Derang of post horn of lat mensc due to old tear/inj, r knee

This code signifies a chronic internal derangement of the posterior horn of the lateral meniscus in the right knee, stemming from a previously sustained tear or injury. It indicates that the meniscus is no longer functioning correctly due to the lasting effects of an old traumatic event.

Apply this code when documentation specifies a derangement of the posterior horn of the lateral meniscus in the right knee, explicitly linking it to an old tear or injury. This is appropriate for patients presenting with persistent symptoms such as locking, catching, or instability, where imaging or arthroscopy confirms the chronic nature of the meniscal issue.

• Ensure documentation clearly states "old tear" or "chronic injury" to differentiate from acute meniscal tears.
• Laterality is crucial; this code is specific to the right knee.
• Distinguish from other meniscal derangements (e.g., M23.20-M23.29) based on the specific horn and cause.