False Profile View Research Articles

The False Profile Radiographic View Can Be Used to Accurately Measure Pelvic Incidence

False profile radiographs can be used to measure pelvic incidence. Pelvic incidence (PI) is an important variable associated with spinopelvic balance that has been implicated in a number of hip pathologies, including femoroacetabular impingement, hip osteoarthritis, and slipped capital femoral epiphysis. A lateral radiograph of the pelvis has previously been used to assess pelvic incidence. The false profile radiographic view of the hip has traditionally been used to measure acetabular coverage in the setting of hip dysplasia and femoroacetabular impingement. However, some believe it can also be used to assess spinopelvic balance due to its obliquity. The objective of this study was to examine the accuracy of using a false profile radiograph to obtain an accurate measurement of pelvic incidence. IRB approval was obtained. Radiographs and CT scans of 14 patients from a single institution were retrospectively reviewed. The actual angle of rotation of a false profile view radiograph was calculated using a previously reported method. PI was measured on false profile radiograph by two independent reviewers. PI was also measured on a pelvic CT scan by the same two independent reviewers. Mean PI discrepancy was determined between false profile radiograph and reference CT. Agreement between measurements made on CT scan and false profile radiographs were determined by measuring intraclass correlation coefficient. ICC was also used to determine intra-rater reliability of PI measured on a false profile and CT scan. The mean pelvic incidence was 54.0 degrees (range 38.3-65.9 degrees). Mean rotation of a false profile radiograph was 30.8 degrees from a lateral radiograph (range 21.9-35.5 degrees). There was excellent intra-rater reliability for measurement of PI on false profile (ICC = 0.97, 95% CI 0.85-0.99) and CT (ICC = 0.99, 95% CI = 0.92-1.00). There was excellent agreement between CT and false profile radiographs with regards to PI measurements (ICC = 0.92, 95% CI 0.78-0.98). The mean discrepancy in PI was 2.6 degrees (range 0.4-5.3 degrees). Increased discrepancy in measurement was associated with increased rotation from a lateral radiograph (ICC = 0.93, 95% CI 0.78-0.98). The false profile radiograph can be used to measure pelvic incidence with reasonable accuracy. Increased pelvic rotation results in greater error when measuring pelvic incidence. These results allow for the measurement of an important variable associated with hip pathology on routinely obtained hip radiographs.

Comparison of Radiographs and Computed Tomography for the Screening of Anterior Inferior Iliac Spine Impingement

To compare radiographic and 3-dimensional (3D) computed tomography (CT) imaging modalities for the screening of anterior inferior iliac spine (AIIS) impingement by establishing imaging measurement related to the AIIS. Anteroposterior and false-profile radiographs and 3D CT scans were obtained on 10 human cadaveric pelvises. On the anteroposterior view for each methodology, 2 measurements were calculated: distance to the most lateral AIIS from the 12 o'clock position on the acetabular rim, and the angle between the lateral AIIS and the sagittal plane. On the false-profile view for each methodology, 2 measurements were calculated: distance to the anterior AIIS from the 12 o'clock position on the acetabular rim, and the angle between the anterior AIIS and the sagittal plane. Inter-rater and intrarater reliability analyses were performed for both methods in addition to an intermethod analysis. The radiographic false-profile view was the most repeatable orientation, with intraclass correlation coefficients showing excellent reproducibility in both inter-rater (angle: 0.980, distance: 0.883) and intrarater (angle: 0.995, distance: 0.995) analyses. The mean distance from the 12 o'clock position of the acetabular rim to the most anterior/lateral aspect of the AIIS was 41.4mm and 16.0mm on the radiographic false-profile and anteroposterior views, respectively. Intermethod analysis showed a systematic, quantitative bias between modalities (anteroposterior view:-4.1mm, 6.7°; false-profile view:-0.1mm, 8.3°), which will remain relatively consistent as evidenced by the strong individual reproducibility of each measurement. AIIS morphology in relation to the acetabular rim 12 o'clock position and its angle relative to the sagittal plane can be quantitatively determined using either radiographic or 3D CT imaging modalities. Radiographic evaluation may be a valuable tool in the screening of AIIS impingement.

