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ORIGINAL ARTICLE

Evaluation of Computed Tomography forDetermining the Diagnosis of Acetabular Fractures

Robert V. OToole, MD, Garrick Cox, MD, K. Shanmuganathan, MD, Renan C. Castillo, MS,

Clifford H. Turen, MD, Marcus F. Sciadini, MD, and Jason W. Nascone, MD

Objective: We assessed whether, in contrast to reports in theliterature, computed tomographic (CT) scans improve the ability to

classify acetabular fractures in comparison with plain radiographs.

Design: Prospective.

Setting: Level I trauma center.

Patients: Seventy-five patients with 75 acetabular fractures treatedbetween June 2005 and May 2006.

Intervention: Four different image sets for each patient wereevaluated: image set A, Judet view plain radiographs plus axial view

CT scans; image set B, Judet view plain radiographs alone; image set

C, three-dimensional CT reconstructions; and image set D, CT-

simulated anteroposterior and Judet views of the pelvis. The 300

image sets were viewed in random order by four orthopaedic trauma

fellowship-trained surgeons who independently recorded a diagnosis.

A gold standard diagnosis was determined by group consensus.

Main Outcome Measurements: Agreement among four imagingmethods was evaluated by using kappa statistics for multiple raters

and nominal data.

Results: Comparing the gold standard diagnosis with the four imagesets, Judet view plain radiographs had a worse kappa value than

CT scans (P, 0.05). The adjusted kappa values for all three image

sets that included CT scans averaged greater than 0.62, showing

substantial agreement, whereas the image set with plain radiographs

alone (image set B) had a lower kappa value of only 0.48 (P, 0.05).

Conclusions: In contrast to previous reports in the literature, theaccuracy of plain radiographs alone was less than the accuracy of CT

scans in terms of diagnosis. The interobserver reliability was also

worse for plain radiographs alone.

Key Words: acetabular fractures, computed tomography, plain

radiographs, diagnosis, three dimensional reconstructions, simulated

Judet views

(J Orthop Trauma 2010;24:284290)

INTRODUCTIONAdequate radiographic assessment is essential for the

diagnosis and treatment of acetabular fractures. Three plainradiographic views traditionally have been used to define thefracture pattern: anteroposterior view, obturatoroblique Judetview, and iliacoblique Judet view of the pelvis.13 Oncecomputed tomography came into common use, axial viewcomputed tomographic (CT) scans were added to the Judetviews for preoperative evaluation.4

Preoperative radiographic evaluation with the Letourneland Judet classification system typically is used to classifyacetabular fractures18 and to plan for operative approaches.The Letournel and Judet system includes 10 fracture types that

are divided into five elementary fracture patterns and fiveassociated fracture patterns.3 One previous study analyzed theinterobserver reliability of the Letournel and Judet fractureclassification system and found substantial interobserverand intraobserver agreement with kappa values on the orderof 0.7.5

Recent advances in CT include the capability to producethree-dimensional CT reconstructions and simulated ante-roposterior and Judet view radiographs derived from CTscans.912 Despite the emerging use of the new three-dimensional CT imaging modalities to help classify and planfor treatment of acetabular fractures, the influence of theimaging modalities on diagnosis has not yet been wellcharacterized. The few studies examining the issue have

questioned the usefulness of CT scans for evaluatingacetabular fractures.5,13 Our hypothesis was that the use ofCT scans improves accuracy in classifying acetabular fracturesin comparison with plain radiographs alone.

PATIENTS AND METHODS

Inclusion CriteriaAfter obtaining Institutional Review Board approval, we

retrospectively reviewed a database that had been prospec-tively collected and designed for this study. Between June

Accepted for publication October 28, 2009.From the R Adams Cowley Shock Trauma Center, Department of Orthopaedics,

University of Maryland School of Medicine, Baltimore, MD.The authors report no financial disclosures related to the content of this

manuscript.Reprints: Robert V. OToole, MD, 22 S. Greene Street, T3R62, R Adams

Cowley Shock Trauma Center, Department of Orthopaedics, University ofMaryland School of Medicine, Baltimore, MD 21201 (e-mail: [email protected]).

Copyright 2010 by Lippincott Williams & Wilkins

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2005 and May 2006, 178 consecutive patients presented at ourLevel I trauma center with acetabular fractures. Patients wereexcluded from the study for the following reasons: if any of thetypes of images we were studying were not available forviewing; if the imaging studies had not been completed; andif any identifiable markers such as associated fractures or

hardware from previous treatment were seen on the images.Most of the exclusions were because three-dimensional CTreconstructions were not available for analysis. However, no

patient was excluded because of poor image quality becausewe wanted to study the imaging modalities as they were usedin clinical practice as opposed to including only idealimages that might be very difficult to routinely obtain. Afterexclusions, the study group included 75 patients with 75fractures.

