Hurt wrist in april, had mri, shows ganglion cyst, effusion and tear but dr says nothing wrong, why? painful and hurts to move fingers.

MRI explains it: "effusion and tear" of the structures in the wrist or hand, could cause the symptoms. Not sure why your doctor said "nothing wrong". Sometimes a surgeon will say "nothing I can do" and a patient hears "nothing wrong". Doctors who specialize in PM&R (or Physiatry), use non surgical ways of treating soft tissue injuries. Might be worth seeing one. Bringing previous records is always a good idea