The head of the femur can be replaced in its correct (anatomical) position. This is a major operation. The hip joint to be opened and the growth plate very carefully dissected to allow the femoral head to be repositioned and held with 2 or 3 screws. Patients require 7 days of bed rest following this procedure and up to 2 months non-weight bearing with crutches. The results of this operation are better than other procedures if it is successful. However, there is a risk of damaging the blood supply to the head of the femur (Avascular necrosis). This can occur in 5 to 10% of cases. This can rapidly lead to osteoarthritis of the joint. The risk of avascular necrosis can often be assessed prior to surgery depending on the severity of slip and rapidity of onset of symptoms.