Thumb CMC arthritis is a common condition that affects millions of people worldwide. The “opposable thumb” that has allowed us to develop fine motor coordination is made possible by the CMC joint, located at the base of the thumb. Also known as the basal joint, it's the most important joint in your hand, allowing you to pinch, manipulate objects, and to grasp items of various sizes. When this joint is painful, tasks that seem so simple, such as writing, turning keys, or buttoning, can become burdensome.
The thumb CMC joint gets most of its stability from ligaments, rather than the bony structure of the joint. These ligaments can stretch after years of use, eventually leading to instability, causing the cartilage of these bones to wear. A form of osteoarthritis, it's a progressive condition caused by wear and tear that can progress to bone on bone pain in the later stages.
In daily life, this joint takes an awful amount of strain since it's used whenever we hold anything in our hand. It often begins to show signs of wear when a person is in their late 40s to early 50s. Both women and men are affected by thumb CMC arthritis, but it's more common in women since they are more likely to have ligament laxity.
There are several options to treat the pain that occurs with thumb CMC arthritis:
1. Splinting: The purpose of wearing a splint is to provide support to the thumb CMC joint, taking some of the strain off of the joint. A good splint will position the thumb so you can easily touch the tip of your thumb to your index finger. Custom splints can be molded directly to your hand by a local hand or occupational therapist. Premade splints come in a variety of options. Typically, splints can be worn during activities that involve thumb use, and can also be worn at night to keep the thumb in a good resting position.
2. Therapy: A local hand or occupational therapist can teach you ways to decrease your pain, techniques to protect your joints, and exercises to prevent stiffness.
3. Cortisone Injections: Your orthopedic surgeon may recommend a cortisone injection to decrease your pain. It's a steroid that is injected directly into the joint to decrease inflammation. Pain relief can vary from person to person. Some report total relief of symptoms while others do not. Talk to your doctor to learn more.
4. Surgery: People decide to have a joint replacement surgery when pain has progressed to the point that it limits function in daily activities. With this procedure, a bone in your wrist (or at least a portion of it) is removed. A strip of muscle or tendon is taken from your forearm and placed in the open space. There are several different versions of this surgery so if you have questions, talk to your doctor.
Details which option you choose, pay attention when you experience thumb pain. Try to limit or avoid activities that require pinching whenever possible. Many adaptive devices have been developed to decrease the pinch force used for activities. Using a pencil grip on your pen or a key adapter on your keys can make your life easier and less painful. Remember that the earlier you seek treatment, the more proactive you can be to prevent it from progressing!