Anteroposterior Pelvis Research Articles

The Association of Sacro-Femoro-Pubic Angle and Postoperative Dislocation Following Total Hip Arthroplasty

BackgroundSpino-pelvic orientation may affect dislocation risk following total hip arthroplasty (THA). It can be measured on lateral lumbo-pelvic radiographs. The sacro-femoro-pubic (SFP) angle, measured on an antero-posterior (AP) pelvis radiograph, is a reliable proxy for pelvic tilt, a measurement of spino-pelvic orientation measured on a lateral lumbo-pelvic radiograph. The purpose of this study was to investigate the relationship between SFP angle and dislocation following THA. MethodsAn Institutional Review Board-approved retrospective case-control study was conducted at a single academic center. We matched 71 dislocators (cases) to 71 nondislocators (controls) following THA performed by 1 of 10 surgeons between September 2001 and December 2010. Two authors (readers) independently calculated SFP angle from single preoperative AP pelvis radiographs. Readers were blinded to cases and controls. Conditional logistic regressions were used to identify factors differentiating cases and controls. ResultsThe data did not show a clinically relevant or statistically significant difference in SFP angles after adjusting for gender, American Society of Anesthesiologists classification, prosthetic head size, age at time of THA, measurement laterality, and surgeon. ConclusionWe did not find an association between preoperative SFP angle and dislocation following THA in our cohort. Based on our data, SFP angle as measured on a single AP pelvis radiograph should not be used to assess dislocation risk prior to THA.

A Novel Method to Calculate Functional Pelvic Tilt Using a Standing Anteroposterior Pelvis Radiograph.

Functional patient-specific acetabular component positioning is important in total hip arthroplasty. We preoperatively evaluate the pelvic tilt (PT) on standing anteroposterior (AP) pelvis radiographs using a novel measurement and then recreate this intraoperatively using imaging. The purpose of this study was to determine if there is a linear correlation between this novel measurement and the actual PT. A retrospective study of 200 patients was performed, measuring PT on standing lateral radiographs as the angle between the anterior superior iliac spines and the pubic symphysis. On the AP pelvis radiographs, the trans-teardrop (TT) line was drawn between the teardrops. The vertical distance between the TT line and the top of the pubic symphysis (TTPS) was then measured. A ratio was made between the lengths of both lines to account for the overall size of the pelvis (TTPS/TT). Linear regression analysis was then performed between PT and TTPS/TT. There was a strong linear correlation between the TTPS/TT ratio on AP pelvis radiographs and PT on lateral radiographs (r= 0.785, r2= 0.616, P < .001). On subanalysis of the female cohort, the correlation became even stronger (r= 0.864, r2= 0.747, P < .001). Using regression analysis, a linear equation was created (PT= 97.32 [TTPS/TT] - 5.51), to calculate the PT using the TTPS/TT ratio. There is a strong linear correlation between the TTPS/TT ratio and PT. Using this information, a surgeon can reliably use the distance between the TT line and the superior pubic symphysis on an AP radiograph to recreate the patient's functional PT intraoperatively, allowing for a more accurate patient-specific placement of the acetabular component.

A Deep Learning Tool for Automated Landmark Annotation on Hip and Pelvis Radiographs

BackgroundAutomatic methods for labeling and segmenting pelvis structures can improve the efficiency of clinical and research workflows and reduce the variability introduced with manual labeling. The purpose of this study was to develop a single deep learning model to annotate certain anatomical structures and landmarks on antero-posterior (AP) pelvis radiographs. MethodsA total of 1,100 AP pelvis radiographs were manually annotated by 3 reviewers. These images included a mix of preoperative and postoperative images as well as a mix of AP pelvis and hip images. A convolutional neural network was trained to segment 22 different structures (7 points, 6 lines, and 9 shapes). Dice score, which measures overlap between model output and ground truth, was calculated for the shapes and lines structures. Euclidean distance error was calculated for point structures. ResultsDice score averaged across all images in the test set was 0.88 and 0.80 for the shape and line structures, respectively. For the 7-point structures, average distance between real and automated annotations ranged from 1.9 mm to 5.6 mm, with all averages falling below 3.1 mm except for the structure labeling the center of the sacrococcygeal junction, where performance was low for both human and machine-produced labels. Blinded qualitative evaluation of human and machine produced segmentations did not reveal any drastic decrease in performance of the automatic method. ConclusionWe present a deep learning model for automated annotation of pelvis radiographs that flexibly handles a variety of views, contrasts, and operative statuses for 22 structures and landmarks.

