Talk to Rheumatologist on Proximal Interphlengeal Joint Dislocation

2 months before my brother got an accident hw got injuries on wrist and little finger which was settled down by doctors and put plaster on his lower arm ... aftr a month after removal of plaster X ray exposed his ring finger’s proximal interphlangeal joint dislocation doctors tried it to reposition manually but it could not because of stiffness splint was recommended for a month after a month the condition was same .... i want to ask that is this a case of orthopeadic surgeon or plastic surgery .... and what will be the possible treatment for this condition .... we have to move towards surgical treatment for this issue...? X ray file has been uploaded also