Thank you for your query,
The hook nail deformity
can be corrected by plastic surgery
It is possible to treat the finger and tip deformities by giving minor incisions
and by using fine threads.
If the finger is short, skin grafting
method can be used to reconstuct the finger.
Consult a Plastic surgeon th assess the deformity and to explain the available methods and their appropriateness.
Hope I have answered your query.