Just curious: why numb after swelling?

The several months of mysterious swelling in my left knee has gone away (Coincidentally, totally gone after a long flight, which is what put end to swelling in other knee... ) Cause of left knee swelling is still unknown.

ANYWAY< what I notice now is that the area under my kneecap just to the left, where some of the swelling was, is now pretty numb, like how your cheek feels about an hour after getting novocaine at the dentist. (No numbness occurred on my right knee, where the year before I had a torn meniscus.)

I'm posting because I can't find anything similar on the Interwebs, and I'm just curious if anyone has any idea why it's numb, and whether I should be concerned?

TIA

With no background in this whatsoever, I'd guess that pressure on nerves has deadened them a bit, similarly to when one wears a cast for a long time. As you get used to moving around normally, massaging the area lightly, showering etc, normal circulation will help to restore normal normal sensations.

FWIW, my podiatrist told me last week that its's usual to have different sensations in the two halves of your body after one side sustains an injury, and the difference will persist for decades. My right foot was injured in 1981 but it doesn't really affect me now. However, parts of that foot and ankle aren't as sensitive as my left foot. It's fine.