Improving the quantitative classification of Erlenmeyer flask deformities

Adusumilli, Gautam, Kaggie, Joshua D., D’Amore, Simona, Cox, Timothy M., Deegan, Patrick, MacKay, James W. ORCID: and McDonald, Scott and GAUCHERITE Consortium (2021) Improving the quantitative classification of Erlenmeyer flask deformities. Skeletal Radiology, 50 (2). 361–369. ISSN 0364-2348

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The Erlenmeyer flask deformity is a common skeletal modeling deformity, but current classification systems are binary and may restrict its utility as a predictor of associated skeletal conditions. A quantifiable 3-point system of severity classification could improve its predictive potential in disease. Ratios were derived from volumes of regions of interests drawn in 50 Gaucher’s disease patients. ROIs were drawn from the distal physis to 2 cm proximal, 2 cm to 4 cm, and 4 cm to 6 cm. Width was also measured at each of these boundaries. Two readers rated these 100 femurs using a 3-point scale of severity classification. Weighted kappa indicated reliability and one-way analysis of variance characterized ratio differences across the severity scale. Accuracy analyses allowed determination of clinical cutoffs for each ratio. Pearson’s correlations assessed the associations of volume and width with a shape-based concavity metric of the femur. The volume ratio incorporating the metaphyseal region from 0 to 2 cm and the diametaphyseal region at 4–6 cm was most accurate at distinguishing femurs on the 3-point scale. Receiver operating characteristic curves for this ratio indicated areas of 0.95 to distinguish normal and mild femurs and 0.93 to distinguish mild and severe femurs. Volume was moderately associated with the degree of femur concavity. The proposed volume ratio method is an objective, proficient method at distinguishing severities of the Erlenmeyer flask deformity with the potential for automation. This may have application across diseases associated with the deformity and deficient osteoclast-mediated modeling of growing bone.

Item Type: Article
Uncontrolled Keywords: clinical cutoffs,distal femur,erlenmeyer flask deformity,mri,shape analysis,sphericity,surface area,radiology nuclear medicine and imaging ,/dk/atira/pure/subjectarea/asjc/2700/2741
Faculty \ School: Faculty of Medicine and Health Sciences > Norwich Medical School
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Depositing User: LivePure Connector
Date Deposited: 02 Sep 2020 23:54
Last Modified: 03 Nov 2022 16:31
DOI: 10.1007/s00256-020-03561-2


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