Total knee replacement with combined patellar dislocation is a relatively rare and challenging procedure, and only a few cases have been reported both nationally and internationally. We report on the surgical technique of total knee replacement with complete patellar dislocation. Patients with severe knee osteoarthritis combined with patellar dislocation often present with the following anatomic abnormalities: 1. tibiofemoral joint valgus and external rotation 2. medial soft tissue laxity and abnormal VMO development 3. increased Q angle 4. tension in the lateral support band 5. patellar elevation, severe patellar deformity (concavity), patellar enlargement 6. complex lower extremity torsion, femoral anteversion 7. quadriceps shortening The anatomic abnormalities of patellar dislocation determine the choice of surgical procedure. The patient often has multiple abnormalities, and the application of a particular surgical procedure alone may not be able to completely solve the problem; multiple surgical methods must be combined to effectively stabilize the patella, and the most appropriate treatment should be selected according to the patient’s actual situation. Knee replacement provides an effective means of correcting tibiofemoral torsion and valgus deformity, and combined with knee extension device rearrangement can effectively correct patellofemoral dislocation and bring the knee extension device into play. Intraoperative points: 1. Thorough release of the lateral support band, moderate release of the lateral collateral ligament, posterior lateral joint capsule, iliotibial bundle, N tendon and other tissues. 2, Excision of part of the patella, reduction of the patella, patellar prosthesis bias built-in. The tibial prosthesis was placed in moderate external rotation 4, slightly increasing the external rotation of the femoral prosthesis 5, slightly increasing the femoral osteotomy if necessary, in order to elevate the joint line (the patella decreased accordingly) 6, overlapping tight suture of the medial support band and medial femoral muscle The six patients we treated were followed up for more than 6 months with good function and no surgical complications.