Knee joint stiffness often occurs after distal femur fractures, significantly reducing the patient’s quality of life (Hahn et al., J Bone Joint Surg 92(2):217-221, 2010, Pal et al., Int J Sci Res 5(7):2137-2140, 2016). Most often soft tissue releases are used to address the contracture (Ding and Khan, Biomedicine 9(3):39-45, 2019). However, in cases where contracture chronic and complex, then even after soft tissue release, it is not possible to acutely achieve the desired range of motion (ROM) of knee joint. In such cases, external fixation is additionally used (Lee et al., J Orthop Trauma 24(11):709-715, 2010). In the presented case, the successful treatment of persistent post-traumatic extension contracture of the knee joint using soft tissue release in combination with external fixation using the Ortho-SUV Frame orthopedic hexapod, (OSF) is demonstrated. The “multi-total residual” option of OSF software calculates the change in struts lengths to reproduce the kinematics of knee joint movement, including gradual flexion, sliding, and rotation. The period of passive improvement of ROM 49 days included 5 full flexion-extension cycles: the first cycle was 21 days, the last cycle - 4 h. As a result, active ROM full extension to 120° was achieved. © Springer Nature Switzerland AG 2015, 2024.