When it comes to fractures, the best outcome occurs when bones are in the most accurate anatomical position to heal. Without a good line up there’s a risk of delayed healing or even nonunion.
When the bones are lined back up, it’s called reduction. Good reduction isn’t always needed in children. Children have the unique characteristic of growing bone to help in the process. There’s also a step called bone remodeling. When new bone forms around the fracture, there’s usually more than is needed. The body then starts to remodel the bone to remove the excess bone.
Each person (child) is different. Sometimes the fracture healing and remodeling is so perfect it takes a skilled radiologist to detect it on X-ray years later. In other cases, a callus of bone around the fracture site remains.
There is a chance that the bones will heal in a deformed position. Studies show this kind of healing will affect function. Surgery to reduce the bones has its risks too. Nerve damage, infection, and poor healing can result from surgery.
Based on the current X-rays and experience with past cases of this type, your surgeon can give you the best odds for healing with or without surgery. If you decide to go with casting and bypass surgery, then you can have the arm X-rayed every couple of weeks to see how the healing is progressing.