Anatomical Variations

The Japanese population has bony anatomical variations that are rare in Western populations, mainly in the coronal plane, [1–3] and anatomical variations common with Western populations, mainly in the sagittal plane [4, 5]. In this section, we summarize the contents of each variation, the evaluation method, and the relationship between each osseous variation commonly seen in knees with medial osteoarthritis. Please refer to another article on lateral-type arthropathy [6].