Preoperative diagnostic imaging and planning

A correctly chosen radiographic technique, good image quality and correct image interpretation are the basis of all surgical planning. It is only when the cause and extent of the hip pathology are evaluated carefully based on radiologic imaging that the long-term surgical success of hip and pelvis osteotomy is possible. This article gives an overview over performance, quality criteria and interpretation of the most important radiographic images of the hip. The anterior-posterior pelvic view is the most important radiograph for planning an osteotomy of the hip. Besides the evaluation of the underlying cause, the caput-collum-diaphyseal angle (CCD) can be calculated from the pelvic view. For the evaluation of the real femoral antetorsion angle (AT-angle) a RippsteinII projection needs to be performed. Lequesne's false-profile view is important to assess the ventral part of the joint, especially to measure the anterior coverage of the femoral head. In neonates and children, the pelvic hip view is important to assess hip dysplasia. The relevant characteristic lines and angles that should evaluated in the pelvic hip view are the Hilgenreiner line, of the Perkin line, the acetabular angle (AC-angle) and Reimers migration index. Computed tomography allows 3D surgical planning and is the most accurate technique for measuring the AT-angle. Magnet resonance imaging is of help for the evaluation of hip pathologies such as labrum and cartilage injuries. MRI for this purpose should always be performed as anMR-arthrography.

Preoperative Radiographic Evaluation of Patients With Pelvic Discontinuity

BackgroundPelvic discontinuity (PD) is a rare but devastating mechanism of failure in total hip arthroplasty. Radiographic findings have been described for the identification of PD. However, no study has specifically examined radiographic parameters and the utility of specific views in the preoperative identification of PD. MethodsWe performed a retrospective review of 133 patients who underwent acetabular revision for PD. Preoperative radiographic studies were reviewed including anteroposterior pelvis (AP; n = 133), true lateral hip (n = 132), Judet (n = 47), false profile (n = 4), and computed tomography scans (n = 14). Radiographs were read by the senior authors to identify the following parameters suggestive of PD: visible fracture line, medial migration of the inferior hemipelvis, and obturator ring asymmetry. ResultsUsing only the AP view, the fracture line was visible in 116 (87%), medial migration of the inferior hemipelvis in 126 (95%), and obturator ring asymmetry in 114 (86%). A fracture line was visualized in 65 of 132 hips (49%) evaluated with laterals, 36 of 47 hips (77%) evaluated with Judet views, 3 of 4 (75%) evaluated with a false profile view, and 10 of 14 (71%) evaluated with computed tomography. ConclusionPreoperative evaluation with a combination of an AP pelvis radiograph, plus a true lateral radiograph of the hip, plus Judet films in combination with the criteria for discontinuity defined in this article, allowed for identification of PD in a 100% of patients.

Radiographic Identification of Arthroscopically Relevant Acetabular Structures

Background: The anatomy of the acetabulum has been described extensively in the literature, but radiographic acetabular guidelines have not been well established. This study provides a radiographic map of acetabular landmarks in the hip. Purpose/Hypothesis: The purpose of this study was to quantify the precise radiographic location of arthroscopic landmarks around the acetabulum. The hypothesis was that their locations were reproducible despite variability in the anatomy and positioning of pelvic specimens. Study Design: Descriptive laboratory study. Methods: Ten fresh-frozen cadaveric specimens were dissected, and radio-opaque hardware was placed for each landmark of interest. Anteroposterior (AP) and false-profile radiographs were obtained, and measurements were taken using a digital picture archiving and communication system. Results: On AP radiographs, the direct and indirect heads of the rectus femoris were a mean 48.2 ± 4.6 mm and 44.7 ± 4.3 mm proximal to the teardrop line, respectively. The mean radiographic distance between their insertions was 5.0 ± 3.4 mm. Moreover, the anterior inferior iliac spine was a mean 11.5 ± 3.8 mm from the acetabular rim. On false-profile radiographs, the mean distance between the direct and indirect heads of the rectus femoris was 31.4 ± 6.2 mm. The mean distance between the superior margin of the anterior labral sulcus (the psoas-u) and the midpoint of the transverse acetabular ligament was 41.0 ± 5.7 mm. Additionally, the direct and indirect heads of the rectus femoris corresponded to the 2:30 and 1:30 locations on the acetabular clockface, respectively. The midpoint of the transverse acetabular ligament was located at 7 o’clock on the clockface. Conclusion: The most important finding of this study, determined by quantitative measurements, was that the described surgical landmarks had reliable locations on radiographs. Distances between landmarks as well as distances between landmarks and reference lines were reproducible in both AP and false-profile views. Clinical Relevance: An understanding of how acetabular structures present on radiographs could lead to more accurate portal and hardware placement intraoperatively during arthroscopic surgery as well as better preoperative and postoperative assessments.

