Patients with calf valgus are commonly caused by congenital or secondary factors, as follows: 1. congenital factors: mainly seen in pediatric patients, patients may show bilateral calf valgus. 2. secondary factors: such as rickets, osteodystrophy, abnormal bone development, rheumatoid arthritis, epiphyseal injury, tibial plateau fracture, and thinning of the lateral cartilage of the joint, such as osteoarthritis, and medial ligament elongation such as neuroarthropathy, paralytic deformity, and hip inversion ankylosis. Patients will present with knee valgus, and unilateral patients are prone to limp, while bilateral patients will have a wobbly gait, which can be combined with flatfoot and patellar dislocation, etc. Patients will have knee pain and limited movement.