What's the best way to get crab cakes to hold together?

I made crab cakes for dinner. In terms of flavor, they were fine. However, they kept trying to break into chunks whilst frying.

When I was mixing them, they seemed too wet, so I threw in some more cracker crumbs. I didn’t want to, but it seemed the only way to get them to bind a bit more. I also put them in the refrigerator for 20 minutes prior to frying. The wet ingredients were mayo, egg and a touch of lemon juice. The crab was canned; I drained it well prior to mixing.

So what am I doing wrong here? The flavor was good, it was just the cakes were trying to chunk apart!