by: Jinsong Wang, MD, PhD
Your thumb accounts for about half of your hand function. Sometimes people don’t realize how important the thumb is until it doesn’t function properly anymore. The most common arthritis involving the thumb is thumb CMC joint arthritis. This is the joint where the thumb attaches to the hand. This joint is sometimes referred to as the basal joint of the thumb. There are several strong, thick ligaments keeping the joint stable. There are also nine muscles that provide dynamic stabilization of the CMC joint. They coordinate to put the thumb in position for optimal function.
What are the causes?
Degenerative arthritis develops over a period of several years. It can also be called osteoarthritis or degenerative arthrosis. The wear and tear of the joint comes with daily use. This leads to damage on the cartilage of the joint surface. The cartilage loss can result in bone on bone friction and arthritis. Women are more likely to develop thumb CMC arthritis than men.
What are the symptoms?
Pain is the most common symptom of thumb CMC arthritis. The most common complaints are pain with activities that involve gripping or pinching, swelling and tenderness at the base of the thumb, loss of strength, limited motion and deformity.
How to make the diagnosis?
Doctors will establish the diagnosis by taking your history, performing a clinical examination, and sometimes using x-rays.
What are the treatments?
Treatments can be divided into nonsurgical and surgical treatments.
- Modification of activities which means reducing the activities that are causing symptoms.
- Brace or splint may be prescribed to support the thumb which can be prefabricated or custom made
- Hand therapy can sometimes help to decrease the swelling and pain of the joint.
- Over the counter or prescription anti-inflammatory medication can be used to control the pain.
- An injection of cortisone into the joint can temporarily reduce pain for a period of several weeks to several months.
- CMC joint fusion is designed to fuse two bones that make up the joint into one solid bone. It will create a pain free but motionless joint. It is usually considered for younger patients who use their hands for heavy work.
- Artificial joint replacement with prosthesis is an option- These metal or plastic prostheses are available to replace the thumb CMC joint. However, long term results have not been widely successful.
- Resection joint replacement- The purpose of the surgery is to remove the arthritic joint surfaces of the CMC joint and replace them with a cushion of material that will keep the bones separated. Traditional ligament reconstruction and tendon interposition (LRTI) procedures have been done for many decades. It has a good track record for pain relief of the joint. Newer procedures use alternative cushion materials instead of using patient’s own tendon.
What should I expect after the surgery?
It takes three to four months to recover from thumb CMC joint replacement. Your thumb and wrist will be placed in a thumb spica splint (a splint extending from thumb to forearm) for six weeks. After six weeks, the thumb will be placed in a removable short thumb spica splint. At that time you will start range of motion exercises and be treated by a hand therapist. There will be no restrictions on your hand three to four months from the time of surgery. However, hand strength will take longer to recover.
If you are experiencing any of the symptoms listed above, or you’d like to be seen for another hand issue, call 603.883.0091 to schedule an appointment with one of our fellowship-trained hand and upper extremity specialists!