The Correlation between Hallux Valgus Angle and Radiological Indices in Patients with Hallux Valgus

Accurate diagnosis of bone structure and disease severity in patients with hallux valgus is crucial. Therefore, this study aims to investigate the correlation between the hallux valgus angle and other radiological angles and indices in patients with hallux valgus deformity.

This cross-sectional analytical study was conducted from 2021 to 2022. The study population consisted of patients with hallux valgus deformity. First, basic demographic information of participants was documented, then, a standing dorsoplantar foot radiograph was performed for all patients. Radiological information of the patients, including hallux valgus angle, the first-second intermetatarsal angle, the first-fifth metatarsal angle, the first metatarsal length, the ratio of the length of the first metatarsal to the second, and the horizontal distance between the distal of the first and fifth metatarsals were measured. In addition, to evaluate the clinical severity of hallux valgus, macroscopic photographs were taken from the patients in the same position using a digital camera. Four expert physicians evaluated the photographs separately and blindly based on the visual analogue scale (VAS) index. The VAS score ranged from 0 to 10, with 0 representing the minimum disease severity and 10 representing the maximum deformity in hallux valgus. The relationship between variables was investigated using Pearson's correlation coefficient and a linear regression model.

In this study, 110 patients (94 females and 16 males) were enrolled, of which 80 patients (72.8%) had a moderate hallux valgus, and 30 patients (27.3%) had severe hallux valgus based on the clinical severity of hallux valgus (VAS). The results of the Pearson correlation and linear regression model showed that the hallux valgus angle had the highest positive correlation with the first-fifth metatarsal angle (correlation coefficient of 0.55 and P < 0.001), the first-second intermetatarsal angle (correlation coefficient of 0.52 and P < 0.001), and the ratio of the length of the first metatarsal to the second (correlation coefficient of 0.24 and P = 0.01).

The results of this study revealed that some radiological indices correlate with the hallux valgus angle and, consequently, the disease severity. These findings highlight the importance of considering these factors in patients' radiographs and during corrective surgeries.