Trapeziometacarpal (TMC) arthritis ( also known as Rhizarthrosis ) is arthritis of the first carpometacarpal (CMC) joint of the thumb. The CMC joint of the thumb, or TMC joint plays a critical role in the normal functioning of the thumb. It is the most important joint connecting the wrist to the metacarpus. Osteoarthritis of the TMC is a severely disabling condition; up to twenty times more common among elderly women than in average.
Causes of TMC arthritis are:
- Excessive repetitive use of the CMC joint of the thumb
- Lesion of the ligaments or a fracture.
- Laxity of the CMC joint (can be hereditary, increased risk for ligament injuries, a primary stimulus in the development of arthritis. Also causes a hyperextension, which is another primary stimulus for the development of arthritis.
- Weakness of the cross links of the fingers (ligg. oblique anterior). These ligaments are the most important stabilisers of the fingers. 
- Using thumb in occupation eg Work-related thumb pain in physiotherapists is a prevalent problem among physiotherapists who administer manual techniques. Factors that appear to be associated with thumb pain include CMC mobility and thumb strength.
Signs and Symptoms
The first signs of arthritis in the thumb are
- pain, tenderness, and stiffness at the base of your thumb. This occurs with gripping, pinching, or clasping something between the thumb and index fingers or when a mild force, such as when you twist a key in a lock or turn a door handle. An ache after activity can also be a feature.
- Decreased strength and range of motion eg opening jars or doing up buttons may become difficult.
- Appearance. The joint may become swollen or develop a bony bump. The joint may appear squarish and enlarged.
- Noticeable lumps or swelling on the first CMC joint
- Thumb CMC grind test
- Plain radiographs showing degenerative changes (bone spurs, thinning of cartilage, loss of joint space) in affected joints are usually diagnostic.
Conservative measures are the first options for CMC arthritis and can ameliorate symptoms in most cases. These include
eg Try to avoid: clenching your hands when carrying things; repetitive movements that involve pinching or twisting
- range-of-motion and stretching exercises to improve thumb motion.
- Advance to include strength exercises for the thumb and fingers.
- Dexterity and fine motor exercises for the hand and thumb. 
- Application of therapeutic heat or cold
- Application of electro therapeutic techniques eg Therapeutic US, TENS. US has been found to have the ability to evoke a broad range of therapeutically beneficial such as improved pain and functional outcomes, positive cartilage healing properties and positive phonophoresis for hyaluronan. 
- Acupuncture. May work in pain relief for some people.
- Splinting, designed to help reduce pain, prevent deformity, or prevent deformity from getting worse. To wear at night, during flare ups and when doing heavy work with hand.
- Clinical trials have provided evidence that a combination of joint mobilization, neural mobilization, and exercise helps with CMC joint pain.
- Topical medications, such as capsaicin or diclofenac, which are applied to the skin over the joint
- Over-the-counter pain relievers, such as acetaminophen, ibuprofen or naproxen sodium
- Prescription pain relievers, such as celecoxib (Celebrex) or tramadol (Conzip, Ultram)
- Injections. Corticosteroid injections can offer temporary pain relief and reduce inflammation.
If the diagnosis of ‘rhizarthrosis’ is determined too late, none of the above treatments will be helpful. Because of severe pain and movement restriction, surgery could be inevitable.
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