Total knee arthroplasty (TKA) is the most important treatment for restoring joint mobility and reducing pain in patients with inversion and flexion deformity of the knee, which is one of the main manifestations of advanced osteoarthritis. In addition to accurate osteotomy, a good soft tissue balancing technique is an important guarantee for the success of TKA in patients with valgus knee deformity. Based on our experience and expert consensus, we focus on the soft tissue release technique during TKA in patients with valgus knee deformity in this knee replacement video. I. Medial release technique during TKA for inversion deformity of the knee 1. An anterior median knee incision is made and the medial parapatellar approach is used to gradually release the medial soft tissues by sharp separation. 2. Depending on the degree of medial deformity, the anterior medial joint capsule and deep part of the lateral tibial collateral ligament are stripped from the tibia to the posterior medial corner of the knee under the periosteum to expose the medial aspect of the knee [1]. If medial contracture is still present, the tendon of the semimembranosus muscle, the superficial medial collateral ligament, and the goose foot stop should be released in sequence, and if necessary, the deep layer of the hallux valgus muscle and the attachment of the semimembranosus muscle at the tibial epiphysis can also be released with a bone chisel, checking stability at each step [1-3]. 3. safely expose the superior medial tibial segment and remove the medial upper tibial segment and the distal femur, which may loosen the medial structures. Removal of all bony redundancies of the femur and tibia, as they can push on the medial soft tissues and cause functional shortening of the lateral tibial collateral ligament [1]. 4. The cruciate ligament may be removed to facilitate posterior release. 5. Repeated valgus stress tests are performed during the release to check for satisfactory release. 6. Soft tissue release can be done to completely correct the inversion deformity of the knee, which can be osteotomized as standard. The TKA procedure can generally correct mild to moderate knee flexion contractures by releasing the posterior soft tissues and removing the posterior bony redundancy (Figure 2A, 2B), but if the preoperative flexion contraction is greater than 20°, special surgical treatment is required, such as increasing the osteotomy at the distal femur by less than 4 mm. Intraoperative soft tissue release should be done in steps The soft tissue should be released in steps, checking the knee extension gap as it is released. After the posterior condylar osteotomy, the adherent posterior capsule is stripped proximally to the femur and all bony debris is carefully removed from the knee, especially around the posterior femoral condyle and tibial plateau, followed by assessment of the extension and flexion gaps. In conclusion, valgus flexion deformity is the most common deformity of osteoarthritis of the knee and it is important to be familiar with its surgical operative features.