Based on the information it seem that you are feeling numb at the tip of the penis after woke up form anesthesia
for leg surgery
and when you called your doctor said it way far from the penis nerve.
I think their was some issue created if you were given spinal anesthesia, if not its nothing related to the surgery of the foot that may give rise to that issues.
If the issue remains persistent for a while I recommend have it checked by neurologist
1) Consult local neurologist if the problem stays more then a week.
2) They may need a CT Scan
of spine to check if the nerve may be damaged around its exit point from the vertebral
3) Take the list of medication as some time medication may be the cause of such problems.
Dr. JAY PATEL.