The wrist and thumb

15/05/2018

The wrist consists of several joints giving it its extensive mobility. It can be injured following a fall or if it is twisted excessively, causing a sprain, dislocation or fracture. It can also suffer from osteoarthritis, a degenerative disease that primarily affects the thumb.

The wrist joint connects the ends of the two bones of the forearm (radius and cubitus) to the eight carpal bones, arranged in two rows and held in place by a thick tendon. The wrist also has numerous small muscles and ligaments, allowing it to be flexed and rotated in all directions.

Traumatic conditions

The wrist is one of the most frequently injured joints. The most common cause of injury is falling with the hand outstretched. This can cause sprains of variable severity, from mild, with stretching of one or more of the ligaments connecting the carpal bones, to severe, with rupture of the ligaments. Applying ice reduces oedema (swelling), painkillers alleviate pain and immobilisation using a splint helps the sprain recover by resting the joint.

The wrist can also be broken at the extremity of the radius, causing painful swelling and sometimes deformity. This type of fracture is more common in adolescents, as well as for the over 50s. It requires immobilisation for 4 to 6 weeks, sometimes following surgery. The wrist can also be broken at the scaphoid bone, one of the carpal bones. Treatment may require a plaster cast or surgery and the use of a splint.

Inflammatory conditions

The wrists can be the site of tendinitis, particularly in sports enthusiasts or in manual workers performing repetitive tasks. De Quervain’s tenosynovitis is a painful inflammation of the thumb tendons, common in tailors, mechanics and secretaries. It usually resolves following resting of the thumb, the use of a splint and anti-inflammatory medication.

Carpal tunnel syndrome particularly affects pregnant women and women over the age of 50. It is caused by compression of a nerve located in a tunnel in the carpal bone area, promoted by repetitive movements or prolonged pressure. It causes pain and tingling in the fingers. Medical treatment and wearing a splint at night may be enough to alleviate the condition, but surgery may also be necessary in the event of loss of sensation or motricity.

Osteoarthritis

Like all types of osteoarthritis, osteoarthritis of the wrist and thumb (rhizarthrosis) is caused by progressive wear and tear of the cartilage protecting the joint. It generally occurs to the over 50s - to women in 90% of cases - and causes painful flare-ups. It is treated by applying heat, painkillers and anti-inflammatories, resting using a splint and surgery in certain severe cases.