I had reconstructive surgery to my ACL, MCL and I also tore my meniscus in multiple places and these were also fixed. In order to reconstruct my ACL and MCL they took hamstring grafts from both knees. The figure below shows the main structures in the knee and you can see the ligaments I reference above.
Ahead of the surgery I did a bit of research to try and understand exactly what I was in for. It became apparent quite quickly that the treatment of knee injuries is far from an exact science and there is still a lot of uncertainty on exactly how to treat ligament injuries with the jury out as to if surgery is necessary in all instances.
The research I did indicated that you don’t generally have reconstructive surgery on the MCL unless you have also damaged the ACL. The main reason for having the surgery on the MCL is that research has found that the probability of ACL failure is greatly increased with a ‘slack’ MCL. The same can be said with respect to the meniscus tears and having these fixed makes the chance of success with the ACL much more likely.
Ultimately I have a massive incision just to the right of my left knee (~ 12 inches) where they fixed the MCL (I think this is so large as they have to reattached the MCL at three different place to ensure the greatest chance of success) and then two further 1 inch incisions where they took the hamstring grafts. For the left knee I think they may have also fixed the ACL through this incision.
The surgery took 5 hours in total and for more detail on the what happened on the day I had the surgery you can be found here see this post here.