Chondoitin (shark cartlilage)is excellent for human cartilage repair - however, (and this may sound somewhat 14th century) If you have access to a crop of the herb COMFREY, you have a partial answer/aid there. You pick a couple of handfuls of the leaves, mash them up and boil them like a tea: About 5 minutes will usually do (make sure the water is boiling before you drop in the comfrey). Let it come to the boil again and allow the 5 minutes at a "rolling boil" - your wife will know what that is, if you don't. Allow it to cool and decant it into a water jug or sterilised bottle (sterilised with boiling water is fine) and drink only ONE small wineglass-full per day. Comfrey is also known colloquially as "Knitbone" and has brilliant effects on rebuilding broken bones and repairing cartilage - provided the cartilage damage is not profound - (that is it hasn't been 'pulped' like the cartilage in my knee). I have used comfrey for years for injuries and found that bone fractures heal up to a third faster (5 weeks as opposed to 8) and I have seen it in others as well.

Just a suggestion