Radiographs Of Femur Research Articles

AFFnet - a deep convolutional neural network for the detection of atypical femur fractures from anteriorposterior radiographs

Despite well-defined criteria for radiographic diagnosis of atypical femur fractures (AFFs), missed and delayed diagnosis is common. An AFF diagnostic software could provide timely AFF detection to prevent progression of incomplete or development of contralateral AFFs. In this study, we investigated the ability for an artificial intelligence (AI)-based application, using deep learning models (DLMs), particularly convolutional neural networks (CNNs), to detect AFFs from femoral radiographs. A labelled Australian dataset of pre-operative complete AFF (cAFF), incomplete AFF (iAFF), typical femoral shaft fracture (TFF), and non-fractured femoral (NFF) X-ray images in anterior-posterior view were used for training (N = 213, 49, 394, 1359, respectively). An AFFnet model was developed using a pretrained (ImageNet dataset) ResNet-50 backbone, and a novel Box Attention Guide (BAG) module to guide the model's scanning patterns to enhance its learning. All images were used to train and internally test the model using a 5-fold cross validation approach, and further validated by an external dataset. External validation of the model's performance was conducted on a Sweden dataset comprising 733 TFF and 290 AFF images. Precision, sensitivity, specificity, F1-score and AUC were measured and compared between AFFnet and a global approach with ResNet-50. Excellent diagnostic performance was recorded in both models (all AUC >0.97), however AFFnet recorded lower number of prediction errors, and improved sensitivity, F1-score and precision compared to ResNet-50 in both internal and external testing. Sensitivity in the detection of iAFF was higher for AFFnet than ResNet-50 (82 % vs 56 %). In conclusion, AFFnet achieved excellent diagnostic performance on internal and external validation, which was superior to a pre-existing model. Accurate AI-based AFF diagnostic software has the potential to improve AFF diagnosis, reduce radiologist error, and allow urgent intervention, thus improving patient outcomes.

Analysis of femur radiographs for osteoporosis detection using anisotropic Morlet wavelet transform and discrete wavelet transform

Analysis of femur radiographs for osteoporosis detection using anisotropic Morlet wavelet transform and discrete wavelet transform

Investigating femoral growth disruption in subadults from the 10th-13th century St. Étienne cemetery of Toulouse, France.

The skeleton embodies an individual's environment and lived experiences. Studying childhood growth disruption can, therefore, aid in understanding the experiences of children in the past. This study evaluates growth disruption in a medieval Toulousian subadult sample to explore factors that may have influenced childhood growth and mortality at this site and to assess the utility of Harris line (HL) interpretations in bioarchaeology. Femoral growth disruption was assessed in n = 71 subadults (0.125-12.42 years) from the 10th-13th century St. Étienne cemetery of Toulouse, France, using femoral length, total area, cortical area, and relative cortical area. Femoral radiographs were assessed for HLs. To determine the prevalence of growth disruption, z-scores were calculated using data from the Denver growth study. The majority of subadults in this sample suffered from femoral growth disruption. Young children (1.0-3.99 years) were the most affected, with >65% experiencing reduced appositional growth and linear growth stunting at time-of-death. Additionally, while many individuals presented with observable HLs, linear and appositional growth did not significantly differ between individuals with and without HLs. Maternal malnutrition and inadequate complementary feeding practices likely contributed to the high prevalence of growth disruption among the youngest individuals in the study. The older children and adolescents buried at St. Étienne experienced an amelioration in growth deficits, indicating an improvement in nutrition and/or disease load. The results of this study suggest that more consideration is required when interpreting the presence/absence of HLs, and that studies assessing HLs may benefit from using a more individualistic approach.

Pengaruh Variasi mAs terhadap Densitas pada Hasil Radiograf Os Femur

Background: The human body's anatomical structure may be seen in radiological image findings. The proper exposure factor must be given in order to produce radiographic findings. The amperage value times the exposure period is equal to mAs. A darker image will result from a larger mA factor or longer exposure time. However, by choosing the appropriate exposure factor, an optimal radiograph density can be produced that can clearly display the difference in thickness and density between organs. The purpose of this study is to determine the results of how density affects the results of radiographs of the os femur.Methods: This research is quantitative using experimental methods to find out how the effect of mAs variations and how much the range of changes in value on density in AP projection femur examinations using mAs variations namely mAs 4, 8, 10, 12, 20, 25, and 32 with a fixed kV of 70 kV.Results: The results of this study indicate that there is a change in the effect of density quality on the variation of mAs on the radiograph results of the femoral os using the Friedman test p-value 0.001 which means less than 0.05. And the range of changes in density values at the caput femur, collum femur, collum femur, and greater trochanter there are changes in each mAs variation. The value of density variation against 7 mAs variations in radiograph results at variations of 4 to 32 mAs shows the density value increases by 0.14, for the range of increase in each variation it is ± from 0.02 to 0.05.Conclusions: The purpose of this study is to determine the results of how density is affected and the results of how the range of changes in density values on femur radiographs.

