1. Growth arrest may occur at the knee as a complication of chronic disability of the lower extremity.
2. Growth retardation of the epiphyseal discs precedes permanent arrest. This retardation is due to partial degeneration of the cartilage as the result of atrophy of disuse.
3. Arrested growth occurs later, due to complete degeneration of a portion of the epiphyseal plate and the repair of the defect so formed by a bony bridge.
4. This complete degeneration is probably due to some secondary factor, such as the abnormal stresses present with a faulty gait.