ICD-10-CM > M00-M99 > M20-M25 > M23 > M23.3 > M23.31 M23.31 Other meniscus derangements, anterior horn of medial meniscus Non-Billable/Non-Specific Codes M23.311Other meniscus derangements, anterior horn of medial meniscus, right kneeM23.312Other meniscus derangements, anterior horn of medial meniscus, left kneeM23.319Other meniscus derangements, anterior horn of medial meniscus, unspecified knee