Try using a walking pole with a wrist-strap. They're designed to keep the hand upright, rather than pressing down on the handle of the walking stick, and are much more comfortable. They're also adjustable so you can get them to exactly the right height, which could make the difference between major backache and bliss. I use the Leki brand for hillwalking, but there are others equally as good. As a plus, when you're knee's fully healed you can still use the pole for walking/hiking.