fractured lateral malleolus

Hi! GOodmorning! i'm just wondering if the treatment done to my father who suffered from a motor vehicular accident was appropriate.

Radiological Findings: There are fractures (suspiciously old) of the medial malleolus of the right tibia and distal fibula, with no gross dislocation seen. No other demonstrate bony abnormality in the projections taken.

Impression: Consider old Non-displaced Fractures, Distal Tibia and Fibula, Right

We followed the doctor's suggestion to undergo him in an ORIF. Is it right that he underwent into a surgical procedure? what will happen if he did not went into it? does non-surgical methods(eg. cast) can help me instead of an operation?

His latest X-ray findings revealed: Follow-up study s/p ORIF show a metallic screw transfixing the fractured lateral malleolus. The rest of visualized bones are intact.

I hope you can answer my questions. any advices or opinions will be very much appreciated. Thank you very much! have a great day! =)