Habitual patellar dislocation is mostly seen in young adolescents, mostly unilateral lesions, bilateral onset is not uncommon, the main symptom is that when the knee joint is flexed, the patella is displaced laterally, when the knee joint is straightened, the dislocated patella can be reset by itself, or gently pushed back with manipulation, then the patient can straighten the joint and lift the affected limb. X-rays show flattening of the femoral epicondyle with varying degrees of traumatic changes and a smaller than normal patella. Habitual patellar dislocation should be treated surgically, and according to its pathological changes, one or several surgical treatments are used, mainly: 1. anterior displacement of the medial femoral muscle to the patella 2. inferior displacement of the tibial tuberosity patellar tendon attachment 3. elevation of the femoral epicondyle 4. knee valgus osteotomy orthopedic surgery.