HP_0006380 (Knee flexion contracture) is a type of knee joint contracture in which the knee is in a fixed bent (flexed) configuration such that it cannot be straightened actively or passively. Also known as: Flexion contracture of knees, Flexion contractures at both knees, Flexion contractures of knees, Flexion deformity of the knee, Knee flexion contractures, Knee flexion deformity.