Acetabular fractures revisited: part 2, a new CT-based classification

OBJECTIVE: The objective of this investigation was to provide a new CT-based classification of acetabular fractures. MATERIALS AND METHODS: The axial CT scans of 112 randomly selected acetabular fractures in patients admitted to a level 1 trauma center between January 1998 and December 2000 were analyzed by an experienced orthopedic trauma surgeon and two experienced emergency radiologists. When available, 3D reformatted images were analyzed as well. The fracture pattern for each acetabular fracture, with respect to column walls and extension beyond the acetabulum, when present, was recorded. Fracture comminution was not a defining characteristic. RESULTS: Analysis of the 112 acetabular fracture patterns showed that each fracture fell into one of four broad categories. Category 0 included wall fractures only. Category I included acetabular fractures limited to a single (anterior or posterior) column. Category II fractures included those involving both the anterior and posterior columns; category II fractures were further subdivided into those with no fracture extension beyond the acetabulum, those with superior or inferior extension, and those with both superior and inferior extensions beyond the acetabulum. Category III fractures included only the "floating" acetabulum, which is defined as an acetabular fracture in which the acetabulum is separated from the axial skeleton both anteriorly and posteriorly. CONCLUSION: The axial CT display of acetabular fracture patterns provides a basis for a classification of acetabular fractures that is simple, unambiguous, readily understood by both radiologists and orthopedic surgeons and provides clear direction for both diagnosis and surgical treatment planning. Category and subcategory fracture specificity creates a mechanism for intra- and interdepartmental postoperative assessment of any of the individual acetabular fracture types.     

Acetabular fractures revisited: part 1, redefinition of the Letournel anterior column

OBJECTIVE: The objective of part 1 of this study is to redefine the Letournel anterior column on the basis of developmental and adult pelvic skeletal anatomy. MATERIALS AND METHODS: The axial CT scans of 112 randomly selected patients with acetabular fracture or fracture-dislocations admitted to a level I trauma center between January 1998 and December 2000 were analyzed by an experienced orthopedic trauma surgeon and two experienced emergency radiologists. When available, 3D reformatted images were analyzed as well. The discrepancy between the Letournel definition of the anterior and posterior columns became readily apparent. Standard text books of anatomy and surgical anatomy were referenced relative to the embryologic and adult components of the acetabulum. RESULTS: The anterior column is redefined with its superior border being the anatomic arcuate and iliopectineal lines, thereby coinciding with the superior border (arcuate line) of the Letournel posterior column. CONCLUSION: Redefinition of the anterior column eliminates diagnostic ambiguity of the Letournel elementary anterior column fracture as well as the Letournel associated anterior column or wall with hemitransverse fracture. The redefined anterior column is integral to the CT-based classification described in part 2 of our study.     

Normal acetabular anatomy for acetabular fracture assessment: CT and plain film correlation

The computed tomographic (CT) and conventional radiographic appearances of the acetabulum are correlated for assessment of acetabular fractures according to the Judet and Letournel classification system, a system widely used by orthopedic surgeons performing fracture reduction and external fixation of the acetabulum. A desiccated pelvis was marked along the acetabular borders with lead solder, and anteroposterior (AP) and oblique radiographs were obtained. The solder was then replaced by barium-impregnated string, and the acetabulum was scanned by CT. Radiographic-CT correlations of acetabular landmarks should aid the orthopedist by providing a useful interpretation of acetabular fractures according to the Judet and Letournel system.     

Evaluation of acetabular fractures with two- and three-dimensional CT.

The authors applied a widely used radiographic system of classifying acetabular fractures to axial computed tomographic (CT) scans and three-dimensional reconstructions in over 100 cases. In the classification system, fractures are analyzed according to the extent of involvement of two acetabular columns--the posterior and the anterior. To provide a better understanding of the CT anatomy of the acetabulum, the authors defined the boundaries of the columns on axial CT scans. They illustrated the most common fractures (posterior wall, transverse, transverse with posterior wall, and both columns) with radiographs, axial CT scans, and three-dimensional reconstructions. Axial CT scans readily demonstrated the fractures and presence of intraarticular fragments. Three-dimensional images helped in understanding the precise plane of the fracture, the degree of disruption of the articular surface, and spatial relationships of fragments. Although present three-dimensional CT is not without limitations, the authors believe that the technique is valuable and that, in their experience, it has facilitated preoperative planning.     

