Differential diagnosis of cerebral palsy – skeletal diseases 1. developmental dysplasia of the hip (DDH) is a kind of unilateral or bilateral hip instability and poor alignment of the femoral head and acetabulum due to genetics, breech birth, leg binding and other factors It is a disease in which the head of the femur and the acetabulum are poorly aligned. It can be diagnosed by pelvic X-ray, CT and MRI. 2, congenital laxity of ligament (congenital laxity of ligament), delayed development of gross motor development, delayed walking alone, unstable walking, easy to fall, difficulty in going up and down stairs, significantly increased joint range of motion and hyperextension, adduction or abduction, normal muscle strength, normal tendon reflexes, no pathological reflexes, no convulsions, normal intelligence, may have a family history, symptoms gradually improve with age.