Articular Cartilage Defects

What is articular cartilage — general information

At least two bones come into contact within any synovial joint. Articular cartilage is the tissue that covers the bony components of the joint.

It has two essential roles:

• Shock absorption, dissipating the forces acting on the joint; it can withstand compression, tension and shear forces.
• Ensuring minimal friction inside the joint.

What is an articular cartilage defect

A cartilage defect is a well-defined area in which the articular cartilage is damaged. Depending on its severity and cause, a cartilage defect can be classified into several grades. The joint most frequently affected by articular cartilage defects is the knee.

Symptoms of an articular cartilage defect

Articular cartilage contains no pain receptors, which means the pain is not directly proportional to the extent of the injury. Some cartilage injuries may therefore cause little pain in certain cases. In general, however, the deeper the lesion, the greater the pain.

Symptoms:

• Non-specific inflammation caused by a joint effusion (fluid building up in the joint)
• Clicking or crackling during movement
• Joint locking caused by loose bodies inside the joint (pieces of cartilage, with or without bone, that have broken away)
• Pain after a period of sitting
• Reduced sporting performance

Conservative treatment of an articular cartilage defect

Conservative treatment can be applied in the acute phase, or some time after the injury appeared. Acute treatment, for minor and usually post-traumatic injuries, consists of the RICE protocol (Rest, Ice, Compression, Elevation):

• Rest: the activity that caused the injury must be stopped. The doctor may recommend using a crutch to avoid loading the affected limb.
• Ice: massage using ice packs for 20 minutes, several times a day, not applied directly to the skin.
• Compression: an elastic bandage to prevent further swelling.
• Elevation of the affected limb above heart level, again to reduce swelling.

If necessary, non-steroidal anti-inflammatory drugs (NSAIDs) can be used to reduce pain and inflammation. Early diagnosis by an orthopaedic surgeon is extremely important.

Surgical treatment of an articular cartilage defect

1. The microfracture technique

This is a surgical procedure in which the body is stimulated to produce articular cartilage in the damaged area. In this procedure, the dense surface layer of the bone is penetrated to expose the deeper layers, which contain cells from the red bone marrow.

Advantages: This is the least invasive of all articular cartilage reconstruction techniques, requiring a single operation that can be performed entirely arthroscopically. It is safe, and the results are positive in the majority of patients.

Disadvantages: The new cartilage covering the defect does not have the same structure as normal articular cartilage, and there are concerns about how well it will last over time.

2. Matrix-assisted chondroplasty

This involves implanting a chondral matrix at the site of the defect, which is then fixed in place with biological products. The chondrocytes (cartilage cells) migrate into this matrix, generating hyaline cartilage with a structure similar to native cartilage.

Advantages: Matrix-assisted chondroplasty is the treatment of choice for large chondral defects. The procedure covers the defect with cartilage of a higher quality than the fibrocartilage generated by microfracture.

As soon as you feel pain, it is advisable to book an appointment with a good orthopaedic surgeon, who will examine you and offer the appropriate solution.