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Carpometacarpal osteoarthritis

What is Carpometacarpal Osteoarthritis? 


Osteoarthritis (OA) of the carpometacarpal (CMC) joints is a type of joint disease of the hand that results from breakdown of joint cartilage and the underlying bone. Moving your fingers or thumb causes an increase in pain, which eases when movement stops. 



  • Pain: Usually felt as a sharp or aching pain at the base of the finger or thumb. The pain is usually worse during movement and relieved by rest.

  • Reduced grip strength: It may be difficult to grip or pick up objects.

  • Stiffness: Following periods of rest (eg in mornings).

  • Swelling: Around the base of the finger or thumb. 

  • Muscle Weakness and Instability



There are many factors that can increase the risk of the developing OA; for example it is more common in females over the age of forty, and is more likely to develop in a joint that has had a previous CMC joint arthritis injury or operation.

When OA develops in a joint, the cartilage gradually roughens and becomes thin, and the bone underneath thickens. The bones at the edge of the joint grow outwards in bony ‘spurs’ and excess synovial fluid can be produced, causing the joint to swell. This can mean that you avoid using these joints, subsequently causing the surrounding muscles to weaken. 



There are several approaches to treating CMC OA, including: 

  • Medications (pain relief) 

  • Splints (restrict movement) 

  • Surgery (if necessary and supported by your doctor) 

  • Lithotripsy shockwave therapy (reduce spurs, increase circulation and recovery, non-invasive) 


Other approaches include:

  • Try applying heat or cold to the painful area for 15 minutes. Always have a layer (such as a tea towel) between your skin and the heat or ice pack. You can repeat this whenever you need to throughout the day. Make sure the temperature of the skin returns to normal in between applying heat or ice packs to prevent damage to the tissues or skin.

The following are joint protection techniques that may help to reduce the pain you experience when doing activities and prevent further damage to the joints:

  • Take notice of any pain you feel, it can serve as a warning that the way you are performing the activity is causing damage to the joint.

  • Spread the load over several joints (eg by carrying items on two flat hands rather than gripping with your thumb).

  • Use larger stronger joints rather than putting the strain through the affected joints.

  • Use less effort (e.g. push or slide heavy items rather than carrying).


Sources and Related Links

OA MC Joint Image 1 (Gray).png

Henry Vandyke Carter, Public domain, via Wikimedia Commons

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