Remember that fetch() and fetch_row() are two different things, and differ in the way to use them.
- fetch() is used on a statement (like an executed prepared statement) and needs to be used in association with bind_result().
- fetch_row() is used on a result (like the result of query()).
As a consequence, if you want to use to use fetch_row() with an executed prepared statement, first you'll have to get the result out of this statement with mysqli_store_result() or mysqli_use_result().