Radiological characteristics of hallux valgus with metatarsus adductus: A matched case-control study

No evidence has been found to support the hypothesis that there is a correlation between hallux valgus (HV) and intermetatarsal (IM) angles in HV with metatarsus adductus (MA) and that IM angle in HV with MA is lower than that in HV without MA. The present study aimed to analyze the radiographic characteristics of HV with MA compared to matched controls and to clarify the differences between HV with MA and without MA.

Preoperative radiographs of 126 female patients (164 feet) who underwent hallux valgus surgery were reviewed. The HV, IM, and MA angles were measured. The MA was defined as MA angle of 20° or greater. Of all the feet, 37 (22.6%) had HV with MA (MA group). Control A (111 feet) having HV without MA was matched by age, gender, and BMI to MA group; Control B (79 feet) having HV without MA was matched by age, gender, BMI, and HV angle to the sub-MA group (31 feet) having HV with MA.

The correlation coefficient between the HV and IM angles in the MA group was considered negligible (r = 0.08, p = 0.63), whereas the correlation coefficient in Control A was considered moderate (r = 0.57, p < 0.00001). The correlation coefficient in the MA group was significantly smaller than in Control A (p < 0.01). There was no significant difference in the HV angle between the sub-MA group and Control B (p = 0.23), but the IM angle was significantly smaller than in Control B (p = 0.002).

There is no significant correlation between the HV and IM angles in HV with MA, as there is in HV without MA. HV with MA has a significantly smaller IM angle for the HV angle compared to HV without MA.