If one or more of the child's joints have become infected by bacteria, it is called a permanent joint infection or septic arthritis. Usually, it is the large joints, such as the hip joint or the knee joint, that become infected.
Here you can read about skeletal, joints and muscle infections.
If the baby's skeleton is attacked by bacteria, it is called skeletal infection or osteomyelitis. It is an unusual disease. The infection usually sits in the long legs, for example in the leg of the arm, the femur or in the lower leg.