The Transverse Mechanical Axis of the Pelvis for Post-Operative Evaluation of Total Hip Arthroplasty.

Currently, orthopedic surgeons mainly use the inter-teardrop line (IT-line) as the transverse mechanical axis of the pelvis (TAP) for postoperative evaluation of total hip arthroplasty (THA). However, the teardrop is often unclear in the pelvis anteroposterior (AP) radiographs, which makes postoperative evaluation of THA difficult. In this study, we attempted to identify other clear and accurate axes for postoperative evaluation of THA. We calculated the mean and standard deviation of these angles and tested the significance of these angles using t-tests. The inter-teardrops line (IT line) and the upper rim of the obturator foramen (UOF) had smaller angles with the IFH line. The bi-ischial line (BI line) was relatively inaccurate in measurements. We recommend using the IT line as the TAP when the lower boundary of the teardrops is clear and the shapes of the teardrops on both sides of the pelvis are symmetrical. When there is no deformation of the obturator foramen on pelvic AP radiographs, the UOF is also a good choice for the TAP. We do not recommend the BI line as the TAP.

Hip Joint Venting Decreases the Traction Force Required to Access the Central Compartment During Hip Arthroscopy

To investigate the effect of hip joint venting on the magnitude of traction force required to arthroscopically access the central compartment of the hip. Patients who underwent hip arthroscopy for femoroacetabular impingement syndrome prospectively underwent an intraoperative traction protocol. Joint space was measured on fluoroscopic images obtained at 50 and 100 lbs of axial traction in the prevented and vented state, and joint space values were normalized to millimetric values using preoperative anteroposterior pelvis radiographs. Venting was performed by inserting a large gauge spinal needle into the hip joint through the hip capsule and removing the stylet. Joint space differences were compared with paired t-tests, Wilcoxon signed-rank tests, and McNemar tests. Fifty hips in 46 patients were included. Mean joint space before venting was 7.4 ± 2.6 mm and 13.3 ± 2.8 mm at 50 and 100 lbs of traction, respectively. Mean joint space after venting was 13.9 ± 2.3 mm and 15.5 ± 2.4 mm at 50 and 100 lbs of traction, respectively. Mean differences in joint space at 50 and 100 lbs were 6.5 mm (P < .001) and 2.2 mm (P < .001), respectively. Mean joint space at 50 lbs in the vented state was significantly greater than in the pre-vented state at 100 lbs (13.9 mm vs. 13.3 mm; P= .002). The increase in joint space between 50 and 100 lbs of traction was significantly greater in the prevented state than in the vented state (5.9 mm vs 1.6 mm; P= .021). Venting the hip reduces the traction force necessary to arthroscopically visualize and instrument the central compartment of the hip by at least 50%. Further, residual negative pressurization of the hip joint remains after breaking the labral suction seal and venting effectively eliminates this phenomenon to aid in hip joint distraction at lower traction force. Level IV, case series.

