股骨近端骨折影像学改变和动力学特性
From the Department of Radiology, Division of Emergency Radiology , and Department of Orthopedic Surgery (M.J.W.), Brigham and Women’s Hospital, Harvard Medical School■讨论解剖、形态特征和成人股骨近端骨折的损伤机制。■不同类型的股骨近端骨折合适的成像后处理。■列出了这些骨折的潜在的并发症和相应的管理策略。正常解剖与生物力学动画1计算机生成动画演示臀部的相关功能解剖。
图1股骨近端的后方面的计算机生成的图像展示了正常的解剖标志和伤害的区域，股骨头（红色）和颈部（黄色）是囊内，转子间（蓝色）和转子（橙色）区域是囊外。GT =大转子，LT =小粗隆， PF =梨状肌窝，* =关节囊。
图2计算机生成的图像表明了股骨近端的承重骨小梁的走向，包括垂直取向的主承重小梁（红色线）、水平定向的主拉伸小梁（黑线）、倾斜取向二次压缩小梁（黄线）。内侧会聚压缩小梁之间的居间骨小梁被称为沃德三角形（黄色三角形），相对薄弱的部位。
图3计算机生成的图像表明股骨近端的血管解剖。血液流动到股骨近端主要由内侧和外侧旋股动脉的分支供给。补充流股骨头通过的圆韧带，闭孔动脉分支的动脉供应。绿色椭圆=的囊外和颈升动脉retinacular囊内部分之间的过渡点; 黄圈=股骨头颈交界处的外侧面，是受伤造成临床显著血管重大危险脆弱的区域。股骨头颈交界处的侧缘是至关重要的，因为这是横向骨骺血管的最常见的切入点，在这里骨折，血管损伤具有很高风险囊内骨折动画2电脑动画模拟正面碰撞汽车，碰撞过程中演示了外伤性后髋关节脱位的高能机制。
图4计算机生成图像演示髋关节后脱位过程中，受伤机制的作用力特性。随着髋关节的屈曲，内收和内旋的增加，股骨的轴向负载（黄色箭头）更可能导致股骨头经过相对窄的前后髋臼壁（黄线）的平移，而不导致股骨头骨折 ，但具有可能的髋臼壁骨折。具有较小程度的屈曲，内收和内旋转（红色箭头）的轴向负荷，更可能导致股骨头的骨折脱位而没有髋臼骨折，这是由于股骨头撞击在骨盆后柱的强骨（红色椭圆形）。中间屈曲度，内收，和内部旋转可导致严重性混合股骨头或髋臼骨折。
图5A-D计算机生成的图像演示股骨头骨折皮普分类系统。（一） 1型骨折局限于股骨头中央凹。（二） 2型骨折延伸中央凹和圆韧带，圆韧带附着到骨折碎片。（三） 3型病变合并1型或2股骨头骨折与股骨颈骨折。（四）第4类病变合并1型或2股骨头骨折的髋臼骨折。
图6a-c 28岁男性，在髋关节后脱位之后形成的Pipkin 2型骨折，前后位片（a）和冠状面计算机断层摄影（CT）图像（b）显示大的、移位的关节内骨折碎片 ，其带着圆韧带随后翻转，导致闭合复位不足。放射摄影术隐匿的继发性关节内骨折碎片，在CT图像上显示明确。（c）在手术后获得的X线片显示了翻转骨片（箭头）被螺钉固定，以及在开放复位期间诱导的转子截骨术骨片的螺钉固定。
图7a-b（a）一个56岁男性，右髋关节冠状 STIR MR图像，患者主诉急性髋关节疼痛，MRI显示大面积的高信号水肿区，低信号显示软骨下骨折线（箭头），其相对于关节表面呈凹形。 （b）在接受慢性皮质类固醇治疗的62岁男性中的AVN。 在右髋的冠状中等加权脂肪饱和MR图像上，在低信号损伤边缘（箭头）上没有看到高信号水肿，这表明慢性缺血的骨。软骨下不全性骨折在组织学上与骨坏死不同，因为前者主要由骨折愈伤组织和具有骨髓水肿的肉芽组织组成，和近端增强及远端骨折线，这些与在骨坏死中看到的血管化，非增生近端表浅骨相反。头下型股骨颈骨折动画3 计算机生成动画演示头下型股骨颈骨折之后从站在高处跌落低能机制，对大转子横向冲击。
