I’ve found my initial post-op post, that was weird re-reading it, I haven’t read it since I posted it! Here’s the link:
I mentioned in that discussion about the bruising, & someone suggested clamps to keep you still in surgery, but I asked about it before my 2nd surgery & was told it would have been the nerve monitors- one was above my eyebrow & the doctor said it was close to the ‘vein of sod’ as they called it, named because it was very easy to catch & bleeds a lot 
As far as I’m aware the remaining ligament is just left, that’s the impression I got from my doctor. Doesn’t seem to have done me any harm! But obviously check that with your doctor, as they do all have different techniques.