Sex Differences in Patients With CAM Deformities With Femoroacetabular Impingement: 3-Dimensional Computed Tomographic Quantification

To determine if significant differences exist between male and female CAM deformities using quantitative 3-dimensional (3D) volume and location analysis. Retrospective analysis of preoperative computed tomographic (CT) scans for 138 femurs (69 from male patients and 69 from female patients) diagnosed with impingement from November 2009 to November 2011 was completed. Those patients who presented with hip complaints and had a history, physical examination (limited range of motion, positive impingement signs), plain radiographs (anteroposterior pelvis, 90° Dunn view, false profile view), and magnetic resonance images consistent with femoroacetabular impingement (FAI) and in whom a minimum of 6 months of conservative therapy (oral anti-inflammatory agents, physical therapy, and activity modification) had failed were indicated for arthroscopic surgery and had a preoperative CT scan. Scans were segmented, converted to point cloud data, and analyzed with a custom-written computer program. Analysis included mean CAM height and volume, headradius, and femoral version. Differences were analyzed using an unpaired t test with significance set at P < .05. Female patients had greater femoral anteversion compared with male patients (female patients, 15.5° ± 8.3°; male patients, 11.3° ± 9.0°; P= .06). Male femoral head radii were significantly larger than female femoral heads (female patients, 22.0 ± 1.3 mm; male patients, 25.4 ± 1.3 mm; P < .001). Male CAM height was significantly larger than that in female patients (female patients, 0.66 ± 0.61 mm; male patients, 1.51 ± 0.75 mm; P < .001). Male CAM volume was significantly larger as well (male patients, 433 ± 471 mm(3); female patients, 89 ± 124 mm(3); P < .001). These differences persisted after normalizing height (P < .001) and volume (P < .001) to femoral head radius. Average clock face distribution was from the 1:09 o'clock position ± the 2:51 o'clock position to the 3:28 o'clock position ± the 1:59 o'clock position, with an average span from the 3:06 o'clock position ± the 1:29 o'clock position (male patients, the 11:23 o'clock position ± the 0:46 o'clock position to the 3:05 o'clock position ± the 1:20 o'clock position; female patients, the 11:33 o'clock position ± the 0:37 o'clock position to the 2:27 o'clock position ± the 0:45 o'clock position). There were no differences in the posterior (P= .60) or anterior (P= .14) extent of CAM deformities. However, the span on the clock face of the CAM deformities varied when comparing men with women (male patients, the 3:43 o'clock position ± the 1:29 o'clock position; female patients, the 2:54 o'clock position ± the 1:09 o'clock position; P= .02). Our data show that female CAM deformities are shallower and of smaller volume than male lesions. Further studies will allow further characterization of the 3D geometry of the proximal femur and provide more precise guidance for femoral osteochondroplasty for the treatment of CAM deformities. Female CAM deformities may not be detectable using current 2D nonquantitative methods. These findings should raise the clinician's index of suspicion when diagnosing a symptomatic CAM lesion in female patients.

