Watch your child carefully for any skin problems. Sometimes the harness can cause skin irritation and other skin difficulties. Keep all medical appointments. It's important to have an orthopedic surgeon examine the hip on a regular basis.
The goal is to develop a nice round head of the femur that fits into the socket of the hip. An incorrectly fitting harness can result in flattening of the bone or other abnormal changes in the growth plate.
It's also possible the child can get "stuck" in this position. Loss of hip motion can occur; this can affect walking later.