Image SetsFour different image sets were evaluated for each

patient: image set A, Judet view plain radiographs plus axial

view CT scans; image set B, Judet view plain radiographsalone; image set C, three-dimensional CT reconstructions(Fig. 1); and image set D, CT-simulated anteroposterior andJudet views of the pelvis (Fig. 2). This created 300 total imagesets for viewing. The 300 individual image sets were eachassigned a random number using a computerized randomnumber generator (Microsoft Office Excel 2003 Version 11.8;Microsoft Corporation, Redmond, WA) and had all patientidentifiers removed. The image sets were then randomlyarranged by sorting the random numbers into ascendingnumerical order for viewing. The CT scans were obtained byusing a Phillips Vitrea 2.0 CT scanner (Andover, MA) with3-mm thick soft copy section thickness. The scanning protocolwas use of a 16-section multidetector CT scanner (Brilliance

16 Power CT scanner; Philips Medical Systems, Cleveland,OH) with a detector width of 0.75 mm, pitch of 0.938, androtation time of 0.5 seconds.

The three-dimensional CT reconstructions and CT-simulated anteroposterior and Judet views of the pelvis werecreated by radiologists who used a standardized computerworkstation and software (TeraRecon, San Mateo, CA). Thereconstructions (image set C) and simulated views (image setD) allowed for multiple viewing directions as controlled by theviewer, as is typical clinically. To obtain the three-dimensionalimages, 2 3 2 mm thick images were used. All images wereviewed with a General Electric Picture Archiving and Com-munication System (General Electric Corporation, Waukesha,WI) on an Agfa-Gevaert computerized workstation (Agfa-

Gevaert Group, Mortsel, Belgium).

Image EvaluationEach image set was evaluated in random order (as

described previously) by four trauma fellowship-trainedorthopaedic surgeons who routinely treat acetabular fracturesin separate sessions. The diagnosis was recorded by eachsurgeon as either no fracture evident or as one of the 10types of acetabular fractures of the Letournel and Judetclassification system3: anterior wall, anterior column, posteriorwall, posterior column, transverse, T-type, anterior column or

wall with posterior hemitransverse, both-column, posteriorcolumn and posterior wall, or transverse and posterior wall.

Five weeks after all images had been reviewed by allsurgeons, the gold standard diagnosis was determined by allfour surgeons through a group consensus meeting. For thegold standard diagnosis, all 75 fractures were evaluated withall four imaging methods available; the viewers were still

FIGURE 1. Three-dimensional computed tomography recon-structions of an acetabular fracture. Two views are shown

(AB). The contralateral hemipelvis and femoral head havebeen removed for better visualization. The images can berotated 360 in both the vertical and horizontal planes.

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blinded to the patient identifiers and to the diagnoses made bythe individual surgeons. For any diagnosis with disagreementafter discussion, a vote was taken to determine the goldstandard diagnosis. Disagreement existed regarding only twoof the 75 fractures.

AnalysisWe first compared the four imaging methods regarding

ability to agree with the gold standard diagnosis. Consideringthat the frequencies of the 10 types of acetabular fractures arenot equal in clinical practice nor were they in our data set, theanalysis had to be weighted so that common fracture patternsdid not falsely elevate the level of agreement. Agreement wasassessed with the use of kappa statistics for multiple raters andnominal data.

We next compared the four imaging methods regardingability to consistently predict the diagnosis among surgeons.Again, agreement was assessed with the use of kappa statisticsfor multiple raters and nominal data. Additionally, a sensitivityanalysis was conducted to ascertain that no single rater was

driving the results of the study. Repetition of the analyses afterexclusion of a single rater did not substantially change theoverall study conclusions.

Based on clinical experience of what fracture diagnosesare often debated by residents, fellows, and attendings, wehypothesized that three of the fracture types would be par-ticularly likely to cause disagreement: associated both-column,T-type, and anterior column or wall with posterior hemitrans-verse. Therefore, we repeated these analyses after compressingthe 10 fracture types down to eight. That is, we considered thethree aforementioned fracture types as identical for purposesof this subanalysis to learn whether removing disagreementregarding the three fracture types would change our results.