The False-Profile View May Be Used to Identify Cam Morphology

To identify the accuracy of measuring the alpha angle on the false-profile, anteroposterior (AP), and 90° Dunn lateral views of the hip as compared with computed tomography (CT) scan findings. Forty patients were needed to have power greater than 80%. Forty-five consecutive patients undergoing hip arthroscopy were retrospectively reviewed with preoperative radial oblique CT reformatted scans and plain radiographs. Alpha angles were measured on plain radiographs (AP, 90° Dunn lateral, and false profile) and CT reformatted views. Abnormal alpha angles were considered greater than 50.5°. Two orthopaedic surgeons independently measured the images, and the results were compared between imaging modalities. The false-profile view was 60% sensitive and 89.0% specific for diagnosing cam deformities of the hip. All radiographs combined were 86% sensitive and 75% specific for diagnosing cam deformities. The false-profile view most strongly correlated with the 2-o'clock (R = 0.746, P = .001) and 3-o'clock (R = 0.698, P < .0001) positions. An intraclass correlation coefficient of 0.81 was found for measurement of the alpha angle on the false-profile view. This study has proved that the false-profile view effectively characterizes cam deformity, especially anterior deformity at the 3-o'clock position. Measuring the alpha angle on the false-profile view appears to be reproducible. The false-profile view along with standing AP pelvis and 90° Dunn lateral views of the hip comprises a good screening radiographic series for patients presenting with symptoms of femoroacetabular impingement. Level III, diagnostic study.

Hip Arthroscopy: Where We Are, and Where We Are Going.

Hip Arthroscopy: Where We Are, and Where We Are Going.

The Effect of Acetabular Rim Recession on Anterior Acetabular Coverage

Background: The majority of rim recession for femoroacetabular impingement (FAI) is performed anteriorly and has traditionally been assessed by the lateral center-edge (CE) angle, which correlates most closely with lateral coverage. The radiographic false-profile view permits measurement of anterior coverage via the anterior CE angle and more closely correlates with anterior coverage. Purpose: To answer the following questions: (1) How does incremental anterior rim recession change lateral and anterior CE angles? and (2) Can these changes be predicted by a formula? Study Design: Descriptive laboratory study. Methods: Twelve cadaveric hips were dissected free of soft tissue to expose the anterior acetabular rim. Incremental resections of 2.5 mm (range, 0-10 mm) were performed from the 12- to 3-o’clock position using a Dremel rotary tool. Anteroposterior hip and false-profile radiographs were obtained at each interval using a fluoroscopic C-arm. The lateral and anterior CE angles were measured by 3 orthopaedic surgeons. Results: The average preresection lateral CE angle was 35.1°, and the mean decrease in lateral CE angle from 0 to 10 mm was 9.9°; the average preresection anterior CE angle was 38.4° and the mean decrease in anterior CE angle from 0 to 10 mm was 18.2°. The anterior CE angle decreased by a factor of 1.9 when compared with the lateral CE angle (P = 2 × 10−7). The lateral CE angle decreased by approximately 1° (1.0°) per millimeter of rim recessed. The anterior CE angle decreased by approximately 2° (1.8°) per millimeter of rim recessed. Conclusion: The lateral CE angle should not be extrapolated to reflect anterior acetabular coverage. The anterior CE angle is a superior marker and predictably decreases with rim recession at double the rate of the lateral CE angle. Clinical Relevance: The false-profile view is recommended in the perioperative workup for all patients undergoing arthroscopic treatment of pincer impingement.

Labral Injury: Radiographic Predictors at the Time of Hip Arthroscopy

The purpose of this study was to investigate the influence of multiple demographic and radiographic findings on the size of labral tears identified at the time of hip arthroscopy. Data were prospectively collected for patients treated with arthroscopic labral repair or debridement from February 2008 to August 2011. Preoperative radiographic and demographic data were collected for 392 patients during the study period. Exclusion criteria included revision surgery and previous hip conditions. An anteroposterior pelvic view, 45° Dunn view, and false-profile view were used to measure Tönnis grade, neck-shaft angle, alpha angle, lateral center edge angle (LCEA), anterior center edge angle (ACEA), acetabular inclination, and the extent of crossover sign when present. At the time of surgery, labral tear size and location were documented for all patients, using traditional acetabular clock face nomenclature for sizing. A multiple linear regression analysis was then performed to assess the correlation of radiographic and demographic findings with the size of the labral tear. Regression analysis displayed statistical significance for sex (P < .0001), age (P < .0001), and alpha angle (P = .005) with labral tear size. For female patients, Tönnis grade (P = .0004) and neck-shaft angle (P = .004) correlated with labral tear size. This model accounted for only 26% of variation in labral tear size. Preoperative risk factors for the extent of labral tear size are male sex, increasing age, and increasing alpha angle. Labral tears were larger in female patients with higher Tönnis grades and lower neck-shaft angles. Measurements of acetabular coverage and version showed no correlation with labral tear size. The majority of labral tear size variation was not accounted for in this model. Level IV, therapeutic case series.

