Arthritis broadly refers to inflammation of the joint and the most common form of arthritis is osteoarthritis, which is a degenerative joint disease wherein the smooth cartilage inside the joint wears out causing pain.
In advanced cases of arthritis, the bone grinds on bone inside the arthritic joint. When arthritis develops at the small joint at the thumb base it is diagnosed as “Basal Joint Arthritis.”
So what causes arthritis of the thumb and how do you treat it?
The base of the thumb joins with the wrist and the main joint involved is the basilar joint of the thumb, or carpometacarpal (CMC) joint, which provides mobility and stability. This joint comprises of the metacarpal bone in the thumb and the trapezium bone in the wrist. It is responsible for almost all motion in your hand such as twisting, gripping, pinching, writing. Which is why arthritis in the CMC joint will cause pain while performing any function involving these activities.
Arthritis at the base of the thumb generally develops over a period of several years as a result of the natural aging process and the wear and tear from daily use. In many cases, the actual cause of basal joint arthritis may never be determined, but there are certain risk factors that can increase your chance of developing this condition:
Age and gender- Women over 40 years of age are often at a greater risk for developing arthritis of the basal joint. In fact the ratio of females to men affected by this condition is 10 to 1.
Injuries – On occasions basal joint arthritis may be hastened by an injury or fracture, cartilage damage, torn tendons or ligaments in the hand. Even after healing from an injury, the CMC joint can remain weak and is prone to arthritis of the thumb.
Overuse- Repetitive motions of the hand when performing daily activities or for work (mechanics, sewing and factory work) do increase the risk of developing basal joint arthritis. Even hobbies that require repeated use of the thumb like gardening or playing a musical instrument that cause pain in the hand.
What Are The Symptoms Of Basilar Thumb Arthritis?
Some patients with arthritis at the base of the thumb never exhibit any telltale signs, while some have crippling and severe pain at the base of the thumb or the heel of the palm with turning keys, twisting door knobs, holding a cup, opening jar lids or car doors, using a manual can opener or even after long periods of writing. Weather changes, especially when it is cloudy may create pain in the thumb.
There will be swelling at the thumb base, with warmth about the area and it will feel tender to touch. There may be a bump over the joint.
Heavy repetitive work results in a deep ache in the thumb. With arthritis worsening, the strength of pinching gets weaker and thumb remains sore.
Patients suffering from advanced arthritis will feel a grinding or crunching sensation even with small movements of the thumb.
Thumb joint may look enlarged, swollen and feel stiff. Joints towards the tip of the thumb may become looser to make up for the stiffness at the thumb base.
There is some loss of strength when using the thumb and motion will gradually become limited.
Treatment For Arthritis Of The Thumb Base
Arthritis at the base of the thumb also responds to treatment just like arthritis elsewhere in the body. Conservative first line of treatment includes-
Resting the hand and limiting motion or use
Anti-inflammatory pills or injections
Cortisone or steroid injections
With time this degenerative disease may worsen and even traditional treatment options may fail to provide any pain relief, which can limit daily activities. Then surgery may be recommended by your orthopedic specialist as the only option for definitive and complete pain relief along with the recovery of a satisfactory range of motion.
What Happens During and After Surgery?
There are several surgical options available for CMC arthritis. A popular surgical method known as arthroplasty helps to remove the destroyed joint surface that is replaced with a substitute joint. During arthroplasty an incision is made in the forearm and over the arthritic joint, where all or part of the wrist bone is removed and filled in with tendon material that acts as a cushion between the bones. This helps to support and stabilize the base of the metacarpal so that the reconstructed thumb can regain strength gradually.
It is performed as an outpatient procedure under a general anesthetic or arm nerve block. A splint or cast is used to support the thumb for six weeks.
Post-surgery therapy (stretching and strengthening exercises at home) is started during the second six weeks and total recovery time can take between two to three months with many patients making a full return to daily activities of the hand and unlimited use of the thumb after surgery.
*The blog is for general information and educational purposes only regarding musculoskeletal conditions. The information provided does not constitute the practice of medicine or other healthcare professional services, including the giving of medical advice, and no doctor-patient relationship is formed. Readers with musculoskeletal conditions should seek the advice of their healthcare professionals without delay for any condition they have. The use of the information is at the reader’s own risk. The content is not intended to replace diagnosis, treatment or medical advice from your treating healthcare professional.