About
Articular cartilage is a white, glistening tissue that covers the ends of the bone involved in the formation of joints. The function of the articular cartilage is to provide a low friction smooth gliding surface allowing the joint to withstand weight bearing through the range of motion. Articular Cartilage can become injured because of trauma or due to lack of blood supply to a particular segment of cartilage or due to degeneration (wear and tear). Injury to articular cartilage does not heal on its own due to lack of blood supply. Damaged cartilage cannot cushion the joints during movement and the joints may rub over each other causing severe pain and inflammation.
Symptoms and diagnosis
- Pain - Diffuse pain involving the joint- severity of which depends on the amount of cartilage damage. If the severity of the articular cartilage damage is more then its quite disabiling for the patients and hampers patients activities of daily living.
- Swelling - can occur due to inflammation in response to trauma
- Locking or sudden catching of the joint if a loose piece of cartilage gets stuck between the moving joint surfaces.
On examination there may be swelling of the joint, joint movements may be restricted.
Investigations
Subtle injuries to the articular cartilage are often difficult to diagnose.
- Plain X-rays are not usually adequate in diagnosing articular cartilage problems but are usually taken to rule out associated problem like arthritis.
- Definitive diagnosis requires evaluation with MRI or arthroscopy.
Treatment
Initial treatment involves rest and analgesics for the relief of pain with supervised physiotherapy.
Since the cartilage injuries have very poor healing capacity treatment and prognosis depends on the size of the defect.
For smaller articular cartilage defects which are asymptomatic, surgery may not be required.
1. Smaller Defects :
Defects smaller than 2 cm have the best prognosis. Treatment of such defects include arthroscopic surgery involving drilling and causing microfractures(creating small holes). This procedure stimulates healing response by marrow cells that produce cartilage at the area of the defect almost similar to the native cartilage.
Microfracture procedure: Multiple drill holes are created to stimulate cartilage healing by bone marrow
2. Larger defects:
For slightly larger defects, it may be necessary to transplant cartilage from other areas of the knee called mosaicplasty/OATS- Osteochondral autograft transfer.
3. Larger defects:
For very large defects, it is necessary to harvest the patients cartilage cells in the 1st stage operation which are then cultured followed by implantation of these cells about 3 weeks later. This procedure is called autologous chondrocyte implantation(ACI).
Autologous Chondrocyte implantation(ACI)