Knee

Looks like

The largest joint: two rounded bone ends, two cartilage cushions, four ligaments, and the kneecap in front.

What it does

A hinge that carries several times body weight and locks straight to save effort.

Keeping it well

Strong thighs, weight control, cycling and swimming. Swelling within an hour of a twist means something tore.

Its parts

• Skin of knee
• Patella
• Anterior cruciate ligament
• Posterior cruciate ligament
• Collateral ligaments
• Menisci
• Articular cartilage
• Patellar & quadriceps tendon
• Popliteal fossa & artery
• Patellar part of right knee
• Patellar part of left knee
• Anterior tibial recurrent artery
• Anterior tibial vein
• Genicular vein
• Inferior lateral genicular artery
• Lateral superior genicular artery
• Arcuate popliteal ligament
• Articular capsule of knee joint
• Infrapatellar fat pad
• Oblique popliteal ligament
• Transverse ligament of knee
• Anserine bursa
• Deep infrapatellar bursa
• Inferior subtendinous bursa of biceps femoris muscle
• Lateral patellar retinaculum
• Lateral subtendinous bursa of gastrocnemius muscle
• Medial patellar retinaculum
• Medial subtendinous bursa of gastrocnemius muscle
• Semimembranosus bursa
• Subcutaneous bursa of tuberosity of tibia
• Subcutaneous infrapatellar bursa
• Subcutaneous prepatellar bursa
• Subfacial prepatellar bursa
• Subtendinous bursa of sartorius muscle
• Subtendinous prepatellar bursa
• Superior bursa of biceps femoris muscle
• Suprapatellar bursa

Related conditions

• ACL & meniscus injury
• Acromegaly
• Baker's (popliteal) cyst
• Chronic venous insufficiency
• Clotting disorders (thrombophilia & APS)
• Deep vein thrombosis
• Fractures
• Fragility fracture
• Frailty & falls in older age
• Gout
• Growing pains
• Haemophilia & bleeding disorders
• High blood pressure
• High cholesterol
• Hyperparathyroidism
• Hypothermia & frostbite
• Juvenile idiopathic arthritis
• Kawasaki disease
• Lyme disease
• Lymphatic filariasis (elephantiasis)
• Lymphoedema
• Marfan syndrome & connective tissue disorders
• Metabolic syndrome
• Orthostatic hypotension & POTS
• Osgood–Schlatter disease
• Osteoarthritis
• Osteogenesis imperfecta (brittle bone disease)
• Osteomalacia & rickets
• Osteomyelitis (bone infection)
• Osteoporosis
• Paget's disease of bone
• Peripheral artery disease
• Phaeochromocytoma & hyperaldosteronism
• Pre-eclampsia
• Pseudogout (calcium pyrophosphate disease)
• Psoriatic arthritis
• Raynaud's phenomenon
• Reactive arthritis
• Restless legs syndrome
• Rheumatic fever & rheumatic heart disease
• Rheumatoid arthritis
• Runner's knee (patellofemoral pain)
• Sarcoma
• Sepsis
• Septic arthritis
• Shock (circulatory failure)
• Systemic lupus erythematosus
• Temporomandibular joint disorder
• Tendinopathy (tennis & golfer's elbow, Achilles, patellar)
• Varicose veins
• Vasculitis (GCA & others)
• Vitamin B1, C and other deficiencies
• Vitamin D deficiency