Long time ago, when my mom fell and broke her knee cap, we did not even know where to find a crutch that is most comfortable. We wanted to buy from the hospital but they privately told us not to because the price is highly marked up.
So, they suggested we hunt around one of those home medical equipment stores and get it. We still cannot find but luck was on our side. One of her friend who just had a fall but had recovered lent hers to my mom. In the end, we did not have to buy and I was glad that she recovered well enough to walk again after some physio session.
If you are ok with it, do check out the link because you never know when one can have a stumble and fall, can you?