What Causes Radial Nerve Palsy After A Surgery In The Lower Shaft Of Humorous?

hi...i had a facture in the lower shaft of the humerous. I was operated 4 months back. Post operation I had a radial nerve palsy. I was told by my Doctor that the palsy will be cured in 3 months. I am still suffering with it.Kindly advise if any medication is required.