Treatment of joint surface problems depends on the size, site and depth of the damaged area. Small areas of damage in older patients are not uncommon, and can often settle over 6-8 weeks with rest and anti-inflammatory tablets. You may, however, find background problems of aching and swelling persist.
Many acute knee cartilage injuries need keyhole surgery to either remove or repair the damaged fragment.
In general, the only repairable injuries are where there is quite a large chunk of a cartilage, preferably with a sliver of bone attached, which can be pinned back in place. In these cases, there is a good chance of healing.
Where the fragment has to be removed, or where you first visit Yorkshire Knee Clinic long after the injury occurred, you may experience pain due to the loss of normal cartilage covering.
The missing cartilage could result in a crater in an important part of the knee, with bare bone in the base. It will not heal up with normal joint surface cartilage. It may heal with fibrocartilage or scar tissue but even here, there can still be problems, in which case you may need one of the following types of knee surgery.
In a “microfracture” procedure, your knee surgeon makes some small holes in the bone. By encouraging bleeding from the bone in the damaged area, a fibrocartilage covering forms. Fibrocartilage is a strong, durable type of cartilage which, whilst not as good as the original articular cartilage, is very effective at doing the same job.
Microfracture is a very useful and simple technique, and at Yorkshire Knee Clinic the procedure can be done as day case keyhole surgery. Depending on the size and site of the microfracture area, you might need crutches for up to six weeks.
Osteochondral autograft transplantation surgery (OATS)
OATS, also called mosaicplasty, is a technique where we take some healthy plugs (cylinders) of bone and articular cartilage from one area of the knee (where it is required less) and put them into the damaged area.
It can be effective in the treatment of some defects, especially when they are deep and include bone loss, but typically only in small areas of damage.
ACI (Autologous chondrocyte implantation)
ACI involves your knee surgeon removing chondral cartilage cells from your knee, creating a culture from them, then reinserting the newly grown cells into the affected area in a second operation. To date, however, results of this procedure have been no better than in microfracture, whilst requiring two operations and greater expense.
What next in joint surface injury?
There is an enormous amount of research going on into treating the damaged joint surface. There is currently no perfect treatment for joint surface injuries, or degenerate damage, and with current technology it is not possible to reliably re-create the normal articular surface.
Stem cells are unspecialised (undifferentiated) cells, which can develop into other cells or tissues. MSCs (mesenchymal stem cells) are stem cells which eventually form cartilage. Much effort is being put into this area, and might be something for the future.
Yorkshire Knee Clinic surgeons are actively involved in this research.