Stiff knee is a deformity in which the knee joint is fixed in an extended or flexed position due to trauma or immune disease (e.g. rheumatoid arthritis, ankylosing spondylitis, etc.). The loss of mobility in the knee joint, which was originally flexible enough to walk, can seriously affect the patient’s daily life and physical and mental health. These patients have a strong desire to change the function of the knee to improve their quality of life. Stiff knees are often caused by bony or fibrous fusion resulting in adhesions in the knee joint, with the quadriceps extensor mechanism fixed in a certain position and loss of flexion and extension. The degree of surgical exposure, surgical release, and balance of the knee extension and flexion gap are difficult, and the risks and complications of surgery are high (e.g., patellar tendon rupture, tibial tuberosity avulsion fracture, etc.), and stiff knees were previously listed as a contraindication to knee replacement. Although it is difficult and risky to perform total knee arthroplasty for a stiff knee, a well-prepared preoperative plan, adequate intraoperative release of the knee extension device, and active and appropriate postoperative rehabilitation can provide satisfactory results and meet the patient’s strong desire to improve the quality of life. Auntie Li (pseudonym) was a 68-year-old patient who had suffered from rheumatism for more than 30 years. Before surgery, both knees were fixed in flexion at 20 degrees and walking was severely inconvenient. Five months ago, she underwent a left knee replacement at the suggestion of our joint surgeon, and after the surgery, her left knee was able to reach 100 degrees of flexion after exercise, which basically met the needs of daily life. Seeing the good results of the left knee, Auntie Li and her family had new expectations for life and recently came back to our hospital for the right knee replacement. Dr. Wang Kun, the chief surgeon, and his team of joint surgeons not only appreciated the patient’s full trust, but also felt the patient’s strong demand for restoring the function of the knee joint and the responsibility to do a good job in the surgery, and made a fine surgical plan before the surgery, and made a suitable release of the quadriceps muscle and finely balanced the knee extension and flexion gap during the surgery. Post-operative rehabilitation was carried out gradually with the help of the medical staff. At the time of discharge, the right knee flexion had reached 40 degrees. After the rehabilitation exercises at home, it is expected that a greater range of motion can be achieved after the quadriceps muscle is repaired, and going to the street to buy food and go to the park is no longer a thing out of reach for Auntie Li. Auntie Li’s pre-operative and post-operative X-ray control Uncle Wu (a pseudonym) is a 46-year-old local cadre from Qinghai, who injured his right knee in an accident when he was young, and after conservative treatment, he developed osseous ankylosis of the knee joint, fusing the three compartments of the femur and patella and tibia together, and dysplasia of the medial femoral condyle. After being introduced to our hospital, he learned that we had extensive experience in treating stiff knees with artificial knee replacements and came all the way to Guangdong for treatment. Dr. Wang Kun, the chief surgeon, and his team of joint surgeons welcomed his minority friend from far away and made a strict preoperative plan for this severely deformed knee. After the surgery, Uncle Wu was happy to see that his knee, which had been flexed and fixed for more than 30 years, had regained its mobility, for which the family expressed their sincere gratitude. Pre- and post-operative x-rays of Uncle Wu’s knee are no longer an unattainable dream for patients suffering from a stiff knee, who have regained flexion and extension mobility. Although there are many technical difficulties and certain surgical risks associated with the replacement of a stiff knee, with adequate preoperative planning, proper intraoperative soft tissue release and balance of flexion and extension gaps, and proper postoperative rehabilitation, good results can be achieved and restoration of knee mobility can be expected. It is no longer a dream to come to Zhongshan San Hospital with a limp and leave it with a vigorous stride.