Basilar joint arthritis of the thumb also known as CMC (Carpal-MetaCarpal) joint arthritis is a condition affecting the joint at the base of the thumb where the metacarpal bone of the thumb and the trapezium bone of the wrist meet. It typically develops as the cartilage on the surfaces of these bones wears away and the joint deteriorates which may lead to symptoms of pain, loss of function, and deformity.
Thumb basilar joint arthritis usually occurs after 40 years of age and affects women more than men. Although the exact cause of this condition is unknown, it is thought that a combination of factors including joint ligament laxity, deformed joints, a prior fracture or injury to the thumb and repetitive stress may contribute to its development.
The joint at the base of the thumb allows for thumb flexion and extension as well as rotational movement. These movements enable the hand to grip things. When basilar joint arthritis of the thumb develops, these motions are impaired. Symptoms of basilar joint arthritis of the thumb may include pain, swelling, bony deformity, and loss of both strength and motion when using the thumbs. Individuals afflicted with this condition often complain of pain with any pinch and grasp activity. Things like opening a jar or turning a doorknob often become increasingly difficult.
To make a diagnosis of basilar joint arthritis of the thumb, the doctor will take a complete medical and clinical history; perform a physical exam and order imaging tests as needed. The doctor will also check for other conditions, such as carpal tunnel syndrome, which are often associated with basilar joint arthritis of the thumb.
Basilar joint arthritis of the thumb in its early stages is often treated conservatively. A non-surgical approach may include activity modifications, oral anti-inflammatory medications, hand therapy, and wearing a brace to support the thumb and take some distress off the damaged joint. If symptoms progress a cortisone injection can be given to provide some relief.
In cases where conservative treatment is no longer effective, surgery may be recommended. Various surgical procedures including joint reconstruction are available. The choice of which surgical procedure to pursue depends on the specifics of the case. Full recovery can take months. Following surgery and wearing a cast for 4-8 weeks, a rehabilitation program will be initiated to restore both strength and function to the hand.