Right patella

Looks like

The kneecap: a flat triangular bone embedded in the tendon at the front of the knee.

What it does

Acts as a pulley, increasing the leverage of the thigh muscle that straightens the knee, and shields the joint.

Keeping it well

Pain around it on stairs or squatting (patellofemoral pain) is common and eases with exercise; a kneecap that slips out needs assessment.

Related conditions

• ACL & meniscus injury
• Acromegaly
• Baker's (popliteal) cyst
• Chronic venous insufficiency
• Fractures
• Fragility fracture
• Frailty & falls in older age
• Growing pains
• Hyperparathyroidism
• Juvenile idiopathic arthritis
• Lymphatic filariasis (elephantiasis)
• Lymphoedema
• Osteogenesis imperfecta (brittle bone disease)
• Osteomalacia & rickets
• Osteomyelitis (bone infection)
• Osteoporosis
• Paget's disease of bone
• Pseudogout (calcium pyrophosphate disease)
• Reactive arthritis
• Restless legs syndrome
• Runner's knee (patellofemoral pain)
• Sarcoma
• Septic arthritis
• Varicose veins
• Vitamin B1, C and other deficiencies
• Vitamin D deficiency