Hip arthritis and necrosis of the femoral head are different in terms of pathogenesis, clinical manifestations and pathological changes, as follows. 1. Pathogenesis: Hip arthritis is generally due to acetabular dysplasia, immunity, degenerative diseases and other factors causing hip joint inflammation. Necrosis of the femoral head is caused by fracture of the femoral neck due to trauma, long-term use of hormonal drugs and other reasons. 2. Clinical manifestations: Hip arthritis is mainly dominated by local pain symptoms, necrosis of the femoral head pain is generally more intense, severe can be accompanied by significant shortening of the limb, activity limitation and other symptoms. 3. Pathological changes: Hip arthritis pathological changes include cartilage degeneration, degeneration, sclerosis, hyperplasia, etc., and ultimately joint space narrowing. Necrosis of the femoral head is caused by apoptosis, collapse and deformation of bone structure due to abnormal bone metabolism caused by insufficient blood transportation. Hip arthritis and necrosis of the femoral head can cause serious deformities in the late stage of the disease, and it is recommended that the patients consult the doctor in time, and carry out regular treatment, so as not to cause adverse consequences.