Cartilage transplantation involves taking a sample of a patient's own cartilage, growing it and multiplying it in a lab and then inserting in back into the knee 6 weeks later
ACI = autologous cartilage implantation (the cells are injected under a membrane)
MACI = matrix-induced ACI (the cells are provided impregnated into a sheet of collagen)
The results of cartilage transplantation are about 80% good-to-excellent at 5 years follow-up

Autologous Chondrocyte Implantation (aka Transplantation) is a procedure whereby an initial operation is performed to harvest some cartilage from a non-weight bearing area of the joint. This cartilage is then sent to a lab where it is grown in culture, to multiply the number of cells. Some weeks later (about 6 weeks) a second procedure is performed whereby the joint is opened up, the bare area of bone where the cartilage is missing is cleaned, a membrane of collagen (a natural material) is fastened over the defect and the cultured cells are injected under the membrane. This gives an appearance not too dissimilar to The London Dome!


Picture showing harvesting of cartilage cells from a 'non-weight-bearing' area of the knee (Stage 1 surgery).	Stage 2 surgery - the cells have been multiplied in the lab and are injected back into the knee under a covering (a membrane of collagen).

ACI was popularised by Lars Petersson in Finland, and it is now practised in various specialist centres in the UK. Legislation has recently been put in place so that only registered centres are now allowed to provide tissue donation for procedures such as cartilage transplantation. The surgeons of SPORTS ORTHOPAEDICS UK are fully trained in this procedure, and work within fully accredited centres for tissue transplantation.

Article written by

Mr Ian McDermott

Consultant Knee Surgeon and Hip Surgeon, London & Northwood

Last updated 13/01/10