Hello, and welcome to Mayo Connect. We are community of people living with a variety of health conditions, who share our experiences and try to help each other along the way.
I cannot speak personally about numbness after knee replacement, but here is what I do know. I had ACL/MCL surgery after an injury 25 years ago, and nerves were damaged in the process, leading to numbness in my lower leg, and a feeling of not knowing where my foot was. Afterward, I progressed to a period of tingling, and finally after about 1 1/2 years, the nerve healed. At one of my 5 hip replacement surgeries, a nerve in my leg was cut or damaged and that took over a year to heal - that wasn't quite as bad because only my thigh was numb. My sister-in-law had a knee replacement last November, and her leg had numbness that progressed to needle-like pain over several months. When I saw her in October she said feeling is back except in a small part of her lower leg.
I am going to suggest to the moderator that she move this discussion to the joint replacement group so people who may have experienced this can join in.
Sue

@monielove I'd like to extend my welcome. Since your knee surgery 5 weeks ago you are experiencing numbness and you are curious if, "a nerve could have been cut [during surgery] causing the numb and tingling feeling?"

You will see that I have moved your question into a discussion in the Joint Replacements group where members are currently discussing knee replacements so you could more quickly connect and get support. You will notice members like @eeppeerr88 @lil1952 @cobweb have experience with this topic and may be a good resource for you. I also encourage you to scroll back through the comments to find previously shared suggestions.

You mention a tingling feeling. Does this mean that there has been some improvement in the numbness since surgery?