Femoral head necrosis does not cause paralysis, it only causes functional limitation of the lower limbs. In the advanced stage of femoral head necrosis, femoral head deformation, joint stenosis and secondary osteoarthritis occur, which will cause loss of function of the affected hip joint and increase joint pain, which will affect the quality of life of the patient, such as limited walking, but will not cause paralysis. Most paralysis is caused by damage to the spinal cord, such as compression and damage to the spinal cord caused by a car accident. In addition, lumbar spine diseases, such as lumbar spine fracture causing damage to the spinal cord or lumbar disc herniation causing damage to the spinal cord, can lead to paralysis in these cases.