Temporary synovitis of the hip joint in children, also known as transient synovitis, is a non-specific inflammatory disease that is a common cause of hip pain and limp in children. It occurs in children under 10 years old, with a peak incidence of 3-6 years old, more on the right side than on the left side, more common in boys, and most children have a sudden onset. The cause of the disease may be related to viral infections, trauma, bacterial infections and allergic reactions (allergic reactions). The child reports pain in the front or side of the thigh and knee, and physical examination reveals a pain-avoidant gait, mild tenderness in the hip, limited range of motion and discomfort. No fever or low fever, normal or slightly elevated blood count and sedimentation. The treatment of this disease is relatively simple, as the child can be cured by rest, braking of the affected limb, skin traction and other non-pharmacological treatments to keep the joint free of weight and thus reduce the pressure inside the joint to prevent ischemic necrosis inside the bone. Synovitis of the medullary joints is generally considered to be self-limiting, with a duration of about 1 to 2 weeks.