Accuracy of magnetic resonance imaging for diagnosing hallux valgus.

Paulo Victor Partezani Helito,Marcelo Bordalo Rodrigues,Stephano Raydan Ramalho Rocha,Claudia Da Costa Leite,Rafael Trevisan Ortiz,Giovanni Guido Cerri

doi:10.1590/0100-3984.2019.0054

Paulo Victor Partezani Helito, Marcelo Bordalo Rodrigues + Show 4 more

Open Access

https://doi.org/10.1590/0100-3984.2019.0054

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Abstract

ObjectiveTo assess the accuracy of magnetic resonance imaging (MRI) for the diagnosis of hallux valgus using radiography during weight bearing as the gold standard.Materials and MethodsThis was a retrospective analysis of all patients undergoing MRI of the foot and radiography of the foot during weight bearing at our institution between January and June of 2015. The hallux valgus angle (HVA) was measured on MRI and radiography. The Wilcoxon signed-rank test and simple linear regression were used in order to compare measurements. Patients were divided into two groups according to the HVA determined on radiography: > 15° (hallux valgus) and ≤ 15° (control). Qualitative and quantitative assessments of MRI scans were performed. For quantitative assessment, receiver operating characteristic curves were used in order to determine the HVA cutoff with the highest accuracy.ResultsA total of 66 MRI scans were included, 22 in the hallux valgus group and 44 in the control group. Wilcoxon signed-rank tests indicated a significant difference between the radiography and MRI measurements. Simple linear regression showed a nonlinear relationship between the measurements and values did not present a strong correlation. In comparison with the radiography measurements, MRI with an HVA cutoff of 16.4° exhibited the highest accuracy (86%). The accuracy of the subjective (qualitative) assessment was inferior to the objective assessment (measurement of the HVA).ConclusionHallux valgus can be diagnosed by measuring the HVA on MRI, satisfactory accuracy being achieved with an HVA cutoff of 16.4°.

Highlights

Hallux valgus is one of the most common afflictions of the foot, potentially causing pain and significant deformity[1,2,3]
Hallux valgus can be diagnosed by measuring the hallux valgus angle (HVA) on magnetic resonance imaging (MRI), satisfactory accuracy being achieved with an HVA cutoff of 16.4°
We evaluated 67 MRI scans of the foot accompanied by plain radiographs obtained within the preceding six months, corresponding to a total of 52 patients

Summary

Introduction

Hallux valgus is one of the most common afflictions of the foot, potentially causing pain and significant deformity[1,2,3]. The condition has a multifactorial, controversial etiology and is often associated with the use of inappropriate shoes, predisposing anatomy, and occupational risks, as well as genetic factors[1,2,3,4]. The higher prevalence among women is attributable to predisposing anatomy and the use of inappropriate shoes[1,3,4,5]. Several radiological parameters analyzed on radiography of the foot during weight bearing can be used to facilitate the diagnosis. Notable among such parameters is the hallux-metatarsophalangeal angle, or hallux valgus angle (HVA), which is defined as the angle formed by the intersection of the longitudinal axis of the first metatarsal bone diaphysis and the first proximal phalanx. Studies employing the gold standard (radiography of the foot during weight bearing) have established that HVA values ≤ 15° are normal[5,6,7,8,9]

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