Derangement of unsp meniscus due to old tear/inj, left knee

This code signifies an internal derangement of the left knee's meniscus, specifically attributed to a prior tear or injury that has since become chronic. It indicates a persistent functional impairment or mechanical issue within the knee joint stemming from an older meniscal insult.

Apply this code when documentation clearly states a derangement of the left knee meniscus due to an old or chronic tear or injury. This is appropriate for patients presenting with ongoing symptoms such as locking, clicking, or instability, where imaging or clinical history confirms a past meniscal injury as the etiology.

• Ensure documentation specifies "old tear" or "old injury" to differentiate from acute meniscal tears.
• Laterality (left knee) is crucial; do not use for the right or unspecified knee.
• This code is for derangement due to an old tear; acute tears are coded differently (e.g., S83.2-).