How do I keep my salmon cakes from falling apart?

Ground fish burgers are hard to handle without falling apart unless your making them thicker by hand, to make uniform nice looking patties I grind about 6 fish fillets add a fillet or more of smoked fish as mentioned in comments below if you have it. Add seasonings we use 2 tsp. lemon herb, 2 tsp. pampered chef Bell Pepper Herb Rub, (2 tsp. lemon juice, and one egg whisked together) and 5 potatoes about the size of tennis balls riced. Sprinkle 1/2 the dry seasonings and 1/2 potatoes turn mixture with a fork add the remaining seasonings and riced potatoes. Pour egg mixture evenly and lightly mix ingredients. To make the patties use the open- ended sleeve section of a Tupperware patty press and the pusher. Place the sleeve on an oiled cookie sheet where you want the patty sprinkle instant mash potato flakes, fish breading, or seasoned bread crumbs in sleeve to cover cookie sheet place about 1/3 cup fish in sleeve distribute evenly with your fingers top with more potato flakes or other so pusher doesn't stick, press your patty and slide open ended section up while still keeping pusher in contact with top of patty. You will now have a nice patty ready for the oven eliminating additional handling and the problem of them breaking up.

In addition to the advice above re: adding egg and some sort of crumb - I always make any kind of fishcake at least a half to one hour before pan-frying them.

I form them and coat or dust them very lightly in panko/bread crumbs - gives a slight outer crust, which is both nice texturally and also helps keep them together in the pan. Then let them rest in the fridge for a bit - this really makes them more cohesive when cooking.

It's hard to say without seeing your recipe. I use 1 egg for 1 pound of salmon, but I also use a little creme fraiche and mustard. Mayo works as well.

http://www.food52.com/recipes/7208_salmon_cakes_for_a_busy_week

I use egg white to bind my turkey burgers, and that would work well in your salmon cakes where you may not want a lot more fat or filler.

Ritz crackers work great as a binder too- the butter in the crackers helps keep cakes like that together. More egg should help as well.

If they are too dry they will fall apart, so adding another egg might help - I often actually use mayo as my binder and it works quite well. Are you putting both breadcrumbs and egg in them? Your thought of flaking the salmon into smaller pieces may also help. Big chunks don't work very well. I usually mix my salmon cake mixture up so it's almost a whipped consistency!

You probably need more egg and perhaps some Panko crumbs.