In this pic you see the broken knee and the screw with the head cut off. Here's my post on how I fixed Venus McFlytrap with step by step instructions.
This post is just a reminder that it can be done. For some reason I didn't get a shot of the knee fixed. Next time I go over I'll take a pic and add it to the post.
Side shot of the broken knee so you can see what break I'm repairing.
Good luck fixing your doll :). It's easy!