Thumb arthritis, also known as CMC arthritis or basal joint arthritis, is a painful condition that develops when the joint at the base of the thumb wears down, often due to aging. This joint, called the carpometacarpal (CMC) joint, is where the thumb bone (metacarpal) meets the wrist bone (carpal).
Understanding the CMC Joint
The CMC joint is crucial for thumb movement, allowing you to pinch, grip, and perform many everyday tasks. The reference specifies that as this joint becomes worn, often due to age, it can lead to a painful condition called thumb arthritis (also known as CMC arthritis or basal joint arthritis).
Key Aspects of Thumb Arthritis
Here's a breakdown of important aspects to understand about thumb arthritis:
- Location: Occurs at the base of the thumb, where the thumb connects to the wrist (the CMC joint).
- Cause: Primarily caused by wear and tear of the joint cartilage, often associated with aging.
- Symptoms:
- Pain at the base of the thumb, especially with gripping or pinching.
- Stiffness and tenderness in the thumb joint.
- Decreased range of motion.
- Swelling around the base of the thumb.
- A bony bump or enlargement at the joint.
- Alternative Names: Also known as CMC arthritis or basal joint arthritis.
How Thumb Arthritis Develops
The development of thumb arthritis can be visualized as follows:
| Stage | Description |
|---|---|
| Normal Joint | Healthy cartilage cushions the bones in the CMC joint, allowing for smooth movement. |
| Arthritis | Over time, the cartilage wears away, causing the bones to rub directly against each other. This leads to pain, stiffness, and inflammation. |
In Summary
Thumb arthritis is a degenerative condition affecting the CMC joint at the base of the thumb, primarily caused by the breakdown of cartilage due to aging and overuse. It results in pain and reduced function, impacting daily activities that rely on thumb movement.