CT false-profile view of the hip: a reproducible method of measuring anterior acetabular coverage using volume CT data.

To devise a simple, reproducible method of using CT data to measure anterior acetabular coverage that results in values analogous to metrics derived from false-profile radiographs. Volume CT images were used to generate simulated false-profile radiographs and cross-sectional false-profile views by angling a multiplanar reformat 115° through the affected acetabulum relative to a line tangential to the posterior margin of the ischial tuberosities. The anterolateral margin of the acetabulum was localized on the CT false-profile view corresponding with the cranial opening of the acetabular roof. Anterior center edge angle (CEA) was measured between a vertical line passing through the center of the femoral head and a line connecting the center of the femoral head with the anterior edge of the condensed line of the acetabulum (sourcil). Anterior CEA values measured on CT false-profile views of 38 symptomatic hips were compared with values obtained on simulated and projection false-profile radiographs. The CT false-profile view produces a cross-sectional image in the same obliquity as false-profile radiographs. Anterior CEA measured on CT false-profile views were statistically similar to values obtained with false-profile radiographs. CT technologists quickly mastered the technique of generating this view. Inter-rater reliability indicated this method to be highly reproducible. The CT false-profile view is simple to generate and anterior CEA measurements derived from it are similar to those obtained using well-positioned false-profile radiographs. Utilization of CT to assess hip geometry enables precise control of pelvic inclination, eliminates projectional errors, and minimizes limitations of image quality inherent to radiography.

Cup Version Can be Accurately Measured on the False Profile View Radiograph

Accurate measurement of cup version on plain radiographs remains difficult due to the two-dimensional projection of an ellipse and difficulty obtaining reproducible radiographs. Determine: 1) if the cup angle measured on the false profile view (FPV) could be used to determine radiographic cup version; 2) how patient positioning would affect cup angle measurement on the FPV; 3) if implant cup design affects cup angle measurement. Three cup version positions were assessed in a sawbone: 13° (normal); 28° (excessive anteversion) and -2° (retroversion). Cup angle was measured on the FPV at five different degrees of pelvic rotation within each cup version group. Pelvic rotation was quantified using the ratio of the inter-femoral head distance measured on the FPV versus the anteroposterior radiographs (FP/AP ratio). Eighty patients (40 metal-on-polyethylene, 40 metal-on-metal) post-total hip were also assessed. Cup version was assessed with Einzel-Bild-Roentgen-Analysis software (EBRA). R2 was calculated to assess correlation between both measurement methods. For the sawbone model, an R2 of 0.95 was obtained. For patients, overall R2 was 0.56 with an FP/AP ratio of 0.3-0.49 having an R2 of 0.72. The EBRA anteversion versus cup angle scatterplot had an R2 of 0.72 (95%CI: +/-7.8°). Subgroup analysis revealed no differences between the metal-on-poly and metal-on-metal for cup angle measurements. The intra-class coefficient for intra- and inter-observer reliability for all cases (individual and combined FP/AP groups) was 0.98 to 0.99. The FPV cup angle measurement value provides an accurate measurement of radiographic cup anteversion with well-defined patient position parameters.

Can False Profile View Radiographs of the Hip accurately identify CAM lesions? A retrospective radiographic analysis with computed tomography comparison

