Extreme Length Research Articles

Osteoarticular tuberculosis: imaging findings in pediatric patients.

Osteoarticular tuberculosis (TB) is an uncommon form of extrapulmonary TB that has the potential to damage joints and bones, generating long-term impairment. Mainly, the initial diagnosis of osteoarticular TB relies on clinical findings and imaging. When required, imaging can aim for less invasive tissue or fluid sampling for pathology, microbiology, and molecular biology analysis. Most TB diagnosis tests have variable and frequently poor sensitivities; however, bone biopsy samples have demonstrated a high percentage of culture positivity. Clinical and imaging findings of osteoarticular TB often mimic other processes, such as rheumatoid arthritis or chronic recurrent multifocal osteomyelitis. When the infection affects the growth plates, angular deformities and extremity length discrepancies can arise. Unfortunately, several osteoarticular TB cases are detected late due to the nonspecific nature of clinical symptoms and non-characteristic imaging findings. This article reviews the most common and atypical osteoarticular TB imaging presentations to increase awareness of osteoarticular TB.

Supernumerary Head of the Biceps Brachii Muscle Influences the Topography of the Coracobrachialis and Biceps Brachii Muscles

Background/Objectives: Anatomical variations in the biceps brachii muscle (BBM) are extremely frequent, leading to developmental and clinical implications. We studied the topography of the BBM and analyzed its correlations with other structures in the brachial region. Methods: A total of 103 cadaveric upper extremities were dissected. The length of the upper extremities was utilized as a reference line. The origin and insertion of the BBM, the coracobrachialis muscle (CBM), and the related neurovascular system were evaluated. Results: Each variable was calculated as a percentile and compared according to the presence of the considered variation; in particular, a supernumerary head of the BBM was found in 12/103 (11.65%) of upper extremities and was associated with a longer upper limb (506.25 ± 32.55 mm vs. 484.27 ± 30.41 mm, p = 0.022). When the variables were standardized by the length of the upper limb, the accessory head of the BBM was associated with the distal insertion point of the CBM (28.18 ± 3.54% vs. 30.59 ± 2.94%, p = 0.011) and BBM length (55.11 ± 2.17% vs. 58.18 ± 3.72%, p = 0.006). Other variables did not present significant differences with respect to the presence of the supernumerary head of the BBM. Conclusions: BBM variations may affect the topography of other structures, such as the length of the upper extremities, insertion of the CBM, and length of the BBM. Further studies are required to elucidate its clinical implications.

Mismatch between fixed classroom furniture and anthropometric measurements among university students: Relationships to ergonomic risk.

Appropriate arrangement of classroom ergonomics is necessary for maintaining health and improving academic performance, learning, and motivation. We aimed to determine the anthropometric measurements and ergonomic risk levels of students during a handwriting activity on a fixed desk and chair and to analyze the mismatch and relationships between these factors. This study included 149 university students (female:73, male:76). Anthropometric measurements (lower and upper extremity length, shoulder height, elbow-rest height, hip-popliteal length, popliteal height, knee height, the distance between tragus and wall, and between acromion and wall) were done with a tape measure. The Rapid Upper Limb Assessment (RULA) tool was conducted to determine the ergonomic risk level while students wrote a standard text on a fixed desk and chair as if they were taking notes in the classroom. The mismatch was evaluated between backrest height and sitting shoulder height, seat height, and popliteal height. The Pearson Chi-Square and the Spearman Correlation test were used for statistical analysis. The median values of the participants' age, height, weight, and BMI were 22 years, 1.70 m, 68 kg, and 23.18 kg/cm2, respectively. Most students had inadequate ergonomic posture while writing on fixed furniture at the university (Median RULA grand score: 4). More mismatches for seat height (54.4%) were found in high ergonomic risk levels but mismatches for backrest height did not follow a similar result. More investigation should be conducted with prospective studies including interventions like adjustable furniture.

The impact of volume and neonatal level of care on outcomes of moderate and late preterm infants.