Accuracy of Caudocranial Canine Femoral Radiographs Compared to Computed Tomography Multiplanar Reconstructions for Measurement of Anatomic Lateral Distal Femoral Angle.

This study aimed to compare the accuracy of sternal recumbency caudocranially obtained radiographs of canine femora to computed tomographic (CT) frontal plane reconstructions of the same femora for assessing anatomic distal lateral femoral angles (aLDFA). Multicentre, retrospective study utilizing 81 matched radiographic and CT studies of clinical patients undergoing assessment for various issues were reviewed. Anatomic lateral distal femoral angles were measured, and accuracy assessed with descriptive statistics and Bland-Altman plot analysis, with CT considered the reference standard. Sensitivity and specificity of a cut-off for measured aLDFA (102 degrees) were determined to assess radiography as a screening tool for significant deformity. Radiographs on average overestimated aLDFA by 1.8 degrees compared to CT. Bland-Altman analysis identified a 15.4 degrees 95% limit of agreement range and a tendency for greater overestimation at higher average measured value. Radiographic measurement of aLDFA of 102 degrees or less had a 90% sensitivity, 71.83% specificity, and 98.08% negative predictive value for the CT measurement being less than 102 degrees. Accuracy of aLDFA measurement by caudocranial radiographs does not demonstrate sufficient accuracy when compared to CT frontal plane reconstructions with unpredictable differences. Radiographic assessment is a useful screening tool to exclude animals with a true aLDFA of greater than 102 degrees with a high degree of certainty.

Atypical femoral fracture mimicking lumbar radiculopathy in two patients taking bisphosphonate long-term: A case report

BackgroundAtypical femoral fracture (AFF) is a rare complication in patients with osteoporosis undergoing long-term bisphosphonate therapy. The most common symptom of incomplete AFF is nonspecific thigh pain, which is often difficult to distinguish from other causes.Case presentationWe present two cases of AFF misdiagnosed as lumbar radiculopathy. Both patients visited our hospital for thigh pain, and in both cases the findings of lumbar spine magnetic resonance imaging showed substantial nerve compression. These patients had been treated for lumbar radiculopathy, but localized symptoms became conspicuous and femoral radiographs revealed complete AFF. The initial radiographs were reviewed retrospectively and revealed slight lateral cortical thickening in the affected femur, denoting a missed incomplete AFF. Internal fixation with intramedullary nails was performed.ConclusionsAFF may mimic lumbar radiculopathy. Therefore, clinicians should consider AFF as a differential diagnosis in older patients with lumbar canal stenosis who are undergoing long-term bisphosphonate therapy and present with thigh pain.

Sagittal mechanical ratio: A novel technique to define sagittal alignment of the femur independent of distal anatomic landmarks

BackgroundRadiographic measurements to study sagittal alignment in the setting of knee are frequently difficult to evaluate due the presence of a prosthesis or implant that obscures traditional radiographic landmarks. In this paper we present a novel method of determining sagittal femoral alignment in the presence of obscuring implants. Methods98 full-length femoral radiographs were reviewed and divided into two groups. In Group 1, the Distal Mechanical Point (DMP) was used to calculate the Distal Mechanical Ratio (DMR), defined as the ratio of the linear distance from the DMP to the anterior cortical axis divided by the distance from the anterior cortical axis to posterior condylar cortex. In group 2, the sagittal mechanical axis was measured using the true DMP (tDMP) and then separately measured using the DMR to find the calculated DMP (cDMP), and the angular variance between the calculated (cSMA) and true (tSMA) sagittal mechanical axis was calculated, as well as the linear distance between the tDMP and cDMP. Twenty additional patients with knee replacements were then selected and two observers used a cSMA to determine a femoral prosthesis flexion angle (FPFA), with intraobserver correlation calculated. ResultsThe mean DMR was found to be 0.24, with high intraobserver correlation and normal distribution. Validation of the model demonstrated angular variance between tSMA and cSMA less than 1 degree and linear distance between tDMP and cDMP less than 1 mm. Calculation of cCMA in the presence of total knee arthroplasty revealed very strong intraobserver correlation of 0.89. ConclusionThe Distal Mechanical Ratio reliably predicted the true Sagittal Mechanical Axis within 1 degree and true Distal Mechanical Point within 1 mm, indicating that it may be a valuable tool for evaluating sagittal femoral alignment in cases where anatomic landmarks may be absent or obscured.

