M23.21 Derangement of anterior horn of medial meniscus due to old tear or injury

Non-billable header with 3 child codes.

Applies from M23 Internal derangement of knee

Excludes1 (never code together)

• ankylosis (M24.66)
• deformity of knee (M21.-)
• osteochondritis dissecans (M93.2)

Excludes2 (not included here)

• current injury - see injury of knee and lower leg (S80-S89)
• recurrent dislocation or subluxation of joints (M24.4)
• recurrent dislocation or subluxation of patella (M22.0-M22.1)

Applies from M23.2 Derangement of meniscus due to old tear or injury

Applicable to

• Old bucket-handle tear

Codes under M23.21

• M23.211 Derangement of anterior horn of medial meniscus due to old tear or injury, right knee
• M23.212 Derangement of anterior horn of medial meniscus due to old tear or injury, left knee
• M23.219 Derangement of anterior horn of medial meniscus due to old tear or injury, unspecified knee

Code annotations containing back-references to M23.21

Back-references to M23.2

• Type 1 Excludes: S83.2 Tear of meniscus, current injury ("old bucket-handle tear (M23.2)")

Back-references to M23

• Type 2 Excludes: M24.1 Other articular cartilage disorders ("internal derangement of knee (M23.-)")
• Type 2 Excludes: S83 Dislocation and sprain of joints and ligaments of knee ("internal derangement of knee (M23.-)")

Diagnosis Index entries for M23.21

• Derangement › knee (recurrent) › meniscus › due to old tear or injury › medial › anterior horn

Nearby codes

• M23.204 Derangement of unspecified medial meniscus due to old tear or injury, left knee
• M23.205 Derangement of unspecified medial meniscus due to old tear or injury, unspecified knee
• M23.206 Derangement of unspecified meniscus due to old tear or injury, right knee
• M23.207 Derangement of unspecified meniscus due to old tear or injury, left knee
• M23.209 Derangement of unspecified meniscus due to old tear or injury, unspecified knee
• M23.21 Derangement of anterior horn of medial meniscus due to old tear or injury (this code)
• M23.211 Derangement of anterior horn of medial meniscus due to old tear or injury, right knee
• M23.212 Derangement of anterior horn of medial meniscus due to old tear or injury, left knee
• M23.219 Derangement of anterior horn of medial meniscus due to old tear or injury, unspecified knee
• M23.22 Derangement of posterior horn of medial meniscus due to old tear or injury
• M23.221 Derangement of posterior horn of medial meniscus due to old tear or injury, right knee