Dunn, Frog Leg Lateral, and AP radiographic views have been verified to accurately correlate with three-dimensional imaging while assessing for CAM lesions of the hip. The false profile radiographic view of the hip has traditionally been used to measure acetabular coverage in the setting of femoroacetabular impingement but some believe it can also be useful in assessing the morphology of the femoral head-neck junction. The objective of this study was to examine the accuracy of using a false profile radiograph of the hip to identify CAM lesions as compared to three-dimensional CT scan findings. An a prior power analysis using the results from a previous study showed we needed 45 patients to have (1-β>0.80. Patients undergoing hip arthroscopy between January 2011 and September 2012 were reviewed. Patients were included if they had a CT scan performed at our institution and if they had adequate screening radiographs in our PACs system(AP pelvis, 90-degree Dunn lateral and false profile). Alpha-angle measurements were performed on radial oblique CT scans and plain radiographs as previously described by Notzli. 2 physicians measured each x-ray and then re-measured 3 months later. An alpha angle > 50° was used as a cut-off for abnormal. SPSS was used to perform all statistics. 45 patients were reviewed, 24 females and 21 males, 32 right hips and 13 left hips. The average age was 35 yo (17-53 yo). 32 hips had a cam lesion on reformatted CT (α-angle > 50°). 31 hips had a cam lesion present about the 2 o'clock position of the femoral head-neck junction and 19 hips had a cam lesion present about the 3 o'clock position. The false profile view was found to be 60% sensitive and 89% specific at identifying cam lesions. When combined with the AP pelvis and 90-degree Dunn lateral views, this series was found to be 86% sensitive and 90% specific. The false profile view had a strong correlation to both the 2 o'clock and 3 o'clock views (r = 0.75 and 0.70 respectively). The False Profile view has a 76% agreement with the 2 o'clock view and an 83% agreement with the 3 o'clock view. Inter and Intra-Observer Correlation Coefficients were 0.81 & 0.88 respectively. This is the first study to suggest that the false profile view can be effectively used to assess the femoral head-neck junction. This has important implications for diagnostic and treatment purposes, as the false profile view has traditionally only been used to only assess for anterior acetabular coverage (pincer-type impingement). We have found that the false profile view effectively characterizes CAM lesions about the anterior portion of the femoral head-neck junction from 2 o'clock to 3 o'clock. Measuring the alpha angle on this view appears to be a reproducible with a significant ICC. In combination with the AP and 90-degree Dunn lateral views the false profile view allows for a physician to fully assess for CAM-lesions about the anterosuperior head neck junction.

Reliability of a new hip lateral view to quantify alpha angle in femoroacetabular impingement

BackgroundRadiographic measurement of the alpha angle (AA) in femoroacetabular impingement (FAI) is not well codified and invasive techniques such as MR- or CT-arthrography remain the gold standard. Excessive acetabular coverage described in pincer-type FAI can be seen on plain radiographs but has never been quantified and anterior center edge (ACE) angle, described on the false-profile view (FP) to measure anterior acetabular coverage has never been evaluated in FAI. HypothesisIn this study we wanted to determine if a plain radiograph could efficiently measure AA compared to CT-arthrography and if ACE could quantify the acetabular coverage in FAI. Materials and methodsWe developed a hip view combining a lateral view and a FP, called profile view in impingement position (PIP). Twenty-six patients operated for FAI had CT-arthrography, PIP and FP. Nineteen control subjects had the PIP. AA were measured twice by three raters and ACE once. We compared AA measured on patients between CT and PIP, on PIP between patients and controls, ACE measured on patients between PIP and FP, and did a reproducibility analysis. Means were compared by paired or unpaired t-tests; reproducibility was measured by intraclass correlation coefficient (ICC). ResultsMean AA was 65.8° (range, 48–85°) on CT-arthrography and 63.9° (range, 50–87°) on PIP (P>0.05). ICC for PIP measures were 0.8–0.9 for intra-rater and 0.6–0.9 for inter-rater reliability. Mean AA on PIP in patients was 63.3° (range, 52–87°) and 44.9° (range, 34–67°) in controls (P<0.001). Mean ACE was 26.8° (range, 14–41°) on PIP and 32.8° (range, 18–56°) on the FP (P=0.015). DiscussionThe PIP is a reliable view to measure the AA in FAI as measures on PIP and CT-arthrography were not significantly different with a good reproducibility. All of the painful hips and 2 controls had an AA>50°. PIP was not efficient to measure ACE. Level of evidenceLevel III, case-control study.