Statistical AnalysisAgreement between the imaging methods and the gold

standard diagnosis was evaluated with the use of kappastatistics for multiple raters and nominal data. The kappavalues were interpreted by using the method described byLandis and Koch.14 The guidelines propose that kappa valuesof 0 to 0.20 indicate poor agreement, 0.21 to 0.40 fairagreement, 0.41 to 0.60 moderate agreement, 0.61 to 0.80substantial agreement, and greater than 0.80 almost

perfect agreement. Ninety-five percent confidence intervalswere generated by using bootstrap techniques in a commer-cially available statistical package (STATA; SAS Institute,Inc., Cary, NC) yielding comparable results.

RESULTSFor each of the imaging methods (image sets A, B, C,

and D), we assessed agreement with the gold standarddiagnosis. Statistically significant variation in agreement withthe gold standard was shown based on imaging method (P,0.01, analysis of variance). Image set B (Judet view plainradiographs alone) performed more poorly than did the otherthree image sets (P, 0.05, Duncans multiple range test) withonly a 52% rate of agreement with the gold standard diagnosis(Table 1).

FIGURE 2. Simulated anteroposterior (A) and Judet views (BC)created from computed tomography (CT) scans of an acetabularfracture. The images simulate radiographs but are based on CTdata. The images can be rotated 360 about vertical andhorizontal axes. The images are not affected by body habitus,bowel gas, or the presence of contrast agent in the bladder. Thisis the same patient whose images are shown in Figure 3.

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OToole et al J Orthop Trauma Volume 24, Number 5, May 2010


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The results reported in the previous paragraph are notsatisfactory because they do not adjust for chance agreement.That is, raters are likely to agree regarding certain diagnoses(such as posterior wall fractures) that are highly prevalent,even if all the raters do is guess posterior wall for all the

fractures. As discussed, we then adjusted for this effect andcalculated kappa values, which account for the fact that agree-ment exists between raters based on chance alone (Table 2).

When we used the more methodologically rigoroustechnique, image set B (Judet view plain radiographs alone)was again shown to be statistically significantly less accuratethan image sets A, C, and D (P, 0.05, analysis of variance,Duncans multiple range test) in terms of agreeing with thegold standard diagnosis. The image sets that included CT data(image sets A, C, and D) all had kappa values that indicatedsubstantial agreement, whereas the image set that included

plain radiographs alone (image set B) was rated as havingmoderate agreement.

We next analyzed the number of times the raters agreed

on a diagnosis (interobserver reliability) for each of the fourimaging methods to determine which produced the mostconsistent results (Table 3). Image set B (plain radiographsalone) was statistically significantly less consistent than theimage sets that included CT data (image sets A, C, and D)(P, 0.05, analysis of variance, Duncans multiple range test).

We repeated these analyses after compressing the classi-fication system down to only eight fracture types by consider-ing three of the fracture types to be the same (associated

both-column, anterior column or wall with posterior hemi-transverse, and T-type), as discussed previously. Doing soremoved any differences from the data on these three fracturetypes that we thought might cause particularly high levels of

disagreement; however, the reanalysis yielded results similarto those of the initial analysis that analyzed all 10 fracturetypes (data not shown). We then analyzed the data by fracturetype (Table 4); however, the large number of fracture types

presents too small a sample size for statistical analysis regardingthis issue.

DISCUSSIONThe current standard radiographic assessment of

a patient with an acetabular injury begins with three viewsof the pelvis: anteroposterior, obturatoroblique, and iliacoblique.47 With the addition of newer types of images suchas axial view CT scans11,12,1520 and three-dimensionalCT reconstructions,911 it was thought that not only wouldsurgeons be able to better identify marginal impaction or loose

bodies within the acetabulum but the diagnostic accuracy ofthe acetabular fracture patterns might improve.5,13

Little previous work has investigated the influence ofimaging techniques on the diagnosis of acetabular fractures.One study showed that reliability in classifying acetabularfractures by using the anteroposterior view pelvic radiographalone was not improved with additional oblique (Judet)views21; however, the study participants were junior residentsand community orthopaedic surgeons who presumably did nottreat acetabular fractures, so the applicability of that study foracetabular surgeons is unclear. A study of orthopaedic traumasurgeons of various experience failed to show an advantageof axial view CT scans in improving the reliability of theclassification system.5 That study did not analyze three-dimensional CT-based data and used the surgeons opinionfrom the operating room as a gold standard.

