You can do it! It's not going to be the easiest route in the world, but people have gotten in with that score--the key will be excelling on other parts of your application such as STEP 2, research, etc. Check "Charting the Outcomes" published by the NBME for more details. Don't give up if it's what you really want.
In one of the big US cities, quite a prestigious University Residencies I met US-IMG resident with Step 1/2Ck like 22+/22+. He spent some time on research and matched into surgery.