Diagnostic value of full-length femur radiographs in patients with neck of femur fracture and co-existing malignancy.

In the UK, it is common practice to obtain full-length femur radiographs in patients admitted with neck of femur fractures (NOF) and co-existing malignancy. Limited literature exists studying this topic. Our aim was to identify whether full-length femur radiographs are of diagnostic and therapeutic value in this demographic. A retrospective observational analysis of the patients admitted with a neck of femur fracture over a 5-year period (2015-2020) using the National Hip Fracture Database was performed at a major trauma centre. Electronic patient records were accessed to screen the NOF patients who had co-existing malignancy and subsequently underwent a full-length femur radiograph. In addition to patient demographics, we also identified the plan and whether it was affected by findings of the full-length radiograph, the operation performed, any additional investigations undertaken for malignancy, the type of cancer, complications and 1-year mortality. Of the 2416 patients screened, 18% had a co-existing malignancy (n = 431). Of the 431 with underlying malignancy, 424 patients underwent a full-length femur radiograph while only seven of these radiographs identified lesions. From the seven patients with findings of metastatic deposits on full-length radiographs, none required an alternative operation to that which they normally would undergo. Furthermore, no patients required a longer stem arthroplasty or longer internal fixation. One in four fractures was associated with co-existing breast malignancy (26.5%, n = 114), followed by prostate cancer (14.8%, n = 64). Colorectal, lung, bladder and skin (squamous cell carcinoma) contributed 6-10% (n = 44, 40, 33, 29, respectively). Other malignancies contributed to the rest of the 25%. To conclude, full-length radiographs had no diagnostic or therapeutic value in our cohort of patients regardless of the full-length femur findings.

Cortical Thickness of Proximal Femur as a Preliminary Indicator of Bone Mineral Density

Background: Osteoporosis progresses with advancing age. Estimation of bone mineral density (BMD) using dual energy X-ray absorptiometry (DXA) is valuable in predicting fracture risk in the elderly. DXA machines however may not always be available in under-resourced developing countries. Aim: To find values of CTI and CFI in normal adult young and old, male and female population of Southern Punjab. Study design: Cross-sectional population study Methods: Measurements were recorded from 107 anteroposterior radiographs of proximal femur of normal adult male and female subjects divided in two groups: Young: 22 male and 26 females with mean age 28±3.4 and Old: 31 male and 28 females with mean age 61+5.2. Results: Statistical comparison between male and female subjects for CTI was not significant in the Y and O groups. Similar comparison for CFI while not significant in the Y-group was highly significant in the O-group. In overall comparison of Y and O groups the difference was very highly significant for CTI and CFI; both showing higher values in the Y-group. Conclusion; CTI and CFI measured from radiographs of proximal femur are reliable parameters and can be recommended for preliminary assessment of bone mineral density in developing countries. Keywords: Proximal femur, morphometry, cortical thickness index (CTI), canal flare index (CFI), bone mineral density

Subtrochanteric fractures: case report

Background: Subtrochanteric fractures account for around 7% to 34% of all femur fractures. Cephalo-medullary nailing is the gold standard in the repair of subtrochanteric femur fractures. Case presentation: We present a case of a medically free 21-year-old man, who was admitted with right thigh deformity and inability to bear weight after a motor vehicle accident. Standard pelvis and right femur radiographs showed a subtrochanteric femur with deformity forces of the fracture fragments. The patient was operated on with cephalo-medullary nailing using a Lowman bone holder. The fracture remained stable after cephalo-medullary fixation. The patient was discharged and was advised to continue follow-up. Conclusion: Fixation of femur subtrochanteric fracture with cephalo-medullary nailing technique using a Lowman clamp showed excellent clinical and radiographic results and a low complication rate.

Curriculum learning for improved femur fracture classification: Scheduling data with prior knowledge and uncertainty.