Two previous studies have investigated the role of three-dimensional CT scans in the classification of acetabularfractures.13,22 In a smaller study of 20 fractures, only one of the

five participants was an orthopaedic trauma surgeon and thekappa values were low (kappa = 0.24), representing only fairagreement when using either plain radiographs or three-dimensional CT scans.13 The kappa values were much lowerthan those previously reported in the literature5 and muchlower than those in our study in which all the participants wereorthopaedic trauma surgeons. A second larger study of 101fractures evaluated two radiologists diagnoses and foundresults similar to those of our study with interobserveragreement rated as substantial (kappa = 0.70) with multi-detector CT using three-dimensional reconstructions but onlymoderate (kappa = 0.42) with Judet films alone.22 When

TABLE 1. Number of Raters Agreeing With Gold StandardDiagnosis by Imaging Method

Imaging Method

A B C D

4 of 4 30 19 35 33

3 of 4 17 13 10 122 of 4 17 16 10 13

1 of 4 7 9 6 9

0 of 4 4 18 14 8

Percentage agreement 71% 52%* 65% 68%

*Lower agreement with gold standard, P, 0.05.

TABLE 2. Chance-Adjusted Agreement With GoldStandard Diagnosis*

Imaging Method

A B C D

Kappa 0.647 0.480 0.620 0.642

95% confidenceinterval

0.6130.688 0.4370.546 0.5790.656 0.6070.709

*Kappa statistics with 95% confidence intervals.Significant difference at the P, 0.05 level.

TABLE 3. Chance-Adjusted Agreement on Diagnosis AmongImaging Methods*

Imaging Method

A B C D

Kappa 0.560 0.512 0.640 0.659

95% confidenceinterval

0.5190.630 0.4280.581 0.5840.689 0.6170.717

*Kappa statistics with 95% confidence intervals.P, 0.05.




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comparing the diagnoses made during the study with the

diagnoses from the operative reports, agreement was higherwhen based on CT scans than when based on radiographs,although the difference was statistically significant for onlyone of the radiologists (P = 0.01 and 0.06). The applicabilityof the conclusions presented in these studies to diagnosesmade by surgeons who regularly treat acetabular fractures isunknown.

With our study, we retested the hypothesis that CT scansin comparison with plain radiographs alone will improveaccuracy in classifying different acetabular fracture patterns.In contrast to findings previously presented in the literature,5,13

we found that the diagnostic accuracy of plain radiographsalone was worse than that of CT scans, questioning theusefulness of plain radiographs for diagnosis of fracture

pattern. Comparing the gold standard diagnosis with the fourimaging sets, Judet view plain radiographs had a lower

percentage of agreement (52% versus 71%, 65%, and 68%;P, 0.05, analysis of variance, Duncans multiple range test)and a worse kappa value than did the CT scans (P, 0.05,analysis of variance, Duncans multiple range test) (Tables 1and 2). The kappa values for all three imaging methods thatincluded CT scans showed substantial agreement, whereas thekappa values for the plain radiographs alone showed only fairagreement.

Several possible explanations exist to explain why ourfindings differ from those of previous work. In clinical

practice, poor-quality radiographs are somewhat common,

often because of body habitus, inadequate patient rotation,improper x-ray penetration, bowel gas, or contrast agent in thebladder (Fig. 3). We did not exclude any patients from ourstudy because of poor film quality; the included films werethose the surgeon actually used for management of the case.In that manner, we hoped to realistically characterize theinfluence of the imaging studies on surgeons diagnosis. It isunclear whether previous studies included only patientswith adequate plain films, so it is possible that a selection

bias was introduced in the study population of those otherstudies as a result of excluding patients with lower qualityradiographs.

Another possible explanation for the difference between

our findings and the findings of previous reports in theliterature is the detail of the CT reconstructions. Modernsoftware has improved such that recreated images have betterresolution and more options are available for viewing the data.For example, the three-dimensional and simulated views can

be rotated 360 in any direction. Also, the femoral head can besubtracted out of the acetabulum, providing the surgeon withan inside view of the pelvis unlike that of any plain radiograph.

Other possibilities include differences in the details ofour methodology. We used a statistical methodology thatcorrected for chance agreement and unequal fracture patternfrequencies, unlike previous studies. We used a consensusgold standard based on radiographs because we were notconvinced that the operative surgeons opinion of the fracturemorphology should be the gold standard, particularly forfractures with which the approach would not allow access tofracture lines on the opposite column.