Proposed Institutional Diagnostic Reference Levels in Computed and Direct Digital Radiography Examinations in Two Teaching Hospitals

Background: The detectors of both computed radiography (CR) and direct digital radiography (DR) have a wide dynamic range that could tolerate high values of exposure factors without an adverse effect on image quality. Therefore, this study aims to assess patient radiation dose and proposes institutional diagnostic reference levels (DRLs) for two teaching hospitals in Ghana.Materials and Methods: CR and DR systems were utilized in this study from two teaching hospitals. The CR system was manufactured by Philips Medical Systems DMC GmbH, while the DR system was manufactured by General Electric. The entrance skin doses (ESDs) were calculated using the standard equation and the tube output measurements. Free-in-air kerma (μGy) was measured using a calibrated radiation dosimeter. The proposed institutional DRLs were estimated using 75&lt;sup&gt;th&lt;/sup&gt; percentiles values of the estimated ESDs for nine radiographic projections.Results and Discussion: The calculated DRLs were 0.4, 1.6, 3.4, 0.5, 0.4, 1.1, 1.0, 1.2, and 1.7 mGy for chest posteroanterior (PA), lumbar spine anteroposterior (AP), lumbar spine lateral (LAT), cervical spine AP, cervical spine LAT, skull PA, pelvis AP, and abdomen AP, respectively in CR system. In the DR system, the values were 0.3, 1.6, 3.1, 0.4, 0.3, 0.7, 0.6, 0.9, and 1.3 for chest PA, lumbar spine AP, lumbar spine LAT, cervical spine AP, cervical spine LAT, skull PA, pelvis AP, and abdomen AP, respectively.Conclusion: Institutional DRLs in nine radiographic projections have been proposed for two teaching hospitals in Ghana for the first time. The proposed DRLs will serve as baseline data for establishing local DRLs in the hospitals and will be a valuable tool in optimizing patient doses.

Leg-Length Discrepancy Variability on Standard Anteroposterior Pelvis Radiographs: An Analysis Using Deep Learning Measurements

BackgroundLeg-length discrepancy (LLD) is a critical factor in component selection and placement for total hip arthroplasty. However, LLD radiographic measurements are subject to variation based on the femoral/pelvic landmarks chosen. This study leveraged deep learning (DL) to automate LLD measurements on pelvis radiographs and compared LLD based on several anatomically distinct landmarks. MethodsPatients who had baseline anteroposterior pelvis radiographs from the Osteoarthritis Initiative were included. A DL algorithm was created to identify LLD-relevant landmarks (ie, teardrop (TD), obturator foramen, ischial tuberosity, greater and lesser trochanters) and measure LLD accurately using six landmark combinations. The algorithm was then applied to automate LLD measurements in the entire cohort of patients. Interclass correlation coefficients (ICC) were calculated to assess agreement between different LLD methods. ResultsThe DL algorithm measurements were first validated in an independent cohort for all six LLD methods (ICC = 0.73–0.98). Images from 3,689 patients (22,134 LLD measurements) were measured in 133 minutes. When using the TD and lesser trochanter landmarks as the standard LLD method, only measuring LLD using the TD and greater trochanter conferred acceptable agreement (ICC = 0.72). When comparing all six LLD methods for agreement, no combination had an ICC>0.90. Only two (13%) combinations had an ICC>0.75 and eight (53%) combinations had a poor ICC (<0.50). ConclusionWe leveraged DL to automate LLD measurements in a large patient cohort and found considerable variation in LLD based on the pelvic/femoral landmark selection. This emphasizes the need for the standardization of landmarks for both research and surgical planning.

Artificial Intelligence Autonomously Measures Cup Orientation, Corrects for Pelvis Orientation, and Identifies Retroversion From Antero-Posterior Pelvis Radiographs

