Genu valgum is a common deformity in untreated rheumatoid arthritis. While most often it occurs in both knees bringing them together, genu varum (bow leg) can also occur. This slide illustrates a woman with severe rheumatoid arthritis who has both a genu valgum of the right knee and a genu varum of the left knee. This is sometimes referred to as the ""windswept"" deformity. The added stress this knee disability imposes on the feet and ankles, the hips, and the spine should also be noted.