Cartilage is a smooth shiny tissue on the ends of bones that form joints. It helps the joints move smoothly. As you are probably aware damaged cartilage causes joints to be painful and difficult to move.

Cartilage is not like skin, it doesn't have the ability to repair itself properly. Any repair tissue that does form is not like normal cartilage and it doesn't work very well.

ACI stands for Autologous Chondrocyte Implantation. In this surgery cartilage cells are taken (usually from the knee) and are grown in a lab before being put back into the same patients damaged joint.

Initially you will be assessed by your surgeon to see if you are suitable for this treatment. You will then be asked to have an MRI scan of your affected joint. You will also be asked to fill in a questionnaire regarding your pain and mobility.

On the day that you come into hospital a member of the team will see you. Samples of your blood are taken, as we use this as 'food' for your cartilage cells. The first operation is usually an arthroscopy (keyhole surgery) to take a sample of healthy cartilage. The cartilage that is taken is grown in our lab in compliance with all European Standards. After three weeks you come back to hospital for the second procedure. This involves opening up the affected joint, cleaning the cartilage defect and covering it with a patch of bone lining (periosteum) which is stitched and glued in place. The cells are then injected under the patch and the joint is closed. Go to ACI page for a more detailed description.

For the arthroscopy (keyhole surgery) most patients are in one night, the night of the operation. For the bigger second procedure, the arthrotomy, you would normally expect to be in hospital at least three nights, but most people are in for one week.

The arthroscopy is not usually too bad and painkillers by mouth are normally all that is needed. The arthrotomy however can be uncomfortable and stronger painkillers may be needed. There are many different things we can try and you will not be left to suffer.

Quite a lot I'm afraid. Post operatively you will be required to put in a lot of work if you want to get the best out of your surgery. Initially on the ward you will see our physiotherapist who has devised a superb program of rehabilitation.

Initially probably not much! The cartilage cells need time to settle down and organise themselves in much the same way that we do when we move home. It may be up to 12 months before things are good. Our research has shown this and that the improvement seems to continue with time.

The knee joint is most commonly treated with ACI. In addition, the ankle, hip and even the elbow have also been treated with this technique.

ACI was pioneered in Sweden in 1984; so far worldwide 6000 people have been treated. Here in Oswestry we have treated 120 patients so far. The Robert Jones and Agnes Hunt Orthopaedic Hospital has a long research history. We have a team of experts involved in our cartilage program and we even grow the cartilage cells in our own onsite lab. For this project we use a computerised database that stores information about our patients, the surgery they have and the progress they make. We use this information to assess and improve the treatment we offer. We have also published some of our results and presented them at meetings worldwide. Any information we publish however will not allow individual patients to be recognised, as we do not use names or hospital numbers as identification.