I'm looking for a book

I remember very little about it, so it's difficult to find. I don't remember title or author, but I think the title had the word "planet" in it. I read it in high school so the book came out before 1977. It's a near future story about a planet (it could be earth). That is under a totalitarian regime. There's a character who has robotic legs. I think he was in prison and escaped. Anyway he is so upset with the government that he starts doing what we would call now terrorist acts. Anyway, someone within the government also wants to revolt and starts hearing about the disabled guy outside. He starts using what the guy's doing outside to confuse the government leaders. The disabled guy outside starts realizing that someone inside is using his activities to help cause trouble within the government while he's causing trouble outside. So they start coordinating with each other without ever being able to actually talk to each other. At some point the disabled guy gets caught by having his robotic legs shot out from under him. That's all I really remember. Anyone have any ideas about what this book could've been?