Minor cartilage damage may improve on its own within a few weeks, but more severe damage will often require surgery.
Severe cartilage damage doesn't tend to heal very well on its own, so surgery is often necessary in these cases.
Surgery is usually performed using arthroscopy – a type of keyhole surgery where special instruments are inserted into the joint through small cuts (incisions) – although sometimes larger incisions need to be made.
It's normally carried out under general anaesthetic, where you're asleep.
- lavage and debridement - the joint is cleaned out to remove any loose tissue, and the edges of the damaged area are trimmed to make them smooth; it may sometimes be possible to repair the damage at the same time
- marrow stimulation (microfracture -tiny holes are made in the bone beneath the damaged cartilage, which releases bone marrow into it; the marrow cells then begin to stimulate the production of new cartilage
- mosaicplasty - small plugs of healthy cartilage from non-weightbearing areas of a joint, such as the side of the knee, are removed and used to replace small areas of damaged cartilage
- osteotomy - the alignment of the leg is altered slightly to reduce pressure on the damaged area and improve pain; this usually involves adding or removing a wedge of bone from the shin or thigh bone, and the bone is fixed with a plate until it heals
- joint replacement - replacing the whole joint with an artificial one, such as a knee replacement or hip replacement, is occasionally necessary if the damage is particularly severe allograft osteochondral transplantation (AOT) – similar to mosaicplasty, but the replacement cartilage is obtained from a recently deceased donor, and it's used to repair larger damaged areas
- autologous chondrocyte implantation (ACI) - the surgeon first takes a small sample of cartilage cells from the joint; these are then used to grow more cells in a laboratory and the new cells are used to replace the damaged cartilage
- artificial scaffolds - a special patch or gel is used to repair the damaged cartilage; it may be used in combination with marrow stimulation or on its own
You'll usually need to take things easy for at least a few weeks after surgery, and you may not be able to return to strenuous activities and sports for several months.