I had microfracture surgery of the knee. i am on crutches & after i am up & about for a bit with partial weight the foot gets real cold & hard to war?

Check with your surg: You need to discuss these concerns with your surgeon. Two things that come to mind when you mention a cold foot upon standing is poor circulation to the foot or secondly, possible nerve damage which is not uncommon with surgery. You didn't mention how long ago you had surgery, but often it can take up to a year for the nerve to regenerate following surgery.

Knee surgery: You should always discuss any concern with your surgeon. He/ she would want you to call.