Evaluate the relationship of neonatal unit level of care (LOC) and volume with mortality or morbidity in moderate-late preterm (MLP) (32-36 weeks' gestation) infants. Retrospective cohort study of 650,865 inborn MLP infants in 4976 hospitals-years using 2003-2015 linked administrative data from 4 states. Exposure was combined neonatal LOC and MLP annual volume. The primary outcome was death or morbidity (respiratory distress syndrome, severe intraventricular hemorrhage, necrotizing enterocolitis, sepsis, infection, pneumothorax, extreme length of stay) with components as secondary outcomes. Poisson regression models adjusted for patient characteristics with a random effect for unit were used. In adjusted models, high-volume level 2 units had a lower risk of the primary outcome compared to low-volume level 3 units (aIRR 0.90 [95% CI 0.83-0.98] vs. aIRR 1.13 [95% CI 1.03-1.24], p < 0.001) CONCLUSION: MLP infants had improved outcomes in high-volume level 2 units compared to low-volume level 3 units in adjusted analysis.

Incidence and biomechanical risk factors for running-related injuries: A prospective cohort study

BackgroundInjuries among runners is significant, yet the contributing risk factors remain elusive. The objective of this study was to examined the incidence and biomechanical elements associated with running-related injuries. MethodsA 24-week prospective study was carried out. Injury incidence was calculated per 1000 h of running, with participants completing bi-monthly online questionnaires. Biomechanical risk factors, encompassing plantar pressure, muscle strength of hip and knee muscles, core stability, dorsiflexion, passive hip internal rotation, lower extremity length, Q-angle, and shank-forefoot alignment, were assessed at baseline. Logistic regression was used to investigate the relationship between injury incidence and these biomechanical risk factors. ResultsNinety-eight runners participated in the study. Injury incidence was 8.1 per 1000 h of running, with 41 runners experiencing musculoskeletal injuries during the follow-up period. The knee emerged as the most commonly affected joint, constituting 28.4 % of injuries. The Odds Ratio for hip external rotator muscle strength was .84 (95 % Confidence Interval = .71 - .99). ConclusionGreater force during hip external rotation was identified as a protective factor against running injuries. These findings bear significance for the formulation and implementation of preventive strategies.

Investigation of the relationship between hallux valgus, quadriceps angle, and body image perception in young adults

Purpose: Our study aimed to identify the presence and severity of hallux valgus deformity in young adults, using both by the Manchester classification and goniometry, to evaluate the Quadriceps angle (Q angle), and to examine the relationship between some anatomical parameters and body image perception. Materials and Methods: A total of 158 individuals aged 18-30 (111 females, 47 males) who voluntarily agreed to participate in the study were included. Demographic characteristics, Quadriceps angle, and hallux valgus angle were measured. Hallux valgus and Quadriceps angles were determined using a goniometer, while the Manchester scale was employed to evaluate the level of Hallux valgus deformity. The Golden Ratio for the lower extremity was calculated by taking the ratio of lower extremity length to leg length, and the body image perception score was determined. Results: Body weight, height and body mass index showed statistically significant differences in terms of gender, while age parameter did not show statistically significant difference between genders. Also, no significant difference in Quadriceps angle was observed between genders for both right and left sides, while a significant difference in Hallux valgus angle was noted. A high, positive, and significant relationship was found between Manchester classification and hallux valgus, while Golden ratio values did not significantly differ by gender. Additionally, body image perception scores were higher in males (162.60±25.45 points) than in females (153.51±25.89 points). Conclusion: Deviations from their normal values of the hallux valgus and quadriceps angle which affect the musculoskeletal system, may lead to some health problems, as well as difficulties in performing daily life activities, and concerns about aesthetics. Failure to fulfil one’s normal functions or not to find oneself aesthetically insufficient will also make it likely that the body image perception will deteriorate.

