Good Morning potty girl,
I am glad your surgery went well and you are healing. Good question re your arm incision.
Incisions may be sensitive even to light touch. Some people complain of numbness, tingling, weakness of the little and ring fingers, going up the arm to the elbow. Actively using the hand may be helpful for arm and hand pain.
You may want to put a call in to your Dr. and ask if you should be concerned about the arm numbness.
Again, I am so glad to hear everything else went so well.