BackgroundMeasuring cup orientation is time consuming and inaccurate, but orientation influences the risk of impingement and dislocation following total hip arthroplasty (THA). This study designed an artificial intelligence (AI) program to autonomously determine cup orientation, correct for pelvis orientation, and identify cup retroversion from an antero-posterior pelvic radiographs. MethodsThere were 2,945 patients between 2012 and 2019 identified to have 504 computed tomographic (CT) scans of their THA. A 3-dimensional (3D) reconstruction was performed on all CTs, where cup orientation was measured relative to the anterior pelvic plane. Patients were randomly allocated to training (4,000 x-rays), validation (511 x-rays), and testing (690 x-rays) groups. Data augmentation was applied to the training set (n = 4,000,000) to increase model robustness. Statistical analyses were performed only on the test group in their accuracy with CT measurements. ResultsAI predictions averaged 0.22 ± 0.03 seconds to run on a given radiograph. Pearson correlation coefficient was 0.976 and 0.984 for AI measurements with CT, while hand measurements were 0.650 and 0.687 for anteversion and inclination, respectively. The AI measurements more closely represented CT scans when compared to hand measurements (P < .001). Measurements averaged 0.04 ± 2.21°, 0.14 ± 1.66°, −0.31 ± 8.35°, and 6.48° ± 7.43° from CT measurements for AI anteversion, AI inclination, hand anteversion, and hand inclination, respectively. AI predictions identified 17 radiographs as retroverted with 100.0% accuracy (total retroverted, n = 45). ConclusionThe AI algorithms may correct for pelvis orientation when measuring cup orientation on radiographs, outperform hand measurements, and may be implemented in a timely fashion. This is the first method to identify a retroverted cup from a single AP radiograph.

Definition of hip dysplasia in 2023 : Signs of macro and micro instability

Hip dysplasia is acomplex static-dynamic pathology leading to chronic joint instability and osteoarthritis. Because our understanding of the underlying pathomorphologies of hip dysplasia, both on the macro and micro levels, has evolved, an updated definition is needed. What is the definition of hip dysplasia in 2023? By summarizing and reviewing relevant literature, we provide an up-to-date definition of hip dysplasia with aguide to appropriately making the diagnosis. In addition to the pathognomonic parameters, supportive and descriptive indicators, as well as secondary changes are used to fully characterize instability inherent in hip dysplasia. The primary diagnostic tool is always the plain anteroposterior pelvis radiograph, which can be supplemented by additional investigations (MRI of the hip with intraarticular contrast agent; CT) if necessary. The complexity, subtlety, and diversity of the pathomorphology of residual hip dysplasia requires careful, multilevel diagnosis and treatment planning in specialized centers.

INTERTROCHANTERIC FEMUR FRACTURE

Introduction: Intertrochanteric fractures are a type of extracapsular fractures of the proximal femur occurring between the greater and lesser trochanter. They are frequently seen in the elderly because their incidence is higher as life expectancy increases. Objective: to describe the current information related to epidemiology, anatomy, presentation, classification, evaluation and management of intertrochanteric fractures. Methodology: a total of 35 articles were analyzed in this review, including review and original articles, as well as clinical cases, of which 27 bibliographies were used because the other articles were not relevant to this study. The sources of information were PubMed, Google Scholar and Cochrane; the terms used to search for information in Spanish, Portuguese and English were: transtrochanteric, intertrochanteric, femur, fracture, fratura. Results: Intertrochanteric fractures have a bimodal presentation. They have a female to male ratio ranging from 2:1 to 8:1, possibly due to changes in bone metabolism after menopause. They are frequently seen in the elderly because their incidence is higher as life expectancy increases. Plain radiographs are still the initial choice to complement the diagnosis in this type of fractures. It is preferable to take anteroposterior (AP), AP and lateral cross pelvis projections of the affected hip and full body radiographs of the affected femur. Surgical treatment is preferred over conservative treatment except in cases that contraindicate surgery or anesthesia. Conclusions: Intertrochanteric fractures are a type of extracapsular fractures of the proximal femur occurring between the greater and lesser trochanter. Femur fractures have several classifications, recently the classification of intertrochanteric fractures is based on the stability of this area. It is of vital importance to evaluate whether it is an open or closed fracture, in addition to assessing the neurovascular status. The surgical treatment has the mission of providing a stable internal fixation that allows early mobilization and full weight bearing. There are several tools and techniques to provide surgical treatment, however, in our current reality, intramedullary nails are the most used devices in the treatment of intertrochanteric fractures. Regardless of the therapeutic alternative chosen, the mortality risk is 20% to 30% in the first year after the fracture, with males being more affected than females. KEY WORDS: transtrochanteric, intertrochanteric, femur, fracture.

