。X线片上椎体塌陷超过50％高度提示后柱破裂，进展性后凸畸形的风险增加。损伤节段的MRI有助于评估后侧韧带复合体的情况，并能判断是否存在神经元件的压缩。
All the classification systems presented earlier have components that aid in clinical considerations, but none except the TLICS system has been validated as a system inclusive of all these factors. The TLICS has incorporated neurologic status as a key component in the classification of thoracolumbar fractures, and is the first system to propose defined treatment algorithms based on injury classification. The load-sharing classification system has demonstrated success in assessing the structural integrity of the spinal column and applying that information to the clinical decision of what type of construct to use for spinal instrumentation of a fracture. Both the TLICS and load-sharing classification schema have drawn on the relative strengths of earlier classification systems.
所有较早期的分型系统均包含了有助于临床决策的元素，但只有胸腰段损伤分型及评分系统被证实包含所有这些元素，且行之有效的。胸腰段损伤分型及评分系统融入了神经功能状况这个关键因素，也是第一个根据损伤的分类确定治疗方案的分型系统。载荷分享分型系统成功用于评估脊柱的结构完整性以及提供针对某种骨折选取何种内固定物的临床决策信息。以上两种分型系统与较早期的分型系统相比，均能提供相对更有效的信息。

Conclusions
结论

The thoracolumbar spine is uniquely predisposed to traumatic injury and subsequent instability. The complex anatomy and mechanical forces acting on the region produce many unique fracture patterns. Identifying the basic characteristics of an injury, and how those characteristics will affect clinical management, should be the aim of clinical classification systems.
胸腰段易罹患损伤及后继不稳定。复杂的解剖及应力机制造成了该区域独特的骨折类型。鉴别损伤的基本特征，以及这些特征如何影响临床决策，是临床分型系统的目标。
Proposed classification schemes have sought to incorporate various aspects of the available data on individual thoracolumbar fractures. An increased understanding of the biomechanics of spinal column injuries coupled with increased anatomic information via imaging studies has resulted in an increase in the scope and complexity of proposed classification systems. The observed moderate inter- and intraobserver agreement with several of these classification systems suggests that attempts to make the classification schema all-inclusive have resulted in schemes that are too cumbersome and are of limited clinical utility.
已有的分型系统融合了胸腰段骨折的多方面的有效信息。随着对脊柱生物力学理解的深入以及解剖影像学信息的增加使得分型系统更趋复杂。这些分型系统在同一观察者内和不同观察者间的中度的一致性表明尝试使分型表包括所有信息是繁琐而不切实际的，且将限制其临床应用。
More recent classification algorithms (TLICS, TLISS, load-sharing) have sought to identify a subset of key salient features to guide the management of these complicated fracture patterns. While long-term clinical data are needed to validate the clinical applicability of these systems, the process by which these systems were developed is illustrative of the issues (biomechanical stability, neurologic status, need for surgery, preferred surgical technique, and long-term prognosis) that should be considered by the physician caring for a patient with traumatic spinal column injury.
近来的分型系统(TLICS, TLISS, load-sharing)尝试通过鉴别各种显著特征以指导处理这些复杂的骨折类型。需长期的临床资料来确定这些分型系统的有效性，外科医生在处理脊柱外伤时应详细考虑这些分型系统所包括的各种信息内容（生物力学稳定性、神经功能状况、是否需要手术、手术技术以及长期疗效）。

