Cartilage regeneration: Bringing in a new revolution

If you suffer from knee pain, you’re not alone. Each year, more than 12 million people visit their doctors because of knee pain — half of them with damage to cartilage, called articular cartilage. Most of these people have had to live with joint pain and physical limitations. But thanks to new medical advances in cartilage repair, that time has passed. Today, innovative and exciting new developments are revolutionising orthopaedic surgery, enabling surgeons to repair, regenerate or replace cartilage without resorting to the use of artificial joints.

What is articular cartilage?

Articular cartilage is a firm, rubbery material that covers the ends of bones in the knee joint. It reduces friction in the joint and acts as a ‘shock absorber.’ When cartilage becomes damaged or deteriorates, it limits the knee’s normal movement and can cause significant pain. If damaged cartilage is not treated, it can worsen and eventually require knee replacement surgery.

Why does the cartilage not heal by itself?

Cartilage is unable to heal itself as it is avascular and gets its nutrition from the joint fluid itself. Hence, any damage to the articular cartilage is permanent and leads to pain and stiffness.

What are the benefits of cartilage restoration ?

Benefits of cartilage restoration include:

• Pain relief without the placement of artificial substances in the body;
• Preventing the onset of arthritis;
• Re-established performance to pre-injury levels;
• Slowed progression of cartilage damage; and
• Delayed need for joint replacement surgery

How can articular cartilage be restored?

For years, the concept of harvesting stem cells and re-implanting them into one’s own body to regenerate organs and tissues has been embraced and researched in animal models. Similar techniques using autologous cultured mesenchymal stem cells have now shown successful cartilage growth in human knees. Advantage to this approach is that a person’s own stem cells are used, avoiding transmission of genetic diseases.

What are the new techniques available today?

Microfracture: This procedure is performed arthroscopically. During microfracture, small holes are created in the knee bone. The surface layer of the bone is hard and lacks good blood flow. Creating holes in the bone allows bleeding. Blood contains bone marrow cells that stimulate cartilage growth and form fibrocartilage, which covers the injured area.

Osteochondral autograft (OATS): In this technique the surgeon transplant sections of bone and cartilage. First, the damaged section of bone and cartilage is removed from the joint. Then a new healthy dowel of bone with its cartilage covering is removed from the same joint and transplanted or grafted into the hole left from removing the old damaged bone and cartilage. The healthy bone and cartilage are taken from areas of low stress in the joint so as to prevent weakening the joint.

Mosaicplasty: Depending on the severity and overall size of the damage multiple plugs or dowels may be required to adequately repair the joint. Each plug is a few millimeters in diameter. When multiple plugs are moved to the damaged area, it creates a mosaic appearance.

Autologous Chondrocyte Transplantation (ACI): This is a two-step procedure. First, healthy cartilage cells are arthroscopically removed from a non-weight bearing area of the knee. The cells are then grown in the laboratory for around six to eight weeks. An open surgical procedure, called an arthrotomy, is then done to implant the newly grown cells. The newly grown cells are injected into the defect and held in place by a gel based scaffold or using a periosteal patch.

ACI is most often recommended for younger patients who have single defects larger than 2 cm in diameter. ACI uses a patient’s own cells, so there is no danger of a patient rejecting the tissue.

How are these procedures done?

Most of these procedures are done by arthroscopy (camera surgery). In some cases a mini-arthrotomy (small opening of the joint) may be required.

What are the results?

Long-term results have shown the regeneration of new healthy and viable cartilage which is capable of normal function.