Objective To investigate the changes in the position of the fibular sesamoid bone with hallux valgus aggravated under two conditions:the foot bearing anteroposterior radiography(reflecting the static bearing state of the foot)and the sesamoid bone bearing axial radiography(reflecting the foot movement state).Methods Seventy-four feet with clinically suspected hallux valgus were finally enrolled in 49 feet,including 14 in the mild group,23 in the moderate group,and 12 in the severe group.Three indica-tors were measured on anteroposterior and axial radiographs:the position of the fibular sesamoid bone in anteroposterior radiographs(SP)and sesamoid axial position(SAP),and the rotation angle of the fibular sesamoid articular surface(RAf).The vertical distance between the fibular sesamoid bone and the second metatarsal bone was used to represent the position of the fibular sesamoid bone,then the position of the fibular sesamoid in the anteroposterior and axial positions was specifically marked as SPf-2 and SAPf-2.To cor-rect the anatomical differences of each foot,the ratio of the measured distance index to the length of the second metatarsal bone(AB),namely SPf-2/AB,SAPf-2/AB,was included in the statistical analysis.Results SPf-2/AB and SAPf-2/AB had no significant difference between hallux valgus groups(P＞0.05).The mean values of SPf-2/AB and SAPf-2/AB were significantly different(P＜0.05).RAf was positively correlated with hallux valgus angle(HVA)(r=0.725,P＜0.001),increased as HVA increased.Conclusion Both weight-bearing anteroposterior and sesamoid axial radiographs(foot at rest and in motion),the position of the fibular sesamoid bone is not affected by hallux valgus,and the distance from the center of the fibular sesamoid bone to the second metatarsal bone remains unchanged.The position of the fibular sesamoid bone is not the same between the anteroposterior and axial radiographs,so it is necessary to evaluate the position of the fibular sesamoid bone in the two states respectively and combine the two methods.RAf increases with the increase of HVA in axial view,it is considered that although the central position of the fibular sesamoid bone remains the same under foot movement,it does reverse spin movement toward the tibial side with the aggravation of hallux valgus.