An adequate classification of proximal femur fractures from X-ray images is crucial for the treatment choice and the patients' clinical outcome. We rely on the commonly used AO system, which describes a hierarchical knowledge tree classifying the images into types and subtypes according to the fracture's location and complexity. In this paper, we propose a method for the automatic classification of proximal femur fractures into 3 and 7 AO classes based on a Convolutional Neural Network (CNN). As it is known, CNNs need large and representative datasets with reliable labels, which are hard to collect for the application at hand. In this paper, we design a curriculum learning (CL) approach that improves over the basic CNNs performance under such conditions. Our novel formulation reunites three curriculum strategies: individually weighting training samples, reordering the training set, and sampling subsets of data. The core of these strategies is a scoring function ranking the training samples. We define two novel scoring functions: one from domain-specific prior knowledge and an original self-paced uncertainty score. We perform experiments on a clinical dataset of proximal femur radiographs. The curriculum improves proximal femur fracture classification up to the performance of experienced trauma surgeons. The best curriculum method reorders the training set based on prior knowledge resulting into a classification improvement of 15%. Using the publicly available MNIST dataset, we further discuss and demonstrate the benefits of our unified CL formulation for three controlled and challenging digit recognition scenarios: with limited amounts of data, under class-imbalance, and in the presence of label noise. The code of our work is available at: https://github.com/ameliajimenez/curriculum-learning-prior-uncertainty.

Femur morphology in healthy infants and young children.

The objective of this study was to characterize femur morphology in healthy infants and young children. Anterior-posterior (AP) radiographs of the femur from children age 0-3 years with no history of bone disease were obtained from two children's hospitals and one medical examiner's office. Femur morphological measures (bone length, minimum diaphysis diameter, growth plate width, and femur radius of curvature) and sectional structural measures were determined. Measures were described and compared based on subject age and mass. Relationships between measures and age and mass were evaluated. The 169 AP femur radiographs were obtained from 99 children (59.6% males, median age=12.0months, IQR=0-27.5months, median body weight=10.0kg, IQR=4.4-15.6kg). Femur length (rs = 0.97, p< 0.001; rs = 0.89, p< 0.001), trochanter width (rs = 0.86, p< 0.001; rs = 0.85, p< 0.001), minimum diaphysis diameter (rs = 0.91, p< 0.001; rs = 0.87, p< 0.001), and growth plate width (rs = 0.91, p< 0.001; rs = 0.84, p< 0.001) increased with age and weight, respectively. Cross-sectional area (rs = 0.87; rs = 0.86; p< 0.01), polar moment of inertia (rs = 0.91; rs = 0.87; p< 0.001), moment of inertia (rs = 0.91; rs = 0.87; p< 0.001), polar modulus (rs = 0.91; rs = 0.87; p< 0.001) and medullary canal diameter (rs = 0.83, p< 0.001; rs = 0.73, p< 0.001) at the minimum diaphysis also increased with age and weight, respectively. Changes during rapid bone growth are important to understanding fracture risk in infants and young children as they transition to independent walking. Femur length, trochanter width, minimum diaphysis diameter and growth plate width increased with age and weight. Structural properties associated with fracture resistance also increased with age and weight.

Sensitivity and specificity of modified RUST score using clinical and radiographic findings as a gold standard.

AimsThe modified Radiological Union Scale for Tibia (mRUST) fractures score was developed in order to assess progress to union and define a numerical assessment of fracture healing of metadiaphyseal fractures. This score has been shown to be valuable in predicting radiological union; however, there is no information on the sensitivity, specificity, and accuracy of this index for various cut-off scores. The aim of this study is to evaluate sensitivity, specificity, accuracy, and cut-off points of the mRUST score for the diagnosis of metadiaphyseal fractures healing.MethodsA cohort of 146 distal femur fractures were retrospectively identified at our institution. After excluding AO/OTA type B fractures, nonunions, follow-up less than 12 weeks, and patients aged less than 16 years, 104 sets of radiographs were included for analysis. Anteroposterior and lateral femur radiographs at six weeks, 12 weeks, 24 weeks, and final follow-up were separately scored by three surgeons using the mRUST score. The sensitivity and specificity of mean mRUST score were calculated using clinical and further radiological findings as a gold standard for ultimate fracture healing. A receiver operating characteristic curve was also performed to determine the cut-off points at each time point.ResultsThe mean mRUST score of ten at 24 weeks revealed a 91.9% sensitivity, 100% specificity, and 92.6% accuracy of predicting ultimate fracture healing. A cut-off point of 13 points revealed 41.9% sensitivity, 100% specificity, and 46.9% accuracy at the same time point.ConclusionThe mRUST score of ten points at 24 weeks can be used as a viable screening method with the highest sensitivity, specificity, and accuracy for healing of metadiaphyseal femur fractures. However, the cut-off point of 13 increases the specificity to 100%, but decreases sensitivity. Furthermore, the mRUST score should not be used at six weeks, as results show an inability to accurately predict eventual fracture healing at this time point.Cite this article: Bone Jt Open 2021;2(10):796–805.

