Validity and Reliability of a New Radiological Method to Estimate Medial Column Internal Rotation in Hallux Valgus Using Foot Weight-Bearing X-Ray

Background Medial column internal rotation in hallux valgus (HV) can be measured using weight-bearing computed tomography (WBCT). Anteroposterior weight-bearing foot radiographs' (WBXR) ability to estimate medial column internal rotation in HV was evaluated comparing these measurements with those obtained from WBCT.Methods Three observers evaluated WBCT and WBXR of 33 HV feet twice. Medial column internal rotation was measured with WBCT and classified into 3 levels according to WBXR findings. Intra- and interobserver reliability were obtained for WBXR and WBCT, in addition to WBXR-WBCT correlation.Results WBXR and WBCT intraobserver agreement was substantial and near perfect, respectively (kappa 0.79 and 0.84). Their interobserver agreement was excellent (intraclass correlation 0.85 and 0.9, respectively). The WBXR-WBCT correlation was substantial (kappa 0.68). WBXR diagnostic accuracy to predict the WBCT results was 85%.Conclusions The proposed method for medial column internal rotation measurement using WBXR is reliable and has a substantial agreement with WBCT measurements.Levels of Evidence Level III