Going “Beyond” Mere Transformation: Warhol and Reconciliation of the Derivative Work Right and Fair Use

The Supreme Court’s recent decision in Andy Warhol Foundation for Visual Arts, Inc. v. Goldsmith is a watershed moment in the story of copyright jurisprudence. At its broadest, the decision articulates a unified vision—one that had been dormant in the lower court fair use jurisprudence—about the role of copyright and the manner in which to make sense of its effort to balance exclusivity with its myriad limitations. This Essay focuses on how the Court reconciled the working of the statute’s derivative work right with the breadth and reach of the “transformative use” version of the fair use doctrine. The core of the Court’s reconciliation centers around three ideas. The first is the need for an independent justification for a use to even qualify for fair use. Transformation on its own does not provide such a justification, which must be instead identified independently. Related is the second idea, that the secondary use must reveal a distinct purpose. Unlike the justification element, this step is comparative and heavily contextual. And the third element is the balance between transformativeness and commerciality, which the legislative text makes clear and Campbell had gone to extreme lengths to reinforce.

Visual Feature-Guided Diamond Convolutional Network for Finger Vein Recognition.

Finger vein (FV) biometrics have garnered considerable attention due to their inherent non-contact nature and high security, exhibiting tremendous potential in identity authentication and beyond. Nevertheless, challenges pertaining to the scarcity of training data and inconsistent image quality continue to impede the effectiveness of finger vein recognition (FVR) systems. To tackle these challenges, we introduce the visual feature-guided diamond convolutional network (dubbed 'VF-DCN'), a uniquely configured multi-scale and multi-orientation convolutional neural network. The VF-DCN showcases three pivotal innovations: Firstly, it meticulously tunes the convolutional kernels through multi-scale Log-Gabor filters. Secondly, it implements a distinctive diamond-shaped convolutional kernel architecture inspired by human visual perception. This design intelligently allocates more orientational filters to medium scales, which inherently carry richer information. In contrast, at extreme scales, the use of orientational filters is minimized to simulate the natural blurring of objects at extreme focal lengths. Thirdly, the network boasts a deliberate three-layer configuration and fully unsupervised training process, prioritizing simplicity and optimal performance. Extensive experiments are conducted on four FV databases, including MMCBNU_6000, FV_USM, HKPU, and ZSC_FV. The experimental results reveal that VF-DCN achieves remarkable improvement with equal error rates (EERs) of 0.17%, 0.19%, 2.11%, and 0.65%, respectively, and Accuracy Rates (ACC) of 100%, 99.97%, 98.92%, and 99.36%, respectively. These results indicate that, compared with some existing FVR approaches, the proposed VF-DCN not only achieves notable recognition accuracy but also shows fewer number of parameters and lower model complexity. Moreover, VF-DCN exhibits superior robustness across diverse FV databases.

Rigidity of the Delaunay triangulations of the plane

We prove a rigidity result for Delaunay triangulations of the plane under Luo's notion of discrete conformality, extending previous results on hexagonal triangulations. Our result is a discrete analogue of the conformal rigidity of the plane. We follow Zhengxu He's analytical approach in his work on the rigidity of disk patterns, and develop a discrete Schwarz lemma and a discrete Liouville theorem. As a key ingredient to prove the discrete Schwarz lemma, we establish a correspondence between the Euclidean discrete conformality and the hyperbolic discrete conformality, for geodesic embeddings of triangulations. Other major tools include conformal modulus, discrete extremal length, and maximum principles in discrete conformal geometry.

Multi-scale modeling of fog harvesting using thin-fiber grids – Towards new design rubrics

Fog collectors with fibers thinner than 1 mm harvest fog droplets more effectively at a low airflow velocity around 1 m s-1 than thicker fibers. However, existing models and design rubrics are restricted to thick fibers at higher velocity. This paper reports a multi-scale numerical model for fog harvesting at airflow velocity of 1 m s-1 using thin-fiber grids with different fiber spacing and diameter. The numerical model can simulate fog harvesting at two extreme length scales that are comparable to collector scale at the large end and fiber scale at the small end. The results confirm two new and important effects of fiber grid geometries on water collection efficiency, which are not included in existing theories and design rubrics. First, dense thin-fiber grids negatively influence the collection efficiency because of wall effect caused by viscous boundary layers. Second, the sparse thin-fiber grids can benefit from isolated clogging waterdrops and maintain relatively high efficiency when clogging blocks multiple grid openings. The two identified effects are then included to develop a new performance map for fog collectors, thereby shaping new design rubrics for fog harvesting. This work extends the existing theories of fog harvesting and sheds light on the design of novel fog collectors.

