van Drongelen S, et al. - Twenty-two unilateral hip OA individuals who were scheduled for total hip replacement were involved in the study in order to ascertain whether total hip replacement surgery impacted radiological leg alignment (Hip-Knee-Shaft-Angle, femoral offset, Neck-Shaft-Angle and varus/valgus alignment) and which of these parameters could describe the joint moments, along with the gait kinematics. In the patient group, the joint moments following total hip replacement did not vary from healthy controls, whilst radiological leg alignment parameters altered notably following the total hip replacement. A combination of these radiological leg parameters and the deviating kinematics, particularly the varus alignment, define the joint moments in the frontal plane during gait following total hip replacement surgery. For surgeons, since varus alignment could improve the knee adduction moment and the risk for OA of the medial knee compartment, it is essential not to build too much of a structural varus alignment through implanting the new hip joint.