Our present study followed patients in a consecutivefashion, recreating clinical practice. This approach caused thenumber of certain types of acetabular fracture patterns to beseen more frequently, such as posterior wall and transverse

posterior wall types (Table 4). Furthermore, a selection biasmight have been introduced toward the radiologists obtainingand saving three-dimensional reconstructions of more in-teresting fracture patterns, because we had to exclude any

patient who did not have three-dimensional reconstructionsavailable for analysis, thus biasing the data set away from

simple fractures and toward fractures that are more prone todisagreement regarding classification. However, we attemptedto account for these factors by adjusting for chance agreementamong imaging methods regarding diagnosis with ourstatistical methods.

Strengths of our study include the randomized, blindedfashion in which four independent trauma fellowship-trainedsurgeons rated each image set for a diagnosis. We looked ata relatively large consecutive series of patients and includedJudet view plain radiographs without regard for image quality,axial view CT scans, three-dimensional CT reconstructions,and CT-simulated anteroposterior and Judet views to best

TABLE 4. Accuracy in Diagnosis as a Function of Fracture Type

Fracture Type(by gold standard)

No. of

Fractures(Total = 75)

Percent

AgreementCT + Judet (A)

Percent Agreement

Actual JudetAlone (B)

Percent

Three-DimensionalCT (C)

Percent AgreementSimulated Judet (D)

Percent Average

Across All FourImaging Modalities

Anterior wall 0

Anterior column 5 75 45 75 65 65

Posterior wall 20 89 79 85 95 87

Posterior column 2 63 63 50 63 60

Transverse 4 81 75 100 81 84

T-type 3 33 0 17 58 27

Anterior column or wall withposterior hemi-transverse

7 43 14 29 39 31

Both-column 11 86 89 95 89 90

Posterior column and posterior wall 4 63 50 75 75 66

Transverse and posterior wall 19 68 36 46 47 49

CT, computed tomography; , not applicable.




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mimic images currently available to acetabular surgeons. Wethink our statistical methods adequately accounted for chance

agreement and variation in the observed frequency of fracturepatterns.Another component of evaluating imaging modalities is

the cost. The professional fee plus the hospital charges for eachof the image sets at our hospital in 2009 are as follows: imageset A, $262; image set B, $687; and image sets C and D, $405.Many institutions obtain A, B, C, and D, which would cost$1354. These cost values represent only one hospitals feeschedule, and further work is required to conduct cost:benefitanalysis of these imaging modalities.

The results of this study suggest future directions forresearch and clinical practice. With improving CT software

and different imaging modality techniques, the preoperativeradiographic workup for patients with acetabular fracturesmight ultimately change. Perhaps after identifying anacetabular fracture on a routine anteroposterior view radio-graph of the pelvis, the only other imaging modality requiredis CT. We have begun to study this protocol at our center.

It has been our experience that it often is not practicalor even possible to obtain additional radiographs of patientswhose images are of poor quality, because the patients might

be hemodynamically unstable or have associated injuries suchas unstable spinal trauma. Furthermore, obtaining Judet viewradiographs of awake patients typically is painful for the

patients. Reshooting additional radiographs in pursuit of theperfect Judet view radiograph subjects patients to additional

pain, radiation, increased costs, and preoperative evaluationtime. CT scans can eliminate all the confounding factors andrecreate a similar image virtually every time. One theoreticaladvantage of actual Judet films is that after rotating the patient45 onto a foam block to elevate one hip to obtain theradiographs, gravity provides stress to the hip that might reveal

subluxation that might not be evident while the patient issupine; however, this phenomenon is unlikely to affect thediagnosis of fracture type and so will require further inves-tigative research.

The CT data obtained during the initial CT scanningcan be used to construct traditional axial view images, three-dimensional reconstructions, and simulated Judet views. Thesimulated Judet views have an appearance similar to that ofa standard radiograph without the imperfections that a plainradiograph might have and can be used in the operating roomor clinic (Fig. 2). The views can be digitally rotated at thesurgeons discretion, recreating the perfect Judet view. Also,the femoral head can be digitally subtracted from three-dimensional views, creating an internal acetabular view that no

plain radiograph has been able to show (Fig. 1).It is important to note that our study investigated only

the usefulness of these imaging modalities in making thediagnosis. Imaging is used to obtain other information such asthe presence of joint impaction, intra-articular fragments, andthe degree of fracture comminution, and to decide on thetreatment and surgical approach, if surgery is indicated. Ourstudy did not assess any of these additional issues. Furtherresearch is required to investigate whether three-dimensionalreconstructions and CT-simulated views are reliable andclinically efficacious and whether they potentially limitradiation exposure, cost, and pain for patients who sustainacetabular fractures.

