Pelvis radiographs in children with cerebral palsy: effects of patient positioning on calculating migration percentages.

TitlePelvis radiographs in children with cerebral palsy: effects of patient positioning on calculating migration percentages.
Publication TypeJournal Article
Year of Publication2023
AuthorsJarrett DY, Stamoulis C, Shore BJ, Tsai A
JournalPediatr Radiol
Volume53
Issue13
Pagination2662-2671
Date Published2023 Dec
ISSN1432-1998
KeywordsAdolescent, Cerebral Palsy, Child, Hip Dislocation, Humans, Kyphosis, Lordosis, Male, Patient Positioning, Pelvis, Radiography, Reproducibility of Results
Abstract

BACKGROUND: Hip displacement in children with cerebral palsy (CP) is monitored by measuring migration percentage on anteroposterior pelvis radiographs. However, proper positioning for radiography in children with spasticity is difficult. The reliability and accuracy of migration percentage as a function of patient positioning is unknown.

OBJECTIVE: To determine the effects of patient positioning on migration percentage measurements in children with CP.

MATERIALS AND METHODS: We identified children with CP (≤18-year-old) with pelvis CT and anteroposterior pelvis radiograph obtained <6 months apart (10/2018-11/2021). Digitally reconstructed radiographs were generated from each pelvis CT, to simulate nine different patient positions: neutral; 10° and 20° lordosis and kyphosis; and 10° and 20° right rotation and left rotation. Two radiologists measured migration percentages from the simulated and real pelvis radiographs. We used Spearman's rho to assess inter-rater reliability, and Wilcoxon signed rank test to determine statistical significance.

RESULTS: We studied sixty-three children (male=41; median age=8 years; range=4-18 years). The two radiologists' migration percentage measurements were highly correlated with each other across all simulated and real radiographs (Spearman's rho=0.86-0.99, P<0.01). For both readers and hips, migration percentages measured from real radiographs were significantly different from those measured from neutral simulated radiographs (P<0.01), with median absolute difference=5-6 percentage points (PP) and interquartile range (IQR)=9-12 PP. When comparing migration percentage measurements from neutral simulated radiographs to those in kyphosis/lordosis and right/left rotations, median absolute differences were 2-4 PP (IQR=3-8 PP) and 4-15 PP (IQR=6-17 PP), respectively.

CONCLUSION: Inter-rater reliability of measured migration percentages is high, but accuracy decreases with patient positional changes.

DOI10.1007/s00247-023-05783-7
Alternate JournalPediatr Radiol
PubMed ID37833504
PubMed Central ID5351288

Weill Cornell Medicine
Department of Radiology
525 East 68th Street New York, NY 10065