Running a sword all the way through someone and out their back looks cool and sounds like a cool death for your villain or a neat description to throw into your Hero's fight, but there are some things to keep in mind.
First the human body sucks... no really, it does. When a body is pierced it sucks around the wound, essentially trying to close back up. That's why we (students of swordsmanship) are taught to rotate the blade while we're making a thrust. This not only does a lot more damage (think cork screw instead of a straight in and out stab) but it also prevents the body from sucking around that wound.
What does sucky bodies have to do with running someone through? Well, the body will suck around the sword as well, making it very difficult to pull it back out again. You don't need to get stuck on a bone for your sword to stick in the body. The best way to understand this is to imagine walking in mud. You put your foot down and it sinks pretty easily, then when you try to pull your foot back out again the suction tries to hold on to you. The deeper the mud (the deeper you stab into the human body) the harder it is to get out.
If you go all the way through someone, there's a good chance that you will have to plant your foot on the person to get enough leverage to get the word out again.
This brings me to my second point, if you're fighting multiple opponents you don't have time to be yanking and pulling at your sword trying to get it free (unless of course that's an element you want to use in your scene, but make sure the actions match the consequences).
You don't need to run a sword completely through someone to kill them. All the vital organs you are aiming for are within three inches of the skin.
So watch how deep you have your sword blows penetrate and make sure the consequences match.