Thumb carpometacarpal joint

Looks like

The saddle-shaped joint at the base of the thumb, between the first metacarpal and a small wrist bone (the trapezium).

What it does

Lets the thumb swing across the palm to meet each fingertip.

Keeping it well

The hand joint whose wear hurts most often (the fingertip joints wear out more often but hurt less), especially in women after menopause: aching when opening jars. Splints, exercises and injections help.

Related conditions

• Carpal tunnel syndrome
• De Quervain's tenosynovitis
• Dupuytren's contracture & trigger finger
• Ganglion cyst
• Gout
• Haemophilia & bleeding disorders
• Juvenile idiopathic arthritis
• Lyme disease
• Marfan syndrome & connective tissue disorders
• Osteoarthritis
• Pseudogout (calcium pyrophosphate disease)
• Psoriatic arthritis
• Raynaud's phenomenon
• Repetitive strain & overuse injury
• Rheumatic fever & rheumatic heart disease
• Rheumatoid arthritis
• Systemic lupus erythematosus
• Temporomandibular joint disorder