Chondral Repair Surgery

The bony surface of the knee is covered by articular or hyaline cartilage which helps in smooth interaction between the two bones in knee joint. Articular cartilage withstands pressure of the knee during daily activities and the activities that may have more impact on knees such as sport activities. Bearing more weights may cause damage to the cartilage and because of poor regeneration capacity of cartilage knee can be easily damaged causing chondral injuries and osteoarthritis.

Some of the common causes for chondral injuries include sports injuries, trauma, and overuse of the knee leading to symptoms such as joint pain, swelling, catching or locking sensation. Chondral damage can be diagnosed by imaging tests such as X-ray and MRI scan which will confirm the injury to provide necessary treatment. Some of the chondral repair procedures include:

• Microfracture – In this procedure small and multiple holes are created inside the bone (subchondral bone) to induce bleeding and stimulate the formation of fibrin clot. When bleeding starts, the primitive cells from the bone marrow migrate to these places and fill it with fibrocartilage tissue which will promote healing.
• Arthroscopic debridement – The loose and inflamed tissues in the joint lining are washed (lavage) and evacuated using vacuum. Excess growth of the joint lining causes the cartilage to fold and releases destructive enzymes into the joint space which causes swelling and pain. This procedure is performed using arthroscopic techniques.
• Osteochondral autologous transplantation – Osteochondral autologous transplantation (OAT) is also known as mosaicplasty. In this procedure, hyaline cartilage is harvested from the femur bone of the same individual (autograft) and transplanted to the damaged cartilage of the knee. The cartilage cells that are transferred will grow and promote healing. This procedure can be carried out arthroscopically or through open surgery.
• Autologous chondrocyte implantation (ACI) – In this procedure, the normal cartilage cells are harvested from the knee and grown in laboratory for about 4 to 6 weeks. A patch is harvested from the thick tissue of the tibia. This patch is sewed over the damage cartilage and the cultured cartilage cells are injected under this patch and allow it to grow. The cultured cells will repair the damaged cartilage and promotes healing.

Severe cases of articular cartilage damage will lead to a condition called as osteoarthritis where the cartilage begins to wear and tear producing a knee deformity. The treatment options to correct this deformity include osteotomy and replacement procedures which help to relieve pain and prevent further damage of the arthritic joint.

• Osteotomy – In this procedure, the deformed bone is cut and the deformity is corrected by bending the bone to fix it in the correct position with the help of metal screws or plate, or the two edges of the cut bone are joined by metal staples or screws. These metal implants will be removed after the deformity is corrected or can be left permanently inside. This procedure helps to correct the deformity and protects the joint by allowing the weight to be taken on the other knee joint.
• Replacement – Total knee replacement procedure is done to the painful and stiff knee joints that are damaged by arthritis. In this procedure the damaged surface of the knee is cut and the two surfaces are replaced by an artificial material such as metal shell. The space between the two metal surfaces is filled by high density polyethylene which is resistant to wear and tear.