Validating scoring systems for fracture healing in infants and young children: pilot study

BackgroundRecent studies have analysed birth-related clavicular fractures to propose time frames for healing that could be applied to dating of all fractures in cases of suspected child abuse.ObjectiveTo assess differences in healing rates between femoral fractures and birth-related clavicular fractures in infants and young children.Materials and methodsA retrospective 5-year pilot study of femoral fractures in children younger than 3 years of age was performed. Anonymised radiographs were independently scored by two radiologists for stages of fracture healing. In cases of reader disagreement, radiographs were independently scored by a third radiologist.ResultsIn total, 74 radiographs (30 children) met the inclusion criteria. Fracture healing evolved over time with subperiosteal new bone formation (SPNBF) appearing first, followed by callus then remodelling. A power calculation for a single proportion, with a level of confidence of 95% and a margin of error of 5%, showed that in a definitive study, 359 radiographs would be required.ConclusionAlthough the overall pattern of healing is similar, in this small pilot study, the earliest times for SPNBF and callus formation in femoral fractures appeared to lag behind healing of birth-related clavicular fractures. Remodelling appeared earlier than remodelling of clavicular fractures. A power calculation has determined numbers of femoral radiographs (359) required for a definitive study.

3D-surface scan based validated new measurement technique of femoral joint line reconstruction in total knee arthroplasty

PurposeThis study aimed to validate a new joint line measurement technique in total knee arthroplasty for separated assessment of the medial and lateral femoral joint line alteration with 3D-surface scan technology. Separate assessment of the medial and lateral joint line alteration may improve TKA alignment assessment regarding to joint line restoration in kinematic alignment and use of robotic-assisted TKA surgery.MethodsThe medial and lateral joint line difference after TKA implantation on an artificial bone model was analyzed and compared with a 3D-scan and full femoral radiographs pre- and postoperatively. Radiographic analysis included the perpendicular distance between the most distal point of the medial and lateral condyle and the reproduced preoperative lateral distal femoral angle (LDFA). For evaluation of validity and reliability, radiographs were captured initially with true anteroposterior view and subsequently with combined flexion and rotation malpositioning. Reliability of the introduced measurement technique in between three observers was tested with intraclass correlation coefficient (ICC).ResultsRadiographic measurement showed a mean difference of 0.9 mm on the medial side and 0.6 mm on the lateral side when compared to the 3D-surface scan measurement. The reliability of measurement accuracy was ≤ 1 mm in x-rays with < 10° flexion error regardless to malrotation in these images. The ICC test showed very good reliability for the medial joint line evaluation and good reliability for lateral joint line evaluation (ICC 0.92, ICC 0.86 respectively).ConclusionThe new introduced joint line measurement method showed a sufficient reliability, accuracy and precision. It provides separated information about medial and lateral joint line alteration in TKA surgery in absolute values.Level of evidenceV - Experimental Study

Emphysematous osteomyelitis diagnosed on Tc99m MDP SPECT-CT scintigraphy: a case report

Background: Emphysematous osteomyelitis is a rare but fatal condition, caused by gas-forming bacteria. We reported a rare case of emphysematous osteomyelitis of left femur in a 27-year-old diabetic male, diagnosed on Tc99m methylene diphosphonate (MDP) single photon emission computed tomography-computed tomography (SPECT-CT) scintigraphy. The pattern of uptake in emphysematous osteomyelitis on Tc99m MDP SPECT-CT scintigraphy was not reported previously. Case Presentation: A 27-year-old diabetic male patient presented with history of pain in left thigh and fever for 10 days. He was referred to nuclear medicine department for Tc99m MDP bone scan. He had no history of trauma or surgery, and his radiograph of left femur was unremarkable at presentation. Tc99m MDP SPECT-CT scintigraphy showed abnormal uptake in femur with intraosseous air, pathognomic of emphysematous osteomyelitis. Further imaging by magnetic resonant imaging (MRI) showed edematous changes in the musculature of left thigh with marrow replacement changes in left femur favoring the diagnosis of emphysematous osteomyelitis. However, no bacterial growth was detected on blood culture due to prior administration of intravenous antibiotics. Conclusion: Tc99m MDP SPECT-CT scintigraphy is helpful in diagnosis of such rare conditions like emphysematous osteomyelitis, in addition to common pathologies of bone. Furthermore, this report is helpful for nuclear physicians to know about the pattern of uptake on planner bone scan and SPECT-CT images in such a rare infection of bone, by gas forming bacteria.