3D CT versus axial helical CT versus conventional tomography in the classification of acetabular fractures: a ROC analysis

AIM: To assess the diagnostic power of three-dimensional computed tomography (3D CT), axial helical computed tomography (CT) and conventional tomography in the classification of acetabular fractures by interdisciplinary review. MATERIALS AND METHODS: Receiver operating characteristics (ROCs) were assessed for two radiologists and two surgeons blinded to the presence of acetabular fractures in an animal model (a total of 62 porcine hips, 40 of them with artificial acetabular fractures). Main target parameter was the diagnostic accuracy in the classification of the artificial fractures following Judet et al. RESULTS: ROC analysis for radiologists showed A(z) values of 0.83 for 3D CT, 0.81 for axial helical CT, and 0.78 for conventional tomography; differences between the three techniques were not significant (P = 0.46-0.73). A(z) values for the surgeons were 0.87 for 3D CT, 0.68 for axial helical CT, and 0.60 for conventional tomography; 3D CT was significantly better than axial helical CT (P = 0.01) and conventional tomography (P = 0.001). The differences between axial helical CT and conventional tomography were not significant (P = 0.37). CONCLUSION: Acetabular fractures are best classified by 3D CT, followed by axial helical CT and conventional tomography when assessed by surgeons. 3D CT did not provide any additional significant benefit in the classification performed by radiologists.     

眼眶骨折常规体位CT加直接倾斜矢状面的研究：附120例分析

目的：探讨直接倾斜矢状面ＣＴ在眼眶骨折中的应用价值。材料与方法：１２０例眼眶外伤患者，在常规横断面及冠状面ＣＴ的基础上加扫直接倾斜矢状面ＣＴ，比较观察各体位显示的信息。结果：１２０例眼眶骨折中，上下壁骨折冠状面显示１０３例，矢状面显示１０５例；横断面未能显示。上下直肌增粗冠状面显示５０例，矢状面显示７２例；视神经弯曲２７例均矢状面显示。结论：直接倾斜矢状面ＣＴ能更全面地观察眼眶上下壁的情况及上下直     

髋关节外伤螺旋CT重建技术的应用

目的：探讨螺旋CT多平面重建(MPR)、三维表面遮盖法重建(SSE))及容积再现(VR)在髋臼骨折及股骨头脱位中的临床应用价值。方法：对25例髋关节外伤的患者进行螺旋CT容积扫描，然后在工作站上进行MPR、SSD、VR成像，结合轴位扫描图像，观察这三种重建图像在显示骨折线、骨碎片以及股骨头脱位方向和程度的效果。结果：MPR对判断股骨头的脱位方向和程度有帮助；SSD显示髋臼骨折和股骨头脱位的立体效果较好；VR虽然立体效果稍逊于SSD．但能显示骨折的细微结构。结论：MPR、SSD、VR三种重建方法可互为补充，能够立体直观、整体地显示髋臼骨折和股骨头脱位．为决定治疗方案和选择适当的手术入路提供了依据.     

Acetabular stress fractures in military endurance athletes and recruits: incidence and MRI and scintigraphic findings