Contemplate iliosacral screw in patients with developmental dysplasia of the hip

ObjectivesOur aim in the study was evaluating sacroiliac morphology in patients with DDH and its possible effect on appropriate iliosacral screw fixation.DesignRetrospective cohort study.SettingLevel of evidence 3.Patients/participantsWe evaluated the anteroposterior pelvis X-ray and pelvic CT scans of patients. We mainly divided the patients into two groups: DDH group (n:105) and control group (n:105).InterventionThe presence of the five qualitative characteristics of sacral dysplasia evaluated according to Route in both groups. The DDH group was divided into four subgroups according to the degree of hip dysplasia.Main outcome measurementThe cross-sectional area, length of the osseous corridor, coronal and vertical angulation evaluated in both groups.ResultsThe DDH group also exhibited a significantly higher S1 coronal and axial angulation, lower S1 cross-sectional area and S1 iliosacral screw length than the control group (p:0.033, p:0,002, p:0.006, p:0,019, respectively). According to the Rout classification, 9% were normal, 31% transient, 58% dysplastic in the DDH group. 45.7% were normal, 38% transient, 17% dysplastic in the control groups. These differences between the groups were statistically significant (p < 0.001). When the DDH groups were evaluated within themselves; no statistically significant difference was observed in S1 and S2 cross-sectional area, S1 and S2 maximum estimated iliosacral screw length, S1 and S2 axial and coronal angles assessment.ConclusionSacral dysplasia was more common, narrower and more angled osseous canal for the iliosacral screw was found in the DDH group. There was no relation between the degree of hip dysplasia and sacrum morphology in the DDH group. Thus, we suggest the surgeons be aware of iatrogenic injury even in constrained dysplastic hips.

Is There a Relationship Between the Functional Level of Juvenile and Adolescent Patients With Down Syndrome and Hip Dysplasia?

The prevalence of hip dysplasia among patients with Down syndrome (DS) is higher than in the general population. We hypothesize that a relationship may exist between functional level and hip dysplasia in DS, but this has not been studied to date. The aim of this study is to evaluate whether there is a relationship between functional level and radiographic parameters of hip dysplasia or other measures. Retrospective cross-sectional comparative study of 652 patients with DS from a pediatric referral center database. Patients over 8 years of age with an anteroposterior pelvis radiograph and with no exclusion criteria were selected, totaling 132 patients (264 hips; 54.55% females; mean age 12.96 ± 2.87 y). Several radiographic parameters of the acetabulum [Sharp angle (SA), Tönnis angle (TA), Wiberg center-edge angle (W-CEA), extrusion index (EI), and acetabular retroversion signs], the proximal femur [neck shaft angle (NSA)], and joint congruence [Shenton line (SL)] were assessed. Patients were classified into 2 levels based on functional skills. A multivariate association analysis was performed between radiographic parameters and functional level. Sixty-one patients were compatible with a functional level I and 71 with a level II. Forty-six hips were dysplastic and 60 were borderline according to the W-CEA. A statistically significant relationship was found between the categorical distribution of certain radiographic measurements of hip dysplasia (EI, SA, TA, W-CEA, SL, and classification by functional level ( P < 0.0005). A significant receiver operating characteristic curve was obtained for W-CEA with a cutt-off point at 26.4 degrees for level I (area under the curve = 0.763; P < 0.005; sensitivity = 0.800 and specificity = 0.644). There was a fairly high correlation between EI and TA (0.749; P < 0.0005), EI and W-CEA (-0.817; P < 0.0005), and TA and W-CEA (-0.748; P < 0.0005). Numerous hips showed signs of acetabular retroversion, with no significant differences found between functional levels or association with hip dysplasia measures. The present study reveals a relationship between an increased risk of hip dysplasia and reduced functional levels in DS children older than 8 years. These findings may guide individualized clinical follow-up of hip development in DS children considering their functional level. Level III, retrospective comparative study.

