Thank you for your query.
The type of fracture
which your daughter sustained occurs in about 15% of childhood long bone fractures
. Type 2 Salter-Harris fracture takes approximately 2-3 weeks to heal which is evident from the periosteal reaction seen in your daughter's case. As this fracture involves the growing end of the bone, the orthopedic surgeon wants to ensure that the growth of the bone is not affected later in life. With this in mind he may suggest surgery to approximate the fractured ends for a better healing for which he will have to use pins and they may be removed once the purpose is served.
It is difficult for me to comment whether your daughter may require surgery (or what is the percentage that she may need surgery) without having a look at the X-rays before and after the reduction.
I hope I have answered your query to your satisfaction.
Wishing your daughter all the best..