M18: Arthrosis of first carpometacarpal joint
M18.9: Arthrosis of first carpometacarpal joint, unspecified
The saddle joint of the thumb is the joint between the metacarpal bone of the thumb and one of the carpal bones. The hand is made up of a number of small bones. Below, at the wrist, are the carpal bones. Next along are the metacarpal bones. These are in the palm area. Each finger has a metacarpal bone. The finger bones begin after the metacarpal bones.
With arthrosis, the cartilage in the joint wears away. Cartilage covers the end of the bones that are connected to one another in the joint. Its smooth surface prevents the bones from rubbing against one another. With advancing age, the cartilage can wear away. This can happen more quickly if a joint is subjected to greater loads than usual.
Arthrosis can be accompanied by typical symptoms, such as pain in the joint. It may also no longer be possible to move the joint as usual.
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