Cystic meniscus, unspecified lateral meniscus, left knee

This code signifies the presence of a fluid-filled sac (cyst) within the lateral meniscus of the left knee, where the specific type or cause of the cyst is not documented. It indicates a structural abnormality of the meniscal cartilage on the outer side of the knee joint.

Use this code when documentation clearly states a cystic lesion of the left lateral meniscus, but the physician does not specify further details about the cyst's nature (e.g., degenerative, traumatic). This code is appropriate when imaging reports (MRI) or arthroscopic findings confirm a lateral meniscal cyst without additional clarifying information.

• Ensure the documentation specifies "left knee" and "lateral meniscus" to avoid laterality or anatomical site errors.
• If the type of cystic meniscus is known (e.g., degenerative, traumatic), a more specific code from the M23.0 subcategory should be used.
• Always review operative reports or imaging findings for more precise details that might allow for a more specific code assignment.