股骨颈骨折的高能机制。 计算机生成的图像显示了从较高的地方跌落，作用力作用到屈曲和外展的膝盖上，负载力（黄色箭头）通过股骨（红色箭头）的轴向的向上传输，导致股骨颈的牵引和剪切断裂。 强后髋臼柱稳定股骨头在髋臼内。 红色星暴=冲击面积。
图9a-d 计算机生成的图像说明了还原头下型股骨颈骨折分类系统。（a）第一阶段骨折是头下骨折，其可以是不完整的或外翻。（b）第二阶段是完全骨折，但头下骨折无移位。（c）第三阶段骨折是部分移位的完整的头下骨折。（d）第四阶段骨折是完全移位的头下型骨折。
图10计算机生成的图像说明了由骨折相对于水平面（虚线白线）的角度确定的股骨颈骨折的Pauwels分类系统。 骨折可以表现出高达30°（度1），30°-50°（度2）或大于50°（度3）的角度。
图11 91岁的女性，髋关节正位X光片显示头下型股骨颈骨折，断端分离（箭头）
图12a-c 外翻和内翻冲击性头下骨折。（a）88岁女性的正位片显示了近端骨折特征性外翻角，这是由于外侧股骨颈和股骨头存在微小皮质重叠， 形成三角形不透明区（箭头）。（b）一位66岁的女性臀部的前后放射照片显示了内翻 - 受影响的骨折，根据存在的三角不透明度可以将其与更常见的外翻角变形区分开来 代表内侧皮层重叠（小箭头），以及移位的侧面皮层骨折（大箭头）。（c）一个68岁女性的髋关节的冠状CT图像显示了内侧皮层重叠（三角不透明度[小箭头]）的内翻 - 冲击性骨折，以及突出的，下方突出的皮层边缘，发现 经常被误认为是一个骨赘（蘑菇帽变形）（大箭头）。
图13a-b一名70岁的男性患者发生跌倒,左股骨颈骨折。（a）在前后X线照片， 没有明显的皮质骨折线和没有特征性皮层重叠的证据。（b）急诊髋关节MR成像的冠状T1加权图像显示低强度断裂线（箭头），周围可见低信号水肿面积较大。
图14a-b一位58岁男性Pauwels 3型股骨颈骨折。（a）左前髋的前后放射线照片显示了相对于水平面大约70°取向的断裂线（箭头）。 病人接受动力髋螺钉固定。（b）前后放射照片显示硬件布置。 然而，尽管进行螺钉固定，但是患者发展AVN并且随后需要THA。
图15计算机生成的图像显示了股骨颈应力骨折的位置和力的动力学。股骨颈相对于骨骼轴向承载轴线（绿色箭头）的横向位置产生导致内侧皮质（黄色箭头）压缩和外侧皮质（橙色箭头）分散的内翻弯曲力矩。强的臀中肌（蓝色箭头）的收缩抵消这些力，而臀中肌肌肉疲劳允许相对无对抗的骨神经微创伤，其可以产生内侧的疲劳型应激性骨折，或者更不常见地产生外侧皮质骨折（红色线）。
图16a-b一个85岁妇女的图像，以骨质疏松症和腹股沟疼痛为主诉。（a）初始正位X线片显示外侧股骨皮质（白色箭头）的局部中断，其断裂线垂直于原发性拉伸小梁（黑色箭头）。 患者被诊断为不完全性应激性不全型骨折，并严格限制活动。（b）在急性无创伤性腹股沟疼痛加重之后，随访X线片显示现在移位的股骨颈骨折（箭头）。
图17a-b（a）54岁女性的右髋前后放射照片，有慢性髋关节和腹股沟疼痛的主诉，显示病区三角形（箭头）区域的微小的骨膜反应和中间骨皮质增厚。（b）随后STIR MR冠状图像显示通过叠加在高信号水肿区域（箭头）上的内侧股骨皮层的低信号应力骨折线。囊外骨折