A Unified Multiscale Framework for Simulating Electrochemical Gas Evolving Reactions

The presence of gas bubbles in electrochemical systems, such as water-splitting, significantly increases overpotential and diminishes energy efficiency. High-fidelity simulation holds significant promise to gain mechanistic understanding of bubble dynamics and guide high-performance electrolytic cell design. However, the extreme length scales involved into electrochemical gas evolving systems, from sub-nanometer dictated by the electrical double layer (EDL) to a few centimeters featured by the electrolytic cell, have posed a huge challenge to enable sufficient numerical accuracy and superior computational efficiency. As a result, state-of-the-art numerical approaches either can only simulate a nanoscale computational domain or neglect the electrochemical kinetics within the EDL, impeding an in-depth understanding of how bubbles could intervene with the electrochemical process.In this work, we demonstrate a full-field simulation approach of electrochemical gas evolving reactions that can capture the electrochemical kinetics of the EDL in a centimeter-scale electrolytical cell with the presence of micro-to-millimeter scale bubbles. To resolve all characteristic length scales, the EDL is geometrically decoupled from the electrolytical cell but physically coupled with the bulk electrolyte and gas bubble through a quasi-1D treatment. As a result, the Nernst-Planck-Poisson-Boltzmann model can be rigorously solved in both the EDL and the rest of the electrolytical cell with highly affordable computational cost. Taking hydrogen evolution reaction as an example, we validated our approach by comparing with a variety of existing numerical and experimental results. For the first time, the impact of bubbles on the increase of overpotential observed in experiments can be quantitatively confirmed through numerical simulation. More notably, compared to state-of-the-art high-fidelity simulations, our approach exhibits a remarkable computational efficiency, which reduced the computational time by a factor of 100,000. This work provides a viable solution to simulate electrochemical gas evolving reactions with highly desirable numerical accuracy and unprecedented computational efficiency, which can serve as an effective tool to understand bubble dynamics and guide the design of next-generation electrolytical cells.

Flexible Hose Lining Applies in the Complex Site of Extreme Long Length and Numerous Bends

Flexible Hose Lining Applies in the Complex Site of Extreme Long Length and Numerous Bends

The role of reconstructive plastic surgery in the treatment of victims of the 2023 Kahramanmaraş earthquake

Objective: As a result of the 2023 Kahramanmaraş earthquake, medical institutions experienced a large influx of patients requiring acute multidisciplinary surgical and medical care. This study aimed to evaluate the patient demographics and treatment management of survivors admitted to our reconstructive plastic surgery department. Materials and Methods: We retrospectively analyzed the age, sex, time under the wreckage, time of admission, types and locations of injuries, treatment modalities, receipt of hyperbaric oxygen therapy, and receipt of vacuum-assisted closure therapy of the earthquake victims referred to our department. Results: The definitive management of all 42 earthquake survivors admitted to our department was reviewed. This included five free flaps, four regional flaps, 18 split-thickness skin grafts, and one maxillofacial fracture repair. Eight patients were treated conservatively including two with non-displaced maxillofacial fractures. Of the 26 patients treated for lower extremity injuries, four were already amputees. Among the remaining 22 patients with such injuries, one underwent Charcot amputation plus free flap reconstruction to preserve extremity length and one underwent below-the-knee amputation. Of the 16 upper extremity injuries, two patients referred with extensive forearm necrosis underwent forearm amputation. To preserve extremity length and ensure the limbs were suitable for biomechanical orthoses, free transverse upper gracilis musculocutaneous flaps and free chimeric Anterolateral- Vastus Lateralis musculocutaneous flaps were performed. Conclusion: This study illustrates the value of multi-modal reconstructive plastic surgery in the treatment of disaster survivors, particularly in the management of multi-trauma.