Pubic Symphysis to Sacrococcygeal Joint: A Poor Correlate to Other Spinopelvic Measurements

BackgroundThe hip-spine relationship is increasingly recognized as critical for optimizing stability following total hip arthroplasty (THA). However, these measurements are not routinely obtained during THA workup. It has been suggested that insight can be gained from supine antero-posterior pelvis radiograph, measuring the distance from the superior border of the pubic symphysis to the sacro-coccygeal joint (PSCD). This study assessed the correlation between PSCD and lateral lumbar radiographic metrics in a cohort of preoperative THA patients. MethodsWe retrospectively evaluated 250 consecutive patients who underwent THA with preoperative supine antero-posterior pelvis and lateral lumbar radiographs. The mean age was 68 years (range, 42 to 89), 61% were women, and the mean body mass index was 30 kg/m2 (range, 19 to 52). Two reviewers measured PSCD, pelvic tilt (PT), sacral slope (SS), pelvic incidence (PI), and lumbar lordosis (LL). Inter-observer reliability was calculated for all measurements, and correlation coefficients were calculated for PSCD with respect to PT, SS, PI, and LL. ResultsCorrelations between PSCD and lumbar radiographic metrics were all statistically significant, except for PI in men but graded as “weak” or “very weak” for men and women, respectively, as follows: PT = −0.30 (P < .01) and −0.46 (P < .01); SS = 0.27 (P < .01) and 0.22 (P < .01); PI = −0.04 (P = .70) and −0.19 (P = .02); and LL = 0.45 (P < .01) and 0.30 (P < .01). Inter-observer reliability was graded as “strong” for every metric. ConclusionThe PSCD was weakly correlated with all evaluated lateral lumbar radiographic metrics in both sexes, despite strong inter-observer reliability. Therefore, PSCD cannot reliably serve as a proxy for evaluating the hip-spine relationship.

Measurement of pelvic tilt and rotation on AP radiographs using HipRecon: Validation and comparison to other parameters.

In this paper, we present and evaluate HipRecon, a noncommercial software package that simultaneously calculates pelvic tilt and rotation from an anteroposterior pelvis radiograph. We asked: What is the (1) accuracy and precision, (2) robustness, and (3) intra-/interobserver reliability/reproducibility of HipRecon to analyze both pelvic tilt and rotation on conventional AP pelvis radiographs? (4) How does the prediction of pelvic tilt on AP pelvis radiographs using HipRecon compare to established measurement methods? We compared the actual pelvic tilt of 20adult human cadaveric pelvises with the calculated pelvic orientation based on an AP pelvis radiograph using HipRecon software. The pelvises were mounted on a radiolucent fixture and a total of 380 AP pelvis radiographs with different configurations were acquired. In addition, we investigated the correlation between actual tilt and the tilt calculated using HipRecon and seven other established measurement methods. The calculated software accuracy was 0.2 ± 2.0° (-3.6-4.1) for pelvic tilt and 0.0 ± 1.2° (-2.2-2.3, p = 0.39) for pelvic rotation. The Bland-Altman analysis showed values that were evenly and randomly spread in both directions. HipRecon showed excellent consistency for the measurement of pelvic tilt and rotation (intraobserver intraclass-correlation coefficient[ICC]: 0.99 [95% CI: 0.99-0.99] and interobserver ICC 0.99 [95% CI: 0.99-0.99]). Of all eight analyzed methods, the highest correlation coefficient was found for HipRecon (r = 0.98, p < 0.001). In the future, HipRecon could be used to detect changes in patient-specific pelvic orientation, helping to improve clinical understanding and decision-making in pathologies of the hip.