Comparative study of dynamic hip screw versus proximal femoral nailing in the management of intertrochanteric fracture femur

DHS with side plate assembly is most commonly used device for fixation of intertrochanteric fractures. It is a non collapsible fixation device, which permits the proximal fragment to collapse or settle on the fixation device seeking its own position of stability. After the patient with intertrochanteric fracture was admitted to hospital all the necessary clinical details were recorded in proforma prepared for this study. After the completion of the hospital treatment patients were discharged and called for follow up at out patient level, at regular intervals for serial clinical and radiological evaluation. All patients were followed up at 2 weeks interval till fracture union, at 12 weeks and at 6 months post operatively. 5 patients failed to attend the first follow up and were lost for further follow up (3 cases of DHS and 2 PFN). At each follow up radiographs of upper femur and hip were taken to assess the fracture union, implant failure and screw cut out. In our series of 30 patients 5 cases were lost for follow up and 2 cases expired due to associated medical problems.

Does Femoral Morphology Predict the Risk of Periprosthetic Fracture After Cementless Total Hip Arthroplasty?

BackgroundPeriprosthetic femur fracture remains a leading mode of early failure following cementless total hip arthroplasty (THA). The purpose of this study is to determine if a specific femoral morphology is associated with an increased risk of acute, periprosthetic fracture after cementless THA. MethodsAn institutional arthroplasty registry was used to identify 32 primary, cementless THAs revised for acute, postoperative periprosthetic fracture (“fracture” cohort) within 3 months of the index procedure. Patients were matched 1:2 to 64 THAs without fracture (“control” cohort) for age, body mass index, gender, and stem design. Preoperative radiographic measurements performed on anteroposterior pelvis and femur radiographs included the neck-shaft angle, endosteal width at 4 locations, and external cortical diameter at 2 locations. These measurements were used to calculate the morphological cortical index, canal flare index, canal calcar ratio, and canal bone ratio. Postoperative measurements included canal fill and stem alignment. Statistical analyses included clustered regressions, Fisher’s exact test, and Student’s t-test. ResultsThe mean endosteal width at 10 cm distal to the lesser trochanter was greater in fracture patients, although not statistically significant (P = .1). However, this resulted in differences in the canal flare index (P = .03), canal calcar ratio (P = .03), and canal bone ratio (P = .03) between the 2 cohorts. These ratios indicate decreased meta-diaphyseal taper in fracture patients. Preoperative femoral neck-shaft angle was more varus in fracture patients (P = .04). ConclusionPatients sustaining an acute, periprosthetic fracture with cementless femoral fixation after THA had thinner distal cortices and a decreased meta-diaphyseal taper.

Osteoporosis Detection Using Combined Texture Features of Proximal Femur Radiographs

Osteoporosis Detection Using Combined Texture Features of Proximal Femur Radiographs

Reliability of measuring lateral bowing angle of the femur in patients with atypical femur fractures.

Lateral femoral bowing causes a higher tensile mechanical load on the lateral side of the femur, which plays a critical role in the pathogenesis of atypical femoral fractures (AFFs). There are many ways to measure lateral femoral bowing on plain radiographs, and there are difficulties in finding a correspondence point between measurements among multiple measurers. The purpose of this study is to prove the best method of correspondence between the investigators by analyzing the reliability of various methods for measuring lateral femoral bowing. We retrospectively collected data from 85 patients (87 femurs) diagnosed with AFF who had plain radiographs of entire femur from October 2013 to March 2018. The femoral bowing was measured in coronal view of femur plain radiographs using five methods (Sasaki, Morin, Jang, Kim, and Yau) by three examiners, respectively. The intra- and interobserver reliability of each method was assessed using intraclass correlation coefficient (ICC) for continuous variables. All methods showed excellent intra- and interobserver reliability with ICC of >0.8. Among five methods, the Yau's method was the highest reliable method (ICC = 0.980, 95% confidence interval = 0.971-0.986). All methods of measuring lateral femoral bowing in the coronal plane of plain radiographs are reliable. And, we recommend Yau's method, which has a clear reference point for measuring femoral bowing and is highest reproducible.