Why does the base of my thumb hurt?
The thumb provides nearly half of the important fine motor function of the hand. Because of this, problems with the thumb can severely impact our daily activities. Many patients come in complaining of pain around the base of the thumb. When this happens, it is our job to tease out what exactly this could be coming from. Common things being common, an adult over 40 years of age with pain at the base of the thumb likely has basal thumb arthritis, also known as thumb CMC joint arthritis. Symptoms often include swelling to the base of the thumb and pain with gripping activities that gradually worsens over time.
Another disease that presents similarly and therefore needs to be considered as another potential cause of the symptoms is tendinitis in the tendon compartment at the base of the thumb. This is called De Quervain's tenosynovitis. This is a fancy term for inflamed tendons along the area right next to the base of the thumb. This condition is much more common in females at childbearing age and is often referred to as newborn mothers disease. Repetitive activities such as lifting a newborn can cause inflammation of the tendons along the side of the wrist just next to the base of the thumb.
Occasionally, these disease processes can occur at the same time. The way we determine which of these diseases could be causing your pain at the base of the thumb is through history, physical exam and X-rays.
Basal thumb arthritis will show loss of joint space at the thumb CMC joint on X-rays, a positive CMC grind test (which is a test for pain that occurs with pushing in on the thumb while rotating it around), and swelling/tenderness at the CMC joint.
De Quervain's tenosynovitis will often show pristine joint space on X-rays, a negative CMC grind test, a positive Finklestein test (which is a test for pain when placing the thumb inside a closed fist and bending the wrist sideways), and swelling/tenderness along the side of the wrist, just above the base of the thumb.
Treatment for both diseases begins with conservative management. This often includes bracing and steroid injections into the affected area. Many patients get relief from these treatment measures. For De Quervain's tenosynovitis specifically, the majority of patients can be cured with one or two injections. A small number of patients do not get cured with these measures. At that point, there is a reliable minor surgery to release the pressure on these tendons that has low risk and excellent outcomes.
With basal thumb arthritis, the conservative treatments do not cure the disease but can make patients feel good enough to tolerate the disease without having to have surgery. If these measures do not provide enough relief, there are surgical treatments that are very reliable and have excellent outcomes.
If you are having pain at the base of your thumb, come on in and let us help you with that!