Radiographic Parameters of Adult Hip Dysplasia.

As knowledge about the origin and morphologic characteristics of hip pain in the young adult has evolved, so too has the clinician's ability to assess for various pathologies of the hip on radiographs, magnetic resonance imaging (MRI)/magnetic resonance arthrography (MRA), and computed tomography (CT). Because there is no algorithm at this time directly indicating what to do in more subtle hip morphologies, such as microinstability and borderline hip dysplasia (BHD), a skilled hip preservation specialist must use multiple imaging sources and know how to interpret them correctly. Imaging parameters used in the workup for hip dysplasia and BHD include the lateral center-edge angle, Tönnis angle, iliofemoral line, and presence of an upsloping lateral sourcil or everted labrum, among many others. The purpose of this narrative review was to detail various established criteria and parameters on anteroposterior pelvis plain radiographs, MRI/MRA, and CT that assist in defining the nature and severity of instability present in a dysplastic hip, thereby aiding in the development of patient-specific surgical treatment plans.

Can modified Dunn radiographs be an alternative to standing AP pelvis radiographs in the evaluation of pincer femoroacetabular impingement?

The purpose of this study was to compare modified Dunn radiographs with standing anteroposterior (AP) pelvis radiographs in respect of the tilt ratio, lateral centre-edge angle (LCEA), crossover sign, crossover percentage and joint space width measurements. The study hypothesis was that modified Dunn radiographs could be an alternative method to standing AP pelvis images in the evaluation of pincer-type femoroacetabular impingement (FAI). The study included 31 patients with a mean age of 42 years (range: 29-55 years) who had modified Dunn and standing AP pelvis radiographs taken in the radiological evaluation of non-traumatic hip pain between July 2018 and September 2022. Similar tilt ratio values were obtained on standing AP and modified Dunn images (P = 0.986). Joint space width showed a decrease in the transition from the modified Dunn position to the standing position, but the difference was not statistically significant (P = 0.161). The mean LCEA was measured as 34° ± 4° in the standing position and as 35° ± 5° in the modified Dunn position. No statistically significant difference was determined in the number of patients with a crossover sign or the crossover percentage values in these patients (P > 0.05). The data obtained in this study showed that there was no significant difference between images taken in the standing and modified Dunn positions in respect of radiological findings of pelvic tilt and pincer-type FAI. The modified Dunn radiograph is equivalent to the standing AP pelvis radiograph for the evaluation of pincer FAI.

Creating High Fidelity Synthetic Pelvis Radiographs Using Generative Adversarial Networks: Unlocking the Potential of Deep Learning Models Without Patient Privacy Concerns

BackgroundIn this work, we applied and validated an artificial intelligence technique known as generative adversarial networks (GANs) to create large volumes of high-fidelity synthetic anteroposterior (AP) pelvis radiographs that can enable deep learning (DL)-based image analyses, while ensuring patient privacy. MethodsAP pelvis radiographs with native hips were gathered from an institutional registry between 1998 and 2018. The data was used to train a model to create 512 × 512 pixel synthetic AP pelvis images. The network was trained on 25 million images produced through augmentation. A set of 100 random images (50/50 real/synthetic) was evaluated by 3 orthopaedic surgeons and 2 radiologists to discern real versus synthetic images. Two models (joint localization and segmentation) were trained using synthetic images and tested on real images. ResultsThe final model was trained on 37,640 real radiographs (16,782 patients). In a computer assessment of image fidelity, the final model achieved an “excellent” rating. In a blinded review of paired images (1 real, 1 synthetic), orthopaedic surgeon reviewers were unable to correctly identify which image was synthetic (accuracy = 55%, Kappa = 0.11), highlighting synthetic image fidelity. The synthetic and real images showed equivalent performance when they were assessed by established DL models. ConclusionThis work shows the ability to use a DL technique to generate a large volume of high-fidelity synthetic pelvis images not discernible from real imaging by computers or experts. These images can be used for cross-institutional sharing and model pretraining, further advancing the performance of DL models without risk to patient data safety. Level of EvidenceLevel III.

