Derangement of lat mensc due to old tear/inj, unsp knee

This code signifies a chronic or pre-existing injury to the outer (lateral) meniscus of the knee, resulting in its structural disorganization or displacement. This derangement is attributed to an old tear or injury, rather than an acute event, and the specific knee (left or right) is not documented.

Apply this code when documentation indicates a patient presents with symptoms related to a long-standing lateral meniscal derangement, and the physician explicitly states it's due to an "old tear" or "old injury." It is appropriate when the medical record does not specify which knee is affected.

• Ensure the documentation clearly distinguishes an "old" or "chronic" injury from an acute one.
• Avoid using this code if the specific knee (left or right) is identified; instead, use the more specific M23.261 or M23.262.
• Consider additional codes for associated conditions, such as osteoarthritis (M17.-) if present.