Influence of investigator experience on reliability of adult acquired flatfoot deformity measurements using weightbearing computed tomography

•AAFD measurements with WBCT are reliable regardless of investigator experience.•We found overall substantial to perfect intra- and interobserver reliability.•Similar results for medical student, orthopedic resident, and orthopedic surgeon. Our purpose was to assess the reliability of measurements of adult-acquired flatfoot deformity (AAFD) taken by investigators of different levels of clinical experience using weightbearing computed tomography (WBCT). Nineteen AAFD patients underwent WBCT. Three investigators with different levels of clinical experience made AAFD measurements in axial, coronal, and sagittal planes. Intra- and interobserver reliability were assessed. Mean values for each measurement were compared between investigators. After a training protocol, substantial to perfect intra- and interobserver reliability was observed for most measures, regardless of the investigator’s experience level. Significant differences between investigators were observed in 2 of 21 measured parameters: medial cuneiform–first metatarsal angle (P=0.003) and navicular–medial cuneiform angle (P=0.001). AAFD radiographic measurements can be performed reliably by investigators with different levels of clinical experience using WBCT. Level II, prospective comparative study.