The car is going 50 miles per hour and the front wheel's has a noisy hammering sound. I already changed the CV joint, ball joint bushing and it doesn't get rid of the sound. Any suggestions or possible solutions would be helpful.

Does it only happen at 50 mph straight ahead?

What kind of condition are your tires in? How many miles on the car?

Does the noise change at all during cornering or braking?

No, it happens also with turns.

I just changed all 4 tires two years ago. The car has 168,000 kilometres.

No, it doesn't change when cornering or braking.

Could it be the way the engine is running?
Or perhaps either the engine mounts or the transmission mounts have worn out and are allowing for that noise?
Even at four years, your tires could be worn unevenly and may need a close visual inspection.

My guess is that worn struts have resulted in unusual tire wear. Even if you have replaced the front struts, which is more common, it doesn't take long for worn rear struts to damage a set of tires, as the rear tires are rotated to the front.