References
1.Stagnara P, De Mauroy JC, Dran G, et al: Reciprocal angulation of vertebral bodies in a sagittal plane: approach to references for the evaluation of kyphosis and lordosis. Spine 7:335-342, 1982
2.White AA 3rd, Panjabi MM: The basic kinematics of the human spine. A review of past and current knowledge. Spine 3:12-20, 1978
3.Panjabi MM, Brand RA Jr, White AA 3rd: Three-dimensional flexibility and stiffness properties of the human thoracic spine. J Biomech 9:185-192, 1976
4.Holdsworth F: Fractures, dislocations, and fracture-dislocations of the spine. J Bone Joint Surg Am 52:1534-1551, 1970
5.Weitzman G: Treatment of stable thoracolumbar spine compression fractures by early ambulation. Clin Orthop Relat Res 76:116-122, 1971
6.Denis F, Burkus JK: Shear fracture-dislocations of the thoracic and lumbar spine associated with forceful hyperextension (lumberjack paraplegia). Spine 17:156-161, 1992
7.Burke DC: Hyperextension injuries of the spine. J Bone Joint Surg Br 53:3-12, 1971
8.Browner BD, Jupiter JB, Levine AM, et al (eds): Skeletal Trauma: Basic Science, Management, and Reconstruction. Philadelphia, PA, WB Saunders, 2003
9.Denis F: The three column spine and its significance in the classification of acute thoracolumbar spinal injuries. Spine 8:817-831, 1983
10.Chance G: Note on a type of flexion fracture of the spine. Br J Radiol 21:452-453, 1948
11.Nicoll E: Fractures of the dorso-lumbar spine. J Bone Joint Surg Br 31:376-394, 1949
12.Lee HM, Kim HS, Kim DJ, et al: Reliability of magnetic resonance imaging in detecting posterior ligament complex injury in thoracolum-bar spinal fractures. Spine 25:2079-2084, 2000
13.Lee JY, Vaccaro AR, Lim MR, et al: Thoracolumbar injury classification and severity score: a new paradigm for the treatment of thoracolumbar spine trauma. J Orthop Sci 10:671-675, 2005
14.Vaccaro AR, Kim DH, Brodke DS, et al: Diagnosis and management of thoracolumbar spine fractures. Instr Course Lect 53:359-373, 2004
15.Vaccaro AR, Lee JY, Schweitzer KM Jr, et al: Assessment of injury to the posterior ligamentous complex in thoracolumbar spine trauma. Spine J 6:524-528, 2006
16.Vaccaro AR, Lehman RA Jr, Hurlbert RJ, et al: A new classification of thoracolumbar injuries: the importance of injury morphology, the integrity of the posterior ligamentous complex, and neurologic status. Spine 30:2325-2333, 2005
17.Magerl F, Aebi M, Gertzbein SD, et al: A comprehensive classification of thoracic and lumbar injuries. Eur Spine J 3:184-201, 1994
18.Gertzbein SD: Spine update. Classification of thoracic and lumbar fractures. Spine 19:626-628, 1994
19.Wood KB, Khanna G, Vaccaro AR, et al: Assessment of two thoraco-lumbar fracture classification systems as used by multiple surgeons. J Bone Joint Surg Am 87:1423-1429, 2005
20.McCormack T, Karaikovic E, Gaines RW: The load sharing classification of spine fractures. Spine 19:1741-1744, 1994
21.Parker JW, Lane JR, Karaikovic EE, et al: Successful short-segment instrumentation and fusion for thoracolumbar spine fractures: a consecutive 41/2-year series. Spine 25:1157-1170, 2000
22.Dai LY, Jin WJ: Interobserver and intraobserver reliability in the load sharing classification of the assessment of thoracolumbar burst fractures. Spine 30:354-358, 2005
23.Aligizakis A, Katonis P, Stergiopoulos K, et al: Functional outcome of burst fractures of the thoracolumbar spine managed non-operatively, with early ambulation, evaluated using the load sharing classification. Acta Orthop Belg 68:279-287, 2002
24.Wang XY, Dai LY, Xu HZ, et al: The load-sharing classification of thoracolumbar fractures: an in vitro biomechanical validation. Spine 32:1214-1219, 2007
25.Scholl BM, Theiss SM, Kirkpatrick JS: Short segment fixation of thora-columbar burst fractures. Orthopedics 29:703-708, 2006
26.James KS, Wenger KH, Schlegel JD, et al: Biomechanical evaluation of the stability of thoracolumbar burst fractures. Spine 19:1731-1740, 1994
27.Vaccaro AR, Zeiller SC, Hulbert RJ, et al: The thoracolumbar injury severity score: a proposed treatment algorithm. J Spinal Disord Tech 18:209-215, 2005
28.Vaccaro AR, Baron EM, Sanfilippo J, et al: Reliability of a novel classification system for thoracolumbar injuries: the Thoracolumbar Injury Severity Score. Spine 31:S62-S69, 2006; discussion S104
29.Ballock RT, Mackersie R, Abitbol JJ, et al: Can burst fractures be predicted from plain radiographs? J Bone Joint Surg Br 74:147-150, 1992