OBJECTIVE: To evaluate the incidence and the MRI and scintigraphic appearance of acetabular stress (fatigue) fractures in military endurance athletes and recruits. DESIGN AND PATIENTS: One hundred and seventy-eight active duty military endurance trainees with a history of activity-related hip pain were evaluated by both MRI and bone scan over a 2-year period. Patients in the study ranged in age from 17 to 45 years. They had hip pain related to activity and had plain radiographs of the hip and pelvis that were interpreted as normal or equivocal. The study was originally designed to evaluate the MRI and scintigraphic appearance of femoral neck stress fractures. Patients had scintigraphy and a limited MRI examination (coronal imaging only) within 48 h of the bone scan. Twelve patients demonstrated imaging findings compatible with acetabular stress fractures. RESULTS: Stress fractures are common in endurance athletes and in military populations; however, stress fracture of the acetabulum is uncommon. Twelve of 178 patients (6.7%) in our study had imaging findings consistent with acetabular stress fractures. Two patterns were identified. Seven of the 12 (58%) patients had acetabular roof stress fractures. In this group, two cases of bilateral acetabular roof stress fractures were identified, one with a synchronous tensile sided femoral neck stress fracture. The remaining five of 12 (42%) patients had anterior column stress fractures, rarely occurring in isolation, and almost always occurring with inferior pubic ramus stress fracture (4 of 5, or 80%). One case of bilateral anterior column stress fractures was identified without additional sites of injury. CONCLUSIONS: Stress fractures are commonplace in military populations, especially endurance trainees. Acetabular stress fractures are rare and therefore unrecognized, but do occur and may be a cause for activity-related hip pain in a small percentage of military endurance athletes and recruits.     

螺旋CT三维和多平面重建在髋臼骨折中的应用

目的：探讨螺旋CT三维（3D）和多平面重建（MPR）在髋臼骨折中的临床应用价值。方法：27例髋臼骨折的病人先经营骨盆螺旋CT薄层扫描，并在工作站上作髋臼三维和多平面重建。注重观察髋臼骨折的以及CT表现特征。结果：27例病人共计31个髋臼骨折。除1个T形骨折用三维和多平面重建判断为横行骨折外，其余30个骨折轴位CT、三给和多平面重建均显示。三维和多平面重建能更直观的显示病变的具体情况。结论“螺旋CT三维和多平面重建是轴位CT扫描的有价值的补充手段，在髋臼骨折中有很高的应用价值。     

螺旋CT三维及四维成像在髋臼骨折中的应用

目的：探讨髋臼骨折中三维及四维CT重建技术的方法及临床应用价值。方法：32例髋臼骨折患者进行螺旋CT扫描，并通过多平重建法（MPR），三维表面遮盖法（SSD）及容积重建技术（VRT）观察损伤细节，对骨折进行临床分型。其中11例术后进行内固定复位及关节置换的疗效观察。结果：32例中MPR，SSD显示骨折28例，有4例未显示全部骨折线；SSD显示骨折立体效果优于VRT，对明显移位旋转的骨折显示清晰。VRT显示全部骨折，且在显示骨折细微结构和无移位骨折方面优于SSD，并可立体直观显示术后固定位置及复位效果。结论：螺旋CT，MPR，SSDVRT技术是诊断髋臼骨折的有效手段，对诊断复杂性髋臼骨折应作为首选，VRT技术对髋臼骨折手术方案制定及术手疗效判断有较高的价值。     

螺旋CT三维重建(SSD、VRT)在髋臼骨折中的临床诊断价值:兼与X线、2DCT、MPR比较

目的　探讨螺旋CT三维表面遮盖法重建 (SSD)及容积重建技术 (VRT)显示髋臼骨折的诊断价值。方法　使用SIEMENSPLUS4螺旋CT机对 3 0例髋臼损伤患者进行扫描 ,在SIEMENS工作站进行SSD及VRT重建观察损伤细节 ,并与X线平片、二维CT(2DCT)、MPR比较。结果　 3 0例髋臼骨折 ,2DCT、MPR、VRT检查共发现了 169处骨折 ,X线发现 13 3处骨折 ,检出率是 78.7%。SSD发现 15 8处 ,检出率 93 .5 %。根据 2DCT扫描结果 ,经统计学分析 ,SSD、VRT检出骨折创伤量与X线、2DCT、MPR三者无显著性差异。3 0例髋臼骨折根据 2DCT按AO分类法分类 ,并经MPR、3DCT重建证实其分类 ,其中 2 2例经手术确诊 ,X线误诊 7例。 3DCT获得了髋臼骨折最直观、全面的图像。 12例进行了术后的 3DCT重建 ,VRT立体显示手术后骨盆及内固定物的形态、结构 ,SSD重建有时不能分辨内固定物和骨盆的形态、结构。结论　螺旋CTSSD及VRT是诊断髋臼骨折的有效手段 ,3DCT在骨盆及髋臼骨折分型中有重要的作用 ,对复杂性髋臼骨折的诊断应作为首选。VRT对术后固定针的位置及复位效果的判断有较高的价值     

