A treatment, known as Autologous Chondrocyte Implantation (ACI), offers hope for patients with arthritis and knee injuries and could help them avoid total knee replacements. The treatment promotes regenerating hyaline cartilage in a diseased or damaged area of a joint through the implantation of new cartilage cells.
ACI is designed to help patients with an articular cartilage defect (damage in the joint) or early arthritis in the knee, something that can impact younger people in their 20s and 30s, and could occur as a result of a sports injury.
The procedure involves the removal of a sample of cartilage from the patient’s knee from which their own cells are harvested and then grown in a laboratory for around three weeks. These cells, known as chondrocytes, are then put back into the patient’s knee in a second bigger surgical procedure.
“The second-stage operation is an open procedure whereby a small patch is sewn over the articular cartilage defect. The chondrocytes that have been harvested and expanded are then injected underneath this patch where they adhere to the patient’s knee to form what is known as hyaline-like cartilage which resembles the native joint cartilage. Following implantation there is a period of restricted weight-bearing for up to 8 weeks. During this time, physical therapy emphasizing range-of-motion of the knee and strengthening activities is prescribed. Return to light sports activities is typically allowed at approximately 6 months with return to full sports activities between 9 and 12 months following the procedure based on the recovery.” ~ Washington University Physicians
The overall success rate of ACI is approximately 85-90% in allowing patients to return to pain-free activities.
Although ACI was introduced in 1980s, it has since been improved on thanks to modern cell culture techniques and new implantation procedures. New versions of the technique are being developed continuously to treat different conditions related to arthritis and knee injuries.
ACI clinical trials have been running in several locations over a period of years. In December 2016, a new version of the technique was approved by the Food and Drug Administration (FDA) for cartilage defects located at the end of the femur bone (thigh). A slightly modified treatment using the same technique has now been approved in the UK for clinical testing, and it will be conducted under the supervision of researchers from Keele University.