Volumetric relationships of foot bones and the role of the talus in hallux valgus
Yakup Ekinci1
, Ahmet Payas2, Ahmet Yesevi Sarıaslan1, Zeliha Kaya Erten3, Feridun Arat1, Sabri Batın1
1Department of Orthopedics and Traumatology, University of Health Sciences, Kayseri City Training and Research Hospital, Kayseri, Türkiye
2Department of Anatomy, Amasya University, Faculty of Medicine, Amasya, Türkiye
3Department of Nursing, Nuh Naci Yazgan University, Health Sciences Faculty, Kayseri, Türkiye
Keywords: Computed tomography, hallux valgus, talus, tarsal bones, three-dimensional imaging, volume measurement.
Abstract
Objectives: This study aims to evaluate the foot as a whole, to compare the foot bones in terms of volume, and investigate the role of the foot bones in the formation of hallux valgus (HV).
Patients and methods: Between February 2024 and September 2024, a total of 21 patients (6 males, 15 females; mean age: 29.04 ± 5.21 years; range, 19 to 38 years) with an HVA of ≥30° and intermetatarsal angle (IMA) of ≥ 13° were included in this prospective study. The control group consisted of 18 patients (5 males, 13 females; mean age: 28.94 ± 5.56 years; range, 20 to 39 years) with an HVA of <15°. Computed tomography (CT) images were uploaded to the 3D Slicer program, and the volumes of the foot bones were measured and calculated as percentages.
Results: In terms of volume percentage, the mean talus (22.68 ± 1.62 vs. 21.37 ± 1.81; d = 0.78; 95% CI 0.10–1.44) and the fifth metatarsal (4.63 ± 0.85 vs. 4.15 ± 0.52; d = 0.65; 95% CI -0.01–1.29) were higher, while the mean cuboid volume (5.31 ± 0.71 vs. 5.89 ± 0.55; d = 0.90; 95% CI 0.23–1.57) was lower in the HV group, indicating a statistically significant difference (p<0.05). No significant difference was observed in the volume ratios between the bones of the medial and lateral rays (p ≥ 0.05). When medial ray bones were combined, the ratios of talus/medial cuneiform (d = 0.92) and (talus + 1st metatarsal)/medial cuneiform (d = 0.82; 95% CI 0.20–1.52) were found to be significantly higher in the HV group (p < 0.05).
Conclusion: Although genetic factors are widely considered to play a key role in HV development, we propose that the process originates more proximally, most likely at the level of the talus. Based on our study results, we conclude that an increase in talar volume may lead to a compensatory reduction in the volumes of the cuboid and medial cuneiform bones, initiating a sequence in which soft-tissue forces contribute to progressive pronation of the first metatarsal, ultimately resulting in HV.
Citation: Ekinci Y, Payas A, Sarıaslan AY, Kaya Erten Z, Arat F, Batın S. Volumetric relationships of foot bones and the role of the talus in hallux valgus. Jt Dis Relat Surg 2026;37(x):i-ix. doi: 10.52312/ jdrs.2026.2537.