The players had both undergone medicals this week and were meant to exchange places on loan with obligation to buy at the end of the season, as they were valued at €25m.
However, Inter seemed to pull the plug when they demanded extra fitness tests on top of the traditional medical for Spinazzola.
Then they asked to change the terms of the deal, making it a loan with option to buy, to be activated after 15 competitive appearances.
The clubs ended up discussing what constituted an appearance, Inter demanding it meant at least 45 minutes on the pitch.
At this stage, talks broke down completely and both clubs walked away from the deal.