Evaluation of a method for the assessment of anterior acetabular coverage and hip joint space width

The false-profile view (FP) is an oblique view of the acetabulum and a true lateral view of femur and joint. It evaluates anterior and posterior hip joint space width (JSW) and anterior acetabular coverage using the vertical-center margin angle (VCA). The biplanar slot scanner (SS) allows simultaneous bilateral acquisitions of oblique views of hip joints. The aim of this work was to compare SS versus FP for the evaluation of VCA and JSW and to test its reproducibility and validity. A prospective study of 28 patients (55 hips) with hip pain was performed from November 2011 until May 2012. Two readers measured VCA and JSW. JSW was normalized by the diameter of the femoral head for each technique. The radiation exposure was recorded and compared between the two modalities. Student's t test and the Pearson's correlation assessed the agreement between SS and FP. The intraclass correlation coefficient (ICC) was used to assess the interobserver agreement. The mean VCA angle was 32.1° (± 7.1°) and 30.3° (± 8.5°) with FP and SS, respectively. The coefficient of correlation was 0.90 (p < 0.01). The coefficient of correlation of normalized JSW was 0.83, 0.85, and 0.87 at anterior, vertical, and posterior points, respectively). The ICC was between 0.69 and 0.81 for each modality. The mean radiation exposure was 1.33 (± 0.02) mGy versus 8.69 (±0.04) mGy for FP and SS, respectively (p < 0.0001). SS has the potential advantages of simultaneous bilateral acquisition, higher standardization, and is less irradiating. SS is reliable for coxometry.

Identifying Cam Lesions on the False Profile View

Objectives:Recently the AP, Dunn and Frog Leg Lateral radiographic views have been verified to accurately reflect the findings of three dimensional imaging while assessing for cam lesions. The false profile radiographic view is traditionally used to measure acetabular coverage in the setting of femoroacetabular impingement. We believe it should also be used to assess the femoral head neck junction. Our objective is to verify the accuracy of this view with respect to 3D CT scan findings.Methods:We retrospectively reviewed 37 consecutive surgical patients between May 2012 and September 2012 with preoperative radial oblique reformatted CT scans and plain radiographs. Alpha angles were measured on plain radiographs (AP, Dunn, False Profile) and CT reformats. Abnormal alpha angles were considered greater than 55 degrees and the CT scans were considered gold standard. Post-operative radiographs were also measured. Two physicians independently measured the images and the results were compared.Results:The false profile view was 70.6% sensitive and 95.0% specific for diagnosing a cam lesion. It was noted that the false profile view was 1.31 times better than other views at visualizing the anterior head-neck junction at a 3 o’clock position (See image 1). The false profile view pre-operative mean alpha angle was 53.4° versus its post-operative mean alpha angle was 41.9°, Δ = 11.5° (t = 0.001). The interclass correlation coefficient (ICC) was found to be 0.81.Conclusion:This is the first study to suggest using the false profile view to assess the femoral head neck junction. For diagnostic and treatment purposes, the false profile view effectively characterizes cam lesions, particularly anterior 3 o’clock lesions. Further, it shows promising results as a peri-operative assessment tool to verify adequate osteoplasty. Measuring the alpha angle on this view also appears to be a reproducible with a significant ICC. We believe this view should be used for both acetabular coverage measurements as well as for femoral head neck junction measurements.

Effectiveness of False Profile Radiographs in Detection of Pelvic Discontinuity

Pelvic dissociation is a rare but serious potential complication of total hip arthroplasty. The purpose of this study is to evaluate the effectiveness of the false profile view compared with traditional radiographs in detecting pelvic dissociation. Ten cadaver pelves were skeletonized, and noncemented acetabular hip arthroplasty components were implanted. Anteroposterior, lateral, iliac oblique, and false profile radiographs were obtained before and after creating pelvic dissociations and analyzed in a blinded fashion. The sensitivity of the false profile view for detecting pelvic dissociation was 79% (confidence interval, 70-86), which was greater than the sensitivity for anteroposterior and lateral views. This difference was statistically significant. False profile views are a potentially valuable addition to the traditional radiographic evaluation of pelvic discontinuity in hip arthroplasty.

