Calf valgus is exactly knee valgus, including unilateral calf valgus and bilateral calf valgus, as follows: 1. Unilateral calf valgus: the knee joint is mostly K-shaped. 2. Bilateral calf valgus: the knee joint is X-shaped, i.e., when both knees are together, the ankle joints on both sides are far apart. In the occurrence of knee valgus, patients are often accompanied by narrowing of the lateral space, which over time will lead to cartilage wear of the lateral space and osteoarthritis of the lateral space, which may cause chronic pain in the knee joint. Calf valgus is usually treated orthopedically in adults or in the elderly, and if it has caused significant degenerative arthritis, total knee replacement surgery is usually performed.