To micfox, from the latest pic you have provided it looks like the thigh can pop off the hip joint and then you can separate the thigh piece as someone else suggested then take out the broken knee joint glue it onto the lower limb and set it back into the upper thigh piece.
I'm sorry I'm not to up to speed on this figure but I think this can be fixed.
If the thigh cannot be separated without damaging the figure don't try, just use the Loctite and get a long pin then just dab a light amount onto it and transfer it to the piece inside the knee joint on both sides but be sure not to touch any other part in that area, then press against the lower limb onto the broken part for about thirty seconds, if the joint is fairly loose normally then it would be good to move it around while the pieces are married up and drying in this time, but if it is normally a tight joint then it's probably best to wait for a longer period of time before trying to move it.
I hope this helps
I still function.....................while killing threads. ;-)