Ⅰ期全髋关节置换治疗髋臼骨折

目的 探讨髋臼骨折后Ⅰ期全髋关节置换(total hip arthroplasty,THA)的手术适应证和手术方法,观察其临床疗效.方法 对11例髋臼骨折患者行Ⅰ期THA.其中前柱骨折3例,后壁骨折1例,后柱骨折2例,后柱合并后壁骨折2例,横形骨折1例,横形合并后壁骨折1例,两柱骨折1例.伤后8～37 d(平均24 d)接受THA.对新鲜髋臼骨折患者,先用重建钢板或螺钉固定骨折以恢复髋臼肇的形态,将切下的股骨头制成颗粒状或块状植于髋臼内后安置臼杯.陈旧性髋臼骨折有节段性髋臼骨缺损者,将切下的股骨头制成大块状进行髋臼内结构性植骨后再安置臼杯.结果 术后3个月完全负重,无人工关节脱位.随访时间6～45个月,平均28个月.Harris评分平均78分.髋关节屈伸平均活动度为95°.X线片示1例出现髋臼松动及骨溶解征象.结论 髋臼骨折移位明显,关节软骨面损伤严重,错过了手术复位时机,可以Ⅰ期行THA.如能创造稳定的髋臼杯结构,近期临床效果满意.     

多层螺旋CT多平面重建及三维重建在复杂髋臼骨折中的临床价值

目的：探讨多层螺旋CT三维重建及多平面重建在复杂髋臼骨折中的临床价值。方法：回顾性分析36例复杂髋臼骨折的MPR、SSD、VR表现。结果：MPR、SSD、VR均显示了36例复杂髋臼骨折及16例股骨头脱位,MPR、SSD、VR还分别显示了骨盆其他骨骨折51、43、46处,MPR及VR显示了SSD没显示的髋关节内碎骨片1例。MPR在显示髋臼骨折线的方向、数量上较SSD、VR理想,SSD、VR图像立体感强,空间位置明确,对复杂髋臼骨折的分类及判断股骨头脱位的方向和距离较MPR好。结论：多层螺旋CT3D图像结合MPR及横断面图像,能立体直观地显示复杂髋臼骨折及关节脱位的空间位置,协助临床诊断和治疗。     

Missed rib fractures on evaluation of initial chest CT for trauma patients: pattern analysis and diagnostic value of coronal multiplanar reconstruction images with multidetector row CT

Objective The objective of this study was to review the prevalence and radiological features of rib fractures missed on initial chest CT evaluation, and to examine the diagnostic value of additional coronal images in a large series of trauma patients. Methods 130 patients who presented to an emergency room for blunt chest trauma underwent multidetector row CT of the thorax within the first hour during their stay, and had follow-up CT or bone scans as diagnostic gold standards. Images were evaluated on two separate occasions: once with axial images and once with both axial and coronal images. The detection rates of missed rib fractures were compared between readings using a non-parametric method of clustered data. In the cases of missed rib fractures, the shapes, locations and associated fractures were evaluated. Results 58 rib fractures were missed with axial images only and 52 were missed with both axial and coronal images (p=0.088). The most common shape of missed rib fractures was buckled (56.9%), and the anterior arc (55.2%) was most commonly involved. 21 (36.2%) missed rib fractures had combined fractures on the same ribs, and 38 (65.5%) were accompanied by fracture on neighbouring ribs. Conclusion Missed rib fractures are not uncommon, and radiologists should be familiar with buckle fractures, which are frequently missed. Additional coronal imagescan be helpful in the diagnosis of rib fractures that are not seen on axial images.     

Diagnosis of pelvic fractures in patients with acute pelvic trauma: efficacy of plain radiographs.

