Could Removal Of Tumour In Leg Cause Numbness?

I have been diagnosed with a Schwannoma on my left tibial nerve on my left knee. I have been having some left knee pain for about 3 months. The specialist that I saw for this said that if it is removed surgically there is a chance of not regaining feeling to the lower leg albeit a small chance. I am curious what the risk is when having these types of tumors removed, what is the chance of loosing feeling permanently?