once a ligament has been over stretched the elasticity will never come back. Hence the reason why a reco in nessasary to shorten the ligaments to try stop the joint from popping out again.

I have had two recos on my right ankle and the second time they removed the ligament and replaced it with a tendon, as the ligament was usless at stabilizing my ankle. Now my ankle is 95% back to normal.

You really do need physio to rebuild the muscle around the join, without doing it your not giving yourself the best chance of total recovery.

There is no reson why you couldnt box but some advice from a sports physio/doc would be advised first

MAIN POINT: Do see a physio