Role of Ultrasound in Determining the Severity of Hallux Valgus: Ultrasonic Characteristics of Abductor Hallucis Muscle

Mohammad Bagheri Bidhendy,Elham Neshan

doi:10.31661/gmj.v4i4.527

Mohammad Bagheri Bidhendy, Elham Neshan

Open Access

https://doi.org/10.31661/gmj.v4i4.527

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Abstract

H Valgus is a forefoot deformity involving progressive lateral deviation of the hallux and medial deviation of the first metatarsal resulting in a medial prominence at the first metatarsophalangeal joint [1]. Such a deformity is more common in older population with estimated prevalence of 36% in those over 65, while the prevalence rate in adults between 18 and 65 years is 23% [2]. Although the deformity may remain asymptomatic, it has been associated with cosmetic appearance concerns, pain and reduced health-related quality of life [3]. Previous studies introduced some risk factors, which involve hallux valgus including increasing age, being female, a positive family history of hallux valgus, abnormal hind foot kinematics, wearing high heels or tight footwear [4-6]. Bony abnormalities (roundshaped first metatarsal head, long first metatarsal, bipartite medial sesamoids) and muscular abnormalities (accessory extensor hallucis longus tendon and accessory tibialis posterior tendon) have also been linked to the deformity [7-9]. Despite the involvement of abductor hallucis muscle in the pathomechanics of this deformity, a limited number of studies have investigated the abductor hallucis muscle with hallux valgus [4]. Although studies indicated that the computed tomography and magnetic resonance imaging as well as EMG are the choice tools in the evaluation of musculoskeletal disorders [9], evidence has also shown that ultrasound proves similar validity to EMG and manual muscle testing in assessing neuromuscular pathologies in extrinsic and intrinsic foot muscles with an added advantage in its ability to visualize muscle atrophy [10]. Hence, the aim of this study is to employ musculoskeletal ultrasound to determine significant differences between dorsoplantar (DP) thickness, medio-lateral (ML) width and cross-sectional area (CSA) of the abductor hallucis muscle among different severities of hallux valgus. This cross-sectional study was performed on 50 participants aged over 20 years attending Boo-Ali hospital in Tehran, Iran from April 2014 to April 2015. The study was approved by the ethical committee of Azad University and written informed consent for participation was obtained. Exclusion criteria included history of foot or ankle surgery, current trauma to the foot and ankle, a neuromuscular condition or a diagnosis of inflammatory arthritis or diabetes mellitus. Hallux valgus was measured using Manchester Scale which utilizes four photographs of increasing severity of hallux valgus (Figure1). This tool has been shown to have excellent reliability and validity in both clinical assessment and self-assessment of hallux valgus [2]. The scale is graded 0 for no deformity, 1 for mild deformity, 2 for moder-

Highlights

Sonograghy and Hallux Valgus ate deformity and 3 for severe deformity [2]
The researcher observed each participant in relaxed weight-bearing stance to determine which one of the four Manchester Scale photographs best represented the degree of hallux valgus deformity
The ultrasound machine has been shown to produce reliable images of the abductor hallucis muscle for the purpose of measuring ML width,DP thickness and CSA [1].A similar procedure to that outlined by Stewart[1]was used by the researcher to obtain ultrasound images in the current study

Summary

Introduction

The researcher observed each participant in relaxed weight-bearing stance to determine which one of the four Manchester Scale photographs best represented the degree of hallux valgus deformity. ALOKA SSD 3500 Ultrasound System (Tokyo, Japan) with a 50 mm linear probe of 7.5 MHz was used to obtain images of the abductor hallucis muscle belly. The ultrasound machine has been shown to produce reliable images of the abductor hallucis muscle for the purpose of measuring ML width,DP thickness and CSA [1].A similar procedure to that outlined by Stewart[1]was used by the researcher to obtain ultrasound images in the current study. The foot to be measured was positioned with the ankle at neutral(i.e. 0°).

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