图18C计算机生成的图像说明了股骨粗隆间骨折Evans分型（由Jensen修改）。（a）1型骨折是无位移的骨折。 （b）2型骨折是具有位移的骨折。（c）3型骨折是具有后外侧皮质粉碎的三部分骨折。 （d）4型骨折是具有后内侧皮质粉碎的三部分骨折。 （e）5型骨折包括四个或更多个部分，具有内侧和外侧皮质粉碎。 （f）反向倾斜骨折是一种主要的变体，从内侧转子间皮层向下延伸到转子下皮层。
图19a-c 65岁至80岁之间妇女的各种形态特征的转子间骨折。（a）前后放射照片显示1型骨折，可见延伸穿过外侧和内侧皮质（箭头）的非移位骨折线。（b）另一个患者前后放射照片显示中度移位，但机械稳定性还可以（箭头）的2型骨折。（c）在第三个患者的前后放射照片显示更严重的5型骨折，伴随着后内侧（小箭头）和后外侧（大箭头）骨皮质的粉碎，这表明高度不稳定的损伤。
图20髋关节的计算机生成的图像，显示了在Evans-Jensen 2型转子间骨折（绿线）与逆倾斜骨折（红线）的状态下，盆腔肌肉组织作用的减少或分散。 强内收肌肌肉的内侧股骨插入，远离内侧皮质骨折线边缘，这在2型骨折的情况下，会导致后续减少内收（黄色箭头），断裂碎片与臀中肌和臀小肌的外展一起作用（绿色箭头），导致相对断裂稳定性。在反向倾斜性骨折中，其强大的内收肌和臀肌产生远端骨折块的净内侧移位。
图22a-b 一名54岁的患者，股骨粗隆间骨折，该患者从站立位摔倒。 （a）初始前后X线片显示无骨折的证据。 MR成像用以急诊评估隐匿性骨折。 （b）右髋的冠状T1加权MR图像显示包括在梨状窝附近的大转子的内侧皮质的低信号断裂线，并且向内侧延伸到股骨内侧皮质（箭头）。
图23一名73岁的男性患者孤立性的小转子骨折，该病人是前列腺癌弥漫性硬化骨转移性患者，出现急性发作性大腿疼痛。 右髋的前后放射照片显示小转子的明显孤立性骨折（箭头）。
图24计算机生成的图像显示了转子下股骨骨折Russell-Taylor 分类系统。1A型骨折发生在涉及外侧和内侧股骨转子间股骨区域内，但它们可以影响梨状窝和小转子（绿色）。1B型骨折与1A型骨折相似，具有单独的小转子骨折碎片（红线）。2A型骨折涉及梨状肌窝，潜在的入口点为髓内杆的位置，并延伸到转子下股骨内侧（绿色和黄色）。2B型骨折类似于2A型骨折，但类似1B型骨折，包括单独的小转子骨折碎片。
图25 计算机生成图像演示离心力施加在关键的肌肉，插入到股骨粗隆下骨折碎片。大转子骨片被强的臀中肌和臀小肌（黄色箭头）牵拉横向成角度； 小转子骨片由髂腰肌肌肉（绿色箭头）前内侧移位和外旋； 并且远端股骨碎片被内收肌肌肉系统（橙色箭头）牵拉并内移位。
图26a-b 一个84岁的女性，在跌倒后主诉髋关节疼痛，X线片显示1B型转子间骨折。随后进行内固定。
图27a-b 接受双膦酸盐治疗的65岁女性患者的非典型小结节性骨折。 患者最初因为大腿疼痛前去急诊科就诊。免责声明：部分内容源自互联网和其他公众平台，仅供阅者浏览或参考，不确保准确性。如有侵犯版权请告知，我们将及时删除。如果您自行使用本账号发布的信息发生了损失或损害，本账号不负任何法律责任。您浏览本站发布的内容，您的浏览行为将被视为对本声明全部内容的认可。
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