Pain in front of the knee is commonly caused by prepatellar bursitis, patellar fracture, etc., as follows: a. Prepatellar bursitis: bursa exists within the subcutaneous tissue in front of the patella, which can reduce local wear and tear, and patients who maintain a prolonged kneeling posture for work or exercise can lead to acute or chronic inflammation of the prepatellar bursa, and patients will have pain and swelling in front of the knee, and knee joint activities will be affected, and painful symptoms are aggravated when touched, and local The patient will have pain and swelling in the anterior aspect of the knee. The diagnosis can be confirmed by ultrasound examination, and the symptoms will be relieved by physical therapy, rest and braking. Patellofemoral fracture: direct impact injury to the knee joint can lead to patellofemoral fracture, and in severe cases, comminuted fracture can occur, and the patient will have pain in front of the knee joint, limited movement, and local swelling.