ACKNOWLEDGMENTSWe acknowledge the important assistance of Mary

Zadnik Newell, OTR/L, Med, and Senior Editor and Writer,Dori Kelly, MA, Department of Orthopaedics, University ofMaryland School of Medicine.

REFERENCES1. Letournel E. Fractures of the acetabulum: a study of a series of 75 cases [in

French]. J Chir (Paris). 1961;82:4787.2. Judet R, Judet J, Letournel E. Fractures of the acetabulum: classification

and surgical approaches for open reduction: preliminary report. J BoneJoint Surg Am. 1964;46:16151646.

FIGURE 3. Example of poor-quality obturatoroblique Judetview (A) and poor-quality iliac-oblique Judet view (B) plainradiographs obtained before operative treatment of anacetabular fracture. Image quality was limited by the patientsbody habitus and bowel gas. This is the same patient whoseimages are shown in Figure 2.




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3. Letournel E. Acetabulum fractures: classification and management. ClinOrthop Relat Res. 1980;151:81106.

4. Letournel E, Judet R. Fractures of the Acetabulum, 2nd ed. New York:Springer; 1993.

5. Beaule PE, Dorey FJ, Matta JM. Letournel classification for acetabularfractures: assessment of interobserver and intraobserver reliability. J Bone

Joint Surg Am. 2003;85:1704 1709.6. Tornetta P III. Displaced acetabular fractures: indications for operative

and nonoperative management. J Am Acad Orthop Surg. 2001;9:1828.7. Mack LA, Harley JD, Winquist RA. CTof acetabular fractures: analysis of

fracture patterns. AJR Am J Roentgenol. 1982;138:407412.8. Mayo KA. Open reduction and internal fixation of fractures of the

acetabulum: results in 163 fractures. Clin Orthop Relat Res. 1994;305:3137.9. Billet FP, Schmitt WG, Gay B. Computed tomography in traumatology

with special regard to the advances of three-dimensional. Arch OrthopTrauma Surg. 1992;111:131137.

10. Burk DL Jr, Mears DC, Kennedy WH. Three-dimensional computedtomography of acetabular fractures. Radiology. 1985;155:183186.

11. Gautsch TL, Johnson EE, Seeger LL. True three dimensionalstereographic display of 3D reconstructed CT scans of the pelvis andacetabulum. Clin Orthop Relat Res. 1994;305:138151.

12. Harley JD, Mack LA, Winquist RA. CT of acetabular fractures: compari-son with conventional radiology.AJR Am J Roentgenol. 1982;138:413417.

13. Visutipol B, Chobtangsin P, Ketmalasiri B, et al. Evaluation of Letournel

and Judet classification of acetabular fracture with plain radiographs and

three-dimensional computerized tomographic scan. J Orthop Surg (HongKong). 2000;8:3337.

14. Landis JR, Koch CG. The measurement of observer agreement forcategorical data. Biometrics. 1977;33:159174.

15. Hayes CW, Balkissoon AR. Current concepts in the imaging of the pelvisand hip. Orthop Clin North Am. 1997;28:617642.

16. Rafii M, Firooznia H, Golimbu C, et al. The impact of CT in the clinicalmanagement of pelvic and acetabular fractures. Clin Orthop Relat Res.1983;178:228235.

17. Brandser E, Marsh JL. Acetabular fractures: easier classification witha systematic approach. AJR Am J Roentgenol. 1998;171:12171228.

18. Hunter JC, Brandser EA, Tran KA. Pelvic and acetabular trauma. RadiolClin North Am. 1997;35:559590.

19. Martin JS, Marsh JL. Current classification of fractures: rational andutility. Radiol Clin North Am. 1997;35:491506.

20. Resnik CS, Stackhouse DJ, Shanmuganathan K, et al. Diagnosis of pelvicfractures in patients with acute pelvic trauma: efficacy of plainradiographs. AJR Am J Roentgenol. 1992;158:109112.

21. Petrisor BA, Bhandari M, Orr RD, et al. Improving reliability in theclassification of fractures of the acetabulum. Arch Orthop Trauma Surg.2003;123:228233.

22. Ohashi K, El-Khoury GY, Abu-Zahra KW, et al. Interobserveragreement for Letournel acetabular fracture with multidetector CT:are standard Judet radiographs necessary? Radiology. 2006;241:

386391.



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Avaliacao TC Acetabulo