Oth unil sec osteoarth of 1st carpometacarp joint, unsp hand

This code signifies a degenerative joint disease affecting the base of the thumb on one side, specifically the joint between the trapezium bone and the first metacarpal bone. It indicates that the osteoarthritis is a consequence of another underlying condition, rather than primary osteoarthritis, and the specific hand affected is not documented.

Apply this code when documentation specifies unilateral secondary osteoarthritis of the first carpometacarpal joint, but does not specify whether it is the right or left hand. This typically occurs when the physician notes "secondary CMC OA, unspecified hand" or similar. Supporting documentation should clearly indicate the secondary nature of the osteoarthritis.

• Always attempt to clarify with the provider if the affected hand (right or left) can be specified for a more precise code.
• Ensure documentation explicitly states "secondary" osteoarthritis; otherwise, a primary osteoarthritis code may be more appropriate.
• Sequence this code after the underlying condition causing the secondary osteoarthritis, if known and documented.