Although CT is widely recognized as an important adjunct to plain films in the evaluation of patients with acute pelvic trauma, accurate diagnosis of orthopedic injuries with plain films alone is often important to determine if immediate external fixation is necessary. The purpose of this study was to determine the efficacy of plain radiographs in the detection of pelvic fractures and dislocations in patients with acute pelvic trauma by using CT as the gold standard. CT scans and plain films collected prospectively in 50 patients with acute pelvic injuries were evaluated independently, and fractures and dislocations were identified and tabulated. Of a total of 162 fractures and dislocations seen on CT, only 14 (9%) were misdiagnosed on plain films. None of these misdiagnoses altered patients' management. Sixteen (80%) of 20 cases of intraarticular fragments in the hip joint associated with acetabular fractures were not identified on plain films. We conclude that plain film examination of the patient with pelvic trauma is sufficient to identify virtually all clinically important fractures and dislocations. Plain radiographs alone are not accurate in detecting fracture fragments within the hip joint.     

鼻骨骨折影像诊断的比较研究

目的 通过3种影像学方法的比较，选择合理的鼻部外伤影像学检查方法。方法 回顾分析53例鼻骨骨折患者的X线鼻骨侧位像，冠状和横断CT扫描影像资料。以冠状位＋横断位CT扫描的结果为准，比较了各种检查方法之间对鼻部外伤影像学征象的检出率。结果 冠状位＋横断位CT扫描合用的诊断效果最好。X线鼻骨侧位片仅能检出64.15%的鼻骨骨折，对上颌骨额突骨折等其他鼻部外伤均不能诊断。在鼻骨或上颌骨额突骨折的诊断中，冠状位CT扫描显著优于横断位CT扫描，而在鼻泪管骨折，鼻颌缝分离，鼻骨间缝增宽的诊断上则横断位CT扫描显著优于冠状位CT扫描。结论 在鼻部外伤的影像学检查中仅利用鼻骨X线侧位片是不够的;为了解有无鼻骨或上颌骨额突骨折应首先作鼻部冠状位CT扫描，如经济条件许可，可加作鼻部横断位扫描。     

CT detection of cortical fracture of the femoral head associated with posterior hip dislocation

Posterior dislocation of the femoral head is a common injury in automobile accidents and is frequently associated with fractures of the posterior acetabular rim. Fractures of the anterior cortex of the femoral head have not been described. One hundred sixty-four cases of posterior hip dislocation presenting consecutively to our shock trauma unit and emergency department during a 3-year period were evaluated with plain film radiology and CT. In 21 cases (13%), CT showed an anterior cortical fracture of the femoral head that could not be seen on plain radiographs. This injury is similar to the Hill-Sachs lesion of the humerus that results from anterior dislocation. The anterior cortical fracture was associated with fractures of the posterior acetabulum in 18 cases (86%). The anterior fracture is caused by impaction of the anterior femoral head against the posterior acetabular rim at the time of dislocation. We conclude that anterior cortical fracture of the femoral head is a common accompaniment to posterior acetabular dislocation.     

严重髋臼骨折

严重髋臼骨折是一种复杂损伤。可分为前、后柱、横、Y／T形和臼顶骨折五类。大多数髋臼骨折均有错位和股骨头中心脱位。牵引不能复位者应行手术治疗。本文报告17例严重髓臼骨折，其中9例行手术治疗效果满意。     

CT of acetabular fractures: analysis of fracture patterns

Thirty-one consecutive patients who sustained acetabular fracture or posterior femoral head dislocations were examined by computed tomography (CT). By analysis of closely spaced, thin CT images, it was possible to characterize the three-dimensional nature of these injuries. Traditional classification into anterior column, posterior column, and complex two-column fractures was facilitated. CT was especially useful in evaluation of the two-column fractures in which unique information concerning the configuration of the fracture, integrity of the acetabular dome and quadrilateral surface, and identification of the stable fragment was obtained. Surprisingly constant fracture patterns were identified. CT was also useful in determination of presence or absence of loose bodies in the joint and in evaluation of the femoral head and sacroiliac joint in all types of fracture.