Obesity, Pocrescophobia and Oral Health.

Oral health plays a crucial role in obesity management. Scientific evidence suggests an association between obesity and oral diseases, including periodontal disease, dental caries, tooth erosion, xerostomia, and dentinal hypersensitivity. Maintaining optimal oral health is essential for obese patients, as compromised dentition or oral discomfort can influence dietary habits. However, managing oral health in obese individuals can be challenging due to anatomical limitations and lifestyle choices. Profound knowledge of obesity and its manifestations, the oral health professionals need to raise awareness and provide patients with comprehensive care. Pocrescophobia also known as obesophobia, is an intense fear of gaining weight. It affects both adoloscent women and men, manifesting as an irrational dread associated with weight gain. Like other phobias, obesophobia falls under the umbrella of anxiety disrders, leading to exaggerated anxiety when discussing or thinking about weight gain. Individuals with this fear may go to extreme lengths to avoid weight gain, which can increase the risk of developing eating disorders. Stress can lead to bruxism, wears away the occlusal surfaces and incisal edges, resulting in flat, shorter teeth. Smooth V-shaped cavities arise when lateral stresses surpass physiological limitations, resulting in gum recession and tooth discomfort. Canker sores, xerostomia, and lichen planus have all been linked to stress. By addressing both obesophobia and obesity as well as oral health, patients' overall well-being and quality of life can be improved.

Ophthalmology Residents' Experience in Cataract Surgery: Preoperative Risk Factors, Intraoperative Complications, and Surgical Outcomes.

This retrospective study explores the connection between preoperative patient risk factors, the experience of ophthalmology residents, and the outcomes of cataract surgeries performed at Hadassah Medical Center. It is hypothesized that with increased experience, residents may demonstrate greater proficiency in handling surgeries on higher-risk patients, potentially leading to improved surgical outcomes overall. Data were examined from 691 consecutive cataract surgeries in 590 patients, conducted by ophthalmology residents at Hadassah Medical Center (January 2018 to February 2022). Demographics, surgeon experience, preoperative cataract risk assessment score, and pre- and postoperative corrected distance visual acuity (CDVA) were analyzed. The risk score was based on cataract density, previous vitrectomy, presence of phacodonesis, small pupil, extreme axial length (> 30mm or < 21.5mm) or abnormal axial length (26-30mm), shallow anterior chamber (< 2.5mm), poor patient cooperation, oral alpha-1 blocker use, diabetic retinopathy (DR), Fuchs endothelial dystrophy, and having one functioning eye. This study focused on the correlation of risk scores with residents' surgical experience and surgical outcomes. As residents gained experience, surgeries on patients with at least one risk factor increased from 54% (first year) to 75% (second year; p < 0.001) and fluctuated between 75%, 82%, and 77% (third, fourth, and fifth years, respectively), with initial preoperative CDVA declining progressively. Despite handling more complex cases over time, the percentage of intraoperative complications per patient decreased with each year of residents' experience (17%, 13%, 11%, 17%, 6%; respectively). Patients without any risk factor had higher postoperative CDVA than those with one or more risk factors (mean ± standard deviation [SD] in logMAR, 0.16 ± 0.26 vs. 0.27 ± 0.35; p < 0.001) and a higher percentage of CDVA improvement (63% vs. 57%, p = 0.016). The use of a preoperative risk assessment scoring system to allocate surgeries to residents at varying experience levels may reduce the risk for surgical complications, thereby ensuring patient safety and providing residents with a gradual learning experience.

