Welcome to HCM!
I have gone through your question carefully and it seems that there is an injury
to the nerve at that site, due to fall and chilblains
Had I been at your place, I would have seen a neurologist
, get the nerve conduction study
done for nerves of left lower leg, along with color Doppler to see blood flow of the area.
Usually , the nerves when damaged send out random discharges, which lead to twitches. this can also lead to pin and needle, water droplets like sensations. The pins and needle sensations can also occur due to deficiency blood supply to the area.
you have not mentioned about any kind of treatment or intervention done by you, but from my experience I can say that you can get well with treatment.
It will be good to get blood counts, sugar levels (as in diabetes
these symptoms occur frequently) done together with other tests.
Hope the answer helps you
Feel free to ask more regarding this.
Dr. Manisha Gopal