Articular cartilage

Looks like

A smooth, glossy layer a few millimetres thick covering the ends of the thigh bone, shinbone and the back of the kneecap.

What it does

Lets the joint glide with almost no friction and spreads the load.

Keeping it well

It has no blood supply and heals poorly. Staying active and losing excess weight protect it; a knee that locks or swells after exercise needs assessment.

Related conditions

• ACL & meniscus injury
• Baker's (popliteal) cyst
• Chronic venous insufficiency
• Gout
• Growing pains
• Haemophilia & bleeding disorders
• Juvenile idiopathic arthritis
• Lyme disease
• Lymphatic filariasis (elephantiasis)
• Lymphoedema
• Marfan syndrome & connective tissue disorders
• Osteoarthritis
• Pseudogout (calcium pyrophosphate disease)
• Psoriatic arthritis
• Reactive arthritis
• Restless legs syndrome
• Rheumatic fever & rheumatic heart disease
• Rheumatoid arthritis
• Runner's knee (patellofemoral pain)
• Septic arthritis
• Systemic lupus erythematosus
• Temporomandibular joint disorder
• Varicose veins