Chemotherapy is a common treatment for ovarian cancer, if knee pain occurs after chemotherapy, it is generally considered to be toxic side effects of chemotherapy, such as synovitis or knee joint degeneration. 1. Synovitis: chemotherapy for ovarian cancer will stimulate the synovial membrane inside the knee joint, which will cause synovitis, resulting in swelling of the knee joint, which may cause knee pain. 2. Joint degeneration: chemotherapy may lead to degeneration of knee joint, ischemia of cartilage bone inside the joint, which may cause cartilage degeneration, damage, breakage, or even necrosis of bone, which may also lead to knee joint pain. If knee joint pain occurs in the course of chemotherapy for ovarian cancer, symptomatic treatment can be tried, and if it cannot be relieved and gradually aggravated, one should consult a doctor in time.