Cartilage – Autologous Chondrocyte Implantation (MACI)
Articular or hyaline cartilage is the tissue that covers bone surface of the knee, which helps in smooth interaction between the two bones in knee joint. Articular cartilage often gets damaged because of direct blow to the knee, trauma, accidents or fall causing pain, swelling, stiffness, and limited movement of the knee. Furthermore, it has less capacity to repair by itself because of no direct blood supply to cartilage. Therefore, cartilage transplantation helps to replace the damaged cartilage and restore the normal functioning of the knee.
Matrix-induced Autologous cartilage implantation (MACI) is a technique of replacing the damaged cartilage by transplanting healthy cartilage. It is indicated in patients with full thickness large areas of articular cartilage damage. However, it is not recommended for patients having osteoarthritis.
Surgery is performed in two stages. In the first stage, the area of damage is identified to determine if ACI procedure is appropriate. The sample of a healthy cartilage cells is obtained from the damaged knee through arthroscopy. The cartilage cells are cultivated in the laboratory for 4 weeks.
In the second stage, incisions are made in knee and the defect site is prepared. The membrane with the cultured cells is then fixed on to the defect site. The area is cleaned and incisions are closed. With time, the cultured cells will mature to articular cartilage.
Complications of Autologous Cartilage Implantation
- Improper integration of the newly implanted cartilage cells
- Infection of the knee
- Stiffness of the knee
A knee brace will be applied to restrict movement of the knee and you will likely be restricted in weight-bearing for six weeks. Physiotherapy is recommended to regain the movement, reduce swelling, and increase muscle tone. Rehabilitation program includes various strengthening and stretching exercises which strengthen the quadriceps and hamstring muscles. It also helps to stimulate the growth of cartilage cells. With the consult of your doctor Dr. Patel, you will be able to return to sports.
Other cartilage transplantation techniques include:
Osteochondral Autograft Transplantation: Osteochondral autograft transplantation system (OATS) is a surgical procedure where plugs of bone and cartilage are taken from the non-weight bearing areas of knee, from the same individual and transferred to the damaged areas of the joint. This method is used to treat smaller bone and cartilage defects since the graft size, which is taken from the same individual, will be limited.
Osteochondral Allograft Transplantation: In this procedure a healthy bone and cartilage plug is taken from a donor from the tissue bank and transplanted to the area of cartilage defect.
Following cartilage replacement Dr. Patel will recommend immediate restrictions in weight bearing as well physical therapy to help restore mobility and to impart the strength to the affected joint.