An Assessment of Knee Flexion in Lateral Knee X-rays

Purpose: Patient positioning plays a crucial role in the field of radiology. Lateral knee x-rays are a type of image that often has incorrect positioning of the angle of knee flexion. The ideal range is between 20-30 degrees. The goal of this study was to assess the angle of knee flexion at two different locations in a single hospital system while determining if several variables influence the angle.

Methods: This study is a retrospective chart review that assessed the angle of knee flexion in patients 18 years or older that underwent a lateral-mediolateral knee x-ray taken at an urgent care center and a general diagnostic center of a hospital within the same system between March 1 and December 1, 2021. Variables including age, sex, BMI, technologist, and location were collected from these patients’ charts and evaluated. MRI information was gathered for patients who underwent an MRI within 30 days of a lateral knee x-ray. The research team assessed effusions reported on x-ray compared to effusions reported on MRI for these patients.

Results: Among patients included in the study (n=665) the average angle of knee flexion was 51.28 degrees. Age, sex, BMI, and location were not significantly associated with the mean angle of knee flexion with p-values of 0.63, 0.13, 0.55, and 0.15 respectively. The radiology technologist taking the image did have an association with the angle of knee flexion with a p- value of 0.001. Differences in the mean angle of knee flexion between the groups of x-rays with effusions reported compared to the groups of x-rays where effusions were not reported but found on MRI resulted in a p-value of 0.83.

Conclusions: The technologist taking the image was the only variable of this study that had a significant difference in mean angle of knee flexion. Additional studies are needed to determine what technologist factors are most important in determining the angle of knee flexion. Using MRI information to evaluate if effusions were not reported due to the angle of knee flexion was limited in this study due to small sample size.

Etiology and Clinical Features of Optic Neuritis in Two Children: A Case Report

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Background: Optic neuritis (ON) is inflammation of the optic nerve that can occur in both adults and children. This disease is marked by a heterogeneous presentation in children and has clinical and epidemiologic characteristics that differ greatly from those found in adults. The purpose of this report is to illustrate the clinical features of ON that occur during childhood and to highlight the differences of ON in children versus adults. In doing so, we aim to add to the sparse current literature on this topic and help prevent the future misdiagnosis of ON in pediatric patients.

Case Presentations: An 11-year-old female presented with bilateral decreased visual acuity and significant ocular pain. The ophthalmic presentation and diagnostic workup led to the diagnosis of acute disseminated encephalomyelitis with ON. A second patient, a 12-year-old male, presented with decreased visual acuity and bilateral papilledema. Alongside a diagnosis of bilateral ON, a muscle biopsy confirmed mitochondrial cytopathy as the etiology of his presenting symptoms.

Conclusions: ON in children may be related to specific infections, autoimmune disorders, diseases of adjacent anatomical structures, or demyelinating disorders. Attacks may be acute or subacute with signs of reduced visual acuity, abnormal pupillary response, loss of color vision, impaired contrast sensitivity, and decreased peripheral vision. Awareness of this complex disease allows the clinician to initiate specific treatment and follow-up care that may reduce subsequent morbidity and the rate of recurrence.