The effectiveness of controlled growth in correcting the inequality of the length of the lower extremities in the framework of multi-level simultaneous orthopedic interventions in children with hemiparetic forms of cerebral palsy

INTRODUCTION: Multilevel simultaneous orthopedic interventions in hemiparetic cerebral palsy imply correction of orthopedic complications on the involved limb and equalization or reduction of the inequality of the limb length. The effectiveness of correcting the inequality of limb length by controlled growth while improving the function of the involved limb by performing a multilevel orthopedic intervention remains unknown. AIM: To analyze the parameters of correction of the inequality of the length of the segments of the lower extremities using controlled growth in children with spastic hemiplegia in the framework of multilevel orthopedic interventions. MATERIALS AND METHODS: In 24 children with spastic hemiplegia, the results of correction of the inequality of the length of the lower extremities by controlled growth (extraphyseal epiphysiodesis) performed within the framework of multilevel simultaneous interventions were studied. RESULTS: The duration of correction was, on average, 18 months during hip surgery and 18.5 months with growth inhibition in the lower leg. Generally, considering the length of the segments of both the thigh and lower leg, the correction achieved was relatively satisfactory. Preoperatively, the difference in the total length of the thigh and lower leg was 18 mm (11–23), and after the correction period, it was 4 mm (−4.5–5.75). In performing epiphysiodesis before age 11 years, hypercorrection of the shortening of the involved limb may occur, considering the difference in the length of the thigh–shin segment. As age increases at the time of intervention (especially in the second half of puberty), the effectiveness of the controlled growth technique decreases. In all cases, when the correction value was 1 cm, patients’ age exceeded 144 months (12 years). CONCLUSION: Given the advantages of multilevel interventions in cerebral palsy, performing controlled growth within a single operation with reconstructive elements on the involved limb is preferable. The controlled and reversible nature of extraphyseal temporary epiphysiodesis is beneficial in achieving the required correction without high risks of excessive growth inhibition. Performing a controlled growth operation is preferable when the patient is ≤12–13 years old, considering the residual growth potential.

Orthopaedic complications of hemiparetic forms of cerebral palsy: problems of the lower extremities (literature review)

Introduction Spastic hemiplegia (a unilateral neurological disorder) is encountered more often in full-term infants. In most cases, the cause of the condition is intrauterine or perinatal stroke. Children with hemiparetic forms maintain cognitive and functional capabilities in combination with the ability to move independently. Among other forms of cerebral palsy, hemiparetic spastic forms range from 10.4 to 15.3 %. Types with mild motor impairments predominate according to the Gross Motor Function Classification System: 87.8 % are level I GMFCS, 7.1 % are level II GMFCS.The purpose of the work was to summarize information on the use of orthopaedic interventions for hemiparetic forms of cerebral palsy, both from the point of view of their planning and completeness of correction of anatomical disorders including lower limb length discrepancy, and assessment of functional results based on gait analysis.Materials and methods The search for publications was carried out in open electronic sources of medical literature PubMed, eLIBRARY, Scopus, Elsevier, Springer, Research Gate with a search depth of 20 years (2002–2022). The following inclusion criteria were used: systematic reviews of the literature, review articles, cohort studies on the topic of multilevel interventions for hemiparetic types of cerebral palsy.Results and discussion Lower limb length discrepancy of 1 cm or more affects the kinematics of the affected and intact contralateral limb. The unaffected limb is characterized by a compensatory flexion in the hip and knee joints and excessive dorsal flexion in the stance phase. On the affected side, the contribution of shortening to the development of pathological kinematics of the pelvis and spine is especially important. There is a high probability of equinus contracture after surgical correction due to unresolved discrepancy in the length of the lower extremities. Methods for correcting length discrepancy are conservative (compensation with shoes), and surgical lengthening of the lower leg, epiphyseodesis of the contralateral limb, shortening of the contralateral limb. There is no opinion in the literature about the preference of this or that method, and on the necessary magnitude of limb length correction.Conclusion The assessment of limb length discrepancy and contribution of this orthopaedic component to systemic movement disorders in spastic hemiparesis is based on computed tomography or magnetic resonance imaging, as well as on computer gait analysis. In the literature, the issue of limb length correction is considered separately from the complex of other orthopaedic interventions, while the features of correction with regard to spontaneous growth potential or after growth completion have not been defined. The advantage of equalizing the limb length in children with temporary epiphyseodesis over distraction osteogenesis is only supposed. There is not enough data on the effect of the limb length correction magnitude in patients with spastic hemiplegia on the parameters of computer gait analysis.

