TITLE:
A Method for Measurement of the Hypertrophic First Metatarsal Medial Eminence on Foot Radiographs—A Reliability Study with Surgical Implications
AUTHORS:
Paul S. Armanasco, Kathy Briffa, Nick Pang
KEYWORDS:
Hallux Valgus; Medial Eminence; Radiograph; Surgery; Reliability
JOURNAL NAME:
Journal of Analytical Sciences, Methods and Instrumentation,
Vol.4 No.1,
March
26,
2014
ABSTRACT: Background: It has been suggested that hypertrophic eminence on the medial head of the
first metatarsal is a component of the patho-anatomy of hallux valgus. However,
research findings in this area are inconsistent, possibly due to differences in
methods in identifying and measuring the medial eminence. To date, reliability
of any method of measurement has not been reported. The purpose of this study
was to determine the reliability of measurement of the medial eminence on
medial oblique and dorsoplantar radiographs using a
previously described geometric technique. Methods: To evaluate the reliability of a method of measurement of the medial eminence
of the first metatarsal duplicate standardized dorsoplantar and medial oblique
radiographs were taken of one foot of 15 subjects. The feet included both
rectus feet and subjects with hallux valgus. The medial eminence was measured
on the digital images using Inteleviewer 2.5 (Intelerad medical systems
incorporated, Montreal, Quebec) software. Observer 1 measured one randomly
selected image from each subject to determine inter-observer reliability.
Observer 2 measured all images to determine the overall intraobserver
reliability. Reliability was calculated using intra-class correlation
coefficients (ICC). Results: The mean projection
of the medial eminence ranged from 0.39 to 0.44 cm in both views. The ICCs were
calculated for the dorsoplantar view and the 2 medial oblique view measures
between observers. They ranged from 0.76 intra-rater and 0.86 interrater in the
dorsoplantar view to 0.80 intra-rater and 0.90 inter-rater in the medial
oblique view indicating good reliability in all measures. The average of the 4
oblique views also showed a high level of reliability with a coefficient of
0.96. Conclusions: The medial eminence
can be reliably measured in the medial oblique and dorsoplantar view using the
described technique. The medial oblique and the dorsoplantar views are valuable
and reliable projections for visualising the dorso medial aspect of the first
metatarsal.