Hip Morphologic Measurements in an Egyptian Population

The study of acetabular morphology has shown that there are geographic differences in the morphology and prevalence of acetabular dysplasia among different ethnic groups. However, few data exist on the shape of the acetabulum in various populations around the world. In this study, we examined samples of pelvic radiographs from Egyptian adults. Acetabular dysplasia in adults is characterized by a shallow and relatively vertical acetabulum.The aim of this study was to examine acetabular morphology to determine the prevalence of hip dysplasia in adult Egyptians. This included 244 adults, 134 men and 110 women between 18 and 60 years, who were used to measure center edge angle, acetabular Sharp angle, acetabular head index on anteroposterior radiographic views of the hip joints, and vertical center anterior margin angle on false profile views. The radiographs were taken of patients with no hip complaints at Tanta University Hospital.The results were statistically studied according to the age, height, and weight of patients. The prevalence of acetabular dysplasia was 2.25% for Egyptian men and 3.6% for women with respect to center edge angles, vertical center anterior margin angle, and acetabular head index.We concluded that gender variations in the morphology of the acetabulum and sex influences geometrical measurements of the acetabulum. Egyptian women were more dysplastic than men using the 4 parameters of hip measurements. There are also racial variations in hip morphology.

Arthroscopic Analysis of the Radiologic Abnormalities of the Hip Associated with Anterior Femoroacetabular Impingement

� Purpose: We wanted to arthroscopically analyze the femoral osseous abnormalities (bumps) in hips with anterior femoroacetabular impingement (FAI) and the other radiologic abnormalities of the hip joint associated with this. Materials and Methods: We retrospectively reviewed the radiographs of 45 patients (51 hips) who underwent arthroscopic treatment under the impression of FAI from January to August, 2008. The indications for surgery included persistent hip pain, the absence of advanced osteoarthritis, physical examination or MRA findings consistent with an acetabualr labral tear. Preoperative and postoperative plain radiographs (pelvis AP, frog-leg lateral, cross table lateral and the false profile view) were taken. As the occasion demanded, 3D-CT or MRA were performed. Results: For the radiologic findings, a decreased head-neck offset (<8 mm) was seen in 15 hips. Femoral bumps were seen in 26 hips and among them, 11 hips were associated with acetabular retroversion, 5 hips were associated with a prominent acetabular rim and 13 hips were located on the flattening of the neck due to a decreased offset. Pistol grip deformity was found in 21 hips and acetabular retroversion was done in 32 hips. Regarding the secondary changes, spurs on the acetabulum of the femur were found in 14 hips and femoral bony cysts were found in 23 hips. Arthroscopically, all the hips had acetabular degenerative labral tear and the acetabular cartilage was injured in 32 hips (62.7%). Among them, 25 hips underwent acetabular retroversion. Conclusion: Femoral osseous abnormalities are seen in various locations and these abnormalities have various shapes. A considerable number were associated with pincer impingement and they could produce a 'kissing lesion' between the acetabulum and femur. Identification of these abnormalities on radiographs aids confirming FAI in hips with symptomatic early osteoarthritis.

Descriptive epidemiology of mechanical hip pathology in adults under 50 years of age. Prospective series of 292 cases: Clinical and radiological aspects and physiopathological review

Two hundred and ninety-two patients, aged between 16 and 50 years and presenting with mechanical hip pathology, were included in a prospective multicenter study. The descriptive study concerned the clinical examination and analysis of three X-ray views (AP pelvic, Lequesne false profile and lateral axial view). The series comprised 62% males, mean age 35 years, with 53% right side and 22% bilateral involvement. Initial trauma was reported in 19% of cases, and direct familial history of hip pathology in 20%. Seventy percent of the patients played sports, 30% were high-level athletes, and 17% played combat sports. The physical impingement sign was present in 18% to 65% of cases depending on the variant studied. On imaging (n=241), 62% of hips showed osteoarthritis, with 25% at the evolved stage. In the series, as a whole, there was a 35% rate of dysplasia, 63% of impingement and 5% of normal X-ray results. The radiologic impingement aspects were 58% cam-type, 19% pincer-type and 23% mixed. Twenty-two percent of dysplasia cases showed signs of associated impingement. Pain experienced exclusively in flexion/internal rotation/adduction on examination showed little sensitivity (20%) but considerable specificity (86%) for the main diagnosis of impingement. The links between impingement and dysplasia are discussed, and an integrative schema of all risk factors is put forward.