Femoral neck shaft angle measurement on plain radiography: is standing or supine radiograph a reliable template for the contralateral femur?

IntroductionNeck-shaft angle (NSA) is of paramount importance to orthopedic surgeons due to its implications for various pathologies of the hip and femur. The primary aim of the study was to establish if NSA measurement may be affected by imaging position (standing and supine) and provide evidence regarding whether the contralateral NSA can be used as a template. The secondary aim was to determine a reference value and precisely understand the effects of sex on NSA measurement.Materials and methodsWe measured bilateral NSA in a retrospective study of 200 standing and 200 supine anteroposterior pelvis radiographs that met the inclusion criteria, while paying special attention to bilateral hip symmetry. The overall inter-rater reliability was 0.688 (CI 0.128–0.851). Matching was performed according to sex (exact matching) and age. Paired t-test, Pearson correlation coefficient, and independent sample t-test were used (p < 0.01).ResultsA total of 400 pairs of femoral necks were reviewed, comprising of 200 males and 200 females. In the upright radiograph, the overall mean NSA was 131.21° ± 4.72°. There was no significant difference between right and left femur NSA among the patients (p = 0.95). On both sides, male NSA was higher than female NSA (p < 0.001). In supine radiograph, the overall mean NSA for the supine position was 133.06° ± 5.71°. There was a significant difference between NSA of the right and left femur among the patients in the supine position (p < 0.001). On supine radiographs there was no statistically significant difference between male and female NSA (p = 0.85).ConclusionOur findings indicated no significant variability in upright radiographs between the right and left NSA. In contrast, significant asymmetry between the right and left NSA was found in the supine radiographs. However, this study does not provide definitive clinical evidence, and further clinical-oriented research is required.Level of evidenceLevel III; retrospective comparative study.

Estimation of Gender from Anteroposterior Pelvis Radiograph among Nepalese population

Estimation of Gender from Anteroposterior Pelvis Radiograph among Nepalese population

Value of neutrophil-to-lymphocyte ratio in predicting surgical intervention for hydronephrosis during pregnancy.

We aimed to examine the hematological parameters of pregnant patients with ureteral stones that require intervention. Medical data of patients presenting to urology department between October 2018 and December 2020 were retrospectively analyzed. Patients with flank pain associated with hydronephrosis were included in the study and divided into two groups according to whether an intervention was performed or not (Group-1, Group-2). Ureterorenoscopy (URS) or ureteral stent placement was performed as intervention. Demographic data, complete blood count (CBC), urine analysis, and ultrasonographic findings were collected. Gestational age (week), number of pregnancies, maternal age (years), Anteroposterior pelvis diameter (mm), VAS (Visual Analog Scale) (range 1-10) and mean platelet volume (MPV) were collected from the patient file. Inflammatory markers including neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were computed. About 35 patients were included in Group-1 and 52 patients in Group-2. Ureterorenoscopy was performed in 21/35 (60%) patients, and ureteral stents were placed in 14/35 (40%) patients. None of the patients experienced complications. There was no statistical difference between these two groups in terms of maternal age, gestational age, number of pregnancies, pelvis diameter, PLR, and MPV. VAS and NLR were statistically higher in group-1 (p < 0.05). According to the Receiver operating characteristic curve analysis performed for the prediction of ureteral stone presence, the best cut-off point for the NLR 4.153 (sensitivity 80%, specificity 80.6%, area under curve (AUC): 0.824). We think that NLR can be used to determine the group that needs to be intervented due to ureteral stones in patients with symptomatic hydronephrosis during pregnancy.