Lower Extremity Growth according to AI Automated Femorotibial Length Measurement on Slot-Scanning Radiographs in Pediatric Patients.

Background Commonly used pediatric lower extremity growth standards are based on small, dated data sets. Artificial intelligence (AI) enables creation of updated growth standards. Purpose To train an AI model using standing slot-scanning radiographs in a racially diverse data set of pediatric patients to measure lower extremity length and to compare expected growth curves derived using AI measurements to those of the conventional Anderson-Green method. Materials and Methods This retrospective study included pediatric patients aged 0-21 years who underwent at least two slot-scanning radiographs in routine clinical care between August 2015 and February 2022. A Mask Region-based Convolutional Neural Network was trained to segment the femur and tibia on radiographs and measure total leg, femoral, and tibial length; accuracy was assessed with mean absolute error. AI measurements were used to create quantile polynomial regression femoral and tibial growth curves, which were compared with the growth curves of the Anderson-Green method for coverage based on the central 90% of the estimated growth distribution. Results In total, 1874 examinations in 523 patients (mean age, 12.7 years ± 2.8 [SD]; 349 female patients) were included; 40% of patients self-identified as White and not Hispanic or Latino, and the remaining 60% self-identified as belonging to a different racial or ethnic group. The AI measurement training, validation, and internal test sets included 114, 25, and 64 examinations, respectively. The mean absolute errors of AI measurements of the femur, tibia, and lower extremity in the test data set were 0.25, 0.27, and 0.33 cm, respectively. All 1874 examinations were used to generate growth curves. AI growth curves more accurately represented lower extremity growth in an external test set (n = 154 examinations) than the Anderson-Green method (90% coverage probability: 86.7% [95% CI: 82.9, 90.5] for AI model vs 73.4% [95% CI: 68.4, 78.3] for Anderson-Green method; χ2 test, P < .001). Conclusion Lower extremity growth curves derived from AI measurements on standing slot-scanning radiographs from a diverse pediatric data set enabled more accurate prediction of pediatric growth. © RSNA, 2024 Supplemental material is available for this article.

Ultrasound Duplex Scanning of Vessels in the Diagnosis of Limb Length Discrepancy in Pediatric Patients with Congenital Vascular Malformations

Ultrasound Duplex Scanning of Vessels in the Diagnosis of Limb Length Discrepancy in Pediatric Patients with Congenital Vascular Malformations

Optimizing calibration of modern skeletal maturity systems.

Greulich and Pyle is the most used system to estimate skeletal maturity but has significant drawbacks, prompting the development of newer skeletal maturity systems, such as the modified Fels skeletal maturity systems based on knee radiographs. To create a new skeletal maturity system, an outcome variable, termed a "skeletal maturity standard," must be selected for calibration of the system. Peak height velocity and 90% of final height are both considered reasonable skeletal maturity standards for skeletal maturity system development. We sought to answer two questions: (1) Does a skeletal maturity system developed using 90% of final height estimate skeletal age as well as it would if it was instead developed using peak height velocity? (2) Does a skeletal maturity system developed using 90% of final height perform as well in lower extremity length prediction as it would if it was instead developed using peak height velocity? The modified Fels knee skeletal maturity system was recalibrated based on 90% of final height and peak height velocity skeletal maturity standards. These models were applied to 133 serially obtained, peripubertal antero-posterior knee radiographs collected from 38 subjects. Each model was used to estimate the skeletal age of each radiograph. Skeletal age estimates were also used to predict each patient's ultimate femoral and tibial length using the White-Menelaus method. The skeletal maturity system calibrated with 90% of final height produced more accurate skeletal age estimates than the same skeletal maturity system calibrated with peak height velocity (p < 0.05). The 90% of final height and peak height velocity models made similar femoral and tibial length predictions (p > 0.05). Using the 90% of final height skeletal maturity standard allows for simpler skeletal maturity system development than peak height velocity with potentially more accuracy.