Unilateral post-traumatic osteoarthritis, unspecified knee

This code signifies degenerative joint disease of a single knee, resulting from a prior injury, where the specific side (left or right) is not documented. It represents the long-term sequelae of trauma leading to cartilage breakdown and joint pain in one knee.

Apply this code when documentation clearly states "post-traumatic osteoarthritis" affecting only one knee, but the laterality (left or right) is not specified. This is appropriate when a patient presents with chronic knee pain and imaging confirms osteoarthritis following a history of knee trauma, and the physician's notes do not differentiate the affected side.

• Ensure the documentation explicitly links the osteoarthritis to a prior trauma.
• Avoid using this code if the laterality is known; instead, use M17.31 (right) or M17.32 (left).
• Do not use for primary osteoarthritis or osteoarthritis due to other specified causes.